• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.154-161
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• 2018

As the number of smartphone users increases, research on indoor location recognition service is necessary. Access to indoor locations is predominantly WiFi, Bluetooth, etc., but in most quarters, WiFi is equipped with WiFi functionality, which uses WiFi features to provide WiFi functionality. The study uses the random forest algorithm, which employs the fingerprint index of the acquired WiFi and the use of the multI-value classification method, which employs the receiver signal strength of the acquired WiFi. As the data of the fingerprint, a total of 4 radio maps using the Mac address together with the received signal strength were used. The experiment was conducted in a limited indoor space and compared to an indoor location recognition system using an existing random forest, similar to the method proposed in this study for experimental analysis. Experiments have shown that the system's positioning accuracy as suggested by this study is approximately 5.8 % higher than that of a conventional indoor location recognition system using a random forest, and that its location recognition speed is consistent and faster than that of a study.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.360-365
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• 2014

There are many types of advanced devices for weather prediction process such as weather radar, satellite, radiosonde, and other weather observation devices. Among them, the weather radar is an essential device for weather forecasting because the radar has many advantages like wide observation area, high spatial and time resolution, and so on. In order to analyze the weather radar observation result, we should know the inside structure and data. Some non-precipitation echoes exist inside of the observed radar data. And these echoes affect decreased accuracy of weather forecasting. Therefore, this paper suggests a method that could remove line-shaped non-precipitation echo from raw radar data. The line-shaped echoes are distinguished from the raw radar data and extracted their own features. These extracted data pairs are used as learning data for naive bayesian classifier. After the learning process, the constructed naive bayesian classifier is applied to real case that includes not only line-shaped echo but also other precipitation echoes. From the experiments, we confirm that the conclusion that suggested naive bayesian classifier could distinguish line-shaped echo effectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.1027-1032
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• 2015

Using the radio wave, RFID(: Radio Frequency IDentification) wirelessly transmits the unique information saved in a tag attached on the specific object. In the construction area, the trend in using RFID for managing the input and inventory of the construction materials is upward. General management systems for the construction materials have only a function of identifying the tag attached on the construction materials, but the management system with a function of identifying and managing the location information of the construction materials employing RFID, for reusing it, is not actively developed. For the efficient reuse of the construction materials, in this paper, we propose the RFID system with a function of estimating and saving the location information of the specific construction materials, based on the estimated distances between the particular subs and reader. The proposed system consists of RFID reader, distance estimate, communication, and memory units.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.10
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• pp.965-970
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• 2012

In this study, the water distribution in the cathode side of a direct methanol fuel cell (DMFC) is visualized using a neutron imaging technique at the Neutron Radiography Facility (NRF), KAERI. It is difficult to quantify the water content in the cathode side because of $CO_2$ gas. A compared open circuit voltage (OCV) image, relative $CO_2$, and water distribution can be visualized by the neutron imaging technique. This means that the neutron imaging technique is useful for the optimization of the flow field design and the establishment of water management, and, in turn, for the improvement of the cell performance.

• Development and Reproduction
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• v.4 no.1
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• pp.29-35
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• 2000

A phosphatidylinositol 3-kinase (PI3K) is a upstream component of insulin signaling by which protein synthesis can be stimulated in many systems. To elucidate involvement of PI3K and its downstream mammalian target of rapamycin (mTOR) in the insulin signaling in pleimplantation mouse embryos, 8-cell embryos were cultured to blastocysts in the presence or absence of insulin and／or inhibitor drugs. The number of blastomeres per blastocyst, protein synthesis, and protein phosphorylation were examined. There was significant difference in embryonic development to blastocyst stage and hatching was potentiated by the insulin supplementation. The increase in the mean celt numbers per blastocyst was apparent in the insulin culture. Wortmannin, a PI3K inhibitor and rapamycin, an inhibitor of mTOR abolished the stimulatory effect of insulin on morphological development mitosis and protein synthesis. In autoradiography, phosphoproteins pp22 and pp30 which undergo phosphorylation in response to insulin were identified. Taken together, it can be suggested that PI3K and mTOR engaged in insulin signaling in the mouse embryo 8-cell onward and mediate embryotropic offset of insulin.

• Journal of Korean Society of Disaster and Security
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• v.9 no.1
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• pp.33-38
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• 2016

Real time location system was development for safety management at road and bridge maintenance field. The system can check the real-time location detection, movement history, behavior of a number of laborers. The system consisted of a Bluetooth and ZigBee that uses low-power. It had a very large error that the previous method for the position recognition by triangulation using the RSSI. Because This study proposed a new distance measurement and correction scheme using RSSI and accelerometer. It was evaluated in the maintenance field. A development system were evaluated in the field, the results are shown an error between 0.2 m and 0.4 m. And through the acceleration of history it was confirmed by determining possible to determine the safety situation of the laborers.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.329-338
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• 1999

In this paper we propose a WATM MAC protocol called DTDD/PS (Dynamic Time Division Duplex using Poll/Select scheme). The idea of the DTDD/PS protocol is based that a radio cell is considered as queueing system. The MAC controller in base station is charged in coordinating terminals for the QoS requirement from each terminal. For that reason, terminals send it's own dynamic parameter represented its status, and controller controls the access of terminals and assigns time slots dynamically using received parameters. Therefore this system can satisfy the QoS of real-time service in wireless environments. To evaluate DTDD/PS protocol simulations are executed. In 25Mbps channel capacity, the voice and data coexist traffic situation, as the total number of terminal is increased, the delay of data terminals is increased rapidly. But the case of only increasing data terminals, the number of supported voice terminals is not varying. Therefore we can expect that DTDD/PS protocol can applied to multimedia traffic effectively.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.877-882
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• 2005

It is necessary that Fail-Safe Seaway technology providing a continuous navigation solution though fault of navigation system is occurred in sea. This paper focus on signal processing of GPS receiver, one of receivers using the software radio technology to implement a integrated radio navigation system including satellite-based and ground-based navigation systems. It is difficult to implement the software GPS receivers using a commercial processor because of the heavy computational burden for processing the GPS signals in real time. This paper proposes an efficient multi-bit GPS signal processing scheme to reduce the computational burden for processing the GPS signals in the software GPS receiver. The proposed scheme uses a compression concept of the multi-bit replica signals and patterned look-up table method to generate the correlation value between the GPS signals and the replica signals.

• Journal of Korean Public Health Nursing
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• v.14 no.1
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• pp.61-67
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• 2000

뉴욕시 정부의 이민자들에 대한 다각적인 접근과 시도에도 불구하고 의료 서비스 제공자들과 대상자간에 언어적 장벽과 문화적 차이로 인한 상호협조의 어려움은 계속되고있다. 본 연구는 뉴욕시 보건국 소속 다민족 다문화 계층의 의료수준 향상을 위한 노력의 일환으로 실시된 프로젝트 중 일부이다. 뉴욕시의 한국 이민자들이 뉴욕시에서 증가하는 추세를 감안할 때, 이들의 의료시설 이용 및 서비스 수혜에 대한 기초 조사를 실시하여 한국 이민자들의 문화적 배경과 그로 기인한 건강 신념을 알고자하는 시 정부 차원의 요구가 이 연구의 배경이다. 즉, 한국이민 사회의 독특한 특성을 뉴욕시 정부 관련 의료서비스 제공자들에게 그 이해를 높여서 한국 이민자들의 미국에서의 의료서비스 수혜의 기회를 높이고자 한 것이다. 기초 관련 연구가 전무한 한국 이민자들의 건강관련 이슈를 다루기 위해 미국 센서스와 병원 입퇴원 기록 현황에 나타난 한국인 혹은 아시안의 의료보장 실태 등을 고찰하였고, 한국이민사회의 주요 기관의 대표들과의 면담과 이민자들을 대상으로 한 직접 설문조사로 자료를 수집하여 분석한 결과는 다음과 같다. 한국 이민자들은 한국어를 주요 언어$(83\%)$로 사용하는 것으로 나타나 문화의 동화율이 낮았고, 낮은 문화 동화율은 의료 서비스 접근도를 낮추는 요인으로 나타났다. 또한, 의료 보험이 없는 것$(55\%)$이 가장 큰 요인으로 지적되었는데, 이는 미국 직장에 적응하기 어려운 이민생활로 자영업을 주로 하는 생활 양태가 비싼 사 보험(private health insurance)을 사지 못하는 요인과 관련되어있다고 본다. 따라서, 주로 이용하는 의료 서비스의 종류에도 많은 제한점이 있어서, $60\%$가 한국인 의사를 선호하며, $31\%$가 한국인 약사에게 건강관리를 의존하는 것으로 나타나 미국사회의 의료 서비스 접근도는 극히 취약한 것으로 드러났다. 의료서비스 접근을 막는 주요 장벽으로는 비싼 의료비 $(53\%)$ , 의사소통장애$(37\%)$로 나타났다. 보건의료 서비스를 위해 주로 이용하며 생활의 정보를 얻는 통로로는 한국어 신문$(69\%)$과 한국어 TV$(61\%)$, 한국어 라디오 $(57\%)$로 밝혀졌다. 결론적으로 한국 이민자들에게 좀더 나은 의료 서비스 수혜를 위해서는 문화 친밀도가 높은 의료환경 조성 및 의료 서비스 제공자들의 이해를 높이는 일 등과 함께 한국 이민자들이 의료보험을 살수 있도록 한국어로 된 의료 서비스 정보를 제공하는 등의 노력이 필요할 것으로 생각한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.12
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• pp.1201-1208
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• 2016

Radio Frequency Identification (RFID) technology has a significant attraction throughout various industry sites, along with the development of wireless communication technologies. The typical applications of RFID include medical, logistics, and distribution, and, specially, it is effectively applied to non-contact environments, because it employs radio waves. Although, recently, construction cases of the RFID management systems for the inventory management of the construction materials have been increased, the related researches and experiments for the reused materials are not actively performed. In this paper, we propose the RFID system with the localization function for effectively managing the reuse of the construction materials, adding to the conventional inventory management system. The proposed system consists of a RFID reader unit and a receiver unit, and the location information of the material with the attached RFID tag is obtained by estimating the position of a RFID reader. The distance value for estimating the reader position is calculated using the Received Signal Strength Indicator (RSSI) value of Zigbee, and the performance evaluation of the proposed system is performed in the indoor space of $5m{\times}5m$.