• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6799-6806
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• 2015

Electric energy consumption is always followed by the introduction of diversity scale-up and state-of-the-art equipments in logistic centers. In order to analyze the status and the characteristic of the electric energy consumption quantitatively, and also to evaluate the efficiency of the electric energy, this research aims to develop an estimation model of standard electric energy consumption for logistic centers. The proposed model applies the thermodynamics theory so as to effectively reflect the peculiarity that the temperature in the logistic center influences the electric energy consumption. And the model consists of the energy consumed by the refrigerator, which can be subdivided into the heat conducted through the wall, the heat convected by the open doors and the heat lost into the goods, and the electric consumption of the machinery equipments. The model also includes a variety of explanatory variables to support an operator of logistics centers in evaluating the efficiency of energy consumption and establishing improvement strategies for energy efficiency. Application of the model developed in this study is discussed with observed data on energy consumption of a logistics center.

• International Commerce and Information Review
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• v.15 no.2
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• pp.3-23
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• 2013

In 1997, 180 countries signed the Kyoto Protocol in Kyoto, Japan. The Kyoto Protocol came into force in February 2005. The agreement calls for industrialized nations to cut greenhouse gas emissions by 5 percent from 1990 levels by 2008 to 2012. One of those polices is a modal shift that change from road freight to sea, inland waterway and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior than the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and freight transport popularly until the middle of 20th century, however, by the sudden change of logistics environments, a shaving time efficiency being most important, railroad logistic lost its competitive power against the transportation by truck. From the research which sees consequently investigated a various policy, a system and a law about Chinese logistics industry and present condition of the Chinese goods enterprise and instance analysis of the large Chinese corporation that branch out to undeveloped markets led and a Chinese logistics industry and problem point escape hereafter the heightening of competitiveness plan which is rational under prsenting boil.

• The Journal of Society for e-Business Studies
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• v.21 no.4
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• pp.55-67
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• 2016

Global courier companies have been devoting to get more customers and profits with different service because of the worse profits from price competition. So, the effort of improving satisfaction of customers through improving courier service qualities is more important than any other time. However, the previous way to measure courier service has limitation that costs lots of time and money from off-line survey. This limitation could be overcome with less effort and costs if utilizing on-line social big data analysis and it is so helpful to improve competitiveness of courier companies. Therefore, I have collected comments from domestic and international courier companies from big data on social network service, analyzed the satisfaction of customers by R and verified the result by comparing with American Customer Satisfaction Index (ACSI) and Korea National Customer Index (NCSI) in this research. I found out the result depicts clear correlation between SNS analysis and customer satisfaction. This study can be the foundation to predict customer satisfaction easily by utilizing real time SNS information.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.8
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• pp.419-428
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• 2017

In this study, energy loss due to ventilation load in the dock system was analyzed through simulation. Also, flow generated in the dock system of the warehouse was measured using manufactured measuring devices. Numerical simulation was conducted by simulating the most common picking tasks by examining the actual working environment. Incompressible and unsteady turbulent flows were assumed, and the turbulence model was the k-e standard model. Proper grid was selected through grid dependency test. Measurement was conducted using Honeywell and Vaisala sensors, and flow and temperature inside the warehouse were measured and compared with simulation results to validate simulation. When comparing amount of loss occurring in two hours and amount of loss occurring in 15 minutes, docking time of the former was eight times longer but energy loss was 3.8 times lower. Ventilation load occurring during the initial period after opening docking system accounted for a large proportion of total ventilation load. Also, comparing the load when the dock was closed and the load when the truck was parked, ventilation load was significantly higher than load due to heat conduction from the wall. Therefore, in improving the docking system, it is effective to reduce the gap by improving compatibility of the docking system and truck, rather than wall material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8516-8524
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• 2015

Track irregularities can be evaluated not only directly by track inspection but also indirectly by measurement of carbody accelerations and many researches are being conducted. Carbody accelerations were measured on the Kyeongbu high speed railway and France high speed line to investigate the situation of the track maintenance at Korea high speed line by using indirect method. Digital signal processing for the measured acceleration data were conducted according to UIC518 code. Since the vehicle speed affects the car body acceleration, the lateral and vertical acceleration of the car body were classified according to the vehicle speed and the distribution characteristics of these acceleration were investigated and evaluated by UIC518 criteria. Finally, the running behavior of KTX on Korea high speed railway were compared with that on France. Distribution characteristics of these acceleration were evaluated and discussed in terms of the track maintenance in Korea high speed line.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.395-401
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• 2007

Recently, the government of Russia has been cooperating with developed countries such as Germany, which have an advanced railroad system. They have been establishing a strategy to activate the Siberia Trans Railway. Thus, it is possible that a part of cargo will be transported by TSR (Trans Siberia Railway) instead of shipping. If there is a railroad system, connecting the North and the South Korea via the Busan port, a new freight route linking to Europe will be reached. This paper aim to investigate the intention of shipping companies, shipper, forwarders, who are prospective customers and/or competitors of TSR. An analysis of the competitiveness between TSR system and the waterway transportation will be also mentioned.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.267-273
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• 2008

Many people transfer from the automobile to the subway because of increasing in oil price and improvement of mass transit system of Seoul Metropolitan City. But Seoul Metropolitan Subway have brought out passengers discomfort because it is more crowded over the appropriateness because of very high utilization though it is highly technically facilitated. This study deals with the development and simulation study of subway train simulator. We performed the validity simulation study for the simulator for the interval from Sindorim station to Samsung station in Seoul Subway Line 2. We analyzed the simulation results considering crowdedness after we defined the concept of crowdedness. Also we accomplished the analysis of simulation results after simulation under the assumption that the crowdedness is alleviated by controlling the passengers using RFID technology.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.177-181
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• 2017

Auxiliary power supply for railway vehicle is a equipment that focuses on the service of passengers in a vehicle. It supplies power to controllers used in heating and cooling devices, fluorescent lamps, batteries and many other electrical equipments. Most of the auxiliary power supply for railway vehicle are mainly used for the round trips and circulation routes within the metropolitan area and have a capacity of 170~200 kVA. In this study, we developed the auxiliary power supply capacity to 240kVA for 200km/h class. As such, the auxiliary power supply is an important device for securing the reliability and safety of the railway vehicle and improving the passenger convenience, so the performance verification of the performance must be ensured. In this paper, 240kVA auxiliary power supply is developed. Also, performance of the auxiliary power supply manufactured through the analysis of various characteristics related to the auxiliary power supply was confirmed while operating the actual line.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.778-784
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• 2017

In this paper, we propose wired and wireless distributed control systems designed to improve the freight logistics efficiency and verify wired distributed control systems. The verification condition required that 50 cargo vehicles be connected and operated to travel 21 km from Busan Sinhang station to Jinlye Station at an average speed of about 100km/h. The verification results show that the traction output and braking output of the control and controlled cars are dispersed by the wired distributed control system. The application is expected to more than double the efficiency of the logistics compared to the existing freight transportation system. However, in the case of the wired distributed control system, cable installation and maintenance are difficult, and it is impossible to change the combination of freight vehicles. Through the verification of the wired distributed control system, the applicability of distributed control systems to freight vehicles in Korea was confirmed and the system was further developed to produce a wireless distributed control system. In order to apply the wireless distributed control system, a propagation environment analysis for the ISM band was performed in the testbed and, as a result, it was confirmed that Wifi technology using the ISM band could be utilized. In order to use the WDP (Wireless Distributed Power) devices newly installed in the target vehicles, the transmission / reception control signals associated with the propulsion / braking / total control devices are defined. In the case of wireless distributed control systems, the convenience of their application and operation is guaranteed, but reliability and emergency safety measures should because of the dependence of the control of the vehicle on radio signals.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.265-274
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• 2017

For accurate demand forecasting of railway logistics, we estimated intercity freight mode choice models based on the binary logit model and using production-consumption data from the Korea Transport Database. We estimated two types of models and compared the results by major item of railway logistics, such as container, cement, and steel: 1) The aggregate freight mode choice models are based on the revealed preference (RP) data and 2) The disaggregate models are based on the stated preference (SP) data. With respect to the container, the travel time variable was found to be statistically significant; however, the travel cost variable was not statistically significant in the RP model, while the travel cost variable was statistically significant in the SP model. For cement and steel, the travel cost variables were statistically significant but the travel time variables were not statistically significant in either the RP or the SP models. These results are inconsistent with results from previous studies based on SP data, which showed that the travel time variables were significant. Consequently, it can be concluded that the travel time factor should be considered in container transport, but that this factor is negligible for cement and steel transport.