• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.149-157
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• 2008

Rapid urbanization causes a variety of transportation problems, including parking. Then transportation engineers would get involved in trying to solve parking problem. Estimation of parking demand is essential for finding a solution to the parking problem. Estimation of parking demand generally uses the "parking basic unit"; however, the parking basic unit does not totally determine parking demand. This study analyzes the problems with using the parking basic unit with a field investigation and the establishment of a new parking demand calculation model. Parking basic units estimated from the mean parking basic unit method are higher than those resulting from a regression analysis. However, parking basic units resulting from these methods fail to satisfy parking demand in many buildings. Analysis results for a cumulative distribution of parking basic units are reasonable if they satisfy 88% of parking demand in buildings. However, parking basic units that satisfy 88% of parking demand in buildings is a problem in some areas with an oversupply of parking lots. Ultimately, this study establishes a parking demand calculation model.

• Journal of Distribution Science
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• v.13 no.1
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• pp.83-91
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• 2015

Purpose - Despite the structural irrationality of multi-level transportation and the oil price rise, the domestic freight transportation market continues to grow, mirroring the rise in e-commerce and resultant increase in courier services and freight volumes. Several studies on courier services have been conducted. However, few studies or statistics have been published regarding regular freight services although they have played a role in the freight service market. The present study identifies the characteristics of regular freight service users to seek competitiveness enhancement measures specific to regular freight services. Research design, data, and methodology - IPA is a comparative analysis of the relative importance of and satisfaction with each attribute simultaneously. This study used IPA because it facilitates the process of analyzing importance and performance, deriving implications and a visual understanding of results. To enhance the competitiveness of regular freight services, this study surveyed its current users regarding the importance of the regular freight service factors. A total of 200 copies of a questionnaire were circulated and 190 copies were returned. In addition to demographics, respondents answered questions about the importance of and satisfaction with services on a 5-point Likert scale. Excluding 3 inappropriate copies, 187 out of 190 copies were analyzed. PASW Statistics 18 was used for statistical analysis. A total of 20 question items were selected for the service factors presented in the questionnaire based on the 1st pilot survey and previous studies. Results - According to the IPA performed to compare the importance of and satisfaction with service factors, both importance and satisfaction are high in the 1st quadrant, which involves the economic advantage of using regular freight services, quick arrival at destinations, weight freight handling, and less time constraints on freight receipt/dispatch. This area requires continuous management. Satisfaction is higher than importance in the 2nd quadrant, which involves the adequacy of freight, cost savings over ordinary courier services, notification on freight arrival, and freight tracking information. This area requires intensive investment and management. Satisfaction is lower than importance in the 3rd quadrant, involving the credit card payment system, courier delivery service, distance to freight handling sites, easy access to freight handling sites, and prompt problem solving. This area requires further intensive management. Both importance and satisfaction are low in the 4th quadrant, involving the availability of collection service, storage space at freight handling sites, kindness of collection/delivery staff, kindness of outlet staff, and easy delivery checks. This area is a set of variables should be excluded from priority control targets. Conclusions - Based on the IPA, service factors that need priority controls because of high importance and low satisfaction include the credit card payment system, delivery service, distance to freight handling sites, easy access to freight handling sites, and prompt problem solving. The findings need to be applied to future marketing strategies for regular freight services and for developing competitiveness enhancement programs.

• Korean Management Science Review
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• v.25 no.2
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• pp.89-109
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• 2008

As the importance of logistics is increasing, Enterprises try to design the supply chain(SC) network to minimize the total costs considering inventory holding cost, transportation cost and apply the efficient strategies of supply chain based on SC network. Despite of this efforts, Calculating the logistics costs without reflecting the real components of logistics like the packaging cost, transportation related cost, storage cost, loading & unloading cost, and distribution costs, the companies has many limitation to calculate the logistics cost of real enterprise. For overcoming such problem, this paper is aimed at establishing SC strategies which can be an efficient alternative for a decision making on supply chain, based on existing reference and current logistics networks of 'L' company in Korea. Also, we analyze the interaction effects between strategies as well as install the optimal SC network reflecting concrete logistics components from the viewpoint of total logistics costs using the simulation and statistic methods. we expect that analysis results of this paper would be applied various industries and be utilized to the efficient tools for the decision making by planing and execution of the logistics budget from enterprises.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.57-69
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• 2005

The goal of this paper is to develop freeway Origin-Destination (OD) demand estimation model using real-time traffic data collected from Freeway Traffic Management System (FTMS). In existing research, the micro-simulation models had been used to get a link distribution proportion by time process. Because of hi-level problem between the traffic flow model and the optimal OD solution algorithm, it is difficult for the existing models to be loaded at FTMS. The formulation of methodology proposed in this paper includes traffic flow technique to be able to remove the bi-level problem and optimal solution algorithm using a genetic algorithm. The proposed methodology is evaluated by using the real-time data of SOHAEAN freeway, South Korea.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.63-72
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• 2004

In conducting traffic safety programs, it is very important to identify hazardous sites in appropriate manner. The rate qualify control method is generally used in identifying hazardous sites since it can interpret the sites in the statistic aspects. The rate qualify control method is based on the assumption that the occurrences of traffic crashes follow the Poisson's distribution in which the expected value of traffic crashes equals the variance of those. However, there is greater variability than expected statistically, we call this phenomenon over dispersion. This study analyzed the problem related to the rate quality control method under the over dispersed data, and established a methodology to solve the problem. As a result of test on the basis of the field data, the new approach produced more reasonable results than those of the Poisson based rate quality control method.

• Journal of Practical Engineering Education
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• v.16 no.1_spc
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• pp.59-64
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• 2024

As the aging population grows, the incidence of cancer is increasing. Skin cancer appears externally, but people often don't notice it or simply overlook it. As a result, if the early detection period is missed, the survival rate in the case of late stage cancer is only 7.5-11%. However, the disadvantage of diagnosing, serious skin cancer is that it requires a lot of time and money, such as a detailed examination and cell tests, rather than simple visual diagnosis. To overcome these challenges, we propose an Attention-based CNN model skin cancer classification system. If skin cancer can be detected early, it can be treated quickly, and the proposed system can greatly help the work of a specialist. To mitigate the problem of image data imbalance according to skin cancer type, this skin cancer classification model applies the Over Sampling, technique to data with a high distribution ratio, and adds a pre-learning model without an Attention layer. This model is then compared to the model without the Attention layer. We also plan to solve the data imbalance problem by strengthening data augmentation techniques for specific classes.

• Management & Information Systems Review
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• v.32 no.3
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• pp.107-125
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• 2013

This study deals with a strategic decision making in two level supply chain network design. This study presents more realistic mathematical model than the previous studies by considering simultaneous location of plants and distribution centers, determination of capacity level for both plants and distribution centers, and upper limit condition for numbers of locating plants and distribution centers. This paper tries to help the strategic decision making for two level supply chain network design. For this purpose, three different sized numerical examples are generated and optimal solutions are obtained by applying Excel Solver program. And sensitivity analysis is performed for the biggest sized example problem, which has 10 potential plants, 20 potential distribution centers, and 200 customer zones. After the plants being located are fixed, optimal minimum costs are obtained and compared for each of 7 different numbers of distribution centers to be located. As the number of distribution centers increases, changes in inbound transportation cost and outbound transportation cost can be derived. In case of considering cost as well as customer satisfaction level for two level supply chain network design, the analysis of this changes may help more sophisticated decision making.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.223-224
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• 2014

Along with container freights keep increasing globally, lots of containers used for inland distribution increase steadily too. In Korea, there are many modes to transfer container freights such as roadway, railroad, coastal shipment. The roadway transportation is the most common but it is considered as the most inefficient mode. This paper studies about reasons that affect to the inefficiency of roadway transport and finds solution to resolve the problem. First backhaul transportation is addressed and some suggested solutions are presented such as construction of inland inspection center or managing efficiently container management. Then mathematical model is used to show the quantitative evaluation of backhaul transport solution.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.2
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• pp.49-56
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• 2020

Magnesium alloy is a metal with high specific strength and light weight, and is attracting attention as a next generation metal for environmentally friendly automobiles and transportation equipment. However, magnesium alloys have a problem of degrading formability due to the basal texture developed during processing, and their application is limited. Although active researches on the control of textures have been conducted in order to minimize this problem, there is a lack of research on the formation of microstructures and textures according to elemental differences. In this study, AZ61 and AZ80 magnesium alloys were selected to investigate the effects of aluminum addition on the microstructure development of magnesium alloys. This research has proven that the increase of the rolling rate results in the decrease of the average grain size of the two alloys, the increase of the hardness, and the increase of the fraction of twins. As shown on this research below, the basal texture developed strongly as the rolling ratio increased. On the other hand, this research also has proven that the two alloys exhibited different texture strength and distribution tendencies, which could be due to the effects of aluminum addition on work hardening, grain size, and twin behavior.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.73-80
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• 2013

Because the damages of corrosion resulting from the chloride ion are very serious, many research studies have been performed to measure the penetration depth of the chloride ion. However, there is a problem with data selection obtained from collection during experiments. In this study, it appears that the collected data are not conformed to a normal distribution. The result of this study will play a very important role, as a first step for the development and construction of a forecasting system to help determine a reliable service lifetime of marine structures.