• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.231-234
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• 2009

IEC 61850 based substation automation system is operating under digital network with a number of IEDs and a HMI as relation of server and client. In case of IEDs, before implementing the system, all of the system integrators require IEC 61850 certificate from individual IED manufacture. Otherwise, there is nothing to verify IED for constructing substation automation system at the real substation. This paper shows verification strategy of IEC 61850 communication reliability such as association /release, report, dataset and four type control function.

• Current Photovoltaic Research
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• 제6권3호
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• pp.69-73
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• 2018

PV system is consisted with PV module, inverter and BOS(balance of system). To have robustic operation more than 20 years, the expected and guaranteed durability and reliability of products should be met. Almost components of PV system are qualified through IEC standards at test laboratory. But the qualification certificate of product does not ensure long-term nondefective operation. PV module's expected life time is nowadays more than 20 years and annual maximum power degradation ratio would be less than -1%. But the power degradation ratio is basically based on real data more than several years' record. Developing test method for ensuring annual maximum power degradation ratio is very need because there are many new products every month with new materials. In this paper, we have suggested new test method under continuous artificial light irradiation test condition for analyze expected maximum power drop ratio.

• 한국통신학회논문지
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• 제28권9C호
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• pp.908-922
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• 2003

최근에 PKI(Public Key Infrastructure)는 인증 경로 고리 작업을 사용자로부터 Delegated Path Discovery (DPD)와 Delegated Path Validation (DPV) 서버에게로 위임하는 추세이다. DPD/DPV 서버 구현의 최적의 조건은 높은 신뢰성을 제공하면서 저렴한 비용과 단순한 구현을 통해 구축하는 것이다. 본 논문에서는 사용자들이 가장 신뢰하는 신뢰 CA(Trusted CA)에 VA(Validation Authority)기능을 추가하여, 이를 DPD/DPV 서버로 사용하는 새로운 인증 경로 처리 기법을 제안하였다. 제안한 기법은 기존의 신뢰 CA를 위임 서버로 사용하기 때문에 단순한 구현을 통해 높은 신뢰성을 획득할 수 있다. 더불어, 경로 처리 작업으로 인한 신뢰 CA의 부담을 감소하기 위해서, 서명 검증 작업을 경로 상의 다른 CA들에게 위임하고, 반복되는 경로에 대한 처리 작업을 생략하도록 함으로서, 신뢰 CA를 이용한 검증 작업이 보다 효율적이고 빠르게 수행될 수 있도록 하였다.

• 복식문화연구
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• 제20권2호
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• pp.169-183
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• 2012

This study was aimed at finding out the preferences and satisfaction levels regarding the type of fashion retailer's sales promotion based on consumers' empirical characteristics. A total of 223 questionnaires were used for the survey of this study. The methods of this study were descriptive analysis, factor analysis, reliability tests, one-way ANOVA, $t$-tests and ${\chi}^2$-test. The consumer groups were divided by habitual experience and self-evaluated knowledge relate to apparel product. The results of this study showed that consumers have different preferences and post-utilization satisfaction regarding the type of sales promotion offered by fashion retailers. Consumers with more experiences in apparel product and with higher self-evaluated knowledge were more active in utilizing the benefits offered through the value-added type of sales promotions, such as the gift certificate or coupon. Consumers with more experience in apparel product also showed higher satisfaction with both the utilitarian and hedonic types of sales promotions, such as gift certificate offer, special price, price discount event, and coupon or courtesy card offer. Furthermore, consumers with higher self-evaluated knowledge showed higher satisfaction with the utilitarian types of sales promotion, such as gift certificate offer and regular sale. Therefore, by identifying the accurate understanding of consumers'empirical characteristics, an enterprise might be able to satisfy consumer by offering more appropriate and subdivided types of sales promotion.

• 한국조리학회지
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• 제20권5호
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• pp.76-83
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• 2014

This article examines the effects of education service quality of culinary education facility on the learning outcome. For this, items for figuring out the relation between education service quality and the learning outcomes has been deducted through IPA regarding education service quality. Further, the factors of education service, which is for verifying the effects of relevant experiences (culinary certificate) have been examined according to advanced studies. Self administered questionnaires have been prepared by 231 samples in total and the collected data have been analyzed through frequency, factor, reliability and regression analyzing methods by using SPSS 18.0. The results from paired t-test performed on the importance and performance of culinary education service quality indicate that expertise, level of knowledge, education method of instructor and additional convenience facilities (locker and lounge etc) are the most important factors respectively. The results from IPA analysis show that the quadrant 1 includes knowledge level, education method, kindness of instructor. The quadrant 2 contains awareness of instructor while the third one includes culinary facility, tool structure and convenience facility. In addition the quadrant 4 includes hygiene of learning place. According to the results from hypothesis test, education service quality affects learning outcome and the experience (certificate) of learner from culinary education facility results in difference in education service quality and awareness of learning outcome therefore the hypothesis is partially verified.

• 한국IT서비스학회지
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• 제17권1호
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• pp.59-77
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• 2018

Software process (SP) authentication is a certification system designed in order to improve software process and ensure software reliability of the Korean small and medium enterprises (SMEs). It is composed of 3 grades, 17 evaluation items and 70 detailed evaluation items (software process). In order to certificate grade 2, 42 detailed evaluation items must be satisfied. In order to certificate grade 3, all 70 detailed evaluation items must be satisfied. SMEs are more vulnerable to manpower and material resources than the major company. Therefore, it is difficult for SMEs to invest in the long term to improve the software process. If we can provide the core evaluation items to SMEs, SMEs will be able to improve software quality more efficiently and effectively. It can be used as a short way to acquire SP authentication. The evaluation items of SP are defined as influencing each other. Therefore, the core evaluation items might be established using related techniques. Although we searched for previous researches and related informations, the associated study was insufficient. In this study, ANP (Analytic Network Process) technique was applied, and the core evaluation items of SP authentication were established. SMEs will be able to acquire SP authentication more easily using the core evaluation items. Finally, we expect that this study will be used as a basis material for creating the SP 2.0 version.

• 한국태양에너지학회 논문집
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• 제32권5호
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• pp.108-117
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• 2012

The purpose of Green Building Certification System is to promote the environment-friendly building construction as the life-cycle environmental performance of a certain building is assessed and certified nationally(domestically). By the way, a building can get the green building certificate just with the minimum standard in prerequisite assessment criteria and with the designated scores in totals. GBCS consists of 9 assessment issues and it has 4 grades. Nevertheless the 1st. grade green building has uneven scores in each issue. In other words, it has even 0 point in a special issue. Due to the above problem, the discrimination and reliability in the GBCS grading and scoring has to be secured. This study aims at a new grading and scoring system equipped with the discrimination and reliability through analysing the scores of prerequisite assessment criteria and the scores by issues in the actually certified green office buildings.

• 디지털산업정보학회논문지
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• 제12권1호
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• pp.71-79
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• 2016

The main security threats in MANET are integrity and non-repudiation. In the meantime, a lot of secure routing protocols have been designed in order to block these security threats. In this paper, partnership-based authentication technique is proposed in order to provide participation exclusion of network and non-repudiation for the nodes. The proposed technique is a technique that participates in data communication for only the nodes receiving the authentication through the authentication process for the nodes. For this, the proposed technique is largely consists of two steps. The first step is the process that issued the certificate after the reliability for the nodes participating in the network is evaluated. And in the second step, the key exchange agreement with the neighbor nodes is performed and data communication is made after setting security path with responding nodes. The level of security in data transmission is improved because the process of path setting is performed through cooperation with a neighboring nodes having high reliability during the course of these two steps. The superiority of proposed technique in this paper was confirmed through the comparative experiment.

• KEPCO Journal on Electric Power and Energy
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• 제4권1호
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• pp.19-24
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• 2018

가스터빈 동익에 대한 지속적인 국산화 개발이 추진되어, 국내 정밀 주조 기술을 향상시키고, 동익의 유지 보수 비용을 낮추는 등의 직간접적인 긍정적 효과를 가져왔지만, 여전히 국산화 개발품이 발전소에서 안정적인 실사용이 가능한지에 대한 우려가 존재한다. 향상된 소재와 주조기술을 바탕으로 조직학적, 기계적 성질에서 충분한 품질을 확보하였더라도, 개발품을 대상으로 다양한 신뢰성 검증이 요구되는 이유이다. 고속회전시험기는 로터, 디스크 등의 회전체에 원심력을 가하여, 이에 따른 제품의 특성을 분석하기 위한 시험장비로 일반적으로 과속도시험을 통한 최종적인 품질검사에 주로 사용된다. 본 논문에서는 전력연구원에 구축된 고속회전시험기를 활용한 가스터빈 동익에 대한 과속도시험을 포함한 저주기피로시험 사례를 중심으로 신뢰성 시험 및 평가 결과를 기술하였다.

• 한국기계가공학회지
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• 제13권1호
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• pp.16-22
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• 2014

Resonance refers to the magnification of a structural response which occurs when a linear lightly damped system is driven with a sinusoidal input at its natural frequency. An exploratory vibration test (a natural frequency measurement test) is very important for the vibration testing of machine parts, as the value measured in an actual laboratory affects test results. For this reason, it is necessary to estimate the measurement uncertainty to verify the reliability of this type of test. In this study, measurement uncertainty is estimated based on three uncertainty factors. The uncertain factors are the measured points in the machine parts, the resolution of the vibration equipment, and uncertainty of the calibration certificate.