A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip'...A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip's cross section (crown) to express the shape control ability of rolling mill. With the mathematical models and simulation software that were developed by the authors' own models, four types of mills were aimed, including HCM (6-high middle rolls shift type HC (high crown) -mill), HCMW (6-high middle rolls and work rolls shift type HC-mill), UCM (6-high middle rolls shift type HC-mill with middle roll bender) and UCMW (6-high middle rolls and work rolls shift type HC-mill with middle roll bender), and the shape and crown control ability of every mill type was analyzed and compared. An appropriate arrangement mode of tandem mill was brought forward. The results show that UCMW mill is a perfect choice for controlling shape and crown, and the area of control characteristics curve of UCMW (or UCM) is twice than that of HCM, but UCM mill is also a good choice for its simple frame. In other word, the shape and crown controlling ability of UCMW mill is better than that of UCM mill, but the frame of UCM mill is simpler than that of UCMW mill. As for the final type of mill, should be synthetically decided by thinking over fund and equipment technology.展开更多
The mechanism type plays a decisive role in the mechanical performance of robotic manipulators. Feasible mechanism types can be obtained by applying appropriate type synthesis theory, but there is still a lack of effe...The mechanism type plays a decisive role in the mechanical performance of robotic manipulators. Feasible mechanism types can be obtained by applying appropriate type synthesis theory, but there is still a lack of effective and efficient methods for the optimum selection among different types of mechanism candidates. This paper presents a new strategy for the purpose of optimum mechanism type selection based on the modified particle swarm optimization method. The concept of sub-swarm is introduced to represent the different mechanisms generated by the type synthesis, and a competitive mechanism is employed between the sub-swarms to reassign their population size according to the relative performances of the mechanism candidates to implement the optimization. Combining with a modular modeling approach for fast calculation of the performance index of the potential candidates, the proposed method is applied to determine the optimum mechanism type among the potential candidates for the desired manipulator. The effectiveness and efficiency of the proposed method is demonstrated through a case study on the optimum selection of mechanism type of a heavy manipulator where six feasible candidates are considered with force capability as the specific performance index. The optimization result shows that the fitness of the optimum mechanism type for the considered heavy manipulator can be up to 0.578 5. This research provides the instruction in optimum selection of mechanism types for robotic manipulators.展开更多
Plant type and grain quality are two major aspects in rice breeding. Using canonical correlation analysis and canonical redundancy analysis, the relationship between plant type traits and rice grain quality traits was...Plant type and grain quality are two major aspects in rice breeding. Using canonical correlation analysis and canonical redundancy analysis, the relationship between plant type traits and rice grain quality traits was studied with 100 crosses derived from 10 sterile lines × 10 restorer lines. There was a complex relationship between parts of the traits of the two aspects. The angle of the 2nd leaf from the top and single panicle weight played important roles in plant type system and amylose content and grain length in grain quality system. The angle of the 2nd leaf from the top, plant height and single panicle weight had a great effect on grain quality traits, and amylose content, brown rice rate and translucency were easily influenced by plant type traits. Selection index model indicated that japonica hybrid rice in Northern China with good quality was characterized by broad flag leaf and 2nd leaf from the top, narrow and short 3rd leaf from the top, low plant height, short culm, long and more panicles and low single panicle weight.展开更多
Gate type selection is very important for mould design. Improper gate typemay lead to poor product quality and low production efficiency. Although numerical simulationapproach could be used to optimize gate location, ...Gate type selection is very important for mould design. Improper gate typemay lead to poor product quality and low production efficiency. Although numerical simulationapproach could be used to optimize gate location, the determination of gate type is still up todesigners' experience. A novel method for selecting gate type based on fuzzy logic is proposed. Theproposed methodology follows three steps: Design requirements for gate is extracted and generalized;Possible gate types (design schemes) are presented; The fuzzy mapping relationship between gatedesign requirements and gate design scheme is established based on fuzzy composition and fuzzyrelation transition matrices that are assigned by domain experts.展开更多
Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level ...Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level and the mechanism level of conceptual design.The principle of computer coding and storing have been built to give a fast and broad selection of mechanisms that meets the requirements of basic motion characters.Then on the basis of mentioned above,the heuristic matching propagation principle (HMPP) of kinematic behaviors and its true table serves as a guide to perform mechanism types selection.Finally an application is given to indicate its practicability and effectiveness.展开更多
Based on the practice of Baosteel＇ s 60000 m3/h air separation unit （ASU） ,which is the first domestically- integrated unit of such a scale, this paper studies the principles of type selection of the distribution c...Based on the practice of Baosteel＇ s 60000 m3/h air separation unit （ASU） ,which is the first domestically- integrated unit of such a scale, this paper studies the principles of type selection of the distribution control system （DCS）. It discusses the design of the unit＇s control system,which involves a compressor system,a purification system （molecular sieving）, a turbo expansion system and an air separation system. The final part of the paper discusses the maintenance and future development of the ASU control system at Baosteel.展开更多
The type selection of burning equipment for boilers is affected significantly by the slagging characteristics of coal. Based on the engineering statistics method, the designed furnace parameters are obtained from the ...The type selection of burning equipment for boilers is affected significantly by the slagging characteristics of coal. Based on the engineering statistics method, the designed furnace parameters are obtained from the 600-MW and 1 000-MW boilers with tangential firing and wall firing. The power and arrangement of the burners are analyzed. Their impacts on slagging on heating surfaces and the carbon contents in the ash and cinders are also discussed. Thermal parameters of furnace are recommended for boilers of 600 MW and 1 000 MW firing slagging coal in the design. The static or rotary classifier should be the first choice for the pulverizing system.展开更多
When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coa...When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coal and the technical measures are discussed for enhancing the combustion and burnout.The adaptability of tangential firing,wall firing and double-arch firing for low volatile coal is studied.Based on the statistic analysis for the main design parameters of domestic low volatile coal fired boilers with tangential firing,wall firing or double-arch W flame firing,the thermal performance for various boiler furnaces is recommended.The combustion systems for different types of boilers are also put forward for coals with different volatiles.展开更多
At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam construct...At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams.展开更多
With rapid development of nuclear power in China, in view of reactor type selection, this paper analyzes the current situation that faces nuclear power industry, the technical characteristics of optional reactors and ...With rapid development of nuclear power in China, in view of reactor type selection, this paper analyzes the current situation that faces nuclear power industry, the technical characteristics of optional reactors and the tendency of nuclear power technology development in the future. The proposals put forward in this paper include choosing and introducing GW-class advanced PWR as main reactors, carrying out self-supporting projects and technical transfer negotiations, in addition, promoting the design of the advanced generation-Ⅱ PWR and initiating small-scaled construction. The ultimate target is to catch up with the world advanced level by means of technical upgrading and recreation based on technology importation and assimilation.展开更多
Neurotrophic receptor kinase(NTRK) fusions are actionable oncogenic drivers of multiple pediatric and adult solid tumors,and tropomyosin receptor kinase(TRK) has been considered as an attractive therapeutic target for...Neurotrophic receptor kinase(NTRK) fusions are actionable oncogenic drivers of multiple pediatric and adult solid tumors,and tropomyosin receptor kinase(TRK) has been considered as an attractive therapeutic target for "pan-cancer" harboring these fusions.Currently,two generations TRK inhibitors have been developed.The representative second-generation inhibitors selitrectinib and repotrectinib were designed to overcome clinic acquired resistance of the first-generation inhibitors larotrectinib or entrectinib resulted from solvent-front and gatekeeper on-target mutations.However,xDFG(TRKAG667C/A/S,homologous TRKCG696C/A/S) and some double mutations still confer resistance to selitrectinib and repotrectinib,and overcoming these resistances represents a major unmet clinical need.In this review,we summarize the acquired resistance mechanism of the first-and second-generation TRK inhibitors,and firstly put forward the emerging selective type Ⅱ TRK inhibitors to overcome xDFG mutations mediated resistance.Additionally,we concluded our perspectives on new challenges and future directions in this field.展开更多
In order to research the capacity differences of road intersections,this paper analyzed the influence factors and calculation models of various types of capacity at intersections and then obtained simplified models th...In order to research the capacity differences of road intersections,this paper analyzed the influence factors and calculation models of various types of capacity at intersections and then obtained simplified models through reasonable assumption. 2 /2,4 /2,4 /4 intersections at which saturation and forecasted traffic volume were given were taken as examples,and an appropriate type was selected through capacity comparison. This paper can give a predictive estimation of the intersection capacity and provides theoretical data for the type selection of intersections.展开更多
In China,the abrasion index and the free moisture are regarded as the criteria for determining whether the medium-speed pulverizer or the fan pulverizer could be selected.Based on comprehensive studies on foreign meth...In China,the abrasion index and the free moisture are regarded as the criteria for determining whether the medium-speed pulverizer or the fan pulverizer could be selected.Based on comprehensive studies on foreign methods for choosing the pulverizing system for lignite boilers,it is suggested that the particle size of coal,the drying time,the drying temperature and the humidity should be taken into account when measuring the free moisture of lignite,and the total moisture could also be the principle for type selection of pulverizer for lignite boilers.Furthermore,the determination of pulverized-coal moisture has great influence on the running of pulverizing systems.The actual moisture of certain pulverized coals is compared with that calculated with different methods and a feasible method for determining the moisture of the pulverized coal is suggested.展开更多
In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurr...In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurrence of each working condition to be different. Under the conversion of different working conditions, this makes the vibration of different types of cutterheads different. How to choose the appropriate type of cutterhead according to different geological conditions is very important for saving engineering cost and increasing cutterhead life. In view of the above situation, this paper proposes a stability evaluation method during the TBM tunneling process to select the appropriate cutterhead type. Firstly, the corresponding relationship between geology and working conditions is established according to different geological conditions, and the input loads corresponding to geological conditions are obtained. Then, it is substituted into the dynamic model of the cutterhead system, the vibration response boundaries of each degree of freedom are obtained by solving. And the average value of the maximum boundary amplitude of each degree of freedom is taken to represent the extreme vibration of the cutterhead under the corresponding working conditions. Finally, by comparing the fluctuation of the ultimate vibration amplitude of each type of cutterhead in the process of working condition conversion, the results are as follows: when the transition between homogeneous strata and composite strata is normal and there is no large turning and deviation correction, the vibration response of the two-part cutterhead is the smallest, and the two-part cutterhead is the best choice. Otherwise, the five-part cutterhead is the best choice, while the stability of the integrated cutterhead is the worst.展开更多
By establishing some suitable partitions of input and output spaces, a novel fuzzy neural network (FNN) which is called selection type FNN is developed. Such a system is a multilayer feedforward neural network, which ...By establishing some suitable partitions of input and output spaces, a novel fuzzy neural network (FNN) which is called selection type FNN is developed. Such a system is a multilayer feedforward neural network, which can be a universal approximator with maximum norm. Based on a family of fuzzy inference rules that are of real senses, a simple and useful inference type FNN is constructed. As a result, the fusion of selection type FNN and inference type FNN results in a novel filter-FNN filter. It is simple in structure. And also it is convenient to design the learning algorithm for structural parameters. Further, FNN filter can efficiently suppress impulse noise superimposed on image and preserve fine image structure, simultaneously. Some examples are simulated to confirm the advantages of FNN filter over other filters, such as median filter and adaptive weighted fuzzy mean (AWFM) filter and so on, in suppression of noises and preservation of image structure.展开更多
基金Project (50374058) supported by the National Natural Science Foundation of China and Shanghai Baosteel Group Co.
文摘A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip's cross section (crown) to express the shape control ability of rolling mill. With the mathematical models and simulation software that were developed by the authors' own models, four types of mills were aimed, including HCM (6-high middle rolls shift type HC (high crown) -mill), HCMW (6-high middle rolls and work rolls shift type HC-mill), UCM (6-high middle rolls shift type HC-mill with middle roll bender) and UCMW (6-high middle rolls and work rolls shift type HC-mill with middle roll bender), and the shape and crown control ability of every mill type was analyzed and compared. An appropriate arrangement mode of tandem mill was brought forward. The results show that UCMW mill is a perfect choice for controlling shape and crown, and the area of control characteristics curve of UCMW (or UCM) is twice than that of HCM, but UCM mill is also a good choice for its simple frame. In other word, the shape and crown controlling ability of UCMW mill is better than that of UCM mill, but the frame of UCM mill is simpler than that of UCMW mill. As for the final type of mill, should be synthetically decided by thinking over fund and equipment technology.
基金supported by National Natural Science Foundation of China (Grant No. 51075259)Program for New Century Excellent Talents in University of Ministry of Education, China (Grant No. NCET-10-0579)+1 种基金National Basic Research Program of China (973 program, Grant No.2006CB705407)Key Technologies R&D Program of Shanghai,China (Grant No. 10111100203)
文摘The mechanism type plays a decisive role in the mechanical performance of robotic manipulators. Feasible mechanism types can be obtained by applying appropriate type synthesis theory, but there is still a lack of effective and efficient methods for the optimum selection among different types of mechanism candidates. This paper presents a new strategy for the purpose of optimum mechanism type selection based on the modified particle swarm optimization method. The concept of sub-swarm is introduced to represent the different mechanisms generated by the type synthesis, and a competitive mechanism is employed between the sub-swarms to reassign their population size according to the relative performances of the mechanism candidates to implement the optimization. Combining with a modular modeling approach for fast calculation of the performance index of the potential candidates, the proposed method is applied to determine the optimum mechanism type among the potential candidates for the desired manipulator. The effectiveness and efficiency of the proposed method is demonstrated through a case study on the optimum selection of mechanism type of a heavy manipulator where six feasible candidates are considered with force capability as the specific performance index. The optimization result shows that the fitness of the optimum mechanism type for the considered heavy manipulator can be up to 0.578 5. This research provides the instruction in optimum selection of mechanism types for robotic manipulators.
文摘Plant type and grain quality are two major aspects in rice breeding. Using canonical correlation analysis and canonical redundancy analysis, the relationship between plant type traits and rice grain quality traits was studied with 100 crosses derived from 10 sterile lines × 10 restorer lines. There was a complex relationship between parts of the traits of the two aspects. The angle of the 2nd leaf from the top and single panicle weight played important roles in plant type system and amylose content and grain length in grain quality system. The angle of the 2nd leaf from the top, plant height and single panicle weight had a great effect on grain quality traits, and amylose content, brown rice rate and translucency were easily influenced by plant type traits. Selection index model indicated that japonica hybrid rice in Northern China with good quality was characterized by broad flag leaf and 2nd leaf from the top, narrow and short 3rd leaf from the top, low plant height, short culm, long and more panicles and low single panicle weight.
文摘Gate type selection is very important for mould design. Improper gate typemay lead to poor product quality and low production efficiency. Although numerical simulationapproach could be used to optimize gate location, the determination of gate type is still up todesigners' experience. A novel method for selecting gate type based on fuzzy logic is proposed. Theproposed methodology follows three steps: Design requirements for gate is extracted and generalized;Possible gate types (design schemes) are presented; The fuzzy mapping relationship between gatedesign requirements and gate design scheme is established based on fuzzy composition and fuzzyrelation transition matrices that are assigned by domain experts.
基金Sponsored by the Chinese National Foundation of Science Na 59875058.
文摘Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level and the mechanism level of conceptual design.The principle of computer coding and storing have been built to give a fast and broad selection of mechanisms that meets the requirements of basic motion characters.Then on the basis of mentioned above,the heuristic matching propagation principle (HMPP) of kinematic behaviors and its true table serves as a guide to perform mechanism types selection.Finally an application is given to indicate its practicability and effectiveness.
文摘Based on the practice of Baosteel＇ s 60000 m3/h air separation unit （ASU） ,which is the first domestically- integrated unit of such a scale, this paper studies the principles of type selection of the distribution control system （DCS）. It discusses the design of the unit＇s control system,which involves a compressor system,a purification system （molecular sieving）, a turbo expansion system and an air separation system. The final part of the paper discusses the maintenance and future development of the ASU control system at Baosteel.
文摘The type selection of burning equipment for boilers is affected significantly by the slagging characteristics of coal. Based on the engineering statistics method, the designed furnace parameters are obtained from the 600-MW and 1 000-MW boilers with tangential firing and wall firing. The power and arrangement of the burners are analyzed. Their impacts on slagging on heating surfaces and the carbon contents in the ash and cinders are also discussed. Thermal parameters of furnace are recommended for boilers of 600 MW and 1 000 MW firing slagging coal in the design. The static or rotary classifier should be the first choice for the pulverizing system.
文摘When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for low volatile coal and the technical measures are discussed for enhancing the combustion and burnout.The adaptability of tangential firing,wall firing and double-arch firing for low volatile coal is studied.Based on the statistic analysis for the main design parameters of domestic low volatile coal fired boilers with tangential firing,wall firing or double-arch W flame firing,the thermal performance for various boiler furnaces is recommended.The combustion systems for different types of boilers are also put forward for coals with different volatiles.
文摘At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams.
文摘With rapid development of nuclear power in China, in view of reactor type selection, this paper analyzes the current situation that faces nuclear power industry, the technical characteristics of optional reactors and the tendency of nuclear power technology development in the future. The proposals put forward in this paper include choosing and introducing GW-class advanced PWR as main reactors, carrying out self-supporting projects and technical transfer negotiations, in addition, promoting the design of the advanced generation-Ⅱ PWR and initiating small-scaled construction. The ultimate target is to catch up with the world advanced level by means of technical upgrading and recreation based on technology importation and assimilation.
基金financial support from the National Natural Science Foundation of China (82273763)the Natural Science Foundation of Guangdong Province (2022A-1515011939, China)+2 种基金the Opening Project of State Key Laboratory of Respiratory Disease (SKLRD-OP-202313, China)the Opening Project of Guangdong Provincial Key Laboratory of New Drug Design and Evaluation (2020B1212060034, China)Wang Kuancheng Young Scholar of Jinan University
文摘Neurotrophic receptor kinase(NTRK) fusions are actionable oncogenic drivers of multiple pediatric and adult solid tumors,and tropomyosin receptor kinase(TRK) has been considered as an attractive therapeutic target for "pan-cancer" harboring these fusions.Currently,two generations TRK inhibitors have been developed.The representative second-generation inhibitors selitrectinib and repotrectinib were designed to overcome clinic acquired resistance of the first-generation inhibitors larotrectinib or entrectinib resulted from solvent-front and gatekeeper on-target mutations.However,xDFG(TRKAG667C/A/S,homologous TRKCG696C/A/S) and some double mutations still confer resistance to selitrectinib and repotrectinib,and overcoming these resistances represents a major unmet clinical need.In this review,we summarize the acquired resistance mechanism of the first-and second-generation TRK inhibitors,and firstly put forward the emerging selective type Ⅱ TRK inhibitors to overcome xDFG mutations mediated resistance.Additionally,we concluded our perspectives on new challenges and future directions in this field.
基金Sponsored by the Natural Science Foundation of Heilongjiang Province ( Grant No. E2007-14)
文摘In order to research the capacity differences of road intersections,this paper analyzed the influence factors and calculation models of various types of capacity at intersections and then obtained simplified models through reasonable assumption. 2 /2,4 /2,4 /4 intersections at which saturation and forecasted traffic volume were given were taken as examples,and an appropriate type was selected through capacity comparison. This paper can give a predictive estimation of the intersection capacity and provides theoretical data for the type selection of intersections.
文摘In China,the abrasion index and the free moisture are regarded as the criteria for determining whether the medium-speed pulverizer or the fan pulverizer could be selected.Based on comprehensive studies on foreign methods for choosing the pulverizing system for lignite boilers,it is suggested that the particle size of coal,the drying time,the drying temperature and the humidity should be taken into account when measuring the free moisture of lignite,and the total moisture could also be the principle for type selection of pulverizer for lignite boilers.Furthermore,the determination of pulverized-coal moisture has great influence on the running of pulverizing systems.The actual moisture of certain pulverized coals is compared with that calculated with different methods and a feasible method for determining the moisture of the pulverized coal is suggested.
基金National Natural Science Foundation of China(Grant No. 51875076) NSFC-Liaoning United Key fund (Grant No. U1708255).
文摘In the process of tunneling of tunnel boring machine (TBM), different geological conditions often correspond to different working conditions, and the randomness of geological conditions also causes the order of occurrence of each working condition to be different. Under the conversion of different working conditions, this makes the vibration of different types of cutterheads different. How to choose the appropriate type of cutterhead according to different geological conditions is very important for saving engineering cost and increasing cutterhead life. In view of the above situation, this paper proposes a stability evaluation method during the TBM tunneling process to select the appropriate cutterhead type. Firstly, the corresponding relationship between geology and working conditions is established according to different geological conditions, and the input loads corresponding to geological conditions are obtained. Then, it is substituted into the dynamic model of the cutterhead system, the vibration response boundaries of each degree of freedom are obtained by solving. And the average value of the maximum boundary amplitude of each degree of freedom is taken to represent the extreme vibration of the cutterhead under the corresponding working conditions. Finally, by comparing the fluctuation of the ultimate vibration amplitude of each type of cutterhead in the process of working condition conversion, the results are as follows: when the transition between homogeneous strata and composite strata is normal and there is no large turning and deviation correction, the vibration response of the two-part cutterhead is the smallest, and the two-part cutterhead is the best choice. Otherwise, the five-part cutterhead is the best choice, while the stability of the integrated cutterhead is the worst.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 69974006, 69974041, 60174013).
文摘By establishing some suitable partitions of input and output spaces, a novel fuzzy neural network (FNN) which is called selection type FNN is developed. Such a system is a multilayer feedforward neural network, which can be a universal approximator with maximum norm. Based on a family of fuzzy inference rules that are of real senses, a simple and useful inference type FNN is constructed. As a result, the fusion of selection type FNN and inference type FNN results in a novel filter-FNN filter. It is simple in structure. And also it is convenient to design the learning algorithm for structural parameters. Further, FNN filter can efficiently suppress impulse noise superimposed on image and preserve fine image structure, simultaneously. Some examples are simulated to confirm the advantages of FNN filter over other filters, such as median filter and adaptive weighted fuzzy mean (AWFM) filter and so on, in suppression of noises and preservation of image structure.
