• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.1
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• pp.72-78
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• 2006

Distributed generation (DG) systems go to intentional islanding operation to back up private emergency loads when the main grid is out of electric power. Conventional utility interactive inverters normally operated in current control mode in DG system must change their operation mode into voltage control mode to ensure stable voltage source to the emergency loads when intentional islanding operation occurs. During the transfer between current control mode and voltage control mode, serious transient problem may occur on the output terminal voltage of the utility interactive inverter. This paper proposes reasonal inverter topology and its control algorithm for seamless transfer of DG systems in intentional islanding operation. Filter design guide line and data for a LCL filter that is appropriate for the proposed control algorithm are also presented by the authors.

• Journal of Intelligence and Information Systems
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• v.12 no.3
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• pp.1-13
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• 2006

Ubiquitous computing is a study area explained in a myriad of contexts and technological terms. Payment, however, refers in nature to an act of money transfer from one entity to another, and it is obvious that a payment method will be valued as long as the transaction can be completed with safety no matter what technology was used. The key to U-payment is convenience and security in the transfer of financial information. The purpose of this paper is to find a desirable U-payment scheme by looking at the characteristics of seamlessness under the ubiquitous environments, strong personal device, and peer-based information transactions. We also propose U-SDT Protocol integrating technologies such as Radio Frequency Identification (RFID), Bluetooth, Personal Payment Device, Account Managing Application and Transaction ID as a way to make transactions between users seamless and secure better privacy protection.

• Korean Journal of Computational Design and Engineering
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• v.21 no.3
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• pp.215-223
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• 2016

The low price around 1000 USD makes consumer 3D printers as a new additive manufacturing platform for the personal manufacturing where consumers can make and sell their own products. To allow the consumers to design and manufacture their products, not only economic 3D printers but also supporting information systems for their design and manufacturing are essential. This study suggests an extended product data management (PDM) system that can support both the design and manufacturing of personal products with consumer 3D printing services. This extended PDM system helps consumer designers use advanced PDM technologies for their design and connected 3D printing services with Internet of Things (IoT) technology for realization of their products. As a result, the proposed system supports the consumer designers a seamless integrated product development and manufacturing environment supported by PDM and consumer 3D printing services.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.460-467
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• 1998

The investigation deals with the manufacturing process design and deformation analysis for seamless pressure vessels Axisymmetric multistage deep drawing is a complex and important sheet metal forming process in the industry. In this study the process design for large size cylindrical shells with various thickness is performed and a general guideline for forming process design of pressure vessels will be suggested. Thus in this paper for the verification of the forming process design the forming analysis of pressure vessels will be carried out by PAM-STAMP which is on the basis of finite element analysis. In this case the formability of pressure vessels is evaluated using the results of computer simulation.

• Korean Journal of Computational Design and Engineering
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• v.14 no.4
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• pp.281-289
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• 2009

Topology optimization has been widely used for the optimal structure design for weight reduction and high performance. Since the result of three-dimensional topology optimization is represented by the discrete material distribution in finite elements, it is hard to interpret from a design point of view. In this paper, the method for interpreting three-dimensional topology optimization resuIt into a series of cross-sectional curve representation is proposed and interfaced with the existing CAD system for the practical use. The concept of node density and virtual grid is introduced to transform element density values into grid density and material boundaries in each cross section are identified based on the element volume rate to satisfy the amount of material specified in the original design intent. Design exampIes show that three-dimensional topology result can be converted into a form of curve CAD model and the seamless interface with CAD software can be achieved.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2003.05a
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• pp.135-138
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• 2003

Skin, the complex membrane that holds the body together, also embraces the full spectrum of design today-from product to architecture, fashion, and media. Every object has a skin. thick or thin, smooth or rough, porous or impermeable, the skin is the line between a hidden interior and an exterior we experience. Skin： Surface, Substance and Design is a compendium of products, furniture, fashion, architecture and media that expand the limits of what we understand as surface. Reflecting the convergence of natural and artificial life, this provocative a thesis shows how enhanced and simulated skins appear everywhere in today's world.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.4
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• pp.399-422
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• 2009

Although current wireless mesh network (WMN) applications experience a perceptually uninterrupted hand-off, their throughput after the hand-off event may be significantly degraded due to the low available bandwidth of the mobile client's new master. In this paper, we propose a novel mobility management scheme for 802.11-based WMNs that enables both seamless hand-off for transparent communications, and bandwidth awareness for stable application performance after the hand-off process. To facilitate this, we (i) present a new buffer moment in support of the fast Layer-2 hand-off mechanism to cut the packet loss incurred in the hand-off process to zero and (ii) design a dynamic admission control to grant joining accepts to mesh clients. We evaluate the benefits and drawbacks of the proposal for both UDP and TCP traffic, as well as the fairness of the proposal. Our results show that the new scheme can not only minimize hand-off latency, but also maintain the current application rates of roaming users by choosing an appropriate new master for joining.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.163-175
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• 2006

This paper provides a corporation's marketing strategy under a ubiquitous computing environment: a WOM(word-of-mouth) marketing using RFID(Radio Frequency Identification) technology and a business model which facilitates the word-of-mouth marketing. To this end, we examine the word-of-mouth communication effects on consumers' life, changes in corporations' attitude toward word-of-mouth marketing, and the difficulties that corporations have in conducting word-of-mouth marketing. The business model this paper suggests makes seamless business-to-consumer and consumer-to-consumer networking possible using the RFID technology and facilitates the word-of-mouth marketing through incentive system of each economic player.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.155-160
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• 2011

IPTV functions not only as media player that does play the broadcasting industry's contents, also as the gateway is guaranteed of QoS(Quality of Service). This is for free contents-sharing that device stores contents using home network circumstance, and is for watching with seamless network service. Also this have required next QoS model that can handle stably as it may contain more data of the small computing device in next generation home system. We need ubiquitous-oriented QoS's design and development project that focuses on internal and external media service, not the existing QoS nor one-sided QoS of media sevice industry. This paper focuses on network module development. This supports IPTV in media industry and two-way capability of QoS highlighting multimedia service in network industry. In additional, this can handle stably the multiplex signal of USN/RFID as the representative ubiquitous and home network that services high-speed wire and wireless interface, and support the seamless u-QoS.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.240-243
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• 2004

Recently, in the global and digital business environment, we are in need of a single window through which we can exchange market information, make a contract, exchange foreign currency, clear customs and settle accounts. The "e-Trade platform" provides all the stakeholders in international trading circles with these series of trading processes by use of any available information technologies in an effective and seamless manner. The platform collectively includes e-trade infrastructures(e-trade documents repository, e-trade messaging system, e-trade standard documents repository) enabling small and medium sized companies as well as large enterprises to interface with government organizations and global trading institutions. The IT levels of the trading companies are significantly important in terms of benefiting the quality services from the e-trade platform.