• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.1-10
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• 2005

This paper proposes a novel fault-tolerant gait planning of a hexapod robot considering kinematic constraints. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. It is shown that the conventional fault-tolerant gait of a hexapod robot for forward walking on even terrain may be fallen into deadlock, depending on the configuration of the failed leg. For coping with such deadlock situation, a novel fault-tolerant gait planning is proposed. It can avoid deadlock by adjusting the position of the foot trajectory, and has the same leg sequence and stride length as those of the conventional fault-tolerant gait. To demonstrate the superiority of the proposed scheme, a case study is presented in which a hexapod robot, having walked over even terrain before a locked joint failure, could avoid deadlock and continue its walking by the proposed fault-tolerant gait planning.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.268-275
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• 2011

This paper proposes two optimal path planning methods of a mobile robot using uDEAS (univariate Dynamic Encoding Algorithm for Searches). Before start of autonomous traveling, a self-controlled mobile robot must generate an optimal global path as soon as possible. To this end, numerical optimization method is applied to real time path generation of a mobile robot with an obstacle avoidance scheme and the basic path generation method based on the concept of knot and node points between start and goal points. The first improvement in the present work is to generate diagonal paths using three node points in the basic path. The second innovation is to make a smooth path plotted with the blending polynomial using uDEAS. Effectiveness of the proposed schemes are validated for several environments through simulation.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.159-167
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• 2009

The vehicles play a significant role in modern people's life as economy grows. The development of car navigation system(CNS) provides various convenience because it shows the driver where they are and how to get to the destination from the point of source. However, the existing map-based CNS does not consider any environments such as traffic congestion. Given the same starting point and destination, the system always provides the same route and the required time. This paper proposes a path planning method with traffic prediction by applying historical driving information to the Fuzzy theory and Bayesian update. Fuzzy theory classifies the historical driving information into groups of leaving time and speed rate, and the traffic condition of each time zone is calculated by Bayesian update. An ellipse area including starting and destination points is restricted in order to reduce the calculation time. The accuracy and practicality of the proposed scheme are verified by several experiments and comparisons with real navigation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.31-37
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• 2016

Ranging is divided into a synchronous scheme and an asynchronous scheme according to the presence of global synchronization between nodes. In general, the asynchronous ranging is preferred over synchronous ranging because it does not require an expensive high-precision oscillator for the global synchronization. On the other hand, in a conventional asynchronous ranging scheme, the packets, which are generated by all nodes in a positioning system of a large-scale infrastructure and need to be sent for localization by reference nodes, are considerable, which cause an increase in network traffic as the number of nodes increases. The traffic congestion lowers the throughput of the network leading to a considerable loss of energy. To solve this problem, this paper proposes a ranging scheme, in which virtual transmission slots randomly and discretely selected by a plurality of nodes are used to reduce the overheads needed in synchronizing the nodes, and the ranging is performed asynchronously based on the virtual transmission slots, thereby decreasing the network traffic. In addition, a performance test proved that the proposed ranging scheme was stronger than the TWR and SDS-TWR on an error range, even though the intensity of traffic was very low.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.135-145
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• 2009

Generally, the phases of constructing information systems are consisted of systems planning and selection, system analysis, system design, and system implementation and operation. These systems require many efforts and costs for additional development of modification requirements due to a frequent changes of business environments and business processes. Especially, inconsistencies between system design and system implementation usually happen during development steps because of the difficulties of program developments due to difficulties of capturing exact user requirements and frequent changes of user requirements. This paper proposes a scheme of implementing meta-data based applications for enterprises in order to reduce inconsistencies between system design and system implementation and to overcome limits of the existing coding-based development methods of applications which must use until disuse if they are developed once. Also, this paper presents a framework of repository system to systematically manage and utilize meta-data. The core concept of the proposed scheme makes outputs generated in the phases of system analysis and design into meta-data and is to easily develop and customize application programs using meta-data repository. Also, to show the applicability of the proposed scheme, it is applied to implement ERP system of 'H' automotive part manufacturer. As a result, the proposed scheme can gain improvements such as easiness and productivity of program development, easiness of maintenance, reusability of program components, etc.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.24-41
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• 2013

This study aims to investigate the complex planning processes and design ideas of the Gwanghwamun Plaza which was opened in 2009. The opening of the plaza was significant as it was built in order to restore the symbolic meaning of axis in the historical Joseon Dynasty that was distorted during the Japanese Imperialism. The plaza itself attracts many citizens and tourists by providing the empty ground carrying historical ambiences around. In this paper, the story of the Gwanghwamun plaza will be summarized. Particularly, the background of promoting the project will be discussed and the whole planning process will be dealt with. The plaza was realized through several stages. First, the planning stage will be reviewed. The planning stage had been a quite long process since the initial idea was discussed. Since the early 90s, the political decision of making the plaza was made through the change of people's understanding toward public space. At this stage, the city government worked together with diverse citizens and professionals to share the vision and to realize the right decision in making the plaza. Second, the design stage will be elaborated in detail. This is the second design stage. The former was the idea competition and the latter was the turn-key base. The final design scheme emphasized the restoration of symbolic axis and the forgotten Yukjo Street. The scheme consists of four zones such as history restoration zone, prospect and history representation zone, culture zone, and the urban zone. Through the whole design process, the original idea remained as it was. The design concept was "a place of memory and prospect." It emphasizes the history representation, view corridor, cultural activities platform as well as the emptiness and flexibility of the basic premise of the plaza. Finally, the construction stage will be discussed. There were some additions and omissions in the construction process. The design chances in the construction stage will be reviewed in detail. After the opening of the plaza, there were some changes in the detail design. We will discuss how and why these modifications were made. In the end, the social and cultural implication of the plaza will be discussed. The storytelling of the Gwanghwamun Plaza will contribute to the clear understanding of planning and design process of pubic places. Based on this reflection, we are able to think about some suggestions of public projects for the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.7
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• pp.809-815
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• 2018

Distributed generations (DGs) using renewable energy resources in power systems have been widely integrated, and many of these DGs have intermittency. DGs can significantly affect the overall voltage profile of the system through the reactive power control for a voltage support. Therefore, in the planning stage of the optimal operation and dispatch of voltage regulation devices, DGs' hosting capacity with the reactive power control scheme should be considered. In this paper, we model the IEEE 34-bus test feeder, including all essential equipment. An optimization method is utilized to determine the optimal siting and operation of the voltage regulation devices in the presence of DGs with reactive power control scheme. Finally, we compare the optimal results of the each case to analyze the relationship among the hosting capacity of the DGs and voltage regulation devices operation.

• International Journal of Contents
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• v.13 no.2
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• pp.29-34
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• 2017

Cloud computing is becoming an effective and efficient way of computing resources and computing service integration. Through centralized management of resources and services, cloud computing delivers hosted services over the internet, such that access to shared hardware, software, applications, information, and all resources is elastically provided to the consumer on-demand. The main enabling technology for cloud computing is virtualization. Virtualization software creates a temporarily simulated or extended version of computing and network resources. The objectives of virtualization are as follows: first, to fully utilize the shared resources by applying partitioning and time-sharing; second, to centralize resource management; third, to enhance cloud data center agility and provide the required scalability and elasticity for on-demand capabilities; fourth, to improve testing and running software diagnostics on different operating platforms; and fifth, to improve the portability of applications and workload migration capabilities. One of the key features of cloud computing is elasticity. It enables users to create and remove virtual computing resources dynamically according to the changing demand, but it is not easy to make a decision regarding the right amount of resources. Indeed, proper provisioning of the resources to applications is an important issue in IaaS cloud computing. Most web applications encounter large and fluctuating task requests. In predictable situations, the resources can be provisioned in advance through capacity planning techniques. But in case of unplanned and spike requests, it would be desirable to automatically scale the resources, called auto-scaling, which adjusts the resources allocated to applications based on its need at any given time. This would free the user from the burden of deciding how many resources are necessary each time. In this work, we propose an analytical and efficient VM-level scaling scheme by modeling each VM in a data center as an M/M/1 processor sharing queue. Our proposed VM-level scaling scheme is validated via a numerical experiment.

• Journal of Broadcast Engineering
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• v.20 no.6
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• pp.848-861
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• 2015

In this paper, we introduce a new web-based PR video making service system. Many video editing tools have required tough editing skill or scenario planning stage for a just simple PR video making. Some users may prefer a simple and fast way than sophisticated and complex functionality. To solve this problem, it is important to provide easy user interface and intelligent classification and recommendation scheme. Therefore, we propose a new template classification and recommendation scheme using a topic modeling method. The proposed scheme has the big advantage of being able to handle the unstructured meta data as well as structured one.

• Science of Emotion and Sensibility
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• v.4 no.2
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• pp.57-62
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• 2001

In the car design process, Interior color scheme is one of the important factors that determined consumer's emotional evaluation with a car styling. The systematic research on the car interior color planning may be not achieved in spite of its importance because it is difficult to simulate color scheme before deciding final prototype. The various alternative of color scheme can be simulated and evaluated in early stage of car design process based on upgraded performance of computer hardware and advance41 co-work system. This study proposed a color coordinate support system for car interior color design to support designer based on emotional scale of color image. Color coordinate support system have four kinds of module, that is, the information acquisition module for gathering user's emotional data, the evaluation module for analyzing relation of color impressions and color attributes, the simulation module for supporting color coordinate design, and the evaluation support module for testing final color alternatives.