The research reviewed standardized production technology of virus-free seed potato, including stem tip isolation, tissue culture seedling production, breeder's seed and protospecies production, and standard potato tu...The research reviewed standardized production technology of virus-free seed potato, including stem tip isolation, tissue culture seedling production, breeder's seed and protospecies production, and standard potato tubers' production, and concluded a set of standardized production technology for virus-free seed potato, in order to provide theoretical references for improving potato yield.展开更多
Northeast China has experienced frequent droughts over the past fifteen years. However, the effects of droughts on net primary productivity(NPP) in Northeast China remain unclear. In this paper, the droughts that occu...Northeast China has experienced frequent droughts over the past fifteen years. However, the effects of droughts on net primary productivity(NPP) in Northeast China remain unclear. In this paper, the droughts that occurred in Northeast China between 1999 and 2013 were identified using the Standardized Precipitation Evapotranspiration Index(SPEI). The NPP standardized anomaly index(NPP-SAI) was used to evaluate NPP anomalies. The years of 1999, 2000, 2001, and 2007 were further investigated in order to explore the influence of droughts on NPP at different time scales(3, 6, and 12 months). Based on the NPP-SAI of normal areas, we found droughts overall decreased NPP by 112.06 Tg C between 1999 and 2013. Lower temperatures at the beginning of the growing season could cause declines in NPP by shortening the length of the growing season. Mild drought or short-term drought with higher temperatures might increase NPP, and weak intensity droughts intensified the lag effects of droughts on NPP.展开更多
The paper analyzes the characteristics of rice production in Heilongjiang Reclamation Area(HRA)and the achievements made through innovative research and practice,evaluates the standardized mode of rice cultivation and...The paper analyzes the characteristics of rice production in Heilongjiang Reclamation Area(HRA)and the achievements made through innovative research and practice,evaluates the standardized mode of rice cultivation and technical standards for rice production,which play a key role in guaranteeing the growth of grain total output in Heilongjiang reclamation area and make great contributions to the national grain safety.展开更多
Numerous studies evaluated the effects of end-of-pipe control environmental regulations(EER).However,few scholars discussed the effects of process management environmental regulations(PER),such as the China Cleaner Pr...Numerous studies evaluated the effects of end-of-pipe control environmental regulations(EER).However,few scholars discussed the effects of process management environmental regulations(PER),such as the China Cleaner Production Standards(CCPS)implemented by the country's Ministry of Ecology and Environment.Using data on China's manufacturing enterprises,this paper adopts the CCPS policies as quasi-natural experiments and uses differences-in-differences(DID)methods to analyze their effects on enterprise profitability and profit quality,respectively.The results show that:first,the CCPS significantly improve both profitability and profit quality;that is,the implementation of the environmental regulation policy plays a significant role in improving enterprise profit rates and cash flows.Second,for the profitability mediator effects,the short-term Porter effect of CCPS is not significant but shows the opposite during the lag period and significantly reduces the management cost and wage levels,comprehensively promoting enterprise profitability.Third,for the profit quality meditator effects,environmental regulations improve the enterprises'cash flow by reducing management costs and increasing government subsidies;however,its effect on bank credit subsidies is not significant.Fourth,for the moderator effects,the environmental regulations'effect on enterprises profitability and profit quality depends on the strategic interaction among local governments,the scale and ownership of the enterprise,and regional differences.That is,the strategic interaction weakens the effect of environmental regulations on enterprise performance.Environmental regulations have a stronger influence on profitability and profit quality for large-scale,state-owned,and coastal enterprises.展开更多
The standardized production technical regulations of a new maize variety Jingdan No.15 are introduced from all aspects of land preparation,sowing,fertilization,intercropping,plant protection,interplanting,and harvesting.
The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should...The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should be interchangeable,so as to reduce product costs and reasonably economizethe use of energy and material resources.This paper intruduces the importance of formulating marine instrumentproduct standards,the present conditions and problems of marine product standards,and proposesrelated measures and suggestions to sovle the problems.展开更多
1 Scope This standard specifies the terms, definitions, classifications, brands, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage and quality certificate of ...1 Scope This standard specifies the terms, definitions, classifications, brands, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage and quality certificate of ceramic fiher and the products.展开更多
China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualitie...China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.展开更多
Standards Press of China (SPC), founded in October 1963, is the onlypublication center in China licensed to publish national standards, trade standards, and booksconcerned with standardization, quality, and other scie...Standards Press of China (SPC), founded in October 1963, is the onlypublication center in China licensed to publish national standards, trade standards, and booksconcerned with standardization, quality, and other science and technology. The main publications areas following: 1. National standards; 2. Trade standards; 3. Standards compilation booksand guides; 4. Books concerned with standardization; 5. Books of quality management andquality certification; 6. Books of environmental management and environmental certification.展开更多
In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative ...In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative materials, this paper presents extensible markup language (XML) based strategy for several important problems of data processing in network supported collaborative design, such as the representation of standard for the exchange of product model data (STEP) with XML in the product information expression and the management of XML documents using relational database. The paper gives a detailed exposition on how to clarify the mapping between XML structure and the relationship database structure and how XML-QL queries can be translated into structured query language (SQL) queries. Finally, the structure of data processing system based on XML is presented.展开更多
This paper begins by analysing the mutual influence between international trade and the environment, and then proceeds to explore the environment and trade conflicts. On the basis of sustainable development theories a...This paper begins by analysing the mutual influence between international trade and the environment, and then proceeds to explore the environment and trade conflicts. On the basis of sustainable development theories and the above discussion, the article suggests taking sustainable trade as a solution to the existing conflicts. This paper aims to find the way to strike a balance between international trade and environment based on the present situation in China.展开更多
There had been no standardized rules for citing ethical Kampo products used in clinical trials in journal articles. Although the name of a Kampo manufacturer was described in 77.9% of research articles, the name and r...There had been no standardized rules for citing ethical Kampo products used in clinical trials in journal articles. Although the name of a Kampo manufacturer was described in 77.9% of research articles, the name and ratios of crude drug components of Kampo formulas were not described in 77.5% of these papers. Considering the importance of proper characterization of interventions in the Consolidated Standards of Reporting Trials (CONSORT) checklist, we hereby propose the use of the Standards of Reporting Kampo Products (STORK) website, http://mpdb.nibiohn.go.jp/stork, as a reference for Kampo products. This will provide an official source on the internet for verified information on individual Kampo formulations for citation purposes in clinical research articles.展开更多
This paper presents the game of production technical standards between downstream and upstream suppliers on a manufacturing supply chain network when the two parties have different partnership densities, namely, the n...This paper presents the game of production technical standards between downstream and upstream suppliers on a manufacturing supply chain network when the two parties have different partnership densities, namely, the numbers of replaceable and mature manufacturing partners. We firstly constructed a manufacturing chain network and analyzed its three relationship structures among suppliers with the presence of different relationship densities, and found that all the three relationships brought about the game of production technical standards between partnership-rich and partnership-scanty suppliers. Then we built a two-party payoff matrix, and analyzed the two-party game and evolutionary stable strategy, based on replication dynamic equation and asymmetric evolutionary game theory. The evolutionary stable strategies of two parties under varying payoff parameters were validated through numerical simulation. Finally, we proposed some suggestions for both those manufacturers with more partners and fewer partners, respectively.展开更多
We introduce notions of ordinary and standard products of a-finite measures and prove their existence. This approach allows us to construct invariant extensions of ordinary and standard products of Haar measures. In p...We introduce notions of ordinary and standard products of a-finite measures and prove their existence. This approach allows us to construct invariant extensions of ordinary and standard products of Haar measures. In particular, we construct translation-invariant extensions of ordinary and standard Lebesgue measures on R∞ and Rogers-Fremlin measures on l∞, respectively, such that topological weights of quasi-metric spaces associated with these measures are maximal (i.e., 2c). We also solve some Fremlin problems concerned with an existence of uniform measures in Banach spaces.展开更多
The UK government set up a Herbal Medicines and Practitioners Working Group(HMPWG)to assess possibilities of:1.Setting up Statutory Regulation of Herbal Medicine Practitioners;2.Allowing continued public access to val...The UK government set up a Herbal Medicines and Practitioners Working Group(HMPWG)to assess possibilities of:1.Setting up Statutory Regulation of Herbal Medicine Practitioners;2.Allowing continued public access to valuable herbal medicines.On 26th March 2015 the HMPWG published the key recommendations after over a year of meetings and consultation with experts.展开更多
With the development of manufacturing,numerical control(NC) machining simulation has become a modern tool to obtain safe and reliable machining operations.Although some research and commercial software about NC machin...With the development of manufacturing,numerical control(NC) machining simulation has become a modern tool to obtain safe and reliable machining operations.Although some research and commercial software about NC machining simulations is available,most of them is oriented for G&M code.It is a low-level data model for computer numerical control(CNC),which has inherent drawbacks such as incomplete data and lack of accuracy.These limitations hinder the development of a real simulation system.Whereas,standard for the exchange of product data-compliant numerical control(STEP-NC) is a new and high-level data model for CNC.It provides rich information for CNC machine tools,which creates the condition for an informative and real simulation.Therefore,this paper proposes STEP-NC based high-level NC machining simulations solution integrated with computer-aided design/computeraided process planning/computer-aided manufacturing(CAD/CAPP/CAM).It turned out that the research provides a better informed simulation environment and promotes the development of modern manufacturing.展开更多
To overcome the limitations of commercial CAD and handbook form of knowledge expression, the Distributed Knowledge Information System (DKIS) for product design is proposed. The structure of DKIS and the key issues in...To overcome the limitations of commercial CAD and handbook form of knowledge expression, the Distributed Knowledge Information System (DKIS) for product design is proposed. The structure of DKIS and the key issues in its implementation are introduced; the method of knowledge store and transfer of DKIS is discussed. The mechanism of knowledge representation, acquisition and utilization, based on Internet network, is achieved. Based on the concept of function driven, integrated Artificial Neural Networks and Active Server Pages techniques, transplanting the trained ANN into DKIS system, a new method for retrieving knowledge in DKIS over Internet is achieved. Finally, a prototype of DKIS is developed to demonstrate the feasibility of the structure and constructional method of DKIS. The work pro-vides a scheme for speed knowledge acquisition and shortens the cycle of product development.展开更多
This paper uses semantic data modelling and CAD/CAPP/CAM integration to analyze the features defined in the STEP AP214, its characteristics of definition and distribution, and its influence on the complexity of CAD/CA...This paper uses semantic data modelling and CAD/CAPP/CAM integration to analyze the features defined in the STEP AP214, its characteristics of definition and distribution, and its influence on the complexity of CAD/CAPP/CAM application integration. A framework is developed for applications of CAD/CAPP/CAM integration based on the STEP to reduce the complexity of integration implementation. Two application program interfaces (API), namely, application protocol API and application API, are developed. The frameworks hierarchy structure and the application program interfaces between the layers make the integration of applications easier.展开更多
Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of g...Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201503127)~~
文摘The research reviewed standardized production technology of virus-free seed potato, including stem tip isolation, tissue culture seedling production, breeder's seed and protospecies production, and standard potato tubers' production, and concluded a set of standardized production technology for virus-free seed potato, in order to provide theoretical references for improving potato yield.
基金Under the auspices of Special Issue of National Remote Sensing Survey and Assessment of Eco-Environment Change Between 2000 and 2010(No.STSN-09-03)
文摘Northeast China has experienced frequent droughts over the past fifteen years. However, the effects of droughts on net primary productivity(NPP) in Northeast China remain unclear. In this paper, the droughts that occurred in Northeast China between 1999 and 2013 were identified using the Standardized Precipitation Evapotranspiration Index(SPEI). The NPP standardized anomaly index(NPP-SAI) was used to evaluate NPP anomalies. The years of 1999, 2000, 2001, and 2007 were further investigated in order to explore the influence of droughts on NPP at different time scales(3, 6, and 12 months). Based on the NPP-SAI of normal areas, we found droughts overall decreased NPP by 112.06 Tg C between 1999 and 2013. Lower temperatures at the beginning of the growing season could cause declines in NPP by shortening the length of the growing season. Mild drought or short-term drought with higher temperatures might increase NPP, and weak intensity droughts intensified the lag effects of droughts on NPP.
文摘The paper analyzes the characteristics of rice production in Heilongjiang Reclamation Area(HRA)and the achievements made through innovative research and practice,evaluates the standardized mode of rice cultivation and technical standards for rice production,which play a key role in guaranteeing the growth of grain total output in Heilongjiang reclamation area and make great contributions to the national grain safety.
基金This study is supported by the Dengfeng Strategy of the key discipline construction project,“Environmental Technology Economics”,at the Chinese Academy of Social Sciences[Grant number.2017-ZXKHJ]the National Social Science Fund Youth Fund Project:“Research on the effect Mechanism and Heterogeneity of Environmental Regulation on the Formation of Zombie Enterprises”[Grant number.19CJY028]+1 种基金General Project funded by the National Social Science Foundation:Economic Mechanism Analysis and Management Innovation System Study in Rural Water Environment Issues[Grant Number.10BJY064]the project funded by the Basic Business Fund of High Learning Institutions of the Central Government:Obstacles and Countermeasures to Spatial Integration of Economic Growth:with Yangtze River Economic Belt as an example[Grant number.20156322020201].
文摘Numerous studies evaluated the effects of end-of-pipe control environmental regulations(EER).However,few scholars discussed the effects of process management environmental regulations(PER),such as the China Cleaner Production Standards(CCPS)implemented by the country's Ministry of Ecology and Environment.Using data on China's manufacturing enterprises,this paper adopts the CCPS policies as quasi-natural experiments and uses differences-in-differences(DID)methods to analyze their effects on enterprise profitability and profit quality,respectively.The results show that:first,the CCPS significantly improve both profitability and profit quality;that is,the implementation of the environmental regulation policy plays a significant role in improving enterprise profit rates and cash flows.Second,for the profitability mediator effects,the short-term Porter effect of CCPS is not significant but shows the opposite during the lag period and significantly reduces the management cost and wage levels,comprehensively promoting enterprise profitability.Third,for the profit quality meditator effects,environmental regulations improve the enterprises'cash flow by reducing management costs and increasing government subsidies;however,its effect on bank credit subsidies is not significant.Fourth,for the moderator effects,the environmental regulations'effect on enterprises profitability and profit quality depends on the strategic interaction among local governments,the scale and ownership of the enterprise,and regional differences.That is,the strategic interaction weakens the effect of environmental regulations on enterprise performance.Environmental regulations have a stronger influence on profitability and profit quality for large-scale,state-owned,and coastal enterprises.
基金Supported by Special Funds for China Agriculture Research System(CARS-02)National Key Research and Development Plan(2018YFD0100103-2)。
文摘The standardized production technical regulations of a new maize variety Jingdan No.15 are introduced from all aspects of land preparation,sowing,fertilization,intercropping,plant protection,interplanting,and harvesting.
文摘The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should be interchangeable,so as to reduce product costs and reasonably economizethe use of energy and material resources.This paper intruduces the importance of formulating marine instrumentproduct standards,the present conditions and problems of marine product standards,and proposesrelated measures and suggestions to sovle the problems.
文摘1 Scope This standard specifies the terms, definitions, classifications, brands, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage and quality certificate of ceramic fiher and the products.
文摘China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.
文摘Standards Press of China (SPC), founded in October 1963, is the onlypublication center in China licensed to publish national standards, trade standards, and booksconcerned with standardization, quality, and other science and technology. The main publications areas following: 1. National standards; 2. Trade standards; 3. Standards compilation booksand guides; 4. Books concerned with standardization; 5. Books of quality management andquality certification; 6. Books of environmental management and environmental certification.
基金supported by National High Technology Research and Development Program of China (863 Program) (No. AA420060)
文摘In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative materials, this paper presents extensible markup language (XML) based strategy for several important problems of data processing in network supported collaborative design, such as the representation of standard for the exchange of product model data (STEP) with XML in the product information expression and the management of XML documents using relational database. The paper gives a detailed exposition on how to clarify the mapping between XML structure and the relationship database structure and how XML-QL queries can be translated into structured query language (SQL) queries. Finally, the structure of data processing system based on XML is presented.
基金Youth Science Fund of Chengdu University of Technology, No. 2005QJ10
文摘This paper begins by analysing the mutual influence between international trade and the environment, and then proceeds to explore the environment and trade conflicts. On the basis of sustainable development theories and the above discussion, the article suggests taking sustainable trade as a solution to the existing conflicts. This paper aims to find the way to strike a balance between international trade and environment based on the present situation in China.
文摘There had been no standardized rules for citing ethical Kampo products used in clinical trials in journal articles. Although the name of a Kampo manufacturer was described in 77.9% of research articles, the name and ratios of crude drug components of Kampo formulas were not described in 77.5% of these papers. Considering the importance of proper characterization of interventions in the Consolidated Standards of Reporting Trials (CONSORT) checklist, we hereby propose the use of the Standards of Reporting Kampo Products (STORK) website, http://mpdb.nibiohn.go.jp/stork, as a reference for Kampo products. This will provide an official source on the internet for verified information on individual Kampo formulations for citation purposes in clinical research articles.
基金Supported by the Science and Technology Development Strategy Research Project of Tianjin(13ZLZLZF08900)
文摘This paper presents the game of production technical standards between downstream and upstream suppliers on a manufacturing supply chain network when the two parties have different partnership densities, namely, the numbers of replaceable and mature manufacturing partners. We firstly constructed a manufacturing chain network and analyzed its three relationship structures among suppliers with the presence of different relationship densities, and found that all the three relationships brought about the game of production technical standards between partnership-rich and partnership-scanty suppliers. Then we built a two-party payoff matrix, and analyzed the two-party game and evolutionary stable strategy, based on replication dynamic equation and asymmetric evolutionary game theory. The evolutionary stable strategies of two parties under varying payoff parameters were validated through numerical simulation. Finally, we proposed some suggestions for both those manufacturers with more partners and fewer partners, respectively.
基金Supported by National Science Foundation of Georgia (Grants Nos. GNSF/ST 08/3-391, Sh. Rustaveli GNSF/ST 09_144-3-105)
文摘We introduce notions of ordinary and standard products of a-finite measures and prove their existence. This approach allows us to construct invariant extensions of ordinary and standard products of Haar measures. In particular, we construct translation-invariant extensions of ordinary and standard Lebesgue measures on R∞ and Rogers-Fremlin measures on l∞, respectively, such that topological weights of quasi-metric spaces associated with these measures are maximal (i.e., 2c). We also solve some Fremlin problems concerned with an existence of uniform measures in Banach spaces.
文摘The UK government set up a Herbal Medicines and Practitioners Working Group(HMPWG)to assess possibilities of:1.Setting up Statutory Regulation of Herbal Medicine Practitioners;2.Allowing continued public access to valuable herbal medicines.On 26th March 2015 the HMPWG published the key recommendations after over a year of meetings and consultation with experts.
基金supported by National Natural Science Foundation of China (No.51205054)National Key Technology Research and Development Program During the Twelfth Five-year Plan(Nos.2012BAF10B11,2012BAF12B08)
文摘With the development of manufacturing,numerical control(NC) machining simulation has become a modern tool to obtain safe and reliable machining operations.Although some research and commercial software about NC machining simulations is available,most of them is oriented for G&M code.It is a low-level data model for computer numerical control(CNC),which has inherent drawbacks such as incomplete data and lack of accuracy.These limitations hinder the development of a real simulation system.Whereas,standard for the exchange of product data-compliant numerical control(STEP-NC) is a new and high-level data model for CNC.It provides rich information for CNC machine tools,which creates the condition for an informative and real simulation.Therefore,this paper proposes STEP-NC based high-level NC machining simulations solution integrated with computer-aided design/computeraided process planning/computer-aided manufacturing(CAD/CAPP/CAM).It turned out that the research provides a better informed simulation environment and promotes the development of modern manufacturing.
基金the National Natural Science Foundation of China (No.59990472).
文摘To overcome the limitations of commercial CAD and handbook form of knowledge expression, the Distributed Knowledge Information System (DKIS) for product design is proposed. The structure of DKIS and the key issues in its implementation are introduced; the method of knowledge store and transfer of DKIS is discussed. The mechanism of knowledge representation, acquisition and utilization, based on Internet network, is achieved. Based on the concept of function driven, integrated Artificial Neural Networks and Active Server Pages techniques, transplanting the trained ANN into DKIS system, a new method for retrieving knowledge in DKIS over Internet is achieved. Finally, a prototype of DKIS is developed to demonstrate the feasibility of the structure and constructional method of DKIS. The work pro-vides a scheme for speed knowledge acquisition and shortens the cycle of product development.
文摘This paper uses semantic data modelling and CAD/CAPP/CAM integration to analyze the features defined in the STEP AP214, its characteristics of definition and distribution, and its influence on the complexity of CAD/CAPP/CAM application integration. A framework is developed for applications of CAD/CAPP/CAM integration based on the STEP to reduce the complexity of integration implementation. Two application program interfaces (API), namely, application protocol API and application API, are developed. The frameworks hierarchy structure and the application program interfaces between the layers make the integration of applications easier.
基金Department of Science and Technology,Government of India for providing financial support under the scheme FIST(No.SR/FST/ETI-388/2015)。
文摘Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.