• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1416-1425
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• 2008

Urban railway carries large numbers of passengers during the rush hour. According to the announcement of Ministry of Land Transport and Maritime Affairs(MLTM), 221% of the congestion rate is reported in the SeoulMetro No.2 outer circle line from sadang to bangbea between eight and nine o'clock in the morning. This study analyzes the cause of the client's dissatisfaction about SeoulMetro such as the train delay, and decides the preference rank of the alternatives for congestion alleviation and enhancement of the transport capacity using Analytic Hierarchy Process(AHP).

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.145-155
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• 2009

This paper compares the relative performances of area and cordon tolls as opposed to the first-best congestion tolls with respect to alleviation of traffic congestion and social welfare. The comparison is done in the monocentric city where all the jobs are located at the city center. The study shows that the size of charging zones is similar in the two second-bests, but that the optimal toll level is higher in area pricing than in cordon pricing. Area pricing schemes turn out to perform better than cordon pricing schemes as measured by average speeds and daily average travel time. Accordingly, the former is shown to increase the social welfare more than the latter. In the case of the cordon tolls, the residents at the charging zones are exempted from the tolls. In this way, cordon tolls invite people into the most congested areas over the optimal level while partially negating the whole spirit of the congestion tolls.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2046-2052
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• 2016

Ramp metering is one of the most efficient and widely used control methods for an intelligent transportation management system on a freeway. Its objective is to control and upgrade freeway traffic by regulating the number of vehicles entering the freeway entrance ramp, in such a way that not only the alleviation of the congestion but also the smoothing of the traffic flow around the desired density level can be achieved for the maintenance of the maximum mainline throughput. When the cycle of the signal detection is larger than that of the system process, the density tracking problem needs to be considered in the form of the discrete-time system. Therefore, a discrete-time sliding mode control method is proposed for the ramp metering problem in the presence of both input constraint in the on-ramp and exogenous disturbance in the off-ramp considering the random behavior of the driver. Simulations were performed using a validated second-order macroscopic traffic flow model in Matlab environment and the simulation results indicate that proposed control method can achieve better performance than previously well-known ALINEA strategy in the sense that mainstream flow throughput is maximized and congestion is alleviated even in the presence of input constraint and exogenous disturbance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.298-305
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• 2019

The demand for the revitalization of marine tourism in Busan North Port is increasing due to changes in functions such as an increase in harbor traffic volume and the expansion of marine leisure space in Busan. As a result, Busan City plans to set a phased alleviation target for prohibition of cruise ship operations, and to lift the prohibition of excursion ship operations in North Port following the cancellation of the prohibition of excursion ship operations in South Port in 2017. The purpose of this study is to evaluate the risk of excursion ship operations in Busan North Port by applying the marine traffic assessment index and to examine the possibility of excursion ship operations. For this purpose, port status, marine accidents, and traffic flow of Busan North Port were investigated. In addition, marine traffic assessment indexes, such as traffic congestion, risk based on an ES Model, and IWRAP MkII, a maritime risk assessment tool, were used to assess the risk and possibility of excursion ship operations in Busan North Port. This study can be used as basic data for analyzing the risk factors that may occur when excursion ships are operated in Busan North Port and to define how excursion ships should operate, with related safety measures.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.167-175
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.169-176
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• 2005

This paper introduces the dynamic control of acceleration lanes at freeway-ramp junctions. The feasibility of operation with flexible length of acceleration lane was tested with most possible traffic conditions. The operational qualify was also evaluated using average speed and total thru-put at both ramp section and freeway section. A CORSIM microscopic simulation model was used to evaluate the operation quality with a variety or volume conditions and three acceleration lanes, each representing different length categories. In addition, tollgate O-D data including travel times were obtained for two sections on the Gyeong-bu Freeway where an effective merging distance has been largely reduced. Its effect was analyzed and compared to the simulation results. Finally, the effects of acceleration lane are discussed and operational improvement at junctions is presented as research findings.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1969-1980
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• 2013

The Traffic congestion is caused by the increasing traffic demand. Thus, economic losses have been increasing every year. To solve these problems, car sharing and rental car systems that are equipped with IT technologies emerge. Car sharing has many advantages-the alleviation of the traffic congestion, the saving of maintenance cost for cars, the reduction of car possessiveness, the solution for the hassle of car ownership, for business and personal duty, and the improvement of connectivity between public transportations-. The goal of the car sharing is to achieve low-carbon and eco-friendly transportation. In this study, we review papers related to the car sharing system and the cost system of traffic systems. We estimate the optimal cost of the cloud traffic system that is one of the car sharing services. We suggest a methodology to estimate operational cost and use cost through the analysis of cost system between similar traffic means. The range of the maximum and minimum cost was determined through the comparison and analysis of similar traffic means. Expected demand and the cost that people are willing to pay were estimated through optimized value pricing. The minimum cost per hour that was compared to the cost of rental car was estimated at 5,333 won and the maximum cost per hour that was compared to taxi cost was estimated at 17,700 won. The cost for users was estimated at 6,930 won. The cost of 50% demands was estimated at 6,550won. Future studies should analyze service hours of users, weather, demand pattern and trend and consider them into the cost estimation.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1425-1434
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• 2011

This experiment was designed to evaluate the effects of the processing method of common vetch seed (CVS) (Vicia sativa) on laying performance, egg quality, metabolic parameters and liver histopatology during the peak production period in hens. Lohman layers, 46 wk of age in 6 replicate cages each containing 4 hens, were allocated randomly to one of four dietary treatments. Diets were control (C) diet containing no common vetch and experimental diets containing 25% raw common vetch (RCV), 25% soaked in water for 72 h with exchange of water every 24 h (SCV) and 25% soaked&boiled at $100^{\circ}C$ for 30 minute common vetch (SBCV). Inclusion of RCV into the diet deteriorated all laying performance variables. SCV did not alleviate the adverse effect of raw common vetch on feed intake, egg weight, feed conversion, final weight and weight change. SCV partially alleviated egg production (p<0.001). SBCV diminished the adverse effect on feed intake, egg weight, feed conversion, final weight and weight change compared to raw vicia sativa (p<0.001). No significant difference was detected between SBCV and the control group in terms of egg production, feed conversion, final weight and weight change. Regardless of the processing method, all the common vetch groups had lower shell strength compared to the control group. Haugh units did differ between all groups (p<0.001). Inclusion of RCV and SCV into the basal diet decreased triglyceride, cholesterol, total protein and serum glucose concentrations (p<0.001). Hovewer, inclusion of SBCV into the basal diet increased these parameters. Liver samples were stained with Hematoxylin and eosin (HE) and evaluated by light microscopy. A biopsy of native liver tissue was used as a control. No histopathologic finding was present in the control group. Raw V. sativa compared with the control caused lipid accumulations in hepatocytes, severe congestion of hepatic blood vessels, inflammation, increased numbers of Kupffer cells and sinusoidal dilatations. Whereas, the livers from groups given treated V. sativa showed only different degrees of sinusoidal dilatations. Findings from the present study point out the risk of increased hepatic damage due to use of raw Vicia sativa. Increasing treatment of V. sativa lead to a decrease of liver damages. Inclusion of raw and soaked vetch seeds in rations affected adversely all parameters examined in laying hens. But alleviation was observed when soaked and boiled vetch seeds (SBCV) were fed. The results of these experiments indicated that soaked&boiled Vicia sativa seeds may safely be used at a 25% level in rations of laying hens.

• Hwankyungkyoyuk
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• v.4 no.1
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• pp.89-211
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• 1993

The Korean government embarked upon ambitious economic development plans in the 1960's the goals of development policy at that time were the elimination of absolute poverty and the alleviation of unemployment. With scant natural resources, the government had to push for industrialization based upon borrowed foreign raw materials with surplus local labor. Preoccupation with the economic goals of industrialization and export expansion left little room for considering environmental protection. It is evident that Korea's exported industrialization strategy of the past three decades has been a success in terms of income, production, and other macroeconomic indicators, but it cannot be denied that a host of undesirable side-effects have been created. These include environmental problems. congestion in several large cities, poor wealth distribution, and regional disparities. The environmental problems were recognized even in the early stage of development, but preoccupation with the pending economic goals of industrialization and export expansion left little room for considering environment protection. The perceived and actual seriousness of the problems, however, has reached such a level that further negligence may imperil political stability and developmental problems facing the world arise from a world economic order characterized by ever expanding consumption and production, which exhausts and contaminates natural resources and creates and perpetuates gross inequalities between and within nations. It will be necessary to develop new culture and ethical values, transform economic structures, and reorient, our lifestyles. Changing lifestyles can not be promoted by government policy initiative alone but through self=generated educational efforts and mutual training by people themselves. The citizens group for environment (NGOs) should assume these educational and training responsibilities starting from grass-root level of people. It must be reawakened to the reality that the environmental preservation for better quality of life is based on the development of human relationships, creativity, spirituality, reverance for the natural world and celebration of life, and is not dependent upon increased consumption of non-basic material goods. To carry on such environment education social movements and NGOs should (1) provides educational methodologies, which focus on values clarification and moving beyond clarification and moving beyond blame to constructive action. (2) provide training for leaders of business and industry, government, union and others on consumption and production. (3) initiate and support the training and work of environmental counselor who encourage responsible consumption. (4) cooperative with media to initiate and strengthen educational programs on the social environmental programs on the social environmental impacts of consumption and production and to build awareness of consumer responsibility and potential. Economic and social development can be compatible with environment protection : both can be achieved simultaneously. Effective environmental management depends on the various factors : political will, institutional arrangements, appropriate legislation, and availability of the requistite financial and technological resources, which is possible with a strong public awareness of the importance of environmental preservation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.309-316
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• 2008

This study was carried out to examine the effects of vitamin E on chronic gastric ulcer induced by alcohol treatment in rats. Chronic gastric ulcer model was established by oral administration of 70% ethanol at one time and supply of 15% ethanol for additional 7 days. Male Sprague-Dawley rats, approximately 200 g, were fasted for 24 hours and orally gavaged with 1 mL of 70% ethanol for the induction of acute ulcer. A supply of 15% ethanol dissolved in distilled water for 7 days were followed to maintain chronic gastric ulcer. Acute ulcer group was sacrificed at 3 hours after oral administration of 1 mL of 70% ethanol. Chronic groups were divided into three groups according to vitamin E levels; low-vitamin E (LVE, 0 mg/mL oil/day), normalvitamin E (NVE, 1 mg/mL oil/day) and high-vitamin E (HVE, 10 mg/mL oil/day). These groups were fed vitamin E free diets which were made of vitamin E free vitamin mix followed AIN-93M pattern for 7 days. Histological findings of congestion, hemorrhage and necrosis in gastric tissue were shown severely in acute ulcer group and LVE group of chronic ulcer groups. The concentration of gastrin in serum was significantly higher in LVE group. The content of histamine in stomach was lower in acute ulcer group but there was no significant difference among the chronic groups regardless of vitamin E levels. Content of malondialdehyde (MDA) in gastric tissue was higher in HVE group and activities of antioxidant enzyme, glutathione peroxidase (GPx) and catalase, were lower in HVE group. Myeloperoxidase (MPO) activities as a marker of neutrophils infiltration was significantly higher in LVE group. These results suggested that vitamin E supplementation has positive effects on healing of alcohol-induced chronic gastric ulcer through alleviation of gastric tissue injuries and reduction of the MPO activity in gastric tissue and gastrin in serum.