• Archives of Reconstructive Microsurgery
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• v.3 no.1
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• pp.45-53
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• 1994

Suture microvascular anastomosis is time-consuming and tedious and demands long and continuous training. Techinique of anastomosis of microvessel was presented interrupted suture and continuous suture. Recently the unilink instrument system is created as a fast and simple method to achieve high patency rates without long and continuous training in the anastomosis of small vessels. The author experimentally studied the femoral artery of 20 mice(0.5-1.0mm, av. 0.7mm), the femoral vein of 20 mice(0.8-1.6mm, av. 1.2mm) after anastomosis with interrupted suture in 20 cases and continuous sutre in 20 cases. For the unilink apparatus we used the carotid arteries of 15 cases in 14 rabbits(1.0-1.6mm, av. 1.3mm) and facial veins of 12 cases in 14 rabbits(0.9mm-2.2mm, av. 1.5mm). A total of 27 arterial and venous anastomoses were performed. We examined the postoperative patency at immediate, 2 weeks, and 8 weeks. The results were as followings, 1. In the arterial anastomosis the rate of patency was 90%(18/20) in interrupted suture, 90%(18/20) in continuous suture and 93%(13/15) in unilink apparatus. In the venous anastomosis the rate of patency was 90%(18/20) in interrupted suture, 80%(16/20) in continuous suture and 100%(9/9) in unilink apparatus. 2. The mean time for completion of the arterial anastomosis were 12.2 minutes in interrupted suture group, 10.3 minutes in continouous suture group and 8.5 minutes in unillnk apparatus group. The mean time for completion of the venous anastomosis were 13.6 minutes in interrupted suture group, 11.0 minutes in continuous suture group and 6.2 minutes in unilink apparatus group. 3. At the histological examination of suture group, hyperplastic reaction of middle layer and subintimal hyperplasia were observed. In unilink apparatus group, the endothelium layer was continued and the thickness of vessel wall was decreased due to moderate atrophy of the media and mild degree of nonspecific chronic inflammation were seen around the unilink apparatus. 4. No significants was noticied in foreign body reaction among the interrupted, continuous and unilink apparatus group. 5. A case of the arterial anastomosis was released with acting out at 15 minutes after operation. 6. The important factors in the technical problems were accurate apposition of the cut vessel edges in suture group and the proper selection of the ring size and optimal fitting between two rings in unilink apparatus group. Even though the outer diamater of vessel in suture group was different from that in unilink apparatus group the unilink method provides a very safe, fast, and simple way to perform microvascular anastomoses especially in anastomosis of vein. But howerver suture was needed in vessels below 1 mm outer diamater. In that situation continuous suture was benefit than the interrupted suture in operation time.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.83-85
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• 2008

현행 지상파 DMB(Digital Multimedia Broadcasting)에서는 최대 CIF급 해상도의 동영상을 384 Kbps 정도의 비트율로 압축하여 비디오 CD급의 화질을 제공한다. 따라서 큰 화면을 통해 DMB 방송을 시청할 경우 해상도 부족 등으로 인한 화질 열화를 느낄 수 있다. 이와 같은 문제를 해결하기 위한 방안으로 계층적으로 부호화된 비트스트림을 서로 다른 채널로 전송하는 고품질 AT-DMB 시스템이 연구되고 있다. 더불어, 계층변조 기술을 이용하여 추가적인 전송대역폭을 확보하고, 계층적 비디오 부호화 기술을 이용하여 고품질 이동 멀티미디어 방송을 제공하는 고품질 T-DMB 방식이 개발되고 있다. 이와 같은 AT-DMB 방식으로 사용자에게 안정된 고품질 비디오 서비스를 제공하기 위해서는 계층적 비디오 부호화를 고려한 효율적인 AV다중화 및 동기화 구조에 대한 연구가 필수적으로 요구 된다. 본 논문에서는, 이와 같은 고품질 AT-DMB 시스템을 위해서 각 계층 ES(Elementary stream)을 MPEG-4 over MPEG-2 시스템과 Eureka-147 DAB 시스템을 통해 서로 다른 채널로 전송한다. 계층별 전송으로 인한 시간 지연에 대처하여 수신입력부에서는 각각의 계층으로 전송된 ES들이 동기화 되어 복호화 되도록 SVC의 계층적 비트스트림 구조와 적응적으로 동작되는 다중화 시스템구조를 제작하였다.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.655-660
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• 2005

The number of broadcasting channels and contents are increasing with the arrival of digital broadcast and various broadcasting medium. However, there is a limit on searching of the program by using conventional program guide. Therefore, personalized broadcasting service to provide the environment, that user is able to consume his/her customized broadcasting contents at anytime, is standardized by TV-Anytime Forum. Especially. the structure of data broadcasting contents have different from that of AV contents. Therefore, it is necessary to new structure of the metadata for personalized data broadcasting service and new mechanism for data flow of broadcasting system. In this paper, we introduce a method for personalized data broadcasting service using TV-Anytime metadata.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.287-290
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• 2010

최근 기기간의 접속에 적합한 근거리 무선 접속기술의 요구가 증대됨에 따라, 그 요구에 대응하는 무선통신기술의 하나로 UWB(Ultra Wide Band)가 주목을 받고 있다. 특히, TV와 캠코더, 카메라 등의 AV기기 상호 간의 무선접속을 포함하여 PC나 휴대정보단말(PDA) 등이 네트워크에 무선으로 접속하는데 UWB 기술은 주요한 역할을 담당할 것으로 예상된다. 최근 서비스가 진행되고 있는 HDTV를 비롯하여 향후 UHDTV(Ultra-HDTV) 등의 방송시스템이 본격화되면 HD급 이상의 캠코더는 고해상도에 따른 대용량 데이터를 저장하고 AV기기 간의 데이터 전송을 위해 고속 무선 데이터 전송이 필수적이다. 또한 이와 같은 고속 무선데이터 전송을 위해서는 보다 안정된 송수신 기술이 절대적으로 필요하다. 이를 위하여 본 논문에서는 차세대 UWB의 설계 제약조건 중 하나인 저전력 송신환경에서 수신 신뢰도의 향상을 이루기 위해 LDPC code를 오류정정부호로 고려하고, 제한된 반복복호 횟수를 가지고 개선된 성능을 얻기 위해 새로운 복호 알고리즘을 제안하였다. 또한, 제안한 복호 알고리즘에 대해 모의실험을 통하여 성능을 검증함으로써 차세대 UWB 송수신 기술로서의 유용성과 적용 가능성을 제시하였다.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.187-200
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• 2011

We present the design and implementation of a novel anti-malware system called SplitScreen. SplitScreen performs an additional screening step prior to the signature matching phase found in existing approaches. The screening step filters out most non-infected files (90%) and also identifiesmalware signatures that are not of interest (99%). The screening step significantly improves end-to-end performance because safe files are quickly identified and are not processed further, and malware files can subsequently be scanned using only the signatures that are necessary. Our approach naturally leads to a network-based anti-malware solution in which clients only receive signatures they needed, not every malware signature ever created as with current approaches. We have implemented SplitScreen as an extension to ClamAV, the most popular open source anti-malware software. For the current number of signatures, our implementation is $2{\times}$ faster and requires $2{\times}$ less memory than the original ClamAV. These gaps widen as the number of signatures grows.

• International journal of advanced smart convergence
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• v.6 no.2
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• pp.1-8
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• 2017

Recently, the development of the information communication industry has made many changes in the industrial acoustic industry. Especially, it has a great influence on the change of system and equipment of acoustic system. Analog equipment is changing to digital equipment, and integrated control equipment makes it easier to operate and manage the sound system. However, the integrated control system currently on the market is only controllable for some devices. In this paper, we propose a new AoIP - based system configuration method, which enables the operation status monitoring, unmanned operation and self - diagnosis of equipment. As a result of the study, it is confirmed that the proposed system can be operated, monitored, and self - diagnosed at remote sites. It is expected that an AoIP- based sound system will be the industry standard in the future.

• KIPE Magazine
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• v.9 no.3
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• pp.18-22
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• 2004

PC용 마이크로프로세서는 Intel사의 아키텍처로 거의 표준화되어 있지만, 임베디드 마이크로프로세서에 눈을 돌린다면 마치 춘추전국시대의 양상을 뛰고 있다 국외에서 임베디드 마이크로프로세서로써 주목을 받는 것들 중에 하나인 Renesas Technology사(2003년, 히타치와 미쯔비시와의 합작회사)의 SuperH(SH) 계열을 소개하고자 한다. 현재 국내에서는 SuperH RISC CPU를 사용하는 교육기관. 연구소, 그리고 업체는 소수에 그치고 있지만, 한국을 제외한 국외에서는 TI사의 TMS시리즈와 같이 전력전자분야뿐만 아니라 로봇, 모바일 홈네트워크, AV기기, CIS(Car Information System) 등의 분야에도 폭 넓게 응용되고 있다. [1-4] 저자는 본 특집을 통해 SuperH시리즈에 대한 구조와 특징을 소개함으로써 국내에서도 이를 이용한 연구활동이나 제품개발에 커다란 도움이 되었으면 한다.(중략)

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1227-1230
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• 1998

Phase control methods are used to expand the sound image in general AV system. However, these methods are effective only to the signal under 1kHz, and the listener must be located in front center of the speaker system. In this paper, we realize the realtime processing system in which phase shifting method is dominant at low frequency and precedence effect is dominant at high frequency. Two sound cards are used to process the audio signal in realtime with 16 bits stereo channel of 44.1 kHz sampling frequency. And the analog circuit is designed to process the phase shifting. In experiments the usefulness of the proposed stereo system is confirmed.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.353-364
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• 2011

RAM(Reliability, Availability and Maintainability) is one of the important indicators to show the performance of weapon systems. For analyzing RAM characteristics, RAM simulation is useful and powerful as mathematical techniques. However, it is necessary to build the simulation model to express about the operation environment of weapon systems, and obtain detail input data for reliability and maintainability about the system to get accurate results by RAM simulation. In this paper, we propose a procedure to analyze RAM of the searching system consisting in weapon systems by RAM simulation and we estimate searching system availability by a commercial simulation program, AvSim.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.197-217
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• 2022

As automated vehicle(AV) accidents continue to occur, the importance of safety verification to ensure the safety and reliability of automated driving system(ADS) is being emphasized. In order to encure safety and reliability, it is necessary to define an operational design domain(ODD) of the ADS and verify the safety of the ADS while evaluating its ability to respond in situations outside of the ODD. To this, international associations such as SAE, BSI, NHTSA, ISO, etc. stipulate ODD standards. However, in Korea, there is no standard for the ODD, so automated vehicles's ODD expression method and safety verification and evaluation are not properly conducted. Therefore, this study analyzed overseas ODD standards and selected suitable ODD for safety verification and evaluation, and presented evaluation elements for ADS safety verification and evaluation. In particular, evaluation elements were selected by analyzing the evaluation environment of the automated driving experimental city (K-City) that supports the development of ADS technology.