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An Improved Hybrid Deep Learning Approach for Security Requirements Classification
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作者 Shoaib Hassan QianmuLi +2 位作者 Muhammad Zubair Rakan AAlsowail Muhammad Umair 《Computers, Materials & Continua》 2025年第3期4041-4067,共27页
As the trend to use the latestmachine learning models to automate requirements engineering processes continues,security requirements classification is tuning into the most researched field in the software engineering ... As the trend to use the latestmachine learning models to automate requirements engineering processes continues,security requirements classification is tuning into the most researched field in the software engineering community.Previous literature studies have proposed numerousmodels for the classification of security requirements.However,adopting those models is constrained due to the lack of essential datasets permitting the repetition and generalization of studies employing more advanced machine learning algorithms.Moreover,most of the researchers focus only on the classification of requirements with security keywords.They did not consider other nonfunctional requirements(NFR)directly or indirectly related to security.This has been identified as a significant research gap in security requirements engineering.The major objective of this study is to propose a security requirements classification model that categorizes security and other relevant security requirements.We use PROMISE_exp and DOSSPRE,the two most commonly used datasets in the software engineering community.The proposed methodology consists of two steps.In the first step,we analyze all the nonfunctional requirements and their relation with security requirements.We found 10 NFRs that have a strong relationship with security requirements.In the second step,we categorize those NFRs in the security requirements category.Our proposedmethodology is a hybridmodel based on the ConvolutionalNeural Network(CNN)and Extreme Gradient Boosting(XGBoost)models.Moreover,we evaluate the model by updating the requirement type column with a binary classification column in the dataset to classify the requirements into security and non-security categories.The performance is evaluated using four metrics:recall,precision,accuracy,and F1 Score with 20 and 28 epochs number and batch size of 32 for PROMISE_exp and DOSSPRE datasets and achieved 87.3%and 85.3%accuracy,respectively.The proposed study shows an enhancement in metrics values compared to the previous literature studies.This is a proof of concept for systematizing the evaluation of security recognition in software systems during the early phases of software development. 展开更多
关键词 requirements engineering security requirements deep learning CNN XGBoost CLASSIFICATION
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Large Language Models in Software Engineering Education: A Preliminary Study on Software Requirements Engineering Courses
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作者 Feng Chen Shaomin Zhu +1 位作者 Xin Liu Ying Qian 《计算机教育》 2025年第3期24-33,共10页
The advent of large language models(LLMs)has made knowledge acquisition and content creation increasingly easier and cheaper,which in turn redefines learning and urges transformation in software engineering education.... The advent of large language models(LLMs)has made knowledge acquisition and content creation increasingly easier and cheaper,which in turn redefines learning and urges transformation in software engineering education.To do so,there is a need to understand the impact of LLMs on software engineering education.In this paper,we conducted a preliminary case study on three software requirements engineering classes where students are allowed to use LLMs to assist in their projects.Based on the students’experience,performance,and feedback from a survey conducted at the end of the courses,we characterized the challenges and benefits of applying LLMs in software engineering education.This research contributes to the ongoing discourse on the integration of LLMs in education,emphasizing both their prominent potential and the need for balanced,mindful usage. 展开更多
关键词 Large language models Software engineering Software requirements engineering EDUCATION
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Communications in Urban Low-Altitude Drone Logistics Networks:Requirements,Solutions and Challenges
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作者 Duan Ruiyang Mao Yinian +1 位作者 Chen Jialong Song Jian 《China Communications》 2025年第9期37-47,共11页
Communications system has a signifi-cant impact on both operational safety and logisti-cal efficiency within low-altitude drone logistics net-works.Aiming at providing a systematic investiga-tion of real-world communi... Communications system has a signifi-cant impact on both operational safety and logisti-cal efficiency within low-altitude drone logistics net-works.Aiming at providing a systematic investiga-tion of real-world communication requirements and challenges encountered in Meituan UAV’s daily oper-ations,this article first introduces the operational sce-narios within current drone logistics networks and an-alyzes the related communication requirements.Then,the current communication solution and its inherent bottlenecks are elaborated.Finally,this paper explores emerging technologies and examines their application prospects in drone logistics networks. 展开更多
关键词 communication challenges communication requirements drone logistics low-altitude economy
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Exporting Perfumes to China:Key Compliance and Import Requirements
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作者 Jarius Ji 《China Detergent & Cosmetics》 2025年第2期12-15,共4页
China's perfume market has been experiencing significant growth.The “2024 China Perfume and Fragrance White Paper”,jointly published by Eternal Group,DSM-Firmenich,and Ipsos in September 2024,reveals that the ma... China's perfume market has been experiencing significant growth.The “2024 China Perfume and Fragrance White Paper”,jointly published by Eternal Group,DSM-Firmenich,and Ipsos in September 2024,reveals that the market surged from 11.4 billion yuan in 2018 to 22.9 billion yuan in 2023,achieving a compound annual growth rate(CAGR) of 15%.With projections estimating a rise to 44 billion yuan by 2028 at a 14% CAGR,the sector's long-term growth prospects remain strong. 展开更多
关键词 growth prospects white paper China COMPLIANCE perfumes perfume market import requirements
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Beamforming Design for Transmissive RISs-Aided Indoor Communications Under Different Service Requirements
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作者 Pang Lihua Wang Yue +3 位作者 Zhang Yang Zhang Yiteng Chen Yijian Wang Anyi 《China Communications》 2025年第8期58-75,共18页
As emerging services continue to be explored,indoor communications geared towards different user requirements will face severe challenges such as larger penetration losses and more critical multipath issues,leading to... As emerging services continue to be explored,indoor communications geared towards different user requirements will face severe challenges such as larger penetration losses and more critical multipath issues,leading to difficulties in achieving flexible coverage.In this paper,we introduce transmissive reconfigurable intelligent surfaces(RISs)as intelligent passive auxiliary devices into indoor scenes,replacing conventional ultra-dense small cell and relay forwarding approaches to address these issues at low deployment and operation costs.Specifically,we study the optimization design of active and passive beamforming for the transmissive RISs-aided indoor multiuser downlink communication systems.This involves considering more realistic indoor congestion modeling and near-field propagation characteristics.The goal of our optimization is to minimize the total transmit power at the access point(AP)for different user service requirements,including quality-of-service(QoS)and wireless power transfer(WPT).Due to the nonconvex nature of the optimization problem,adaptive penalty coefficients are imported to solve it alternatively with closed-form solutions for both active and passive beamforming.Simulation results demonstrate that the use of transmissive RISs is indeed an efficient way to achieve flexible coverage in indoor scenarios.Furthermore,the proposed optimization algorithm has been proven to be effective and robust in achieving energy-saving transmission. 展开更多
关键词 active and passive beamforming different user requirements indoor communications NEAR-FIELD transmissive reconfigurable intelligent surface(RIS)
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Localized acidic microenvironment by Brønsted acid oxides eliminates ultrapure water requirement in PEM electrolysers
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作者 Wentao Xu Fuqin Zheng Wei Chen 《Chinese Journal of Structural Chemistry》 2025年第10期3-5,共3页
Conventional proton exchange membrane(PEM)electrolysis technology relies on ultrapure water,as cationic impurities(such as Na^(+),Ca^(2+) and Fe^(3+))can occupy H+transport sites in the membrane[1],leading to a sharp ... Conventional proton exchange membrane(PEM)electrolysis technology relies on ultrapure water,as cationic impurities(such as Na^(+),Ca^(2+) and Fe^(3+))can occupy H+transport sites in the membrane[1],leading to a sharp rise in cathode pH,catalyst deactivation,and membrane degradation[2].This forces the system to be equipped with complex water purification equipment and even necessitates the replacement of membrane electrode assemblies(MEAs),increasing the levelized cost of hydrogen(LCOH)[3].To address this,Tao Ling's group recently proposed a"local pH regulation"strategy in Nature Energy[4]. 展开更多
关键词 localized acidic microenvironment ultrapure water requirement membrane electrode assemblies meas increasing cationic impurities such conventional proton exchange membrane pem electrolysis technology proton exchange membrane electrolysis cationic impurities water purification equipment
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Sugarcane Requirement of Water and Effect of Fertigation on Sugarcane 被引量:1
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作者 谭宏伟 周柳强 +1 位作者 谢如林 黄美福 《Agricultural Science & Technology》 CAS 2009年第4期175-177,182,共4页
The sugarcane is a main sugar crop in China. The seasonal drying is one of the problems that influence the improvement of output and quality of sugarcane in China. The experimental results for the water requirement an... The sugarcane is a main sugar crop in China. The seasonal drying is one of the problems that influence the improvement of output and quality of sugarcane in China. The experimental results for the water requirement and fertigation of the sugarcane showed, that the distribution of the rainfall in spring, autumn and winter, all could not suit the requirements for sugarcane growth. Detailedly, it can suit that sugarcane requirement of 74.4%, 68.6% and 35.7% respectively at seedling emerging stage, tillering stage and mature stage according to sugarcane growth. The drought has already limited the yield of sugarcane. Application of fertigation can enhance the fertilizer use efficiency, and it is also a water saving technique in sugarcane production. 展开更多
关键词 Sugarcane planting area Distribution of rainfall Water requirement of sugarcane FERTIGATION
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Analysis of Test Methods for Parts to Follow Relative Requirements 被引量:2
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作者 潘淑清 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期71-74,共4页
Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these pr... Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these products. One of the latest subjects of study in the area of precision measurement is the testing of parts to follow the relative requirements, viz. design requirements for the size tolerance of size features and related geometrical tolerances of the central feature, including the envelope requirement, maximum material requirement and least material requirement. The article analyzes test methods for parts to follow the envelope requirement or maximum material requirement, as well as further requirements of geometrical tolerances for its central feature. The method is effective in improving product quality and rejecting unqualified parts. 展开更多
关键词 tolerancing principle envelope requirement maximum material requirement
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Classification and Comprehension of Software Requirements Using Ensemble Learning
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作者 Jalil Abbas Arshad Ahmad +4 位作者 Syed Muqsit Shaheed Rubia Fatima Sajid Shah Mohammad Elaffendi Gauhar Ali 《Computers, Materials & Continua》 SCIE EI 2024年第8期2839-2855,共17页
The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human re... The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human resources to translate these into clear functional and non-functional requirements.To address this challenge,various machine learning(ML)methods have been explored to automate the understanding of these requirements,aiming to reduce time and human effort.However,existing techniques often struggle with complex instructions and large-scale projects.In our study,we introduce an innovative approach known as the Functional and Non-functional Requirements Classifier(FNRC).By combining the traditional random forest algorithm with the Accuracy Sliding Window(ASW)technique,we develop optimal sub-ensembles that surpass the initial classifier’s accuracy while using fewer trees.Experimental results demonstrate that our FNRC methodology performs robustly across different datasets,achieving a balanced Precision of 75%on the PROMISE dataset and an impressive Recall of 85%on the CCHIT dataset.Both datasets consistently maintain an F-measure around 64%,highlighting FNRC’s ability to effectively balance precision and recall in diverse scenarios.These findings contribute to more accurate and efficient software development processes,increasing the probability of achieving successful project outcomes. 展开更多
关键词 Ensemble learning machine learning non-functional requirements requirement engineering accuracy sliding window
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Study on Chilling Requirement of Different Fruit Branch of a Sweet Cherry Cultivar ‘Hongmanao'
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作者 宋永宏 戴桂林 +4 位作者 聂国伟 李凯 田永强 石美娟 陈子润 《Agricultural Science & Technology》 CAS 2016年第10期2430-2433,共4页
With 'Hongmanao', a sweet cherry cultivar from central Shanxi Province, as the experimental material, the chilling requirements of different types of fruit branches (including mixed fruit branch, long fruit branch,... With 'Hongmanao', a sweet cherry cultivar from central Shanxi Province, as the experimental material, the chilling requirements of different types of fruit branches (including mixed fruit branch, long fruit branch, medium fruit branch, short fruit branch and blossom fruit branch) were studied by the 0-7.2 ℃ model in a solar greenhouse during 2012-2013. In the greenhouse, the fruit branches of 'Hongmanao' were cultured in water in a thermostatic environment. The results showed that the chilling requirement of leaf buds of 'Hongmanao' was lower than that of its flower buds; and the chilling requirements of the five types of fruit branches ranked as blossom fruit branch's〈short fruit branch's〈medium fruit branch's〈long fruit branch's〈mixed fruit branch's, 展开更多
关键词 'Hongmanao' Sweet Cherry Different fruit branch types Chilling requirements
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Study on the Characteristics of Ecological Water Requirement in Maijishan Scenic Spot
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作者 蒲金涌 李晓薇 《Agricultural Science & Technology》 CAS 2012年第9期1971-1976,1996,共7页
[Objective] This study aimed to explore the characteristics of ecological water requirement in Maijishan Scenic Spot. [Methed] The characteristics of ecologi- cal water requirement in Maijishan Scenic Spot were analyz... [Objective] This study aimed to explore the characteristics of ecological water requirement in Maijishan Scenic Spot. [Methed] The characteristics of ecologi- cal water requirement in Maijishan Scenic Spot were analyzed based on,the data of soil humidity and meteorology of the spot. [Result] The result showed that the actual annual ecological water requirement in the spot was 678×10^6 m^3, and the proportion of soil water and evapotranspiration were 21% and 79%, respectively; the minimum annual ecological water requirement quota in the spot was 480.27×10^6 m^3, and the proportion of soil water and evapotranspiration were 16% and 84%, respectively; the minimum annual suitable ecological water requirement quota in the spot was 624.22×10^6 m^3, and the proportion of soil water and evapotranspiration were 18% and 82%, respectively. The precipitation was 614×10^6 m^3, and consumptive water surplus reached up to 78×10^6 m^3. The years when the precipitation was higher than the evapotranspiration accounted for 76%. Since 1980s, the evapotranspiration showed a linearly increasing trend. The precipitation was higher than the evapotranspiration from Jun. to Oct. and less than the evapotranspiration from Nov. to Dec. and Jan. to May. Evapotranspiration water requirement was regulated by soil water. The dis- parity between precipitation and evapotranspiration was huge in spring, thus having certain influence on waterfalls and streams in the spot. [Conclusion] The results of this study provided a basis for the rational use and long-term planning of the water sources in Maijishan Scenic Spot. 展开更多
关键词 Maijishan Scenic Spot Ecological Water requirement CHARACTERISTICS
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On-demand QoS routing protocol based on energy and bandwidth requirement in Ad Hoc networks
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作者 石为人 黄超 雷璐宁 《仪器仪表学报》 EI CAS CSCD 北大核心 2008年第9期1793-1798,共6页
Along with the emergence of real-time multi-media,interactive service,real-time voice and other services calling for high quality of service,there should be a good network to support those services.Most present route ... Along with the emergence of real-time multi-media,interactive service,real-time voice and other services calling for high quality of service,there should be a good network to support those services.Most present route algo- rithms with computational complexity hardly consider the restriction of node energy,so it degrades the whole capabil- ity of network.Bandwidth guarantee is one of the most crucial factors in real-time application,and this paper brings forward a distributed on-demand QoS routing protocol based on energy and bandwidth requirement.This QoS routing protocol makes use of bandwidth calculation algorithm and analyzes its route mechanism.The simulation results veri- fy its validity.The QoS routing protocol improves the packet delivery fraction and average end-to-end delay,prolongs the network lifetime,enhances the network performance and satisfies the route requirement for ad hoc networks. 展开更多
关键词 通信系统 实时多媒体系统 声音 计算方法
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Professional Requirements for Contemporary Teachers
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作者 丁丽红 《海外英语》 2011年第3X期135-136,共2页
The rapid development of high-tech based information technology marks the era of a knowledge-based economy. This form of economy, characterized by knowledge, has raised new demands for most teachers. To rise to the ch... The rapid development of high-tech based information technology marks the era of a knowledge-based economy. This form of economy, characterized by knowledge, has raised new demands for most teachers. To rise to the challenge, teachers must maintain innovative attitudes and practical abilities that will meet the social requirements. The writer examines the professional requirements for contemporary teachers in this paper. 展开更多
关键词 CONTEMPORARY TEACHERS PROFESSIONAL requirements teachers’ CULTURE
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Coverage criteria and test requirement reduction for component-based web application 被引量:2
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作者 顾静娴 许蕾 徐宝文 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期36-42,共7页
In order to analyze and test the component-based web application and decide when to stop the testing process, the concept of coverage criteria and test requirement reduction approach are proposed. First, four adequacy... In order to analyze and test the component-based web application and decide when to stop the testing process, the concept of coverage criteria and test requirement reduction approach are proposed. First, four adequacy criteria are defined and subsumption relationships among them are proved. Then, a translation algorithm is presented to transfer the test model into a web application decision-to-decision graph(WADDGraph)which is used to reduce testing requirements. Finally, different sets of test requirements can be generated from WADDGraph by analyzing subsumption and equivalence relationships among edges based on different coverage criteria, and testers can select different test requirements according to different testing environments. The case study indicates that coverage criteria follow linear subsumption relationships in real web applications. Test requirements can be reduced more than 55% on average based on different coverage criteria and the size of test requirements increases with the increase in the complexity of the coverage criteria. 展开更多
关键词 web application coverage criteria test requirement reduction
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Using Artiffcial Intelligence Techniques in the Requirement Engineering Stage of Traditional SDLC Process
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作者 Afam Okonkwo Pius Onobhayedo Charles Igah 《Journal on Artificial Intelligence》 2024年第1期379-401,共23页
Artificial Intelligence,in general,and particularly Natural language Processing(NLP)has made unprecedented progress recently in many areas of life,automating and enabling a lot of activities such as speech recognition... Artificial Intelligence,in general,and particularly Natural language Processing(NLP)has made unprecedented progress recently in many areas of life,automating and enabling a lot of activities such as speech recognition,language translations,search engines,and text-generations,among others.Software engineering and Software Development Life Cycle(SDLC)is also not left out.Indeed,one of the most critical starting points of SDLC is the requirement engineering stage which,traditionally,has been dominated by business analysts.Unfortunately,these analysts have always done the job not just in a monotonous way,but also in an error-prone,tedious,and inefficient manner,thus leading to poorly crafted works with lots of requirement creep and sometimes technical debts.This work,which is the first iteration in a series,looks at how this crucial initial stage could not just be automated but also improved using the latest techniques in Artificial Intelligence and NLP.Using the popular and available PROMISE dataset,the emphasis,for this first part,is on improving requirement engineering,particularly the classification of Functional and Non-functional Requirements.Transformer-powered BERT(Bidirectional Encoder Representations from Transformers)Large Language Model(LLM)was adopted with validation performances of 0.93,0.88,and 0.88.The experimental results showed that Base-BERT LLM,its distilled counterpart,Distil-BERT,and its domain-specific version,Code-BERT,can be reliable in these tasks.We believe that our findings could encourage the adoption of LLM,such as BERT,in Requirement Engineering(RE)-related tasks like the FR/NFR classification.This kind of insight can help RE researchers as well as industry practitioners in their future work. 展开更多
关键词 NLP artiffcial intelligence soffware requirement engineering SDLC requirement classiffcation functional andnon-functional requirement large language model(LLM) BERT
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Dietary requirements of synthesizable amino acids by animals:a paradigm shift in protein nutrition 被引量:26
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作者 Guoyao Wu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2015年第1期1-12,共12页
Amino acids are building blocks for proteins in all animals. Based on growth or nitrogen balance, amino acids were traditionally classified as nutritionally essential or nonessential for mammals, birds and fish. It wa... Amino acids are building blocks for proteins in all animals. Based on growth or nitrogen balance, amino acids were traditionally classified as nutritionally essential or nonessential for mammals, birds and fish. It was assumed that all the "nutritionally nonessential amino acids (NEAA)" were synthesized sufficiently in the body to meet the needs for maximal growth and optimal health. However, careful analysis of the scientific literature reveals that over the past century there has not been compelling experimental evidence to support this assumption. NEAA (e.g., glutamine, glutamate, proline, glycine and arginine) play important roles in regulating gene expression, cell signaling, antioxidative responses, fertility, neurotransmission, and immunity. Additionally, glutamate, glutamine and aspartate are major metabolic fuels for the small intestine to maintain its digestive function and to protect the integrity of the intestinal mucosa. Thus, diets for animals must contain all NEAA to optimize their survival, growth, development, reproduction, and health. Furthermore, NEAA should be taken into consideration in revising the "ideal protein" concept that is currently used to formulate swine and poultry diets. Adequate provision of all amino acids (including NEAA) in diets enhances the efficiency of animal production. In this regard, amino acids should not be classified as nutritionally essential or nonessential in animal or human nutrition. The new Texas A&M University's optimal ratios of dietary amino acids for swine and chickens are expected to beneficially reduce dietary protein content and improve the efficiency of their nutrient utilization, growth, and production performance. 展开更多
关键词 DIET METABOLISM NUTRITION Protein requirements
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Specifying Requirements of Real-Time System with Rules and Templates 被引量:8
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作者 Wu Guo-qing Xiao Hai-feng +1 位作者 Zheng Pen Ying Shi 《Wuhan University Journal of Natural Sciences》 EI CAS 2000年第3期278-284,共7页
This paper presents a model specifying requirements of real-time systems. Different from existing researches, this model mainly uses rules and templates to represent hierarchical FSMs (Finite State Machine). In this m... This paper presents a model specifying requirements of real-time systems. Different from existing researches, this model mainly uses rules and templates to represent hierarchical FSMs (Finite State Machine). In this model, one rule corresponds to one state transition of FSM and one template corresponds to one FSM. Rules and information with respect to a FSM can be written in a template. So templates include not only state diagrams, but also information that can not be described by FSM, such as performance requirements. The specification using this model consists of a collection of templates and it is easy for users to understand and to review. After introduced the related researches and principles of the model, this paper specifies requirements of a real-time system with this model, and discusses characters of this model in the end. 展开更多
关键词 requirements specification model requirements specification real-time system finite state machine
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Dose requirement and complications of diluted and undiluted propofol for deep sedation in endoscopic retrograde cholangiopancreatography 被引量:15
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作者 Somchai Amornyotin Wichit Srikureja +1 位作者 Wiyada Chalayonnavin Siriporn Kongphlay 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2011年第3期313-318,共6页
BACKGROUND:In general,the dose requirement and complications of propofol are lower when used in the diluted form than in the undiluted form.The aim of this study was to determine the dose requirement and complications... BACKGROUND:In general,the dose requirement and complications of propofol are lower when used in the diluted form than in the undiluted form.The aim of this study was to determine the dose requirement and complications of diluted and undiluted propofol for deep sedation in endoscopic retrograde cholangiopancreatography.METHODS:Eighty-six patients were randomly assigned to either group D (diluted propofol) or U (undiluted propofol).All patients were sedated with 0.02-0.03 mg/kg midazolam (total dose ≤2 mg for age <70 years and 1 mg for age ≥70) and 0.5-1 μg/kg fentanyl (total dose ≤75 μg for age <70 and ≤50 μg for age ≥70).Patients in group U (42) were sedated with standard undiluted propofol (10 mg/mL).Patients in group D (44) were sedated with diluted propofol (5 mg/mL).All patients in both groups were monitored for the depth of sedation using the Narcotrend system.The primary outcome variable was the total dose of propofol used during the procedure.The secondary outcome variables were complications during and immediately after the procedure,and recovery time.RESULTS:All endoscopies were completed successfully.Mean propofol doses per body weight and per body weight per hour in groups D and U were 3.0 mg/kg,6.2 mg/kg per hour and 4.7 mg/kg,8.0 mg/kg per hour,respectively.The mean dose of propofol,expressed as total dose,dose/kg or dose/kg per hour and the recovery time were not significantly different between the two groups.Sedation-related adverse events during and immediately after the procedure were higher in group U (42.9%) than in group D (18.2%) (P=0.013).CONCLUSIONS:Propofol requirement and recovery time in the diluted and undiluted propofol groups were comparable.However,the sedation-related hypotension was significantly lower in the diluted group than the undiluted group. 展开更多
关键词 PROPOFOL dose requirement COMPLICATION endoscopic retrograde cholangiopancreatography
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Practical starter pig amino acid requirements in relation to immunity,gut health and growth performance 被引量:8
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作者 Bob Goodband Mike Tokach +2 位作者 Steve Dritz Joel DeRouchey Jason Woodworth 《Journal of Animal Science and Biotechnology》 SCIE CAS 2014年第3期251-261,共11页
Immune system activation begins a host of physiological responses. Infectious agents are recognized by monocytes and macrophages which in turn stimulate cytokine production. It is the hormone-like factors called cytok... Immune system activation begins a host of physiological responses. Infectious agents are recognized by monocytes and macrophages which in turn stimulate cytokine production. It is the hormone-like factors called cytokines that orchestrate the immune response. The classic responses observed with immune system activation and cytokine production include: anorexia, fever, lethargy, recruitment of other immune cells, and phagocytosis. While production of immune system components is known to require some amino acids, increases in amino acid requirements are more than offset by the associated decrease in protein accretion and increased muscle protein degradation that also accompanies immune system activation. However, the biggest impact of cytokine production is a decrease in feed intake. Therefore, as feed intake decreases, the energy needed to drive protein synthesis is also decreased. This suggests that diets should still be formulated on a similar calorie:lysine ratio as those formulated for non-immune challenged pigs. The evidence is sparse or equivocal for increasing nutrient requirements during an immune challenge. Nutritionists and swine producers should resist the pressure to alter the diet, limit feed, or add expensive feed additives during an immune challenge. While immune stimulation does not necessitate changes in diet formulation, when pigs are challenged with non-pathogenic diarrhea there are potential advantages on gut health with the increased use of crystalline amino acids rather than intact protein sources (i.e., soybean meal). This is because reducing crude protein decreases the quantity of fermentable protein entering the large intestine, which lowers post weaning diarrhea. It also lowers the requirement for expensive specialty protein sources or other protein sources such as soybean meal that present immunological challenges to the gut. The objective of this review is two-fold. The first is to discuss immunity by nutrition interactions, or lack thereof, and secondly, to review amino acid requirement estimates for nursery pigs. 展开更多
关键词 Amino acids IMMUNITY PIGS requirements
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Applying CBR to Machine Tool Product Configuration Design Oriented to Customer Requirements 被引量:12
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作者 WANG Pengjia GONG Yadong +2 位作者 XIE Hualong LIU Yongxian NEE Andrew Yehching 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第1期60-76,共17页
Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily relian... Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily reliant on the designer's experience and knowledge. To solve the problem of fuzziness and uncertainty of customer requirements in product configuration, an analysis method based on the grey rough model is presented. The customer requirements can be converted into technical characteristics effectively. In addition, an optimization decision model for product planning is established to help the enterprises select the key technical characteristics under the constraints of cost and time to serve the customer to maximal satisfaction. A new case retrieval approach that combines the self-organizing map and fuzzy similarity priority ratio method is proposed in case-based design. The self-organizing map can reduce the retrieval range and increase the retrieval efficiency, and the fuzzy similarity priority ratio method can evaluate the similarity of cases comprehensively. To ensure that the final case has the based on grey correlation analysis is proposed to evaluate similar cases best overall performance, an evaluation method of similar cases to select the most suitable case. Furthermore, a computer-aided system is developed using MATLAB GUI to assist the product configuration design. The actual example and result on an ETC series machine tool product show that the proposed method is effective, rapid and accurate in the process of product configuration. The proposed methodology provides a detailed instruction for the product configuration design oriented to customer requirements. 展开更多
关键词 customer requirements case-based reasoning machine tool case retrieval case evaluation computer-aided system
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