• 한국ITS학회 논문지
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• 제18권5호
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• pp.49-63
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• 2019

지하철 승강장의 혼잡도 관리는 열차지연방지, 승객안전 등의 서비스수준 향상을 위해 중요하다. 승강장 혼잡개선정책을 효과적으로 수립하기 위해서는 혼잡수준을 정확하게 추정하는 방안이 필요하다. 현재 지하철 승강장 혼잡도는 1-2년 주기의 특정 장소 및 시간에 계수방법(Hand Count)로 측정되어 시공간적 제약이 존재한다. 한편 스마트카드자료는 매일 실시간 생성되는 빅데이터 자료로서 승강장혼잡 추정을 위한 기초자료로서 적합하다. 본 연구는 카드자료를 승강장 혼잡도를 동적으로 추정하는 모형을 제안한다. 연구는 우선 혼잡도를 지하철 네트워크를 동적으로 이동하는 승객이 승강장에 집중하는 수요개념으로 정의한다. 이를 위해 지하철 네트워크에서 개별승객이 동적으로 이동하는 궤적을 모형을 통하여 파악한다. 또한 지하철승강장에 집중 및 분산되는 승객흐름을 1분 단위로 산정한다. 마지막으로 승강장구조별 단위 실용대기면적에 따른 승강장 혼잡도를 계산한다.

• 무역학회지
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• 제46권4호
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• pp.189-204
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• 2021

The fourth industrial revolution is affecting the industry as a whole, and the current logistics industry is coexisting with crises and opportunities. As part of overcoming this situation, the online platformization of the logistics market has recently been rapidly taking place, and the growth of e-commerce around developed countries has emerged as a demand for flexible freight services that can send and receive cargo anywhere and anytime at appropriate cost. However, the logistics industry has not been able to change rapidly in line with the demands of the market as it is immersed in traditional transportation transactions. Thus, the digital transformation of the freight market has become urgent to address problems such as uncertainty over traditionally closed and conservative freight market transaction processes and the lack of reliability caused by information asymmetry. Therefore, innovative domestic and foreign companies are attempting to establish a new way of transporting cargo, especially a marketplace way of connecting suppliers and consumers. Current status analysis and case studies were conducted through existing literature surveys, and prior research on freight market place selection factors was previewed, and the selection factors were stratified into five upper and 19 lower factors. Through this study, it is expected that improvements for sustainable growth of freight marketplace companies will be derived and that it will be a basic study of establishing management strategies through marketplace operation and quality control. In addition, it is deemed that the priority of customer requirements can be actively accepted, providing an opportunity to actively respond and strengthen corporate competitiveness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권8호
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• pp.2253-2280
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• 2024

In the upcoming era of transportation, a groundbreaking technology, known as vehicle-to-everything (V2X) communication, is poised to redefine our driving experience and revolutionize traffic management. Real-time and secure communication plays a pivotal role in V2X networks, with the decision-making process being a key factor in establishing communication and determining malicious nodes. The proposed framework utilizes a directed acyclic graph (DAG) to facilitate real-time processing and expedite decision-making. This innovative approach ensures seamless connectivity among vehicles, the surrounding infrastructure, and various entities. To enhance communication efficiency, the entire roadside unit (RSU) region can be subdivided into various sub-regions, allowing RSUs to monitor and govern each sub-region. This strategic approach significantly reduces transaction approval time, thereby improving real-time communication. The framework incorporates a consensus mechanism to ensure robust security, even in the presence of malicious nodes. Recognizing the dynamic nature of V2X networks, the addition and removal of nodes are aligned. Communication latency is minimized through the deployment of computational resources near the data source and leveraging edge computing. This feature provides invaluable recommendations during critical situations that demand swift decision-making. The proposed architecture is further validated using the "veins" simulation tool. Simulation results demonstrate a remarkable success rate exceeding 95%, coupled with a significantly reduced consensus time compared to prevailing methodologies. This comprehensive approach not only addresses the evolving requirements of secure V2X communication but also substantiates practical success through simulation, laying the foundation for a transformative era in transportation.

• 한국해양환경ㆍ에너지학회지
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• 제6권4호
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• pp.3-12
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• 2003

지속적인 산업화와 도시화에 따른 에너지 수요의 급증으로 인해 원유와 석유제품의 해양수송이 점점 증가하고 있다. 우리나라의 경우 국내의 유류 수요를 맞추기 위해서는 매일 30만톤급의 대형 유조선이 입항해야 하기 때문에 대형 유류오염 사고에 노출되어 있다 해양 유류오염사고의 가능성을 줄이기 위해 부단한 노력에도 불구하고 회복하기 어려운 유출 사고는 인간의 실수, 악천후 또는 복합적인 이유로 일어나게 된다. 따라서 적절한 대응시스템으로 지역방제계획을 세워 최악의 경우에 대비하고 해양환경과 연안자원을 보호해야만 한다. 특히 보호의 우선순위를 명확히 하고 현장 방제전략을 세움으로써 유출과 방제의 노력이 환경에 미치는 영향을 줄이기 요구되는 방제정보지도에 초점을 맞추었다. 본 논문에서는 기름에 대한 민감도의 정의와 개발한 소프트웨어의 주요특짚과 함께 방제정보지도를 간략히 소개한다.

• 아태비즈니스연구
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• 제9권2호
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• pp.105-121
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• 2018

In 1995, the WTO started to ease the trade barriers. Globalization has accelerated. The opening of the agricultural products market is rapidly gaining momentum with the conclusion of an FTA. The acceleration of this FTA is expected to be a threat to Korea's agriculture, and a new strategy is needed. At the beginning of the nuclear accident, mainly radioactive materials are found in the surface layer of the soil. Over time, the concentration of the plant gradually increases. After 5 years, it becomes noticeable. In March 2016, it will be five years after the nuclear accident. Radioactive contamination is very likely to occur in agricultural products produced in the Fukushima area at this time. In this period, agricultural products produced in the Fukushima region are expected to generate supply disruptions in Japan, and imports to replace them will increase. Therefore, it is necessary to establish a mid- and long-term strategy for exporting to Japan by analyzing the competitiveness of Korean agricultural products. In this study, standardization index was derived by using agricultural price ratio, TSI, export CAC. Based on this, we analyzed the competitiveness of each item in the Japanese market. The analysis shows that garlic is the most competitive product in the Japanese market. Also, strawberry, tomato, and cucumber were found to be competitive. On the other hand, Kiwi, pineapple, soybean, onion, potato, etc. As a result of the analysis, the following strategies were proposed for the export of agricultural products with high competitiveness. First, it is necessary to develop technology to suppress deterioration of export transportation quality. Second, continuous supply of local consumption pattern information is required. Third, it is necessary to expand exports by processing fresh food. Fourth, it suggested the establishment of export base and strengthening of support system.

• 대한토목학회논문집
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• 제33권3호
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• pp.1087-1094
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• 2013

본 연구는 자동차 배출가스에 의한 대기질의 사회적 비용 추정 결과의 객관성 향상을 목적으로, 일 단위, 첨두 비첨두 시간단위, 각 시간 단위별 대기질의 사회적 추정 방법 차이가 그 결과에 미치는 영향을 살펴보고 그 시사점을 도출하였다. 분석결과, 대기질의 사회적 비용은 분석 시간대에 따라 약 24배까지 차이가 발생하는 것으로 나타났으며, 일 단위와 각 시간 단위 통행배정에 따른 대기질의 사회적 비용은 연 평균 약 6,536억원의 차이가 발생하는 것으로 나타났다. 한편 첨두 비첨두 단위와 각 시간 단위의 통행배정에 따른 추정 결과는 약 1%의 차이가 발생하지 않는 것으로 나타났다. 본 연구를 통해, 대기질의 사회적 비용은 통행배정 방법론에 따라 큰 차이가 발생한다는 점을 확인하였고, 특히 CAPSS의 방법보다 시간대 분석이 가능한 교통수요분석 기법에 의한 배출량 및 대기질 비용 추정방법이 보다 정확도가 높음을 입증할 수 있었다. 아울러 대기질 개선을 위해, 시간대별 교통수요관리의 필요성을 확인할 수 있었다.

• 한국농촌생활과학회지
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• 제4권2호
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• pp.127-137
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• 1993

This survey was carried out in order to find out the education needs of rural women in home improvement. The data were collected from 500 samples who were conjugal women under 65 years old by adminitrating the researcher developed questionaire through interview method. This interview was intensively focused in education fee, free or charged. The major findings of the survey were summerized as follows ; 1) In the educational fee is free, $\ulcorner$fatigue recovery$\lrcorner$ is demanded highest(61.7%) and $\ulcorner$wrighting art$\lrcorner$ is lowest among 30 items. The needs of education are devided 7 fields of the home improvement $\ulcorner$dietary life$\lrcorner$ is the highest demand fields among them. 2) If educational fee is charged, the item of $\ulcorner$technique for side job$\lrcorner$ was highest(42.2%) but $\ulcorner$selecting clothes$\lrcorner$ was lowest, And the field of $\ulcorner$home management$\lrcorner$ was highest demands. 3) On the overall needs of education, charged and free, they want the item of $\ulcorner$family nutrition management$\lrcorner$ and the field of $\ulcorner$dietary life$\lrcorner$ was selected highest. 4) In the relationship between needs of education items and individual/household variables, i.e. age, degree of education, life philosophy, hobby, social activity, experience of home improvement education, and transportation convenience, had significant relationship at 5% level. And the relationship of $\ulcorner$dietary life$\lrcorner$ and $\ulcorner$home management$\lrcorner$ fields are higher significant with individual/household variables.

• 품질경영학회지
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• 제46권4호
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• pp.899-910
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• 2018

Purpose: Generally, since the population density is lower in suburban areas, the distance to school is inevitably long. Therefore, schools in suburban areas often operate school buses to improve student welfare. However, since school buses are usually used only during going to and from school, the utilization rates are relatively low. Therefore, this study aims to establish integrated operation plan of public school bus covering all schools. Methods: It is necessary to decide which school buses will serve the specific demand node which want to go to certain school in order to design an integrated operation plan for school buses. Therefore, a mathematical model is developed for minimizing the total number of vehicles and the distance of transportation by reflecting the characteristics of school buses and students as constraints. To solve the proposed mathematical model, CPLEX, a commercial solver, is applied. Results: To validate and to confirm the proposed process, numerical example is designed with the comparison between before and after integrated operations of school buses in terms of total operation cost. The result shows that the integrated operation can lead the reduction of the number of school buses as well as the decreasing of the fuel cost. Conclusion: This study provides the quantitative method to perform the integrated operation of school buses in suburban areas. The optimal operation strategy is required because there are more complex decision-making elements considering the integrated operation. It is expected to apply this research result at real situation to expand this services based on an optimal operation.

• 한국인터넷방송통신학회논문지
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• 제21권1호
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• pp.189-194
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• 2021

최근 1인 가구의 비율이 높아짐에 따라 2016년을 시작으로 전동킥보드, 전동 휠 등 국내 공유형 퍼스널 모빌리티(Personnel Mobility) 시장이 급성장하였다. 전동킥보드와 같은 개인 형 이동수단은 전기를 사용한 동력장치로 친환경이고, 가벼우며 별도의 주차공간을 차지하지 않는다. 무엇보다 중단 거리를 이동하기에 편리하다는 장점이 있어 합리적인 소비를 추구하는 젊은 층 사용자들의 많은 수요를 얻을 수 있었고, 이에 따라 관련 시장이 빠르게 성장하였다. 하지만, 전동킥보드의 충전스테이션 부재로 사용이 완료된 전동킥보드들이 도로 곳곳에 방치되며 미관상뿐만 아니라 안전상의 위협요인으로 대두 되고 있다. 이에 본 논문은 공유 형 전동킥보드의 효율적 회수를 위한 새로운 IoT 관리 시스템을 연구하고, 제안하고자 한다. 이러한 시스템을 통해 전동킥보드의 높은 회수율을 유지하고, 결론적으로 사용자와 주변 환경의 안전성 향상을 도모할 수 있을 것으로 기대된다.

• 한국환경과학회지
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• 제14권9호
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• pp.835-842
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• 2005

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0 -0.50 mg/m2/day. The net decomposition rate of COD was 0 -0.04 mg/m2/day in middle level(3 -6m) and 0.05 -0.1 5 mg/m2/day in bottom level(6m -bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.