• 제목/요약/키워드: Empirical relation

검색결과 803건 처리시간 0.026초

SSD 수명 관점에서 리눅스 I/O 스택에 대한 실험적 분석 (An Empirical Study on Linux I/O stack for the Lifetime of SSD Perspective)

  • 정남기;한태희
    • 전자공학회논문지
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    • 제52권9호
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    • pp.54-62
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    • 2015
  • 낸드 플래시 기반의 SSD (Solid-State Drive)는 HDD (Hard Disk Drive) 대비 월등한 성능에도 불구하고 쓰기 회수 제한이라는 태생적 단점을 가지고 있다. 이로 인해 SSD의 수명은 워크로드에 의해 결정되어 SSD의 기술 변화 추세인 SLC (Single Level Cell) 에서 MLC (Multi Level Cell) 로의 전환, MLC에서 TLC (Triple Level Cell) 로의 전환에 있어 큰 도전이 될 수 있다. 기존 연구들은 주로 wear-leveling 또는 하드웨어 아키텍처 측면에서 SSD의 수명 개선을 다루었으나, 본 논문에서는 호스트가 요청한 쓰기에 대해 SSD가 낸드플래시 메모리를 통해 처리하는 수명관점의 효율성을 대변하는 WAF (Write Amplification Factor) 관점에서 Host I/O 스택 중 파일 시스템, I/O 스케줄러, 링크 전력에 대해 JEDEC 엔터프라이즈 워크로드를 이용해 I/O 스택 최적 구성에 대해 실험적 분석을 수행하였다. WAF는 SSD의 FTL의 효율성을 측정하는 지표로 수명관점에서 가장 객관적으로 사용한다. I/O 스택에 대한 수명 관점의 최적 구성은 MinPower-Dead-XFS로 최대 성능 조합인 MaxPower-Cfq-Ext4에 비해 성능은 13% 감소하였지만 수명은 2.6 배 연장됨을 확인하였다. 이는 I/O 스택의 최적화 구성에 있어, SSD 성능 관점뿐만 아니라 수명 관점의 고려에 대한 유의미를 입증한다.

온라인 여행사 사이트 e-서비스품질이 지각된 가치, 만족도, 재구매의도에 미치는 영향 (The Intention of Repurchase on e-Service Quality by Online Travel Agency Site)

  • 우릉소;이종호
    • 산경연구논집
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    • 제9권7호
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    • pp.61-70
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    • 2018
  • Purpose - The purpose of this research is reflected on the rapid development of online tourism industries. The study was to establish the strategy for Korean tourism enterprises to develop tourist commodities suitable for Chinese tourists and attract them to visit Korea by the empirical analysis of the relation between repurchase intention of tourists and its premise variables (e-service quality, perceived value and satisfaction). Research design, data, and methodology - This research carried out a questionnaire survey on Chinese tourists who visited Korea with experience of using the online travel agency web sites. A total 398 answers were recovered, 41 of them were excluded due to the dishonest answers and 357 of them were finally analyzed. The data was analyzed with IBM SPSS AMOS 22.0. Results - The research results show that in the online travel agency web site e-service quality, convenience, interactivity, information validity, credibility had a positive impacts on perceived value and satisfaction. The perceived value of online travel agency website users has positive impart on satisfaction and repurchase intention. Satisfaction of online travel agency web site users have positive impacts on repurchase intention. But safety has no impact on perceived value while positive impacts on satisfaction was affected. Conclusions - First, in the online travel agency web site e-service quality, safety has no impact on perceived value while it was shown to have positive impacts on satisfaction because the users of online travel agency web sites believe that the protection of personal information, the defense of cracker and the safeguard of payment security are the basic premises of website operation. Although safety does not have impacts on perceived value, users benefits will suffer damage when hacker intrusion and other accidents occur so that online travel agency web sites should not ignore the security concerns. Second, credibility is a major concern for online travel agency web site users. At this time, it is necessary for the web site to establish a system to display both the commodity information and the using experience published on the user's SNS, thus improving the credibility of the website information.

개인정보 유출의 정보전이 효과 (The Effects of Information Transfer of Personal Information Security Breaches)

  • 박상수;이현철
    • 한국정보시스템학회지:정보시스템연구
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    • 제27권1호
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    • pp.193-224
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    • 2018
  • Purpose Targeting Korean companies listed on Korean securities markets (i.e., KOSPI and KOSDAQ markets), this study aims to shed lights the effects of personal information security breaches on stock prices of information security companies. Interestingly, this study is, to the best of our knowledge, the first to examine the information transfer effect on personal information security breaches of companies. Design / Methodology /Approach To examine the information transfer effect of personal information security breaches, our study employs the event study commonly used in financial studies. To this end, we investigate a variety of events of personal information security breaches of companies listed on the KOPSI stock market and the KOSDAQ market. We collect the total samples of one hundred and twelve with forty seven of events of personal information security breaches by thirty companies and sixty five of information security companies. Findings The principal findings from the empirical study are as follows. First, for companies of personal information security breaches, our event study presents the significantly negative AAR (averaged abnormal return) value on the event day at the 5 % level and the highly significant negative CAAR(cumulative averaged abnormal return) value on the event day and the day after the event day at the 1 % level. The results suggest that personal information breaches significantly contribute to an decrease in value of the information breached companies. The cross sectional regressions in this study estimate the significantly negative coefficient for the ME/BE variable, the proxy for a growth opportunity at the 5 % level. This suggests a reverse relation between the growth opportunity of companies and their value. As for the various samples of the information security companies categorized by physical security, network and system security, security application software, code authentication, system integration, we find the significantly positive AAR on the day after the event day at the 5% level, only for the network and system security-companies. This addresses that the information transfer effect followed by personal information breaches is uniquely observable for companies categorized into network and system companies. The regressions for the network and system companies estimate the significantly positive coefficient for the NS dummy variable (i.e., the dummy of the network and system security companies) at the standard level. This allows us to identify appropriate times needed to make the information transfer effect realized from personal information breached companies to information security companies.

의사결정(意思決定)의 조정(調整)과 경영지표회계(經營指標會計)에 관한 연구(硏究) (A Study On Business Indicator Accounting for Adjusting Decision)

  • 박대규
    • 산학경영연구
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    • 제3권
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    • pp.23-46
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    • 1990
  • I. Introduction: In management control, business analysis has to do with a performance evaluation and is accounted much of manager's decision making, Business indicator accounting is the vehicle of decision making and also feedback can be accomplished by it. This study is to build up a logic about what capacity for use the business indicator accounting has in making decision. Therefore it is significant to make clear the adjustment of decision and to study the function of business indicator. II. Adjustment of Decision and Accounting Work: Adjustment of decision is connected with accounting now that business indicator accounting has a function of decision making. And it should be tied up with specialization as a structure of system, organization, communication and stage system. III. Adjustment of Decision and Managerial Accounting: Managerial account makes a great contributin to the management in which each adjustment of decision should be accomplished. Let me make mention of how the adjustment of decision is accomplished concretely, and what contribution che managerial accounting makes. In an adjustment of decision, centralization and decentrialization of enterprise are very import and I think the three problems, such as the extent of sphere (procurement, production and maketing), the face of affairs (planning, implementing and controlling), the final surge (decision making and action) can be accomplished by the business indicator accounting. IV. Structure of System and Disciplinary Approach for Decision: Decision can be classified into syncronized decision and continuous decision, and is closely connected with centralization and decentralization. In the course of systematizing, the sort of decision is classified into a man in charge of decision, and object of decision, conditions of decision, and an adjusting of decision. For it's object, it has an analogical thinking and an analytic subdivision about the target area. And it is premised on getting a scientific understanding. I think a disciplinary approach remains in solving these intricate problems. V. Conclusion: In this study I dealt with a specialization as a structure in management system and a theory that adjustment is a necessary process in decision making. For an adjustment of decision, exchanging informations and communication are necessary, and accounting is in charge of the process. And then the centralization and decentralization of decision should be connected in the way of adjustment of decision. In case of decentralization, the adjustment of decision is accomplished by the exchanging informations through feedback, and in case of centralization, by the all-round planning. And also I found that syncronized decision and decentralized decision are linked together. It is natural that the function of business indicator accounting is called for to render more services for it. Therefore, according to the extent of centralization and decentralization accounting to adjust the decision, can be various. Consequently, in relation to the structure of system. I think it is necessary to make a theoretical and empirical study of the business indicator accounting.

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자동차용 연료전지 냉각계통 열관리 동적 모사 (Dynamic Modeling of Cooling System Thermal Management for Automotive PEMFC Application)

  • 한재영;이강훈;유상석
    • 대한기계학회논문집B
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    • 제36권12호
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    • pp.1185-1192
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    • 2012
  • 차량용 연료전지는 내연기관보다 운전 온도가 낮아 냉각수의 온도를 낮게 관리해야 하며, 이러한 냉각수 온도는 대기와의 온도차가 내연기관보다 작아 고성능 방열판 및 열관리계가 요구된다. 이러한 차량용 연료전지 열 관리계는 특히 연료전지 운전 온도 및 스택 내 온도분포를 결정하는 중요한 구성품이다. 본 연구에서는 차량용 연료전지 열 관리계 모델을 Matlab/$Simulink^{(R)}$ 환경 하에 개발하였으며, 기본 설계에 적용이 가능하도록 방열판 상세 모델을 개발하고 열 관리계는 팬, 모터, 방열판 그리고 냉각수 펌프로 구성하였다. 팬과 펌프는 경험식을 이용해 모델을 개발하였으며 모터 동특성을 고려하였다. 두 구성품은 연료전지의 입구와 출구 온도를 추출해 정해진 지령을 수령하도록 제어 하였다. 본 연구에는 연료전지 차량에 적합한 방열기 설계를 위해 방열기 특성을 확인하고, 이를 연료전지 시스템과 통합운전하면서, 연료전지 운전제어에 적절한 지 확인하였다.

군 조직에서 조직시민 행동이 직장-가정 갈등에 미치는 영향에 관한 연구 (A Study on The Effects of Organizational Citizenship Behavior on Work-Family Conflict)

  • 정민철;김오현
    • 한국국방경영분석학회지
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    • 제35권3호
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    • pp.119-138
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    • 2009
  • 대부분의 조직시민행동에 관한 연구가 조직유효성 측면에서 긍정적 영향을 다룬 것에 반해 본 연구는 높은 수준의 조직시민행동이 조직 구성원의 직장-가정 갈등의 수준을 높이는 부정적 영향을 초래할 수 있다는 데 초점을 맞추었다. 하지만, 이러한 가능성이 모든 조직이나 구성원들에게 보편적으로 적용될 수는 없기에 이를 관리하기 위한 조직 차원, 개인 차원의 대안을 제시하는 데 또한 목적을 두었다. 이러한 연구목적을 달성하기 위해 기존의 관련 연구를 분석하여 연구모델과 가설을 수립하고, 군인, 교사, 소방관, 은행원, 경찰관, 항공승무원 등 8개 직종의 기혼직장인 590명을 대상으로 실증분석을 실시함으로써 모델과 가설의 타당성을 검증하였다. 본 연구의 결과로 조직시민행동의 부정적 영향 즉, 높은 조직시민행동을 보이는 직장인일수록 직장-가정 갈등을 높게 지각하는 것을 확인하였다. 또한, 개인의 SOC 전략이 높을수록, 조직의 가족 친화적 분위기에 대한 지각이 높을수록 이러한 부정적 영향이 덜 나타난다는 것을 알 수 있었다.

체인 패밀리 레스토랑의 고객 만족 및 고객 충성도에 미치는 요인 분석 (Analysis of the Factors Affecting Customer Satisfaction and Customer Loyalty in a Family Restaurant Chain)

  • 김순홍;유병국
    • 유통과학연구
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    • 제13권5호
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    • pp.103-111
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    • 2015
  • Purpose - When it comes to first impressions of family restaurants, people basically think of the following factors: cozy, a refreshing space, indoor lighting, atmospheric music, the best-quality service through mutual interactions with employees, birthday events, follow-up customer management, brand image, and many others. Focusing on such family restaurants characteristics, with consumption experience and customer satisfaction determined as mediator variables, this study looks into the selection factors that affect customer loyalty when choosing a family restaurant. Subsequently, the study conducts an empirical analysis of these selection factors with the greatest influence. Research design, data, and methodology - This study analyzed 200 total surveys of family restaurant customers including college students, workers, housewives, and others. The survey was conducted over two weeks in May 2014. For statistical processing, SPSS 21 was used for factor analysis and reliability analysis as well as AMOS for structural equation analysis. In terms of a variable that would influence either consumption experience or customer satisfaction at the restaurants, the study introduced the concept of customer equity. The study designed a model based on a hypothesis developed using the following factors: customer encounter service value, customer convenience value, brand equity, relationship equity, and other factors defined as components of customer equity by Rust et al. (2000) determined as independent variables as well as with customer experience and customer satisfaction set as mediator variables. The hypothesis, after all, assumed that customer loyalty would be positively (+) influenced. Results - The analysis results from the study reported that brand value, customer encounter service value, and relationship value have positive (+) effects on consumption experience and customer satisfaction. However, as for customer convenience value, this turned out not to have a statistically significant influence on consumption experience and customer satisfaction. In regard to a relation between consumption experience and customer satisfaction, the results showed that the former affects the latter, and in terms of intervening variables, both of these appeared to have a positive (+) effect on customer loyalty. Conclusions - This study suggests that family restaurants should look for strategies that focus on how to promote customer relationships. For example, restaurants could try birthday events or discount events to achieve this goal. Since the study ended up realizing relatively low levels of suitability and statistical significance, the path of the study changed. After all, in order to increase suitability and statistical significance, the study had to eliminate factors such as service quality and others and for this reason the study was unable to conduct the analysis as initially planned. In addition, the data samples of the research were mainly gathered from students, which made it hard to say that the analysis was carried out on samples from every different group. Future research should analyze the characteristics of each group of customers for factors affecting customer satisfaction and customer loyalty in the family restaurant chain.

모바일 관광정보 서비스특성이 지각된 가치 만족도 및 이용의도에 미치는 영향 연구 (The Effect of Mobile Tourism Information Service Features on Perceived Value, Satisfaction, and Using Intentions)

  • 이성준;대정
    • 유통과학연구
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    • 제12권12호
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    • pp.75-82
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    • 2014
  • Purpose - Due to the rapidly changing environment, the needs of information distribution are emphasized more than ever before. As information changes to cater to diversity, professionalism, and detailed segmentation, this information is produced exponentially. Many researchers working in intelligence agencies are feeling the need to establish a comprehensive information management and information distribution system in a systematic and more effective manner. Mobile marketing is based on communication when consumers can access information using GPS systems whatever their location may be when they are on a trip. Until recently, Korean companies have been struggling to perform well in the larger mobile tourism information service (MTIS) for Chinese tourists, which is regarded as a blue ocean area. The principal dimensions of the characteristics of a mobile tourism information service were analyzed, and the influence on perceived value and satisfaction was identified. Moreover, the relationship among the variable satisfaction and using intentions was empirically analyzed. Research design, data, and methodology - This study examined the structural relationship among mobile tourism information features, perceived value, satisfaction, and behavioral intentions. It is based on analyzed data from questionnaires involving advanced research. A questionnaire survey targeting Chinese students using a mobile tourism information service in Korea was conducted. A total of 230 questionnaires were circulated, and 221 questionnaires were used for empirical analysis, excluding invalid data. The data were analyzed with structural equation modeling with SPSS 21.0 statistic package reliability analysis, factor analysis, and regression analysis were implemented, and the effects of the mobile tourism information service features on perceived value, satisfaction, and using intentions were presented. Results - First, mobile tourism information service features have a direct positive effect on the practical value, and do not affect the hedonic value. Second, perceived value has a statistically positive effect on satisfaction. Third, perceived value has a positive effect on behavioral intentions. Fourth, satisfaction has a direct positive effect on behavioral intentions. Conclusion - MTIS (mobile tourism information service) involves personal, social, and technical characteristics. We have analyzed the effects of mobile tourism information service on perceived value, and on satisfaction and using intentions. First, the study shows that the characteristics of mobile tourism information service and perceived value in relation to mobile tourism information service usage are important for marketing in the Chinese market. Moreover, after using a mobile tourism information service, the effect on practical value is more than on hedonic value. We could not analyze the program for tourism information service extensively, and used only questionnaires from Chinese students in Korea. In the future, there should be research on the programs for a tourism information service. We expect to study the MTIS program in greater detail, and to improve the quality and reputation of MTIS through the analysis of its program. We hope that this research will allow an evaluation of the relationship between Korea and China regarding MTIS.

수요·공급자를 통합한 u-서비스 우선순위 평가모형 개발 (Development of U-Service Priority Model Based on Customer and Provider's View)

  • 장재호;엄정섭
    • 한국지리정보학회지
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    • 제11권2호
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    • pp.132-147
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    • 2008
  • 유비쿼터스 서비스(u-서비스) 우선순위 평가에 대한 선행연구는 공급자에 주안점을 두고 있어 결과의 타당성에서 한계를 노출하고 있다. 특히 지금까지 중앙부처 및 지방자치단체에서 제시하고 있는 대부분의 유비쿼터스 추진사업은 u-서비스 사업 우선순위가 정책담당자의 경험이나 직관, 또는 소수전문가들의 경험적 지식 등에 의존하여 선정되고 있다. 이러한 한계를 극복하기위해 u-서비스 공급자 측면과 수요자 측면의 요구를 모두 충족할 수 있는 u-서비스 우선순위 평가모형을 개발하고자 본 연구가 수행되었다. u-서비스 우선순위 모형개발을 위해 선행 연구를 토대로 수요자와 공급자의 서비스 결정요인을 탐색적으로 도출하고, 전문가와의 브레인스토밍을 통해 u-서비스 결정의 확정적 요인을 추출하였다. 도출된 요인들을 계층분석(AHP)모형으로 설정하고 전문가 설문조사를 통해 요인별 가중치와 우선순위를 도출하여 u-지역정보화에서 제시한 대구지역의 특화서비스를 평가하였다. 평가 결과 대구지역은 지역물류지원서비스, 시각장애인 길안내 서비스, u-텔레매틱스 서비스가 상위권을 차지한 반면, u-지역정보화에서 제시한 안전방재지원서비스와 산업특화거리 등의 서비스는 중위권을 차지하고 있어 공급자 위주의 u-서비스 선정결과와는 차별성을 보였다.

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한국의 경제성장과 전력수요간의 인과성에 관한 연구: 분기별 자료를 이용하여 (Investigation on Granger Causality between Economic Growth and Demand for Electricity in Korea: Using Quarterly Data)

  • 백문영;김우환
    • 응용통계연구
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    • 제25권1호
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    • pp.89-99
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    • 2012
  • 본 연구는 한국의 경제성장과 전력수요 사이의 Granger-인과성을 조사한 것이다. 실증분석을 위해 1970년 1분기부터 2009년 4분기까지의 분기별 실질 GDP와 전력소비 시계열 자료를 활용하였다. 두 시계열에 단위근이 존재하고 공적분 관계가 있음을 확인한 후 오차수정모형을 구성하였으며, Hsiao (1979)의 순차적 모형식별 과정을 적용해서 자기회귀항의 최적시차를 결정하여 모형을 추정하였다. Hsiao 방식의 Granger-인과성 분석결과, 한국의 경제성장과 전력수요는 양방향의 인과관계를 보였다. 추정된 개별 오차수정모형을 기반으로 Engle-Granger 방식의 추가적인 인과성 분석 결과로부터는 (1) 경제성장과 전력수요 사이의 단기적인 양방향성 인과관계, (2) 양방향성 강 인과관계, 그리고 (3) 장기적으로는 전력수요로부터 경제성장으로의 단방향성 인과관계를 확인할 수 있었다. 이러한 결과는 기존의 선행연구의 결과와는 상반되는 것이나, 지속적인 경제성장을 추구하는 한국의 상황에서 더 의미 있는 정책적 시사점을 줄 수 있다.