• Journal of Engineering Education Research
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• v.15 no.4
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• pp.109-117
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• 2012

The purpose of this study is to give the preliminary data and suggestion for introducing and spreading e-learning engineering education through analyzing learning behaviors, learning motivations, and satisfaction of e-learning engineering students. Especially, this comparative study analyzes each research domain according to majors and grades, thereby suggesting more specific and practical results. 2,745 students registered in 38 subjects of e-learning in 2 Universities were analyzed for this study. The study result shows that engineering students are attending around 2 e-learning subjects with a duration of about 30 minutes once a week. The main of learning motivation for e-learning was not easy test level and feasibility of acquiring credit but advantages of e-learning such as freedom of time and space, learning by repetition. The satisfaction scores of e-learning were lower compared to the aspects of system and contents Based on these results, first, an active spread of e-learning to engineering education is necessary because the demand from the engineering students is high enough and they have desirable learning behavior and learning motivation for it. Second, the characteristics of grades need to be taken into consideration on operation of e-learning. Third, a successful e-learning process needs more meticulous and active operation.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.147-167
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• 2012

In this paper, we attempted to theorize the multi-faceted impacts of smart work on economic activities. In this vein, we adopted socio-economic perspective which includes individual, firm, and social support aspects, and explored the variables related to the quality of life among them. First, smart work patterns are categorized as telework, mobile office, teleconferencing, and social collaboration. And relevant variables are extracted with reference to industrial cases and relevant literatures which investigated economic impacts of digital convergence. Next, with the data collected from experts, following delphi method, validation of variables and explorations of significant factors affecting quality of life were conducted by adopting stepwise regression method. The distinguishing traits of this research are two-folds. The one is the investigation of social support and quality of life aspects of smart work, which has been relatively limited in the digital convergence research field. The other is the comparative analysis of smart work advantages by distinguishing individual and firm aspects separately. The result offers useful insights for socio-economic perspective researches on digital convergence application area.

• Journal of the Korean Society of Tobacco Science
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• v.35 no.1
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• pp.20-27
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• 2013

An Electronic Nose(E-Nose) and Gas Chromatography/Mass Spectroscopy (GC/MS) are meanwhile conventional technique to analyze volatile materials in many industries (e.g., food, medicine, environment) and have broad acceptance in the analysis of tobacco products. In this study, an experiment where tin oxide gas sensor array responses and GC/MS profiles are used to characterize the volatile compounds of different cigarettes at the same time is performed and the measurements of two instruments are compared for cigarette samples with a known chemical information. E-Nose and GC/MS were employed to differentiate and match flavored cigarettes with commercial tobacco flavoring agents (lavender, vanilla, peppermint, orange, star anise). For verifying reliability of two systems, the analyses were conducted in terms of amount of flavors in each cigarettes using partial least squares (PLS) and with the principal components analysis (PCA). Various chemical sensors and GC/MS data was reduced into two principal factors (PC1, PC2) for being distinguished with visualized regions. Both systems provided adequate results for odor characteristics of cigarettes in this study with each instrument having its own advantages and disadvantages.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.69-78
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• 2010

Multi-criteria ABC inventory classification is one of the most widely employed techniques for efficient inventory control, and it considers more than one criterion for categorizing inventory items into groups of different importance. Recently, Ramanathan (2006) proposed a weighted linear optimization (WLO) model for the problem of multi-criteria ABC inventory classification. The WLO model generates a set of criteria weights for each item and assigns a normalized score to each item for ABC analysis. Although the WLO model is considered to have many advantages, it has a limitation that many items can share the same optimal efficiency score. This limitation can hinder a precise classification of inventory items. To overcome this deficiency, we propose a context-dependent DEA based method for multi-criteria ABC inventory classification problems. In the proposed model, items are first stratified into several efficiency levels, and then the relative attractiveness of each item is measured with respect to less efficient ones. Based on this attractiveness measure, items can be further discriminated in terms of their importance. By a comparative study between the proposed model and the WLO model, we argue that the proposed model can provide a more reasonable and accurate classification of inventory items.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1729_1730
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• 2009

This paper presents comparative experimental results of PI sliding mode control and PI control for a heavy duty robot which can handle an object of 600kg, The gains of the PI control was determined by TAE(Trial and Error) method. This paper presents a novel approach for the decoupling of the states cross-coupling using sliding mode control. The sliding mode control methode is based on the error between reference speeds and the actual speed. The proposed method has the advantages of PI control performance and the sliding mode control robustness. Its first step is to design PI controller, then the sliding mode control input term is added to it. This makes actual implementation of the controller easier. The robot and motion controllers were designed and made by author. The good control performance of the heavy duty robot was obtained by using simple algorithm. This means that the robot was designed very well in control respect.

• Environmental Engineering Research
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• v.22 no.4
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• pp.363-368
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• 2017

The external diseconomy is hampering sustainable development of the city logistics sector. Burdens on urban environment imposed by the city logistics industry have been put in the spotlight. Based on the principle of Life Cycle Analysis, the comprehensive environment impact for city logistics systems is measured. Firstly, with the city logistics service chain as a whole, its business processes and their interactions with environment are analyzed. In total four types of major environment impact categories are determined. Secondly, case study is made on three city logistics operators located in Jing-Jin-Ji region of China with different business modes, respectively self-operation mode, joint distribution mode and the $3^{rd}$ Party Logistics or 3PL mode. Through analysis of energy consumption and emissions for various business processes, their comprehensive environmental impact values are finally obtained. Thirdly, horizontally comparative analysis is carried out to these three modes of the urban logistics distribution systems. Results show the advantages of the 3PL and the joint distribution modes in developing greener urban logistics distribution. Future research avenues and policy suggestions are proposed finally.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.4
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• pp.99-109
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• 1996

This study, a preliminary one to construction of standardized rural resources evaluation system, aimed at catching the valuing structure of rural and urban residents cn rural resources through interview. The questionnaire employed in our surveys was focussed on; opinion about the advantages and disadvantages of living in rural areas, usual impression on rural life style, viewpoint on preservation of cultural heritages and conservation of natural environments, priority item listing for improvement/development of rural village. Generally, regardless of interviewee's personal characteristics, the peaceful and comfortable life in the lovely/clean environment was indicated as a representative advantage of rural life. However, in minor aspects, there were recognizable differences by their living and thinking patterns, so, a deep and systematic study should be progressed to harmonize or integrate the pluralistic valuing trends on rural affairs in future. The valuing structure on rural resources from this study showed much more varieties according to age-and occupation-groups, while young generation strongly hold self-orii-ented and ambiguous thinking. Because this trend will grow more deeply and widely in future, the resoruces evaluation system for rural purposes should be established as a rational base for decision-making on rural development strategies.

• Journal of Korea Multimedia Society
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• v.18 no.6
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• pp.742-752
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• 2015

The communications through the power lines are called as the PLC and this is a common name for the communication modes for the information delivery. This technology transmits the data through the power lines on which the information is stored with the form of high frequency signal. The characteristic of the frequency signal is that the signal can be separated from the power line through exclusive power line modem and transmitted to the terminal devices. In this paper, 'In-home Headcount' checking algorithm using Wi-Fi and taking above mentioned advantages is proposed, and the basic Technology for such Solitary Senior Citizen's Lonely Death monitoring system has been designed and implemented. The comparative analysis has been conducted in this paper with the test-operated and test bed-completed 'Hyosimi 119 Safety-Welfare System' which is still being tested since 2008. With the 'In-home Headcount Checking Algorithm', Wi-Fi connection/disconnection status and SSIDs of relevant Wi-Fis will be checked. We expect that our proposed method will become as the basic Technology which can prevent lonely deaths of elderly people living alone. Since the PLC technology can be normally implement all the functions used on internet anticipate that the technology could be applied to many areas to construct a new form of communication network.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.8-22
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• 1999

This study was performed to comparatively evaluate selected Human Reliability Analysis (HRA) methods which mainly focus on cognitive error analysis, and to derive the requirement of a new human error analysis (HEA) framework for Accident Management (AM) in Nuclear Power Plants (NPPs). In order to achieve this goal, we carried out a case study of human error analysis on an AM task in NPPs. In the study we evaluated three cognitive HEA methods, HRMS, CREAM and PHECA, which were selected through the review of the currently available seven cognitive HEA methods. The task of reactor cavity flooding was chosen for the application study as one of typical tasks of AM in NPPs. From the study, we derived seven requirement items for a new HEA method of AM in NPPs. We could also evaluate the applicability of three cognitive HEA methods to AM tasks. CREAM is considered to be more appropriate than others for the analysis of AM tasks, HRMS is also applicable to the error analysis of AM tasks. But, PHECA is regarded less appropriate for the predictive HEA technique as well as for the analysis of AM tasks. In addition to these, the advantages and disadvantagesofeachmethodaredescribed.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.181-195
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• 2005

This study is to provide a comprehensive overview of the changing vegetable sector of Chinese agriculture and to analyse the competitiveness of Chinese vegetable production. China now produces more than 60% of the world's vegetable supply and that 150 million people are engaged in vegetable production, processing and marketing since the reform of vegetable industry structure started in the late 1980s. As a labour abundant industry, China also features more comparative advantages in the vegetable trade. Although China's vegetable exports still accounts for only 1% of total production, the 5 million tons of export in 2003 makes China one of the largest vegetable players in the international markets. When estimating competitiveness of China's vegetable industry, China's producers' prices for vegetables are founded to be only from 10%~40% of what they are in Korea, while most of China's vegetables have also strong competitiveness in quality. As China joined the WTO in 2001 and expects to increase market share in vegetable trade, the development strategy for Korea's vegetable industry are suggested as follows; 1) focusing on the technology for the growth of vegetable productivity, 2) developing the higher value added vegetable industry through processing, 3) expanding the exported area and leading vegetable varieties.