• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.133-137
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• 2006

In general, a measuring instrument of sound noise use only one wired channel by one sensor. Therefor the measuring instrument use wired cables as the number of channels are provided by instrument. In a point of observed target it needs data from multiple sensors and In case of measured point is a large numbers the environment of constitution would be complicated because that is in need of channel and cable. So we need the method that can improve the existing transmission channel and cable environment even the measured point is increased. If we use the Code Division Multiple Access(CDMA) we transmit a large numbers of sensor data by using a common transmission channel. We present the method that transmits data of multiple sensor to wireless by using CDMA. This method can simplify the measurement environment dramatically when collecting data by using multiple sensor. We expect this study to contribute the part of multiple access technology and relation technologies on the measuring environment.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.5-8
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• 2001

Wideband code division multiple access (WCDMA) is the most widely adopted third generation air interface. The physical layer of the air interrace is the main discussion topic during standardization processes. This paper aims to investigate the performance of uplink WCDMA over many conceivable transmission scenarios in realistic operating conditions. The focus of the study is placed on the performance under frequency selective fading channel conditions with multiple access interference (MAI) in mixed services environments. For the investigation, a simulator has been developed and it encompasses a variety of WCDMA air interface features. The results show that the performance is greatly affected by MAI and is further aggravated with the presence of frequency selective fading, thereby necessitating a suitable compensation measure.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.53-59
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• 2000

In this paper, considering configuration of the earth and environment of country, it is classified a radio propagation environment Multipath propagation measuring system based on PN code correlation detection method is built to study a wave propagation characteristics of 1.95GHz. Considering the characteristic artificial structure of country, Cihwa plant superintendent area has been selected for basic and accurate measurement a radio propagation characteristic. The experiments are carried out with respect to the RMS delay Spread and the received power in the two kind of geographical areas, LOS (Line of Sight) and N-LOS (Non Line of Sight). The measurement result of that received power of LOS area is -1.6∼-28.8dBm, RMS delay spread is 0.023㎲∼0.22㎲ and received power of N-LOS area is 16∼36.5dBm and RMS delay spread is 0.068∼0.37㎲.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.581-584
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• 2002

The graylevel image scanning system realization and design using CIS(Contact Image Scanning)be amenable to recognize a papers, OMR and OCR sheet is proposed. The design technique is used CIS scanning sensor in fixing step motor and is optimized with DSP processor for image processing., and transfer input image data par line in feeding a step unit to PC on the USB interfacer. This system is portable and A4 size scanning and keeps image scan processing speed 300mm/sec The recognition percentage has 98% on the OCR and bar codes.

• Convergence Security Journal
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• v.8 no.4
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• pp.183-189
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• 2008

E-mail's role has been increased due to its merit which is sending demanded information in real-time anywhere, anytime. However, Today's E-mail security threats have being changed intelligently to attack against the specific agency. The threat is a limit to respond. Therefore precise definition and development of security technology is needed to analyze changing environment and technologies of e-mail so that remove fundamental security threat. we proposed Next Generation E-mail System Security Structure and the Next Generation fusion System using authentication As a result, in this study, we development of Next Generation E-mail System Security Structure. This system can protect E-mail user from social engineering hacking technique, spam, virus, malicious code and fabrication.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.133-133
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• 2001

무선 근거리 지역망(Wireless LAN;WLAN) 환경에서 다중 채널을 이용하여 실시간 서비스를 제공하기 위한 매체 접근제어 계층에서의 채널의 사용 구간 할당 방법을 제안하고, 컴퓨터 모의 실험을 통하여 제한된 방식의 실시간 서비스 지원 성능과 채널의 사용 효율을 분석한다. 제안한 채널 사용 구간 할당 방안은 개선된 매체 접근 제어 프로토콜 RICH-DP (Receiver-Initiated Channel-Hopping with Dual Polling)를 바탕으로 한다. 무선 환경에서 RTS-CTS를 사용하는 프로토콜은 SRMA, MACA, MACAW, IEEE 802.11, FAMA 등이 있다. 최근에 단일 채널을 환경에서 RICH(Receiver Initiated Channel-Mopping) 프로토콜이 제안되었다. RICH는 충돌 회피를 위해서 경쟁 구간에서 충돌 감지(carrier sensing)을 사용한다. RICH는 제한된 어플케이션에 국한되는 단절이 있다. 반면에 RICH-DP는 다중 채널 환경에서 충돌 감지와 특별한 코드(spreading code) 할당 없이 일반화된 충돌 회피를 제공한다. 실시간 서비스를 이용하자 차는 단말들로 하여금 RICH-DP를 사용하여 서비스를 제공할 때, 대역폭에 대한 정보를 AP(Access Point)로 전송토록 함으로써 비경쟁 구간에서 뿐 아니라, 경쟁구간에서도 높은 채널 효율이 얻어질 수 있도록 하고 있다. 제한된 방안의 성능 평가를 위한 모의 실험은 OPNET를 이용하여 실시간 서비스 데이터를 7개의 상태 천이를 갖는 VBR 소스로 모델링하고 비동기 트래픽들은 Poisson 소스로 모델링하여 실시간 서비스 단발들의 이용 대역폭과 채널 처리율과 시스템 지연시간을 성능 평가 인자로 하여 수행하였다. 논문에서 제한된 방법을 적용한 개선된 RICH-DP을 모의 실험을 통하여 분석한 결과 기존의 제한된 RICH-DP는 실시간 서비스에 대한 처리율이 낮아지며 서비스 시간이 보장되지 못했다. 따라서 실시간 서비스에 대한 새로운 제안된 기법을 제안하고 성능 평가한 결과 기존의 RICH-DP보다 성능이 향상됨을 확인 할 수 있었다.

• Journal of IKEEE
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• v.19 no.4
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• pp.617-624
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• 2015

In this paper, an adult authentication system based on authentication certificate was designed and implemented using smartphone and near-field communication. It has three advantages. First, it achieves easy, convenient, and fast authentication by using smartphone and near-field communication. Second, it achieves extremely high security and reliability by exploiting authentication certificate. Third, it achieves extremely low risk of personal information leakage by generating and sending only virtual identification code. Finally, it has a proper legal basis by Digital Signature Act. It consists of adult authentication module, near-field communication control module, policy server module, and database server module. A prototype of the proposed system was designed and implemented, and it was verified to have correct operation.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.331-337
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• 2005

'Supplement 23:DICOM SR' announced on April 2000 made possible co-relations between the clinical reports and human body parts by standardizing the exchange of clinical information. DICOM SR uses its own coding schemes and values to represent information, which convey hierarchically structured content items. This paper analyzes radiology reports produced in HIS(Hospital Information System) and categorizes content structures into three parts such as, finding, conclusion, and recommendation, and implements a system which can be used by clinicians. Digital X-ray images and their reports have been managed separately. Since the report made by DICOM SR can refer to images, the integrated information of reports and images is possible.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.2
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• pp.83-91
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• 2007

The purpose of this paper is developing a PML server which is capable of saving and managing effectively the information of vehicles using RFID technology in the logistical and distributive environment. The PML server logs and manages the real-time static and dynamic information about the vehicles in EPC code format which is represented by XML schema and transmitted by the RFID reader to the server. It receives information from SAVANT the RFID middleware and transmits the data to the traffic information management application The main system we developed consists of the EPC data registry, query processor, data converter, vehicle product and instance data storage, system management tool and application API parts.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.565-568
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• 2005

RFID system allows contactless identification of objects, where small tags are attached to objects and information of objects are transferred using radio frequency. In recent years, industries have incorporated several identification systems to its production processes, which allow collecting automatically information about goods. In order to communicate with a single tag out of a group of tags, the target tag has to be identified. Therefore the read has to attempt to obtain the unique identification code of each tag within its read range. This paper presents performance results of QT and QT-sl protocols, which are tag identification protocols incorporating memoryless property. The memoryless property is that the current response of each tag only depends on the current query of the reader but not on the past history of the reader's queries.