• Title/Summary/Keyword: 강철원

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Design and Implementation of RSSI-based Intelligent Location Estimation System (RSSI기반 지능형 위치 추정 시스템 설계 및 구현)

  • Lim, Chang Gyoon;Kang, O Seong Andrew;Lee, Chang Young;Kim, Kang Chul
    • Journal of Internet Computing and Services
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    • v.14 no.6
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    • pp.9-18
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    • 2013
  • In this paper, we design and implement an intelligent system for finding objects with RFID(Radio Frequency IDentification) tag in which an mobile robot can do. The system we developed is a learning system of artificial neural network that uses RSSI(Received Signal Strength Indicator) value as input and absolute coordination value as target. Although a passive RFID is used for location estimation, we consider an active RFID for expansion of recognition distance. We design the proposed system and construct the environment for indoor location estimation. The designed system is implemented with software and the result related learning is shown at test bed. We show various experiment results with similar environment of real one from earning data generation to real time location estimation. The accuracy of location estimation is verified by simulating the proposed method with allowable error. We prepare local test bed for indoor experiments and build a mobile robot that can find the objects user want.

SDN-Based Middlebox Management Framework in Integrated Wired and Wireless Networks (유무선 통합망에서의 SDN 기반 미들박스 관리 프레임워크)

  • Lee, Giwon;Jang, Insun;Kim, Wontae;Joo, Sukjin;Kim, Myungsoo;Pack, Sangheon;Kang, Chul-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.6
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    • pp.379-386
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    • 2014
  • Recently, middleboxes play a key role in many network settings such as firewalls, VPN gateways, proxies, intrusion detection and prevention systems, and WAN optimizers. However, achieving the performance and security benefits that middleboxes offer is highly complex, and therefore it is essential to manage middleboxes efficiently and dynamically. In this respect, Software-Defined Networking (SDN) offers a promising solution for middlebox policy enforcement by using logically centralized management, decoupling the data and control planes, and providing the ability to programmatically configure forwarding rules. Also, cloud computing and distributed Network Function Virtualization (NFV) can enable to manage middleboxes more easily. We introduce SDN-based middlebox management framework in integrated wired and wireless networks and discuss the further issues.

A Study on Extraction of Irregular Iris Patterns (비정형 홍채 패턴 분리에 관한 연구)

  • Won, Jung-Woo;Cho, Seong-Won;Kim, Jae-Min;Baik, Kang-Chul
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.2
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    • pp.169-174
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    • 2008
  • Recently, biometric systems are of interest for the reliable security system. Iris recognition technology is one of the biometric system with the highest reliability. Various iris recognition methods have been proposed for automatic personal identification and verification. These methods require accurate iris segmentation for successful processing because the iris is a small part of an acquired image. The iris boundaries have been parametrically modeled and subsequently detected by circles or parabolic arcs. Since the iris boundaries have a wide range of edge contrast and irregular border shapes, the assumption that they can be fit to circles or parabolic arcs is not always valid. In some cases, the shape of a dilated pupil is slightly different from a constricted one. This is especially true when the pupil has an irregular shape. This is why this research is important. This paper addresses how to accurately detect iris boundaries for improved iris recognition, which is robust to noises.

Location Estimation Algorithm with TDOA Scheme in Real Time Location System (RTLS에서 TDOA 기법을 이용한 위치추정 알고리즘)

  • Jeong, Seung-Hee;Kang, Chul-Gyu;Oh, Chang-Heon;Lim, Choon-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.459-462
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    • 2005
  • In this paper, we investigate the high precision location estimation algorithm in 2.45GHz band RTLS with multiple tags. The location is estimated in LOS environments, 300m ${\times}$ 300m area, and 2D coordinates adopting a TDOA scheme which is not necessitate the transmission time of tags. We evaluate the average estimation error in distance assuming that tags are randomly distributed and the readers(3${\sim}$8) are uniformly(equal space) placed in test area. In results, average estimation error is 3.12m and 1.47m at reader numbers of 4 and 8, respectively. Minimum estimation error is obtained when the accumulated receiving signal from a tag is 3 or 4 regardless of available reader numbers. The error is less than 3m, satisfies the specification of RTLS.

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Noise Elimination Algorithm for Detecting Partial Discharge of Generator Stator Winding Considering Relation of Periphery Signals (고압 회전기 고정자 권선의 부분방전 계측 시 주변 신호 관계를 고려한 노이즈 제거기법)

  • Shin, Hee-Sang;Cho, Sung-Min;Kang, Chul;Kang, Dong-Sik;Cho, Kuk-Hee;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.9
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    • pp.17-24
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    • 2008
  • Recently, the importance of supplying the reliable electric power is increasing. therefore, the importance of diagnosis of power equipments is increasing also. Breaking insulation of stator windings is major cause of faults in high voltage generators. On-line PD (Partial Discharge) detection using Capacitive Coupler at stator windings is used widely to diagnose high voltage generator. However, precise PD(Partial Discharge) detection is impossible if detected signals are mixed with PD and noise signal. In this paper, we analyze detected signals using Capacitive Coupler at 13[kV] hydroelectric generator stator winding and suggest not hardware method but noise elimination algorithm for detecting PD of generator stator winding considering relation of periphery signals.

The Response of Parenchymal Mass and Airway Obstruction from Lung Cancer to Radiation Therapy (단순 흉부 X-선 사진상 폐암 소견에 대한 방사선 치료의 효과 -단기 추적 조사를 중심으로-)

  • Kang, Cheol-Hoon;Shin, Sei-One;Kim, Myung-Se
    • Radiation Oncology Journal
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    • v.7 no.2
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    • pp.227-233
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    • 1989
  • From April 1986 to Dec 1988, fifty one patients with carcinoma of lung were treated by radiation therapy in Department of Therapeutic Radiology, Yeungnam University Hospital Of the 51 patients, $31(61\%)$ were squamous cell ca, $8(15.7\%)$ were small cell ca, and remained $4(7.9\%)$ were other cell types. Total radiation dose was average $64Gy (60\~75 Gy)$ for group A and 45Gy $(40\~59Gy)$ for group B. The mass regression and the response of airway obstruction to radiation therapy was established on the basis of follow up chest X-ray. The mass regression above $50\%$ of total volume was noted in 23 patients $(74.2\%)$ among 31 patients and the difference between two groups was not seen. In squamous cell ca, however, the mass regression rate (above $50\%$ of total volume) was $83.3\%$ (10/12) in group A compared to $50\%$ (3/6) in group B(p<0.05). The alleviation of airway obstruction was noted as follows. In group A, CR $42.9\%$, PR $35.7\%$, no response $21.4\%$ and in group B, CR $55.6\%,\;PR\;33.3\%$, no response $11.1\%$. But, in squamous cell ca, responsiveness is higher than group B. The study indicates that the importance of higher radiation dose in the management of primary tumor mass and airway obstruction caused by lung cancer especially squamous cell ca. So, meticulous treatment planning and multimodality combination therapy without increasing si.do elect or complication is recommended in management of inoperable bronchogenic carcinoma.

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A Study on Improvement of Maintenance System for Timber Sleepers of Ballast-less track on Railway Bridge (무도상 강철도 교량상 목침목 유지관리체계 개선방안에 관한 연구)

  • Choi, Jung-Youl;Shin, Tae-Hyoung;Kim, Sang-Jin;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.1
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    • pp.389-394
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    • 2019
  • In case of damaged timber sleepers, maintenance is carried out according to the track inspection standard. However, it is difficult to detect the extent of damage on the bridge, and maintenance is depended on inspector's judgment. In this study, we propose to improve the evaluation criterion of timber sleepers for the ballast-less tracks on serviced urban railway bridge. The timber sleepers on railway bridge was classified according to degree of damage, and damage scores were calculated for each damage grade. Also we have improved the maintenance system of the timber sleepers through the history management system of the individual timber sleepers on railway bridge. As a results, it was judged that systematic management of timber sleepers could be possible during maintenance.

A Study on Evaluation Method of Cable Tension for Railway Steel Composite Bridge (강철도 복합교량 케이블의 장력 평가기법에 관한 연구)

  • Choi, Jung-Youl;Lee, Soo-Jae;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.4
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    • pp.407-413
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    • 2022
  • In this study, the empirical formula for evaluating cable tension based on long-term measurement for about 3 years according to temperature change was proposed by proving the correlation between the expansion joint displacement of the upper road bridge and the cable tension of the lower railway bridge. The tension prediction results using the empirical formula for tension evaluation each cables proposed in this study were found to be in good agreement with the cable tension using the vibration method within 3%. Therefore, it was analyzed that it could be applied together with the vibration method that was an experimental technique, to predict and evaluate the cable tension in serviced railway steel composite bridge. As a result of applying the estimated temperature calculated by the empirical formula for expansion proposed in this study to the empirical formula, it was analyzed that a high level of reliability could be secured when compared with the vibration method. Therefore, it is judged that the empirical formula for cable tension evaluation reflecting the estimated temperature proposed in this study can be used to predict the tension of cables according to climate change in the future and establish a maintenance plan.

Engineering Properties of Sound Absorbing Foamed Concrete Using Bottom Ash Depending on Mix Factors (배합요인에 따른 바텀애시 미분말을 사용한 흡음형 기포콘크리트의 공학적 특성)

  • Kim, Jin-Man;Kang, Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.63-70
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    • 2009
  • This study is part of an ongoing research project on the development of a sound-absorbing lightweight foamed concrete manufactured by a hydro-thermal reaction between silica and calcium. As the silica source, pulverized bottom ash was used, and as several cementitious powders of ordinary portland cement, alumina cement and calcium hydroxide were used. Manufacture of foamed concrete was accomplished using the pre-foaming method to make a continuous pore system, which is the method of making the foam by using a foaming agent, then making the slurry by mixing the foam, water, and powders. The experiment factors are W/B, foam agent dilution ratio, and foam ratio, and test items are compressive strength, dry density, void ratio, and absorption rate, as evaluated by NRC. The experiment results showed that the sound absorption of lightweight foamed concrete satisfied NRC requirements for the absorbing materials in most of the experiments. It is thus concluded that foam ratio was the most dominant factor, and significantly affected all properties of lightweight foamed concrete in this study. W/B rarely affected total void ratio and continuous void ratio as well as compressive strength, and dry density and foam agent dilution ratio also had little effect onalmost all properties. The analysis of the correlation between NRC, absorption time, continuous void ratio, and absorption time showed that the interrelationship of the continuous void ratio was high.

Characterization of Streptococcus parauberis isolated from cultured Olive flounder, Paralichthys olivaceus in the Jeju Island (제주도 양식넙치 (Paralichthys olivaceus)로부터 분리한 비 용혈성 연쇄구균의 동정)

  • Kang, Chul-Young;Kang, Bong-Jo;Moon, Young-Gun;Kim, Ki-Young;Heo, Moon-Soo
    • Journal of fish pathology
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    • v.20 no.2
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    • pp.109-117
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    • 2007
  • This study was performed to identity non hemolytic streptococcus from cultured flounder (Paralichthys olivaceus) with Streptococcosis in the Jeju island. The result of BIOLOGTM test was Streptococcus uberis that simility of 0.5 and 98% identified in MicroLogTM system (Release 4.05). Carbohydrate utility pattern was dextrin, N-acetyl-D-glucosamine, arbutin, maltose, maltotriose, D-cellobiose, D-fructose, D-mannose, α-D-glucose, D-mannitol, β-methyl D-glucoside, salicin, sucrose, D-trehalose, pruvatic acid methyl ester, mono-methyl succinate, glycerol. In addition hemolysis test for S. parauberis and were S. iniae hemolysis in BAP (Blood agar plate). Antibiotic test for S. parauberis were Ampicillin, Amoxicillin and Fluoroquinolone sensitivity. Mutiplex PCR assay were detected S. pauberis (718 bp), S. iniae (870 bp) L. garviae (1,100 bp). Dectected S. parauberis (718 bp) were result of 16S rRNA sequence identified with S. parauberis (Gene bank accession number X89967). All isolated S. parauberis that with bouned by one group. The result were S. pauberis that γ-hemolytic chain form cocci and negative reaction of catalase, Multiplex PCR assay were 718 bp amplicon size.