• Journal of Korean Society of Transportation
• /
• v.31 no.4
• /
• pp.32-46
• /
• 2013

Because of short length between interchanges, traffic congestion has been caused by a lot of short trip traffic in the urban section of interregional expressway. Also, in case of expressway with Bus Only Lane, bus causes dangerous situation by conflicting between vehicles and buses in order to access from Bus Only Lane to IC. Therefore, this study aims to propose Express Lane applied by Bus Only Lane as a new lane operation in order to efficiently operate and to analyze the effectiveness on constructing Express Lane to the Pangyo-Hannam section in Gyeongbu Expressway. The study analyzes effectiveness by scenario using the micro traffic simulation tool, VISSIM 5.4. For this, the indicators which evaluate construction effect of Express Lane, are used by average delay time, average speed and total travel time. The results of the study showed the best effectiveness when Express Lane installed one, and it represented an ideal traffic condition when long distance trip traffic of the whole traffic is 25% in the study section. Therefore, the construction of Express Lane using Bus Only Lane achieves positive effectiveness on safety and expense aspect as well as uncongested flow.

• Journal of the Korean Geographical Society
• /
• v.48 no.4
• /
• pp.509-532
• /
• 2013

Minimum Housing Standard is an instrument to cope with the problems of public health and community hygiene, deterioration of working class housing conditions appeared commonly in the process of capitalist industrialization and rapid rural-to-urban migration. This paper aims to examine the institutionalization of histories of minimum housing standard in the advanced countries, and analyze the spatio-temporal changes and characteristics of households failing to meet the New Minimum Housing Standard in Seoul Metropolitan since 1995. The analysis of this paper is based on the census data on population and housing. The results are as follows; Households failing to meet the New Minimum Housing Standard in Seoul are 501,000 households(1.368 million person, 14.4%). This means Seoul has overtaken the national average 11.8% for the first time and there are structurally marginal band of households who can not improve the housing conditions by themselves. In addition, the fact that the rate of Seoul households living in the marginal shelter including the basement and rooftop room is the highest in Korea means the housing quality issues of Seoul is serious. Spatial distribution of households failing to meet the standard is divided into the northeast area and the southwest area in Seoul. Main features of the households are female-headed families, middle and old-aged people, divorce families, lower educated people, under and graduate students, non-apartments, dweller in 15~20 year old houses.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.51-63
• /
• 2011

This study suggests that prior to construction of the 2nd Changwon tunnel and implementation of the demanded free of charge on Changwon tunnel, it is recommended to improve the traffic facilities and management of the traffic condition in order to create an efficient road that will keep traffic flow to a minimum and maintain the facilities proper working order. It has been generally accepted that the 2nd Changwon tunnel is necessary to construct and open as soon as possible. This is due to the service level of current traffic volume in the Changwon tunnel pay toll road which have been so congested that the fees have increased causing a public complaint to be filed, demanding a early free of charge be implemented for the Changwon tunnel. Furthermore, the objective and impartial analysis of the traffic situation based on a simulation of the alternative and traffic congestion fees has been provided to make the early free of charge on toll road as soon as possible. Finally, careful attention should be paid to seek to make the early free of charge on toll road in order to minimize the damages both specified and unspecified that may arise the prompt settlement of construction repayments and security of minimum management fees should be given priority over other alternatives.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.4
• /
• pp.337-346
• /
• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.4
• /
• pp.131-140
• /
• 2012

The shortest path search algorithm of navigation is generally based on Dijkstra algorithm and considers only the distance using the weight. Dijkstra algorithm based on the distance mainly ought to perform the 'number of nodes 1' and requires a lot of memory, for it is to start from the starting node and to decide the shortest path for all the nodes. Also, it searches only the same identical path in case of any bottleneck due to an accident nearby, since it is based only on the distance, and hence does not have a system that searches the detour road. In order to solve this problem, this paper considers only the travelling time per road (travelling speed * distance), without applying speed criteria (smoothness, slow speed, stagnation and accident control) or road class (express road, national road and provincial road). This provides an advantage of searching the detour, considering the reality that there are differences in time take for the car to travel on different roads with same distance, due to any accident, stagnation, or repair construction. The suggested algorithm proves that it can help us to reach the destination within the shortest time, making a detour from any congested road (outbreak) on providing an information on traveling time continuously(real-time) even though there is an accident in a particular road.

• Journal of Ginseng Research
• /
• v.32 no.4
• /
• pp.275-278
• /
• 2008

Ginseng stem fungus gnat, Phytosciara procera, is reported as a ginseng pest for the first time. It is new to science that a member of the family Sciaridae is a ginseng pest. In our observation, larvae of the gnat can penetrate the stem of ginseng, and then they make a shaft in shoot and root. Number of adults captured by yellow sticky traps were peaked in twice, from late July to early August and from late August to early September. In a ginseng field, 29.7% of ginseng damaged by Phytosciara procera is also infected by bacterial disease caused by Erwinia carotobora. However, there is a possibility on environmental-friendly control, as a result of decreasing effect of damage over 85% when remaining a part of berry on peduncle than tatally remove.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.4
• /
• pp.258-271
• /
• 2010

In order to figure out hydrodynamic and water quality changes after completion of dike construction of the Saemangeum, which behaves as a semi-enclosed estuarine lake, numerical simulations based on fine grid structure by using EFDC were intensively carried out. In this study some limitations of precedent study has been improved and gate operation were considered. Also 3 phases such as air-water-sediment interaction modeling was considered. It is clear that inner mixing of the Saemangeum is dominated by Mankyeong and Dongjin riverine discharges rather than the gate opening influence through the Lagrangian particle tracking simulations. Vertical DO structure after the dike completion shows steep gradient especially at Dongjin river estuary due to lessen of outer sea water exchange. Increasing SOD at stagnantly changed man-made reservoir might cause oxygen deficiency and accelerating degradation of water quality. According to TSI evaluation test representing eutrophication status, it shows high possibility of eutrophication along Mankyeong waterway in spite of dike completion, while the index is getting high after final closing along Dongjin waterway. Numerical tests with gate operations show significant differences in water quality. Thus it should be noted that proper gate operation plays a major role in preserving target water quality and management for inner development plan.

• Korean journal of communication and information
• /
• v.27
• /
• pp.213-245
• /
• 2004

As we know, broadcasting implies a unilateral transmission by one sender to several recipients of information generally produced by third parties. Contrary to that, telecommunications implies an exchange between participants. Participants exchange information they produce during an interaction. However, in the age of convergence between telecommunication and broadcasting, it becomes difficult to determine exactly the boundary between services classified under telecommunications and those classified under broadcasting services. This means that new regulatory regime should be introduced to meet the convergence between telecommunication and broadcasting. In this article, we try to overcome the existing framework for understanding and regulating convergent services. In order to develop more powerful and useful framework for dealing with new convergent services, we focus on the original characteristic of "cast services," which could give us very significant basis for further discussion. "Cast services," such as traditional broadcasting services, have the characteristics of both public goods (non-exclusivity and non-rivalry in consumption) and non-interactivity. Depending on the existence of these three characteristics, we are able to apply different regulatory regime to those convergent services.

• Journal of the Economic Geographical Society of Korea
• /
• v.22 no.4
• /
• pp.488-512
• /
• 2019

This study examines the 'Asia Decoupling' hypothesis, focusing on changes in trade patterns between regions and countries, based on the latest value added trade statistics. As an analytical tool, indicators that can directly measure the degree of distribution of actual value added were used. Main findings are: Firstly, creating potential at regional level which used to be the growth engine of East Asia until the mid-2000s declined sharply after the global financial crisis. Secondly, in the development pattern of the value added distribution network, no positive change has been detected in the give-out or gain capacity of emerging countries that can generate future growth in East Asia through GVC development. Lastly, China's value added contributing capacity, as different from the hub countries in other regions such as US and Germany, has declined significantly since the mid 2000s, while its capability to benefit greatly increased, and the gain potential of advanced group countries in competition with China is decreasing. We suggest the establishment of intra-regional economic cooperation mechanism including all countries in East Asia for expanding the value creating capacity in the region.

• Journal of the Korean Electrochemical Society
• /
• v.12 no.2
• /
• pp.155-161
• /
• 2009

Lithium secondary batteries have been widely used in the portable electric devices as power source. Recently it is expected that the realm of its applications expands to the markets such as energy storage medium of hybrid electric vehicle(HEV), electric vehicle(EV). Cathode active material is crucial in terms of performance, durability, capacity of lithium secondary batteries. It is urgent to develope the technology for mass production of cathode material to cope with the markets' demands in the near future. In this study, a calcination furnace running in real production line is modelled in 3D, and the thermal flow and gas flow after chemical reaction in the furnace is analyzed through numerical computations. Based on the results, it is shown that large volume of $CO_2$ gas is generated from chemical reaction. High concentration of $CO_2$ gas and it's stagnation is clearly found from the reactant containers in which the reaction occur to the bottom area of the furnace. It is also studied that 15% or more $CO_2$ mol fraction could affect to proper formation of $LiCoO_2$ through TGA-DSC analysis. The solutions to evacuate carbon dioxide from the furnace are suggested through the change of furnace design and operating condition as well.