• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5622-5632
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• 2011

This paper presents the simulation design and analysis of Integrated Logistics System(ILS) which is operated by using the AGV(Automated Guided Vehicle). To maximize the operation performances of ILS with AGV, many parameters should be considered such as the number, velocity, and dispatching rule of AGV, part types, scheduling, and buffer sizes. We established the design of experiment in a way of Orthogonal Array in order to consider (1)maximizing the throughput; (2)maximizing the vehicle utilization; (3)minimizing the congestion; and (4)maximizing the Automated Storage and Retrieval System(AS/RS) utilization among various critical factors. Furthermore, we performed the optimization by using the simulation-based analysis and Evolution Strategy(ES). As a result, Orthogonal Array which is conducted far fewer than ES significantly saved not only the time but the same outcome when compared after validation test on the result from the two methods. Therefore, this approach ensures the confidence and provides better process for quick analysis by specifying exact experiment outcome even though it provides small number of experiment.

• 대한공업교육학회지
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• v.33 no.1
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• pp.134-148
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• 2008

In this study, a survey was conducted to determine the understanding by teachers at KIPO-funded high schools of the specialized training of invention patent personnel. The subjects were 4 high schools and 126 copies of questionnaires were collected for analysis. The results of this study are as follows. First, teachers understand that it is particularly important to provide a specialized training for students so that they can more effectively adapt to the changes in their lives. They also consider basic job skills training, moral education and job readiness training as equally important. Second, they recognize the necessity for a specialized training of invention patent personnel. Third, they think that redundant teachers arising from the reform of the curriculum for specialized training should be provided with minor training. Fourth, they think that the reform of the curriculum for specialized training should consider the following aspects: the development of a curriculum for invention patent-specialized high schools, the strengthening of administrative financial supports, the creation of a consensus among those involved for the success of the specialized training, the development of textbooks and materials, and the consideration of the future prospects and current conditions of the invention patent industry. Fifth, they think that the successful operation of specialized high schools requires the consideration of the following factors: users' understanding, conformance, selection & concentration and uniqueness.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.174-180
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• 2020

With the removal of underwater obstacles in the Busan New Port, the water depth of the pier has been secured up to 17m, and the port authority is constantly responding to the trend of container vessels becoming larger. Also, in 2020, 24,000TEU class container ships are entering to the port, and it is planned to secure the depth in the port to 23 m later in line with this trend. Mega container ships must check in advance the factors to be considered depending on the situation at the time, and for this, it is judged that information sharing among stakeholders is necessary. In this paper, to understand the effect of the corresponding route because of the mega container ships, a transit safety evaluation was conducted based on statistical data on ship entry and departure and maneuver characteristics of corresponding ships. The result showed that the transit of the mega container ships has increased up to 8.4% comparing to the risk of 4,000TEU class container ships. Additionally, safety measures such as minimum safety depth and tug operation plans were presented by gathering opinions on operational characteristics from the perspective of pilotage for safe transit in the Busan New Port area. Through this, it is considered that it will be possible to contribute to the prevention of accidents when entering and leaving the Busan New Port.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.680-687
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• 2016

Although advanced weapon system weapons with high-performance and various functions have been developed, weapon defects can be fatal in the weapons industry. Therefore, the army requires quality improvement to reduce the number of defects which occur during both the development and operation of the weapon system. Recently, many manufacturers, including weapons manufacturers, have conducted analyses using defect related big-data in order to improve the quality. However, there have been few data analyses, because it is difficult to obtain the data required for the analysis of the development phase. Therefore, this study summarizes the pattern of the weapon system, military organization, and defect types using the actual data of the Post-Logistics Support (PLS) phase. The PLS data, which is referred to as the data collected after force integration, includes information on requests for maintenance. Through this information, this study selects key variables and analyzes the selected variables. The analysis results show the critical factors to be considered during the development phase. Finally, this study proposes a framework for advanced PLS systems using the PLS data. The proposed framework enables the development time of weapon systems to be further shortened and their quality to be improved.

• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.8-14
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• 2004

To investigate the optimal operation factors in appling Soil Flushing Process, which use EDTA and boric acid composite as a flushing reagent, to the Cd(cadmium) and Cr(chromium) contaminated sites, Cd and Cr emediation rate was investigated at various experimental conditions; as EDTA concentration was increased from 0.001M to 0.1M, Cd remediation rate was increased from $73.2\%\;to\;98.5\%$; as boric acid concentration was increased from 0.001M to 0.1M, Cr remediation rate was increased from $59.2\%\;to\;99.0\%$. In the experiments using 0.005M of EDTA and 0.005M of boric acid composite as a flushing reagent at different pH regimes, Cd remediation rate was decreased from $92.4\%\;to;80.9\%$ as the pH was increased from 3 to 7. But Cr remediation rate was more effective ($70.4\%$) at pH 5 compared to the other pHs. Furthermore, at pH 5, Cd and Cr remediation rate was investigated at different molecular ratio of [EDTA]/[Boric aicd]; the optimized [EDTA]/[Boric acid] ratio was 0.01M/0.1M for Cd contaminated site and, as the concentration of boric acid was increased over 0.1M, Cr remediation rate was also increased. So the similar results were shown in the experiments using real contaminated soils which were sampled from a mining and a industrial area.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.445-450
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• 2011

Purpose: The objective of this study is to analyze the epidemiological characteristics of pediatric burn patients and to determine the targets for a pediatric burn prevention program. Methods: A retrospective review of all medical records of acute pediatric burn patients (age < 15 years old) admitted to our hospital between January 2005 and December 2009 was performed. Results: 1472 males and 1323 females were investigated, with a male to female ratio of 1.11 : 1. The greatest number of burn patients were those with an age of 1~2 years (1,463, 52.3%). Scalding burn was the most common cause of injury, which accounted for 2183 (78.1%) patients, followed by contact burns (10.5%), flame burn (4.9%), steam burn (3.6%). Especially steam burn was the second cause of injury in the age under 1 year, while flame burn was the second cause of injury in the age over 7 years. During recent 5 years, incidence of flame burn, steam burn, electrical burn gradually decreased. Variation of seasonal incidence is minimal and most of the patients (2,716 cases, 97.2%) had burns less than 20% TBSA (Total body surface area). The median hospital stay was 18.79 days, and the rate of operation was 28.6% with a high rate in electrical burn (76.2%), flame burn (50.0%), steam burn (46.1%). 6 patients died in this series, which yielded a mortality rate of 0.2%. Conclusion: Prevention efforts should reflect recent study results. Focused prevention program and campaign to make people aware of risk factors and their avoidance is required to reduce the number of burn accidents in children.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.855-860
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• 1998

Background: Adequate exposure of the mitral valve is a prerequisite for mitral procedures including the repair. An extended transseptal approach in mitral valvular operations is known to have certain technical advantages in recent years because of the anatomic posterior location of the mitral valve, especially in reoperations and in the presence of the small atrium in spite of the possibility of arrhythmia due to injury of sinus nodal artery. Material and Method: We compared the preoperative status, operative, and postoperative factors among patients in two study groups, transseptal only (Group I, n=10) and extended transseptal approach(Group II, n=25). Result: There were no differences in age, sex, NYHA functional class, left atrial size, and left ventricular function. The incidence of the redo-operation was high and early postoperative arrhythmia, which was improved later, appeared in 3 patients in Group II, but not in Group I. Conclusion: We believe that atrial septal incision could be extended up to the atrial roof whenever exposure of the mitral valve during a transseptal approach is inadequate because the late results were similar.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.17-27
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• 2003

In general, an airport access system has influenced on airport terminal operation. The congestion and delay in service facilities at an airport are definitely depended on the patterns of passenger arrival behavior and time spent in a terminal. Therefore, it is necessary to analyze the passenger arrival behavior at an airport to improve the operations at passenger terminal. Passenger arrival patterns to an airport are mainly depended on factors such as the length of access time. reliability of access time. and provision of transport modes, etc. The focus of this paper is to estimate the relationship between the length of access time and passenger's total time spent to board aeroplane. For this, passenger surveys were conducted at the Gimpo International Airport for a large airport and Sacheon Airport for a small size airport. The mathematical relationship between arrival time at an airport prior to the scheduled time of departure(STD) and access time spent was then estimated. It is considered that the results of this study can be used to reduce congestion and delays, thereby to improve the efficiency of the passenger services at the airports.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.67-78
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• 2012

The current traffic regulations in Korea stipulate that traffic should keep to the right according to the Road Traffic Act; thus, customarily, the 'seat-on-the-left' system has been maintained. However, an increased number of 'seat-on-the-right' vehicles are being imported via a variety of routes from foreign countries, especially from Japan. According to the data from July 2004, 1,343 cargo vehicles and 593 passenger vehicles (for diplomats, etc.) were currently being driven on domestic road. As these 'seat-on-the-right' vehicles are not compatible with the domestic transportation system of driving on the right side of the road, there is a high risk of accidents. Experiments show that such system-driver mismatch causes longer operation time for directional signals, higher error frequency in yielding due to additional mental adjustments for 'seat-on-the-right' vehicle drivers. These are, therefore, influential factors which can lead to possible accidents. Furthermore, when the experiments test the visual range during overtaking maneuvers, the visual range of the drivers in the 'seat-on-the-left' vehicle was 2.95 meters as opposed to 1.7 meters for the drivers in the 'seat-on-the-right' vehicle. (In the experiment, the drivers were instructed to look at the paper cup 10 meters away from the back of drivers' seat.) The results demonstrate that it is necessary to have additional safety measures be implemented for the 'seat-on-the-right' vehicles.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.210-219
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• 2017

Electric vehicles, which are attracting attention as eco-friendly vehicles, have been increasing in number since 2011 in Korea. The purpose of this study is to analyze the efficient operation of existing charging stations and factors to consider when installing additional charging stations based on the case of Jeju Island where the electric vehicle penetration rate is high and the charging infrastructure is relatively well established. The characteristics of using electric car charging stations by region, type of facility, and time of day are analyzed. As a result of analyzing the frequency of using the charger installed in Jeju Island, the utilization of both the fast charger and the slow charger is found to be concentrated in a specific area. The usage rate of charger installed in a business facility and a public parking lot is high in both fast charger and slow charger. However, according to the usage rate by time of day, the fast charger has a high utilization rate throughout the afternoon, while the use of a slow charger is concentrated in the morning. In order to enable users to utilize the electric vehicle charging station efficiently, it is necessary to provide a publicity guide for the charging station having a low utilization rate, a notice for using the charger, and a notification of completion of charging. Considering the charging demand, the area where the charger is not yet installed should be considered as the area to install the charger, and in addition, the additional installation should be considered in the area and the facility where the amount of charge is large. Service improvement is expected to be possible by utilizing actual electric vehicle charging behavior analysis result.