• Korea Trade Review
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• v.44 no.1
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• pp.87-99
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• 2019

Recently there are sharp increase in number of studies related with facilitation of Inward-FDI or Multinational Enterprises invested in Korea region. The most of studies are mainly purposing to survey - 1)how Korea Government makes counter plan and assistance policy to make foreign capital and Inward-FDI more attractively and aggressively, 2)what is the new framework or system for Inward-FDI policy, 3)what is economic effect of Inward-FDI, 4)what are determinants or conclusive factors of FDI in Korea. Under this situation, the goal of this report is to find out the new way for Multinational Enterprises to reinvest continuously thru getting their better investment performances on several factors including Marketing Competence, Management Ability, Localization Management Skill, Business Management Strategy, and R&D Competitiveness which would be much more important determinants influencing re-investment of Multinational Enterprises in Kora. This report based on the empirical result and comprehensive analysis will eventually help policy makers to implement the appropriate strategy and support Multinational Enterprises to proceed positive circle's re-investment activity in the end.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.334-337
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• 2010

디지털 선박 운행시 예기치 못한 상황에 의한 선박 내 화재나 충돌 등 긴급 상황 발생 시에 대형의 해난 사고가 발생할 수 있다. 이에 본 논문에서는 선박 상태를 자체 진단하여 모니터링하고 위험 분석을 통해 관리할 수 있는 시스템을 구현하고자 한다. 해양 디지털선박의 환경, 상황을 수집할 수 있는 무선 센서를 이용하여 수집된 환경 정보를 분석하는 시스템을 제안하였으며, 센싱된 데이터를 분석하기 위하여 역전파 신경망을 설계하였다. 300개의 데이터 집합을 사용하여 역전파 신경망을 실험한 결과 약 96%의 정확도를 가졌다. 제안된 시스템은 하드웨어 (UStar-2400 ISP, UStar-2400, Wireless sensors) 부분과 소프트웨어 부분(User Interface module)으로 구성되며 소프트웨어 부분은 HOST PC에 삽입된다. 그리고 시스템의 정확도를 개선하기 위하여 전방향 에러 정정 시스템(LDPC)을 구현하였고 진단된 결과는 CDMA 방식으로 전송하여 해양디지털선박 감지 모니터링 시스템을 구현했다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.21-22
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• 2009

유비쿼터스 사회(Ubiquitous Society)로의 진입에 발맞추어 USN(Ubiquitous Sensor Network) 기반의 인간 중심적 편의 시스템에 관한 연구가 활발하게 진행되고 있다. 그 중 대형 시장을 갖는 차량 편의시설에 관한 연구는 지능형 차량 시스템(Intelligent Car System)을 중심으로 활발히 이루어지고 있다. 지능형 차량 시스템의 주요 연구는 자동 항법 장치, 사고 예방 장치, 자가 진단 시스템 등 탑승자의 편의성과 안전성을 중심으로 진행되었다. 그러나 탑승자의 사고 발생 시 응급 상황 처리를 위한 지원 시스템은 미미하다. 탑승자 부상으로 사고 신고를 하지 못할 경우, 사고지점 확인, 탑승자의 위급(현재) 상황, 부상 정보와 같은 정보를 얻을 수 없어 응급 상황 대처에 신속하지 못할 수 있다. 따라서 본 논문은 다양한 센서를 이용하여 차량의 정보를 수집하고, 사고 판단 시 차량 위치 정보, 탑승자 상황 정보를 응급 기관에 전달할 수 있는 차량용 스마트 안전장치를 설계 및 구현하였다. 테스트를 위해 Intel PXA255 MCU와 AM-3AXIS(3축 가속 센서), MDSM-1000A(지자기 센서), RX-M800S CDMA, GPS520, Alpha cam, Flex Sensor로 시스템을 제작하였으며 모의 도로 모형에서 테스트 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1224-1227
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• 2008

송변전자동화시스템에서 사용하는 주장치 와 RTU간에는 무선 통신망으로 TRS(Trunked Radio System), CMDA(Code Division Multiple Access) 그리고 에어미디어망을 사용하고 있다. 특히 디지털 TRS기술인 유럽 전자 통신 표준기구인 ETSI에서 개발한 TETRA는 임대망인 CDMA와 에어미디어망과는 달리 비임대망으로 비용적인 장점을 가지고 있다. 본 논문은 송변전자동화시스템에서 주장치 기능을 하는 DNP3.0 주장치 서버와 RTU의 기능을 하는 FRTU간에 TETRA 망을 사용할 수 있도록 MFTG(Multi Function Tetra Gateway) Platform을 구현하였다.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1023-1026
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• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2100-2112
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• 2011

An orthogonal code hopping multiplexing (OCHM) technique has been proposed for accommodating a large number of users with low channel activities than the number of orthogonal codewords through statistical multiplexing in downlink cellular systems. In this paper, a multiple input multiple output (MIMO) antenna based OCHM system is proposed to improve the performance. Each modulated symbol is repeated N times and the N repeated symbols are transmitted simultaneously using N transmit antennas. Through repetitions, the effect of perforations that the OCHM system experiences is decentralized among the repeated symbols and the full perforation probability is significantly reduced. Each receiver detect the transmitted signal using its pre-assigned code hopping pattern. Simulation results show that the proposed scheme saves the required energy for a given frame error rate (FER).

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.93-99
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• 2010

Since the facility management for various facilities in urban area are conducted by general managers who have poor knowledge for surveying technology, it is not easy to trace the exact location of the facility in a short time with the GIS map only by themselves in the field. In order to improve it, VRS-RTK or SBAS DGPS system integrated with UMPC and PDA which is uploaded GIS field software are being used recently however lot of difficulties are still existed with the GPS positioning in urban area due to the lack of visible satellites, no reception of correction data and multipath error by the interruption of the high buildings and houses etc. Therefore, in this study, we applied with Network DGPS system which allows better reception of satellite signal and correction data even in dense housing areas with the use of GNSS receiver and CDMA mobile phone. Based on the analysis of field data, it was confirmed that standard deviations of the Network DGPS positioning are 0.3 to 0.84m with a very high positioning rate even in dense housing areas. Therefore, it was concluded that the Network DGPS system could be used widely to fast and accurate positioning for various facilities management works in dense housing areas in the future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.600-613
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• 1997

The implementation of a BTS(Base station Transceiver) for WLL system using W-CDMA(Wideband-Code Division Multiple Access) method is presented in this paper. It consists of three boards; receiver, transmitter and RF controller. Some RF parameters are considered and simulated by the RF simulation S/W using commercial and customized components specifications. The implemented transceiver of 5 MHz RF channel bandwidth satisfies the system requirements of a transceiver such as dynamic range, sensitivity in the receiver and spurious emission suppression in the transmitter. At the receiver, the experimental measurement showed 2.86 dB of NF and 60 dB above of dynamic range in AGC(Automatic Gain Control) locking. At the transmitter, the -49.46 dBc of spurious emission suppression is attained when the output power of the transmitter is 34.3 dBm. These results are good enough to meet to standard performance specifications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.947-955
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• 2002

In this paper, we derive an outage probability for the Erlang capacity and the link margin respectively, calculate them with the same parameters and outage probability, and then analyze a capacity and cell coverage in city, suburban, and open area. So, the Erlang capacity is more real than in a cell, and the cell coverage can be calculated with high reliability by the margin. When the $E_b/N_o$ decreases from 7 dB to 5 dB within the outage probability of 5 %, it is observed that the capacity is increased from 18 Erlang to 31 Erlang with the same margin of 2.8 dB, then the coverage is increased to 0.4 km, 1 km, and 2.5 km in city, suburban, and open area respectively. Also if the outage probability is decreased from 5 % to 2 % in case of $E_b/N_o$ of 5 dB, the result shows a very reliable link with additional increment of 0.88 dB in the margin and a high QoS (quality of service) within decrement of 0.15 km, 0.5 km, and 1.5 km for the same areas with decrement of 3 Erlang from 31 Erlang.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.195-202
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• 2002

Recently, as the range of mobile communication services is extended, the interference between adjacent base-stations is increased. Nowdays, one of the important factors causing interference is IMD (Inter-Modulation Distortion) problems. Not only active IMD but also passive IMD effects must be considered to design a CDMA system. In this study, we design and implement 7/16" DIN connectors which have a various intensity of surface illumination, thickness and quality of plating material to analyze the effects of PIMD. And propose the methods for improving the PIMD characteristics: First, it is more profitable to use the metal which has good intensity of surface illumination where most of all electric currents passes through it. Secondly, we should plate metals more than $5{\mu}m$ for RF energy enough to propagate in a medium. Thirdly, it is necessary to select a metal having high conductivity and specific heat to protect the aging phenomenon of plate material. And it is required to develop a new plating material to replace the current materials, such as the alloy of three components for cost reduction. We have to know that the plate which has intensity of surface illumination 6 S and the thickness of plating material $5{\mu}m$ satisfy the domestic PIMD specification (KTF) -150 dBc, regardless of the plate material in case of 7/16" DIN connector.