• 한국항만경제학회지
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• 제25권2호
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• pp.247-258
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• 2009

본 논문에서는 우리나라 철도운송 서비스의 활성화 방안을 강구하기 위한 방안으로 기존 철도화물 이용자를 대상으로 철도화물 선택에 관한 요인분석을 시도하였으며 기존 이용자들의 설문조사를 통해 이들 요인들에 대한 우선순위에 대한 실증분석을 AHP분석을 통해 추진하였다. 철도화물 이용 하주들의 화물운송 서비스에 대한 선택요인 요인으로는 운송우위성 > 운송안전성 > 물류연결성 > 정보연계성의 순으로 나타났으며 이의 하위계층에 해당하는 요인들의 우선 순위는 운송시간/비용절감 > 화물의 안전운송 > 정시성 > 탄력적 대응 > 타 수단 연결성 > 운송화물 취급 적합성 > 대체수단 부재 > 환적 용이성 > 정보제공의 순으로 나타났다. 결론적으로 시간과 비용적인 측면에 대한 중요성이 제일높고 정보나 환적 및 대체수단에 대한 고려가 상대적으로 낮다는 것은 우리나라의 철도화물 운송서비스가 다른 운송서비스의 발전 속도와는 달리 아직까지 초보적인 운송서비스를 제공하는 수준에 머무르고 있다는 것을 반영하고 있다는 것임을 추론 할 수 있다. 효율적 철도화물 운송서비스 구축을 위해서는 우선적으로 운송시간 및 비용절감과 화물운송 서비스의 정시성 구축 방안이 우선적으로 검토되어야 할 것이다. 또한 운송비용의 절감을 위해서는 철도화물의 특성인 대량운송을 통한 비용 절감의 효과를 더욱 확대할 수 있는 방안도 강구되어야 할 것이다. 특히 대량운송을 위한 "고속장대화물열차"의 운행도 적극 검토되어야 할 것이다. 국내 철도는 타 운송수단과는 달리 장기적인 독점 공급자에 의한 독과점적 시장구조를 지니고 있으므로 보다 효율적인 운송서비스 공급을 위해서는 정기적이고 지속적인 이용자들의 수요조사를 통해 화물열차운행에 즉각적으로 반영할 수 있는 이용자중심의 마케팅 전략수립으로의 전환도 필요할 것이다. 또한 우리나라 철도는 노선별로 화물운송에 대한 서로 다른 특성을 가지고 있으므로 노선별, 화물별 이용자의 서비스 선택요인을 분석함으로써 보다 세부적이고 구체적인 화물 운송수요에 대한 분석에 대한 연구가 추진되어야 할 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.614-620
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• 2011

Railway intelligent transportation systems and related Ministry of Land and rail operating agency's railway informatization planning of information technology, effective through the use of management strategies to establish or run to support the systematic informatization investment that you want to execute work in progress, during and yet the institutional informatization of operations mainly in the form of efficiency is Chinhae. Accordingly, in order to promote the details of the final challenge of providing real-time information and the usefulness of this information collection is clearly for the railway sector by function of the components is necessary to distinguish. In this paper, the details of the plan goals, promoting convenient rail-based real-time information, to promote optimal gohyoeuleul railways, railway safety and comfort, was defined as three. Selection of each goal, because the direction of vision and ITS around the railroad center of road users by highlighting the benefits of the railroad's traffic information center user switching, real-time delivery of information diversity (enhanced content) that can increase the capacity of line train operating systems, enhancing the safety management system introduced in the monitoring system and is a railroad crossing. Because urban railway project in accordance with the goal of decreasing the annual rate of the train support, and the average passenger wait time savings, increased future demand for railway, rail safety, including securing the expected effects may occur.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4242-4263
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• 2017

Multi-User Multiple-Input Multiple-Output (MU-MIMO) technology has recently attracted significant attention from academia and industry because of it is increasingly important role in improving networks' capacity and data rate. Moreover, MU-MIMO systems for the Fifth Generation (5G) have already been researched. High Quality of Service (QoS) and efficient operations at the Medium Access Control (MAC) layer have become key requirements. In this paper, we propose a downlink MU-MIMO MAC protocol based on adaptive Channel State Information (CSI) feedback (called MMM-A) for Wireless Local Area Networks (WLANs). A modified CSMA/CA mechanism using new frame formats is adopted in the proposed protocol. Specifically, the CSI is exchanged between stations (STAs) in an adaptive way, and a packet selection strategy which can guarantee a fairer QoS for scenarios with differentiated traffic is also included in the MMM-A protocol. We then derive the expressions of the throughput and access delay, and analyze the performance of the protocol. It is easy to find that the MMM-A protocol outperforms the commonly used protocols in terms of the saturated throughput and access delay through simulation and analysis results.

• 한국조경학회지
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• 제33권2호
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• pp.83-91
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• 2005

The purpose of this study is to analyze the arrangement of parks, in whole city level by using park's effective distance and to find the accessibility obstacles in case of using parks, in boundary of each parks' effective distance, so that to show how to improve communities' usage of city parks. The 8 cities in Gyeonggi-do and analysed the effective distance of parks. To find the accessibility obstacles in the boundary of parks' effective distance, 1) we choose 18 sample parks and extract obstacles - wide road, rail road, river- in interior and verify it by field survey and asking the park user's residents directly. The main findings of this study can be summarized as follows: First, Ansan city and Goyang city are only satisfied with the minimal city parks size standard, so that the rest 6 cities are lack of quantities which residents can use. The result of analyzing effective distance in whole city level, parks are mainly designated in new-town, so that most cities which have old-towns have very poor park systems to use. Because Ansan city is new-planned city, it is very effective arrangement in park systems exceptionally. Second, $96.2\%$ of park users' are living in the area which was easy to gain access not intercepted by wide road, rail road or river. Third, therefore at the stage of planning park, effective distance and resident's accessibility as well as park's supply quantitatively are needed to be considered. In addition, selection of location and elevation of resident's safety and accessibility through making a plan must be reflected. In the low accessibility area, the program to improve park's accessibility and amenity - like making small park or pocket park, linking parks with resident-friendly road etc.- has to be investigated.