A safety supervision method for the use of exemption-level radioactive sources based on RFID

Abstract

The present invention discloses a safety supervision method for the use of exempt radioisotope sources based on RFID, specifically relating to the technical field of radioisotope source use supervision, including: affixing an RFID tag to each radioisotope source container in the exempt radioisotope source storage cabinet and writing initial data, reserving a digital fingerprint field. Detect the energy spectrum diagram of each radioisotope source one by one, extract the characteristic energy distribution and peak value, convert them into digital expressions and upload them to the data management center. Perform binary hashing processing on the digital data to obtain a digital fingerprint and write it into the RFID tag. When the staff performs a removal operation, read the RFID data through the reader and upload it to update the status of the radioisotope source. During the storage operation, detect the characteristic energy data of the radioisotope source to be stored and trigger digital fingerprint verification. If the verification passes, storage is allowed; if it fails, determine whether it is a misplacement or source replacement, and update the status of the radioisotope source according to the result.

Description

Technical Field

[0001] The present invention relates to the technical field of the supervision of the use of radiation sources. More specifically, the present invention relates to a method for the safe supervision of the use of exempt-level radiation sources based on RFID. Background Art

[0002] Exempt-level radiation sources are radiation sources whose radioactive activity does not reach the minimum limit specified in the "Classification Method of Radiation Sources" and will not cause significant radiation damage to the human body after long-term exposure. However, due to the particularity of the radiation sources themselves, strict management should still be carried out during use to prevent misuse and random placement, which may be accessed by non-staff members and pose potential safety hazards. Traditional management methods for exempt-level radiation sources usually rely on manual registration and simple physical markings, such as labels and log records. However, this management method has many defects, mainly manifested as omissions in manual operations and insufficient real-time monitoring of the status of radiation sources. In many cases, radiation sources may be accidentally replaced or misplaced due to frequent personnel contact, access operations, etc. In addition, due to the lack of an effective tracking and authentication mechanism, it is difficult to record the usage status of radiation sources in real time and accurately, which may make it difficult to trace responsibilities and handle source management problems in case of accidents. Based on these deficiencies, the existing management methods fail to effectively prevent misplacement or source replacement attacks and cannot ensure the safety and compliance of radiation sources during use.

[0003] Therefore, how to analyze based on the characteristics of the radiation source itself, fuse its radiation characteristics detection with RFID tag technology, and implement a method for the safe supervision of the use of exempt-level radiation sources based on RFID to supervise misplacement or source replacement attacks during use and ensure the safety and compliance of radiation sources during use is an urgent problem to be solved.

[0004] To solve the above problems, a technical solution is provided as follows. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a method for the safe supervision of the use of exempt-level radiation sources based on RFID to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] S1: Attach an RFID tag to each radiation source container in the storage cabinet for exempt-level radiation sources and write the initial data, while reserving a digital fingerprint field;

[0008] S2: Detect the energy spectrum diagram of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum diagram, convert the characteristic energy distribution and peak value into digital expressions, and upload them to the data management center;

[0009] S3: After performing binary hashing with retained similarity on the digital expressions of the characteristic energy distribution and peak values, obtain the digital fingerprint corresponding to the radiation source, and write the digital fingerprint into the digital fingerprint field reserved in the RFID tag;

[0010] S4: When the staff performs the removal operation, the reader reads the RFID tag data through the opening and closing control of the storage cabinet door and uploads it. Based on the uploaded data, the removed radiation source is screened out, and the status of the corresponding radiation source is modified to removed;

[0011] S5: When the staff performs the storage operation, detect the characteristic energy distribution and peak value data of the radiation source to be stored, and trigger digital fingerprint verification;

[0012] S6: Perform digital fingerprint verification on the radiation source to be stored, and calculate the digital fingerprint recognition difference degree of the radiation source to be stored;

[0013] S7: Retrieve the historical records of the attenuation of the characteristic energy distribution after each radiation source is used up, and set the dynamic digital fingerprint recognition difference degree threshold;

[0014] S8: Based on the digital fingerprint recognition difference degree of the radiation source to be stored, determine whether the digital fingerprint verification passes. If so, allow the radiation source to be stored. If not, further determine whether the radiation source to be stored is misclassified or source replaced, and modify the radiation source status according to the judgment result.

[0015] In a preferred embodiment, in S1, attach an RFID tag to each radiation source container in the exemption-level radiation source storage cabinet and write the initial data, and at the same time reserve a digital fingerprint field, which specifically includes:

[0016] Obtain all the radiation source containers in the exemption-level radiation source storage cabinet, select an active RFID tag with long-distance recognition ability, and attach the RFID tag to the surface of the radiation source container;

[0017] Assign a unique identifier to the RFID tag of each radiation source container, and use an RFID programming device to write the initial data into the tag storage area. The initial data includes the radiation source type, activity value, and radiation source status;

[0018] Reserve a space in the RFID tag storage area for storing the digital fingerprint field of the radiation source, and set the initial value of this field to be empty.

[0019] In a preferred embodiment, in S2, detect the energy spectrum diagram of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum diagram, and upload the digital expressions of the characteristic energy distribution and peak value to the data management center, which specifically includes:

[0020] Based on the type of exempted radioactive sources, a lightweight energy spectrum detection instrument with the required monitoring energy range is selected, and the energy spectrum detection instrument is calibrated using a standard energy source;

[0021] Use the energy spectrum detection instrument to perform one-by-one detection of the radioactive sources in the exempted radioactive source storage cabinet, obtain the energy spectrum of each radioactive source, extract the characteristic energy distribution and peak value in the energy spectrum of the radioactive source and convert it into a digital expression:

[0022] The energy signal of the extracted characteristic energy distribution is quantized into a discrete digital signal through analog-to-digital conversion, and each energy point corresponds to a count value;

[0023] The local maximum value of each up and down cycle in the characteristic energy distribution is extracted by the sliding window method and marked as the energy peak value, and the peak energy point and count value corresponding to the energy peak value, as well as the full width half maximum value, are obtained;

[0024] The digital expression of characteristic energy distribution and peak value is recorded, and the digital expression is converted into a structured storage format and uploaded to the data management center.

[0025] In a preferred embodiment, in S3, the digital expressions of the characteristic energy distribution and the peak value are subjected to binary hash processing with similarity retention to obtain a digital fingerprint corresponding to the radiation source, and the digital fingerprint is written into a digital fingerprint field reserved in the RFID tag, specifically including:

[0026] The digital expression of characteristic energy distribution and peak value corresponding to each radiation source is obtained at the data management center, and the digital expression data is converted into a character string without any symbol information;

[0027] The string is processed using a binary hash algorithm that retains similarity to obtain a unique digital fingerprint of a fixed length, which is then written into the digital fingerprint field in the RFID tag storage area using an RFID programming device.

[0028] In a preferred embodiment, in S4, when the staff performs the removal operation, the RFID tag data is read and uploaded by the reader of the storage cabinet door opening and closing control, and the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to be removed, which specifically includes:

[0029] Install a staff identification system on the door of the storage cabinet. After the staff has confirmed their identity, they can choose to deposit or withdraw.

[0030] An RFID reader is provided in the radioactive source storage cabinet, and a control element connected to the door of the storage cabinet is built in;

[0031] If the staff member selects the removal operation, the RFID tag on the radioactive source container in the storage cabinet is scanned once when the cabinet door is opened and once when it is closed to read the tag data, and the RFID tag data with the read timestamp is uploaded and updated to the data management center;

[0032] The data management center compares the two pieces of data received, marks the status of the radioactive source in the RFID tags with missing second upload tag data as removed, and takes the timestamp of the cabinet door opening as the removal time of the radioactive source.

[0033] In a preferred embodiment, in S5, when the staff member performs the deposit operation, detecting the characteristic energy distribution and peak data of the radioactive source to be deposited, triggering the digital fingerprint verification specifically includes:

[0034] If the staff member selects the deposit operation, use a lightweight energy spectrum detection instrument to detect the radioactive source to be deposited, obtain the characteristic energy distribution and peak data in the energy spectrum diagram of the radioactive source to be deposited, upload the data to the data management center, and trigger the digital fingerprint verification at the same time.

[0035] In a preferred embodiment, in S6, performing digital fingerprint verification on the radioactive source to be deposited, calculating the digital fingerprint recognition difference degree of the radioactive source to be deposited specifically includes:

[0036] Recalculate the digital fingerprint corresponding to the radioactive source to be deposited in the data management center, and mark this fingerprint as the comparison fingerprint;

[0037] Based on the unique identifier of the RFID tag corresponding to the radioactive source to be deposited in the data management center, retrieve the digital fingerprint stored in the corresponding digital fingerprint field, and calculate the Hamming distance between the digital fingerprint and the comparison fingerprint;

[0038] Mark the ratio of the Hamming distance to the digital fingerprint length as the digital fingerprint recognition difference degree of the radioactive source to be deposited.

[0039] In a preferred embodiment, the unique identifier of the RFID tag corresponding to the radioactive source, retrieve the digital fingerprint change history record of this radioactive source in the data management center;

[0040] Group and statistically analyze the retrieved digital fingerprint change history records according to the interval time between removal and return, and calculate the average value of the digital fingerprint recognition difference degrees of the digital fingerprint verification passed records in each statistical group;

[0041] Obtain the interval time between removal and return of the current radioactive source to be deposited, perform historical mean matching of the digital fingerprint recognition difference degree, set the acceptable range of the recognition deviation, and comprehensively determine the dynamic digital fingerprint recognition difference degree threshold of the radioactive source to be deposited.

[0042] In a preferred embodiment, in S8, based on the digital fingerprint recognition difference degree of the radiation source to be stored, it is judged whether the digital fingerprint verification passes. If so, the radiation source to be stored is allowed to be stored. If not, it is further judged whether the radiation source to be stored is misplaced or source replaced. Modifying the radiation source status according to the judgment result specifically includes:

[0043] Based on the set dynamic digital fingerprint recognition difference degree threshold, if the recognition difference degree calculated by the radiation source to be stored in the digital fingerprint verification is less than the recognition difference degree threshold, it is judged that the digital fingerprint verification passes. At this time, the storage cabinet door is opened to allow the radiation source to be stored, and the radiation source status is marked as placed and the placement time is recorded at the same time;

[0044] The comparison fingerprint in the recognition process is updated as the new digital fingerprint into the digital fingerprint field in the RFID tag;

[0045] If the recognition difference degree calculated by the radiation source to be stored in the digital fingerprint verification is greater than or equal to the recognition difference degree threshold, it is judged that the digital fingerprint verification fails, and the radiation source to be stored is prohibited from being stored in the storage cabinet;

[0046] Retrieve and extract the digital fingerprints with the radiation source status marked as taken out in all RFID data in the data management center, and integrate them into a digital fingerprint group;

[0047] Calculate the recognition difference degree between the comparison fingerprint with failed digital fingerprint verification and the digital fingerprint group one by one. If there is a digital fingerprint with a recognition difference degree less than the set recognition difference degree threshold in the calculation result, mark the radiation source status corresponding to the compared and the compared digital fingerprints as misplaced;

[0048] If there is no digital fingerprint with a recognition difference degree less than the set recognition difference degree threshold in the digital fingerprint group, mark the status of the radiation source to be stored as suspected source replacement and send an alarm message.

[0049] The technical effects and advantages of a method for safely supervising the use of exempt-level radiation sources based on RFID according to the present invention:

[0050] By attaching RFID tags to each radiation source and writing digital fingerprints into them, precise identification and tracking of radiation sources can be achieved, ensuring that the origin, status, and location of radiation sources are always traceable. The generation of digital fingerprints is based on the characteristic energy spectrum data of radiation sources, which is highly stable and unique, not easily tampered with or forged, thus effectively avoiding source substitution attacks and illegal operations. The digital expression of energy spectrum data and its hashing process ensure the secure storage and transmission of radiation source information, enabling the verification of radiation sources at any time and promptly detecting and preventing misoperations or improper access. By combining RFID tags with digital fingerprint verification, when a radiation source is taken out or deposited, the system can identify it in real time and update its status, enhancing the automation and intelligence levels of radiation source management.

[0051] This method not only improves the management efficiency of radiation sources, reduces the risk of human intervention, but also provides strong data support for safety supervision, ensuring that the use of exempt-level radiation sources complies with strict safety requirements and can significantly enhance the safety and reliability of radiation source management. Brief Description of the Drawings

[0052] Figure 1 Schematic diagram of a safety supervision method for the use of exempt-level radiation sources based on RFID according to the present invention. Detailed Embodiments

[0053] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment 1:

[0054] Figure 1 A safety supervision method for the use of exempt-level radiation sources based on RFID according to the present invention is provided, which includes the following steps:

[0055] S1: Attach RFID tags to each radiation source container in the exempt-level radiation source storage cabinet and write initial data, while reserving a digital fingerprint field;

[0056] S2: Detect the energy spectrum diagram of each radiation source one by one, extract the characteristic energy distribution and peak values in the energy spectrum diagram, convert the characteristic energy distribution and peak values into digital expressions, and upload them to the data management center;

[0057] S3: Perform binary hashing processing with retained similarity on the digital expressions of the characteristic energy distribution and peak values to obtain the digital fingerprint corresponding to the radiation source, and write the digital fingerprint into the reserved digital fingerprint field in the RFID tag;

[0058] S4: When the staff performs the removal operation, the reader reads the RFID tag data through the opening and closing control of the storage cabinet door and uploads it. Based on the uploaded data, the removed radiation source is screened out, and the status of the corresponding radiation source is modified to removed.

[0059] S5: When the staff performs the storage operation, the characteristic energy distribution and peak data of the radiation source to be stored are detected, triggering digital fingerprint verification.

[0060] S6: Perform digital fingerprint verification on the radiation source to be stored, and calculate the digital fingerprint recognition difference degree of the radiation source to be stored.

[0061] S7: Retrieve the historical records of the attenuation of the characteristic energy distribution after each radiation source is used up, and set the dynamic digital fingerprint recognition difference degree threshold.

[0062] S8: Based on the digital fingerprint recognition difference degree of the radiation source to be stored, judge whether the digital fingerprint verification passes. If so, allow the radiation source to be stored. If not, further judge whether the radiation source to be stored is misplaced or replaced by a source, and modify the radiation source status according to the judgment result.

[0063] In S1, an RFID tag is attached to each radiation source container in the exemption-level radiation source storage cabinet and the initial data is written, while reserving a digital fingerprint field.

[0064] Obtain all the radiation source containers in the exemption-level radiation source storage cabinet. When selecting the RFID tag, give priority to the active RFID tag with long-distance recognition ability. The active RFID tag has a self-powered function and can communicate effectively with the reader through radio waves within a relatively long distance, ensuring accurate and stable data transmission between multiple radiation source containers in the storage cabinet.

[0065] According to the shape and material of each radiation source container, select a suitable installation method to attach the RFID tag to the surface of the container. The RFID tag needs to be installed in a position that does not affect the function of the radiation source container and ensure that it can be stably read during subsequent operations.

[0066] Assign a globally unique identifier (UID) to each RFID tag. This identifier should correspond to the radioactive source container and can be used to uniquely identify the container in subsequent operations. This identifier needs to correspond one-to-one with the radioactive source information in the database to avoid duplication or conflict. Use an RFID programming device to perform the initial data writing operation on the tag. The initial data should include, but is not limited to, the radioactive source type (such as cobalt-60, cesium-137, etc.), the activity value of the radioactive source (such as in units of becquerel Bq or curie Ci), and the current status of the radioactive source (such as "in storage", "removed"). After writing the initial data, verify the RFID tag to ensure that all data has been successfully stored in the tag storage area. Read the data in the tag through the verification program to ensure that it is consistent with the radioactive source information in the database.

[0067] Reserve a space in the RFID tag storage area for storing the digital fingerprint field of the radioactive source, and set the initial value of this field to be empty.

[0068] In S2, detect the energy spectrum diagram of each radioactive source one by one, extract the characteristic energy distribution and peak values in the energy spectrum diagram, and upload the characteristic energy distribution and peak values to the data management center after converting them into digital expressions.

[0069] Based on the types of exempt radioactive sources, select a lightweight energy spectrum detection instrument with a set required monitoring energy range (flexibly set according to the types of radioactive sources, with a default setting of 500 keV to 1.5 MeV), and calibrate the energy spectrum detection instrument using standard energy sources (such as radioactive sources with known energy spectra like cobalt-60, cesium-137, etc.).

[0070] Use the calibrated energy spectrum detection instrument to detect each radioactive source in the exempt radioactive source storage cabinet one by one. During each detection, place the detection instrument in front of the radioactive source to ensure that the measurement angle and position are appropriate, and obtain the energy spectrum diagram of the radioactive source within the set energy range. Through real-time data acquisition, record the energy distribution diagram of each radioactive source in the instrument memory.

[0071] Use an analog-to-digital converter (ADC) to convert the extracted characteristic energy distribution from an analog signal into a discrete digital signal. Each energy point corresponds to a specific count value (i.e., radiation intensity value) in the digital signal, and these discrete values form a digital general representation of the radioactive source's energy spectrum: (energy point, radiation count value). For example, a radiation count value of 50 at an energy point of 100 keV can be converted into a digital format expression of (100, 50).

[0072] Use the sliding window algorithm to analyze the energy distribution in the energy spectrum diagram. By setting a sliding window, calculate the local maximum value (energy peak) of the energy distribution within this window. The size of the sliding window can be set according to the measurement accuracy and signal noise level. For each marked energy peak, determine its corresponding peak energy point and count value. The energy point of the peak is the highest point in the energy distribution, and the peak count value is the radiation intensity corresponding to this point. At the same time, calculate the full width at half maximum (FWHM) of each energy peak. This value reflects the width of the peak. The integrated digital expression form is (peak energy point, peak radiation count value, full width at half maximum).

[0073] Record the digital expression of the characteristic energy distribution and the peak, and convert the digital expression into a structured storage format and upload it to the data management center.

[0074] In S3, perform binary hashing with similarity preservation on the digital expressions of the characteristic energy distribution and the peak to obtain the digital fingerprint corresponding to the radiation source, and write the digital fingerprint into the digital fingerprint field reserved in the RFID tag.

[0075] Obtain the digital expressions of the characteristic energy distribution and the peak corresponding to each radiation source in the data management center, and convert the obtained digital expression data into a string that does not contain any symbol information. This string should only contain numbers and their relative relationships. For example, use a specific delimiter (such as a comma, space, or unsigned fixed-length field) to combine the digital data in sequence into a pure digital sequence. For example, the digital expression of the characteristic energy distribution and the peak of a sample may be converted into the following string: [11, 12, 15, 17, 20].

[0076] Apply the binary hashing algorithm with similarity preservation (SimHash) to the pure digital strings obtained from each radiation source. SimHash is an efficient hashing algorithm that represents the input data by generating a binary hash value of a fixed length while preserving the similarity information between data as much as possible. For the digital expressions of different radiation sources, a binary hash value of a fixed length (such as 64 bits or 128 bits) can be obtained through SimHash. This serves as the unique identifier of the radiation source, ensuring that each radiation source has a unique digital fingerprint (the hash value has collision resistance in theory, making it almost impossible for similar data inputs to produce the same hash output). The following is a specific example:

[0077] Map each number in [11, 12, 15, 17, 20] to a simple binary feature vector through a custom hash function. The number 11 corresponds to the feature vector: [1, 0, 0, 1, -1], the number 12 corresponds to the feature vector: [1, 1, -1, 0, 1], the number 15 corresponds to the feature vector: [0, -1, 1, 1, 1], the number 17 corresponds to the feature vector: [-1, 1, 1, -1, 0], and the number 20 corresponds to the feature vector: [0, -1, -1, 1, -1];

[0078] Add the feature vectors of all numbers one by one specifically as: [1 + 1 + 0 - 1 + 0, 0 + 1 - 1 + 1 - 1, 0 - 1 + 1 + 1 - 1, 1 + 0 + 1 - 1 + 1, -1 + 1 + 1 + 0 - 1] = [1, 0, 0, 0, 0]. According to the weighted sum vector, generate the final vector by symbolization (i.e., taking the sign). Usually, if an element is greater than 0, the element is 1; if it is less than 0, the element is -1. In this way, the symbolized vector obtained is: [1, 0, 0, 0, 0], and then the final hash value is expressed as 10000.

[0079] Through the RFID programming device, write the generated digital fingerprint into the digital fingerprint field of the RFID tag. This field is used to store the digital fingerprints of each radiation source and will be used to verify the identity and status of the radiation source during subsequent detection and management processes.

[0080] Set an automatic update period according to the half-life of the radiation source for regularly updating the digital fingerprint in the RFID tag. This period can be determined based on the decay rate of the radiation source and the nuclide characteristics. Usually, radiation sources with shorter half-lives require more frequent updates of the digital fingerprint, while radiation sources with longer half-lives can have a relatively longer update period (since the half-lives are generally long, the update period can be set in years).

[0081] In S4, when the staff performs the removal operation, the reader reads the RFID tag data and uploads it through the opening and closing control of the storage cabinet door. Based on the uploaded data, the removed radiation source is screened out, and the status of the corresponding radiation source is modified to removed.

[0082] Install a staff identification system on the storage cabinet door, using technologies such as fingerprint recognition, face recognition, or card recognition to ensure that only authorized personnel can operate the access of the radiation source. This system should be networked with the control system of the storage cabinet to prevent unauthorized personnel from operating the cabinet door by verifying the employee's identity. The system automatically records the identity information and operation type of the staff while confirming the identity. The data should include the unique identifier of the staff, the operation type (deposit or removal), and the operation time and other information. This data will provide a basis for subsequent traceability.

[0083] The RFID reader is connected to the control element of the storage cabinet, and the control element is responsible for triggering the opening and closing operations of the cabinet door. This connection allows the reader to automatically start reading RFID tags when the cabinet door is opened and end reading when the cabinet door is closed, ensuring a complete reading record for each operation.

[0084] If the staff member selects the removal operation, the RFID tags on the radioactive source containers in the storage cabinet are scanned once each when the cabinet door is opened and closed to read the tag data, and the RFID tag data with the reading timestamp is uploaded and updated to the data management center.

[0085] The data management center compares the two pieces of data received, marks the status of the radioactive source in the RFID tags with missing second upload tag data as removed, and takes the timestamp of the cabinet door opening as the removal time of the radioactive source.

[0086] In S5, when the staff member performs the deposit operation, the characteristic energy distribution and peak data of the radioactive source to be deposited are detected, triggering digital fingerprint verification.

[0087] If the staff member selects the deposit operation, a lightweight energy spectrum detection instrument is used to detect the radioactive source to be deposited, obtain the characteristic energy distribution and peak data in the energy spectrum diagram of the radioactive source to be deposited, and convert the extracted characteristic energy distribution and energy peak data into digital form. Each energy point in the characteristic energy distribution and its corresponding count value (radiation intensity) are converted into discrete digital signals through an analog-to-digital converter (ADC). For the energy peak, the local maximum value is extracted through algorithms such as the sliding window method and stored digitally, including the peak energy, count value, and full width at half maximum (FWHM). The data is uploaded to the data management center, and digital fingerprint verification is triggered simultaneously.

[0088] In S6, digital fingerprint verification is performed on the radioactive source to be deposited, and the digital fingerprint recognition difference degree of the radioactive source to be deposited is calculated.

[0089] The data management center obtains the latest energy spectrum data of the radioactive source to be deposited, recalculates the digital fingerprint corresponding to the radioactive source to be deposited through the SimHash algorithm, and marks this fingerprint as the comparison fingerprint.

[0090] The data management center retrieves the corresponding digital fingerprint field through the unique identifier (UID) of the stored RFID tag. The data successfully retrieved through the UID includes the digital fingerprint stored in the RFID tag. This fingerprint represents the initial characteristics of the radiation source, which have been written into the storage area of the RFID tag during the initial registration of the radiation source. Using the method of calculating the Hamming distance, the comparison fingerprint stored in the data management center is compared with the digital fingerprint stored in the RFID tag. The Hamming distance is a measure of the dissimilarity between two strings. When calculating, it is necessary to compare two binary strings bit by bit and calculate the number of different bits. This value reflects the difference between the two digital fingerprints. The smaller the Hamming distance, the more similar the characteristics of the radiation source to be stored are to the existing source characteristics in the database, and the higher the probability of passing the fingerprint verification; conversely, when the Hamming distance is large, there may be a risk of source replacement or data error.

[0091] The difference degree of the digital fingerprint recognition of the radiation source to be stored is calculated by taking the ratio of the calculated Hamming distance to the total length of the digital fingerprint. This ratio can effectively reflect the difference degree between the two, and quantify the similarity of the source characteristics through the difference degree.

[0092] In S7, retrieve the change history record of the digital fingerprint of the radiation source to be stored, and set the dynamic digital fingerprint recognition difference degree threshold.

[0093] When determining the dynamic digital fingerprint recognition difference degree threshold, it is necessary to consider the usage time of the radiation source and the attenuation characteristics of the radiation intensity. Over time, the radiation intensity of the radiation source will decrease due to radioactive decay, which in turn affects its energy spectrum data and digital fingerprint. Radiation sources with faster attenuation may produce larger digital fingerprint differences, while radiation sources with slower attenuation may maintain smaller difference degrees. In the analysis of the same radiation source, the usage duration is one of the main factors affecting the attenuation of its radiation intensity.

[0094] Based on the unique identifier of the RFID tag corresponding to the radiation source to be stored, obtain all the digital fingerprint change records of this radiation source since its first storage from the data management center. The records should cover each removal and return of the radiation source, including the timestamp and the corresponding digital fingerprint data at each operation. Extract the time interval between each removal and return of the radiation source. These timestamp information are used to analyze the change trend of the digital fingerprint of the radiation source in different usage cycles.

[0095] The historical records are divided into multiple statistical groups according to the time interval between the removal and return of the radiation source. Each statistical group represents the usage of the radiation source within a specific time interval. For example, grouping can be done according to time periods such as short-term (e.g., 3 days), medium-term (e.g., 1 month), long-term (e.g., 1 year and above), etc. In each statistical group, records that pass the digital fingerprint verification are screened out, and the mean value of the digital fingerprint recognition difference degree of these records is calculated. The digital fingerprint recognition difference degree represents the similarity between the digital fingerprint of the radiation source to be deposited currently and the verified fingerprints in the historical records. These mean values reflect the stability of the digital fingerprint of the radiation source (i.e., the attenuation degree of the radiation intensity of the radiation source) and the variation law during the usage process within a specific time period.

[0096] Obtain the removal and return interval time of the radiation source to be deposited currently, perform a historical mean matching of the digital fingerprint recognition difference degree, set the acceptable range of recognition deviation (specifically set based on the similarity of the energy distribution of the stored radiation source, with the default setting being 3.13%, that is, outside the calculation of the mean value of the recognition difference degree, 1 bit error is allowed for every 32 bits), add the calculated mean value of the recognition difference degree to the set acceptable range of recognition deviation, and comprehensively determine the dynamic digital fingerprint recognition difference degree threshold of the radiation source to be deposited.

[0097] In S8, based on the digital fingerprint recognition difference degree of the radiation source to be deposited, determine whether the digital fingerprint passes the verification. If so, allow the radiation source to be deposited. If not, further determine whether the radiation source to be deposited is misplaced or source replaced, and modify the radiation source status according to the judgment result.

[0098] Based on the set dynamic digital fingerprint recognition difference degree threshold, if the recognition difference degree calculated during the digital fingerprint verification of the radiation source to be deposited is less than the recognition difference degree threshold, it is judged that the digital fingerprint verification passes. At this time, open the storage cabinet door to allow the radiation source to be deposited, mark the radiation source status as placed, and record the placement time simultaneously;

[0099] Update the comparison fingerprint during the recognition process as the new digital fingerprint into the digital fingerprint field in the RFID tag;

[0100] If the recognition difference degree calculated during the digital fingerprint verification of the radiation source to be deposited is greater than or equal to the recognition difference degree threshold, it is judged that the digital fingerprint verification fails, and the radiation source to be deposited is prohibited from being deposited into the storage cabinet.

[0101] Retrieve and extract the digital fingerprints with the radiation source status marked as removed from all RFID data in the data management center, and integrate them into a digital fingerprint group.

[0102] Calculate the recognition difference degree between the comparison fingerprint that fails the digital fingerprint verification and each digital fingerprint in the digital fingerprint group one by one. If there is a digital fingerprint with a recognition difference degree less than the set recognition difference degree threshold in the calculation result (indicating that there is a radioactive source that matches the digital fingerprint stored in the RFID of the container to be deposited at this time), then mark the status of the radioactive source corresponding to the compared and the compared digital fingerprints as misplacement error.

[0103] If there is no digital fingerprint with a recognition difference degree less than the set recognition difference degree threshold in the digital fingerprint group (indicating that there is no radioactive source that matches the digital fingerprint stored in the RFID of the container to be deposited at this time), then mark the status of the radioactive source to be deposited as suspected source replacement and send an alarm message.

[0104] The above formulas are all calculated by removing the dimension and taking their numerical values. The formula is a formula obtained by collecting a large amount of data for software simulation to get the closest to the real situation. The preset parameters and threshold selection in the formula are set by those skilled in the art according to the actual situation.

[0105] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or data center that contains one or more collections of available media. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0106] Those of ordinary skill in the art can realize that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0107] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated herein.

[0108] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of devices or modules can be in an electrical, mechanical, or other form.

[0109] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules. They can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0110] In addition, the functional modules in each embodiment of this application can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module.

[0111] If the above-mentioned functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0112] As described above, the above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

[0113] Finally: The above is only the preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for safe supervision of the use of exempted radioactive sources based on RFID, characterized in that: The steps include: S1: Put an RFID tag on each radioactive source container in the exempted radioactive source storage cabinet and write the initial data, and reserve a digital fingerprint field; S2: Detect the energy spectrum of each radiation source one by one, extract the characteristic energy distribution and peak value in the energy spectrum, convert the characteristic energy distribution and peak value into digital expression and upload them to the data management center; S3: performing binary hashing to preserve similarity on the digital expressions of characteristic energy distribution and peak value to obtain a digital fingerprint corresponding to the radiation source, and writing the digital fingerprint into a digital fingerprint field reserved in the RFID tag; S4: When the staff performs the removal operation, the RFID tag data is read and uploaded through the opening and closing control reader of the storage cabinet door, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to have been removed; S5: When the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the digital fingerprint verification is triggered; S6: verifying the digital fingerprint of the radioactive source to be stored, and calculating the difference degree of the digital fingerprint recognition of the radioactive source to be stored; S7: Retrieve the historical records of characteristic energy distribution attenuation after use of each radioactive source, and set a dynamic digital fingerprint recognition difference threshold; S8: judging whether the digital fingerprint is verified based on the difference of the digital fingerprint recognition of the radioactive source to be stored, if so, allowing the radioactive source to be stored, if not, further judging whether the radioactive source to be stored is misplaced or replaced by a source, and modifying the state of the radioactive source according to the judgment result; In S7, the digital fingerprint change history record of the radioactive source to be stored is retrieved, and the dynamic digital fingerprint recognition difference threshold is set, which specifically includes: Based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, the digital fingerprint change history of the radioactive source is retrieved in the data management center; The retrieved digital fingerprint change history records are grouped and counted according to the interval time between taking out and returning, and the average value of the digital fingerprint recognition difference of the digital fingerprint verification records in each statistical group is calculated; Obtain the interval time between the retrieval and return of the radioactive source to be stored, perform historical mean matching of the difference in digital fingerprint recognition, set an acceptable range of recognition deviation, and comprehensively determine the dynamic digital fingerprint recognition difference threshold of the radioactive source to be stored; In S8, based on the difference of the digital fingerprint recognition of the radioactive source to be stored, it is determined whether the digital fingerprint is verified. If so, the radioactive source to be stored is allowed to be stored. If not, it is further determined whether the radioactive source to be stored is misplaced or replaced by a source. Modifying the state of the radioactive source according to the determination result specifically includes: Based on the set dynamic digital fingerprint recognition difference threshold, if the recognition difference calculated in the digital fingerprint verification of the radioactive source to be stored is less than the recognition difference threshold, it is judged that the digital fingerprint verification has passed, and the storage cabinet door is opened to allow the radioactive source to be stored, and the state of the radioactive source is marked as placed, and the placement time is recorded; Update the compared fingerprint in the identification process as a new digital fingerprint into the digital fingerprint field in the RFID tag; If the identification difference of the radioactive source to be stored calculated in the digital fingerprint verification is greater than or equal to the identification difference threshold, it is judged that the digital fingerprint verification has not passed, and the radioactive source to be stored is prohibited from being stored in the storage cabinet; Retrieve and extract digital fingerprints of radioactive sources marked as removed from all RFID data in the data management center, and integrate them into a digital fingerprint group; Calculate the identification difference between the comparison fingerprint and the digital fingerprint group that failed the digital fingerprint verification. If the calculation result shows that there is a digital fingerprint with an identification difference less than a set identification difference threshold, mark the radioactive source state corresponding to the comparison and the compared digital fingerprint as a placement error. If there is no digital fingerprint in the digital fingerprint group whose identification difference is less than the set identification difference threshold, the state of the radioactive source to be stored is marked as a suspected source replacement, and an alarm message is sent.

2. According to claim 1, a method for safe supervision of the use of exempted radioactive sources based on RFID is characterized in that: In S1, an RFID tag is added to each radioactive source container in the exempted radioactive source storage cabinet and initial data is written. At the same time, a digital fingerprint field is reserved, including: Obtain all radioactive source containers in the exempted radioactive source storage cabinet, select active RFID tags with long-distance recognition capabilities, and adhere the RFID tags to the surface of the radioactive source containers; Assign a unique identifier to the RFID tag of each radioactive source container, and use an RFID programming device to write initial data into the tag storage area, the initial data including the type of radioactive source, activity value, and status of the radioactive source; A space is reserved in the RFID tag storage area for storing the digital fingerprint field of the radioactive source, and the initial value of the field is set to empty.

3. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 2, characterized in that: In S2, the energy spectrum of each radiation source is detected one by one, the characteristic energy distribution and peak value in the energy spectrum are extracted, and the characteristic energy distribution and peak value are converted into digital expressions and uploaded to the data management center. Specifically, it includes: Based on the type of exempted radioactive sources, a lightweight energy spectrum detection instrument with the required monitoring energy range is selected, and the energy spectrum detection instrument is calibrated using a standard energy source; Use the energy spectrum detection instrument to perform one-by-one detection on the radioactive sources in the exempted radioactive source storage cabinet, obtain the energy spectrum of each radioactive source, extract the characteristic energy distribution and peak value in the energy spectrum of the radioactive source and convert it into digital expression: The energy signal of the extracted characteristic energy distribution is quantized into a discrete digital signal through analog-to-digital conversion, and each energy point corresponds to a count value; The local maximum value of each up and down cycle in the characteristic energy distribution is extracted by the sliding window method and marked as the energy peak value, and the peak energy point and count value corresponding to the energy peak value, as well as the full width half maximum value, are obtained; The digital expression of characteristic energy distribution and peak value is recorded, and the digital expression is converted into a structured storage format and uploaded to the data management center.

4. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 3, characterized in that: In S3, the digital expressions of the characteristic energy distribution and the peak value are subjected to binary hash processing with similarity preservation to obtain the digital fingerprint corresponding to the radiation source, and the digital fingerprint is written into the digital fingerprint field reserved in the RFID tag. Specifically, it includes: The digital expression of characteristic energy distribution and peak value corresponding to each radiation source is obtained at the data management center, and the digital expression data is converted into a character string without any symbol information; The string is processed using a binary hash algorithm that retains similarity to obtain a unique digital fingerprint of a fixed length, which is then written into the digital fingerprint field in the RFID tag storage area using an RFID programming device.

5. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 4, characterized in that: In S4, when the staff performs the removal operation, the RFID tag data is read and uploaded through the storage cabinet door opening and closing control reader, the removed radioactive source is screened out based on the uploaded data, and the corresponding radioactive source status is modified to be removed, which specifically includes: Install a staff identification system on the door of the storage cabinet. After the staff has confirmed their identity, they can choose to deposit or withdraw. An RFID reader is provided in the radioactive source storage cabinet, and a control element connected to the door of the storage cabinet is built in; If the staff chooses to take out the radioactive source, the RFID tag on the radioactive source container in the storage cabinet is scanned once when the cabinet door is opened and closed to read the tag data, and the RFID tag data with the reading timestamp is uploaded and updated to the data management center; The data management center compares the two received data, marks the status of the radioactive source in the RFID tag with missing tag data in the second upload as removed, and uses the timestamp of the cabinet door opening as the removal time of the radioactive source.

6. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 5, characterized in that: In S5, when the staff performs the storage operation, the characteristic energy distribution and peak data of the radioactive source to be stored are detected, and the digital fingerprint verification is triggered, which specifically includes: If the staff chooses to store the radioactive source, a lightweight energy spectrum detection instrument will be used to detect the radioactive source to be stored, obtain the characteristic energy distribution and peak data in the energy spectrum of the radioactive source to be stored, upload the data to the data management center, and trigger digital fingerprint verification at the same time.

7. The RFID-based method for safe use supervision of exempted-level radioactive sources according to claim 6, characterized in that: In S6, the digital fingerprint verification is performed on the radioactive source to be stored, and the digital fingerprint identification difference of the radioactive source to be stored is calculated, which specifically includes: Recalculate the digital fingerprint corresponding to the radioactive source to be stored in the data management center, and mark the fingerprint as a comparison fingerprint; At the data management center, based on the unique identifier of the RFID tag corresponding to the radioactive source to be stored, the digital fingerprint stored in the corresponding digital fingerprint field is retrieved, and the Hamming distance between the digital fingerprint and the comparison fingerprint is calculated; The ratio of the Hamming distance to the digital fingerprint length is marked as the digital fingerprint identification difference of the radioactive source to be stored.

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