• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.8
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• pp.692-700
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• 2014

In this work, satellite FE (finite element) model updating for the prediction of the effect of micro-vibration is described. In the case of satellites launched in low earth orbit, high agility and more mission accomplishments are required by the customer in order to procure many images from satellites. To achieve the goal, many mechanisms, including high capacity wheels and antennas with multi-axis gimbals have been widely adopted, but they become a source of micro-vibration which could significantly deteriorate the quality of images. To investigate the effect due to the micro-vibration in orbit on the ground, a prediction is conducted through an integrated model coupling the measured jitter sources with FE (finite element) model. Before prediction, the FE model is updated to match simulation results with the modal survey test. Subsequently, the quality of FE model is evaluated in terms of frequency deviation error, the resemblance of mode shapes and FRFs (frequency response functions) between test and analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.3
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• pp.321-330
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• 2020

The purpose of this study is to present the appropriate standby space for the mechanical parking lot considered parking queue. This analysis is based on the field-study by results of the influential factors on the parking queue of mechanical parking lots in the commercial area of Gwang-ju metropolitan city. In this study, the parking queue was analized through the simple modeling using Vissim based on average service rate and average arrival rate from the result of field-study. As a result of applying the field survey products to the theoretical queue model, no significant result was obtained when the traffic intensity exceeded 1. Therefore, parking queue was analyzed through simple modeling using Vissim, and the model for calculating the proper parking queue size of the mechanical parking lot by size was derived. The model for estimating of an appropriate mechanical parking standby space considering parking queue presented in this study is expected to be a criterion for considering the appropriate parking space of a new building, and also it can be used to minimized the traffic impact due to the parking queue by the lack of standby space.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.101-105
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• 2007

The people who lived in Fujian district along the south-eastern coast of China long ago began to construct ships and go fishing. For this reason, they grasped sound navigation skills and gained rich navigation experience. These skills and experience laid basis for the following large-scale overseas trade. In the Tang dynasty, with the development of economy, the people who lived in Fujian district started to leave home town and engage in overseas trade. In the Song dynasty and the Yuan dynasty, with the fast development of overseas communication, more and more Fujian maritime merchants, navigating the Fujian ships which were safe, fast and could arrive at destination on time, engaged in overseas trade. The Fujian ships made it possible for the Fujian maritime merchants to shorten trade time, catch business opportunity, level up the chance of success in trade and make full use of capital. As a result of this, Fujian maritime merchants gained fast development and they reached far areas such as eastern Asia, south-eastern Asia, southern Asia, and eastern Africa. This study deals with the issues such as the reasons for the development of Fujian maritime merchants, the trade engaged in by Fujian maritime merchants, the Fujian ships which played a decisive role in the overseas trade of Fujian maritime merchants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.297-307
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• 2017

There are many underground spaces available in an urban environment and they represent an important factor for efficient land use. Especially, underground shopping centers perform both physical and commercial functions at the same time and are frequently used as a means of achieving the revitalization of the city center. However, the underground shopping centers that were developed in the past sometimes led to recession due to their deterioration. This study was carried out for the purpose of proposing alternative methods for the (revitalization) of underground shopping centers. A survey was conducted on seven underground shopping centers in the Busan metropolitan area to understand the factors that determine their user satisfaction and future improvement. The survey data was analyzed using an ordered logit model. As a result of the analysis, service satisfaction, underground environment satisfaction and public facility satisfaction were selected as significant variables. It was concluded that it is necessary to take these factors into consideration, appropriately, when developing a new or renewing an existing underground shopping mall.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.900-906
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• 2011

To investigate concentration and sources of PCDD/Fs and Co-PCBs in sediments, total 52 sediment samples were measured at 17 sites in Geum River. As a result of analysis, total concentrations of PCDD/Fs and Co-PCBs were ranged from not detected (N.D.)~193.47 pg/g-d.w. (mean value: 84.52 pg/g-d.w) and 0.34~359.19 pg/g-d.w (mean value: 114.65 pg/g-d.w.) respectively. Also, toxic equivalent (TEQ) concentration of PCDD/Fs and Co-PCBs were ranged from N.D.~5.12 (mean value: 0.88) pg I-TEQ/g-d.w and N.D.~0.58 (mean value: 0.09) $WHO_{2005}$-TEQ pg/g-d.w. respectively. The upstream indicate the highest concentration and as it goes to the downstream, it has tendency to decrease. Higher chlorinated compounds were dominant in most of site which detected PCDD/Fs. Occurrence of Co-PCBs isomer patterns appear similar to each sampling site was found. The isomer patterns showed similar between sediment and PCB products. The principal component analysis also showed that the samples contained the characteristics of PCBs products.

• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.173-181
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• 2016

From 2016, controls on reduction of NOx and SOx emissions from the vessels that are operated in the emission control area were tightened. The selectivity catalytic reduction system of the denitrification equipment which NOx among the above controlled materials is very effective and used commercially very much. But it has the disadvantage that CSR is activated at high temperatures. Therefore, the SCR and SCR activation instrument that can react even at low temperatures by using micro-nano bubbles so that the above problems can be minimized were developed. And the computational fluid dynamics technique was used by ANSYS-CFX package to prepare the plan that improves the SCR system's efficiency. Simulation for the viscous flow analysis of the SCR system was executed by applying the Navier-Stokes equation to it as a governing equation. For the SCR system's shape, 3D modeling was done by using CATIA V5. SCR jet nozzle's position was checked by changing it to the intervals of 1/3, 1/2, and 2/3 from the inlet of the vent pipe to compare the SCR system's efficiency. And the number of nozzles was compared and analyzed by simulating 4, 6, and 8 holes to check an effect of the number on the SCR system's efficiency. The simulation result has found that the closer nozzles are to the inlet of the vent pipe and the more nozzles are, the more efficiency is improved.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.5-14
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• 2017

Korea, which has undergone a rapid urbanization, faces various problems such as the management of facilities, safety, environment and transportation. To solve civil complaints, local governments receive electronic complaints, but complaints are increasing. Therefore, this study conducted the spatial distribution pattern analysis and the trend analysis by presenting location data on spatial information through Geo-coding by collecting electronic civil petition data over the last 10 years targeting Jinju city. Using the ARIMA model, this study predicted the occurrence of complaints over the next two years (2016~2017) through a time series forecast analysis. As a result, the complaints related to illegal parking were the highest, the complaint related to noise was the second highest, and the complaints related to illegal garbage dumping was the third highest. In addition, the analysis of the spatial distribution pattern shows that the largest hot spot was formed in the central commercial district every year. As a result of the time series forecasting analysis for the crackdown of the illegal parking, complaints increased slightly. To compare the predicted value and the actual data showed a similar pattern. It is judged that this study will be utilized to establish effective countermeasures against civil complaints.

• Journal of Life Science
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• v.30 no.5
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• pp.411-419
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• 2020

The development of GM crops has gained significant economic importance, and the number of countries cultivating commercial GM crops has continuously increased since the 1960s. Globally, the area given to cultivating GM soybean, maize, cotton, and canola alone had reached 114 million hectares by 2007. Although the economic importance of cultivating and commercializing GM crops has increased, there is still a need to assess their agricultural traits in comparison to non-GM produce. This study evaluated the agricultural traits of GM rice containing the drought-tolerant gene CaMsrB2 and standard rice to investigate any unintended effects of genetic engineering. The GM and non-GM rice were compared in terms of various agricultural traits in a drought greenhouse and an irrigated paddy field. There was no statistical difference in the field-grown crops, but there was a statistically significant difference in both tiller number and yield in the greenhouse. These results therefore suggest that GM rice lines containing the CaMsrB2 gene are superior in performance to non-GM rice in drought stress conditions and could be grown in drought-prone areas where drought intolerant rice may not be able to grow.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.103-115
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• 2018

The potential competitiveness for new routes and resources has been theoretically discussed with regards to the Arctic route but is gradually becoming a reality as global warming increases. In June of 2017, China officially included the Northern Sea Route (NSR) as part of the Belt and Road Initiative (BRI), and major countries' interests in the NSR are greatly expanding. This paper presents the general characteristics of the NSR, NSR development in China, the expected relationship between the NSR and the BRI, and this relationship's implications for Korea. The NSR has poor facilities and information infrastructure and is not economically viable for commercial navigation due to its high-cost conditions compared to competitive routes. In order to explore the Arctic and develop the NSR, large-scale projects must be funded over a long period of time; this has caused major difficulties in development. However, as the NSR is included in the BRI, there could be an opportunity to utilize BRI funds, such as Asian Infrastructure Investment Bank (AIIB). Further, China's NSR development and the NSR development of partner countries, such as Korea, should be further stimulated. As Korea has strengths in terms of its shipbuilding technology and geographical location, which is located at the core of the NSR, Korea would have chances to expand the economic cooperation and business opportunities with China and Russia.

• 대한공업교육학회지
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• v.36 no.1
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• pp.95-114
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• 2011

The purpose of this study was to review and synthesize the papers in cooperation between industries and specialized high schools. We also try to provide explicit directions and suggestions for future researches. A total of 196 studies, including master's and doctoral theses up to 2010, were collected through RISS(Research Information Sharing Service), KISS(Koreanstudies Information Service System), and DBPIA(special database for domestic research information). The results were as follows. The number of papers has been increasing steadily. In the area of research, the field research was the most popular area. The most common type of the research was survey research and library research was followed. Similarly, questionnaire was the most popular method. Technical high schools were the most popular object of studies in specialized high schools. GyeongGi province was the most popular region of studies and Seoul was followed. The most common type of cooperation between industries and specialized high schools were actual training. The students in specialized high school was the most popular object of surveys, and teachers and industry people were followed.