• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.133-143
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• 2014

The paper uses a panel gravity model to analyse the determinants of export via Gwangyang port for the period from 2000-2012. The gravity model includes export via Gwangyang port, GDP and population of trading partners, the distances between Korea and its partners, and Korea-ASEAN FTA dummy. Hausman test shows up which one is exactly appropriate between random effect estimation and fixed effect estimation to use panel dataset. It depends on whether or not existence or nonexistence of the correlation between unobserved omitted factors and variables. Fixed effect estimation is suitable for this paper by the rejection of null hypothesis. An Empirical analysis of this paper shows GDP influences positive effects and distance influences negative effects to Gwangyang port trading partners. In addition, the results strongly supported the effects of Korea-ASEAN FTA on the growth of Gwangyang port export.

• Journal of the Korean association of regional geographers
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• v.8 no.1
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• pp.98-109
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• 2002

The long term land-cover changes and the pattern of morphological changes in foredune ridges and unvegetated dunes were investigated for about 30 years through analysing aerial photographs in Shinduri coastal dunefield, Korea. As a result, forested dune area increased while unvegetated dune area decreased continuously since 1967. Foredune ridges retreated landward about 80m away from the former coast-line in the middle part while they advanced seaward after construction of dike in the northern part during last 3 decades. Unvegetated dunes in the middle part of the dunefield were eroded at seaward side and moved landward away. These facts mean not only coastal dune area has been affected by man-made effects such as afforestation and coastal developments but also shinduri coastal dune area has been stabilized by plants and has been negative sediment budget.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.786-793
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• 2020

The purpose of this study is to analysis the horizontal distance of COM and COP and the movement patterns of COM and COP during the badminton high-clear of woman middle school student. The select variables used in the statistical analyses(independent sample T-test) were the horizontal distance of COM and COP at (E4), and the maximum COM displacement of the back-, forward-, whole-swing phases between expert and novice groups. Based on the results in this study, it was concluded that: First, expert group showed the shorter horizontal distance between COM and COP in anteroposterior axis (X-axis) at Event 4 compared to the novice group. Second, expert group dominantly used COM vertical movement while novice group actively used COM horizontal movement during the badminton high-clear stroke.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.195-201
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• 2017

As of 2016, the total traffic usage of handicapped people were 24.8%. Buses (25.6%) have the highest rate of travel, with the exception of "walking (33.5%)" as the main means of transportation for these handicapped people. Therefore, the Seoul Metropolitan Government expanded the low-floor bus, which is a means of transportation for the underbelly, to 30% by 2015, but the satisfaction level of mobility improvement of the underbelly was only 2% To 55%. In fact, increasing the percentage of low-floor buses is merely a superficial solution, and there are many restrictions on solving fundamental problems with limited budgets. Therefore, in this study, we use statistical analysis R, with a simple data manipulation and visualization function, to grasp the living area and life pattern of handicapped people in Seoul city.

• Journal of Cadastre & Land InformatiX
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• v.52 no.2
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• pp.153-169
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• 2022

With the extension of the average life span and the rapid aging of the population, defining elderly population as a single group is difficult as the physical, economic and social conditions of individual have become different. Therefore, policies that take into account the characteristics of each group are required. The purpose of this study is to classify individual travel types and to analyze the characteristics of each travel type, based on individual public transportation trajectory data as known as smart card data. Among the four classified types, the long-distance low-frequency stay type and the short-range medium-frequency mobile type show external activity traffic characteristics for retirement leisure, while the long-distance high-frequency stay type and the long-distance high-frequency mobile group include regular commuting. Traffic variability and residence areas of stay were identified in terms of each classified travel type. The results of this study provide the important suggestions for establishing a transportation policy that takes into account the characteristics of each type of elderly population in Seoul.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.7-15
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• 2010

Research of this paper focused on developing and demonstrating of algorithm with the figures of difference between historical traffic pattern data and real-time traffic data to decide on what the incident is. The aim of this dissertation is to develop incident detection algorithm which can be understood and modified easier to operate. To establish traffic pattern of this algorithm, weighted moving average method was applied. The basis of this method was traffic volume and speed of the same day and time at the same location based on 30-second raw data. The model was completed by a serious of steps of process-screening process of error data, decision of the traffic condition, comparison with pattern data, decision of incident circumstances, continuity test. A variety of parameter value was applied to select reasonable parameter. Results of application of the algorithm came out with figures of average detection rate 94.7 percent, 0.8 percent rate of misinformation and the average detection time 1.6 minutes. With these following results, the detection rate turned out to be superior compared with result of existing model. Applying the concept of traffic patterns was useful to gain excellent results of this study. Also, this study is significant in terms of making algorithm which theorized the decision process of actual operators.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.337-346
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• 1992

Hydroacoustic surveys were conducted in the East China Sea, in the summers of 1990-1991 to investigate the distribution and migration behavior of fish, such as the diel changes in the distributions of fish, the thermoselection behavior of fish, and the fish reactions to a surveying vessel. The hydroacoustic observations were taken with a scientific echo sounder operating at 50kHz and a microcomputer-based echo processor. Fish samples were collected by bottom trawling and temperature was measured with a DBT system. The patterns of fish distributions were compared with the vertical profiles of water temperature. The results obtained can be summarized as follows: 1. The time series of hydroacoustic observations on the downward migration at dawn in the central region of East China Sea showed that the migration rate was 0.24 m/min. In this region, most of the fish collected by bottom trawling during the surveys were squid (Photologio edulis f. budo) and horse mackeral (Trachurus japonicus). 2. The hydroacoustic observations, which together associated with temperature data, indicated that squid and horse mackeral concentrated nocturally in a narrow vertical band of thermocline, particularly in summer when the survey region was strongly stratified. This result suggest that the nocturnal vertical distribution of these species evidently is controlled by temperature. 3. When the survey vessel, that is running at a speed of 11 knots, has suddenly stopped, the fish which concentrated beneath the transducer showed a strong avoidance reaction in the form of rapid downward migration. After a few minutes, the descending reaction disappeared and the fish slowly began the upward migration toward their original swimming positions. Trawl data suggest that the fish, which showed the avoidance reaction, was Liparis tessellatus.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.98-105
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• 2021

Understanding the migration patterns and habitats of juvenile birds during the post-fledging stage is very important for conservation and management of individuals. The Chinese Egret is an internationally protected species. During the wintering season, they inhabit South-East Asia, such as the Philippines, Malaysia, and Taiwan, and breed in China, Russia, and uninhabited islands on the west coast of Korea. IIn this study, we attached a GPS telemetry tracking device to six juvenile Chinese Egrets breeding on Chilsan Archipelago in 2018 and 2019 to identify habitats by analyzing the home range during the post-fledging stage in the summer season. The individual CE1801 moved north and then returned to the Yeonggwang Baeksu tidal flat area, and CE1802 and CE1803 migrated north and inhabited Taean-gun. In 2019, CE1901 showed a similar pattern to CE1801, and CE1902 migrated southward to the Wando-gun area, while CE1903 moved south to the Sinan-gun area then returned to the Yeonggwang Baeksu tidal flat area, showing KDE 50%. The study results confirmed that the Chinese Egret moved broadly around the flat tidal area on the west coast to find a stable habitat during the post-fledging stage. Efforts to protect the habitat, such as limiting the development of this area and restricting human access, are necessary.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.831-838
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• 2001

Mobile information service aims to provide some degree of effective information for real life activities of mobile users. Due to the user mobility and actual realism, it becomes very important technical issue to support an adaptive information service methodology to current situations of the terminal and/or user. This paper deals with a prefetching scheme for location-aware, out of the various context-aware which can be considered in mobile information service. It makes use of the velocity-based mobility model to shape the terminal and/or user's mobility behavior. Based on the moving speed and direction, the prefetching zone is proposed to define the number of prefetched information, so as to limit effectively the prefetched information whilst to preserve the location-aware adaptability. Using a simulator, the proposed scheme has been evaluated in the effectiveness point of view. The idea in this paper is expected to be able to extended to the other mobile service contexts, such as service time, I/O types of mobile terminals, network bandwidth.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.67-67
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• 2017

국내의 밭작물 재배에서는 부족한 인력과 시간을 단축하기 위한 농기계 사용이 필수가 되었다. 효율적인 농기계의 개발을 위해서는 농민들의 작업실태 분석이 반드시 선행되어야 한다. 본 연구에서는 감자 재배용 작업기 개발을 위해 전국의 감자 재배 농민을 대상으로 트랙터 작업기 사용실태 조사를 수행하였다. 조사대상은 강원도, 경상북도, 전라남도의 지역중 감자 생산량이 많은 곳을 분류하여 각 지역의 농업기계 대리점에서 추천한 농민을 대상으로 조사표에 의한 방문 면접 설문조사를 실시하였다. 분류된 지역은 강원도 홍천, 평창, 경상북도 고령, 김천, 전라남도 영광, 보성이다. 각 지역별 응답자수는 2명으로 진행하였다. 조사항목은 감자 재배시기, 보유하고 있는 작업기, 트랙터의 모델 및 보유대수, 작업기별 트랙터 주행단수 및 PTO 단수, 작업패턴 등이다. 조사결과, 공통적으로 감자품종 중 수미감자를 선호하는 것으로 조사되었고, 지역별로 시기상의 차이가 있지만 평균적으로 1월~5월과 8월~11월 사이에 감자 이모작을 실시하는 것으로 나타났다. 트랙터의 평균 보유대수는 2대였으며, 평균적으로 중형 트랙터 1대와 대형 트랙터 1대의 비율로 보유하고 있는 것으로 조사되었다. 보유하고 있는 작업기는 로타베이터, 수확기, 시비기, 방제기, 파종기 순으로 보유대수가 많았다. 작업기로 수행하는 밭작업으로는 경운정지, 비닐피복, 시비, 방제, 수확 등이 있었으며, 경운정지용 로터리 작업시 트랙터 주행단수와 PTO 단수는 트랙터의 경우 L2~L3단을 주로 사용하고, PTO의 경우 1단과 2단을 병행하여 사용하는 것으로 조사되었다. 로타베이터 작업패턴은 지역별로 차이를 보였으나, 평균적으로 밭의 모서리를 둘러서 작업하고 이후에 8자형식으로 이동하면서 두둑을 형성하는 것으로 나타났다. 이 작업패턴을 사용하는 이유는 후진을 하지않는 작업환경에서 가장 효율적이고 밭의 모서리에 흙이 모이지 않게하기 위함이라고 하였다.