• Journal of applied mathematics & informatics
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• v.9 no.1
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• pp.101-124
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• 2002

The convergence rate of a numerical procedure barred on Schwarz Alternating Method (SAM) for solving elliptic boundary value problems (BVP's) depends on the selection of the interface conditions applied on the interior boundaries of the overlapping subdomains. It hee been observed that the Robin condition(mixed interface condition), controlled by a parameter, can optimize SAM's convergence rate. Since the convergence rate is very sensitive to the parameter, Tang[17] suggested another interface condition called over-determined interface condition. Based on the over-determined interface condition, we formulate the two-layer multi-parameterized SAM. For the SAM and the one-dimensional elliptic model BVP's, we determine analytically the optimal values of the parameters. For the two-dimensional elliptic BVP's , we also formulate the two-layer multi-parameterized SAM and suggest a choice of multi-parameter to produce good convergence rate .

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.1005-1014
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• 2010

When reader collect tags, we found that they tend to get together to specific interface in Multi-Interface Multi-Channel 2.4GHz Active RFID system. To solve this problem, we designed the LP-Combind and AP-Balanced protocol for load distribution between interfaces, then verified its superiority of the performance through the simulation. There are three problems to implement designed protocols in hardware of firmware-level. first, tag selects randomly the channel of reader and reader need the method which can change the channel of tags. second, reader has the synchronization problem between reader and tag. third, reader has problem that MCU of reader have to operate simultaneously dual interface. To slove this problems, we designed the message and implemented method for tag channel change and the protocol in order to adjust synchronization between reader and tag, Therefore, we compared and analyzed the performance of protocols by experiment. If LP windows size is same, the performance of LP-Combined protocol and AP-Balanced protocol which lower collision probability by its load distribution is more outstanding than single interface protocol performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.348-357
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• 2012

Recently, smartphone, notebook, PC and other supporting wireless LAN device have come into wide use. By increasing user that use wireless LAN device, wireless traffic also increased. If wireless traffic through one AP is increase, it causes throughput decrease. To solve this problem, wireless LAN service provider install more AP where overload occurred. But this is not enough. Because stations can't know AP's load factor, and APs do nothing for load balancing. In this paper, we propose Multi-Interface Access Point(MIAP) to solve this problem. MIAP operate same as multiple APs with multi-interface, and MIAP measure each interface's load periodically. If MIAP detect overloaded interface, MIAP transfer station from overloaded interface to under-loaded interface. We conducted an experiment for verifying existing problem, and we found this problem occurred. We plan an experiment scenario for a comparison between existing AP and MIAP, and excute these experiment. In the result, we show MIAP with load balancing can improve total throughput about 72% and stabilize delay jitter than existing AP.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.467-474
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• 2000

The application of Terzaghi's theory of consolidation for analysing the settlement of multi-layered soils is not strictly valid because the theory involves an assumption that the soil is homogeneous. The settlement of stratified soils with confined aquifer can be analysed using numerical techniques whereby the governing differential equation is replaced by 2-dimensional finite difference approximations. The problems of discontinuous layer interface are very important in the algorithm and programming for the analysis of multi-layered consolidation using a numerical analysis, finite difference method(F.D.M.). Better results can be obtained by the process for discontinuous layer interface, since it can help consolidation analysis to model the actual ground The purpose of this paper provides an efficient computer algorithm based on numerical analysis using finite difference method(F.D.M) which account for multi-layered soils with confined aquifer to determine the degree of consolidation and excess pore pressures relative to time and positions more realistically.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.63-66
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• 2003

It is experimentally shown that a $TiO_2$ film on Si(111) substrate was prepared by using the technique of D.C. reaction sputter deposition with $Ar^{+}$ ion beam bombardment, and a layer-like structure was observed from the depth profile of the interface between $TiO_2$ film and Si substrate with Scanning Electron Microscopy and Electron Probe. It was also surprisingly discovered that Ti atoms could be detected at about 9 $\mu$m depth. The $TiO_2$-Si interface bombarded by $Ar^{+}$ ion beams revealed multi-layer structures, a mechanism might be caused by defect diffusion, impurity and matrix relocation. Multi-relocations of impurity and matrix atoms were as a result of profile broadening of the $TiO_2$-Si interface, and the spread due to matrix relocation in this system is shown to exceed much more the spread due to impurity relocation.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.145-148
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• 1999

The ability to rapidly create and deploy new and novel services in response to market demands will be the key factor in determining the success of the future service provider. This goal may be approached from different directions. One of them is an open interface making the functionalities of a network element programmable and usable by outside entities. In this paper, we describe several aspects of this new, hot technical area and introduce related standard activities. In addition, we present a new switching system called MSMP (Multi-Service Multi-Plug-In), which is based on the open programmable interface concept, and describe its architecture and main functionalities of its components.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.299-311
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• 2005

This article introduces developing trends of an "Ubiquitous Interface" as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. "Ubiquitous Interface" is include a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These "Ubiquitous Interface" able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended candidates are RFID, NFC, Multi-mode mobile terminal, Wearable computer and OSGi for integrated digital home networking system as a future ubiquitous interface. These candidates are have to have flexibility and multiple physical communication channel for seamless service hand over and serve easy connection at huge USN to user. And, must have flexible software structure and multi-functional middleware. Consequently, for more enhance performance of an ubiquitous interface and developing, need more structured and integrated future plan.

• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.1-10
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• 2022

Traditional centralized radio access network architecture used for 4G is based on Option 8, a functional split between PHY and RF. This option is commonly used with a fronthaul interface based on common public radio interface (CPRI) specifications; however, the increased data rates in 5G make this option impractical because of the fronthaul interface's high bandwidth requirement. Since CPRI specifications have many vendor-specific options, achieving multi-vendor interoperability becomes challenging. Open RAN (O-RAN) Alliance is developing novel open fronthaul interface specifications based on the functional split Option 7-2x, one of the intra-PHY split options, to relax the bandwidth requirement of the fronthaul interface and achieve multi-vendor interoperability. This article provides a brief overview of the various functional split options for 5G fronthaul that have been reported so far and existing fronthaul technologies. Further, the technological trends in the 5G open fronthaul interface is discussed, focusing on the O-RAN Alliance specifications under standardization.

• The KIPS Transactions:PartC
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• v.18C no.2
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• pp.111-118
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• 2011

Recently, with the popularity of smartphones, an interest in multi-networking service through wireless multi-interface of a mobile node is increased. Also, wireless networking technology for using wireless multi-interface has been studied. As the related work, in the IETF Netext WG, the extension of PMIPv6 protocol for multi-interface support is being discussed. Existing PMIPv6 protocol includes the functions for simultaneous access over multi-interfaces of a mobile node and inter-technology handover between multi-interfaces of the mobile node. However, in case of the existing protocol, the problem occurs when inter-technology handover is performed after simultaneous access on the PMIPv6 domain, this problem is the discontinuous of simultaneous connections. Therefore, the PMIPv6 Protocol cannot support flow based multi-homing service. In this paper, as a way to solve the problem, Hybrid Home Network Prefix scheme is proposed.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.666-671
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• 2006

'Multi modal 인터페이스'란 인간과 기계의 통신을 위해 음성, 키보드, 펜을 이용, 인터페이스를 하는 방법을 말한다. 최근 들어 많은 휴대용 단말기가 보급 되고, 단말기가 소형화, 지능화 되어가고, 단말기의 어플리케이션도 다양해짐에 따라 사용자가 보다 편리하고 쉽게 사용할 수 있는 입력 방법에 기대치가 높아가고 있다. 현재 휴대용 단말기에 가능한 입력장치는 단지 단말기의 버튼이나 터치 패드(PDA 경우)이다. 하지만 장애인의 경우 버튼이나 터치 패드를 사용하기 어렵고, 휴대용 단말기로 게임을 하는데 있어서도, 어려움이 많으며 새로운 게임이나 어플리케이션 개발에도 많은 장애요인이 되고 있다. 이런 문제점들은 극복하기 위하여, 본 논문에서는 휴대용 단말기의 새로운 Multi Modal 인터페이스를 제시 하였다. PDA(Personal Digital Assistants)를 이용하여 더 낳은 재미와 실감을 줄 수 있는 Multi Modal 인터페이스를 개발하였다. 센서를 이용하여 휴대용 단말기를 손목으로 제어를 가능하게 함으로서, 사용자에게 편리하고 색다른 입력 장치를 제공 하였다. 향후 음성 인식 기능이 추가 된다면, 인간과 인간 사이의 통신은 음성과 제스처를 이용하듯이 기계에서는 전통적으로 키보드 나 버튼을 사용하지 않고 인간처럼 음성과 제스처를 통해 통신할 수 있을 것이다. 또한 여기에 진동자를 이용하여 촉감을 부여함으로써, 그 동안 멀티 모달 인터페이스에 소외된 시각 장애인, 노약자들에게도 정보를 제공할 수 있다. 실제로 사람은 시각이나 청각보다 촉각에 훨씬 빠르게 반응한다. 이 시스템을 게임을 하는 사용자한테 적용한다면, 능동적으로 게임참여 함으로서 좀더 실감나는 재미를 제공할 수 있다. 특수한 상황에서는 은밀한 정보를 제공할 수 있으며, 앞으로 개발될 모바일 응용 서비스에 사용될 수 있다.