• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.76-90
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• 2022

The platooning refers to a form in which one or more following vehicles along the path of the leading vehicle(directly driven by the driver) drive in one platoon using V2V, V2I communication and vehicle-mounted sensor. Platooning has emerged in line with the increasing demand for cargo volume and advanced transportation logistics systems, and is expected to have effects such as increasing capacity, reducing labor costs, and reducing fuel consumption. However, compared to general passenger cars, research on autonomous driving of trucks and verification of their effects are insufficient. Therefore, in this study, meta-analysis was conducted on the theme of the effect of truck platooning, and the results of existing studies related to platooning effects were integrated into one reliable, generalized, and objective summary estimate. In conclusion, it was analyzed that the introduction of truck platooning would have an effect of 13.93% increase in capacity, 38.76% decrease in conflict, and 8.13% decrease in fuel consumption.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.72-81
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• 2013

Many articles have been published about a 2-degree of freedom model that includes the lateral and yaw motions for controller synthesis in intelligent transport system applications. In this paper, a 3-degree of freedom linear model that includes the roll motion is developed to design a robust steering controller for lane following maneuvers using ${\mu}$-synthesis. This linear perturbed system includes a set of parametric uncertainties in cornering stiffness and unmodelled dynamics in steering actuators. The state-space model with parametric uncertainties is represented in linear fractional transformation form. Design purpose can be obtained by properly choosing the frequency dependent weighting functions. The objective of this study is to keep the tracking error and steering input energy small in the presence of variations of the cornering stiffness coefficients. Furthermore, good ride quality has to be achieved against these uncertainties. Frequency-domain analyses and time-domain numerical simulations are carried out in order to evaluate these performance specifications of a given vehicle system. Finally, the simulation results indicate that the proposed robust controller achieves good performance over a wide range of uncertainty for the given maneuvers.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1730-1733
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• 2004

Device miniaturization and high integrated circuit design is of major interest for the development of electronic devices. Various studies have been conducted to develop new material and processing technique[1]. Negative Differential Resistance(NDR) is the defining behavior in several electronic components, including the Esaki diode and most notably, resonant tunneling diodes(RTD)[2]. We made a comparison of electrical properties between 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene and 4-[2,5-dimethoxy-4-(p henylethynyl)phenyl]ethynylphenylethanethioate, which have been well known as a conducting molecule having possible application to molecular level NDR devices. As a result, we measured current-voltage curves using Scanning Tunneling microscopy(STM), I-V curves also showed several current peaks between negative and positive bias region.

• Journal of Distribution Science
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• v.18 no.4
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• pp.39-50
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• 2020

Purpose: This paper aimed to study the current locations of post offices to analyze service coverage area for parcel delivery in the Eastern Economics Corridor (EEC), which must be considered in the last mile to extend delivery service for e-commerce growth. Thailand Post was the case study in this paper. Research design, data and methodology: To involve solving the delivery service area under the last mile condition, the authors proposed a network analysis to determine service radius by employing a Geographic Information System (GIS). Furthermore, this paper applied Dijkstra's algorithm as a network analysis tool from GIS for analyzing the last mile service coverage area in a new economics zone. At the same time, the authors suggested an approach as a solution to locate last mile delivery center in EEC. Results: The results of the study pointed out that Thailand Post should consider more last mile delivery centers in EEC to support its express service in urban areas as well as improve the efficiency of service coverage for parcel delivery and create more advantages against competitors. Conclusions: This paper proposes a network analysis to extend the last mile service for parcel delivery by following Dijkstra's algorithm from GIS and a solution approach to add more last mile delivery centers. The results of the research will contribute to boosting customer satisfaction for last mile delivery service and enabling easy accessibility to a service center in EEC.

• IE interfaces
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• v.18 no.4
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• pp.454-464
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• 2005

In Postal logistics, the efficient design and operation of transportation network is very important issue. But, it is hard to operate the postal transportation network flexibly according to the change of mail volume. In Korea post, a transportation plan is pre-determined and the transportation of mail is performed through the routes in the plan. When the routes cannot transport all mail, temporary vehicles are used. In the postal transportation, it is important to make a good transportation plan and to manage the plan efficiently. But the change of transportation plan is not a simple work because hundreds of vehicles and persons are related to the plan. So, a methodology to check the effect of the change of the transportation plan in advance is required. In this paper, we develop a simulation model to evaluate the performance of a postal transportation plan. We implement the simulation model and develop an information system including user interface for managing data and simulation results. We apply our simulation model and system to the real change of transportation plan.

• The Journal of Industrial Distribution & Business
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• v.3 no.2
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• pp.5-16
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• 2012

Purpose - Distribution channels cannot function without cooperation. While evidence suggests channel power plays a fundamental role in fostering successful manufacturer-dealer channel cooperation in Western countries distribution systems, little is known empirically as to how dealers' possession of non-mediated powers influence SME manufacturers' cooperation in Asian developing countries. Research design, data, methodology - Drawing upon the extant distribution channels literatures; this study conceptualizes a model and examines the effects of dealer's non-mediated powers on manufacturing SME firms, as well as the mediating influence of trust, relationship satisfaction and commitment. A survey of 400 manufacturing SMEs in Taiwan empirically supports the proposed hypothesis. Results - The model is acceptable in terms of overall goodness of fit. Acceptable model fit are indicated by χ²/(df): 2.35, GFI≧.90; RMSEA values≦ .08; IFI, TLI and CFI values≧.90. Our results indicate that, GFI (0.910), IFI (0.937), TLI (0.903), CFI (0.936), and RMSEA (0.079) and therefore, achieved the suggested thresholds. Conclusions - The results of this study have some managerial implications for managers in the dealer's firms. The overall implication from the findings is that managers can utilize expert, referent and traditional legitimate powers to attain channel cooperation with manufacturing SMEs in addition to garnering their trust, relationship satisfaction and commitment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.6169-6187
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• 2017

With the fast growth of mobile services, Mobile Cloud Computing(MCC) has gained a great deal of attention from researchers in the academic and industrial field. User authentication and privacy are significant issues in MCC environment. Recently, Tsai and Lo proposed a privacy-aware authentication scheme for distributed MCC services, which claimed to support mutual authentication and user anonymity. However, Irshad et.al. pointed out this scheme cannot achieve desired security goals and improved it. Unfortunately, this paper shall show that security features of Irshad et.al.'s scheme are achieved at the price of multiple time-consuming operations, such as three bilinear pairing operations, one map-to-point hash function operation, etc. Besides, it still suffers from two minor design flaws, including incapability of achieving three-factor security and no user revocation and re-registration. To address these issues, an enhanced and provably secure authentication scheme for distributed MCC services will be designed in this work. The proposed scheme can meet all desirable security requirements and is able to resist against various kinds of attacks. Moreover, compared with previously proposed schemes, the proposed scheme provides more security features while achieving lower computation and communication costs.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.331-341
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• 2011

This paper considers an inbound lot-sizing and outbound dispatching problem for a single product in a thirdparty logistics (3PL) distribution center. Demands are dynamic and finite over the discrete time horizon, and moreover, each demand has a delivery time window which is the time interval with the dates between the earliest and the latest delivery dates All the product amounts must be delivered to the customer in the time window. Ordered products are shipped by multiple vehicle types and the freight cost is proportional to the vehicle-types and the number of vehicles used. First, we formulate a mixed integer programming model. Since it is difficult to solve the model as the size of real problem being very large, we design a conventional genetic algorithm with a local search heuristic (HGA) and an improved genetic algorithm called adaptive genetic algorithm (AGA). AGA spontaneously adjusts crossover and mutation rate depending upon the status of current population. Finally, we conduct some computational experiments to evaluate the performance of AGA with HGA.

• Journal of Distribution Science
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• v.17 no.12
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• pp.43-54
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• 2019

Purpose: Marine transportation companies must improve service quality to secure competitive advantage and continuous relationships with customers. This study explores the value and necessity of service quality in the industry by empirically identifying the factor that would have the largest effect on the improvement of service quality, also examining whether such improvement may actually influence continuous relationships. Research design, data and methodology: Based on an online survey with those in the Korean marine transportation industry, this study conducted statistical analyses using structural equation modeling. Based on relevant previous studies, the current study constructed a total of 55 survey questions. Finally, 281 questionnaires were collected, but 68 were excluded owing to invalid responses. Results: Information service attribute had the largest effect on service quality, whereas communication did not demonstrate a significant influence. In addition, distribution and information services exerted a positive effect on service satisfaction through service quality, and finally influenced relationship continuity. Conclusions: The results shows that marine logistics service quality strategies which were centered on time or local factors, should be considered in terms of the development of innovative services. In particular the improvement of information service systems and strategies in changed business environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1373-1380
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• 2015

The rapid spread and various design of solar power plants, development, construction, maintenance technology and business coexist variety and price decline and the recent solar power plants built since the early 2010 despite the decline in the power generation unit main equipment Construction of power plants to stabilize the technology has been continuously promoted. Recently, built in the form of a solar power plant to the construction and leasing the roof and upper structure to replace the limited ground space is increasing. Factory roof, studies such as warehouse and logistics center leased space in the roof installed solar plant status and skills, conducted a study to review and analyze the economy.