사이버공격 역추적기술 동향

김정태,한민호,이종훈,김종현,김익균,Kim, J.T.,Han, M.H.,Lee, J.H.,Kim, J.H.,Kim, I.K. 한국전자통신연구원 2014 전자통신동향분석 Vol.29 No.1

본 논문은 인터넷을 통해 급격히 확산되고 있는 해킹, 바이러스 및 DDoS(Distributed Denial-of-Service) 공격과 같은 사이버 보안 공격(Cyber Security Attack) 등이 발생하였을 경우 각 공격에 효과적으로 대비하기 위한 방향 및 그 방법을 제시하기 위해서 실제적인 공격 근원지 정보 역추적을 위하여 관련 추적 기술의 의미, 세부기술 분류, 관련 연구 및 동향 등을 통하여 기존 역추적기술의 제약사항을 극복하고 현재 또는 차세대 인터넷에서 적용가능한 역추적기술에 대한 요구사항 및 향후 전망을 기술하였다.

고분자-계면활성제 혼합물에 의한 마찰저항 감소연구

김정태,김철암,최형진,김종보,윤형기,박성룡,Kim, Jeong-Tae,Kim, Cheol-Am,Choe, Hyeong-Jin,Kim, Jong-Bo,Yun, Hyeong-Gi,Park, Seong-Ryong 한국재료학회 1998 한국재료학회지 Vol.8 No.2

본 연구에서는 회전 원판 장치에 고분자-계면활성제의 혼합체를 첨가제로 사용하여 난류 유동장에서의 마찰저항 감소효과에 대해서 조사 연구하였다. 세가지의 분자량이 다른 PAA를 마찰저항 감소효과에 영향을 줄 수 있는 여러 인자들에 대헤서 살펴 보았다. 특히 이 연구에서는 이온성 고분자와 계면활성제의복합체가 마찰저항 감소현상에 어떠한 영향을 미치는 지에 대해서 연구하였다. 계면활성제와 고분자첨가제 사이의 형태학적 차이점에 특별한 관심을 가지고 실험을 하였으며 이온성 고분자의 pH에 대한 영향에 대해서도 조사하였다. 고분자와 계면활성제간의 복합체는 거대한 전해질과 같은 거동을 보이며 계면활성제가 고분자의 형태를 변화시켜 고분자의 크기를 확대시킨다. 따라서 이러한 복합체는 단일 고분자계와 비교해서 수력학적부피, 관성반경, 점도등의 값이 크게 나타나며 이렇게 팽창된 고분자는 난류 유동장에서의 마찰저항 감소효율을 증가시킨다. Drag reduction produced by dilute solution of water soluble ionic polymer-surfactant complex under turbulent flow in a rotating disk apparatus(RDA) was investigated in this study. Three different molecular weights of polyacrylic acid(PAA) were adopted as drag reducing additives, and distilled water was used as a solvent. Experiments were undertaken to observe the dependence of drag reduction on various factors such as polymer molecular weight, molecular expansions and flexibility, rotating speed of the disk and polymer concentration. Specific considerations were put on conformational difference between surfactant and polymer, and effect of pH on ionic polymer possessing various molecular conformation through pH. The complex of ionic polymer and surfactant(Sodium Dodecyl Sulfate) behaves like a large polyelectrolyte. Surfactant changes the polymer conformation and then increases the dimension of the polymer. The radius of gyration, hydrodynamic volume and relative viscosity of the polymer-surfactant system are observed to be greater than those of polymer itself. Such surfactant-polymer complex has enhanced drag reduction properties.

횡복직근 유리피판을 이용한 유방재건술에서의 즉시 유두재건

김정태,김창연,차지훈,황원중,Kim, Jeong Tae,Kim, Chang Yeon,Cha, Ji Hun,Hwang, Weon Jung 대한성형외과학회 2005 Archives of Plastic Surgery Vol.32 No.1

Immediate breast reconstruction in breast cancer patients is universalized and now with a wide variety of methods to choose from, we can select a breast reconstruction method according to the patient's condition. Among these methods, immediate breast reconstruction with TRAM free flap is the most commonly used. Nipple reconstruction is usually performed as a secondary procedure, reconstructed. Nipple is reconstructed with contralateral nipple composite graft or with local flap. Areola is reconstructed with skin graft and tattooing. Therefore, to reconstruct complete breast, two or more staged operations are needed and are troublesome to both the surgeon and the patient. If we could reconstruct breast mound and nipple at same time, we would reduce the operative stages and heighten the patient's satisfaction. The author performed delayed or immediate breast reconstruction with TRAM free flap and nipple reconstruction at the same time. If the TRAM flap was to situate in the whole of the breast or at the center of the breast mound, nipple was reconstructed with a local flap from the TRAM flap. If the TRAM flap was not situated in center of breast mound, nipple was reconstructed with a local flap from remnant breast skin. Immediate nipple reconstructions in breast reconstruction consisted total of 22 cases. Among these, delayed breast reconstruction were 5 cases and immediate breast reconstruction were 17 cases. According to patient's condition and mastectomy method, nipple reconstruction method was selected; nipple reconstruction with contralateral nipple composite graft(3 cases); nipple reconstruction with remnant breast skin(6 cases); nipple reconstruction from flap margin(10 cases); nipple reconstruction with prefabricated nipple on flap(3 cases). Malposition of the reconstructed nipple was the most common and serious complication(6 cases). The other complications were atrophy of the nipple(1 case), and necrosis(1 case). Reconstruction of the breast and nipple at the same time can reduce the need of a secondary operation and use remnant skin or redundant flap tissue maximally. On the other hand, it must be considered that position and shape of nipple could be deformed, because the nipple reconstruction is performed before the shape of reconstructed breast settles completely. Prudent attention is needed, because the danger of complication is higher than delayed nipple reconstruction.

6자유도 조작장치의 설계와 기구학적 특성에 관한 연구

김정태,김문생,Kim, Jeoung-Tae,Kim, Moon-saeng 대한기계학회 1998 大韓機械學會論文集A Vol.22 No.2

The Six Degree-of-Freedom manipulators are generally operated by linear actuators which are hydraulic cylinder, pneumatic cylinder, ball-screw. But these actuators are not adequate to have a wide work-space, and furthermore some of them have a self-locking property. Therfore, we have designed a new manipulator which fully overcomes these demerits. The new manipulating system consists of 6 DC-motors to generate operation forces and 6 position transducers to feedback displacement signals. This paper presents an overview of the design and characteristics of 6 Degree-of-Freedom force feedback manipulators for vitual reality implementation. we can operate Six Degree-of-Freedom manipulator with six motors and six potentiometers.

말초 이골증을 동반한 Joubert Syndrome 1례

김정태,김선준,주찬웅,조수철,이대열,Kim, Jung Tae,Kim, Sun Jun,Joo, Chan-Uhng,Cho, Soo Chul,Lee, Dae-Youl The Korean Pediatric Society 2007 Clinical and Experimental Pediatrics (CEP) Vol.50 No.3

본 증례 보고는 작은 키와 단지증을 가진 전형적인 Joubert Syndrome 환아의 10년간 장기 추적 관찰한 결과이다. 환아는 영아기 초기부터 저호흡이 동반된 빈호흡, 율동성 안구 운동, 근긴장저하를 보였다. 생후 5개월에 Joubert Syndrome의 임상 증상과 전형적 MRI 소견을 보여 진단되었다. 비정상 호흡과 안구 운동은 4세경에 사라졌다. 두위는 정상 범위를 유지하였으나 키와 몸무게는 뚜렷히 정체되었다. 단순 방사선 소견 상 뇌압 상승 소견이 있는 커진 두개골과 안면골의 저형성, 손과 발의 비정상적 연골 형성을 보였다. 본 증례는 말초 이골증이 있는 Joubert Syndrome의 첫번째 보고이다. This report describes the long-term follow-up of a 10-year-old female patient with Joubert syndrome with short stature and brachydactyly. She presented with hyperpnea alternated with hypopnea, uncontrolled jerking eye movements, and hypotonia during early infancy. She was diagnosed with Joubert syndrome based on clinical symptoms and typical MRI findings at 5 months of age. Abnormal ventilation and eye movements disappeared at around 4 years of age. Head circumference kept within normal range for her age, but her height and weight growth were markedly retarded. Simple X-ray showed an enlarged skull with increased digital markings, hypoplasia of facial bones, and abnormal enchondral bone formations in hands and feet. This article is the first report of Joubert syndrome with peripheral dysostosis.

반도체 레이저의 광 주입을 이용한 혼동 통신망의 암호화 기법 분석

김정태,Kim Jung-Tae 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.4

We theoretically studied synchronization of chaotic oscillation in semiconductor lasers with chaotic light injection feed-back induced chaotic light generated from a master semiconductor laser was injected into a solitary slave semiconductor laser. The slave laser subsequently exhibited synchronized chaotic output for a wide parameter range with strong injection and frequency detuning within the injection locking scheme. We also analytically examined chaos synchronization based on a linear stability analysis from the view point of synchronization based on a linear stability analysis from the view point of modulation response of injection locked semiconductor lasers to chaotic light signal.

Analyses of a Signal Traffic for Authentication in Mobile Sensor Network

김정태,Kim Jung-Tae The Korea Institute of Information and Commucation 2005 한국정보통신학회논문지 Vol.9 No.7

In this paper, we analyses of a traffic for authentication signaling in third generation mobile sensor network. In universal mobile telecommunication system, authentication functions are utilized to identify and authentication a mobile station and validate the service request network services. The authenticating parties are the authentication the serving general packet radio service support node access the authentication center to obtain the authentication with the mobile station. In this paper, we propose that the automatic cost-effective solution size of the authentication vector array.

Neurofibromatosis Type 2와 무관하게 발생된 척추 경막내 다발성 신경초종 - 증 례 보 고 -

김정태,성정남,박봉진,조맹기,김영준,Kim, Jung Tae,Sung, Jung Nam,Park, Bong Jin,Cho, Maeng Ki,Kim, Young Joon 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.4

Most extracranial schwannomas are solitary, but neurofibromas are frequently associated with other manietations of neurofibromatosis. Schwannomas that occur within the context of neurofibromatosis tend to be multiple, but multiple schwannomas without manifestation of neurofibromatosis type 2 are very rare. The authors report a very rare case of multiple spinal intradural schwannomas in the absence of neurofibromatosis Type 2 maniestations. A 40-year-old man suffered from longstanding low back pain and left side sciatica which was treated with two stage operations. MRI showed multiple intradural mass lesions extending from L1 vertebral segment to S1 vertebral segment. There were no clinical and radiological manifestations of Type 2 neurofibromatosis. Histologically confirmed diagnosis was schwannoma.

광대역 통신시스템을 위한 수십 GHz 신호생성을 위한 수치 해석

김정태,Kim Jung-Tae 한국정보통신학회 2004 한국정보통신학회논문지 Vol.8 No.7

본 논문에서는 밀리미터파 대역의 신호 발생을 위한 헤테로다인 방식을 제안하였다. 향후, 무선 이동통신, 광대역 통신망에 사용되어질 밀리미터파 신호는 전기적 요소의 한계로 광학적인 요소에 의해 신호를 생성하는 방법이 많이 연구되고 있다. 광학적인 요소에 의한 여러 가지의 연구들은 주로 광검출기의 기능, 밀리미터파 대역의 발진기의 개발 등이 주로 이루어지고 있으며 무선 통신망에 적용하기 위한 소자기술 등이 발전되고 있다. 따라서 본 논문에서는 향후 밀리미터파 대역에서 사용되어질 LMDS(Local Multi-point Distribution Service) 등의 시스템에서 수십기가 헤르츠급의 광원으로 응용 가능한 헤테로다인 방식을 이용한 밀리미터파 신호의 생성에 대한 수치적인 방법에 대해 컴퓨터시뮬레이션을 통하여 검증하였다. In this paper, We have proposed an Heterodyne technique to generate millimeter-wave signal. Microwave signals in cellular broadband mobile communication networks and distributed networks can favorably be generated and distributed by optical techniques. In principle, these techniques have already been investigated for optical control of phase-array antennas, characterization of photo-detector and phase locking of millimeter-wave oscillators and now being applied to wireless communications. The generation and transmission of millimeter-wave radio signals by optical means is of interest for future pico-cell broadband mobile communication system, especially for systems operating at frequencies of 300Hz.

조명의 양과 질

김정태,Kim, Jeong-Tae 대한건축사협회 1985 建築士 Vol.1985 No.12