50results about How to "Improve the efficiency of withdrawal" patented technology

The invention belongs to the field of mechanical parking devices and discloses a planar moving type modularized intelligent stereo garage. A pre-parking device is arranged under a planar moving type parking platform and provided with a pre-parking module, a conveying direction of the pre-parking module is uniform with that of a lifting conveying mechanism of a lifting device, and the pre-parking module is in linkage with the lifting conveying mechanism. An intelligent vehicle parking and taking appointment making function is realized by the pre-parking device, a vehicle owner can park a vehicle on the pre-parking module to waist for automatic parking and can also make an appointment of vehicle taking, the to-be-taken vehicle is pre-transferred to the pre-parking module from the intelligentstereo garage, and accordingly vehicle parking and taking efficiency is remarkably improved while the intelligent vehicle parking and taking appointment making function is realized. In addition, whenfire accidents of vehicles occur, a traveling mechanism at the bottom of a parking platform module drives the parking platform module to move on rails to quickly transfer vehicles on fire and isolatethe vehicles on fire from nearby vehicles, so that other vehicles can be protected from being jeopardized, and high loss caused by situation escalation is effectively prevented.

The invention provides a bank self-service terminal recommendation method and device, and the method comprises the steps: receiving a withdrawal request sent by a user through a target bank self-service terminal, and the withdrawal request carrying a withdrawal amount and the target identification information of the target bank self-service terminal; obtaining a target remaining amount corresponding to the target identification information, and determining whether the withdrawal amount is greater than the target remaining amount; acquiring target position information corresponding to the target identification information under the condition of determining that the withdrawal amount is greater than the target remaining amount; determining a first recommended bank self-service terminal meeting a first preset condition according to the target position information and the withdrawal amount; and sending the information of the first recommended bank self-service terminal to the user. According to the scheme, a user can go to other self-service terminals to finish withdrawal under the condition of withdrawal failure, so that the withdrawal time of the user is reduced, the withdrawal efficiency is improved, and the user experience is improved.

The invention discloses a road upper layer intelligent automatic storage and retrieval parking system and a control method thereof, and belongs to the field of mechanical parking devices. The parkingsystem comprises a parking device and a control system. About the parking structure, a planar moving structure is used for the storage and retrieval of a vehicle, and through the combination of the translation and lifting movements of a vehicle loading plate, the vehicle can move and be switched according to a planned parking route on the parking platform, and by using two rows of parking spaces and one row of intermediate transition parking spaces, the transfer and parking of the vehicle can be achieved, the structure is simpler and more stable, and planning the storage and retrieval route iseasy, and the intelligent control is facilitated, moreover, the space utilization rate is higher, the storage and retrieval of the vehicle is safe and reliable, and the storage and retrieval efficiency is higher; about the control, the measurement information is detected by using vehicle sensors, and the movement of the vehicle is controlled by a programmable logic controller achieve the storageand retrieval of the vehicle, so that the automatic storage and retrieval of the vehicle is achieved, the control is simpler and more convenient, the actions for the storage and retrieval of the vehicle are coordinated and stable, and the work is more efficient.

The invention discloses a cover retracement method of dense steel wire ropes of a coal face, and is suitable for the retracement operation of the coal face. When the coal face is propelled to approach a stop line, a coal cutter is stopped after cutting from head to tail, and only cuts off a roof; anchor rods are mounted in drifts at the two sides of the coal face beforehand; plastic steel nets are laid between top beams of hydraulic brackets and the roof before steel wire ropes are put in; the laying is performed bracket by bracket from top to bottom; and the two ends of the steel wire ropes are respectively fixed on the anchor rods by clamps. The hydraulic brackets forwards move along with the propelling of the coal face; the plastic steel nets are continuously laid to the stop line; and the dense steel wire ropes and the plastic steel nets form a barrier to stop the emission of gangues in a gob, so that the labor intensity of workers is reduced, and the retracement efficiency of the coal face is improved; the steel wire ropes are applied to simplify the anchor rod support of the roof and to protect the plastic steel nets from being damaged by large gangues; the main sources of the steel wire ropes are underground waste steel wire ropes to achieve the secondary utilization; the normal stoping is not influenced by the laying procedure; and the method has the advantages of easy construction, simple method, low cost and high safety.

The invention discloses a traditional Chinese medicine microecological preparation and a preparation method thereof. The traditional Chinese medicine microecological preparation is prepared by adopting traditional Chinese medicine ultra-fine powder as the main ingredient of fermentation culture media, adopting bacillus coagulans as the producing strain and adopting the fermentation technology. The traditional Chinese medicine ultra-fine powder comprises the composition of 20-60 parts of milkvetch roots, 20-40 parts of glossy privet fruits and 20-40 parts of epimedium herb with the grain size of 1-60 micrometers. The preparation method comprises the steps of strain separation and purification, inclined face activation, seed solution preparation, fermentation and culture, ingredient extraction, granulation forming and the like. The traditional Chinese medicine microecological preparation and the preparation method thereof have the advantages that the medicine effect is good, the extraction rate is high, and the medicinal material utilization rate is high.

The invention discloses a book gripping device applied to an intelligent book shelf and a book picking and returning method of the book gripping device and belongs to the field of intelligent book shelves. The book gripping device disclosed by the invention comprises a frame and a book gripping claw mechanism; a frame transverse moving mechanism is arranged at the bottom of the frame; and the bookgripping claw mechanism is installed on a horizontal and longitudinal driving mechanism by virtue of a gripping claw reversing mechanism. The overall book gripping device disclosed by the invention can move transversely; the book gripping claw mechanism in the book gripping device can do independent transverse movement, lift movement and 90-degree overturn motion; meanwhile the book gripping clawmechanism comprises a bottom book push mechanism and a side book push mechanism, wherein the bottom book push mechanism can be used for horizontally pushing out a book; the side book push mechanism can be used for vertically pushing out the book, so that stable gripping or returning of the book in a vertical book shelf is realized; stability of a book conveying process is guaranteed; and the bookgripping device is simple and compact in structural design, realizes stable and reliable gripping of the book, improves the efficiency and reliability of picking and returning of the book, and effectively solves the problems about automatic borrowing and returning of the books in an intelligent book management system.

The invention provides a deposit and withdrawal device and financial self-service equipment, and belongs to the technical field of financial equipment. The deposit and withdrawal device comprises an upper frame, a banknote inlet-outlet port, a banknote taking module, a banknote storage module, a switching mechanism, a banknote fetching channel, a banknote detector and a banknote box, the banknoteinlet-outlet port is formed in the upper frame, the switching mechanism is connected with the banknote storage module and the banknote taking module and used for switching positions of the banknote storage module and the banknote taking module, so that a banknote inlet of the banknote storage module corresponds to the banknote inlet-outlet port, or a banknote outlet of the banknote taking module corresponds to the banknote inlet-outlet port, the banknote fetching channel corresponds to the banknote inlet of the banknote storage module or the banknote outlet of the banknote taking module, the banknote detector and the banknote box are communicated with the banknote fetching channel, and the banknote detector is further communicated with the banknote box. A customer can perform deposit or withdrawal without extending hands in deposit or withdrawal, the deposit and withdrawal device and the financial self-service equipment are convenient to use and stronger in adaptability, and deposit and withdrawal efficiency can be improved.

The invention relates to the technical field of web information processing, and provides an account withdrawal method and apparatus, a terminal device and a computer storage medium. The account withdrawal method comprises the steps of obtaining a voice instruction input by a user after login of a target account; identifying the voice instruction to obtain operation information, wherein the operation information comprises a withdrawal amount; according to the operation information, creating a withdrawal task; when the withdrawal task is executed, querying a maximum withdrawal amount, on that day, of the target account; if the maximum withdrawal amount, on that day, of the target account is greater than or equal to the withdrawal amount, finishing withdrawal operation through the target account. By adopting the account withdrawal method and apparatus, the withdrawal operation process of the user can be greatly simplified, so that the account withdrawal efficiency is improved.

The embodiment of the invention discloses a retracement method for a fan section of a fully-mechanized coal mining retracement working face. The retracement method comprises the steps that a supporting support is mounted in the fan section, wherein the supporting support supports a fan section top plate; a first hydraulic support to be retraced is drawn out; after the first hydraulic support to beretracted is drawn out, the supporting support moves in the direction close to a second hydraulic support to be retraced by rubbing the top plate; when the supporting support moves in the direction close to the second hydraulic support to be retraced by rubbing the top plate for a first preset distance, the supporting height of the supporting support is increased; when the supporting height of the supporting support is increased to first preset height, the second hydraulic support to be retraced is drawn out. According to the retracement method, the retracement efficiency can be improved, andthe retracement cost can be reduced.

The invention discloses an annular automatic car storing and picking parking system on an upper layer of a road and a control method thereof, and belongs to the field of mechanical parking devices. The annular automatic car storing and picking parking system on the upper layer of the road comprises a parking device and a control system, according to a parking structure, a plane moving type structure is utilized for car parking and picking, a car bearing board is translated and lifted for cooperation so that a car can move and change positions on a parking platform according to a planned annular route, the structure is simpler and more stable and can be intelligently controlled, the space utilization rate is high, and car parking and picking is safe and reliable; in a control aspect, a carsensor is utilized for detecting measuring information, a PLC controller is utilized for controlling the motion of the car to park or pick up the car, automatic car parking and picking is achieved, the control is simpler and more convenient, the car parking and picking motions are coordinate and stable, and the work is more efficient.

The invention belongs to the field of guns, and particularly relates to a double-layer cylinder flow arranging type small-bore gun muzzle brake and a manufacturing method thereof. The brake is of an integrated central symmetry structure and comprises an outer layer sleeve and an inner layer cylinder, the rear of the inner layer cylinder is the bottom end, the front portion of the inner layer cylinder is a cylinder body, the inner diameter of the cylinder body of the inner layer cylinder is larger than the inner diameter of the bottom end, multiple sets of kidney-shaped side holes are formed inthe cylinder body of the inner layer cylinder, the periphery of the inner layer cylinder is sleeved with the outer layer sleeve, the outer layer sleeve sequentially comprises a sleeve body, a front end face and a center bullet hole, the inner diameter of the front end face is reduced, the inner diameter of the center bullet hole is fixed and smaller than the inner diameter of the sleeve body of the outer layer sleeve, multiple sets of outer layer round holes are formed in the sleeve body of the outer layer sleeve, the sleeve body of the outer layer sleeve and the cylinder body of the inner layer cylinder are overlapped, and the inner side of the sleeve body of the outer layer sleeve and the outer side of the cylinder body of the inner layer cylinder are connected through a rib plate. Thewhole structure is formed and manufactured through the 3D printing technology. The double-layer porous structure is adopted for achieving the flow arranging effect of dispersion and dredging of gunpowder gas, and the gun muzzle low-impact wave danger benefits can be achieved.

The invention discloses a double-row and double-deck stereo mechanical parking device and a vehicle parking and picking-up method thereof, belonging to the field of mechanical parking devices. A double-deck parking device of the stereo mechanical parking device has a first-floor parking area and a second-floor parking area. Both the first-floor parking area and the second-floor parking area have two rows of parking spaces arranged side by side. A lifting bearing mechanism of a lifting parking and picking-up device has a top conveying mechanism and a bottom conveying mechanism. By setting the upper and lower transverse conveying mechanisms on the lifting parking and picking-up device, two rows of parking spaces can be designed in the upper parking area of the double-deck parking device, thenumber of parked vehicles is increased, and the space utilization rate is higher. The upper transverse conveying mechanism of the lifting parking and picking-up device is used as a temporary parkingspace in the process of vehicle pickup, so that the interference to vehicle parking and picking-up is avoided, vehicle parking and picking-up is more flexible and convenient, and the efficiency of vehicle parking and picking-up is improved. A conveying and carrying mechanism is used to transfer vehicles, the structure is simple, the operation is stable, and vehicle parking and picking-up is saferand more reliable.

The invention discloses an efficient muzzle brake which comprises a main body part. A round projectile flight channel is formed in the center, the bottom end of the projectile flight channel is connected to a body pipe in a threaded manner, and 2-10 gunpowder gas channels are symmetrically formed in two sides of the projectile flight channel. The diameters of two ends of the projectile flight channel are greater than or equal to the diameter of the middle section. Each of the gunpowder gas channels is composed of a gas chamber section and a guide section. The centers of the gunpowder gas channels on the same side are in the same plane. The width of the single gunpowder gas channel in the axial direction of the muzzle brake is smaller than the pore diameter of the body pipe, the length of the single gunpowder gas channel in the radial direction of the muzzle brake is not greater than the pore diameter of the body pipe, and the length of the single gunpowder gas channel is not greater than twice of the pore diameter of the body pipe. The angle formed between the guide section and the front end of the muzzle brake is ranged from 100 degrees to 150 degrees. The efficient muzzle brake disclosed by the invention integrates the advantages of an impact muzzle brake and a counteractive muzzle brake, so that the brake efficiency is improved, and side effects such as impact waves and infrasonic waves are reduced.

The invention relates to a single stand column double-layer lifting parking platform. The single stand column double-layer lifting parking platform comprises a base, a stand column, a lifting mechanism and a supporting platform. The lifting mechanism is arranged in the stand column, the supporting platform is installed on the lifting mechanism, a rotating mechanism, a translation mechanism and a translation track, the stand column is installed on the rotating mechanism, the rotating mechanism is installed on the translation mechanism, and the translation mechanism is slidably installed on thetranslation track. When an upper vehicle is picked up, a vehicle parked in the lower part does not require to be driven out first and then the upper vehicle is lowered and removed, two vehicles can beplaced in one parking space, and the parking and picking efficiency is improved.

The invention discloses a road upper intelligent automatic access parking device, and belongs to the field of mechanical parking devices. The access parking device is characterized in that two rows ofparallel fixing parking spaces which can carry vehicles through vehicle carrying plates are arranged on a parking platform assembly; a row of intermediate transition parking spaces are arranged between the two rows of fixing parking spaces; transferring of the vehicle carrying plates with the vehicles on the parking spaces can be realized through horizontal conveying mechanisms, transferring conveying mechanisms and translation conveying mechanisms capable of lifting; the planar moving structure is used to park and pick the vehicles; the vehicles can move and exchange positions according to aplanned annular path on the parking platform through translation and lifting of the vehicle carrying plates; transferring of the vehicles can be realized through cooperation between the two rows of parking spaces and a row of intermediate transition parking spaces; and the structure is simple and stable, intelligent control is facilitated, the space utilization rate is high, vehicle parking and picking is safe and reliable, and the parking and picking efficiency is high.

The invention relates to a suspended-type circular stereo parking garage. The suspended-type circular stereo parking garage comprises two annular tracks, transmission systems and a plurality of parking spaces. The two annular tracks are horizontally arranged on the same plane and are spaced at the distance of more than one parking space. Each annular track is internally provided with a plurality of sets of idler wheels, and the multiple parking spaces are hung on the idler wheels through ropes and divided into the upper layer and the lower layer. The transmission systems are arranged on the inner sides of the annular tracks, and the transmission systems drive the idler wheels to move, so that horizontal moving of the parking spaces is achieved. Rope winders are connected to the ropes for hanging the parking spaces. By adjusting the length of the ropes, rising and falling of the parking spaces are achieved, the structure is simple, parking and picking-up are convenient, and the suspended-type circular stereo parking garage is conveniently transformed in an existing parking place.

The invention discloses a road upper annular automatic access parking device, and belongs to the field of mechanical parking devices. The road upper annular automatic access parking device is characterized in that annular parking spaces are successively arranged on a parking platform assembly of a rectangular structure; horizontal and longitudinal conveying mechanisms for driving vehicle carryingplates for carrying vehicles to translate are arranged on the parking spaces; reversing motion of the vehicle carrying plates can be achieved by using the conveying mechanism which can lift to performreversing; the planar moving structure is used to park and pick the vehicles; the vehicles can move and exchange positions according to a planned annular path on the parking platform through translation and lifting of the vehicle carrying plates; the structure is simple and stable, intelligent control is facilitated, the space utilization rate is high, vehicle parking and picking is safe and reliable, and the parking and picking efficiency is high; and the parking device can be easily mounted above the road, will not affect lower traffic, and is especially suitable for construction in slow lanes and residential areas.

The invention discloses a working face supporting and withdrawing robot and a working method thereof. The working face supporting and withdrawing robot comprises a chassis, walking mechanisms, stand column withdrawing mechanisms and a cross beam withdrawing mechanism, wherein the stand column withdrawing mechanisms and the cross beam withdrawing mechanism both adopt a multi-degree-of-freedom mechanical arms, and all stages of mechanical arms are used in cooperation; a grabbing task is completed; the cross beam withdrawing mechanism cooperates with the work of the stand column withdrawing mechanisms, lifts the cross beam and ensures the stability of the cross beam in the withdrawing process of a single hydraulic prop by the stand column withdrawing mechanisms; each stand column withdrawing mechanism is provided with an unloading unit for unloading of the single hydraulic prop; a first camera shooting unit and a second camera shooting unit are used for collecting actual image data of operation objects corresponding to a first clamping hand and a second clamping hand, mechanization and automation of the working face support withdrawing process are achieved, the fully mechanized working face support withdrawing work efficiency is improved, the labor intensity of workers is greatly reduced, and potential safety hazards of underground operation workers are reduced.

The invention relates to an automatic paper money and coin distribution method and system, which aim to solve the problem that existing cash self-service equipment cannot process paper money, coins and a whole roll of coins at the same time. The method comprises the following steps of obtaining the actual delivery quantity and the withdrawal balance of each face value of paper money, coins and whole roll of coins in paper money equipment, coin equipment and whole roll equipment, sequentially performing division operation on a to-be-delivered amount or a residual to-be-delivered amount and each face value, rounding and judging to obtain the final delivery quantity of each face value; and the final delivery quantity of each face value is sent to control interfaces of paper money equipment, coin equipment and whole roll equipment, so that the equipment dispenses corresponding quantities of paper money, coins and whole roll of coins. According to the method, three kinds of equipment can be controlled at the same time for cash distribution and cash output, various withdrawal requirements of users are met, and the withdrawal efficiency is effectively improved.

The invention relates to the technical field of intelligent buses, and provides a multi-cabinet-door intelligent key cabinet and an intelligent key taking and returning system. The multi-cabinet-door intelligent key cabinet comprises a main cabinet unit and at least one auxiliary cabinet expansion unit; the main cabinet unit comprises a main cabinet body, a man-machine interaction panel, a card reader and a plurality of key storage positions; the plurality of key storage positions are arranged on the front surface of the main cabinet body; the man-machine interaction panel is embedded in the front surface of the main cabinet body; the card reader and a loudspeaker are arranged on the man-machine interaction panel; the auxiliary cabinet expansion unit comprises an auxiliary cabinet body and a plurality of key storage positions, wherein the plurality of key storage positions are arranged on the front face of the auxiliary cabinet body; the auxiliary cabinet expansion unit is electrically connected with the main cabinet unit; a central control board and a main cabinet main control board are arranged in the main cabinet body; the key storage positions are provided with electric control door plates; an auxiliary cabinet main control board is arranged in the auxiliary cabinet body. With the multi-cabinet-door intelligent key cabinet and the intelligent key taking and returning system of the invention adopted, a driver can conveniently take and return keys by himself, and the key taking and returning efficiency and the bus dispatching efficiency of a bus station are improved.

The invention discloses a stay wire binding wire manufacturing device which comprises a fixing base. A winding roller and a limiting roller which are arranged side by side are arranged on the fixing base, a gear A and a gear B are arranged on the winding roller and the limiting roller respectively and mesh with each other, and a limiting assembly is arranged on the limiting roller. The limiting assembly can move relative to the limiting roller, the free end of the limiting assembly can be in contact with the winding roller or the free end of the limiting assembly can be close to the winding roller, and a driving shaft is arranged at one end of the winding roller or one end of the limiting roller and can be connected with a power mechanism and driven by a power mechanism to drive the winding roller and the limiting roller to rotate. By means of the device, a binding wire can be rapidly wound, and wound binding wire rings are uniform in size, round and smooth.

The invention discloses roadway stacking mechanical parking equipment. The roadway stacking mechanical parking equipment comprises a stacker, a multi-layer roadway stacking garage, a vehicle fetchingauxiliary frame, a vehicle carrying plate and a carrier. The stacker is provided with a station, a lifting platform is correspondingly arranged on the station, and the carrier, the vehicle fetching auxiliary frame arranged on the carrier, and the vehicle carrying plate put on the vehicle fetching auxiliary frame are sequentially arranged on the lifting platform. The vehicle fetching auxiliary frame is slidingly connected with the carrier. The multi-layer roadway stacking garage is arranged beside the stacker and used for storing a vehicle, during vehicle storage, the carrier enables towing plates to rise through multiple towing devices on the vehicle fetching auxiliary frame to hook the vehicle carrying plate to convey a vehicle into the multi-layer roadway stacking garage, and when the vehicle is taken out, the towing plates rise to hook the vehicle carrying plate to haul back the vehicle carrying plate when the vehicle fetching auxiliary frame reaches the position below the vehicle carrying plate. Convenience is brought to parking of people, intelligent control is facilitated, the space utilization rate is higher, vehicle parking is safe and reliable, and the parking efficiency is higher.

The invention discloses a double-conversion double-row multi-layer three-dimensional parking device and a vehicle parking and picking method thereof, and belongs to the field of mechanical parking devices. The multi-layer three-dimensional parking device of the present invention has a multi-layer parking device with two or more layers of parking areas; each layer of floor parking area has two rowsof parking spaces arranged side by side, and each row of parking spaces have at least two independent parking spaces. A lifting parking and picking device has a first lifting bearing mechanism and asecond lifting bearing mechanism which are capable of horizontal and lifting movement; left and right lateral conveying mechanisms are disposed on the lifting parking and picking device; one lateral conveying mechanism is used for picking the vehicle, and the other lateral conveying mechanism is used as a temporary parking space during the vehicle pick-up process; two rows of parking spaces can bedisposed on an upper parking area of the multi-layer parking device, the parking number is increased, and the space utilization rate is high; interference between parking and picking can be effectively avoided, vehicle parking and picking is more flexible and convenient, and the parking and picking efficiency of the vehicle is improved; and the reliability is improved.

The invention discloses a distributed three-dimensional parking garage based on the Internet of Things, and relates to the technical field of parking garages. The problem that vehicle parking and taking operation is tedious is solved. The garage specifically comprises a center console, a garage body and a vehicle conveying mechanism. The garage body comprises a base, stand columns fixed to the four corners of the base, a top cover fixed to the top ends of the stand columns and partition plates fixed to one side faces of the stand columns at equal intervals. The inner walls of one sides of the base and the partition plate are rotationally connected with anti-skid conveying belts, the inner walls of the bottoms of the base and the partition plate are fixedly connected with second motors, and the output ends of the second motors are connected with the input ends of the anti-skid conveying belts opposite in position through connecting shafts. A guide ladder plate is arranged on the inner wall of one side of the base; the vehicle conveying mechanism comprises a movable supporting table, a hydraulic elevator fixed to the top face of the movable supporting table and a top base fixed to the top end of the hydraulic elevator. Vehicle parking and taking operation is easy, and the structure is stable.

The invention provides a top plate reinforced protection method for a fully mechanized coal mining face equipment withdrawing channel, which comprises the following steps: fixing a plurality of steel wire ropes at the bottom of a whole fiber net along the long edge direction, rolling up and dragging to a working face, fixing the end parts of the fiber net and the steel wire ropes on a top plate, and positioning the rest parts on a hydraulic support; a rope coiling device and a pulley are fixed on the hydraulic support, a steel strand passes through the pulley, and a containing cavity is formed at the pulley and the top plate and used for containing a fiber net and a steel wire rope which are not spread; the fiber net and the steel wire ropes are laid along with pushing of the hydraulic support, all the rope coiling devices are tightened at intervals, and the steel wire ropes on the two sides of the laid fiber net are tensioned and fixed to a top plate through anchor cables; and the hydraulic support is pushed to be close to a mining stopping line of the retracement roadway, the front end of the hydraulic support extends the remaining fiber net and the steel wire rope to the top plate and the side of the retracement channel, and the fiber net and the steel wire rope in the channel area are fixed. The labor intensity of workers is reduced, and the supporting efficiency is improved.

The embodiment of the invention discloses a retracement method for a fan section of a fully-mechanized coal mining retracement working face. The retracement method comprises the steps that a supporting support is mounted in the fan section, wherein the supporting support supports a fan section top plate; a first hydraulic support to be retraced is drawn out; after the first hydraulic support to beretracted is drawn out, the supporting support moves in the direction close to a second hydraulic support to be retraced by rubbing the top plate; when the supporting support moves in the direction close to the second hydraulic support to be retraced by rubbing the top plate for a first preset distance, the supporting height of the supporting support is increased; when the supporting height of the supporting support is increased to first preset height, the second hydraulic support to be retraced is drawn out. According to the retracement method, the retracement efficiency can be improved, andthe retracement cost can be reduced.