• 대한교통학회지
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• 제24권5호
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• pp.45-56
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• 2006

우리나라 철도산업의 생산특성과 효율성에 관하여 충분히 검토된 양질의 정보가 축적되기 위해서는 다양한 각도에서 다양한 방법으로 검토가 필요하다. 본 논문에서는 거리함수를 이용한 우리나라 철도산업의 생산특성 및 기술효율성 분석결과를 제시한다. Shephard(1953)가 처음 소개한 거리함수는 가격에 관한 정보를 필요로 하지 않는다. 따라서 가격에 관한 자료를 구하기 어렵거나 또는 공공부문의 경우처럼 가격에 대한 통제가 존재하는 상황에서 효과적인 분석수단이 될 수 있다. 또한 다수투입 다수산출 생산기술을 다룰 수 있으며 생산특성과 효율성을 동시에 분석할 수 있는 장점을 갖고 있다. 한국철도의 1963년부터 2004년까지의 연도별 자료로부터 이차계획법모형을 사용하여 거리함수를 추정하였다. 추정된 기술효율성은 1980년 이후 2004년까지 점진적으로 개선되고 있는 것으로 나타났다. 간접 Morishima대체탄력성 추정결과는 노동을 다른 투입으로 대체하는 것이 매우 어렵거나 또는 불가능한 것으로 나타났다. 평균 규모탄력성은 2.7로 나타났으며 이는 규모를 1%증가시켰을 때 산출이 2.7%증가함을 의미한다. 즉 한국철도에 규모의 경제가 존재함을 의미한다.

• 한국주거학회논문집
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• 제20권4호
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• pp.79-88
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• 2009

A planned access method on constantly-changing-community unit plan changes and develops based on the periodical situation and also plan theory. In this research, it is to present the link between the theory of complex city change and the plan factor of it, and to show how Korean residential complex plan has changed as time passed and how new concept of city plan came up and by applying new methods how can this affect our real world and the past plan. In the phase of analysis, it analyzed the flow of 'community unit plan' and its theory and investigated the factor of compositional space and built a analysis frame. The factors of community unit plan are space structure, size and shape of block, population, distribution of facilities and movement system. It chose the place that can represent the flow of community unit plan trand and that indicates the obvious development leading to Jamsil (1975), Gwa Chun (1980), Mok Dong (1983), Sang Ge (1985), Ilsan (1989), Dong tan (2001) and Eun Jung (2003) total of 7 places. And to compare a similar size of the city, it selected a small community unit. Based on the result of theoretical study and prior research, it can be said that the space composition style has change from a whole complete complex area to a linked-cross over community unit and the access of urban level was on set. Also, a pedestrian walking area was secured and the dense of building structure and pleasant environment wanting need was in balance. For facility plans, the usage of facility and functional change brought change of type, size and disposition. The walking area for pedestrian became a huge matter. Therefore, market, education, public facilities and green system collaborated to co-build a whole community unit and activated the walking environment. Also, public transportation, environment friendly city organization was built.

• 한국융합학회논문지
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• 제10권5호
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• pp.181-188
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• 2019

ICT기술을 기반으로 공유경제 서비스시스템을 사람들이 손쉽게 사용할 수 있다. 대부분의 공유경제 서비스는 민간기업에서 제공하고 있으며, 공공재에서의 논의는 미진하다. 현재 진행되는 공유경제 서비스를 택배서비스 관점에서 본다면 우버의 시스템이 대안이 될 수 있다. 우체국의 택배서비스는 ICT기술을 이용하지만 공유경제의 서비스와는 차이가 있다. 본 연구는 델파이 분석기법과 AHP방법론을 사용하여, 공유경제 시스템을 도입하는데 있어서 중요요인들을 도출하였다. 그 결과 상위계층에서는 사회경제적 특성이 가장 중요한 것으로 나타났으며, 하위계층에서는 공유경제 플랫폼, 유휴자원의 공유, 스마트폰의 대중화, 전자상거래의 증가가 4가지 중요 요인임을 알 수 있었다. 이 연구를 통해서 공유경제의 본질인 '효율의 극대화'를 위해서 공공재에 공유경제 시스템에 도입의 필요성과 도입 시 중요요인에 대해서 제시하고 있다.

• 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.

• International Journal of Automotive Technology
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• 제2권2호
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• pp.39-45
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• 2001

Hydrogen is seen as one of the important energy vectors of the next century. Hydrogen as a renewable energy source, provides the potential for a sustainable development particularly in the transportation sector. Hydrogen driven vehicles reduce both local as well as global emissions. The laboratory of transporttechnology (University of Gent) converted a GM/Crusader V-8 engine for hydrogen use. Once the engine is optimised, it will be built in a low-floor midsize hydrogen city bus for public demonstration. For a complete control of the combustion process and to increase the resistance to backfire (explosion of the air-fuel mixture in the inlet manifold), a sequential timed multipoint injection of hydrogen and an electronic management system is chosen. The results as a function of the engine parameters (ignition timing. injection timing and duration, injection pressure) we given. Special focus is given to topics related to the use of hydrogen as a fuel: ignition characteristics (importance of electrode distance), quality of the lubricating oil (crankcase gases with high contents of hydrogen), oxygen sensors (very lean operating conditions), noise reduction (configuration and length of inlet pipes). The advantages and disadvantages of a power regulation only by the air to fuel ratio (as for diesel engines) against a throttle regulation (normal gasoline or gas regulation) are examined. Finally the goals of the development of the engine are reached: power output of 90 kW, torque of 300 Nm, extremely low emission levels and backfire-safe operation.

• 농촌계획
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• 제28권2호
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• pp.11-20
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• 2022

As a portal to rural town, Myeon near large cities is expected to represent image of the rural area. But, the landscape are changing rapidly due to development pressure and to the expansion of the transportation network. For visitors and transit traffic, Recognizing that the characteristics of the streetscape is an important task for the vitalization of the rural district. In particular, it was found that the visual quantity of the central street in the location of the town was closely related to the preference of the streetscape, and the visual quantity of trees and the visual quantity of the building showed an inverse relationship of + and - respectively. Since this is not a simple ratio of the sky to the building, but a relative factor, the possibility of landscape improvement can be improved through management of public facilities or green spaces and maintenance of open spaces or gaps between buildings. It seems that it is necessary to secure separate means for the management of the architectural landscape, such as the establishment of a special landscape plan or establishment of ordinances.

• 한국안전학회지
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• 제29권1호
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• pp.80-85
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• 2014

A survey of risk perception in South Korea was conducted in 2007 to evaluate relative riskiness of typical industrial and technological risks. This article summarizes the characteristics of risk perception using psychometric analyses. The survey with a sample size of 1,194 reviews the perceived level of 25 risk items in the areas of transportation, chemicals, environment, industry, nuclear power generation, and newly-introduced risks. Six categories of risk identified by a factor analysis show that the level of perceived risk does not correspond to the statistical level. Psychometric analyses including voluntariness, severity, effect manifestation, exposure pattern, controllability, familiarity, benefit and necessity demonstrate that voluntary, familiar and immediate risks are perceived as less risky than involuntary, unfamiliar and delayed ones. Risk communication is critical in reducing the discrepance between objective and subjective level of risk. However, the amount of risk information does not always justify a successful risk communication. A safety policy, risk communication strategy in particular, should take into account diverse dimensions of risk reviewed by psychometric analyses in the study. Social policy toward safety can be improved by integrating policy, human, and social factors as well as technological advances.

• 한국도로학회논문집
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• 제19권4호
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• pp.9-18
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• 2017

PURPOSES : This study evaluates the reasonableness of the recommended amount of deicing chemicals based on historical data for snow removal. The result can be used to aid decision-making for the reservation of cost-effective de-icing chemicals. METHODS : First, the recommended amount of de-icing chemical to use and historical usage data were evaluated to identify specific usage characteristics for each region. Road maintenance length and snow-removal working days were analyzed over the past five winter seasons. Next, differences in the recommended amount of chemical to use and actual use were compared using the Kolmogorov-Smirnov test. Last, the two types of data were analyzed using a chi-square test to verify if the two distributions of variation pattern are statistically significant. We found that there are significant differences between the data from each region during the past five winter seasons. RESULTS : The results showed that the equation for calculating the amount of de-icing chemical to use appears to be revised. CONCLUSIONS : The results imply that the equation for calculating the amount of de-icing chemical to apply as a national standard is very important when the public agency makes decisions related to snow-removal.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.167-172
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• 2002

Seoul subway system has been constructed to solve traffic difficulties of Seoul metropolitan, and now is the major public transportation. However, the more line has added in the system the deeper the bottom of the tunnel base. And a huge amount of groundwater along the line has seeping into the tunnel. Several subway stations has pumping system to extract the groundwater to the outside and consequently, groundwater table along the line has declined gradually. Groundwater table has dropped about 40 meters at some areas, There was some study for the proper usage of the abstracted groundwater and the project to use the groundwater has launched already by the local government. However. more serious problem is expected on quality degradation of soil and groundwater as the decline of groundwater table along the subway line. This study suggests that the detailed groundwater environmental study should be made as soon as possible for this. If there is any pollution leaking at the surface area of the groundwater depression, the pollution will be seep into the subway tunnel in some day even though the time will be different with the soil material and hydraulic characteristics of the aquifer. And the polluted area of the soil and groundwater would be enlarged along the pathway The study on possibility of the soil subsidence and reducing surface water flow in small creek were also needed. This study suggest one of the counter measurement that restoring the declined groundwater table after groundwater environmental study

• 한국컴퓨터정보학회논문지
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• 제15권8호
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• pp.173-180
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• 2010

본 연구의 목적은 지능형 교통체계에서 유비쿼터스 센서 네트웍(USN: Ubiquitous Sensor Network)의 융합기술을 활용하여 자전거 시설물의 보안과 안전 기능을 향상하는데 있다. 이러한 목적을 달성하기 위해서 유니버셜 센서 네트웍 기술을 활용하여 U-bike 시스템을 개발하였다. 자전거도로 시설물 안전에 대한 문헌연구를 통하여 유비쿼터스 자전거 교통정보와 서비스 특성을 분석하여 USN을 활용한 자전거 및 시설물의 안전 인프라 구축 방안을 제시한다. 본 연구결과는 4대강 자전거도로 및 시설물 안전성능을 향상하는데 기여할 것이다.