Clinical Characteristics of Acute Aortic Syndrome in Korean Patients: From the Korean Multi-Center Registry of Acute Aortic Syndrome

조정래,Sanghoon Shin,Jung-Sun Kim,고영국,홍명기,Yangsoo Jang,승기배,박헌식,Seung-Jea Tahk,임도선,Dong-Wun Jeon,In Ho Chae,김덕경,Junghan Yoon,정명호,최동훈 대한심장학회 2012 Korean Circulation Journal Vol.42 No.8

Background and Objectives: Acute aortic syndrome (AAS) is a heterogeneous group of disorders that often present with severe chest or back pain. It includes acute aortic dissection (AD), intramural hematoma (IMH), dissecting aneurysm, and penetrating aortic ulcer (PAU). The clinical picture of AAS and its prognosis have not been studied in a large number of Korean patients. Therefore, we organized a multi-cen-ter registry to identify the clinical characteristics and treatment patterns, as well as long-term outcomes in Korean patients with AAS. Subjects and Methods: Five-hundred twenty-eight patients, who had been diagnosed with AAS, were enrolled into this registry from 10centers. On a retrospective basis, we collected demographic, laboratory, imaging data, as well as follow-up clinical outcomes by reviewing medical records from individual centers. All the data were collected in core lab and analyzed in detail. Results: The mean patient age was 60.1±14.5 years; the male-to-female ratio was M : F=297 : 231. The prevalent risk factors for AAS in-cluded hypertension (361, 68.4%) and diabetes (52, 11.1%). The components of AAS that are included in this study are acute AD (446, 84.5%),IMH (57, 10.7%), and PAU (11, 2.1%). By type of AAS, patients diagnosed with Stanford A were 45.6% of enrolled patients, whereas those with Stanford B were 54.4% of enrolled patients. Among nearly half of the patients were treated with medicine (55.7%) alone, whereas 40.0%underwent surgery and 4.3% underwent endovascular treatment. Overall, the in-hospital event rate was 21.2% and the in-hospital death rate was 8.1%. The mean follow-up duration was 42.8 months and there showed 22.9% of total event and 10.1% of death during this period. Conclusion: By organizing a multi-center registry of AAS, we could identify the characteristics of AAS in real-world Korean patients. Further,prospective study is warranted with a larger number of patients.

충격하중을 받는 Al 박육부재의 에너지흡수 제어특성

양용준,황우채,서현경,김정호,심재기,양인영 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

In this study, concerns the crashworthiness of the widely used vehicle structure, square thin-walled tubes, which are excellent on the point of the energy absorbing capacity. An experimental investigation was carried out to study the energy absorption characteristics of thin-walled square tubes subjected to dynamic crushing by axial loading to develop the optimum structural members. The impact velocity was tested in the rage 4.698~8.2m/s. To efficiently review the collapse characteristics of these sections, the simulation have been carried out using explicit FEM package, LS-DYNA. The solutions compared with results the impact collapse experiment. Here, the controller are introduced to improve and control the absorbed energy of thin-walled square tubes in this paper. To predict and control the energy absorption, we designed it in consideration to the it's influence, height, thickness, wide ratio in this study. When the controller used, the experimental results of crushing of square tubes controlled by the controller's elements showed a good candidate for a controllable energy absorption capability in impact axial crushing.

국내 원자력발전소의 사용후핵연료 선원항 평가에 관한 연구

윤인식,정운관,김성영,염유선,심재학 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.2

우리나라에서도 원자력발전이 상용화된지 이십여년을 넘어서면서 원자력발전을 하고 있는 다른 나라와 마찬가지로 사용후핵연료 관리가 국가적인 문제로 심각히 대두되고 있다. 중간저장 시설은 1997년부터 운영예정이었으나 현재 그의 부지가 아직 확보되지 못한 상태에서 그 운전개시 시점이 불확실하다. 그리고 중간저장 이후의 사용후핵연료 정기관리 전략이 아직 마련되어 있지 못한 실정이다. 그러므로 발전소에서 발생되는 사용후핵연료 양과 그에 따른 선원항 평가는 반드시 선행되어야 할 것이다. 이제 본 연구에서는 국내 사용후핵연료 형태중 17×17에 대해서 농축도와 연소도 그리고 냉각시간별로 선원항 평가를 하였다. 사용후핵연료 선원항 평가를 위해 미국 Nuclear Regulatory Commission(NRC)의 인·허가 코드인 SCALE 코드를 이용하였다. 선원항 평가는 SCALE 코드의 모듈을 이용하였다. 선원항 평가 결과 농축도와 3.5 w/o와 연소도 35 GWD/MTU 일때 Cooling Time 0.3년은 7.5651E+16, 1년 2.8954E+16, 3년 9.8242E+15, 5년 5.4000E+15, 10년 3.0945E+15으로 계산되었으며, Cooling Time이 0.3년일때와 10년일때의 Source Term이 크게 차이가 남을 알 수 있었다. 방사선량율은 10 ㎝부터 500 ㎝ 까지 거리에 따라 선량율에 대하여 10 ㎝ 4.8365E+03(㏉/hr)에서 500 ㎝ 7.8456E+01으로 감소함을 알 수 있었다. 현재 국내 사용후핵연료에 대한 선원항 평가가 이루어지지 않았으며, Data Base 구축이 기초단계 이므로 이러한 기초자료는 추후 저장조가 건설되면 사용후핵연료 안전성과 관련하여 사용할 수 있는 것이고 기초 Data Base구축하는데 이용할 수 있을 것이다 As nuclear power has been used in our country over 20 years, spent fuel management is raised seriously as one of the national`s problems, which lies in similar situation to other countries having nuclear power plants. An interim storage facility has been planned to operate in 1997, it is highly uncertain whether this facility will start to operate by the time because the site has not been decided yet. After the intermediate storage, the spent fuel periodical management strategy has not prepared yet. Therefore it has to be preceded that the spent fuel quantity which is happening at the power station and the following source term. Now the main have evaluated the source term according to enrichment, burn-up, and cooling time for 17×17 of spent fuel form. I used the SCALE code which were certified by Nuclear Regulatory Commission(NRC) for the source term calculations of Spent Fuel. The source term was calculated, which reflected the feature of target nuclear fuel using ORIGEN-S, a module of the SCALE Code, and the exposure dose rates were calculated by using the QADS modules, considering the geometry. When the enrichment in the evaluated result of source term is 3.5 w/o and the burn-up is 35 GWD/MTU, the cooling time 0.3year is 7.561E+16(photon/second), 1year 2.8954E+16, 3year 9.8242E+15, 5year 5.400E+15, 10year 3.0945E+15 and found that the big difference in Photon Spectrum of cooling time 0.3year and 10year. I have found that radiation dose rate is decreased in 10㎝ 4.8365E+03(㏉/hr) into 500 ㎝ 7.8456E+01 for dose rate according to distance from 10 ㎝ to 500 ㎝. It is not made the source term evaluation on the domestic spent fuel, and since the data base construction is basic level, some time later, if the storage place is constructed, in connection with the safety, these basic data can be used and we can construct these basic data base.

구름 베어링의 구름마찰 특성에 관한 연구

任宰煥,金敬模,鄭寅聖 全北大學校 1995 論文集 Vol.39 No.-

In this paper, contact behaviors and decrement characteristics of rolling bearing are studied between, rolling bearing and inner and outer race, obtained by increasing of ther bolted joint force. The experiment which consists of the FFT appartus, two bearing, pulley, shaft, etc. has been proposed for the estimation of the friction force and the logarithmic decrement for various bearings. The beaarings of rolling used in this experiment are 6205 ball, 6207 ball, cylindrical roller, tapered roller bearing. The results demonstrate that the force and the logarithmic decrement of the rolling bearing increase with the type of cylindrical roller, tapered roller, 6207 ball, 6205 ball bearing in order.

인터리브가 삽입된 일방향 CFRP적층재의 동적층간파괴인성 특성

조규재,심재기,양인영 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.2

In this paper, an investigation was performed on the dynamic interlaminar acture toughness of unidirectional CFRP Laminates. Inserted interleaf the stacking sequences used in this experimentation is [ /F₂/ ]. In this experiments, Split Hopkinson's Bar test was applied to dynamic and notched flexure test. The fracture toughness of unidirectional CFRP was estimated by the analyzed deflection of the specimen and J-Integral with the measured impulsive load and reactions at the supported points. As an experimental results, the specimen [ /F₂/ ] showed greater than that of [ ] for the J-integral and displacement velocity at a measuring point within the range of experiment

상 분리 모선 시스템에서의 자계 및 와전류 특성 해석

심재학,정운관,윤인식,김성영 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.2

In the analysis of isolated phase bus bar(IPB), the magnetic field distribution generated by large current must be understood accurately. Especially, while the current of bus conductor is flowing, almost the same amount of current as the current of bus conductor is induced in the enclosures under the influence of time varying magnetic field, and the large electric loss and the deterioration of insulating capability might occur due to Joule heating effect. Therefore the optimal design of IPB satisfying the condition of minimizing the electric loss, the magnetic field distribution and eddy current characteristics around the enclosures must be analysed accurately. In this paper, the magnetic field distribution and the eddy current characteristics of three phase isolated phase bus have been studied along the phase angle by comparing the effect of eddy current on the magnetic field distribution with the case that eddy current is not considered, and also the effect of material thickness and radius of enclosure on the eddy current distribution is discussed. In the analysis of time varying magnetic field, instead of finite difference method(FDM) which is generally used, finite element method(FEM) with phasor concept is investigated under the assumption that the bus current is purely sinusoidal. The characteristics

경량화용 AI/CFRP 사각튜브의 적층각과 두께에 따른 압궤특성

임광희,양인영,이길성,조영재,김성훈 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.2

알루미늄 튜브와 CFRP(Carbon Fiber Reinforced Plastics) 튜브는 대표적인 경량화 재료이지만, 축 하중을 받을 때 압궤되는 메커니즘이 상이하다. 알루미늄 튜브는 안정적인 소성변형에 의해서 에너지를 흡수하나, CFRP 튜브는 알루미늄 튜브에 비하여 비강도, 비강성은 높으나 불안한 취성파괴에 의해서 에너지를 흡수한다. 본 논문에서는 두 재료의 단 점을 상호 보안하고 장점에 대한 상승효과를 기대하기 위하여, CFRP의 적층각과 두께변화를 주어 알루미늄 사각튜브의 외면을 감싸 적층하여 강화시킨 Al/CFRP 튜브를 가공하여 축 압궤실험을 행하여 압궤거동과 에너지흡수특성을 고찰하였다. 그리고 알루미늄 사각튜브와 CFRP 사각튜브의 압궤실험을 행하여 Al/CFRP 사각튜브와 비교하였다. 고찰결과, Al/CFRP 사각튜브의 압궤는 알루미늄 튜브의 좌굴을 계기로 하여 CFRP 튜브의 불안한 취성파괴의 단점을 보완하여 비교적 안정적인 압궤모드를 보였다. Al/CFRP 사각튜브는 CFRP 적층각과 두께에 의해 4가지 대표적인 압궤모드를 보였으며, 압궤모드는 에너지흡수 특성을 나타내는 중요한 척도가 되었다. 또한, Al/CFRP 사각튜브가 알루미늄 튜브와 CFRP 튜브에 비하여 단위 질량당 흡수에너지가 높아 경량화 효과가 크다는 것을 알 수 있었다. An aluminum or CFRP (Carbon Fiber Reinforced Plastics) tube is representative light-weight materials but its axial collapse mechamism is different from each other. The aluminum tube absorbs energy by stable plastic deformation. while the CFRP tube absorbs energy by unstable brittle failure with higher specific strength and stiffness than those in the aluminum tube. In an attempt to achieve a synergy effect by combining the two members. aluminum/CFRP square tubes were manufactured. which are composed of aluminum tubes wrapped with CFRP outside aluminum square tubes with different fiber orientation angle and thickness of CFRP. and axial collapse tests were performed for the tubes. The crushing behavior and energy absorption capability of the tubes were analyzed and compared with those of the respective aluminum square tubes and CFRP square tubes. Test results showed that the collapse of the aluminum/CFRP square tube complemented unstable brittle failure of the CFRP square tube due to ductile characteristics of the inner aluminum square tube. The collapse modes were categorized into four modes under the influence of the fiber orientation angle and thickness of CFRP. The absorbed energy per unit mass, which is in the light-weight aspect, was higher in the aluminum/CFRP square tube than that in the aluminum square tube or the CFRP square tube alone.

CFRP적층쉘의 적층구성 및 곡률반경에 따른 관통특성

임광희,조영재,이길성,심재기,김영남,양인영 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

최근 탄소섬유 강화 복합재료(이하 CFRP)는 비강도, 비강성이 높아 경량화가 요구되는 우주항공분야에서 구조용 재료로 널리 이용되고 있다. 본 연구에서는 CFRP 적층쉘의 적층구성 및 곡률반경에 따른 관통 특성을 고찰 하고자 한다. 실험에 사용된 복합재료는 일방향 프리프레그시트로서 적층방법은 〔0₃/90₃〕, 〔0₂/90₂〕s,와 〔0₂/90₃/0〕s, 〔0/90₂/0〕 2계면과 4계면으로 적층하였다. 그리고 다양한 곡률 반경을 적용하였다. (R= 100, 150, ∞). 적층순서에 맞게 적층된 시험편은 경화온도 130℃에서 진공백 성형과정을 오토클레이브로 제작 하였으며 100x140mm 크기로 절단 하였다. 시험편은 강구로 관통시켰으며 ballistic-screen sensor로 속도를 측정하여 충격전 운동에너지와 충격 후 운동에너지를 구할 수 있다. 흡수에너지는 곡률이 커질수록 증가하였으며 4계면 시험편보다 〔0₃/90₃〕s 와 〔0₂/90₂〕s 적층구조를 갖는 2계면 시험편이 흡수에너지가 더 높게 나왔다. Currently, carbon-fiber reinforced plastics (CFRP) are widely used in both space and civil aircraft due to their superior stiffness and strength to weight ratios compared to conventional metallic materials. This paper is to study the effects of curvature and staking sequence on the penetration characteristics of CFRP laminated shell. Composite laminates used in this test are CFRP orthtropic laminated plates, which are stacked with two-interfaces 〔0₃/90₃〕s, 〔0₂/90₂〕s and 〔0₂/90₃/0〕s. 〔0/90₂/0〕s. They are manufactured to varied curvature radius (R= 100. 150, 200 mm and ∞). They are cured by heating to the appropriate hardening temperature(130℃) by mean of a heater at the vacuum bag of the autoclave. Test specimens were prepared with dimensions 100mmx140mm. When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determining the time for it to pass two ballistic-screen sensor located a known distance apart. Absorbed energy increased as the curvature increased. 〔0₃/90₃〕s and [0₂/90₂〕s specimens, which is small interlaminar number, was higher than fore interlaminar specimen.

SHIELDING ANALYSIS OF DUAL PURPOSE CASKS FOR SPENT NUCLEAR FUEL UNDER NORMAL STORAGE CONDITIONS

Ko, Jae-Hun,Park, Jea-Ho,Jung, In-Soo,Lee, Gang-Uk,Baeg, Chang-Yeal,Kim, Tae-Man Korean Nuclear Society 2014 Nuclear Engineering and Technology Vol.46 No.4

Korea expects a shortage in storage capacity for spent fuels at reactor sites. Therefore, a need for more metal and/or concrete casks for storage systems is anticipated for either the reactor site or away from the reactor for interim storage. For the purpose of interim storage and transportation, a dual purpose metal cask that can load 21 spent fuel assemblies is being developed by Korea Radioactive Waste Management Corporation (KRMC) in Korea. At first the gamma and neutron flux for the design basis fuel were determined assuming in-core environment (the temperature, pressure, etc. of the moderator, boron, cladding, $UO_2$ pellets) in which the design basis fuel is loaded, as input data. The evaluation simulated burnup up to 45,000 MWD/MTU and decay during ten years of cooling using the SAS2H/OGIGEN-S module of the SCALE5.1 system. The results from the source term evaluation were used as input data for the final shielding evaluation utilizing the MCNP Code, which yielded the effective dose rate. The design of the cask is based on the safety requirements for normal storage conditions under 10 CFR Part 72. A radiation shielding analysis of the metal storage cask optimized for loading 21 design basis fuels was performed for two cases; one for a single cask and the other for a $2{\times}10$ cask array. For the single cask, dose rates at the external surface of the metal cask, 1m and 2m away from the cask surface, were evaluated. For the $2{\times}10$ cask array, dose rates at the center point of the array and at the center of the casks' height were evaluated. The results of the shielding analysis for the single cask show that dose rates were considerably higher at the lower side (from the bottom of the cask to the bottom of the neutron shielding) of the cask, at over 2mSv/hr at the external surface of the cask. However, this is not considered to be a significant issue since additional shielding will be installed at the storage facility. The shielding analysis results for the $2{\times}10$ cask array showed exponential decrease with distance off the sources. The controlled area boundary was calculated to be approximately 280m from the array, with a dose rate of 25mrem/yr. Actual dose rates within the controlled area boundary will be lower than 25mrem/yr, due to the decay of radioactivity of spent fuel in storage.

전력수용가포털을 위한 구내 통신 및 컴퓨터 네트워크 용량 설계

홍준희(Jun-Hee Hong),최중인(Jung-In Choi),김진호(Jin-Ho Kim),김창섭(Chang-Sub Kim),손성용(Sung-Young Son),손광명(Kwang-Myung Son),장길수(Gil-Soo Jang),이재복(Jea-Bok Lee) 한국조명·전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.10

고전력수용가포털(Consumer Portal)은 소비자의 다양한 장치들과 광역 네트워크, 그리고 에너지서비스사업자 (ESP: 한전 등)의 서비스 애플리케이션 플랫폼을 연결하는 물리적 링크이자 논리적 결합으로, 전력서비스 체계에서 소비자-공급자 간 정보교환과 서비스 거래를 담당하는 양방향 통신의 핵심 인프라로서 포털이다. 전력수용가포털(Consumrr Portal)의 성공적인 설계와 개발을 위해서는 효율성, 경제성, 확장성을 고려한 네트워크 설계가 선행되저야 한다. 그러나 전력수용가 포털의 네트워크 설계에 필요한 네트워크 용량 설계 모델링에 대한 공학적 연구는 아직 부족한 실정이다. 본 논문에서는 전력수용가포털의 네트워크 설계에 필요한 네트워크 용량 설계 모델링 방법을 논하고 실제 구축중인 시스템에 적용하였다. 그 결과 기존 네트워크 설계방법의 문제점을 파악하고, 개선하여 네트워크의 최대수용 단말기의 수를 30~40배 증대시킬 수 있는 데이터 수집 알고리즘을 개발할 수 있게 되었다. Consumer Portal is defined as a combination of hardware and software that enables two-way conmunication between energy service providers(ESP, like KEPCO) and equipment within the consumer's premises. The portal provides both a physical link (between wires, radio waves, and other media) and a logical link (translating among language-like codes and etiquette-like protocols) between in-building and wide-area access networks. Thus, the consumer portal is an important, open public shared infrastructure in the future vision of energy services. In this paper, we describe a new methodology for local communication and computer network capacity design of consumer portal, and also presents capacity calculation method using a network system limitation factors. By the approach, we can check into the limitations of existing methods, and propose an improved data processing algorithm that can expand the maximum number of the networked end-use devices up to 30-40 times. For validation, we applies the proposed methode to our real system design. Our contribution will help electrical power information network design.