• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
• /
• pp.159-163
• /
• 2003

In this study, the DC dielectric breakdown of epoxy composites used for PCB material was experimented and then its data were simulated by Weibull distribution equation. The more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical, and the breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised, the electric field is concentrated, and the acceleration of electron and the growth of electron avalanche are early accomplished. From the analysis of Weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5[kV/mm].

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2003년도 학술대회논문집
• /
• pp.111-116
• /
• 2003

Recently, power-electronics equipments or machine that microprocessor is included and computers have been installed continuously in industrial process or region of electronics customer. So concern for power quality, especially sags has been increased. Because those equipments are very sensitive to sags. The sag is phenomenon that magnitude of load voltage temporarily decreases because of power system fault. If a certain equipment in industrial process have any trouble result from sag, it can cause utility to be charged for enormous economics loss. Therefore it need to analyze the characteristic of sag and then mitigation method for sags in distribution system in oder to increase reliability. This paper gives an overview of sags characteristic due to short circuit fault in distribution system and after a general discussion of the various forms mitigation, gives a sags mitigation method with concentrating on mitigation-device interface method, especially FCL that is Fault Current Limiter.

• Structural Engineering and Mechanics
• /
• 제87권1호
• /
• pp.85-94
• /
• 2023

In the present work, thermal buckling and post-buckling behaviors of imperfect graphene platelet reinforced metal foams (GPRMFs) doubly curved shells are examined. Material properties of GPRMFs doubly curved shells are presumed to be the function of the thickness. Reddy' shell theory incorporating geometric nonlinearity is utilized to derive the governing equations. Various types of the graphene platelets (GPLs) distribution patterns and doubly curved shell types are taken into account. The nonlinear equations are discretized for the case of simply supported boundary conditions. The thermal post-buckling response are presented to analyze the effects of GPLs distribution patterns, initial geometric imperfection, GPLs weight fraction, porosity coefficient, porosity distribution forms, doubly curved shell types. The results show that these factors have significant effects on the thermal post-buckling problems.

• 한국지반환경공학회 논문집
• /
• 제15권1호
• /
• pp.25-34
• /
• 2014

본 연구의 목적은 개량체 구조형상변화에 따른 복합지반에서의 역학 및 침하특성을 분석하는 것에 있다. 본 연구의 실험은 원형토조에 강도 및 치환율별로 격자형 개량체를 만들어 복합지반을 조성한 후 응력을 재하하는 방식으로 총 9 케이스를 수행하였다. 또한 심도별 응력분포 및 응력분담비 등을 분석하기 위해 유한요소해석을 실내 모형실험과 동일조건으로 모델링하여 해석하였다. 연구결과, 격자형 개량체로 구성된 복합지반은 원형 개량체에 비해 저치환율을 제외한 중간 및 고치환율에서 응력분담비가 증가하며 그 결과, 침하량은 감소하는 경향을 보였다. 본 연구는 구조형상 변화에 따른 형상효과비 및 침하저감계수 제시를 통해 부족한 복합지반의 개량체 구조형상에 대한 연구 참고자료 및 향후 추가 연구에 도움이 될 것으로 판단된다.

• Animal Systematics, Evolution and Diversity
• /
• 제7권1호
• /
• pp.127-150
• /
• 1991

한국산 산호충류 중 돌산호류의 계통분류학적 연구를 하기 위하여 1969년부터 1986년까지 우리나라의 삼면연안과 도시지방(35개지역)으로부터 채집된 표본들을 동정 분류하고 지리적 분포도 고찰하였다. 그 결과 5아목 7과 15속 24종이 밝혀졌으며 이 중에서 7종은 한국 미기록종이었다. 한국산 돌산호류를 분포형으로 보면 열대형(16종, 66.7%)과 온대형(8종, 33.3%)으로만 되어있고, 해역별로 보면 제주도 해역에 16종(4온대종,12열대종)으로 가장 많은 종이 분포하였으며 황해에 3종 (2온대종, 1열대종)으로 가장 적은 종이 분포하였다. 해역간 유사계수를 근거로 보면 대한해협과 동해 사이의 유사성(0.596)이 가장 크고, 황해와 제주도해역 사이의 유사성(0)은 전혀없었다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제14권2호
• /
• pp.211-215
• /
• 2008

통신 미들웨어는 응용프로그램에서 담당하던 데이타 교환을 대행한다. 여러 가지 통신 미들웨어 기술이 있지만, 다양한 디바이스들이 동적으로 네트워크 도메인을 형성하고 동일한 타입의 데이타를 빈번히 주고받는 통신환경에서는 데이타 중심 발간/구독 방식의 데이타 교환이 적합하며 OMG의 DDS(Data Distribution Service)에서 이러한 방식을 표준으로 채택하였다. 본 연구에서는 OMG의 DDS 표준 규격을 준수하고 시스템 관리 자동화가 가능한 데이타 분배 서비스 시스템인 ReTiCoM을 설계하고, 그 성능을 유사한 미들웨어인 JMS와 비교 분석하였다.

• 유통과학연구
• /
• 제8권4호
• /
• pp.25-34
• /
• 2010

While jujubes are mainly sold in dried forms as wholesome foods, sacrificial food and so on, processed foods from jujube are neither highly recognized nor in high demand. Hence, this study has proposed ways to enhance the demand for jujube processed foods and will help prepare the ground for efficient marketing strategies, based on the survey result on the pattern in which customers in Korea purchase jujube-processed foods. The conclusion for this study has been derived by researching the relevant literature and analyzing the relevant company data and customer survey results. The study implies the following points regarding enhancing the demand for jujube-processed foods. First, long-term solutions are necessary. These may include establishing a technological system that can produce various foods processed from jujubes, and improving the customer accessibility in accordance with the changes in the retail environment. To implement these solutions, it is necessary to familiarize the customers with jujube-processed foods by securing a good sales network and through active promotion and advertising. Second, systematic marketing strategies are needed, which may be applied in developing the products as well as distribution and promotion methods and prices that correspond with the changes in the customer environment and the different tastes for various age, gender and residential area groups.

• 유통과학연구
• /
• 제21권2호
• /
• pp.77-89
• /
• 2023

Purpose: At the end of the pandemic, many digital startups had negative performances. For that, this study aims to analyze the mediating role of entrepreneurial competence and digital entrepreneur career maturity. Seven hypotheses were proposed, namely the effect of entrepreneurship orientation, digital entrepreneurship experience, and digital entrepreneur career maturity on digital entrepreneurial competence, the effect of digital entrepreneurial experience on digital entrepreneurial career maturity, the influence of entrepreneurial orientation, entrepreneurial competence, and digital entrepreneur career maturity on business performance. Research design, data and methodology: The population is digital entrepreneurs in Central Java, Indonesia with a business duration of more than 4 years. The number of samples as many as 184 people were carried out by questionnaire distribution through face-to-face, email, and Google forms. Partial Least Square Structural Equation Modeling was used to test the path coefficient statistics. Results: The results showed that all the hypotheses proposed were accepted. Digital entrepreneurial competencies and digital entrepreneurial career maturity are also proven to have a mediating role. Conclusions: The findings of this study can contribute to the development of digital entrepreneurship research. Practically, the government's role is needed to facilitate the three main elements of digital business: e-commerce, payment methods, and distribution channels.

• 유통과학연구
• /
• 제20권10호
• /
• pp.67-77
• /
• 2022

Purpose: This study aims to determine the online shop service performance of fresh food products distribution, consumer motivation, and their relationship during the COVID-19 pandemic. Research design, data, and methodology: A survey was conducted online using Google Forms on 100 consumers of TaniHub application users. Data in the form of scale were analyzed descriptively to explain the service performance and consumer motivation. The service performance consists of technical services and marketing services. Technical service indicators consist of payment, delivery, and products. Meanwhile, the marketing service indicator consists of promotions and prices. The consumer motivation is characterized by reference, actualization, and lifestyle. The relationship between the two was analyzed using Spearman's rank correlation. Results: The most consumers are millennial generation who were active in social media. They are employees with Bachelor's and Master's qualifications and included in the middle economic groups. TaniHub online shop had good technical and fair marketing performance. The motivation of online shop consumers of fresh food products through the TaniHub application was high. Conclusions: The findings discovered a significant relationship between online shop service performance and consumer motivation. It indicates the need for improvement in marketing services, especially promotions, to improve the performance of this e-agribusiness company.

• 유통과학연구
• /
• 제22권2호
• /
• pp.31-40
• /
• 2024

Purpose: This study aimsto assert trust as an important mediator in the service business. The research topic relatesto service businesses that have low exposure to comparative information and weak consumer positions in terms of law, such as the beauty clinic businesses in Indonesia. Research design, data, and methodology: This study uses explanatory and purposive sampling. A survey was conducted among 268 Indonesians, collected by distribution via Google Forms. The hypotheses were tested using AMOS software. Results: The results indicate that trust did not have a significant role in mediating brand awareness, service quality, and price perception on revisit intention, but only mediated satisfaction. Furthermore, this study discloses the neutralization attitude and dissonance behavior represented by trust mediation. Conclusions: These findings attempt to expand the literature on the role of trust in the service business. However, the beauty clinic businessin Indonesia infers misbehavior. Misbehavior is caused by vulnerable conditionsin which consumers are unable to share their experiences with other consumers. The reason is that the defamation law in Indonesia is often implemented in the wrong direction. This must be corrected so that consumers obtain their rights and create a mutually beneficial relationship between beauty businesses and consumers.