• Title/Summary/Keyword: Master & Sub-Problem

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A Novel Interleaving Control Scheme for Boost Converters Operating in Critical Conduction Mode

  • Yang, Xu;Ying, Yanping;Chen, Wenjie
    • Journal of Power Electronics
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    • v.10 no.2
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    • pp.132-137
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    • 2010
  • Interleaving techniques are widely used to reduce input/output ripples and to increase the power capacity of boost converters operating in critical conduction mode. Two types of phase-shift control schemes are studied in this paper, the turn-on time shifting method and the turn-off time shifting method. It is found that although the turn-off time shifting method exhibits better performance, it suffers from sub-harmonic oscillations at high input voltages. To solve this problem, an intensive quantitative analysis of the sub-harmonic oscillation phenomenon is made in this paper. Based upon that, a novel modified turn off time shifting control scheme for interleaved boost converters operating in critical conduction mode is proposed. An important advantage of this scheme is that both the master phase and the slave phase can operate stably in critical conduction mode without any oscillations in the full input voltage range. This method is implemented with a FPGA based digital PWM control platform, and tests were carried out on a two-phase interleaved boost PFC converter prototype. Experimental results demonstrated the feasibility and performance of the proposed phase-shift control scheme.

Health Behavior Regarding Liver Flukes among Rural People in Nakhon Ratchasima, Thailand

  • Painsing, Sirinapa;Sripong, Anan;Vensontia, Orramon;Pengsaa, Prasit;Kompor, Pontip;Kootanavanichapong, Nusorn;Kaewpitoon, Soraya J;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.2111-2114
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    • 2016
  • Opisthorchiasis is a health problem in Thailand particularly in northeast and north regions where have been reported the highest of cholangiocarcinoma. Active surveillance is required, therefore a cross-sectional surveyed was conducted in Nong Bunnak sub-district of Nakhon Ratchasima province, Thailand. A total of 367 participants were selected by multistage sampling from 5 villages located near natural water resources. Participants completed a predesigned questionnaire containing behavior questions regarding liver fluke disease, covering reliability and validity knowledge (Kuder-Richardon-20) = 0.80, attitude and practice (Cronbach's alpha coefficient) = 0.82 and 0.79, respectively. Descriptive statistics included frequencies, percentages, means, and standard deviations. The majority of the participants were female (58.3%), age group between 21-30 years old (42.5%), with primary school education (59.9%), occupation in agriculture (38.1%), and married (80.9%). They had past histories of raw fish consumption (88.3%), stool examination (1.4%), anti-parasite medication used (4.6%). Heads of villages, village health volunteers, television, and village newstations were the main sources for disease information. Participants had a moderate level of behavior regarding liver fluke disease. The mean scored of knowledge regarding liver fluke life cycle, transmission, severities, treatment, prevention and control was 10.9 (SD=0.5), most of them had a moderate level, 95.1%. The mean score for attitude regarding liver fluke prevention and control was 45.7 (SD=9.7), and for practice was 30.6 (SD=10.5). Participants had a moderate level of attitude and practice, 94.5% and 47.7, respectively. This study indicates that health education is required in this community including stool examination for liver fluke as further active surveillance screening.

The Competency and Qualifications for Mid-managers in Hospitals (병원경영 전문인력에게 요구되는 역량 및 자격)

  • Chang, Hye-Jung;Kwon, Young-Dae;Sub, Kyung-Hwa
    • Korea Journal of Hospital Management
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    • v.10 no.3
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    • pp.25-44
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    • 2005
  • Despite of increasing importance of management in healthcare administration and demand for the professional managers in hospitals, there have been few studies on the issues of competencies and qualifications of mid-managers for effective role performance. This article uses hospital mid-managers' judgements to discuss them in Korean hospital settings. Based on 67 questionnaires completed through the mail survey, the data were analyzed by chi-square test, t-test, ANOVA, and logistic regression. The result shows that knowledge of management skills in healthcare field is the most necessary area in general. Specifically, 'problem-solving ability' is the most important competency, followed by communication and planning capabilities. The mid-managers tend to consider the hospital employment history more important than the academic level. They also present the willingness to recruit the candidates with bachelor degrees rather than those with master or Ph.D. degrees. It is suggested that the candidate with bachelor degree and hospital employment over 6 to 10 years is the most qualified for a mid-manager in hospitals. The study results presented in the paper will provide the direction to improve the educational program and also the insights toward a advising strategy for job consultation for students majored in health service administration.

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A Qualitative Study on the Internal Marketing of Fashion Companies in the Omni Channel Fashion Distribution Environment -Focused on the Woman's Clothing Salesperson- (옴니채널 유통환경에서 패션기업의 내부마케팅 구성요인 -여성복 판매원을 중심으로-)

  • Jungjin Lee
    • Journal of Fashion Business
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    • v.27 no.1
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    • pp.16-35
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    • 2023
  • The advent of Omni Channel has changed the fashion business model and the role of fashion sales persons. In such situation, internal marketing can become an important organizational management strategy for fashion companies. Therefore, the purpose of this study is to identify the components of internal marketing of fashion companies for fashion shop masters in an omni channel environment. To achieve the purpose of this study, To achieve the purpose of this study, a qualitative study was conducted to investigate the internal marketing sub-factors of fashion companies. In-depth interviews were conducted for qualitative study. Seven respondents to the in-depth interview were fashion shop masters who had at least 10 years of field work experience. As a result of the qualitative study, internal marketing was derived from five factors, including empowerment, education and training, rewards, internal communication, and management supports. Empowerment factors consist of initiative, encourage creativity, and problem solving. Education and training factors consist of the degree of education and training opportunities, the value of education and training, and the scope of education and training. Rewards factors consist of diversity of rewards, fairness of rewards, and source of rewards. Internal communication factors consist of communication flexibility, diversity of communication and receptivity of communication. Management support factors consist of headquarters support and department store support.

A Study on Categorization and Contents of Social Welfare Services in Rural Center Revitalization Project (농촌중심지활성화사업에서의 사회복지사업 유형 및 내용 분석)

  • JungRak Lim;Zaewoong Rhee
    • Journal of Korean Society of Rural Planning
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    • v.29 no.4
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    • pp.1-11
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    • 2023
  • In this study, we present the necessary measurements of establishment and expansion in social welfare elements, understand the social welfare approach and the reality of social welfare services to solve the physical accessibility problem of the rural center revitalization in the recent trend of various attempts. The measurements were categorized according to the nature and form of the projects through content analysis method by using a master plans and casebooks of the rural center revitalization leading districts. The results show that the social welfare project of the rural center revitalization leading districts were categorized them into three sections of job creation vitalization, lifelong education, hobby and leisure supports, visiting services, it was classified into 11 sub-types. We arrive at a conclusion through analysis results, establishment of cooperative system between related organizations, active gathering of opinions from residents, training of local workforce, convergence with existing social welfare systems and projects, building private governance, for social welfare project operate stably in the rural center revitalization.

A Meta-analysis of the Factors Related to Psychological Burn-out of Early Childhood Teachers (유아교사의 심리적소진과 관련된 요인에 대한 메타분석)

  • Moon, Dong-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.38-52
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    • 2018
  • This study examined the effect sizes of psychological burnout-related factors on the psychological burnout of early childhood teachers by applying meta - analysis focusing on master 's theses, doctoral dissertations and journals that have been published in Korea for the past 20 years. The results of the analysis are as follows. First, the total effect size, the factor group, the sub-factor, and the positive and negative effect factors of the inducing and inhibiting factors showed a significant effect size. Second, in terms of inducing factors, the task problem group showed a larger effect size than the negative relationship group. Third, among the lower factor of the negative relationship group, all the sub factors excluding the negative relationship with the director, effect size showed a medium effect size. Fourth, task stress showed the greatest effect size among the sub factors of the task factor group, followed by role conflict, task overload, and role ambiguity. Fifth, resilience showed the greatest effect size among the inhibition factors, followed by organizational support factor, teacher efficacy factor, social support factor, and emotional factor. Sixth, all sub factors of the emotional labor factor group, organizational support factor of the organizational support factor group, general teacher efficacy factor of the teacher efficacy factor group, and all sub factors of social support factor Medium effect size. In addition, the lower factor of all the other factors showed a large effect size. Seventh, of the effect factors, job satisfaction factor, depression factor, and turnover intention factor all showed a large effect size.

QoS Support in the Air Defense Alternative System (방공작전 예비체계의 QoS 지원)

  • Sim, Dong-Sub;Lee, Young-Ran;Kim, Ki-Hyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.5
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    • pp.903-909
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    • 2010
  • ADAS is the air defense control system performing air surveillance and identification of ROK and near air. This system is self-developed by Air Force, currently operated successfully as the alternative system of MCRC. ADAS processes converting and combining transferred the real time radar data detected by radars. additionally, it displays significant radar data as producing in tracks. Then, it uses the message queue for IPC(Inter Process Communication). the various tactical data processed in the server is ultimately send to the network management process through the message queue for transmitting to the weapon director console. the weapon director receives this transmitted tactical data through the console to execute air defense operations. However, there is a problem that data packet is delayed or lost since the weapon Director does not receive as the amount of tactical data from the server overflowed with air tracks and missions increased. This paper improved the algorism to display and transmit the various tactical data processed from ADAS server to numbers of the weapon director console in the real time without any delay or lost. Improved the algorism, established at exercise, the development server in the real operation network and the weapon director console, is proved by comparing the number of sending tactical data packets in the server and receiving packets in the weapon director.

A meta-analysis of the effect for Creativity, Creative Problem Solving Abilities in STEAM (융합인재교육(STEAM)의 창의성과 문제해결력 효과에 관한 메타분석 -연구방법 및 연구자를 중심으로-)

  • Lee, Seokjin;Kim, Namsook;Lee, Yoonjin;Lee, Seungjin
    • Journal of The Korean Association For Science Education
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    • v.37 no.1
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    • pp.87-101
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    • 2017
  • The analysis was carried out with meta-analysis on master's and doctoral dissertations, and academic journals that analyzed the effects of STEAM education between 2012 and 2015. From the total number of 75 dissertations and articles analyzed, 183 different effect sizes were calculated. The analysis was done to find out the kinds of differences that would be created according to the effect size of creativity, problem-solving ability, and researcher, target area, student division research design type, and level of schools. The total effect size of creativity scored 0.776, and demonstrated satisfaction in symmetry of funnel plot, with no publication biases. The fail-safe N scored 780, and since the number is smaller than 8,945, the results of this research has credibility. Furthermore, problem-solving ability shows intermediate level of effect size with a score of 0.584. It also showed satisfaction in symmetry with funnel plot, with no publication bias. With the different research methods of the sub-factors of creativity, fluency scored the highest with 0.929, flexibility with 0.881, originality with 0.838, sophistication with 0.653, abstractness with title 0.705, and resistance to termination, 0.527. This study finds its significance in the demonstration of average effect size of STEAM education through meta-analysis. According to research results, the effects of inclusive education could be determined, yet the specific effect cause or learning principles were difficult to find. It was found that the effects of STEAM education do not rise or fall depending on school age, and demonstrated differences in creativity according to the research methods or the researchers.

Research Framework for International Franchising (국제프랜차이징 연구요소 및 연구방향)

  • Kim, Ju-Young;Lim, Young-Kyun;Shim, Jae-Duck
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.4
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    • pp.61-118
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    • 2008
  • The purpose of this research is to construct research framework for international franchising based on existing literature and to identify research components in the framework. Franchise can be defined as management styles that allow franchisee use various management assets of franchisor in order to make or sell product or service. It can be divided into product distribution franchise that is designed to sell products and business format franchise that is designed for running it as business whatever its form is. International franchising can be defined as a way of internationalization of franchisor to foreign country by providing its business format or package to franchisee of host country. International franchising is growing fast for last four decades but academic research on this is quite limited. Especially in Korea, research about international franchising is carried out on by case study format with single case or empirical study format with survey based on domestic franchise theory. Therefore, this paper tries to review existing literature on international franchising research, providing research framework, and then stimulating new research on this field. International franchising research components include motives and environmental factors for decision of expanding to international franchising, entrance modes and development plan for international franchising, contracts and management strategy of international franchising, and various performance measures from different perspectives. First, motives of international franchising are fee collection from franchisee. Also it provides easier way to expanding to foreign country. The other motives including increase total sales volume, occupying better strategic position, getting quality resources, and improving efficiency. Environmental factors that facilitating international franchising encompasses economic condition, trend, and legal or political factors in host and/or home countries. In addition, control power and risk management capability of franchisor plays critical role in successful franchising contract. Final decision to enter foreign country via franchising is determined by numerous factors like history, size, growth, competitiveness, management system, bonding capability, industry characteristics of franchisor. After deciding to enter into foreign country, franchisor needs to set entrance modes of international franchising. Within contractual mode, there are master franchising and area developing franchising, licensing, direct franchising, and joint venture. Theories about entrance mode selection contain concepts of efficiency, knowledge-based approach, competence-based approach, agent theory, and governance cost. The next step after entrance decision is operation strategy. Operation strategy starts with selecting a target city and a target country for franchising. In order to finding, screening targets, franchisor needs to collect information about candidates. Critical information includes brand patent, commercial laws, regulations, market conditions, country risk, and industry analysis. After selecting a target city in target country, franchisor needs to select franchisee, in other word, partner. The first important criteria for selecting partners are financial credibility and capability, possession of real estate. And cultural similarity and knowledge about franchisor and/or home country are also recognized as critical criteria. The most important element in operating strategy is legal document between franchisor and franchisee with home and host countries. Terms and conditions in legal documents give objective information about characteristics of franchising agreement for academic research. Legal documents have definitions of terminology, territory and exclusivity, agreement of term, initial fee, continuing fees, clearing currency, and rights about sub-franchising. Also, legal documents could have terms about softer elements like training program and operation manual. And harder elements like law competent court and terms of expiration. Next element in operating strategy is about product and service. Especially for business format franchising, product/service deliverable, benefit communicators, system identifiers (architectural features), and format facilitators are listed for product/service strategic elements. Another important decision on product/service is standardization vs. customization. The rationale behind standardization is cost reduction, efficiency, consistency, image congruence, brand awareness, and competitiveness on price. Also standardization enables large scale R&D and innovative change in management style. Another element in operating strategy is control management. The simple way to control franchise contract is relying on legal terms, contractual control system. There are other control systems, administrative control system and ethical control system. Contractual control system is a coercive source of power, but franchisor usually doesn't want to use legal power since it doesn't help to build up positive relationship. Instead, self-regulation is widely used. Administrative control system uses control mechanism from ordinary work relationship. Its main component is supporting activities to franchisee and communication method. For example, franchisor provides advertising, training, manual, and delivery, then franchisee follows franchisor's direction. Another component is building franchisor's brand power. The last research element is performance factor of international franchising. Performance elements can be divided into franchisor's performance and franchisee's performance. The conceptual performance measures of franchisor are simple but not easy to obtain objectively. They are profit, sale, cost, experience, and brand power. The performance measures of franchisee are mostly about benefits of host country. They contain small business development, promotion of employment, introduction of new business model, and level up technology status. There are indirect benefits, like increase of tax, refinement of corporate citizenship, regional economic clustering, and improvement of international balance. In addition to those, host country gets socio-cultural change other than economic effects. It includes demographic change, social trend, customer value change, social communication, and social globalization. Sometimes it is called as westernization or McDonaldization of society. In addition, the paper reviews on theories that have been frequently applied to international franchising research, such as agent theory, resource-based view, transaction cost theory, organizational learning theory, and international expansion theories. Resource based theory is used in strategic decision based on resources, like decision about entrance and cooperation depending on resources of franchisee and franchisor. Transaction cost theory can be applied in determination of mutual trust or satisfaction of franchising players. Agent theory tries to explain strategic decision for reducing problem caused by utilizing agent, for example research on control system in franchising agreements. Organizational Learning theory is relatively new in franchising research. It assumes organization tries to maximize performance and learning of organization. In addition, Internalization theory advocates strategic decision of direct investment for removing inefficiency of market transaction and is applied in research on terms of contract. And oligopolistic competition theory is used to explain various entry modes for international expansion. Competency theory support strategic decision of utilizing key competitive advantage. Furthermore, research methodologies including qualitative and quantitative methodologies are suggested for more rigorous international franchising research. Quantitative research needs more real data other than survey data which is usually respondent's judgment. In order to verify theory more rigorously, research based on real data is essential. However, real quantitative data is quite hard to get. The qualitative research other than single case study is also highly recommended. Since international franchising has limited number of applications, scientific research based on grounded theory and ethnography study can be used. Scientific case study is differentiated with single case study on its data collection method and analysis method. The key concept is triangulation in measurement, logical coding and comparison. Finally, it provides overall research direction for international franchising after summarizing research trend in Korea. International franchising research in Korea has two different types, one is for studying Korean franchisor going overseas and the other is for Korean franchisee of foreign franchisor. Among research on Korean franchisor, two common patterns are observed. First of all, they usually deal with success story of one franchisor. The other common pattern is that they focus on same industry and country. Therefore, international franchise research needs to extend their focus to broader subjects with scientific research methodology as well as development of new theory.

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