고온 초전도체 Y₁Ba₂Cu₃O에서 Y의 Sm 치환 효과

김채옥,김필수,김의훈,김재욱 漢陽大學校 基礎科學硏究所 1992 基礎科學論文集 Vol.11 No.-

고온 초전도체 Y₁Ba₂Cu₃O??에서 Y를 Sm으로 치환시켰을 때의 수송 임계 전류밀도와 저항의 측정은 각각 77K와 80-160K범위의 온도에서 조사되었다. 그리고 X-선 회절 분석 및 적외선 투과율 측정은 실온에서 수행되었으며, 시료들은 고상 반응법에 의해서 제조되었다. 한편 치환양이 증가함에 따라서 정상상태에서의 저항값은 증가하는 경향을 보였고, 93K 근처에서 초전도 전이온도 Tc를 갖고 있으며, 치환양에 따라 거의 변화지 않았다. 적외선 투과율 측정결과 날카로운 peak들은 472.78~618.53㎝-1범위에 있었다. 이것은 특이할 정도로의 low-lying plasmalike edge와 낮은 에너지의 전자적인 여기가 존재함을 나타내는 것이다. 수송임계 전류밀도는 43.3~123.9A/㎠ 범위에 있었다. 전이온도 Tc에 상자성 불순물의 영향이 거의 없는 것으로 보아 123phase에서 Y가 고온 초전도성에 주된 역할을 하지 않음을 알 수 있었다. The measurements of the transport critical current density and resistivity of high Tc superconductor Y₁Ba₂Cu₃O?? were made at 77K and in the range of 80~160K. X-ray pellet diffraction and IR transmittance measurements were carried out at room tempemature. The samples in which Y is replaced by Sm were prepared by solid state reaction. As substitution content increased, the normal state resistivity was increased and the superconducting transition temperature Tc near 93K did not change significantly with the substitution content. From the infrared transmittance measurements many sharp peaks were observed in the range of 472.78~618.53㎝?. It indicates that unusual low-lying plasmalike edge and low energy electronic excitation exist. The values of transport critical current densities were in the range of 43.3~123.9A/㎠. From the observation of no significant change in Tc with mangetic rare earth impurities, it could be concluded that Y plays no crucial role in the high Tc superconduction mechanisms at the 123 phase.

유도 허벅다리걸기 기술발휘 시 받기의 자세와 저항수준에 따른 중심변인 분석 사례연구(Ⅱ)

김의환,김성섭,정재욱 한국운동역학회 2005 한국운동역학회지 Vol.15 No.1

E. H. KIM, S. S. KIM, C. W. CHUNG. A Case Study on Center of Gravity Analysis when Performing ilchimata by Posture and Voluntary Resistance Levels of Uke in Judo[ II]. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 237.-257, 2005. It was to study as a following-research of "A Case Study on Center of Gravity(COG) Analysis when Performing Uchimata(inner thigh reaping throw) by Posture and Voluntary Resistance Levels(VRL) of Like in Judo[1]". The purpose of this study was to analyze the COG variables when performing uchimata(inner thigh reaping throw) by two postures and voluntary resistance Jevels(VRL) of uke(reciver) in Judo. The subjects, who were one male judoka(YH) for 1992 Barcelona Olympic Games Olympian(silver medalist), and one male trainee; Y.I.University representative member (SDK), and were filmed on two S-VHS 16mm video cameras(60fields/sec.) through 3-dimensional motion analysis methods, that postures of uke were shizenhontai (straight natural posture) and jigohontai(straight defensive posture), VRL of uke were 0% and 100%, respectively. The kinematical variable was COG variable, distance of COG, and distance of resultant COG between uke and tori(the thrower), velocity and acceleration of COG. The data of this study collection were digitized by SIMI Motion Program computed the mean values and the standard deviation calculated for each variables. When performing uchinwta according to each posture and VRL of uke and classifying. From the data analysis and discussion, the conclusions were as follows : 1. Displacement of COG Subject YH, COG was the highest in kuzushi(balance -breaking), vertical COG was low when following in tsukuri(positioning; set-up), kake(application; execution), and COG was pattern of same character each postures and resistance, respectively. Subject SDK, COG was low from kumikata(engagement positioning) to kake, and COG was that each postures and resistance were same patterns, respectively. Subject YH, SDK, each individual, postures and resistance, vertical COG was the lowest in kake phase, when performing. 2. Distance of COG between uke and tori The distance of COG between uke and tori when performing, subject YH was 0.64-0.70cm in kumikata, 0.19-0.28cm in kake, and SDK was 0.68-0.72cm in kumikata, 0.30-0.42 cm in kake. SDK was wider than YH. 3. Distance of resultant COG between uke and tori The distance of resultant COG between uke and tori when performing, subject YH was 0.27-0.73cm from kumikata to kake. and SDK was 0.14-0.34cm in kumikata, 0.28- 0.65cm in kake. Jigohontai(YH:0.43-0.73cm,SDK:0.59-0.65cm) was more moved than shizenhontai(YH:0.27-0.53cm, SDK: 0.28- 0.34cm). 4. Velocity of COG The velocity of COG when performing uchimata, subject YH was fast anterior-posterior direction in kuzushi, ant-post. and vertical direction fast in tsukuri and kake. SDK was lateral, ant.-post. and vertical direction in kuzushi, ant.-post. and vertical direction in tsukuri and ant.-post. direction in kake, respectively. 5. Acceleration of COG The acceleration of COG when performing uchimata, The trend of subject YH was showed fast vertical direction in kuzushi and tsukuri, ant-post. and vertical direction fast in kake. The trends of SDK showed lateral direction in kuzushi, lateral and ant.-post. direction in tsukuri and ant.-post direction in kake, respectively.

고온 초전도체 REBa₂Cu₃O(RE=Yb, Y, Eu, Nd)의 초전도성에 관한 연구

김채옥,김재욱 漢陽大學校 基礎科學硏究所 1992 基礎科學論文集 Vol.11 No.-

고온 초전도체 REBa₂Cu₃O??(RE=Yb, Y, Eu, Nd)의 시료들을 제조하여 결정구조와 적외선 투과율 실험을 상온에서 수행하였고, 온도에 따른 전기 저항의 변화와 자화를 측정하였다. RE의 이온 반경이 증가할수록 초전도체의 전이온도 범위가 커지며, 이는 적외선 투과율 실험에서 Cu-O mode에 의한 frequency의 증가하는 것과 일치됨이 관찰되었다. 자기 임계 전류밀도는 10³~10⁴A/㎠범위에 있었다. 고온 초전도체 REBa₂Cu₃O??에서는 희토류 자성 불순물이 전이온도 Tc에 크게 영향을 주지 않았다. High Tc superconductor REBa₂Cu₃O??(RE=Yb, Y, Eu, Nd)were prepared by solid state reaction. X-ray pellet diffraction and IR transmittance measurements were conducted at room temperature. Also the temperature dependence of the electrical resistance and magnetization was determined. The width of the transition between the normal and the superconduction state was observed to be broader as the radii of the ions. This result agrees with the observed increase in the frequency of transmission due to Cu-O modes. Magnetic critical current densities ranged from 10³~10⁴A/㎠. The localized rare earth magnetic impurities did not affect significantly the transition temperature(Tc) of high Tc superconductor REBa₂Cu₃O??(RE=Yb, Y, Eu, Nd).

일부 출판업 VDT 작업자들의 근골격계질환 자각 증상 호소율과 관련요인에 관한 연구

채창호,김영욱,이철호,김정일,김준연,이세훈 가톨릭대학산업의학센타 산업의학연구소 2003 韓國의 産業醫學 Vol.42 No.2

Objectives: This study was conducted to investigate the relationship between the self-reported musculoskeletal symptom prevalence and related factors among some VDT workers in publishing industries. Methods: The 201 study subjects consist of 130 VDT workers comprised of 59 edition workers and 71 data entry workers, and 71 Non-VDT workers. The study subjects were surveyed with structured self-reported questionnaire. Results: The prevalence of self-reported musculoskeletal symptom were 39.2% at neck, 36.2% at back and waist, 30.8% at shoulder, 25.4% at hand and wrist and 9.2% at arm on VDT workers. In logistic regression analysis. Type of VDT(data entry worker) work was related factor of musculoskeletal symptom prevalence at neck, shoulder, arm, back and waist, hand and wrist. VDT working time and working condition were related factors at back and waist. At neck, shoulder, hand and wrist, sex was one of the related factors. Conclusion: Our finding revealed that sex and type of VDT work were main related factors of musculoskeletal symptom prevalence in study subjects.

부비동내시경수술 후 후각기능의 변화

김진국,남태욱,임채형,장현종 건국대학교 의과학연구소 2002 건국의과학학술지 Vol.12 No.-

Background and Objectives: Rhinosinusitis is the most common cause of olfactory impairment and endoscopic sinus surgery is considered as a surgical procedure of choice for treating chronic sinusitis. CC-SIT (Cross-Cultural Smell Identification Test) consists of 12 items well known in most non-English-speaking cultures. Authors evaluated the therapeutic effects of endoscopic sinus surgery on olfactory dysfuction using CC-SIT. Materials and Methods: The subjects of this study were seventeen sinusitis patient who had undergone ESS from November 2001 through April 2002. All patients were divided into two groups according to nasal polyp and CT findings. CC-SIT was used for the evaluation of olfactory function. Results: Forty seven percents of patients had improvement in olfactory function postoperatively. No correlation was found between changes in CC-SIT score and nasal polyp and preoperative CT findings. Conclusion: It is concluded that nasal polyp and CT findings have no effect on olfaction.

신장도의 변화에 따른 Polyaniline 필름의 가공 및 특성

김채옥,김재욱 漢陽大學校 自然科學硏究所 1997 自然科學論文集 Vol.16 No.-

기능성산인 캠퍼슬포닉산(HCSA)으로 도핑된 free standing 필름과 N-메틸-2-피롤리디논 용액으로 용해시켜서 만든 free standing 필름등을 제조하여 이들 필름의 결정성, 전기전도도 및 전자기파차폐 특성에 대하여 조사하였다. 고도 교차결합된 필름들의 결정성 정도는 신장율이 증가함에 따라 증가하였다. NMP 용액으로 용해시킨 후 HCl로 도핑시킨 고도 교차결합된 필름의 전기전도도의 값은 173S/cm이었고, 기능성산인 캠퍼슬포닉산으로 도핑한 후 유기용매인 m-cresol에 녹여서 만든 free standing 필름의 전기전도도의 값은 210S/cm로서 고도 교차결합된 필름의 값보다 높았다. 캠퍼슬포닉산으로 도핑된 폴리아닐린 필름은 10MHz∼1GHz의 주파수 영역에서 전자기파차폐 효율이 37∼41dB이었고 이것은 고도 교차결합된 필름의 경우보다 높은 값이며, 전자기파 차폐용 물질로서의 가능성을 시사한 결과이다. Polyaniline free standing films with different degrees of elongation cast from N-methyl-2-pyrrolidinone(NMP) solution and camphorsulfonic acid(HCSA) were prepared by various processing. The properties of these films such as crystallinity, conductivity and electromagnetic shielding were investigated. The degree of crystallinity of the crosslinked films increased with increasing draw ratio. For the case of the oriented films doped with hydrochloric acid, we have the values of conductivities up to 173S/cm. We have obtained the value of conductivity 210S/cm in the HCSA doped polyaniline film cast from the solvent of m-cresol, which is higher than that of the crosslinking oriented films. The electromagnetic shielding efficiency of HCSA doped polyaniline film obtained 37∼41dB in the frequency range of 10MHz∼1GHz, which is higher than that of the crosslinking oriented films. The higher value of electromagnetic shielding efficiency of HCSA doped polyaniline film suggests strong possibility of electromagnetic shielding material.

비내시경을 이용한 안와 내벽 골절 정복 2예

김진국,남태욱,임채형,김재영,김정석 건국대학교 의과학연구소 2001 건국의과학학술지 Vol.11 No.-

Traditional surgical approaches to orbital medial wall fractures are either extraocular skin incision or indirect bicoronal flap. However these methods can leave remarkable orbital scar or scalp alopecia with possible complications. Endoscopic intranasal visualization of the medial orbital wall and lamina papyracea is a technique familar to otolaryngologists. This endoscopic view allows confirmation of fracture of medial orbital wall and herniation of orbital contents. Good visualization of the fracture can facilitate the anatomic reduction of orbital contents and the proper placement of orbital implant. Two cases of medial orbital wall fracture repaired by intranasal endoscopy using silastic sheet are reported.

고온 초전도계 Y Ho Ba₂Cu₃O의 격자진동

김채옥,김재욱 漢陽大學校 基礎科學硏究所 1993 基礎科學論文集 Vol.12 No.-

고온 초전도체 ??에서 Y대신 Ho를 치환시킨 시료를 제작하여 수송 임계전류밀도를 77K 온도에서 측정하였으며, 적외선투과율과 Raman스펙트럼 측정을 상온에서 실시하였다. 특히 Roman스펙트럼 특정은 100mW의 레이저출력에서 수직으로 편광한 경우와 수평으로 편광한 경우를 관찰하였다. 치환량의 변화에 따른 수송 임계전류밀도 값은 110~217A/㎠범위에 있었고 자기장이 증가됨에 따라 감소됨을 알 수 있었다. 적외선 투과율과 Roman스펙트럼으로부터 얻은 장이 증가됨에 따라 감소됨을 알 수 있었다. 적외선 투과율과 Roman스펙트럼 측정으로부터 얻은 Cu(1)-O(4) stretching mode는 초전도체의 결정구조를 좌우하며 산소의 영향에 강한 영향을 받는다. 또한 이것은 치환양이 증가됨에 따라 감소하는 경향을 보였다. Roman스펙트럼에서 수직 편광한 경우와 수평 편광한 경우 모두 asymmetric한 형태를 이루었다. 특히 수평편광의 경우는 BaCuO₂phase의 강도가 증가했다. High Tc superconductor ?? in which Y is replaced by Ho were prepared by solid state reaction. The measurement of the transport critical current density was determined at 77K. Infrared transmittance and Raman spectrum measurements were carried out at room temperature. The Raman spectrum measurements observed in vertical and parallel polarization at 100mW laser power. As substitution content changed. the value of transport critical current densities were in the range of 110∼217A/㎠. As the magnetic field increased, transport critical current densities were decreased. Cu(1)-O(4) stretching mode are assigned to provide a better understanding of the crystal structure and the role of oxygen defects in superconductor. Cu(1)-O(4) stretching mode were decreased with increased quantity of Ho concentration. Raman spectrum of vertical and parallel polarization were obtained as a form of typically asymmetric shape. Raman spectrum for the parallel polarization at 100mW was increased in intensity of BaCuO₂phase.

유도 업어치기 패턴에 따른 하지의 운동학적 분석

김의환,정재욱,강선영,윤현 龍仁大學校 武道硏究所 2002 武道硏究所誌 Vol.13 No.1

The purpose of this investigation was to analyze the changes of the lower limbs angle, when performing Morote-Seoinage(M.S.N.:two arm shoulder throw) in judo who was 5 females university representative judokas of light weight category in judo, and filmed on video cameras(60field/s). The data of this study digitizied by KWON3D 2.1 program computed the average and standard deviation calculated individual 5 trials with Programing Lab view 6i. From the data analysis & discussion, the following conclusions were drawn : 1) A pattern : Right vknee angle was flextion and extension Kuzushi phase and flexed in Tsukuri to Kake phase. Light knee angle flexed in the whole phase. Right·Light hip angle weren't difference changle of angle. 2) B pattern : R. knee angle had flextion and extension in Kuzushi phase and flexed in Tsukuri to kake phase. Light knee angle slowly flexed in the whole phase. Suddenly, flexed in Kake 1·2 stage. Right hip angle raised flextion and extension in Kuzushi phase and suddenly flexed in Tsukuri to Kake phase. Light hip angle slowly raised in the whole phase. 3) C pattern : C pattern was larger than A, B pattern's change of Right knee angle, this time angle was 30.4˚. Light knee angle was flextion in the whole phase. Right hip angle flexed in Kuzushi phase and largely extended, again flexed. Light hip angle firstly flexed and extended, flexed on the Tsukuri to Kake phase.

유도 측방낙법의 운동학적 변인 특성분석

김의환,김성섭,정재욱 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.14 No.2

The purpose of this study was to analyze the traits of the kinematical variables of Yoko ukemi(side breakfall) in Judo, when performing judoists. The subjects were four male judokas who were trainees Y. University Squad members and were filmed on two S-VHS 16㎜ video cameras (60fields/sec.) The kinematical variables were temporal and COG variables. The data of this study collection were digitized by KWON3D program computed the mean values and the standard deviation calculated for each variables. From the data analysis and discussion, the conclusions were as follows: When performing Yoko ukemi(side breakfall) in Jigo hontai(straight defensive posture): 1. Temporal variables, in the time required(TR) by phase, the first phase (take off phase average 0.77sec.) showed the longest time, and the next was the third phase (ukmi phase, 0.46sec.), the second phase(air phase, average 0.19sec.), and the total TR 1.42sec.(±0.13). 2. The body part touched order and TR by the mal were hip (0.98sec.) showed the shortest time, and the next was elbow (0.99sec.), hand(1.01sec.), back(1.01sec.), order, etc. respectively. We know motions that the hip part touched on the mat the first, but before receiving impact, using by arm, and touching by the palm of the hand more strong. 3. Posture variables, vertical COG variable in each event el(ready position 0.98cm) moved the highest, and the next was e2(jumping position, 69.70cm), e3(transition position, 62.42cm), e4(landing position, 40.05cm), and e5(ukemi position, 18.55cm), gradual decrease respectively.