One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any ...One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any change in these parameters could finally affect on specific charge and specific drilling. There are mainly two groups of methods for tunnel blast design categorized based on the parallel cuts and angular cuts. In this research, a software for tunnel blast design was developed to analyze the effect and sensitiveness of blasthole diameter and the tunnel face area on blasting results in different blast design models. Using the software, it is quickly possible to determine specific charge, specific drilling and number of blastholes for each blast design model. The relations between both of blasthole diameters and the tunnel face area with the above parameters in different blast design models were then investigated to yield a set of equations with the highest correlations to compare the methods. The results showed that angular method requires more blasthole numbers than parallel method in similar condition(blasthole diameter and tunnel face area). Moreover, the specific charge values yielded by the two methods are approximately the same and very close together.展开更多
<div style="text-align:justify;"> With the wide application of renewable energy, energy storage technology has become a research hotspot. In order to overcome the shortcomings of energy loss caused by ...<div style="text-align:justify;"> With the wide application of renewable energy, energy storage technology has become a research hotspot. In order to overcome the shortcomings of energy loss caused by compression heating in compressed air energy storage technology, a novel constant-pressure pumped hydro combined with compressed air energy storage system was proposed. To deepen the understanding of the system and make the analysis closer to reality, this paper adopted an off-design model of the compressor to calculate and analyze the effect of key parameters on system thermodynamics performance. In addition, the results of this paper were compared with previous research results, and it was found that the current efficiency considering the off-design model of compressor was generally 2% - 5% higher than the previous efficiency. With increased preset pressure or with decreased terminal pressure, both the previous efficiency and current efficiency of the system increased. The exergy destruction coefficient of the throttle valve reached 4%. System efficiency was more sensitive to changes in water pump efficiency and hydroturbine efficiency. </div>展开更多
The angular position controller is system （EHSAS） to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its...The angular position controller is system （EHSAS） to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its design model is verified on the state-space model of EHSAS by using simulation program SIMULINK. Real data used to test the system. Simulation results give a good agreement for the controller and also for the state-space model.展开更多
A generic design model for evolutionary algorithms is proposed in this paper. The model, which was described by UML in details, focuses on the key concepts and mechanisms in evolutionary algorithms. The model not only...A generic design model for evolutionary algorithms is proposed in this paper. The model, which was described by UML in details, focuses on the key concepts and mechanisms in evolutionary algorithms. The model not only achieves separation of concerns and encapsulation of implementations by classification and abstraction of those concepts, it also has a flexible architecture due to the application of design patterns. As a result, the model is reusable, extendible, easy to understand, easy to use, and easy to test. A large number of experiments applying the model to solve many different problems adequately illustrate the generality and effec-tivity of the model.展开更多
Today, more people are riding bicycles than ever before--and the numbers keep growing. This is due in part to a greater awareness of environmental issues and growing health consciousness. Another factor driving the in...Today, more people are riding bicycles than ever before--and the numbers keep growing. This is due in part to a greater awareness of environmental issues and growing health consciousness. Another factor driving the increasing number of women bicyclists today is many designer bicycles now available. Still, these bicycles reflect the subjective sensibilities of their designers, and there is no guarantee that they will always match an increasingly diverse array of consumer values. In response to this challenge, our study sets out to build a bicycle design model based on fashion styles popular with young women in their 20s. Fashion analysis and bicycle design analysis used statistical science, such as cluster analysis, principal component analysis, and analytic hierarchy process （AHP）. After that, we designed a new bicycle using computer-aided design （CAD） from the analysis results. Finally, the approach model developed in this study was confirmed to be effective by an interview with the company.展开更多
The main focus of this paper is the analysis on how social business recent management proposals fit to a media/journalistic business environment. The discussion was based on three research questions focusing on： the ...The main focus of this paper is the analysis on how social business recent management proposals fit to a media/journalistic business environment. The discussion was based on three research questions focusing on： the drivers and the constraints of disruption innovation strategies; the adequate social business design framework to promote innovation; and an evaluation over the practices/experiences related to disruption, innovation, and creativity in journalistic businesses. A conceptual framework the Latour/Law Actor-Network Theory （ANT） has been taken as. Six possible dimensions of action to make this framework valuable some successful practices have also been identified, and in this paper the authors view over these concepts. The main conclusion goes through the understanding of journalistic culture and legitimacy embedded for centuries over society, and to change this will depend on multiple enablers.展开更多
This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher＇s class. The researcher guided the preservice teachers to gather various prisms, pyramids, a...This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher＇s class. The researcher guided the preservice teachers to gather various prisms, pyramids, and spheres to study the total surface areas and volumes. At the end of the integrated models, the test scores showed closed relationships in the concurrent instructional strategies of the integrated models. The researcher therefore, recommended the design models for the teaching and learning of solids in mathematics.展开更多
Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure（...Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure（FBS） model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model（CECD） for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions（BOA）, and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.展开更多
<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transurani...<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transuranium elements,which would remain radioactive for 10~4 to 10~8 years.In this brief communication,essential concepts and engineering elements related to high-level nuclear waste disposal are described.Conceptual design models are described and discussed considering the long-time scale activity of spent nuclear fuel or high level waste.Notions of physical and chemical barriers to contain nuclear waste are highiightened.Concerns regarding integrity,self-irradiation induced decomposition and thermal effects of decay heat on the spent nuclear fuel are also discussed.The question of retrievability of spent nuclear fuel after disposal is considered.展开更多
Society is becoming increasingly dependent on cyberspace for both business and pleasure. Cyber attackers continue to attack organizational computer networks, as those same computer networks become increasing critical ...Society is becoming increasingly dependent on cyberspace for both business and pleasure. Cyber attackers continue to attack organizational computer networks, as those same computer networks become increasing critical to organizational business process. Strategic planning and managing IT security risks play an important role in the business and government planning process. Deploying defense in depth security measures can ensure that organizations continue to function in times of crisis. This quantitative study explores whether the Latin Square Design (LSD) model can be effectively applied to the prioritization of cybersecurity threats and to the linking of information assurance defense in-depth measures to those threats. The methods used in this study consisted of scanning 10 Cybersecurity Websites such as the Department of Homeland Security US CERT (United States-Computer Emergency Readiness Team [1]) and the SANS Institute (SysAdmin, Audit, Network and Security [2]) using the Likert Scale Model for the Website’s top ten list of cyber threats facing organizations and the network defense in depth measures to fight those threats. A comparison of each cybersecurity threats was then made using LSD to determine whether the Likert scale and the LSD model could be effectively applied to prioritize information assurance measures to protect organizational computing devices. The findings of the research reject the H0 null hypothesis that LSD does not affect the relationship between the ranking of 10 Cybersecurity websites top ten cybersecurity threats dependent variables and the independent variables of defense in depth measures used in protecting organizational devices against cyber-attacks.展开更多
Gas turbines are considered as one of the leading internal combustion engines in modern air transportation due to its favourable power to weight ratio and its continuous combustion process. Recent research focus has b...Gas turbines are considered as one of the leading internal combustion engines in modern air transportation due to its favourable power to weight ratio and its continuous combustion process. Recent research focus has been concerned with performance improvements aimed at reduced fuel consumption and hence reduced impact on the environment. This study is aimed at using theoretical and computational methods to model the operation and performance a turbojet gas turbine engine. The commercial software GasTurb13 was used for the theoretical simulation while Microsoft Excel was used for the analytical study. GasTurb13 solved the model using pseudo-perfect gas models i.e. component maps since the specific gas ratio could not be inputted into the solver. The effect of changes in the Mach number and altitude on the engine performance was studied. Also the effect of changes in the compressor pressure ratio, the turbine inlet temperature and the afterburner exit temperature were also studied. Results obtained showed the optimum pressure ratio at maximum thrust constraint to be 16.78 for the turbojet engine operating at Mach number (Ma) = 0.8 and altitude = 10,000 m, Turbine inlet temperature (TIT) = 1200 K and Afterburner exit temperature = 1800 K.展开更多
Automatically mapping a requirement specification to design model in Software Engineering is an open complex problem. Existing methods use a complex manual process that use the knowledge from the requirement specifica...Automatically mapping a requirement specification to design model in Software Engineering is an open complex problem. Existing methods use a complex manual process that use the knowledge from the requirement specification/modeling and the design, and try to find a good match between them. The key task done by designers is to convert a natural language based requirement specification (or corresponding UML based representation) into a predominantly computer language based design model—thus the process is very complex as there is a very large gap between our natural language and computer language. Moreover, this is not just a simple language conversion, but rather a complex knowledge conversion that can lead to meaningful design implementation. In this paper, we describe an automated method to map Requirement Model to Design Model and thus automate/partially automate the Structured Design (SD) process. We believe, this is the first logical step in mapping a more complex requirement specification to design model. We call it IRTDM (Intelligent Agent based requirement model to design model mapping). The main theme of IRTDM is to use some AI (Artificial Intelligence) based algorithms, semantic representation using Ontology or Predicate Logic, design structures using some well known design framework and Machine Learning algorithms for learning over time. Semantics help convert natural language based requirement specification (and associated UML representation) into high level design model followed by mapping to design structures. AI method can also be used to convert high level design structures into lower level design which then can be refined further by some manual and/or semi automated process. We emphasize that automation is one of the key ways to minimize the software cost, and is very important for all, especially, for the “Design for the Bottom 90% People” or BOP (Base of the Pyramid People).展开更多
The desire to deliver measured amount of insulin continuously to patients with type I diabetes, for glycemic control, has attracted a lot of attention. Continuous subcutaneous insulin infusion has seen some success in...The desire to deliver measured amount of insulin continuously to patients with type I diabetes, for glycemic control, has attracted a lot of attention. Continuous subcutaneous insulin infusion has seen some success in recent years. However, occlusion of insulin delivery may prevent the patient from receiving the prescribed dosage, with adverse consequence. An in vitro study of insulin delivery is performed, using different insulin pumps, insulin analogs and operating conditions. The aim is to identify incidences of occlusion due to bubble formation in the infusion line. A detailed statistical analysis was performed on the data collected to determine any significant differences and deviations in insulin delivery rates that might be due to factors such as: pump type, the set basal flow rate, insulin type, vibration, and possible insulin occlusion due to air bubble formation within the infusion line. Our findings from the Graeco-Latin Square design model show that there are statistical differences due to the devices, and statistical identifiable clusters are used to distinguish the devices. Such hierarchical models used to describe the analyses, include the flow rate, the pump types, and the activity level.展开更多
Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy eval...Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy evaluation method is researched,thus the applicability of each algorithm is obtained.Firstly,the naval ship synthesis model is introduced to design process,value and application status of synthesis model in integrated design is then exposed.Then the applicability of single target and multi targets SA algorithm is improved,and the quick generation of naval ship projects is done.After that,multiple projects evaluation method based on Vague fuzzy set is introduced to established the intelligent evaluation model,which can integrate effectively the quantitative and qualitative indexes.At last,the analysis of results comparison shows the advancement and rationality of each method.The example shows the integrated design process researched in this paper can be a great orientation of naval ship project design,and can also be used in other parts of naval ship development.展开更多
With the continuous improvement of signal processing accuracy requirements in modern electronic systems,the demand for high-precision analog-to-digital converters(ADCs)is increasing.Sigma-Delta modulator,as the most i...With the continuous improvement of signal processing accuracy requirements in modern electronic systems,the demand for high-precision analog-to-digital converters(ADCs)is increasing.Sigma-Delta modulator,as the most important component of high-precision ADC,is widely used in high-quality audio,high-precision instrument measurement,and other fields due to its advantages of high precision,strong noise resistance,and low hardware cost.This article designs a discrete structure third-order four-bit high-precision Sigma-Delta modulator through modeling,with an oversampling rate set to 512.Under ideal conditions,the simulation results show that the SDNR reaches 152.7db and the ENOB is 25.24bits.After introducing non-ideal noise,the system performance has decreased.The simulation results show that the SDNR is as high as 124.5db and the ENOB is 20.39bits.This indicates that the design can achieve high-precision conversion and provide assistance for further research in the future.展开更多
The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fews...The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fewstudies have addressed the issue of model equivalence under penetration loading.This study employs numerical simulation to validate an experiment with an ogival-nosed projectile penetrating a Q345 steel plate.Four equivalent stiffened plate methods are proposed based on the area,flexural modulus,moment of inertia,and thickness.The results indicate that thickness equivalence(DM4)is unsuitable for penetration-loaded stiffened plates,except under low-speed,nonpenetrating through impacts,and yields less accuracy than DM1/DM3.DM1,DM2,and DM3 each perform optimally with specific velocity ranges:DM1 at very low(critical)and high velocities,DM3 at low velocities,and DM2 at high speeds.Furthermore,in penetration scenarios,T-shaped stiffeners can be replacedwith rectangular ones,as both exhibit similar failure behaviors and deflection trends,simplifying the design while preserving key structural characteristics.These findings provide valuable insights into the design of protective ship structures.展开更多
The advances of computer graphics and imape processing have made it possible to design advertisements by computers. Presently, many commercial systems have come into being, such as CorelDraw and PhotoShop. All of them...The advances of computer graphics and imape processing have made it possible to design advertisements by computers. Presently, many commercial systems have come into being, such as CorelDraw and PhotoShop. All of them are developed out of the idea of graphics system or image system. For the ads designer, what is actually needed is a system developed from the point of view of ads design domain. In this paper, an object-oriented design model called OOADS is presented, around which five categories of operations, namely CMPDS (Clip / Modify / Paste / Draw/ Select ) are organized. Key approaches with the operations such as representation and organization of objects, virtual clipping, shadow images are demonstrated. In the end, the implementation of OOADS is discussed.展开更多
文摘One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any change in these parameters could finally affect on specific charge and specific drilling. There are mainly two groups of methods for tunnel blast design categorized based on the parallel cuts and angular cuts. In this research, a software for tunnel blast design was developed to analyze the effect and sensitiveness of blasthole diameter and the tunnel face area on blasting results in different blast design models. Using the software, it is quickly possible to determine specific charge, specific drilling and number of blastholes for each blast design model. The relations between both of blasthole diameters and the tunnel face area with the above parameters in different blast design models were then investigated to yield a set of equations with the highest correlations to compare the methods. The results showed that angular method requires more blasthole numbers than parallel method in similar condition(blasthole diameter and tunnel face area). Moreover, the specific charge values yielded by the two methods are approximately the same and very close together.
文摘<div style="text-align:justify;"> With the wide application of renewable energy, energy storage technology has become a research hotspot. In order to overcome the shortcomings of energy loss caused by compression heating in compressed air energy storage technology, a novel constant-pressure pumped hydro combined with compressed air energy storage system was proposed. To deepen the understanding of the system and make the analysis closer to reality, this paper adopted an off-design model of the compressor to calculate and analyze the effect of key parameters on system thermodynamics performance. In addition, the results of this paper were compared with previous research results, and it was found that the current efficiency considering the off-design model of compressor was generally 2% - 5% higher than the previous efficiency. With increased preset pressure or with decreased terminal pressure, both the previous efficiency and current efficiency of the system increased. The exergy destruction coefficient of the throttle valve reached 4%. System efficiency was more sensitive to changes in water pump efficiency and hydroturbine efficiency. </div>
文摘The angular position controller is system （EHSAS） to control the output of the rotary applied to electro-hydraulic servo actuator actuator. It works as a compensator based on the frequency response of the EHSAS. Its design model is verified on the state-space model of EHSAS by using simulation program SIMULINK. Real data used to test the system. Simulation results give a good agreement for the controller and also for the state-space model.
基金Supported by the National Natural Science Foundation of China(70071042,60073043,60133010)
文摘A generic design model for evolutionary algorithms is proposed in this paper. The model, which was described by UML in details, focuses on the key concepts and mechanisms in evolutionary algorithms. The model not only achieves separation of concerns and encapsulation of implementations by classification and abstraction of those concepts, it also has a flexible architecture due to the application of design patterns. As a result, the model is reusable, extendible, easy to understand, easy to use, and easy to test. A large number of experiments applying the model to solve many different problems adequately illustrate the generality and effec-tivity of the model.
文摘Today, more people are riding bicycles than ever before--and the numbers keep growing. This is due in part to a greater awareness of environmental issues and growing health consciousness. Another factor driving the increasing number of women bicyclists today is many designer bicycles now available. Still, these bicycles reflect the subjective sensibilities of their designers, and there is no guarantee that they will always match an increasingly diverse array of consumer values. In response to this challenge, our study sets out to build a bicycle design model based on fashion styles popular with young women in their 20s. Fashion analysis and bicycle design analysis used statistical science, such as cluster analysis, principal component analysis, and analytic hierarchy process （AHP）. After that, we designed a new bicycle using computer-aided design （CAD） from the analysis results. Finally, the approach model developed in this study was confirmed to be effective by an interview with the company.
文摘The main focus of this paper is the analysis on how social business recent management proposals fit to a media/journalistic business environment. The discussion was based on three research questions focusing on： the drivers and the constraints of disruption innovation strategies; the adequate social business design framework to promote innovation; and an evaluation over the practices/experiences related to disruption, innovation, and creativity in journalistic businesses. A conceptual framework the Latour/Law Actor-Network Theory （ANT） has been taken as. Six possible dimensions of action to make this framework valuable some successful practices have also been identified, and in this paper the authors view over these concepts. The main conclusion goes through the understanding of journalistic culture and legitimacy embedded for centuries over society, and to change this will depend on multiple enablers.
文摘This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher＇s class. The researcher guided the preservice teachers to gather various prisms, pyramids, and spheres to study the total surface areas and volumes. At the end of the integrated models, the test scores showed closed relationships in the concurrent instructional strategies of the integrated models. The researcher therefore, recommended the design models for the teaching and learning of solids in mathematics.
基金Supported by National Natural Science Foundation of China (Grant Nos.51375496,51205409)
文摘Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure（FBS） model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model（CECD） for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions（BOA）, and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.
文摘<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transuranium elements,which would remain radioactive for 10~4 to 10~8 years.In this brief communication,essential concepts and engineering elements related to high-level nuclear waste disposal are described.Conceptual design models are described and discussed considering the long-time scale activity of spent nuclear fuel or high level waste.Notions of physical and chemical barriers to contain nuclear waste are highiightened.Concerns regarding integrity,self-irradiation induced decomposition and thermal effects of decay heat on the spent nuclear fuel are also discussed.The question of retrievability of spent nuclear fuel after disposal is considered.
文摘Society is becoming increasingly dependent on cyberspace for both business and pleasure. Cyber attackers continue to attack organizational computer networks, as those same computer networks become increasing critical to organizational business process. Strategic planning and managing IT security risks play an important role in the business and government planning process. Deploying defense in depth security measures can ensure that organizations continue to function in times of crisis. This quantitative study explores whether the Latin Square Design (LSD) model can be effectively applied to the prioritization of cybersecurity threats and to the linking of information assurance defense in-depth measures to those threats. The methods used in this study consisted of scanning 10 Cybersecurity Websites such as the Department of Homeland Security US CERT (United States-Computer Emergency Readiness Team [1]) and the SANS Institute (SysAdmin, Audit, Network and Security [2]) using the Likert Scale Model for the Website’s top ten list of cyber threats facing organizations and the network defense in depth measures to fight those threats. A comparison of each cybersecurity threats was then made using LSD to determine whether the Likert scale and the LSD model could be effectively applied to prioritize information assurance measures to protect organizational computing devices. The findings of the research reject the H0 null hypothesis that LSD does not affect the relationship between the ranking of 10 Cybersecurity websites top ten cybersecurity threats dependent variables and the independent variables of defense in depth measures used in protecting organizational devices against cyber-attacks.
文摘Gas turbines are considered as one of the leading internal combustion engines in modern air transportation due to its favourable power to weight ratio and its continuous combustion process. Recent research focus has been concerned with performance improvements aimed at reduced fuel consumption and hence reduced impact on the environment. This study is aimed at using theoretical and computational methods to model the operation and performance a turbojet gas turbine engine. The commercial software GasTurb13 was used for the theoretical simulation while Microsoft Excel was used for the analytical study. GasTurb13 solved the model using pseudo-perfect gas models i.e. component maps since the specific gas ratio could not be inputted into the solver. The effect of changes in the Mach number and altitude on the engine performance was studied. Also the effect of changes in the compressor pressure ratio, the turbine inlet temperature and the afterburner exit temperature were also studied. Results obtained showed the optimum pressure ratio at maximum thrust constraint to be 16.78 for the turbojet engine operating at Mach number (Ma) = 0.8 and altitude = 10,000 m, Turbine inlet temperature (TIT) = 1200 K and Afterburner exit temperature = 1800 K.
文摘Automatically mapping a requirement specification to design model in Software Engineering is an open complex problem. Existing methods use a complex manual process that use the knowledge from the requirement specification/modeling and the design, and try to find a good match between them. The key task done by designers is to convert a natural language based requirement specification (or corresponding UML based representation) into a predominantly computer language based design model—thus the process is very complex as there is a very large gap between our natural language and computer language. Moreover, this is not just a simple language conversion, but rather a complex knowledge conversion that can lead to meaningful design implementation. In this paper, we describe an automated method to map Requirement Model to Design Model and thus automate/partially automate the Structured Design (SD) process. We believe, this is the first logical step in mapping a more complex requirement specification to design model. We call it IRTDM (Intelligent Agent based requirement model to design model mapping). The main theme of IRTDM is to use some AI (Artificial Intelligence) based algorithms, semantic representation using Ontology or Predicate Logic, design structures using some well known design framework and Machine Learning algorithms for learning over time. Semantics help convert natural language based requirement specification (and associated UML representation) into high level design model followed by mapping to design structures. AI method can also be used to convert high level design structures into lower level design which then can be refined further by some manual and/or semi automated process. We emphasize that automation is one of the key ways to minimize the software cost, and is very important for all, especially, for the “Design for the Bottom 90% People” or BOP (Base of the Pyramid People).
文摘The desire to deliver measured amount of insulin continuously to patients with type I diabetes, for glycemic control, has attracted a lot of attention. Continuous subcutaneous insulin infusion has seen some success in recent years. However, occlusion of insulin delivery may prevent the patient from receiving the prescribed dosage, with adverse consequence. An in vitro study of insulin delivery is performed, using different insulin pumps, insulin analogs and operating conditions. The aim is to identify incidences of occlusion due to bubble formation in the infusion line. A detailed statistical analysis was performed on the data collected to determine any significant differences and deviations in insulin delivery rates that might be due to factors such as: pump type, the set basal flow rate, insulin type, vibration, and possible insulin occlusion due to air bubble formation within the infusion line. Our findings from the Graeco-Latin Square design model show that there are statistical differences due to the devices, and statistical identifiable clusters are used to distinguish the devices. Such hierarchical models used to describe the analyses, include the flow rate, the pump types, and the activity level.
基金supported by “The Fundamental Research Funds for the Central Universities”(3132014318)
文摘Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy evaluation method is researched,thus the applicability of each algorithm is obtained.Firstly,the naval ship synthesis model is introduced to design process,value and application status of synthesis model in integrated design is then exposed.Then the applicability of single target and multi targets SA algorithm is improved,and the quick generation of naval ship projects is done.After that,multiple projects evaluation method based on Vague fuzzy set is introduced to established the intelligent evaluation model,which can integrate effectively the quantitative and qualitative indexes.At last,the analysis of results comparison shows the advancement and rationality of each method.The example shows the integrated design process researched in this paper can be a great orientation of naval ship project design,and can also be used in other parts of naval ship development.
文摘With the continuous improvement of signal processing accuracy requirements in modern electronic systems,the demand for high-precision analog-to-digital converters(ADCs)is increasing.Sigma-Delta modulator,as the most important component of high-precision ADC,is widely used in high-quality audio,high-precision instrument measurement,and other fields due to its advantages of high precision,strong noise resistance,and low hardware cost.This article designs a discrete structure third-order four-bit high-precision Sigma-Delta modulator through modeling,with an oversampling rate set to 512.Under ideal conditions,the simulation results show that the SDNR reaches 152.7db and the ENOB is 25.24bits.After introducing non-ideal noise,the system performance has decreased.The simulation results show that the SDNR is as high as 124.5db and the ENOB is 20.39bits.This indicates that the design can achieve high-precision conversion and provide assistance for further research in the future.
基金supported by Natural Science Foundation of Fujian Province(2022I0019)Scientific Research Foundation for Jimei University(ZQ2024041,ZQ2024042).
文摘The penetration of ogival-nosed projectiles into ship plates represents a complex impact dynamics issue essential for analyzing structural failuremechanisms.Although stiffenedplates are vital in ship construction,fewstudies have addressed the issue of model equivalence under penetration loading.This study employs numerical simulation to validate an experiment with an ogival-nosed projectile penetrating a Q345 steel plate.Four equivalent stiffened plate methods are proposed based on the area,flexural modulus,moment of inertia,and thickness.The results indicate that thickness equivalence(DM4)is unsuitable for penetration-loaded stiffened plates,except under low-speed,nonpenetrating through impacts,and yields less accuracy than DM1/DM3.DM1,DM2,and DM3 each perform optimally with specific velocity ranges:DM1 at very low(critical)and high velocities,DM3 at low velocities,and DM2 at high speeds.Furthermore,in penetration scenarios,T-shaped stiffeners can be replacedwith rectangular ones,as both exhibit similar failure behaviors and deflection trends,simplifying the design while preserving key structural characteristics.These findings provide valuable insights into the design of protective ship structures.
文摘The advances of computer graphics and imape processing have made it possible to design advertisements by computers. Presently, many commercial systems have come into being, such as CorelDraw and PhotoShop. All of them are developed out of the idea of graphics system or image system. For the ads designer, what is actually needed is a system developed from the point of view of ads design domain. In this paper, an object-oriented design model called OOADS is presented, around which five categories of operations, namely CMPDS (Clip / Modify / Paste / Draw/ Select ) are organized. Key approaches with the operations such as representation and organization of objects, virtual clipping, shadow images are demonstrated. In the end, the implementation of OOADS is discussed.
