• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.5
• /
• pp.85-97
• /
• 2009

Continuous increase of traffic demand has caused confirmed congestion, fuel consumption, emission, safety, etc. as serious social problems at the present time. The Smart Highway Project has been conducted by the supervision of Ministry of Land, Transport and Maritime Affaire to solve such problems since 2007. The Smart Highway Project includes LDWS (Lane Departure Warning System), a system to prevent broadside collisions and accidents, as a sub-technology of road-vehicle associating technologies. This system warns drivers when their vehicle deviates from the lane where they are traveling at high-speed on the highway. In this paper, the LDWS was evaluated using CBA to analyze the socio-economic consequences. Estimated benefits include reduction of accidents and convenience of drivers. In addition, the economics according to the distribution rate is various when it comes to Lane Departure Warning Technology, the economics of both cases - positive scenario and negative scenario, which was analyzed. As a result, the Benefit-Cost ratio(B/C) of negative scenario showed 0.97 in 2020 and 1.36 in 2030 while B/C ratio of the positive scenario showed 1.04 in 2020 and 1.59 in 2030, which indicated that the higher distribution rate is, the higher the economics generates. Therefore, it is judged that the introduction of Lane Departure Warning Technology will result in high economics.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.42 no.2
• /
• pp.41-51
• /
• 2014

A self-administered questionnaire survey and face-to-face interviews were conducted on 150 local residents belonging to seven villages, 160 visitors and 86 experts in order to analyze the attitudes of groups of local residents, visitors as well as experts toward the development plan of Sobaeksan Jarak-gil. Reliability analysis and one-way ANOVA were performed on the data collected by a questionnaire survey using IBM SPSS Statistics 20.0 after coding. The Duncan Test was conducted as a post-hoc test. Based on the analytical results, in economic terms, the expert group expected an increase in income, improvement in living standards and increase in expenditure for the maintenance of local infrastructure. In environmental terms, the visitor group was highly concerned about the disruption of the local natural environment and ecosystem, destruction of local properties and landscape, increase in water/soil/air pollution and increase in solid waste and noise. In social and cultural terms, the expert group had higher expectation for excavation of traditional cultural properties, instillation of local patriotism and pride, and the visitor group was highly concerned about a rise in crime, destruction of indigenous culture/increase in imitations, and induction of conflicts between residents. It is estimated that these results will be used as basic data for establishing the development plan of the mountainous ecological trail reflecting opinions of various groups.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.8B
• /
• pp.730-737
• /
• 2003

In this paper, we present an efficient authentication proxy for IEEE 802.1x systems based on the port-based access control mechanism. An IEEE 802.1x system consists of PC supplicants, a bridge with authentication client functions, and an authentication server. For the network security and user authentication purposes, a supplicant who wants to access Internet should be authorized to access the bridge port using the Extended Authentication Protocol (EAP) over LAN. The frame of EAP over LAN is then relayed to the authentication server by the bridge. After several transactions between the supplicant and the server via the bridge, the supplicant may be either authorized or not. Noting that the transactions between the relaying bridge and the server will be increased as the number of supplicants grows in public networks, we propose a scheme for reducing the transactions by employing an authentication proxy function at the bridge. The proxy is allowed to cache the supplicant's user ID and password during his first transaction with the server. For the next authentication procedure of the same supplicant, the proxy function of the bridge handles the authentication transactions using its cache on behalf of the authentication server. Since the main authentication server handles only the first authentication transaction of each supplicant, the processing load of the server can be reduced. Also, the authentication transaction delay experienced by a supplicant can be decreased compared with the conventional 802.1x system.

• Journal of the Korean Institute of Gas
• /
• v.14 no.4
• /
• pp.51-55
• /
• 2010

The global activities to reduce the $CO_2$ emission as a greenhouse gas have been various efforts. Under this circumstance, small and medium sized gas field containing $CO_2$ to develop as LNG is not economic feasibility. Particularly, for the separation of $CO_2$ in gas field, separation facilities should be installed to add. This is and increase in plant construction cost and separated $CO_2$ emission into the atmosphere is not the result of greenhouse gas reduction. When the uneconomic gas field apply the KOGAS DME process, the gas field containing $CO_2$ can be increase economic feasibility because of natural gas and $CO_2$ can be use to resource gas. The Tri-reformer produced syngas as H2 and CO in KOGAS DME process and the resource gases are natural gas, steam, oxygen and $CO_2$. The $CO_2$ is used as raw material gases from recover $CO_2$ in DME process. In this study, we investigated range of application of $CO_2$ in gas field.

• Korean Journal of Poultry Science
• /
• v.20 no.3
• /
• pp.141-149
• /
• 1993

In order to develop a poultry manure dryer, a pilot dryer was designed and drying experiments were conducted to investigate the drying characteristics of poultry manure. According to the results, the pilot dryer could be operated without any air pollution problems. When poultry manure was dried from 79.2%(w.b. basis) moisture content, the final moisture content ranged from 38.7% to 57.9% depending upon the drying conditions. The drying results showed that drying rate was 189.8~198.0 kg/h and moisture evaporation rate was 124.0~125.4kg-$H_2$O/L. For this drying, electricity requirement was 9.5~19.3 Wh/kg and fuel consumption rate was 6.9~9.3 kg-$H_2$O/L with 50.2~65.1% thermal efficiency.

• Journal of Korean Society of Transportation
• /
• v.31 no.1
• /
• pp.37-46
• /
• 2013

Lane closure in freeway work zone due to maintenance and repair of freeway facilities results in abrupt change of traffic flow. Sudden change of traffic flow results strong interactions among vehicles, and reduces capacity compared to the ordinary traffic condition. Such capacity reduction is likely to cause congestion, traffic queues, and economic loss cost. This study aims to determine the base capacity for a short-term freeway work zone that can be used to establish a work zone schedule in advance without any traffic impact. First, the research collected detector data and schedule data of road works on all freeways in Korea. Second, the research determined 23 study sites finding the capacity values of work zone after matching two kinds of data. All study sites had varying characteristics regarding traffic flow being adjacent to work zone during road works. The capacity values were reviewed in terms of lane closure configuration, the types of work, and design speed. Finally, research proposed capacity values for a short-term freeway work zone with the design speeds of 100 kph, 120 kph and 1,700 pcphpl, 1,750 pcphpl, respectively.

• International Area Studies Review
• /
• v.15 no.2
• /
• pp.247-273
• /
• 2011

This study analyzes the impacts on the M&A and greenfield of macroeconomic variables of home and host countries, after identifying current status and characteristics of the M&A and greenfield related to the entering way of Korean firms in China. Main empirical results are summarize as follows. First, as for foreign exchange variable, the decreased value of Korea won shows the negative correlations with both of the greenfield and M&A. Second, the real interest rate of Korea to measure the cost of capital is not significant statistically. Third, while the host country's stock market index, Shanghai Comprehensive Index, shows the expected negative correlations with the investment in the case of small & medium firm and light industry, it shows the positive correlations which is not consistent with general expectation in the case of large firm and heavy industry. Fourth, the openness of host country shows the positive correlations with both of the greenfield and M&A. Finally, in regard to the M&A, China's GDP to measure the market size of host country is not significant statistically while it shows the strong positive relationship with the greenfield investment.

• Journal of Navigation and Port Research
• /
• v.43 no.4
• /
• pp.256-263
• /
• 2019

The trade volume of Northeast Asian countries is increasing and with the advent of the 4th revolutionary era, minimizing the logistics costs of firm is becoming an important competitive factor. With respect to this, in 2006, the government introduced a certified Integrated logistics firm system to improve the competitiveness of local logistics firms and reduce the logistics costs of firms. They argued that the certified Integrated logistics firm system increased the reliability of logistics firms and increased the efficiency of the logistics industry. On the other side, they argue that the system puts a burden on firms and becomes a big business-oriented market consolidation. This study analyzed the efficiency of Warehousing firms using DEA model. The CCR, BBC efficiency and RTS (return to scale) of 15 Warehousing firms were evaluated. This study also suggested the Warehousing firms which can be benchmarked based on analyzed information.

• Journal of the Korean Regional Science Association
• /
• v.35 no.1
• /
• pp.3-18
• /
• 2019

Urban sprawl has been criticized due to its negative effects, including the encroachment of farmland and open spaces, the increase in traffic congestion and air pollution, the decline of central city, the decrease in social capital, and the unfairness of tax burdens on infrastructure and public services. This study measures urban sprawl in the capital region of South Korea where the characteristics of urban sprawl have been known to be different from those identified in the U.S. metropolitan areas. In particular, the study examines whether the capital region has experienced the decline of the central city with an expansion of low density residential development in suburban areas. Three measurements, the sprawl index with population density, the ratio of changes in urbanized areas to changes in population, and the population density gradient, were employed to measure urban sprawl, and GIS mapping and descriptive analysis were used to examine the central city decline and the characteristics of development patterns in suburban areas. The results show that the capital region of South Korea is moving to the American style sprawled development with the decline of the central city and an increase of single detached homes in suburban areas, implying that policy makers need to develop growth management strategies to prevent urban sprawl and its negative effects that many U.S. metropolitan areas have suffered from.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.2
• /
• pp.327-333
• /
• 2019

For sustainable lunar exploration, the most required resources should be procured on site because it takes tremendous cost to transfer the resources from the Earth to the Moon. The technologies required for use of lunar resources refers to In-Situ Resource Utilization (ISRU). As the ISRU technology cannot be verified in the Earth, a lunar surface environment simulator is necessary to be prepared in advance. The Moon has no atmosphere, and the average temperature of the lunar surface reaches to $107^{\circ}C$ during the daytime and $-153^{\circ}C$ at night. The lunar surface is also covered with very fine soils with sharp particles that are electrostatically charged by solar radiation and solar wind. In this research, generation of vacuum environment with lunar soil mass in a chamber and simulation of electrostatically charged soils are taken into consideration. It was successful to make a vacuum environment of a chamber including lunar soils without soil disturbance by controlling evacuation rate of a vacuum chamber. And an experiment procedure for simulating the charged lunar soil was suggested by theoretical consideration in charging phenomena on lunar dust.