강성(剛性) 고정(固定)이 성장중(成長中)인 가토(家兎)의 전두비골봉합(前頭鼻骨封合)에 미치는 영향(影響)에 관(關)한 연구(硏究)

김효종,김여갑,Kim, Hyo-Jong,Kim, Yeo-Gab 대한악안면성형재건외과학회 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.3

This study was aimed to clarify the histopathological changes in the experimental animal model subjcted to rigid fixation performed across the frontonasal sutrue in growing rabbits. Sixteen rabbits aged 6 weeks used. In experimental group(n=12), rigid fixation with miniplates and screws was performed across the frontonasal suture. Control group(n=4) was those with periosteal elevation only. Experimental animals were sacrificed on the 2nd, 4th, 8th, and 12th week after operation, and frontonasal suture area was excised for light microscopic and scanning electron microscopic examination. The results obtained were as follows : 1. In control groups, collagen fiber bundles ran in the midportion of bone sutrue and cambial layers were seen at bone surface. Sutural surfaces are beveled and external and internal bony projected portions were observed. 2. In experimental groups, distance of bone suture was decreased by new bone formation on the 2nd week, while increased by bone resorption at the miniplate applied area and bone formation in the adjacent bone on the 4th week. 3. In experimental groups, the original bone surface was almost resorbed and new bone formation was found on the 8th week. Regulary-run collagen fibers, smooth and dense bone surfaces were similar to the bone patterns of control groups on the 12th week. Above results suggest that bone formation is restricted where the miniplate is applied, while compensatory growth is appeared in the adjacent bont. It is considered that rigid fixation with miniplates and acrews results in a little disturbance of sutural growth of the craniofacial bone in infancy and children when applied for short duration.

체인코드 기반의 파일 무결성 검증 모델

김효종,한군희,신승수,Kim, Hyo-Jong,Han, Kun-Hee,Shin, Seung-Soo 한국융합학회 2021 한국융합학회논문지 Vol.12 No.4

Recent advances in network and hardware technologies have led to active research and multiple network technologies that fuse blockchain technologies with security. We propose a system model that analyzes technologies using existing blockchain and verifies the integrity of files using private blockchain in a limited environment. The proposed model can be written as a chain code of Hyperleisure Fabric, a private blockchain platform, and verified for integrity of files through Hyperleisure Explorer, a private blockchain integrated management platform. The system performance of the proposed model was analyzed from a developer perspective and from a user perspective. As a result of the analysis, there are compatibility problems according to the version of various modules to run the blockchain platform, and only limited elements such as chain code status and groups can be checked. 최근 네트워크 및 하드웨어 기술이 발전하여 블록체인 기술과 보안을 융합하는 연구가 활발히 진행되고 여러 네트워크 기술에 적용되고 있다. 기존의 블록체인을 활용한 기술을 분석하고 제한된 환경에서 비공개 블록체인을 활용한 파일의 무결성을 검증하는 모델을 제안한다. 제안하는 모델은 비공개 블록체인 플랫폼인 하이퍼레저 패브릭의 체인코드로 작성하고 비공개 블록체인 통합 관리 플랫폼인 하이퍼레저 익스플로러를 통해 파일의 무결성 검증을 확인할 수 있다. 제안한 모델의 성능을 개발자 관점과 사용자 관점에서 분석했다. 블록체인 플랫폼을 실행하기 위한 다양한 모듈의 버전에 따른 호환성 문제가 존재하고 체인코드 상태와 그룹 등 제한된 요소만 확인이 가능하다는 결과를 얻었다.

정변형속도와 정하중시험에서 22Cr5Ni2Mo 2상 스테인리스강의 응력부식균열 감수성

김효종(Hyo Jong Kim),이성근(Sung Keun Lee) 한국부식방식학회 1999 Corrosion Science and Technology Vol.28 No.1

N/A N/A

2상 스테인리스강 용접부의 저온충격인성과 내응력 부식성에 관한 연구

김효종(Hyo-Jong Kim),이성근(Sung-Keun Lee) 한국해양공학회 1995 韓國海洋工學會誌 Vol.9 No.1

The characteristics of low temperature impact toughness and stress corrosion resistance at boiling MgCl₂ solution of GTA and SMA weld of duplex stainless steels have been investigated. The impact toughness was highest at the GTAW weld metal and lowest at the SMAW weld, which was almost the same as that of the SMAW heat-affected zone.<br/> This was attributable to influence of austenite-ferrite phase balance, and the degree and nature of precipitation that occured during welding. The SCC resistance of the weldments decreased with decreasing strain rate. And the SCC resistance of the weldments was slightly higher than that of the base metal, whereas no difference in the SCC resistance was found between two different weldments.

강성 고정이 성장중인 가토 전두비골규합에 미치는 영향에 관한 연구

김효종(Hyo Jong Kim),김여갑(Yeo Gab Kim) 대한악안면성형재건외과학회 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.3

This study was aimed to clarify the histopathological changes in the experimental animal model subjcted to rigid fixation performed across the frontonasal sutrue in growing rabbits. Sixteen rabbits aged 6 weeks used. In experimental group (n =12), rigid fixation with miniplates and screws was performed across the frontonasal suture. Control group (n=4) was those with periosteal elevation only, Experimental animals were sacrificed on the 2nd, 4th, 8th, and 12th week after operation, and frontonasal suture area was excised for light microscopic and scanning electron microscopic examination. The results obtained were as follows 1. In control groups, collagen fiber bundles ran in the midportion of bone sutrue and cambial layers were seen at bone surface. Sutural surfaces are beveled and external and internal bony projected portions were observed. 2.In experimental groups, distance of bone suture was decreased by new bone formation on the 2nd week, while increased by bone resorption at the miniplate applied area and bone formation in the adjacent bone on the 4th week 3. In experimental groups, the original bone surface was almost resorbed and new bone formation was found on the 8th week Regulary-run collagen fibers, smooth and dense bone surfaces were similar to the bone patterns of control groups on the 12th week Above results suggest that bone formation is restricted where the miniplate is applied, while compensatory growth is appeared in the adjacent bont, It is considered that rigid fixation with miniplates and acrews results in a little disturbance of sutural growth of the craniofacial bone in infancy and children when applied for short duration.

적외선 열화상 기술의 최신 연구 동향과 발전 현황 (Recent Advancement and Development on Infrared thermography Technique)

김효종(Hyo-Jong Kim),김정국(Jeongguk Kim),김남포(Nam-po Kim) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.5

All objects emit infrared above absolute temperature 0K. Infrared thermography is one of the nondestructive testing technologies to measure the temperature of the object. Infrared thermography shows infrared image which in a longer wavelength than visible light. Infrared technology can be employed regardless of the type or state of the objects. Thus, infrared thermography technique has been used in a wide variety of manufacturing processes in areas such as mechanical, electrical, chemical and medical applications. The advancement of using infrared technology has been increasing. In this paper, the principle of lock-in infrared thermography and its applications were investigated, and the direction of future development was discussed.

The Dismantling and Disposal Strategy of a Biological Shield for Minimization of Radioactive Concrete Waste During Decommissioning of a Nuclear Power Plant

Cheol-Seung Cheon,Chang-Lak Kim 한국방사성폐기물학회 2017 방사성폐기물학회지 Vol.15 No.4

2017년 6월에 영구정지 된 고리 1호기의 해체는 한국의 상업 원전에 대한 첫 해체 사례가 될 것이다. 해체 과정 중에 발생하 는 폐기물에 대한 처분은 전체 해체 비용의 많은 부분을 차지한다. 따라서 방사화 및 오염된 콘크리트 구조물은 적절한 해체 전략을 수립하여 경제적이고 안전하게 해체되어야 한다. 본 논문에서는 생물학적 차폐체에 대한 최적화된 해체 및 처분 시 나리오를 연구하였다. 해체사례, 폐기물 처분 규정 및 처리 기술을 분석하였다. 그리고 생물학적 차폐체 제거 과정의 폐기물 발생량을 최소화하기 위해서, 최적 해체 시나리오를 제시하였고 폐기물 처분 방안을 도출하였다. The decommissioning of Kori unit 1, which was permanently shut down in June of 2017, will be the first instance of the dismantling of a commercial nuclear power plant in Korea. The disposal of waste during the dismantling process accounts for a large part of the total decommissioning cost. Therefore, structures consisting of activated and contaminated concrete must be economically and safely dismantled by establishing a proper dismantling strategy. This study focuses on optimized dismantling and disposal scenarios pertaining to a biological shield. Several dismantling cases, regulations and technologies related to waste treatment as these practices pertain to nuclear power plants are analyzed. To minimize the amount of waste from the biological shield dismantling process, an optimized dismantling scenario is presented and disposal alternatives for dismantled concrete waste are proposed.

심한 성장장애를 보인 Crohn 대장염 1 예

김효종(Hyo Jong Kim),김배영(Bai Young Kim),김병호(Byung Ho Kim),이정일(Joung Il Lee),장영운(Young Woon Chang),장린(Rin Chang),이기형(Kee Hyung Lee),전정열(Jung Youl Chun) 대한내과학회 1991 대한내과학회지 Vol.40 No.2

Growth retardation and delayed sexual maturation occur in 15-30% of adolescents afflicted with Crohn`s disease and social complication of these immaturity are often more debilitating than the gastrointestinal manifestation. The etiology of this abnormal growth had been unknown, and various forms of therapy including surgery had yielded disappointing results. Recently, however, chronic caloric insufficiency has been documented in several reports and nutritional restitution using enteral and parenteral routes reverses growth retardation in these patients, and these nutritional effects on growth may be mediated by somatomedin-C. We recently experienced a case of Crohn`s colitis with growth retardation and delayed sexual maturation in adolescent who underwent surgical resection, so we couldn't confirm the nutritional effect on growth but the patient had no endocrine dysfunction and no history of corticosteroid therapy which had been incriminated as possible causes of growth retardation. We report a case of Crohn`s colitis with growth retardation.

펄스 변조 및 전원 스위칭 방법을 혼용한 X-대역 50 W Pulsed SSPA 설계 및 제작

김효종(Hyo-Jong Kim),윤명한(Myoung-Han Yoon),장필식(Pil-Sik Chang),김완식(Wan-Sik Kim),이종욱(Jong-Wook Lee) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.4

본 논문에서는 레이더 시스템에 적용이 가능한 50 W 출력을 가지는 X-대역 pulsed SSPA(Solid State Power Amplifier)를 설계 및 제작하였다. SSPA를 펄스 모드로 동작시키는 방법으로 펄스 변조 방법과 전원 스위칭 방법을 혼용한 방법을 제안하였다. SSPA는 구동 증폭기, 고출력 증폭기, 펄스 변조기로 구성되며, 충분한 이득과 출력 크기를 얻기 위해 25 W GaAs FET 4개를 병렬 구조로 구성하였다. 측정 결과 1.12 ㎓ 대역폭에서 출력 50 W, 이득 44.2 ㏈의 성능을 가졌다. 또한, pulse droop은 1 ㏈ 이하로 설계 목표를 만족하였으며, 12.45 ㎱ 이하의 상승/하강 시간을 가졌다. 제작된 X-대역 pulsed SSPA 크기는 150×105×30 ㎣로 매우 작은 크기를 가졌다. In this paper, a X-band 50 W pulsed solid state power amplifier(SSPA) is designed and fabricated for radar systems. The SSPA consists of a driver amplifier, a high power amplifier, and a pulse modulator. The high power stage em-ployes four 25 W GaAs FET to deliver 50 W at X-band. To meet the stringent target specification for the SSPA, we used a new hybrid pulse switching method, which combine the advantage of pulse modulation and bias switching method. The fabricated SSPA shows a power gain of 44.2 ㏈, an output power of 50 W over a 1.12 ㎓ bandwidth. Also, pulse droop < 1 ㏈ meet the design goals and a rise/fall time is less than 12.45 ㎱. Fabricated X-band pulsed SSPA size is compact with overall size of 150×105×30 ㎣.

디바이스의 DDoS 공격 여부 판단 및 대응 시스템 설계

김효종(Hyo-jong Kim),최수영(Su-young Choi),김민성(Min-sung Kim),신승수(Seung-soo Shin) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.1

2015년부터 IoT 프로토콜을 사용한 공격이 지속적으로 보고되고 있다. 다양한 IoT 프로토콜 중 공격자는 SSDP(Simple Service Discovery Protocol)를 사용하여 DDoS 공격을 시도하고 있으며, 사이버 대피소 통계로 한국은 약 100만 개의 개방형 SSDP 서버를 보유하고 있다. 인터넷에 연결된 취약한 SSDP 서버는 50Gb 이상의 트래픽을 생성할 수 있으며 공격 위험은 점진적으로 증가한다. 최근까지도 분산 서비스 거부 공격과 분산 반사 서비스 거부 공격이 보안 문제로 대두되고 있다. 따라서 본 연구의 목적은 기존 SSDP 프로토콜의 요청 패킷을 분석하여 증폭 공격을 식별하고 증폭 공격이 의심되는 경우 대응을 회피하여 다량의 응답 패킷 발생으로 인한 네트워크 부하를 방지하는 것이다. Since 2015, attacks using the IoT protocol have been continuously reported. Among various IoT protocols, attackers attempt DDoS attacks using SSDP(Simple Service Discovery Protocol), and as statistics of cyber shelters, Korea has about 1 million open SSDP servers. Vulnerable SSDP servers connected to the Internet can generate more than 50Gb of traffic and the risk of attack increases gradually. Until recently, distributed denial of service attacks and distributed reflective denial of service attacks have been a security issue. Accordingly, the purpose of this study is to analyze the request packet of the existing SSDP protocol to identify an amplification attack and to avoid a response when an amplification attack is suspected, thereby preventing network load due to the occurrence of a large number of response packets due to the role of traffic reflection amplification.