• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.59-66
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• 2010

In this paper, we compare the performance of proposals for route optimization handover, which provides optimized communication to mobile node, presented in IETF (Internet Engineering Task Force). For comparison, we consider the architecture with two MAGs (Mobile Access Gateways) and single LMA (Local Mobility Anchor), and analyze the signaling cost, handover latency, and packet loss. Evaluation results show that they are changed depending on the involved component, the number of route optimization messages and performance factor that each proposal targets.

• Tuberculosis and Respiratory Diseases
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• v.38 no.3
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• pp.297-303
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• 1991

Subacute necrotizing lymphadenitis is characterized by cervical lymphadenpathy in young patients and mistaken for malignant disease both clinically and histologically. Microscopically, there is a varying degree of effacement of the lymph node architecture and necrosis with an infiltrate of histiocytic cells and absence of polymorphs. We have experienced 4 cases of cervical lymphadenopathy accompanied by fever. All cases had complete recovery to conservative treatment only. The excised lymph nodes were moderately enlarged and typically showed varying degree of necrotizing lesions, and abundant karyorrhectic debris, scattered fibrin deposits, aggregates of large mononuclear cells, and a paucity of plasma cell and neutrophils. For investigating the etiology and pathogenesis of this lesion, further clinical study and stepwise pathologic and immunologic planning would be valuable.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.3
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• pp.132-139
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• 2002

The implementation of passive optical network in the access network will result in design of the network that have characteristics of broadband, long distance transmission, transparency. Particularly, optical technologies of WDM and WGR have made a new access network of WDM-PON. This paper proposes the algorithm that determines structural elements of a survivable optical access network, and simulates the cost of various scheme of proposed network architectures. Our results show that multistage star is the most cost effective scheme than the other architectures and show that network architecture designed by proposed algorithm provides survivability with single link and 1st node failure.

• Journal of Korea Spatial Information System Society
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• v.2 no.1 s.3
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• pp.63-72
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• 2000

The architecture of the National Geo-spatial Information Clearinghouse Network (NGICN) is suggested in this paper. We described the function and relationship of six elements of the NGICN. The elements are clearinghouse network gateway, clearinghouse node, geo-spatial data server, communication network, protocols and standards, and clients. The NGICN suggested in this research will prevent the duplication and improve the value of the database, and persuade the institutes or enterprises in the private sector to participate in producing the geo-spatial database. Finally it will setup the business of producing, circulating and utilizing the geo-spatial information as a new bases of Info-Communication Industry.

• KIEAE Journal
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• v.13 no.2
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• pp.151-156
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• 2013

This study examines the properties of spaces where historical and cultural resources have been preserved in the street system of Daegu Yakryeong market district, by using Space Syntax methodology. The results were obtained through ASA(Angular Segment Analysis) on each node (spatial unit) in the street network. An overall characteristic of spatial configuration in street system of the surveyed district is that nodes in the street network tend to form socially integrated spatial structure to allow easy access to each space in the system. There are a small number of socially isolated spaces in the street system, which are located at nodes in narrow streets adjacent to the roadway outside the district, or in narrow alleys between early modern Korean buildings. More than half of the surveyed spaces have high levels of social integration, which contain buildings playing a central role of the community, a traditional street market, symbolic landmarks. In conclusion, it is expected that the achievements of this study will contribute in leading to rational land use planning for sound and sustainable development of historical and cultural resources in an urban district.

• Information and Communications Magazine
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• v.11 no.4
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• pp.62-70
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• 1994

This paper discusses the LAN interface technics physically applicable to the ISDN exchange system through frame relay without changing of the basic exchange architecture. To ensure the success of frame relaying, it's interworking with the existing X.25 services is very imported, and for this purpose both X.75 and 1.122-based interworking alternative must be considered. Definition required to frame relay, interconnection of remote bridge and ways to design the Frame Handler carrying a frame realying in the ISDN node was introduced here. Subsequently, alternatives using the X.25 and X.75 or 1.122 as well as interconnection mechanism LAN and ISDN for the LAN interface and LAN and/or LAN interface and ISDN through frame relay was individually introduced. Through frame relay applications in the major countries, the achievement of high speed frame relaying service to the LAN was introduced.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.89-101
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• 2006

This paper addresses Electrical Power Subsystem(EPS) design and verification of HAUSAT-2 small satellite through energy balance analysis(EBA) depending on individual operation modes. GaAs solar cells are used for satellite power generation and digital peak power tracking is implemented for EPS architecture. One battery pack is consisted of 4 Li-Ion cells. Battery charge is accomplished by peak power tracker and battery charge regulator. Power conditioning assembly uses three DC-DC converters, and power distribution assembly which consists of commercial IC and MOSFET switch distributes power to subsystems and payloads. The altitude of 650km and sun-synchronous LEO with various local time ascending node(LTAN) are considered in EBA.

• Structural Engineering and Mechanics
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• v.22 no.4
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• pp.483-510
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• 2006

The dynamic instability characteristics of laminated composite stiffened shell panels subjected to in-plane harmonic edge loading are investigated in this paper. The eight-noded isoparametric degenerated shell element and a compatible three-noded curved beam element are used to model the shell panels and the stiffeners respectively. As the usual formulation of degenerated beam element is found to overestimate the torsional rigidity, an attempt has been made to reformulate it in an efficient manner. Moreover the new formulation for the beam element requires five degrees of freedom per node as that of shell element. The method of Hill's infinite determinant is applied to analyze the dynamic instability regions. Numerical results are presented to demonstrate the effects of various parameters like shell geometry, lamination scheme, stiffening scheme, static and dynamic load factors and boundary conditions, on the dynamic instability behaviour of laminated composite stiffened panels subjected to in-plane harmonic loads along the boundaries. The results of free vibration and buckling of the laminated composite stiffened curved panels are also presented.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.87-96
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• 2006

Wireless Sensor Network (WSN) is researched in various filed. Underwater Sensor Network (UWSN) is used various purpose such as underwater environment monitoring. But, WSN is researched in the terrestrial that uses mainly radio frequency, The existing terrestrial research is incongruent to apply to underwater. Therefore, we propose UWSN architecture that considers underwater environment. In this paper, UWSN applied cluster technique and functional node constructs. Each cluster collects and sends cluster data. Dual super cluster head receives cluster data and transmits each in the base-station. We implement WSN routing algorithm, and construct test-bed and analyze cluster data receive rate.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.59-68
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• 2015

Traditional structure analysis method is based on numerical matrix analysis to use the geometries consisting of the structure. The characteristics require a lot of computer memories and computational time. To avoid these weaknesses, new approach to analyze truss structure was suggested by adopting topological load redistribution method. The axial forces to be not structurely analyzed yet against outside loads were redistributed by using nodal equation of equilibrium randomly at each node without constructing global matrix. However, this method could not calculate the axial forces if structure is statically indeterminate due to degree of many indeterminacies. Therefore, to apply the method suggested in this research, all redundancies of truss structure were replaced by unit loads. Each unit load could make the deformation of a whole structure, and a superposition method was finally adopted to solve the simultaneous equations. The axial forces and deflections agreed with the result of commercial software within the relative error of 1 %, whereas in the case that the axial forces are relatively very smaller than others, the relative errors were increased to 2 %. However, as the values were small enough not to be considered, it was practically useful as a structural analysis model. This model will be used for structural analysis of truss type of large structure such as agricultural farming facility.