• Journal of Electrical Engineering and Technology
• /
• 제11권2호
• /
• pp.329-337
• /
• 2016

With the increasing deployment of distributed generators in the distribution system, a very large search space is required when dynamic programming (DP) is applied for the optimized dispatch schedules of voltage and reactive power controllers such as on-load tap changers, distributed generators, and shunt capacitors. This study proposes a new optimal voltage and reactive power scheduling method based on dynamic programming with a heuristic searching space reduction approach to reduce the computational burden. This algorithm is designed to determine optimum dispatch schedules based on power system day-ahead scheduling, with new control objectives that consider the reduction of active power losses and maintain the receiving power factor. In this work, to reduce the computational burden, an advanced voltage sensitivity index (AVSI) is adopted to reduce the number of load-flow calculations by estimating bus voltages. Moreover, the accumulated switching operation number up to the current stage is applied prior to the load-flow calculation module. The computational burden can be greatly reduced by using dynamic programming. Case studies were conducted using the IEEE 30-bus test systems and the simulation results indicate that the proposed method is more effective in terms of saving electric charges and improving the voltage profile than loss minimization.

• 기술혁신연구
• /
• 제13권2호
• /
• pp.207-222
• /
• 2005

A prerequisite for making R&D more productive is to able to measure its productivity. Most of the previous studies on this topic have attempted to measure R&D productivity at the firm or industry levels. In this study, however, R&D productivity is measured at the national level to provide R&D policy implications, particularly for Asian countries. Contrary to the previous studies where total factor productivity was adopted, this study employs the data envelopment analysis (DEA) approach to measure R&D productivity. DEA is a multi-factor productivity analysis model for measuring the relative efficiency of each Decision Making Unit (DMU). In addition to the basic DEA model that includes all inputs and outputs, five additional models are constructed by combining single input with all outputs and single output with all inputs in order to measure specialized R&D efficiency. In this study, the twenty-seven countries are classified into four clusters based on the output-specialized R&D efficiency: inventors, merchandisers, academicians, and duds. Then, the characteristics of the Asian countries with respect to R&D efficiency are identified. It is found that Singapore ranks high in total efficiency, and Japan in patent-oriented efficiency. Meanwhile, China, Korea, and Taiwan are found to be relatively inefficient in R&D. We expect that the findings from this study will be able to provide directions for R&D policy-making of the Asian countries.

• Journal of Communications and Networks
• /
• 제15권5호
• /
• pp.527-537
• /
• 2013

Improving resource utilization has been a hot issue in heterogeneous wireless networks (HWNs). This paper proposes a radio resource management (RRM) method based on access proportion optimization. By considering two or more wireless networks in overlapping regions, users in these regions must select one of the networks to access when they engage in calls. Hence, the proportion of service arrival rate that accesses each network in the overlapping region can be treated as an optimized factor for the performance analysis of HWNs. Moreover, this study considers user mobility as an important factor that affects the performance of HWNs, and it is reflected by the handoff rate. The objective of this study is to maximize the total throughput of HWNs by choosing the most appropriate factors. The total throughput of HWNs can be derived on the basis of a Markov model, which is determined by the handoff rate analysis and distribution of service arrival rate in each network. The objective problem can actually be expressed as an optimization problem. Considering the convexity of the objective function, the optimization problem can be solved using the subgradient approach. Finally, an RRM optimization scheme for HWNs is proposed. The simulation results show that the proposed scheme can effectively enhance the throughput of HWNs, i.e., improve the radio resource utilization.

• Wind and Structures
• /
• 제8권5호
• /
• pp.343-356
• /
• 2005

Overhead sign support structures number in the tens of thousands throughout the trunk-line roadways in the United States. A recent two-phase study sponsored by the National Cooperative Highway Research Program resulted in the most significant changes to the AASHTO design specifications for sign support structures to date. The driving factor for these substantial changes was fatigue related cracks and some recent failures. This paper presents the method and results of a subsequent study sponsored by the Michigan Department of Transportation (MDOT) to develop a relative performance-based procedure to rank overhead sign support structures around the United States based on a linear combination of their expected fatigue life and an approximate measure of cost. This was accomplished by coupling a random vibrations approach with six degree-of-freedom linear dynamic models for fatigue life estimation. Approximate cost was modeled as the product of the steel weight and a constructability factor. An objective function was developed and used to rank selected steel sign support structures from around the country with the goal of maximizing the objective function. Although a purely relative approach, the ranking procedure was found to be efficient and provided the decision support necessary to MDOT.

• The Journal of Asian Finance, Economics and Business
• /
• 제6권1호
• /
• pp.321-328
• /
• 2019

The purpose of the study is to analyze the main approaches to assessing human capital and develop proposals for its most objective assessment of it at the different levels of manifestation - individual, microeconomic and macroeconomic. The article considers the basic approaches to the evaluation of human capital, used in practice: retrospective (costly) and prospective (income based). Cost based methods involve measuring the value of human capital based on the total costs associated with its formation. The proposed additional evaluation criteria, in particular, the use of the expert approach and the developed indicators of a qualitative assessment of the human capital of the enterprise will allow development that is more efficient and use of available human resources. Human capital is becoming a major factor in the formation and development of an innovative economy and knowledge economy. Accordingly, the proposed additions to the assessment of human capital at the country level are aimed at assessing it from a new angle, taking into account the current global trends in the formation of an innovative economy and digitalization. They meet qualitatively new requirements for human capital as the main productive factor in the creation of new highly efficient technologies that promote the active development of the social sphere, science, education, health, etc.

• 사회복지연구
• /
• 제48권2호
• /
• pp.97-119
• /
• 2017

본 연구는 미국 자활 영역에서 아래로부터 위로의 '이용자중심(client-centered)' 접근을 통해 개발되어 사용 중인 '정서적 자활 성과 지표(Psychological Self-Sufficiency: PSS)'의 한국에의 적용 가능성을 탐색하기 위해, 한국 자활 프로그램 참여자를 대상으로 척도 타당성 검증을 실시한다. 자활사업은 전통적으로 '경제적 자활'에 초점을 두고 자활사업의 궁극적 목표인 경제적 성과에\만 집중함으로써, 자활사업 참여자의 정서적, 사회적 변화를 간과해왔다. 본 연구는 자활사업의 성과를 제고하기 위해서는 기존의 경제적 측면에서의 접근 뿐 아니라 정서적 측면에서의 접근 또한 필요함을 제안하며, 자활사업 참여자들의 정서적 변화에 초점을 둔 고용희망 척도(employment hope scale: EHS)의 타당도를 검증한다. 그 결과, 4차원 17문항으로 구성된 한국형 고용희망 척도의 타당성이 검증되었다. 본 연구는 정서적 자활 정도를 측정할 수 있는 성과지표로서 한국형 고용희망 척도의 활용가능성을 검증함으로써, 경제적 자활 성과 지표를 보완할 수 있는 보완적 과정 평가 도구로서의 적용 가능성을 제안한다.

• Genomics & Informatics
• /
• 제4권2호
• /
• pp.87-93
• /
• 2006

With the rapid development of MS technologiesy, the demands for a more sophisticated MS interpretation algorithm haves grown as well. We have developed a new protein fingerprinting method using a binomial distribution, (fBIND). With the fBIND, we improved the performance accuracy of protein fingerprinting up to the maximum 49% (more than MOWSE) and 2% than(at a previous binomial distribution approach studied by of Wool et al.) as compared to the established algorithms. Moreover, we also suggest a the statistical approach to define the significance of transcription factors and motifs in the identified proteins based on the Gene Ontology (GO). Abbreviations: fBIND, fingerprinting using binomial distribution; GO, Gene Ontology; MS, Mass Spectrometry; PMF, peptide mass fingerprinting; nr, nonredundant; SGD, Saccharomyces Genome Database

• 대한산업공학회지
• /
• 제39권1호
• /
• pp.73-77
• /
• 2013

Affective quality is considered one of the most influential factors for the competitive power of consumer products. Since the human affective response is very abstract and comprehensive, it is very difficult to understand and manipulate the Affective Quality in scientific method. This study suggested the three-level hierarchical structure of the human affection according to the human affective response process, and subdivided the Affective Quality into three subordinate concepts such as 'Organoleptic Quality', 'Affective Quality Factor' and 'Overall Affective Quality.' Also the categories of adjectives which used to express the human affections for the three levels of affective structure were suggested. The results of this study could be used as a frame of systematic approach method to the Affective Quality.

• The Journal of Asian Finance, Economics and Business
• /
• 제1권2호
• /
• pp.31-37
• /
• 2014

The portfolio selection is one of the most important and vital decisions that a real or legal person, who invests in stock market, should make. The main purpose of this article is the determination of the optimal portfolio with regard to relations among stock returns of companies which are active in Tehran's stock market. For achieving this goal, weekly statistics of company's stocks since Farvardin 1389 until Esfand 1390, has been used. For analyzing statistics and information and examination of stocks of companies which has change in returns, factors analysis approach and clustering analysis has been used (FC approach). With using multivariate analysis and with the aim of reducing the unsystematic risk, a financial portfoliois formed. At last but not least, results of choosing the optimal portfolio rather than randomly choosing a portfolio are given.

• 한국컴퓨터정보학회논문지
• /
• 제21권7호
• /
• pp.93-100
• /
• 2016

This paper shows what kind of influence the learning motivation factors have on the effectiveness of Flipped Learning Model through the case of operating a JAVA programming subject. The Flipped Learning Approach consisting of Before Class, Before or At Start of Class, and In Class provides the students with learning motivation as well as satisfies Keller's ARCS(Attention, Relevance, Confidence, Satisfaction) to keep them studying steadily. This research conducts the operation of Flipped Learning and gets Exploratory Factor Analysis and Reliability Analysis from the result of the course experience questionnaire at the end of the class. Given this survey result, Flipped Learning approach improves the learners' satisfaction in class and the effectiveness in the fields of understanding learning context more than does the previous lecture-based learning approach by pacing learning procedure and conducting self-directed learning.