• Asia Marketing Journal
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• v.6 no.1
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• pp.1-16
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• 2004

서비스품질의 차원과 위계에 대한 논의가 최근 들어 늘어나고 있다. 그 이유는 서비스품질, 고객만족, 고객의 긍정적 행동의향, 수익성 간의 선순환 때문이다. 차원모델은 SERVQUAL과 SERVPERF 모델이 있고 위계모델은 Grönroos(1984)모델과 미국학자들이 개발한 모델이 대표적이다. 최근들어 이들을 결합한 하이브리드모델이 제안되고 있다. 하지만 기존의 하이브리드모델은 차원과 위계를 결합하여 일반성은 높지만 위계를 정하는 이론적 근거가 분명하지 않다. 본 연구는 욕구위계이론 중 Herzberg(1968)의 두 요인이론에 근거하여 서비스품질의 위계모델을 제시하려 한다. 이를 위해 CIT로 판매접점에서 고객이 느끼는 결정적 사건(critical incidents)을 조사하였다. 먼저 중복요인과 단독요인으로 나누고 각각을 다시 불만족중심과 만족중심으로 나눌 때 이들 결정적 사건이 잘 분류되었다. 분류결과 신뢰성은 불만족중심 중복요인, 응답성은 만족중심 중복요인, 공감성은 단독만족요인으로 나타났다. 본 연구에서 제시하는 서비스품질의 욕구위계모델에 따르면 신뢰성, 응답성, 공감성의 순으로 서비스품질이 중요하다. 확신성과 유형성은 따로 분류되는 결정적 사건이 없어 만족, 불만족 요인을 도와주는 조절요인으로 볼 수 있다.

• Journal of The Korean Association of Information Education
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• v.13 no.1
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• pp.96-104
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• 2009

We want to achieve the reliable information system such as e learning system in the internet environments. The difficulty of the program reliability estimation comes from faults that occurred from program and data files are distributed among several servers. This paper is focus on a modeling approach based on Colored Petri Nets to estimate the program reliability in an internet environment. The procedure of analyzing the reliability is as follows. At first, we propose an internet program model. This model is transformed into a Colored Petri net, and the reliability is estimated. We adapt this model to the analyzing the reliability in the internet environment. This method is very simple, and is very helpful to develope program

• Journal of Korean Society of Steel Construction
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• v.14 no.5 s.60
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• pp.627-639
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• 2002

Bridge construction is almost complete in many countries. Thus, the government and highway agencies change their focus from constructing to maintaining. Effectively maintaining bridges require predicting their lifespan using a system reliability viewpoint. Likewise, maintenance models based on the system reliability concept should be developed. Thus, this study developed maintenance models for preventive maintenance and essential maintenance using system reliability and lifetime distributions. The optimal maintenance strategy for an existing bridge was obtained using the developed maintenance models.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2343-2349
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• 1999

The hyper-geometric distribution software reliability growth model (HGDM) was recently developed and successfully applied to real data sets. The HGDM considers the sensitivity factor as a parameter to be estimated. In order to reflect the random behavior of the test-and-debug process, this paper generalizes the HGDM by assuming that the sensitivity factor is a binomial random variable. Such a generalization enables us to easily understand the statistical characteristics of the HGDM. It is shown that the least squares method produces the identical results for both the HGDM and the generalized HGDM. Methods for computing the maximum likelihood estimates and predicting the future outcomes are also presented.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.540-556
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• 2009

The hub and spoke network is a critical network-based infrastructure that is widely applied in current transportation and telecommunications systems, including Internets, air transportation networks and highway systems. This main idea of hub location models is to construct a network system which achieves the economy of scale of flows. The main purpose of this study is to introduce new hub location problems that take into account network reliability. Two standard models based on assignment schemes are proposed, and a minimum threshold model is provided as an extension in terms of hub network design. The reliability and interaction potentials of 15 nodes in the U.S. are used to examine model behaviors. According to the type of models and reliability, hubs, and minimum threshold levels, relationships among the flow economy of scale, network costs, and network resiliency are analyzed.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.364-366
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• 2003

수준 높은 소프트웨어의 품질과 개발, 유지보수 비용의 최소화, 제품 출하시간의 단축을 위하여 소프트웨어 프로세스에 대한 예측, 통제 가능성을 증가시키기 위함이다. 기업이 최고도의 높은 수준에 도달하기 의해서는 정량적인 모델에 의한 프로젝트 관리가 필요하다. 따라서 기업들은 SPICE/CMM와 같은 표준을 사용하여 조직의 프로세스 능력 수준을 평가하고 수준향상을 꾀한다. 조직의 프로세스의 능력을 평가하고 수준향상을 위해서는 신뢰성 있는 SPICE 심사의 심사결과에 대한 객관적인 신뢰성의 보장과 좀더 적은 비용으로 프로세스의 수준향상을 할 수 있는 방법이 필요하다. 본 논문에서는 SPICE 심사의 신뢰성을 얻기 위해 CMM/KPA 설문서를 통해 심사하고 SPICE심사의 결과를 비교 분석하여 SPICE심사의 신뢰성을 검증한다. 또한 이를 기반으로 CMM/KPA 설문서의 정량적인 모델을 제안함으로서 좀더 적은 비용과 시간으로 SPICE 심사의 결과와 같은 효과를 얻을 수 있게 한다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.7
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• pp.500-504
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• 2009

A reliability of software is a type of nonfunctional requirement. Traditionally, a validation of the reliability is processed at the integration phase in software development life cycle. However, it increases the cost and the risk for the development. In this paper, we propose reliability analysis method based on mathematical analytic model at the architecture design phase of the development process as follows. First, we propose the software modeling methodology for reliability analysis using Hierarchical combined Queueing Petri Nets(HQPN). Second, we derive the Markov Reward Model from the HQPN based model. We apply our approach to the video conference system to verify the usefulness of our approach. Our approach supports quantitative evaluation of the reliability.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.108-110
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• 2020

본 연구의 목적은 딥러닝 기법의 하나인 인공신경망 모델을 활용하여 선박의 가치평가 모델을 개발하는 것이다. 선박의 가치는 해운시장 변화와 밀접한 관계가 있으며, 경기 변동성이 크고 시장 민감성이 높은 해운시장의 특성상 가치의 불확실성 역시 높게 나타나고 있다. 이러한 선박가치의 중요성에도 불구하고 국내외적으로 선박가치평가의 체계 개선 및 평가모델의 객관성과 신뢰성을 제고시키기 위한 연구는 부족한 실정이다. 따라서 본 연구에서는 딥러닝 방법을 통해 선박의 가치를 산출하는 새로운 평가모델을 제시하고자 한다. 가치평가의 대상은 중고 VLCC선이며, 선행연구를 통해 선박의 가치 변화를 유발하는 주요 요인들을 선별하여 변수를 설정하고 2010년 1월부터 현재까지의 해당 데이터를 확보하였다. 교차검증을 통해 파라미터들을 추정하여 인공신경망의 최적 구조를 식별하고 이에 대한 객관성과 신뢰성을 검증한 결과 인공신경망 모델의 가치평가 정확성이 우수함을 확인하였다. 본 연구는 선박가치평가의 전통적 방법론에서 탈피하여 기계학습 기반의 딥러닝 모델을 활용한 측면에서 독창적인 의미가 있다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.5
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• pp.507-512
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• 2011

This study is concerned with the reliability analysis and its based design of midship section against the ultimate bending strength. Eight bulk carriers and seven oil tankers over 100m length are chosen for the present study. Target reliability indices for the two ship types have been derived based on the results reliability analysis of the present ship models. Reliability-based structural design codes are proposed for use in design of midship section of bulk carriers and oil tankers. The design codes proposed in this study have been successfully applied to re-design of midship section of the present ship types. It has been found that the proposed codes can provide more uniform structural design results.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.11-20
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• 2024

In the recent era of NewSpace, unlike high-reliability satellites of the past, low-reliability satellites are being developed and mass-produced at a lower cost to launch constellations satellites. To achieve cost-effective cluster satellite development, satellite users and developers need to assess the feasibility of maintaining mission performance over the expected lifespan when cluster satellites are launched. Plans for replacements due to random failures should also be established to maintain performance. This study proposed a method for assessing system reliability and availability to maintain mission performance and establish replacement strategies for Earth observation constellation satellites. In this study, a constellation reliability and availability model considering mission performance required for a satellite constellation, situations of satellite backup, and additional ground backups was established. The reliability model was structured based on the concept of a k-out-of-n system and the availability model used a Markov chain model. Based on the proposed reliability model, the minimum number of satellites required to meet mission requirements was defined and satellites needed in orbit during the required mission period to satisfy mission reliability were calculated. This research also analyzed the number of spare satellites in orbit and on the ground required to meet the desired availability during required service period through availability analysis.