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        검색결과 292

        161.
        2015.05 구독 인증기관·개인회원 무료
        폴리이미드는 열적·화학적 안정성을 가지고 있으며 다양한 기체인자에 대하여 투과도 및 선택도를 가지고 있다. 그러나 폴리이미드와 같은 고분자 분리막은 실제 공정에 적용되기에는 낮은 투과도를 가져 투과도에 영향을 미치는 주요 요소인 자유체적을 향상시키려는 많은 연구가 진행되고 있다. 본 연구에서는 비대칭구조를 가지는 DOCDA 또는 플루오르기를 가진 6FDA와 강직한 1,5-naphthalenediamine(DAN)를 이용하여 폴리이미드 랜덤 공중합체를 합성하고 DAN이 CO2/CH4 기체투과도 및 분리에 어떠한 영향을 미치는지 확인하고자 하였다.
        162.
        2015.05 구독 인증기관·개인회원 무료
        본 연구는 선행연구된 DOCDA-ODA 와 DOCDA-MDA에 벌키한 메틸치환기를 가지는 다이아민을 추가하여 기체투과도를 향상시키고자 하였다. 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride(DOCDA)는 부분적으로 지환족을 가지고 있는데, 이러한 비대칭구조는 용해성을 향상시킨다. 이와 같은 DOCDA를 m-TDA, p-DMPD, m-TrMPD(50mol%) : ODA 또는 MDA(50mol%)로 하여 one-step법으로 폴리이미드 공중합체를 합성하였다. 합성된 폴리이미드 공중합체는 FT-IR 구조분석을 통해 합성여부를 확인하였고, 여러 가지 물성 분석 및 CO2, O2, N2, CH4에 대한 기체투과도를 측정하였다.
        163.
        2015.04 구독 인증기관·개인회원 무료
        This study presented the analytical safety evaluation of precast modular bridge super-structure, using standardized modular members and robotic construction during the transportation routing and lifting conditions. In order to evaluate the safety performance of the bridge system, linear and nonlinear 3D full scale Finite Element (FE) for 12 m and 16 m standardized modular blocks was developed in ABAQUS and then analytical study was classified into two different structural systems according to steel girder structures: 1) modular bridge block lifting method including the steel girder system; 2) modular bridge block lifting method without the steel girder system. As a result, in analytical study, the results revealed that the maximum stress of each modular member was in maximum allowable stresses, during lifting condition. However, the stress concentration at the connected area was more critical in comparison to the behavior of entire modular blocks both 12 m and 16m, during lifting time.
        165.
        2015.04 구독 인증기관 무료, 개인회원 유료
        Quality of life due to climate change are different and are seeking a way, that affects most of the water seems to be the field. Carbon dioxide is a greenhouse gas causing climate change in the proportion known to be the most. According to the OECD's 2050 Environmental Outlook in Korea is the OECD country with the most severe water stress was released. Water shortages in 2020, Korea has been known to enter the country. The OECD Green Growth policy of the keyword in the water to be present Water Footprint is produced from raw materials procurement, disposal and recycling of the product's life cycle to calculate the water usage of water resources is a technique to quantify the load. Water footprint calculations are used in the per-unit water consumption. In this study, to measure the carbon dioxide emissions and water usage more accurately measure who try and look for ways to manage
        5,500원
        166.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study is to find the substantial shortcomings embedded in the government policies and practical administrative processes associated with the Korean Transportation Database (KTDB) and to propose preliminary approaches to overcome. METHODS: Administrative and socioeconomic issues on inefficiency in public and private investment and redemption was found from the literature review. Through the interview of sets of experts and practitioners, a set of faultiness embodied in the administrative procedure utilizing and managing KTDB was found and analyzed. RESULTS: This study found the erroneous administrative elements categorized into four groups: faulty socioeconomic data supporting local governors’s optimistic will yielded overestimation of future traffic demand; faulty data incidentally introduced in KTDB burdened traffic demand analysis; unavoidable misuse of KTDB worsened the unstability of KTDB; and apathy to manage the KTDB data deviated systematic management. The proposed includes the alteration of the administrative and technical systems to overcome those shortcomings. CONCLUSIONS : Erroneous administrative elements associated with KTDB should be concerned prior to indicating subsequential faultiness in demand analysis.
        4,600원
        167.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The indoor air quality in public facilities has been well maintained as consciousness of facility owners is improved.However, the risk of PM2.5 and heavy metals in particulate matters have not been highlighted until now. So weinvestigated the particulate matters on major public transportation facilities such as subway, port and bus terminals.And we tried to figure out the characteristics of each facility groups by comparing the mass and metal concentrationbetween PM2.5 and PM10. As a results, the correlation between concentration of indoor particulate matters andthat of outdoor particulate matters shows higher strength in the case of bus terminals and port platforms thansubway platforms. However the total concentration of particulate matters and heavy metals were much higher insubway platforms than that of terminals and port platforms.
        4,000원
        168.
        2014.04 구독 인증기관 무료, 개인회원 유료
        The research team is developing design and construction technologies for 10Mw steel and 3Mw composite wind towers. Regulations related to land transport of wind towers significantly affect the constructability and economical efficiency of wind tower construction projects. Therefore, it is important to develop guidelines for wind tower construction which consider the regulations. This study investigates regulations and practices of land transport of wind towers as a basic study for the construction guidelines of wind towers.
        3,000원
        169.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Lately, a traffic information market has been developed with a rapid speed owing to information and communications. In this situation, a study on the use intention and the satisfaction of mobile transportation information applications of users will be diverse implications and a strategic foundation to local governments and transportation information related enterprises that should provide satisfactory info as public goods to much more users. METHODS : Going along with the flow, this study establishes features of the mobile transportation information applications aiming to the users and analyzes empirical causality for effects of the use intension and the satisfaction. Through this study's analysis, targeting users having experienced transportation information applications among smart phone users, a survey was conducted and characteristics of the transportation information applications were lighted and the effects of the use intention and the satisfaction were analyzed using a technology acceptance model. RESULTS : The analysis result was that Accuracy, Riskiness, Ubiquity and Interactivity as all attributes of transportation information applications have a significant effect on Perceived usefulness and Perceived Ease of Use respectively. The Perceived usefulness and Perceived Ease of Use have affected significantly users' satisfaction respectively, so consequentially this shows effect relationship leading to reuse intention. CONCLUSIONS : The Perceived usefulness and Perceived Ease of Use all for the transportation information applications were shown to influence significantly on the satisfaction. With this kind of result, if users obtain positive outcomes such as travel time reduction or effective roles on their tasks through the transportation information applications, they feel the satisfaction for using and eventually these affect positively to the reuse intention of those transportation information applications.
        4,000원
        170.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This research is a study on the changes in the road network of the surrounding area is installed according to the Kiss & Ride Zone. METHODS : Estimating the transportation mode of students by using the Metropolitan household Surveys(2006) and estimating the O/D by Kiss & Ride ratio with the estimated data, then being applied to a method of reducing the number of lanes for certain sections of the road which would be installed with Kiss & Ride Zone. RESULTS : The reason why it is different for delay resolving time and the affected roads as the Kiss & Ride percentage change, was the impact of the Kiss & Ride Zone's installation position. CONCLUSIONS : The purpose of the study was to analyze the impact of the road network in accordance with the installation of Kiss & Ride Zone by using speed and queue delay resolving time, and it is a need to develop a quantitative evaluation technique which was using various indicators in impact analysis according to the installation of the traffic safety facilities in the future.
        4,300원
        171.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Lots of criticism such as over/duplication investment, inconsistency of the policies among local governments and national plans etc. has been aroused due to the policy of supply-driven construction for transportation facilities. Recently, according to the environmental-friendly transportation policy, the investment of railroad has been expanded gradually, however the duplication with existing road facility makes it difficult to construct railroad. Thus it is necessary to evaluate the interrelationship between new project and existing facilities in the planning stage. However the method and the criteria for analyzing the duplication and over-investment of projects are not established in the manual, thus the feasibility of these projects are carried out from the economic point of view. METHODS: First, It reviewed about interrelationship criteria(domestic, overseas) and proposed implications and this study directions. Next, It developed the methods of evaluating independency, competitiveness and complementarity. RESULTS : In this study, the methods of evaluating independency, competitiveness and complementarity etc. are suggested to analyze the interrelationship between transportation facilities. The case study was carried out to examine the applicability of the methods. CONCLUSIONS: The methods raise rationality of decision-making compared to existing one. In the future, these methods are introduced into the manual of pre-feasibility study and feasibility study, more efficient decision-making and investment are expected.
        4,000원
        172.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유류를 포함한 위험 유해물질(Hazardous and Noxious Substances : HNS, 이하 HNS)의 물동량이 증가하는 추세에 있음에도 불구하고 우리나라에서는 HNS 해상운송 중에 일어난 사고의 분석과 위험에 관한 연구가 미진하다. HNS는 형태와 종류가 다양하고, 사고발생 시 피해가 심각하게 나타나기 때문에 사고에 대한 위험도 분석과 저감방안 모색이 필요하다. 본 연구는 ETA를 통해 국내에서 발생하고 있는 HNS 해상운송사고의 전개과정을 분석하여 사고유형과 특징을 고찰하고, 시나리오별 확률과 인명피해를 산출하여 F-N curve로 표현함으로써 위험도를 평가한다. 또한 Risk Matrix를 이용하여 고위험군 시나리오를 선정하여 국내에 적용 가능한 현실적인 사고 저감방안을 모색한다. 연구의 결과는 충돌사고의 발생확률이 가장 높은 반면 인명위험도는 발생확률이 낮은 질식, 침몰, 폭발의 사고유형이 높은 것으로 나타났다. 이러한 인명피해를 줄이기 위해서는 기본적으로 선내에서 안전수칙 및 작업절차를 준수하는 것으로도 효과를 얻을 수 있다.
        4,000원
        173.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        More and more medium and small enterprises do business across the world according to generalization of online shopping mall such as eBay and Amazon. But high export and import transportation cost make weak the price competitive power of medium and small enterprises products. Then this paper deals with the development of new business model which can reduce the transportation cost for global logistics through efficiently overcoming the constraints as length, size, and weight of product. We explain this model with application for company which export the automobile parts. We can expect the transportation cost reduction by 50%.
        4,000원
        174.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the location science, environmental effect becomes a new main consideration for site selection. For the unwanted facility location selection, decision makers should consider the cost of resolving the environmental conflict. We introduced the negative influence cost for the facility which was inversely proportional to distance between the facility and residents. An unwanted facility location problem was suggested to minimize the sum of the negative influence cost and the transportation cost. The objective cost function was analyzed as nonlinear type and was neither convex nor concave. Three GRASP (Greedy Randomized adaptive Search Procedure) methods as like Random_GRASP, Epsilon_GRASP and GRID_GRASP were developed to solve the unwanted facility location problem. The Newton's method for nonlinear optimization problem was used for local search in GRASP. Experimental results showed that quality of solution of the GRID_GRASP was better than those of Random_GRASP and Epsilon_GRASP. The calculation time of Random_GRASP and Epsilon_GRASP were faster than that of Grid_GRASP.
        4,000원
        175.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Logistics cost of domestic company has been improved continuously and annually, it is still higher than other main comparative countries. So, in this study, as optimizing the logistic network of distribution, it was trying to find methods decreasing logistics cost and storage cost, which occupies 86% of logistics cost of companies. through the efficiency of transportation and delivery routing, it could be also possible to decrease the logistics cost. And, it is also checked to find the logistics cost could be decreased by 10% by optimizing the routes of transportation and delivery, improving the transportation mode, etc.
        4,000원
        176.
        2012.11 구독 인증기관 무료, 개인회원 유료
        유류를 포함한 HNS의 물동량이 증가 추세에 있음에도 불구하고, 우리나라에서는 HNS 해상운송 중에 발생한 사고의 분석과 위험에 관한 연구가 미진하다. HNS는 형태와 종류가 다양하고 사고발생시 피해가 심각하게 나타난다. 액체화물운반선(유조선, 케미컬탱커선, 액화가스탱커선 등)의 사고에 대한 원인을 분석하고 위험성에 대한 연구가 필요하다.
        3,000원
        178.
        2012.10 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper is to present Smart Virtual TRS(Trunked Radio System) service that gives the TRS function in mobile network with smart phone application and server. TRS is essential equipment of logistics vehicle so, most of trunk drivers uses TRS frequently. Developed service is based on smartphone without TRS equipment. Therefore, Smart virtual TRS included in TMS(Transportation Management System) has some effects for logistics company. i) Smart Virtual TRS gives better communication environment between office and drivers. ii) Smartphone App gives flexibility to TMS functions. iii) Smart Virtual TRS gives cost reduction effect.
        4,000원
        180.
        2012.04 구독 인증기관 무료, 개인회원 유료
        Although all costs concerned in transportation be separated by region and each terms and conditions of Incoterms that state cleary them who have to pay the charges. But, almost lcl exporters donot want to pay their charges the carriers at loading port eventhough they make the contracts with the importer as FOB and CFR of Incoterms. And the carrier have been do not bill the FOB charges to the shipper. Now, there are no more Incoterms in LCL transportation. So, the importer have been payed loading port charges twice, first, the contract with the shipper, secondly, through the destination charge. These problems make decreasing of trading volume and increasing of logistics costs. We suggest every traders and carriers separate the costs as per the price terms and conditions of incoterms and bill / receive the costs separated the trader who have to pay the charges as per their price terms. It will bring mutual success in the world and increasing trade.
        4,000원