한국산 날치과(Beloniformes , Exocoetidae)어류 5 종의 분류학적 재검토

김종만,김진구,유정화,조선형,명정구,강충배,김용억 한국어류학회 2001 韓國魚類學會誌 Vol.13 No.2

Taxonomic review of the five flyingfishes, Parexocoetus mento (Valenciennes), Cheilopogon agoo (Temminck et Schlegel), Cheilopogon heterurus doederleini (Steindachner), Cheilopogon cyanopterus (Valenciennes), Hirundichthys oxycephalus (Bleeker) were carried out based on samples collected from the South sea and around sea of Jeju Island of Korea from 1996 to 1998. Parexocoetus mento (Valenciennes) and Cheilopogon cyanopterus (Valenciennes) were revealed as the unrecorded species in Korea, which were named as "Men-to-hwang-nal-chi" and "Ki-geom-nal-chi" respectively. Parexocoetus mento is differed from P. barchypterus in having no chin barbels in juveniles, and Cheilopogon cyanopterus is distinguished from C. agoo in the branched form of pectoral fin rays and from C. heterurus doederleini in the numbers of the dorsal fin ray and the color of pectoral fins.

B 첨가 고탄소강의 흑연화에 미치는 냉간압연의 영향

박영구,우기도,이창희,류재화,나종필 한국열처리공학회 1999 熱處理工學會誌 Vol.12 No.2

The graphitization is affected by the addition of small amount of the elements(such as Si, Al, Ni, B, Cr and Mn etc.) and the pre-treatment(such as cold rolling). Boron is well known element to accelerate the graphitization of cementite in high carbon steels. Also, cold rolling is known to accelerate the graphitization. But the graphitization nucleation mechanism by cold rolling is few reported. Therefore the effect of cold rolling in Fe-0.5%C-1.0%Si-0.47%Mn-0.005%B steel on the graphitization is investigated quantitatively using hardness test, optical microscope and scanning electron microscope, neutron induced microscopic radiography. The nucleation of graphite in cold-rolled Fe-0.5%C-1.0%Si-0.47%Mn-0.005%B steel is formed at void which is formed at pearlite/pearlite boundary by cold rolling. But the effect of cold rolling on graphitization in boron addition steel is more effective than that of no boron addition steel due to segregation of BN at void in boron addition steel.

안전 검증을 위한 회전 불변 지문인식 시스템

이승현,류대현,박민순,류충상 한국산업안전학회 1999 한국안전학회지 Vol.14 No.2

본 논문에서는 안전검증 분야로의 응용을 위하여 circular harmonic filter(CHF)와 binary phase extraction joint transform correlator(BPEJTC)에 근거한 회전불변 지문인식 시스템을 제안하였다. 본시스템은 이동 및 회전 변화에 강건하며 실시간으로 지문을 인식할 수 있는 특징을 지닌다. 실시간 구현을 위하여 회전불변 특성을 얻기 위한 복소 CHF는 실수로 구성된다. 시뮬레이션을 통해 본 시스템이 회전된 지문에 대해 강건한 특성이 있음을 보였다. We propose a rotation invariant fingerprint identification system based on the circular harmonic filter (CHF), and binary phase extraction joint transform correlator (BPEJTC) for validation and security verification. It is shown that this system has the shift and rotation robust properties and can recognize the fingerprint in real-time. The complex circular harmonic filter, which is used to obtain the rotation invariance, is converted into the real-valued filter for real-time implementation. Experimental results show that this system has a good performance in the rotated fingerprints.

리튬이차전지용 Li1.05CoO2 음극재료의 전기화학적 특성 연구

김정식,우선기,류호진,이학로,김인석 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.7

A Li_(1.05)CoO₂ powder has been prepared by the solid state reaction of Li₂CO₃ and Co₃O₄ at 1000℃. Li_(1.05)CoO₂ powder was characterized a layered structure with space group of R3￣m by XRD analysis. But Li_(1.05)CoO₂ has a shorter c-axis than LiCoO₂ because, in the former case, a coulombic interaction is more dominent than elastic strain energy effect. In this experiment, electrochemical properties about porous Li_(1.05)CoO₂ were investigated by galvanostatic, CV(Cyclic Voltammetry) and GITT(Galvanostatic Intermittent Transient Technique) method.

Mn, Fe, Ni 첨가가 급속응고/분말야금법으로 제조된 Al-Zn-Mg-Cu 계 합금의 응력부식균열 거동에 미치는 영향

김상식,류재철,임수근,이명호 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.11

Stress corrosion cracking behaviors of RS/PM Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Fe, 2%Mn, and 1%Fe+1%Ni, respectively, were examined in the present study. Each alloy was exposed to 3.5% NaCl aqueous solution under an applied stress of 200MPa for 5 and 20 days, respectively, and tensile tested in air. The alloys containing Fe+Ni and Mn showed a significant reduction in ductility after exposure for 20 days. SEM fractographic studies indicated that the size and depth of dimples, as well as the sign of plastic deformation around dimples, were greatly reduced after exposure for those alloys susceptible to stress corrosion cracking. The present study strongly suggested that hydrogen played an important role in stress corrosion cracking behaviors of Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Mn and 1%Fe+1%Ni, respectively.

보수 보강된 철근콘크리트 보의 휨 및 전단 거동에 관한 연구

김태봉,이재범,류택은 한국산업안전학회 1999 한국안전학회지 Vol.14 No.1

This study presents test results of RC beams strengthened by steel plates, carbon fiber sheets(CFS) and aramid fiber sheets(AFS) for increasing flexural and shear resistance. The test was performed with different parameters including the type of strengthening materials, flexural-strengthening methods and shear-strengthening methods. In case of flexural test, RC beams are initially loaded to 70% of the ultimate flexural capacity and in case of shear test loaded to 60 or 80 percent of the ultimate shear capacity and subsequently reinforced with steel plates, CFS and AFS. Experimental data on strength, steel strain, deflection, and mode of failure of the reinforced beams were obtained, and comparisons between the different shear reinforced schemes and the non-strengthened control beams were made. The test results showed that damaged RC beams strengthened by steel plates, CFS and AFS have more improved the flexural and shear capacity. For the beams with external reinforcement by steel plates, aramid fiber sheets and carbon fiber sheets increases in ultimate strength of 4 to 21, 17 to 43 and 26 to 36 percent were respectively achieved. Initial load had small effect on strength after reinforcement, but an important influence on deflection. One sheet reinforced was stronger than two sheets reinforced but less deflected than two sheets reinforced.

304 스테인리스강의 항균성에 미치는 Cu 의 영향

김기돈,유승기 대한금속재료학회(대한금속학회) 2001 대한금속·재료학회지 Vol.39 No.2

Recently, in the line with the growing interest of sanitary problem, the requirement for the development of anti-bacterial material has been an issue with more weight. In Japan, not only some steel makers already completed the development of the anti-bacterial stainless steel, but other makers are also showing an interest in that subject. The function anti-bacterial power of stainless steel is closely related with the addition of Cu element. In this case, Cu decomposes as Cu^(2+) and reacts with COA-SH enzyme which acts as a catalyst in respiratory process of bacteria, resulting in deactivation of the enzyme. The current study derived an optimum anti-bacterial alloy composition, proper process conditions including heat treatment and the overall comparison with the previous developed POSCO-304J1 stainless steel. With the proper heat treatment the anti-bacterial power of the developed alloy is increased due to the uniform distribution of ε-Cu precipitates (0.5∼1.0 ㎛) restraining the formation of passive film on the steel surface.

10Cr-MoVNbN 강의 질소함량증가에 따른 미세조직과 기계적 특성

김성호,송병준,조성석,류우석 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.8

Microstructure and mechanical properties of 10Cr-MoVNbN steels with increasing nitrogen contents were investigated. The nitrogen contents of the steels were 0.025 wt%(N02) and 0.045 wt%(N05), respectively. After tempering, the microstructure of the steels consisted of the tempered martensite matrix and various precipitates(M_(23)C_6, Nb(C, N), Cr₂N, V(C, N)). V-rich fine precipitates(5-20 ㎚) observed in the N05 steel hindered the movement of dislocation and consequently delayed formation of subgrain during tempering. It is clarified by transmission electron microscopy that Cr₂N nitride starts to precipitate at a lower tempering temperature and to decompose at a higher tempering temperature in the N05 steel than in the N02 steel. With increasing nitrogen content, hardness, tensile strength, high temperature creep strength and creep rupture elongation increased, but impact property and minimum creep rate decreased.

보험회사 리스크관리 감독정책에 관한 연구 : 보험회사를 대상으로 한 설문조사분석을 중심으로

류건식,정석영 한국보험학회 2001 保險學會誌 Vol.60 No.-

본 연구는 보험회사의 입장을 고려하여 향후 리스크관리 감독체제의 방향 설정을 주목적으로 하고 있으며 이를 위하여 보험회사를 대상으로 설문조사를 실시·통계분석을 실시하였다. 분석 결과 금융감독원에서 작성한 리스크관리 체크리스트 활용미흡, 회사내의 공감대를 형성할 수 있는 리스크관리 실행전략 수립이 미흡, 전문인력의 양성 및 확보가 미진한 점으로 지적되었다. 리스크관리 정책 및 경영의 중요성에 대한 전문가 의견은 리스크관리의 인식의 중요성, 회사 실정에 맞는 자체적 실천방안, 독립적인 리스크관리조직의 필요성, 최고경영자의 리스크관리 인식전환, 전문인력확보 등이 시급한 것으로 조사되었다. 또한 이러한 의견들은 보험회사의 특성에 기인하여 몇 가지의 문항에서 보험회사간 중요성의 정도 차이가 존재하였지만 대부분 생/손/외국계 보험회사의 전문가가 판단한 중요도는 일치하고 있었다. 향후 보험회사 리스크관리 감독규정은 이러한 점을 감안하여 방향설정이 이루어져야 할 것이다. This paper aims to suggest the risk management (RM) regulation policies by focusing on the insurance corporations. Our results are based on the extensive survey among 35 insurance corporations. The analysis of survey with respect to the current circumstances of RM among insurance corporations reveals as follows; the absence of practice in checklist provided by Financial Supervisory Service, lack of risk RM strategy planning, lack of in-house RM professionals and their training programs. The survey of the RM specialists reveal that the most imminent probiems are as follows; insufficient understanding of top management, absence of practical RM strategy planning and not independent RM organization, lack of RM experts, and so on. Also our statistical results indicate that there is no difference among Life/Property and Liability/Foreign insurance corporations even though only a few opinions are different from each other because of the unique characteristics of their businesses. These results could provide some suggestions and implications for RM regulation policies.

소태산 친제의 『육대요령』 고찰

류성태 한국원불교학회 2001 圓佛敎學 Vol.6 No.-

This study is focused on the the innitial book of Won Buddhism. It is Yuk-Dae-Yo-Ryung, The Ways of Six Essentials which show its early theory. Furthermore, it is to inform the forming history of Won Buddhist doctrine by studying its structures on the basis of Great Master Sotaesan. The innitional Sutras of Won Buddhism appears as The Ways of Six Essentials, The Ways of Three Essentials and Buddhist Sutra. So, Sotaesan had published these sutras with the help of Jungsan who is the successor of his religious order.