• Korean Journal of Materials Research
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• v.24 no.6
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• pp.326-337
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• 2014

The use of solar energy generation is steadily increasing, and photovoltaic modules are connected in series to generate higher voltage and power. However, solar panels are exposed to high-voltage stress (up to several hundreds of volts) between grounded module frames and the solar cells. Frequent high-voltage stress causes a power-drop in the modules, and this kind of degradation is called potential induced degradation (PID). Due to PID, a significant loss of power and performance has been reported in recent years. Many groups have suggested how to prevent or reduce PID, and have tried to determine the origin and mechanism of PID. Even so, the mechanism of PID is still unclear. This paper is focused on understanding the PID of crystalline-silicon solar cells and modules. A background for PID, as well as overviews of research on factors accelerating PID, mechanisms involving sodium ions, PID test methods, and possible solutions to the problem of PID, are covered in this paper.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.12-19
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• 2004

A Molded Case Circuit Breaker (MCCB) is an electric control device to interrupt the abnormal currents which result from the over-loads or short-circuits. Its malfunction will result in severe accidents. In the development of the MCCB, higher current-rating and improved thermal performance become more and more important in providing the safe function and reliability for the modern devices requiring small scale and high performance. It is also very important to consider the factors of temperature rise in the design of MCCB. The major reasons of temperature rise in the MCCB result from the resistances, which are come from the connection and contact surfaces. These resistances are influenced by current, time, configuration of contact surfaces and applied voltage. In order to predict the temperature distribution inside MCCB, we have simulated the model with some assumptions and simplifications, using commercial code ICEPAK. To verify the results of temperature field analysis, the numerical results are compared with experimental ones for the same model. The results show a good agreement with actual temperature rise obtained by experiments.

• Culinary science and hospitality research
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• v.17 no.3
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• pp.33-46
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• 2011

This study is concerned with the effect of a brand symbol of a family restaurant on brand image, preference, and purchasing intention. With regard to analysis methods, the study carried out a reliability test and a validity test concerning a precedent research concept, ahead of verifying the hypothesis by using the SPSS Ver. 16.0. Also, the study conducted a frequency analysis, technical analysis, exploratory factor analysis, and regression analysis for verifying the hypothesis. As a result of the research, regarding a brand symbol as a visual symbol, three factors including a functional factor, a value factor, and an aesthetic factor were extracted, and of them, the functional factor and an aesthetic factor were discovered to influence of the brand image and preference which affected purchasing intention. In addition, consumers preferred a logo type that includes a company name or a brand name rather than a picture or a mark type of a symbol regarding a brand symbol, and they answered that outdoor advertising would raise awareness more than TV advertising. Based on these results, using a logo type symbol and the mix of outdoor advertising and TV advertising should be considered for brand launch.

• Survey Research
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• v.10 no.2
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• pp.115-136
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• 2009

This paper examines the past tendencies of survey study on military organizations and explores the directions and alternatives of research study based on one of the main military characteristics of rank structure. Military survey study has limitations in confirming the credibility of the research results and in supporting implications on the diverse subjects due to the constraining research environment in the military. This study deduced survey designs and analytic methods fit for the research objective upon multidimensionally grasping the characteristics of the hierarchical rank structure which influences the survey process aid its result crucially. It proposes that the future direction of military survey study is to elaborate research method and multidimensionalize analytic methodology. More specifically. this paper insists that it is necessary to design method and process of the survey delicately and to develop analytic methodology which can analyze diverse factors.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1285-1295
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• 2011

In this study, occurrence status of nonpoint pollutants and characteristics of discharge by each nonpoint pollutants were examined through monitoring on nonpoint pollutants caused when raining in vineyard belonging to the agricultural area of various land use patterns. Also, the first flush analysis limited to studies on the existing non-percolation area was applied to percolation area to ascertain availability and criteria of study. Various water quality and sluice of nonpoint pollutants were analyzed, based on which discharge of nonpoint pollutants in agricultural area was ascertained to be influenced greatly by artificial factors such as period, cultivation, management, etc. Meanwhile, the first flush phenomenon at agricultural area was ascertained to occur, and the first flush was quantified through calculation of the first flush ratio. If MFF30 is based, discharge load by each nonpoint pollutants caused when raining was investigated to include 40.8% on the basis of total discharge. In case of SS in pollutants showed the highest first flush phenomenon of 64.8%. Through such a result, calculation possibility of the initial rain criteria was ascertained, and it was determined that reliability-assured criteria were calculated through further monitoring.

• Korean Institute of Interior Design Journal
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• v.16 no.1 s.60
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• pp.126-134
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• 2007

This study researches the effectiveness of virtual experiences as an evaluation method in design. For the study, I researched the result on the spatial recognition before, abstracted visual objects and factors in recognition process and made up 43 inquiries for the evaluation through the experts group. Besides, set the analytical code between recognition factor and spatial constituents, made analysis the result from it. From April 1st to June 30th in 2004, the virtual model of educational place, college main building and city library was established as a subject of the research and studied the result. The methods that are used for the study are frequent analysis, T-test, reliability analysis, factor analysis etc. and SPSSWIN Package is used for the statistic analysis. There were two times of analysis on the evaluation to analyze the effect of virtual models on the web basis, one group evaluated the virtual building same as real and the other group evaluated the building site. Then analyzed the differences and correlation between the two. In result, college building, the first subject of study, and the second city library shows that made little differences between on the spot evaluation and virtual evaluation. Therefore, it is considered that the design evaluation with virtual model on the web basis has a vantage. But some problems founded that solved between preceding and present research through the feedback. It is as follows, 1. detection of problems that insufficience validity in the first survey. 2. found some not-validity inquiries. 3. detection of necessities that qualitative improvement and technical repletion in virtual environment.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.63-69
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• 2018

This research analyzed the effects of IT entrepreneurship education on the will to start a new business by reemployment trainees. A survey was carried out on 187 reemployment trainees from May 15, 2017 until July 15, 2017. The SPSS 22.0 Program was utilized as the analysis method, and a reliability analysis, frequency analysis, multiple regression analysis, and correlation analysis was carried out. Research showed that statistics for IT entrepreneurship education on the will to start a new business by reemployment trainees was higher than the overall average, and there was a positive correlation between IT entrepreneurship education and Willingness. Reemployment trainees' IT entrepreneurship education had a significant effect on the sub factor Entrepreneurship Willingness, but did not have a significant effect on sub factors such as education content, lecturer, and education facilities. This research is considered to be essential baseline data for managing entrepreneurship education programs that increases reemployment trainees' Entrepreneurship Willingness through IT entrepreneurship education.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.2
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• pp.223-230
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• 2013

Recently, a large number of corporations are adopting cloud solution in order to reduce IT-related costs. By the way, Digital Trace should have admissibility to be accepted as digital evidence in court, and integrity is one of the factors for admissibility. In this context, this research implemented integrity verification test to VM Data which was collected by well-known private cloud solutions such as Citrix, VMware, and MS Hyper-V. This paper suggests the effective way to verify integrity of VM data collected in private cloud computing environment based on the experiment and introduces the error that EnCase fails to mount VHD (Virtual Hard Disk) files properly.

• The KIPS Transactions:PartD
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• v.13D no.1 s.104
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• pp.133-138
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• 2006

Electric commerce of surpassing the traditional one appeared before the public and has currently led the change in the management of enterprises. To establish and maintain good relations with customers, electric commerce has various channels for customers that understand what they want to and suggest it to them. The bulletin board and e-mail among em are inbound information that enterprises can directly listen to customers' opinions and are different from other channels in characters. Enterprises can effectively manage the bulletin board and e-mail by understanding customers' ideas as many as possible and provide them with optimum answers. It is one of the important factors to improve the reliability of the notice board and e-mail as well as the whole electric commerce. Therefore this thesis researches into methods to classify various kinds of documents automatically in electric commerce; they are possible to solve existing problems of the bulletin board and e-mail, to operate effectively and to manage systematically. Moreover, it researches what the most suitable algorithm is in the automatic classification of Q&A documents by experiment the classifying performance of Naive Bayesian, TFIDF, Neural Network, k-NN

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4186-4192
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• 2012

Because wind turbines are larger and more off-shore construction due to economic and environmental factors, it is more difficult to access the wind turbine as well as the necessary parts and the maintenance costs are increasing. So, we need to minimize fault elements and to prevent a secondary accident at failure through monitoring to reduce maintenance costs and to increase reliability of operation. In this paper we have implemented ZigBee based wireless sensor nodes and network for wind turbine condition monitoring using temperature, humidity, voltage, current, wind direction, and wind speed sensors. ZigBee wireless sensor nodes signals are transmitted to a central monitoring system via routers. Also, the sensor signals are collected and processed using LabVIEW program to monitor the wind turbine conveniently. The administrators and users can monitor the condition of wind turbine at remote site in real time over TCP/IP.