• Analytical Science and Technology
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• v.25 no.5
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• pp.292-299
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• 2012

GC/MS has been utilized for many applications due to great resolution and reproducibility, which made it possible to build up the database of mass spectrum, while HS-SPME has the advantage of solventfree extraction of volatile compounds. The combination of these two methods, HS-SPME GC/MS, enabled many scientific applications with various possibilities. In this study, the analysis of trail pheromone excreted from live Camponotus japonicus with the feature of solvent-free extraction was carried out and the optimization for this analysis was performed. The major compounds detected were n-decane, n-undecane, and n-tridecane. Optimization for the best detection of these hydrocarbons was processed in the point of SPME parameter (selection of fiber, extraction temperature, extraction time, etc.). The advantage of the analysis of live sample is to analyze phenomenon right after it is excreted by ants. But the experimental process has restriction of extraction temperature and time because of the analysis of live ants. Establishing the process of HS-SPME GC/MS applied to live samples shown in this study can be a breakthrough for the ecofriendly and ethical research of live things.

• Journal of Korean Home Economics Education Association
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• v.15 no.4
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• pp.37-53
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• 2003

이 연구는 고등학교 $\ulcorner$기술ㆍ가정$\lrcorner$주거 공간 꾸미기 단원의 교수-학습을 위한 WBI 프로그램을 개발하고 평가하는 데 목적이 있다. 이 연구는 WBI 프로그램을 개발하여 주거 공간 꾸미기 단원의 교과 내용을 학습하고 HOME DESIGN 응용 프로그램을 이용하여 실습함으로써 제 7차 교육과정에서 강조하는 웹 기반 수업과 개별학습을 하는 데 활용될 수 있을 것이다. 프로그램은 ADDIE 모형을 중심으로 학습 내용 선정, WBI 프로그램 설계, WBI 프로그램 개발 수업 적용, 평가 과정을 거쳐 개발하였다. 우선 $\ulcorner$기술ㆍ가정$\lrcorner$6개 교과서의 주거 공간 꾸미기 내용을 정리하고 그 내용을 바탕으로 HTML과 PHP, MySQL로 데이터베이스를 구축하여 학습자와 컴퓨터와의 역동적인 상호 작용이 이루어지도록 설계하였다. 또한 온라인의 개별 학습이 가능하도록 주메뉴를 교과서 연구실, 3D 홈 디자인 실습실, 자료 공유실, 종합 평가실의 네 부분으로 구성하여 이론을 약 6시간 동안 학습하고 나서 3시간 동안 실습을 할 수 있도록 하였다. 개발된 프로그램을 수정 보완하고 프로그램의 질을 높이기 위한 목적으로 청주시 C고등학교 1학년 학생 35명과 가정과 교사 3명을 대상으로 시범 적용한 결과를 바탕으로 프로그램의 작동 여부를 화인하고 오류를 고쳐 프로그램의 문제점을 개선하였다. 본 프로그램을 이용한 회원은 4월 20일부터 6월 1일까지 2개 고등학교 학생 70명, 11개 고등학교 교사 11명이었다. 평가 결과 교사들은 본 프로그램에서 가장 유용하게 이용한 부분으로 ‘3D 홈 디자인 실습실(63.6%)’, ‘교과서 연구실(18.2%)’, ‘게시판. 자료실, 묻고 답하기 등(18.2%)’ 순으로 답한 반면 학생들은 ‘3D 홈 디자인 실습실(47.8%)’, ‘교과서 연구실(34.3%)’, ‘게시판, 자료실, 묻고 답하기 등(17.9%)’의 순으로 답하여 유용한 부분에 대한 순서는 일치하나 비율에 차이가 있어 교사들이 ‘3D 홈 디자인 실습실(63.6%)’을 더 유용하게 이용했음을 알 수 있었다. 또한 프로그램을 사용하는 데 있어 교사는 ‘쉬운 편이다’라는 응답이 63.6%로 학생의 24.2% 응답과 차이가 있었으며, 제시된 학습 내용의 양이 ‘적당하다’에 교사가 63.6%, 학생이 48.4%로 답하여 차이가 있었다. 그리고 교사들은 화면 구성이 ‘잘 구성된 편이다(72.7%)’,‘평상시 수업보다 이해에 도움이 되었다(81.2%)’로 답하여 교사들이 학생들보다 본 프로그램에 더 긍정적인 반응을 보였음을 알 수 있었다. 프로그램에 대한 장점과 개선할 점에 대한 개방형 평가는 교사들의 평가와 유사하여 ‘재미있어서 시간이 부족했다’, ‘잘하지는 않았지만, 직접 디자인해서 재미있었다’, ‘어른이 되면 주거 공간 활용을 잘 할 것 같다’, ‘새로운 경험이라 재미있었다’, ‘흥미롭고 재미있었다’, ‘쉽게 되어 있어 좋다’, ‘가구 배치가 잘 되었고. 흠 디자인한 색상이 잘 맞는다’라는 의견이었다. 그러나 주거 공간 꾸미기 WBI 프로그램을 이용한 수업이 컴퓨터에 대한 소양이 부족한 학생과 집중력이 떨어지는 학생에게는 다소 어려움이 있으므로 학생들의 개인차와 학교 실정에 따른 시간 배당 등을 고려하여 학생의 개별학습과 아울러 학교에서 교사의 설명과 함께 수업 시간에 활용할 것을 제안한다.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.2
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• pp.3-8
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• 2011

Recently, the demand for enterprise for service map providing and portal site services of a 3D virtual city model for public users has been expanding. Also, accuracy of the data, transfer rate and the update for the update for the lapse of time emerge are considered as more impertant factors, by providing 3D information with the web or mobile devices. With the latest technology, we have seen various 3D data through the web. With the VRML progressing actively, because it can provide a virtual display of the world and all aspects of interaction with web. It offers installation of simple plug-in without extra cost on the web. LiDAR system can obtain spatial data easily and accurately, as supprted by numerous researches and applications. However, in general, LiDAR data is obtained in the form of an irregular point cloud. So, in case of using data without converting, high processor is needed for presenting 2D forms from point data composed of 3D data and the data increase. This study expresses urban LiDAR data in 3D, 2D raster data that was applied by compressing algorithm that was used for solving the problems of large storage space and processing. For expressing 3D, algorithm that converts compressed LiDAR data into code Suited to VRML was made. Finally, urban area was expressed in 3D with expressing ground and feature separately.

• Analytical Science and Technology
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• v.11 no.6
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• pp.485-494
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• 1998

Ternary and quaternary alloys composed of Mo-Ru-Rh-Pd were prepared and their crystal structure and quantitative chemical compositions were analysed by XRD, WDX, EDX and ICP/AES. The results of X-ray diffraction studies showed that the alloys were crystallized in hexagonal close packing, well known as ${\varepsilon}$-phase with $P6_3/mmc$ of space group. The optimum accelerating voltage for Zr~Cd(40~48) analyzed by EPMA using PET crystal was found to be 15 kV and the linear regression coefficient(R) of atomic number and X-ray intensity was approximately 0.998 without Tc standard specimen. The WDX results of alloys of Mo and Pd by linear regression equations were detected to be 0.1% lower compared to WDX analysis results using standard specimen, while Ru, Rh were detected 3% higher. These alloys were completely dissolved in mixed acid of 12.5 mL HCl and 1 mL $HNO_3$, at $220^{\circ}C$ for 22 hours using autoclave with PTFE vessel. There was no reprecipitating phenomnon when diluted 100 times with 1N-HCl. The results of ICP/AES analysis deviated less than 4% comparing with those of normal WDX analysis.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.741-749
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• 2017

This study aims to provide the technical considerations and implications for the development of soil vulnerability assesment tool based on the review of existing tools and case studies applied both domestically and internationally. For this study, we specifically investigated the basic theories and major features implemented in the screening models abroad. In contrast, one case study of prioritizing the vulnerable districts was presented to identify the research trends in Korea. Our literature review suggested that the characteristic of target areas and contaminants needed to be properly incorporated into soil vulnerability assessment because the current tools in Korea neglected these properties which prevented this tool from being used as a correct measure of soil management and prevention. We also reached the conclusion that in terms of technical aspect, the soil vulnerability assessment tool should be developed based on the physical theory and environmental data that were varied over space and time so that the end-users were able to readily and effectively screen soil vulnerability over large areas. In parallel with technical improvement, great effort needed to be devoted to develop an integrated environmental information system that increased the availability of data and shared various types of environmental data through enhanced multi-agency collaboration.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.274-291
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• 2012

Since the advent of the internet as representative of the development of information communication technology (ICT), information transfer forms have changed rapidly these days. In the new techno-economic paradigms, I would ultimately consider how spatial structures of a knowledge-based service industry have been altered dynamically. To delve into this background, this study conducts an empirical case study of the internet advertising industry, particularly, among the whole advertising industry. Therefore, the primary objective of this study is to identify dynamic characteristics of spatial networks among actors for knowledge creation in Korea's internet advertising industry. In addition, it also is to analyze the formative elements of spatial networks which would have an influence on constructing the space of new economic activities. There are multilateral approaches. This research is classified into types of actors such as inter-firm, intra-firm, and firm-customer, and categorized according to spatial ranges such as local, regional, global levels. In the meanwhile, formative factors of the spatial networks could draw a conclusion from two aspects: inter-firm networks in the process of business in the internet advertising industry, and individual networks in the nonoccupational aspect. Accordingly, the results of this study suggest that actors' networks of two perspectives would make mutually complementary relationships and create new relational spaces in the digital economy.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.59-76
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• 2015

Recent wide spread of embedded devices and technology growth of broadband communication has led to rapid increase in the volume of created and managed data. As a result, data centers have to increase the storage capacity cost-effectively to store the created data. Data deduplication is one way to save the storage space by removing redundant data. This work propose IO extent based deduplication schemes called CORE-Dedup that exploits content-preserving access locality. We acquire IO traces from block device layer in virtual machine host, and compare the deduplication performance of chunking method between the fixed size and IO extent based. At multiple workload of 10 user's compile in virtual machine environment, the result shows that 4 KB fixed size chunking and IO extent based chunking use chunk index 14500 and 1700, respectively. The deduplication rate account for 60.4% and 57.6% on fixed size and IO extent chunking, respectively.

• Informatization Policy
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• v.26 no.4
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• pp.36-61
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• 2019

While smart devices can have a positive impact on work efficiency and productivity by reducing time-space constraints and enabling rapid processing of tasks, side effects can arise from the imbalances between work and personal life. In recent years, as smart devices are increasingly used in work environments, it is more necessary than ever to understand the related phenomenon, find the cause of negative effects, and search for appropriate solutions. This study has developed and verified a theoretical model that shows how the technical characteristics known as the utility of smart devices are converted into negative results such as work-life conflict. As a result of analyzing the collected data from the employees, our study provides significant implications for the researchers, as well as the practitioners and policy makers, regarding various relationships among IT-enabled work flexibility, after-hours work connectivity and work-life conflict, and the new knowledge about the important role of segmentation supplies from the organization.

• Solar Energy
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• v.11 no.2
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• pp.51-62
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• 1991

Heat transfer characteristics for heat retrieving processes in a paraffin-filled horizontal circular cylinder was studied. Theoretical and experimental analyses were carried out. In the theoretical analysis, solid and liquid phases were treated separately. Namely, convection for liquid and conduction for solid phase were investigated respectively. The retrieved heat was calculated from the experimentally determined solidified mass. Furthermore, the effects of initial temperature of the liquid and cooling temperature on the heat discharge rate were also studied. In the heat retrieving process, the governing factor for the solidifying rate is the cooling temperature, because most of the liquid sensible heat is rapidly discharged in the initial stage of solidification. Hence heat transfer mechanism during heat retrieving process can be safely considered as conduction. In the cut of frozen paraffin, there showed an empty space in the upper region. It is caused by the temperature drop in the liquid paraffin. While volume shrinkage caused by phase transition was indiscernible. Irrespective of cooling temperature and initial liquid temperature, solidified mass was well-correlated with the product of Fourier number and Stefan number in the solid phase.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.453-460
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• 2017

In the offshore industry, helicopters are mainly used for transportation of goods or operating personnel between offshore sites and onshore facilities. A helideck is a structure that is required for landing and take-off of helicopters on the offshore structure. There are several shapes of helidecks depending on the type of offshore structures or installation location. Among them, cantilever-type helidecks usually provide more space on the topside of offshore structures and it is safer against potential accidents like fire or explosion. In this paper, the cantilever-type helideck is selected for the research object and topology design optimization is applied for lightweight design of the helideck. A finite element model is then created from the optimal layout of truss structures of the helideck, and structural analysis is performed under various landing conditions and wind loads. Based on the analysis results, the detailed section dimensions of structural members are determined so that the maximum stress at each structure member does not exceed the allowable stress of the structural material. Also, the final optimal design shows significant decrease in the total weight of the helideck.