폐염균의 항생제 감수성 검색

김수남,이동권,표석능 성균관대학교 약학연구소 1993 成均藥硏論文集 Vol.5 No.1

Streptococcus pneumoniae remains a major cause of bacteremia, meningitis, penumonia, sinusitis, and otitis media. Although this organism was originally exquisitely susceptible to penicillin, the last two decades have witnessed the emergence of strains resistant to penicillin as well as other antimicrobial agents in many parts of the world. 102 isolates obtained from patients with invasive pneumococcal disease have been examined the susceptibility to various antibiotics. 52% to 85% of isolates tested were resistant to various antibiotics. These data suggest that more powerful antibiotics should be used for the treatment of pneumococal infection.

승용차용 알루미늄 합금 휠의 진동특성에 관한 실험적 연구

金秉三,홍동표 全北大學校 1993 論文集 Vol.36 No.-

Vibration characteristics of a wheel play an important role to judge a ride comfortability and quality for a passenger car. In this study, the vibration characteristics of al-alloy and steel wheel for passenger car are studied. Natural frequency, damping and mode shape are determined experimentally by frequency response function. Results show that wheel material property, size and design are parameter for shift of natural frequency and damping.

정보통신산업의 국민경제적 위상과 전망

김용규,문석웅,홍동표 한양대학교 디지털경제연구소 2003 디지털경제연구 Vol.8 No.-

보강재의 형상이 평판의 고유진동수에 미치는 영향에 관한 연구

金泰玩,姜俊洙,表東根 弘益大學校 科學技術硏究所 1995 科學技術硏究論文集 Vol.6 No.-

An analysis is presented for the free vibration of a cantilever plate. For this papers, there are compared with the stiffener, I-shape and T-shape of the plate. The method is applied to cantilever plate with stiffened plate, I-shape and T-shape, and the natural frequencies and mode shapes of vibration are calculated numerically, given the results and confirmed experimentally.

고밀도 플라즈마에 의해 식각된 SrBi_2Ta_2O_9 박막의 표면 반응 연구

김동표,김창일,장의구 중앙대학교 기술과학연구소 2000 기술과학연구소 논문집 Vol.30 No.-

본 연구에서 SBT 박막은 Cl_2양을 변화하면서 Cl_2/Ar 가스 플라즈마를 이용하여 식각하였다. 최대 식각 속도는 Cl_2(20%)/Ar(80%) 가스혼합비에서 883A˚/min 이었다. Cl_2 가스양이 증가함에 따라서 SBT 박막의 식각 속도는 감소하였다. 이는 Ar 이온의 물리적 스퍼터링에 의한 영향이 화확 반응에 의한 식각보다 우세하게 작용함을 의미한다. 식각 메커니즘을 규명하기 위하여 optical emission spectroscopy (OES), x-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS)와 atomic force microscopy (AFM) 분석을 하였다. AFM 분석결과에서 Ar이나 Cl12 플라즈마를 이용하여 식각된 시료의 표면 거칠기 rms 값이 식각전의 시료나 Cl_2/Ar 플라즈마로 식각된 시료보다 크다. 이는 식각된 시료에서의 Bi 양의 감소나 비휘발성 식각 잔류물에 의한 영향이다. XPS와 SIMS 분석을 통하여 검증하였다. SBT thin films were etched at different content of Cl_2 in Cl_2/Ar. The maximum etch rate of SBT was 883A˚/min in Cl_2(20%)/Ar(80%). As Cl_2 gas increased in Cl_2/Ar gas plasma, the etch rate decreased. The result indicates that physical sputtering of Ar ion is dominant to chemical reaction in etching SBT thin films. To evaluate the etching mechanism of SBT thin films, optical emission spectroscopy (OES), x-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and atomic force microscopy (AFM) were carried out. From the result of AFM, the rms values of etched samples in Ar only or Cl_2 only plasma were higher than that of as-deposited, Cl_2/Ar. This can be illustrated by a decrease of Bi content or nonvolatile etching products(Sr-Cl and Ta-Cl), which are revealed by XPS and SIMS.

GF(2m)상의 타원곡선 암호 프로세서 설계

김상철,이동호,최현민,김창훈,남영진,홍춘표 대구대학교 정보통신연구소 2008 情報通信硏究 Vol.5 No.1

This paper presents a high-performance elliptic curve cryptographic processor over GF(2m). The proposed design adopts López-Dahab Montgomery algorithm for elliptic curve point multiplication and uses polynomial basis for GF(2m) field arithmetic operations. We select m=163 which is the smallest value among five recommended GF(2m) field sizes by NIST. The proposed elliptic curve cryptographic processor consists of host interface, data memory, instruction memory, control, and ALU. We simulate the proposed design using Xilinx XCV2000E hardware platform. Simulation result, we can see that our design is high flexibility and requires significantly less hardware resource compared with the previously proposed hardware implementation. 본 논문에서는 GF(2m)상의 고속 타원곡선 암호 프로세서를 제안한다. 제안한 암호 프로세서는 타원곡선 정수 곱셈을 위해 López-Dahab Montgomery 알고리즘을 채택하고, GF(2m)상의 산술 연산을 위해 다항식 기저(Polynomial Basis: PB)를 이용한다. 본 논문에서 구현한 타원곡선 암호 프로세서는 m=163을 선택하였으며 NIST(National Institute of Standard and Technology)에서 권고하는 5개의 GF(2m) 필드 크기 중에서 가장 작은 값이다. 제안한 암호 프로세서는 Host Interface, Data Memory, Instruction Memory, Control, AU(Arithmetic Unit)로 구성되어 있으며 Xilinx XCV2000E 하드웨어 플랫폼으로 시뮬레이션을 한다. 그 결과 제안된 암호 프로세서는 기존의 연구 결과에 비에 높은 확장성과 낮은 하드웨어 복잡도를 가진다.

초경공구를 사용한 Ti-6Al-4V 타이타늄 합금의 절삭가공시 공구마멸과 절삭특성에 관한 연구

김남용,홍우표,이동주 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

The machinability of Ti-6A1-4V titanium alloy and tool wear behavior when machining Ti-6A1-4V titanium alloy was studied to understand the machining characteristics. this material is one of the strong candidate materials present and future aerospace or medical applications. Nowadays their usage has already been broaden to everyday's commercial applications such as golf club heads, finger rings and many decorative items. Anticipating the general use of this material and development of the titanium alloys in domestic facilities, the review and the study of the machining parameters for those alloys are deemed necessary. this study is concentrated to the machining parameters of the Ti-6A1-4V alloy due to their dominant position in the production of titanium alloys.

調和 集中 荷重을 받고 回轉하는 타이어에서 音響 放射

김병삼,홍동표 全北大學校 1992 論文集 Vol.34 No.-

The Problem of sound radiation from rotational tire under the action of harmonic point forces is studied. The reaction on the vibratory response of the rotational tire is taken into account. The rotational tire is assumed to occupy the plane y = 0. The rotational tire material and the elastic foundation are assumed to be lossless and Bernoulli-Euler beam theory including a tension force (T), damping coefficient (C) and stiffness of foundation (k_s) will be employed. The non- dimensional sound power is derived through integration of the surface intensity distribution over the entire rotational tire. The expression for sound power is integrated numerically and the results examined as a function of wavenumber ratio (γ) and stiffness factor (ψ). Here, our purpose is to explain the response of sound power over a number of non-dimensional parameters describing tension, stiffness, damping and foundation stiffness.

요추부 유합 후 인접분절 각운동의 변화

김홍태,박봉훈,천동욱,김형표,정재호 대한척추외과학회 1995 대한척추외과학회지 Vol.2 No.1

A lumbar fusion may influence biomechanically on the remained unfused segments to take over the lost motions. The adjacent segments to fusion particulatly will experience an additional motional stress following a fusion, and then various late complications can occur. Moreover, the amount of this stress may differ according to the levels and extents of the fusions. The aim of this study is to evalu- ate this motional stress in different levels of fusion. A retrospective review of flexion and extension lateral radiograghs was undertaken for 142 consec- utive patients who had undergone various fusions in the lumbar region. Included in this study were the patients who had performed active daily livings after surgery and followed for minimum of two years. They were 60 males and 82 females, having mean age of 46.7(range 14-72). There were three posterior fusions, 123 lateral fusions, and 16 interbody fusions. The extent of fusions were one seg- ment in 71, two segments in 53, three segments in 16, and four segments in two patients. The follow- up period was 53 months in average(range 2-15 years). The intervertebral angles were measured on the flexion/extension lateral radiographs, and then the calculated intervertebral angular motions at follow-up periods were compared with those of preoperative values. The average increases of angular motion at the adjacent segments to fusions were 2.3˚at L1-2 seg- ment(ranging 0˚to 5˚increase),2.5˚at L2-3 segment(ranging 1˚decrease to 8˚increase), 2.9˚at L3-4 segment (ranging 3˚decrease to 12˚increase), 6.7˚at L4-5 segment(ranging 2˚to 18˚ increase), and 1.5˚at L5-S1 segment(ranging 5˚decrease to 7˚increase). The average increases of the above and below adjacent segments to fusions were 3.3˚(ranging 3˚decrease to 18˚increase) and 1.7˚(ranging 5˚decrease to 12˚increase) respectively. There were no significant differences in the changes of angular motion according to the extents of fusion and during these follow-up periods. In conclusion, the angular motions at the adjacent segment to fusions increased most signficantly at L4-5 segment regardless of the fusion sites whether it is below or above a fusion. Excluding the L4-5 segment, the angular motions at the above adjacent segments to fusion increased significantly compared to those at the below adjacent segments. The late complications at adjacent segments to lumbar fusions are expected to appear preferably at these segments.

지점부 다이아프램의 응력분배 거동

김동표,정경섭,김경남,양경환 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.1

These days, bridges have a tendency to be long-spanned and simple ‘ thus, the importance of economy and efficiency has increased for bridge construction. As a result, one of the main members on which interest is focused is the diaphragms. In this study, stress variation of the support diaphragms in a steel box girder was considered. This paper deals with the behavior of the stress distribution on the diaphragms on the bearings of a closed section steel box girder bridge due to the continuous casting of concrete slab. Both experimental and structural analyses were performed to verify the behavior of the stress distribution a composite steel box girder bridge under construction. Strain was continuously checked at intervals of 10 to 30 min. from the beginning of the placement by the Time Interval Function of the measuring instrument. The variation of strain on the diaphragms on the bearings are presented herein.