• Title/Summary/Keyword: Service Performances

검색결과 497건 처리시간 0.02초

염해 실태조사를 통한 철근 콘크리트 교각의 내구수명 평가 - 결정론적 및 확률론적 해석방법 (Evaluation of Service Life in RC Column under Chloride Attack through Field Investigation: Deterministic and Probabilistic Approaches)

  • 권성준
    • 한국구조물진단유지관리공학회 논문집
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    • 제19권5호
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    • pp.67-74
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    • 2015
  • 콘크리트 구조물은 경제적이고 내구적인 구조물이지만 철근부식에 따라 성능이 내구적, 구조적 저하하게 된다. 최근들어 내구성설계가 도입되고 있는데, 콘크리트 구조물의 내구수명은 해수에 같이 노출되더라도, 국부적인 노출환경과 설계방법에 따라 다르게 평가된다. 본 연구는 3.5년~4.5년 해수에 노출된 4개의 RC 교각을 대상으로 실태조사를 수행하여 25개의 콘크리트 코어를 채취하였으며, 전염화물을 평가하여 표면염화물량 및 겉보기 확산계수를 도출하였다. Fick's $2^{nd}$ Law를 기본으로 한 결정론적 방법과 임계확률을 고려한 확률론적인 방법을 수행하여 내구수명을 각각 평가하고 분석하였다. 확률론적인 방법은 보수적으로 평가되었으며, 같은 구조물이라 하더라도 간만대 및 40.0 m 이상의 비말대에서는 비교적 낮은 내구수명이 평가되었다. 본 연구에서는 코어채취높이에 따른 염화물 거동 분석과 내구성 설계방법의 현시점에서의 한계성이 분석되었다.

공공기관 고객만족지수(PCSI) 모형을 적용한 도서관 고객만족도 측정 (Measuring Library User Satisfaction using the Public-service Customer Satisfaction Index (PCSI))

  • 권나현;표순희;이정연
    • 한국문헌정보학회지
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    • 제52권1호
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    • pp.313-340
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    • 2018
  • 본 연구는 우리나라 공공기관 고객만족 조사에 보편적으로 활용되고 있는 "공공기관 고객만족지수(Public-service Customer Satisfaction Index, PCSI)모형"을 도서관에 적용하여 측정함으로써 고객만족 결과를 조직의 성과평가에 활용할 수 있는 기반을 마련하고자 하였다. 이를 위해 국회도서관을 대상으로 하여 PCSI 기반의 고객만족도 조사 모형을 설계하고 국회도서관 이용자 341명으로부터 수집한 설문조사를 통해 모형을 검증하였다. 분석 결과, 국회도서관이 이용자에게 제공하는 각종 서비스의 품질은 고객만족의 원인이 되고, 고객만족은 또 조직성과에 직접적으로 영향을 미치고 있으며 서비스의 환경품질과 사회품질요인이 고객만족도에 긍정적인 영향을 주는 것으로 파악되었다. 또한 선행요인모형, 만족모형, 성과모형 모든 영역에서 외부이용자가 내부이용자에 비해 높은 점수를 보였고 PCSI의 고객만족모형을 통해 산출된 고객만족 점수는 80.4로 나타났다. 본 연구는 고객만족을 통해 조직의 성과를 측정하는 이론적 체계를 확보하는 동시에, 이용자 관점에서 성과목표 달성 정도를 측정하는 성과관리 도구로 활용할 수 있다.

혼합 패치를 이용한 Ku 대역 위성통신용 광대역 배열 안테나 설계 (Wideband Array Antenna Design for Ku-Band Satellite Communications Using Mixed Patches)

  • 김성훈;고지환
    • 한국항행학회논문지
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    • 제27권3호
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    • pp.281-286
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    • 2023
  • 본 논문은 고정위성업무(FSS; Fixed-Satellite Service) 및 방송위성업무(BSS; Broadcasting-Satellite Service)의 다운링크 대역을 통합하는 Ku 대역의 위성통신용 광대역 혼합 패치 배열 안테나의 설계에 관한 것으로써, 제안한 안테나는 FR4 기판 상에 사각 패치를 6 x 2 형태로 배열하여 구현되었다. FSS 다운링크 대역(10.7~10.95 GHz, 11.2~11.45 GHz) 및 BSS 다운링크 대역(11.7~12.5 GHz, 12.2~12.75 GHz, 11.7~12.2 GHz)을 모두 포함하는 광대역(10.7~12.75 GHz) 안테나를 설계하기 위해 11.5 GHz 및 12.5 GHz에서 동작하는 사각 패치를 각각 교대로 배열하였고 이를 통해 중심주파수의 30.8%에 해당하는 광대역을 확보하였다. 안테나의 성능을 확인하기 위해 제안한 안테나를 제작 및 측정하였고 모의시험 결과와 유사함을 확인하였으며 따라서 제안된 안테나는 FSS 및 BSS 다운링크를 위한 안테나로 적용이 가능하다.

클라우드 컴퓨팅 서비스의 도입특성이 조직의 성과기대 및 사용의도에 미치는 영향에 관한 연구: 혁신확산 이론 관점 (A Study on the Effect of the Introduction Characteristics of Cloud Computing Services on the Performance Expectancy and the Intention to Use: From the Perspective of the Innovation Diffusion Theory)

  • 임재수;오재인
    • Asia pacific journal of information systems
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    • 제22권3호
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    • pp.99-124
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    • 2012
  • Our society has long been talking about necessity for innovation. Since companies in particular need to carry out business innovation in their overall processes, they have attempted to apply many innovation factors on sites and become to pay more attention to their innovation. In order to achieve this goal, companies has applied various information technologies (IT) on sites as a means of innovation, and consequently IT have been greatly developed. It is natural for the field of IT to have faced another revolution which is called cloud computing, which is expected to result in innovative changes in software application via the Internet, data storing, the use of devices, and their operations. As a vehicle of innovation, cloud computing is expected to lead the changes and advancement of our society and the business world. Although many scholars have researched on a variety of topics regarding the innovation via IT, few studies have dealt with the issue of could computing as IT. Thus, the purpose of this paper is to set the variables of innovation attributes based on the previous articles as the characteristic variables and clarify how these variables affect "Performance Expectancy" of companies and the intention of using cloud computing. The result from the analysis of data collected in this study is as follows. The study utilized a research model developed on the innovation diffusion theory to identify influences on the adaptation and spreading IT for cloud computing services. Second, this study summarized the characteristics of cloud computing services as a new concept that introduces innovation at its early stage of adaptation for companies. Third, a theoretical model is provided that relates to the future innovation by suggesting variables for innovation characteristics to adopt cloud computing services. Finally, this study identified the factors affecting expectation and the intention to use the cloud computing service for the companies that consider adopting the cloud computing service. As the parameter and dependent variable respectively, the study deploys the independent variables that are aligned with the characteristics of the cloud computing services based on the innovation diffusion model, and utilizes the expectation for performance and Intention to Use based on the UTAUT theory. Independent variables for the research model include Relative Advantage, Complexity, Compatibility, Cost Saving, Trialability, and Observability. In addition, 'Acceptance for Adaptation' is applied as an adjustment variable to verify the influences on the expected performances from the cloud computing service. The validity of the research model was secured by performing factor analysis and reliability analysis. After confirmatory factor analysis is conducted using AMOS 7.0, the 20 hypotheses are verified through the analysis of the structural equation model, accepting 12 hypotheses among 20. For example, Relative Advantage turned out to have the positive effect both on Individual Performance and on Strategic Performance from the verification of hypothesis, while it showed meaningful correlation to affect Intention to Use directly. This indicates that many articles on the diffusion related Relative Advantage as the most important factor to predict the rate to accept innovation. From the viewpoint of the influence on Performance Expectancy among Compatibility and Cost Saving, Compatibility has the positive effect on both Individual Performance and on Strategic Performance, while it showed meaningful correlation with Intention to Use. However, the topic of the cloud computing service has become a strategic issue for adoption in companies, Cost Saving turns out to affect Individual Performance without a significant influence on Intention to Use. This indicates that companies expect practical performances such as time and cost saving and financial improvements through the adoption of the cloud computing service in the environment of the budget squeezing from the global economic crisis from 2008. Likewise, this positively affects the strategic performance in companies. In terms of effects, Trialability is proved to give no effects on Performance Expectancy. This indicates that the participants of the survey are willing to afford the risk from the high uncertainty caused by innovation, because they positively pursue information about new ideas as innovators and early adopter. In addition, they believe it is unnecessary to test the cloud computing service before the adoption, because there are various types of the cloud computing service. However, Observability positively affected both Individual Performance and Strategic Performance. It also showed meaningful correlation with Intention to Use. From the analysis of the direct effects on Intention to Use by innovative characteristics for the cloud computing service except the parameters, the innovative characteristics for the cloud computing service showed the positive influence on Relative Advantage, Compatibility and Observability while Complexity, Cost saving and the likelihood for the attempt did not affect Intention to Use. While the practical verification that was believed to be the most important factor on Performance Expectancy by characteristics for cloud computing service, Relative Advantage, Compatibility and Observability showed significant correlation with the various causes and effect analysis. Cost Saving showed a significant relation with Strategic Performance in companies, which indicates that the cost to build and operate IT is the burden of the management. Thus, the cloud computing service reflected the expectation as an alternative to reduce the investment and operational cost for IT infrastructure due to the recent economic crisis. The cloud computing service is not pervasive in the business world, but it is rapidly spreading all over the world, because of its inherited merits and benefits. Moreover, results of this research regarding the diffusion innovation are more or less different from those of the existing articles. This seems to be caused by the fact that the cloud computing service has a strong innovative factor that results in a new paradigm shift while most IT that are based on the theory of innovation diffusion are limited to companies and organizations. In addition, the participants in this study are believed to play an important role as innovators and early adapters to introduce the cloud computing service and to have competency to afford higher uncertainty for innovation. In conclusion, the introduction of the cloud computing service is a critical issue in the business world.

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A Cross-layer Link Adaptive HD Video Transmission Scheme in WiMedia D-MAC based UWB Systems

  • Joo, Yang-Ick
    • 한국멀티미디어학회논문지
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    • 제15권12호
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    • pp.1464-1474
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    • 2012
  • In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

재난안전 통신망 서비스를 위한 대수 주기 다이폴 배열 안테나의 소형화 (Miniaturization of Log-Periodic Dipole Array Antenna for PS-LTE Service)

  • 전후동;허수영;고지환
    • 한국전자파학회논문지
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    • 제28권3호
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    • pp.170-176
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    • 2017
  • 본 논문에서는 재난안전 통신망(Public Safety LTE: 698~806 MHz) 서비스를 위하여 대수 주기 다이폴 배열(Log-Periodic Dipole Array) 안테나의 소형화 구조를 제안하였다. LPDA 안테나를 소형화하기 위하여 배열 다이폴에 반복성 프랙털 나무(fractal tree) 소자를 새롭게 추가하여 배열 다이폴의 길이를 단축하였다. 그 결과, 전형적인 LPDA 안테나와 비교하여 약 25 % 정도 소형화 되었다. 제안한 LPDA 안테나 설계 규격을 검증하기 위하여 두께가 1.5 mm인 알루미늄을 사용하여 실제 제작 및 성능을 측정하였으며, 계산 결과와 비교적 양호한 결과를 얻었다.

순방향 WCDMA 채널에서 AMR 음성 코덱 모드 할당방식에 대한 성능 비교 (Performance Comparison of AMR Codec Mode Allocations in Downlink WCDMA System)

  • 정성환;홍정완;이상천;이창훈
    • 대한산업공학회지
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    • 제31권4호
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    • pp.349-357
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    • 2005
  • The Adaptive Multi-Rate (AMR) speech codec is the mandatory for voice service in WCDMA systems. The AMR codec can be used efficiently to provide a balanced trade-off between the capacity and quality of voice by adjusting various service rates. In this paper, three ways of AMR mode allocation schemes on the downlink in WCDMA system are evaluated. To evaluate users satisfaction efficiently, new system performance measure and analytic models are proposed. The proposed analytic models can be applied to obtain optimal mode allocation ways while considering the system capacity and quality of voice. In numerical examples, the ways of finding optimal parameters are illustrated for the given traffic loads and the performances of three mode allocation schemes are compared.

Seamless N-스크린 서비스를 위한 WiMedia D-MAC에서의 효율적인 멀티캐스트 전송 기술 (Efficient Multicast Transmission Scheme in WiMedia D-MAC for Seamless N-Screen Services)

  • 허경
    • 한국정보통신학회논문지
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    • 제19권4호
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    • pp.813-818
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    • 2015
  • 논문에서는 Seamless N-스크린 서비스를 위한 무선 통신 MAC 구조로서, WiMedia Distributed-MAC 프로토콜을 적용하고, Seamless D-MAC 프로토콜에서 P2P 스트리밍이 가능한 OSMU (One Source Multi Use) N-스크린 서비스를 제공하기 위해, Multicast-free DRP Availability IE 기술을 제안하고 성능을 분석하였다. 이를 위해 Multicast DRP Owner와 Receiver를 구분하였다. 시뮬레이션 결과를 통해 제안하는 멀티캐스트 기술은 멀티캐스트 전송 시 요구되지 않는 ACK 전송 특성을 이용하여, 무선 N-스크린 전송을 위한 멀티캐스트 및 유니캐스트 전송 DRP 예약 구간을 확장하고 수율을 향상시키는 효과를 나타내었다.

비용 제약 하에서 서비스 수준을 최대화화는 설비입지선정에 관한 연구 (The Maximal Covering Location Problem with Cost Restrictions)

  • 홍성학;이영훈
    • 대한산업공학회지
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    • 제30권2호
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    • pp.93-106
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    • 2004
  • This paper studied a maximal covering location problem with cost restrictions, to maximize level of service within predetermined cost. It is assumed that all demand have to be met. If the demand node is located within a given range, then its demand is assumed to be covered, but if it is not, then its demand is assumed to be uncovered. An uncovered demand is received a service but at an unsatisfactory level. The objective function is to maximize the sum of covered demand, Two heuristics based on the Lagrangean relaxation of allocation and decoupling are presented and tested. Upper bounds are found through a subgradient optimization and lower bounds are by a cutting algorithm suggested in this paper. The cutting algorithm enables the Lagrangean relaxation to be proceeded continually by allowing infeasible solution temporarily when the feasible solution is not easy to find through iterations. The performances are evaluated through computational experiments. It is shown that both heuristics are able to find the optimal solution in a relatively short computational time for the most instances, and that decoupling relaxation outperformed allocation relaxation.

맘퀴스트 생산성지수를 활용한 강원도 보건소의 생산성 변화 분석(2006-2013) (Analysis of the Productivity Trend of Public Health Centers in Gangwon-do Using the Malmquist Productivity Index(2006-2013))

  • 엄태림;민하주;이광수
    • 보건의료산업학회지
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    • 제10권2호
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    • pp.15-23
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    • 2016
  • Objectives : The purpose of this study was to evaluate the productivity changes of 18 public health centers in Gangwon-do from 2006 to 2013 using the Malmquist Productivity Index(MPI). Methods : Data were collected from Statistics Korea from 2006 to 2013. The input variables were the numbers of medical, nursing and administrative personnels. The output variables were the performances of health promotion programs. Along with the traditional input-oriented DEA analysis, the MPI was calculated. Results : First, among the 18 public health centers, the productivity index of 14 public health centers was increased. Second, the annual productivity showed a 6% increase. Third, the productivity improvements were mainly caused by Scale Efficiency Change. Conclusions : Improving the productivity of public health centers requires the support and external policies of the national and local government. Internally, public health centers need to maintain scale optimization of the center. Additionally, efforts should be made to effectively use limited resources.