• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1324-1332
• /
• 2008

The change of the transportation circumstance related to the deep environmental pollution, escalation of the energy price, increasing social cost of the congestion and traffic accident, improving a income level, advanced social structure etc, is rapidly proceeded. For the corresponding this transportation circumstance, the role of the railway is being increased and that is friendly with environment, efficient for the energy, observed the time schedule and the transportation device which is high speed and safe mass transportation. In addition, government's R&D investment is being increased according to deeping a strength of the international competitiveness through the technical innovation. So railway's R&D investment is being increased. Accordingly, This study suggest improving a fruit of the R&D related to railway R&D system for a efficient R&D investment.

• Journal of the Korean Professional Engineers Association
• /
• v.45 no.5
• /
• pp.26-35
• /
• 2012

Korea is now the 12th largest economy in the world, surpassing its annual trade in the amount of $1 trillion, and it has joined the socalled 20-50 Club, becoming one of the seven countries in the world with capita income of more than $20,000 with population of 50 million. However it ranked 24th of the Global competitiveness index evaluated by World Economic Forum based on the basic requirements including infrastructures, efficiency enhances, innovation and sophistication factors, etc. The extensive and efficient SOC infrastructures are critical for ensuring the global competitiveness of each country. Effective modes of SOC facilities including quality roads, railroads, ports, air transport, etc will be able to reduce the annual traffic congestion cost as well as macro economic logistics costs in Korea, thereby the global competitiveness can be strengthened in the global market.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.7
• /
• pp.311-316
• /
• 2002

It has been a basic model for the present electric power industry that more than two generators compete, and thereby the market clearing price and the generation schedules are determined through the bid process. In order for this paradigm to be applicable to real electric power systems and markets, it is necessary to reflect many physical and economic constraints related to frequency and transmission in the dispatching schedule. The paper presents an approach to deriving a Nash bargaining solution in a competitive electricity market where multiple generators are playing with the system operator who mitigates the transmission congestion to minimize the total transaction cost. In this study, we take the effect of the line flows and the role of system operator into the Game. Finally, a case study has been demonstrated to verify the proposed cooperative game.

• Journal of the Korea Society for Simulation
• /
• v.6 no.1
• /
• pp.97-108
• /
• 1997

For the purpose of decreasing economic loss from the traffic jam, a car route guidance system efficiently utilizing the existing roads has attracted a great deal of attention. In this paper, the search algorithm for optimal path and alternative paths, which is the main function of a car route guidance system, was presented using evolution program. Search efficiency was promoted by changing the population size of path individuals in each generation, applying the concept of age and lifetime to path individuals. Through simulation on the virtual road-traffic network consisting of 100 nodes with various turn constraints and traffic volumes, not only the optimal path with the minimal cost was obtained, avoiding turn constraints and traffic congestion, but also alternative paths with similar costs and acceptable difference was acquired, compared with optimal path.

• Information and Communications Magazine
• /
• v.10 no.8
• /
• pp.77-87
• /
• 1993

There has been increasing attention paid to the influence of fascimile type of technologies on transportation costs. This attention is noticeable in large business companies, as fascimile become widely available in Korea. The importance of the fascimile usage is that it might effectively substitute for transportation, thereby reducing transportation costs. This paper presents an analysis of cost saving resulting from fascimile usage for substitutable trips. Data were collected from business companies on various aspects of the fascimile usage patterns, with particular emphasis on usage behavior substitutable for trips. Although by no means comprehensive, the analysis revealed that significant benefits can be derived from the usage of fascimile for substitutable trips in business settings. The results of benefit estimation show that net benefits turn out to be 7,608 won and 5,055 won per one usage for large and small companies respectively. If traffic congestion were to be considered, total social benefits would be higher.

• Journal of Navigation and Port Research
• /
• v.29 no.9
• /
• pp.795-800
• /
• 2005

Nowadays, road transportation which has played a key role in the market of both passenger and freight transportation is facing with a serious problem, the traffic congestion causing a delay of transportation. Therefore, railroad transportation is considered as an attractive alternative mode of inland transportation due to its inherent merits in mass transportation such as relatively low cost compared with road transportations, less air pollution and noise than other mode ets. In this paper, therefore, we examine the current situation of railroad transportation markets including TKR(Trans- Korean Railway}, TSR(Trans-Siberian Railway} and prospects for the connection of TKR-TSR. And then we examine the structure of the container transportation market by railroad in Korea with a brief analysis of the traffic volume of TKR-TSR.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.12
• /
• pp.6123-6138
• /
• 2018

Named data networking (NDN) is a new network architecture designed for next generation Internet. Router-side content caching is one of the key features in NDN, which can reduce redundant transmission, accelerate content distribution and alleviate congestion. However, several security problems are introduced as well. One important security risk is cache privacy leakage. By measuring the content retrieve time, adversary can infer its neighbor users' hobby for privacy content. Focusing on this problem, we propose a cache privacy protection mechanism (named as CPPM-DAM) to identify legitimate user and adversary using Bloom filter. An optimization for storage cost is further provided to make this mechanism more practical. The simulation results of ndnSIM show that CPPM-DAM can effectively protect cache privacy.

• Structural Engineering and Mechanics
• /
• v.90 no.3
• /
• pp.301-311
• /
• 2024

Different methods have been proposed in the literature for splicing the reinforcing bars in the construction of concrete structures, which are alternatively used depending on design requirements. The most common approach is the lap splicing which is known as a cost-effective method although, its main disadvantages including congestion of bars at the lap zone and consequently, material wastage has motivated utilization of the other techniques such as mechanical splices (couplers). To better evaluate the performance of the couplers, 6 reinforced concrete (RC) beams whose difference is only the type and location of splices have been experimentally studied in this paper. Based on the results, the mechanical connection of the bars did not markedly affect the load-carrying capacity of the specimens. Moreover, it was observed that after applying the loads and failure of the specimens, none of the bars ruptured at the splice location and all couplers remained undamaged.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.6 no.2
• /
• pp.57-69
• /
• 2007

The most important problem in logistic activities may be to decrease the transportation efficiency due to the traffic congestion in urban areas. The traffic congestion reduces the average travel speed of freight vehicles, and then increases the travel time. These problems can lead the logistic system to be inefficient. As a result, it causes an increase of transportation costs. In addition, the increased cost is a main barrier for the transition to an advanced logistic system. This study focuses on the analysis of key factors choosing commercial freight vehicles using Logistic regression-analysis with RP (Revealed Preference) data to solve the increase of private freight cars and transportation costs. Additionally, this paper presents policies to promote good use of commercial freight vehicles based on the results of this study.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.2
• /
• pp.214-227
• /
• 2003

Developing an application, it is difficult to catch an exact requirement with the conventional text-based method. It has also problems in verification and analysis at each developing stage. Therefore, if an adjustment is required with an error and change of requirement, a bad effect happen in the whole system. In this case, it also affect adversely on the developing cost and period. Meanwhile, if an analysis or verification is performed, the possibility of an error frequency reduces. Thus, not only is it easier to correct the error but also add an new requirement. This thesis embody a TCP/IP congestion control algorithm with SDL which provides automatically graphic interface, verification and analysis to each developing stage. Using SDL gave a clear representation embodiment in each developing stage and easiness of adjustment due to changing requirements or correcting errors. In addition, the stages of protocol have been certified in a simulation by verification of MSC and the results showed a possibility of developing a better TCP/IP protocol.