257 results about "Medium term" patented technology

A system and method for providing backstop liquidity for an extendable commercial paper issue used to finance asset-backed securitization transactions through an up-front commitment from a highly rated entity to purchase fixed-income securities. A conduit that issues extendable commercial paper backed by a plurality of asset securitization transactions obtains a triple-A rated guaranty for each of the plurality of asset-backed securitization transactions and secures an up-front commitment from a highly rated backstop provider to purchase fixed-income securities to be issued in the future by such conduit (or an affiliated conduit) to retire such conduit's outstanding extendable commercial paper in the event that the conduit is unable to retire such commercial paper before the end of its extension period. The extendable commercial paper includes secured liquidity notes (SLNs) and the fixed-income securities include asset-backed medium-term notes (MTNs).

The invention discloses a medium-term and long-term combined power generation optimal scheduling method and a medium-term and long-term combined power generation optimal scheduling system in a cascade reservoir group. The method comprises the following steps that: S1, a scheduling server establishes and stores three medium-term and long-term optimal scheduling models, namely a model of largest cascade power generation capacity, a model of largest cascade power generation capacity which gives consideration to guaranteed output, and a model of largest cascade energy storage; S2, the scheduling server selects an optimal medium-term and long-term optimal scheduling model according to a power generation optimal objective; S3, a data acquisition device acquires materials required for solving the models, and the scheduling server solves the medium-term and long-term optimal scheduling models by selecting algorithms; and S4, the scheduling server generates and outputs a medium-term and long-term power generation scheduling optimal scheme. By the method and the system, the phenomenon that a large quantity of optimization variables and constraint conditions of cascade reservoir optimal scheduling influence computational efficiency and result reasonability can be avoided; and an optimal medium-term and long-term combined power generation optimal scheduling scheme is obtained.

The invention discloses a low-salt liquid state fermented soy sauce production process, comprising the following main processes: preparing koji in a koji-maker machine; mixing the wheat which is fried and smashed with koji, inoculating the mixture in soybean meal and bran which are cooked; preparing finished koji in a koji making disc machine; mixing the finished koji with brine, sending the mixture in a fermenting vat for fermentation; preparing the finished soy sauce through soaking, pouring oil, filtrating, mixing, sterilizing and filling to obtain the finished soy sauce. The soy sauce is characterized in that materials containing zygosaccharomyces Rouxii 2.180 accounting for 1.5-2.5% of the total weight of materials and torulopsis candida 2.202 accounting for 1.5-2.5% of the total weight of materials are added during the medium term of the fermentation process and the raw materials--soybean meal and bran are cooked by high temperature short-time continuous cooking process. Compared with the prior art, the raw material digestion rate can reach 88-90%, the protein utilization rate can reach 83%, the activity of neutral protease of the finished koji can reach 2000mu / g, the enzymesystem is complete, the defects such as long period of high-salt liquid state fermentation (180 days), burnt flavour and heavy bitter taste of low-salt solid state fermentation and the like are overcame and the produced soy sauce is characterized by strong soysauce-like aroma, alcohol-like aroma and ester-like aroma and the like.

The invention discloses a real-time prediction method of mine gas concentration in short and medium terms based on radial basis function neural network integration. The method comprises the following steps of: taking mine gas concentration data as a chaotic time series to construct a plurality of prediction sub-models of radial basis function (RBF) neural networks, and taking a weighted mean of synchronous prediction results of all prediction sub-models as an integrated prediction value to realize prediction model initializtion of RBF neural network integration; then realizing prediction of the gas concentration in the range of from a short term to a medium term through setting an integrated capacity parameter (the integrated capacity parameter is also equal to an RBF network prediction step-length); and obtaining a new prediction sub-model by utilizing an incremental training mode aiming at the characteristics that gas concentration information is continuously collected, and realizing updating of the RBF neural network integration according to a first in first out queue sequence so as to improve real-time prediction precision of the gas concentration, therefore, a proper compromise can be obtained between prediction range and prediction precision requirements, and the technical requirement on a mine gas information management system is satisfied.

The invention discloses a method for forecasting the silicon content in blast-furnace hot metal, which comprises the steps of data parameter selection, pre-processing, prediction algorithm, result output and operation guidance. In the step of data parameter selection, five parameters such as short-term mean value of the silicon content, medium-term mean value of the silicon content, long-term mean value of the silicon content, tuyere theoretical combustion temperature corresponding to the previous hot metal and sulfur content in the previous hot metal are adopted, and the silicon content is predicted through the prediction algorithm. When the furnace condition fluctuation is small, an average line system is mainly used; and when the furnace condition fluctuation is large, the tuyere theoretical combustion temperature and the sulfur content in the previous hot metal are automatically added. In the invention, less data parameters are adopted, better forecasting precision is obtained andthe forecasting correctness of the silicon content in the blast-furnace hot metal is improved.

The invention discloses an oiled paper insulation power equipment insulation aging state detecting method. The method includes a first step of carrying out the preparatory work, enabling oiled paper insulation power equipment to be disconnected with a line, enabling insulation terminals to be detected to be connected in a pup joint mode through copper bare wires and connected to the ground to discharge, a second step of wiring according to introductions of an instrument, a third step of setting parameters, a fourth step of finishing a detection, and obtaining a time domain feature parameter t through spectrum unfolding, a fifth step of bringing the time domain feature parameter t and oiled paper insulation temperature T to a designated formula, and calculating and judging the insulating aging state of oiled paper, that is, a degree of polymerization (DP) value, and a sixth step of confirming that the overall insulation of the oiled paper insulation power equipment is in a medium term of the service life when the average DP of the oiled paper decreases to 500, confirming expiration of service life of the oiled paper insulation power equipment when the average DP decreases to 250, and confirming that the mechanical strength of insulation paper is almost zero when the DP decreases to 150. The oiled paper insulation power equipment insulation aging state detecting method does no hang a core, does not damage insulation materials, does not carry out sampling, can accurately estimate the average DP value of the insulation paper, and judges the oiled paper insulation aging state.

Mechanical, electronic, algorithmic, and computer network facets are combined to create a highly integrated advanced sensor that monitors the gas density, state-of-repair, and events associated with switchgear. Measurements of gas pressure, atmospheric pressure, gas temperature, are used with models of the non-ideal behavior of a particular gas to realistically estimate gas density. A hierarchical system of signal processing optimizes measurements working within high-frequency, real-time, short-term, medium-term, diurnal, long-term, and historical timeframes and overcomes measurement errors present in real-world applications. The time at which a condition such as gas density will reach a particular level is calculated. Events such as threshold attainments and switchgear operation are detected. A large memory stores all raw data values allowing flexible re-processing and verification at any future time. Instantaneous as well as logged information is communicated in convenient formats over a selected digital network. An embedded web server provides a familiar graphical user interface.

The invention discloses a method for autonomously and continuously planning satellite tasks. The method comprises the steps: enabling a satellite to calculate executable tasks entering into a set G at a certain moment according to a satellite track and a target control region set G; enabling the tasks to be divided into a long-term task, a medium-term task and a short-term task through a hierarchical planning method; and judging whether the tasks can be set into a new task set P' or not according to a current state set S of the satellite. If there is resource conflict in the execution of a plurality of tasks, the conflict removal is carried to according to a preset rule. A current task set P is updated and remains consistent with the new task set P', and the short-term tasks, which arrive at the starting time, in the current task set P are extracted and sent to a real-time system for execution. Finally, a set G and a set S are updated. The method achieves that the satellite accurately senses the state and an external environment and is controlled to autonomously complete various types of task without depending on external control and information injection, improves the autonomous working capability of the satellite, and reduces the risk that a critical fault happens to the satellite.

The invention relates to a batch-to-batch optimization method of a batch process by combining a medium-term correction strategy. The method comprises the following steps: firstly establishing a quality variable predictive model of an NLPLS, and carrying out prediction on final product quality according to control operation variables of the process; on the basis of the model, calculating an optimal control strategy and implementing the optimal control strategy on a practical device; adopting a recurrence algorithm to carry out updating on the original NLPLS model according the newly-obtained data and old model parameters after each batch is finished; then solving the optimal control strategy again and implementing the optimal control strategy on an object; generally, after several batches, leading the control strategy to converge a satisfactory solution; and simultaneously, in order to process the interference in batches, adopting the medium-term correction strategy, utilizing new information obtained by the current batch to carry out correction on the latter control strategy. The method combines the batch-to-batch optimization and the medium-term correction strategy, makes up the insufficiency that the traditional batch-to-batch optimization method can not process the interference in batches and improves the control performance.

The invention discloses a fresh water shrimp culture method, which comprises the steps of weed culture, shrimp postlarvae selection, stocking time selection, and control during shrimp postlarvae culture. The step of control during the shrimp postlarvae culture comprises the steps of: controlling waterweed coverage rate and water body transparency: when the fresh water shrimp culture is in the medium term, particularly fresh water shrimps enter autumn-propagation season (August and September in Yangtze river basin), the waterweed area is controlled to be 40 to 50 percent of the water body area, the transparency is controlled to more than 40 centimeters, and shrimp postlarvae is difficult to survive due to insufficient plankton bait; and killing the autumn-propagation shrimp postlarvae by skillfully using quick lime: during culture, the growth and development condition of the shrimps is frequently observed, particularly when the fresh water shrimps enter the autumn-propagation season (August and September in Yangtze river basin), the egg hatching condition of precocious female is observed, and when eggs of most ovigerous female become grey or transparent or zoea is hatched out, 10 to 14g of quick lime is used for each cubic meter of water body, the quick lime is sprayed to all the pond in six days, and afterwards the quick lime is used once each week to kill the autumn-propagation shrimp postlarvae. The technical measure can reduce 70 to 90 percent of autumn-propagation shrimp postlarvae.

The invention encompasses a mobile, expandable shelter intended to provide medium term housing to disaster victims. The invention minimizes moving parts so as to make the shelter more structurally sound and allows full deployment by two people in less than ten minutes without the use of a motor to supply hydraulic, pneumatic or electric assistance. This shelter will maximize space by offering the unique feature of side shells that slide over the base structure not out of the base structure.

Video surveillance systems are used in a multitude of applications in order to monitor large areas. Such video surveillance systems customarily include a plurality of fixed-mounted cameras that record relevant surveillance scenes and a central surveillance station in which the video sequences of the cameras are brought together. Often, the evaluation of the assembled video data is performed by surveillance personnel. As is known, the surveillance activities of surveillance personnel are very fatiguing, which is why possibility that important events in the surveillance scenes may be overlooked cannot be ruled out. For this reason, it has long been common practice to use known image-processing algorithms for automated evaluation of video sequences. An image-processing device is proposed for carrying out an object segmentation in which the object segmentation is executed and / or is executable through comparison of a camera image to a scene reference image of a surveillance scene, equipped with a learning device for generating the scene reference image; the learning device is embodied to generate the scene reference image through evaluation of a medium-term and / or long-term observation of the surveillance scenea) that extends over a time period of longer than one day, preferably longer than several days, in particular longer than 1 week, and / orb) that extends over a time period that includes several states of the surveillance scene.

A static-dynamic automatic feeding method in the converter smelting process belongs to the technical field of automatic control. In the converter smelting process, according to various factors such as components of loaded molten iron, added scrap steel amount and remaining slag amount and by calculation of a secondary steel grade model, a static feeding information sheet is generated and issued to a primary programmable logic controller (PLC) control procedure. The primary PLC control procedure receives material information of the feeding information sheet, prepares materials for secondary material information according to the technological requirements and the principle that an identical material is equally distributed in an identical bin, performs material transfer in real time and automatically carries out converter feeding according to smelting oxygen-blowing amount. After sublance converting medium-term measurement is finished, molten steel components are measured. According to comparing difference between measurement components and target components, the secondary steel grade model undergoes calculation again to generate a dynamic feeding information sheet, the dynamic feeding information sheet is issued to the primary PLC control procedure, and material preparation and feeding are automatically carried out. The static-dynamic automatic feeding method has the advantages of effectively solving the problems that manual feeding is not timely, unstable and inaccurate and the like, improves working efficiency and smelting hit rate, reduces feeding cost, shortens smelting cycle, effectively reduces labor and guarantees continuous and stable high-level automatic production.

The invention discloses an anti-collision radar device of a navigation mark, which comprises a lamp, a global positioning system (GPS) positioning meter and an electrical strain monitoring device. The anti-collision radar device of the navigation mark is characterized by further comprising a radar detection device, a camera, a radar signal processor and a wireless data transceiving device. Radar signals sent back by the radar signal processor is judged and processed by control of a single chip microcomputer; when a ship is at a primary early-warning distance, a primary early warning is carried out; when the ship is at a medium-term warning distance, the camera is started to begin to take photos of a dangerous ship and obtain evidences, and early warning is carried out once again simultaneously; and when the radar detection device detects the fact that a collision distance between the ship and the navigation mark is reached, the camera continuously takes photos of the dangerous ship until the dangerous ship is far away from a warning area. The anti-collision radar device has the advantages that the size of installed equipment is small, and the influence on the structural shape and floating conditions of the navigation mark is small. Besides, the anti-collision radar device is installed on the basis of an original navigation mark, is convenient and concise, saves fund, and is suitable for wide popularization in the field of the navigation marks.

The invention discloses Chinese medicinal liquor and particularly discloses Chinese medicinal liquor for treating rheumatic and rheumatoid arthritis and a preparation method thereof. The Chinese medicinal liquor for treating the rheumatic and rheumatoid arthritis is characterized by being prepared from the following components: Chinese angelica, Szechuan lovage rhizome, cassia twig, dahurian angelicaroot, incised notopterygium rhizome, divaricate saposhnikovia root, root of largeleaf gentian, clematis root, processed common monkshood mother root, processed kusnezoff monkshood root, papaya, medicinal cyathula root, tall gastrodia tuber, liquor garter snake, coix seed, safflower, fried peach seed, himalayan teasel root, turmeric, yellowmouth dutchmanspipe root, processed atraotydin, vinegar armadillo and earthworm. The Chinese medicinal liquor is specially used for treating the rheumatic and rheumatoid arthritis, has clinical application safety, treats both principal and secondary aspects of diseases, does not stimulate internal organs after being orally taken, has quick response, is safe and reliable, can make a patient have early recovery, medium-term control and late relief, and has the better effects of treating the rheumatic and rheumatoid arthritis and neck-waist-limb pain or relieving the symptoms. The Chinese medicinal liquor totally treats 580 patients, and the total effective rate reaches 97 percent.

The invention discloses an apple preservation method and belongs to the field of fruit and vegetable preservation. According to the method, apples are preserved and stored through the steps of pre-harvest treatment, post-harvest treatment, soaking treatment and storage in a fresh-keeping storehouse. Through adoption of the method, the apple quality can be effectively kept, and the apple storage period can be prolonged; the method is practical and flexible, and thus can be adopted for short-term, medium-term and long-term storage; apples which are subjected to post-harvest treatment but not subjected to follow-up treatment can be preserved and stored in a short term; apples which are subjected to soaking treatment and storage in a fresh-keeping storehouse can be preserved and stored in a medium and long term; apples which are subjected to soaking treatment, modified atmosphere packaging and storage in a fresh-keeping storehouse can be preserved and stored in a long term.

The invention discloses an electric corn medium-term fertilizer distributor which comprises a main frame and an electric motor rack, wherein a fertilizer can is installed on the main frame, the left side and the right side of the lower part of the fertilizer can are respectively provided with a fertilizer apparatus, hoppers and fertilizer pipes are respectively arranged below the discharge ports of the fertilizer apparatuses, and the lower ends of the fertilizer pipes are respectively connected with a furrow opener; the main frame is fixedly connected with the electric motor rack at the front end through pins, a storage battery, an electrical motor and a controller are fixedly installed at the front end of the electric motor rack, and handles are fixedly installed on the side plates at the two ends of the electric motor rack; chain wheels which are installed on a transmission gear are connected with the mounting shafts of the fertilizer apparatuses which are arranged below the fertilizer can through a chain and a clutch, and the two ends of the mounting shafts of the fertilizer apparatuses are respectively provided with a fertilizer amount regulation flange which is connected with the fertilizer apparatuses; and driving wheels and the mounting shafts of the fertilizer apparatuses are driven by the electric motor to operate, and the electric motor is supplied with power by the storage battery. The electric corn medium-term fertilizer distributor is reasonable and reliable in structural design, utilizes the electric motor to provide power, has no pollution, is low in noise, and ensures the fertilizing depth and fertilizing amount of the corn growth medium-term fertilizing.

The invention discloses an oil reservoir division and comparison method based on high resolution sequence stratigraphy. The oil reservoir division and comparison method comprises the steps of: identifying medium-term base level cycles based on rock cores, drilling / logging seismic data, high resolution sequence stratigraphy, base level cycles and an admissible space change principle, by means of the change trend of an A / S value; dividing and comparing oil groups by interfaces and flooding surfaces of the identified medium-term base level cycles; based on the drilling / logging seismic data, the flooding surface and conversion surface of the change of a reference surface, identifying short-term base level cycles, and dividing and comparing sand groups; according to the identified superposed modes of short-term base level cycles, establishing an isochronous stratigraphic framework by means of comparison; and according to the stratigraphic framework, controlling division and comparison small layers under the control of the cycle and stratum superposed modes. The oil groups, the sand groups and the small layers are included in an oil reservoir division and comparison unit. According to the invention, the oil reservoir division and comparison method solves the problem in the prior art that a diachronous phenomenon usually occurs in the comparison process.

Provided is a medium-term regional power load prediction method based on a data clustering theory. The method includes region partition, influence factor correlation analysis and load space distribution prediction. By utilizing a clustering theory method and adopting a region block as a basic unit, each region block within a district is repartitioned and combined according to the similarity to serve as a basic unit for later load prediction. By utilizing a neural network algorithm to predict the load density and the synchronous rate, the time, space and other multi-attribute multilayer factorsare taken into account, the influence factors of different layers on the load density and the synchronous rate are mined, the precision and efficiency of the load prediction method can be improved, and refined planning of a power grid is facilitated. Meanwhile, a BP neural network algorithm is suitable for load prediction and has the advantages that calculation is stable, the classification capability in an arbitrary complicated pattern is excellent, and the multi-dimensional function mapping capability is great.

The invention provides a medium-short term coordinated dispatching method for ultra-high voltage AC-DC hybrid power grid, and relates to the field of electrical power system power generation dispatching. When electricity is transmitted from west to east, feed-in scale is sharply increased in a low peak period, and load adjustment difficulty of a receiving power network is significantly increased, causing a power grid medium-short term start-up mode and running plan arrangement difficulty to be increased accordingly. The method comprises medium term plan formulation and short term plan formulation. The medium term plan formulation adopts a month as a decision cycle and a day as a calculation period, on the conditions of guaranteeing electrical power system load requirements and operational parameters of a power station and a machine set, monthly electricity is divided into days, and a daily start-up mode of the machine set is optimized; the short term plant forms a 96-point power output plan of daily electricity according to a short-term load prediction result; rolling amendment is conducted on an original medium-term power generating plan according to the latest prediction information of the load and machine set actual electricity completion situation; according to the technical scheme, frequent start-ups and stops of the power generating machine set are avoided, effective engagement and mutual coordination between a medium term and short term power generating plan are achieved.

The invention relates to a hydraulic and hydroelectric engineering construction diversion risk analysis technology and aims at overcoming the shortcomings of a traditional high rock-fill dam medium-term food season water retaining risk rate detection technology, providing a novel high rock-fill dam medium-term food season water retaining risk rate detection method, accurately and reasonably quantifying the medium-term food season water retaining risk rate and providing important basis for food season security risk assessment, construction schedule formulation and the like. The uncertainty of flood prevention food season elevation is considered in the method, and a high rock-fill dam project medium-term food season water retaining risk rate mathematical model is established. The uncertainties of shutdown day number and the daily average rising speed each month are considered, and a simulating calculation model of a dam body flood preventing flood season elevation is established. The randomness of the daily average rising speed each month is subjected to quantitative analysis. The randomness of hydroelectric, hydraulic and filling construction is comprehensively considered, and the water retaining risk calculation process is provided by coupling risk elements based on a Monte-Carlo method principle. The high rock-fill dam medium-term food season water retaining risk rate detection method is suitable for high rock-fill dam medium-term food season water retaining risk rate assessment.

The invention discloses a real-time load regulating method for a power grid using a hydro-thermal power working condition self-matching mode. The real-time load regulating method includes that calculating the difference delta P between the real-time released load of the power grid and the planning load of the previous day, confirming a hydro-thermal power load regulating principle according to the current scheduling period of a cascade hydropower station, under the constraints of a water level running control range established at the medium-term scheduling and a thermal power output bandwidth, regulating the hydro-thermal power output in real time according to the hydro-thermal power load regulating principle, delta P and the final water level of each time period of the hydropower station, making a hydro-thermal power output plan, and under the constraints of running water level, discharged volume and time period water level / flow rate change amplitude, optimally distributing load between cascade hydropower stations according to the traditional maximum energy storage target according to the hydro-thermal power output plan. The real-time load regulating method for the power grid using the hydro-thermal power working condition self-matching mode meets the working condition requirements of different periods of the cascade hydropower station and is capable of giving consideration to the stability and economical efficiency of the power grid.

The invention discloses an electric power system static security assessment method considering wind speed correlation. According to wind speed historical data, cut-off pair copula is used to realize wind speed modeling with non-linear correlation; then according to fan power characteristics, electric power system quick static security assessment is realized. The electric power system static security assessment method can be used for processing wind speeds with any probability characteristics in an electric power system and is suitable for quickly assessing the influence of connected wind power plants on the static security of the electric power system in medium-term and long-term plans.

The invention relates to a soybean sauce brewing method capable of avoiding preservative in soybean sauce production. The brewing method comprises the following steps: cooking: cooking soaked soybeans to obtain cooked soybeans; mixing: mixing the cooked soybeans with flour mixture according to a weight ratio of 1: (0.1 to 0.2), thus obtaining a mixed material; inoculating: inoculating the mixed material with aspergillus oryzae; making starter: culturing the mixed material after the inoculation into starter; fermenting: mixing the starter and saline water according to a weight ratio of 1: (1.6 to 2.5), ensuring the salt content of soy sauce mash before the fermentation to be 14.0 to 15.5 g / 100mL, adding flour yeast and table salt into the soy sauce mash in 60 to 80 days of the fermentation, and adjusting the weight ratio of the cooked soybeans and the flour mixture to be 1: (0.8 to 1.2) and the content of the water yellow salt to be 17.0 to 19.0 g / 100mL. By reducing the addition amount of flour when in starter making, the intake of sugar-type nutritional substances by salt-resistant microorganisms is reduced; and meanwhile, the soy sauce mash is produced by adopting low-concentration saline water, so that the growth and propagation of salt-resistant microorganisms can be inhibited. A manner of adding the flour yeast and table salt is adopted in the medium term of the fermentation, so that the flavor of the raw soy sauce is supplemented.

The invention relates to a combined device for synchronous denitrification and methanogenesis as well as autotrophic nitrogen removal of landfill leachate and a method thereof. The device is provided with an integrated water tank, a synchronous denitrification and methanogenesis reactor, an A / O shortcut nitrification reactor, a settling tank, and an anaerobic ammoxidation reactor. A mixed solution of stock leachate and an effluent reflux liquid of the anaerobic ammoxidation reactor firstly flows into the synchronous denitrification and methanogenesis reactor, the effluent of which then flows into the A / O reactor for shortcut nitrification and denitrification, and the effluent of the settling tank flows into the anaerobic ammoxidation reactor. The outlet pipe of the synchronous denitrification and methanogenesis reactor is connected to the anaerobic ammoxidation reactor. The method consists of the steps of: starting the synchronous denitrification and methanogenesis reactor, starting the A / O shortcut nitrification reactor, starting the anaerobic ammoxidation reactor, and bringing the three reactors into series operation. The device of the invention is suitable for removal of COD (chemical oxygen demand) and nitrogen from early and medium term landfill leachate of landfills, and has obvious advantages of energy saving and consumption reducing.

The invention provides a quick seedling cultivation method for paris polyphylla. The quick seedling cultivation method comprises the following steps: selecting and preparing land, constructing an arched shed, making ridge, collecting and producing seeds, sowing the seeds, covering the ridge surface with a thin layer of dried pine needles, performing a series of medium-term managements, and the like. A seedling cultivation technology program is simple and very easy to execute; moreover, the cost is very low and resources are greatly saved. By utilizing the quick seedling cultivation method, the root growth speed and the seedling emergence speed of the paris polyphylla are high, 80% of the seeds grow roots 30 days after being sowed and emerge seedlings on March in the second year, and the knowledge that the seeds of the paris polyphylla emerge the seedlings in the third year only is broken thoroughly. The quick seedling cultivation method is very outstanding in effect and worthy of all-round popularization.

Approaches to the construction of indexes are addressed wherein a portfolio of securities such as stocks, bonds, or the like and their associated investment weights or shares is generated. Indexes can be used as investment tools in various ways. For instance, indexes comprising a plurality of securities can often be bought and sold more cheaply than buying and selling the individual constituents of the index. This pricing differential allows investment with reduced transaction costs. Alternatively, in passive and enhanced indexing, investments are made with reference to an index. Performance statistics such as return and risk are reported with respect to the reference index. Factor indexes can serve as active manager benchmarks or the underlyers for investable products such as exchange traded funds and mutual funds. Computer based systems, methods and software are addressed for constructing indexes that replicate the returns of a quantitative factor such as medium term momentum or value. Further, processes and methodology are described by which the index can have the best possible replication of the underlying factor returns as well as other desirable characteristics. The methodology provides an approach to determine the index even when all desirable characteristics of the index are not simultaneously achievable.