[논문]베이스플레이트의 비선형 거동에 관한 연구

김재봉,이치형,윤성기 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

본 연구에서는 편심하중이 작용하는 철골 주각부의 모멘트-회전거동에 대한 실험적인 결과와 ANSYS 프로그램을 이용하여 베이스플레이트의 비선형 거동특성을 파악하는데 목적이 있다. 또한,베이스플레이트의 비선형 거동에 영향을 미치는 여러 변수들을 고려하였으며, 실험과 유한요소 해석을 통하여 비교하였다. 그 결과 주각부의 회전거동은 반강접성을 나타내며 베이스플레이트의 설계와 골조의 거동해석에 중요한 영향을 미치는 것으로 판단된다.

염화비닐 노출 근로자의 시료채취시기에 따른 요중 thiodiglycolic acid의 농도 변화

김현수,김치년,원종욱,차봉석,이경종,노재훈 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 본 연구는 염화비닐 및 폴리염화비닐수지 제조공장의 VCM 노출 근로자들을 대상으로 소변 시료채취 시기에 따른 요중 TDGA 농도의 변화를 알아보고자 하였다. 방법: VCM 및 PVC 제조공장 남성 근로자 31명을 대상으로 공기중 VCM 개인노출평가를 실시하였으며 소변내 TDGA 배설 양상을 알아보기 위해 3일 휴식 후 척 작업 시작 전(TDGA1), 1일 작업종료 후(TDGA2), 1일 작업 한 다음날 작업 전(TDGA3) 소변을 채취하였다. VCM에 노출되지 않은 대조군 30명에 대해 작업종료 후 소변을 채취하였다. 공기 중 VCM의 측정 및 본석은 NIOSH 공정시험법 No. 1007에 따라 실시하였다. 요중 TDGA 분석을 위하여 소변을 trimethylsilyldiazomethane(2.0 M in diethyl ether)으로 메틸화 반응하여 가스크로마트그래피/펄스불꽃광도검출기로 분석하였다. 결과: VCM 노출 후 요중 TDGA가 배설되어 감소하는 시기를 조사하기위해 대조군과 VCM 노출 근로자들의 3일 휴식 후 작업 시작 전 요중 TDGA 농도 (TDGA1)를 비교한 결과 각각 0.179±0.271 mg/g creatinine, 0.218±0.443 mg/g creatinine으로 통계학적으로 유의한 차이가 없었다. 1일 작업 종료 후 요중 TDGA 농도(TDGA2)는 0.434±0.623 mg/g creatinine, 1일 작업 한 다음날 작업전 요중 TDGA 농도(TDGA3)는 0.767±1.056 mg/g creatinine으로 순차적으로 증가하였다. 하루 노출량을 평가하기 위해 공기 중 VCM 농도와 요중 TDGA와의 단순회귀분석 결과 1일 작업한 다음날 작업 전 요중 TDGA 농도(TDGA3)와 공기 중 VCM 농도와의 관련성은 R^(2)=0.4215로 1일 작업종료 후 요중 TDGA 농도(TDGA2)보다 높았다. 결론: VCM 노출 후 3일이 경과하면 대조군의 요중 TDGA 농도 수준으로 감소하여 요중 TDGA의 배설 반감기가 3일 이내인 것으로 판단된다. 또한, 하루 근무하고 그 다음날 작업 전에 채취한 요중 TDGA 농도(TDGA3)가 전날 근무시의 VCM노출량과 상관성이 가장 높아 하루 동안의 VCM노출을 평가하기 위한 유용한 생물학적 지표로 사용할 수 있을 것으로 판단된다. Objectives: The study was performed to investigate the changes of urinary thiodiglycolic acid (TDGA) concentration in workers exposed to vinyl chloride monomer (VCM) according to the time of sampling urine. Methods: The personal exposure to airborne VCM was assessed and urinary TDGA concentration was sampled in 31 workers employed in a VCM and polyvinyl chloride (PVC) manufacturing factory. Urinary TDGA was sampled three times: before the start of the shift after 3 days off (TDGA 1), after the end of the first-day shift (TDGA2) and before starting the following day shift after completing the one- day shift (TDGA3). Urinary TDGA in 30 workers who had not been exposed to airborne VCM was sam- pled after the end of the shift. A gas chromatography/pulsed flame photometric detector (GC/PFPD) was utilized to analyze TDGA concentration in urine after the urine was methylated with trimethylsilyldia- zomethane (2.0M in diethyl ether). Results: The creatinine level was 0.179±0.271 mg/g in the control workers and 0.218±0.443 mg/g in the workers before the start of the shift after 3 days off (TDGA1), showing no significant difference (p=0.7035). Urine samples were compared according to sampling time in order to investigate the change of urinary TDGA concentration in the case of continuous exposure to airborne VCM. In VCM-exposed workers, urinary creatinine concentration was 0.434±0.623 mg/g in TDGA2 and 0.767±1.056 mg/g in TDGA3, which indicated a gradual but significant increase (p=0.024). In terms of the statistical correlation between airborne VCM and urinary TDGA to evaluate exposure dose per day, of the three urinary TDGA concentrations, TDGA3, showed the highest degree of regression (R^(2)=0.4215) with 8h-TWA airborne VCM concentration. Conclusion: Based on this result, the excretion half-life of urinary TDGA was assumed to be less than 3 days, because the concentration of urinary TDGA at 3 days after exposure to airborne VCM was decreased to the level of urinary TDGA concentration in the control workers. The concentration of urinary TDGA increased in the case of continuous shift, due to the accumulation of residual metabolites of TDGA. It was considered that TDGA3 can be applied as a useful biological index to evaluate the exposure dose of airborne VCM during one day because TDGA3 showed the highest correlation with the exposure dose of airborne VCM in the previous shift day.

컨테이너 터미널의 효율적 운영을 위한 의사결정지원시스템

김갑환,김홍배,윤원영,김종훈,권봉재,조지운 釜山大學校生産技術硏究所 1998 生産技術硏究所論文集 Vol.55 No.-

A decision support system is introduced for the efficient operation of port container terminals. It consists of ship planning subsystem, yard planning subsystem, resource management subsystem, real-time control subsystem, and simulation subsystem. The system is intended to support the planning process of the planners and the operation process of the administrators in the container terminals. It is assumed that the transfer crances and the yard tractor/trailers are used to handle containers in the marshaling yard. The system is explained in terms of the functions of each subsystem and the data flows among various subsystems.

편심경사진 내부크랙을 가진판이 순수굽힘을 받는 경우의 응력확대 계수에 대한 광탄성실험해석

이치우,김태규,조상봉 慶南大學校 附設 工業技術硏究所 1985 硏究論文集 Vol.3 No.-

편심경사진 내부크랙을 가진판이 순수굽힘을 받는 경우에 대한 광탄성실험결과 판의 폭이 크랙의 길이에 비해 충분히 큰 경우에는 문헌(9), (14)의 근사이론식과 잘 일치되었고 유한판에서는 응력확대계수의 값이 변의 영향을 많이 받음을 알 수 있었다. 크랙의 진전각도는 광탄성실험을 통해 쉽게 알 수 있으며 최대전단응력이 최소가 되는 방향으로 일어남을 알았다. The stress distribution in the vicinity of the crack tip in elasticbody under various external loads has been investigated and solved both theoretically and experimentally when the "Mechanics of Fracture" began to reveal itself to be a new method for the analysis of fracture of meterials this paper was studied for stress intensity factors of a sheet with an eccentrically inclined crack subjected to pure bending moment by photoelastic method. In this case, the experimental results of stress intensity factors for the crack inclined angle and the distance of the crack center from the neutral axis were very approximately with of the reference (9) and (14) Moreover, we easily know that the initial crack growth takes place in the directinn along which the maximum shearing stress possesses a minimum value from photoelastic experimental.

Mo¨ssbauer Parameters of Fast Neutron-irradiated Nuclear Pressure Vessels at Room- and Liquid nitrogen-temperature

이용곤,김형상,홍치유,유연봉 동국대학교 자연과학연구원 2000 자연과학연구 논문집 Vol.5 No.-

The embrittlement of fast neutron-irradiated reactor pressure vessel (RPV) steels was investigated by X-ray diffraction patterns at room temperature and Mo¨ssbauer spectroscopy at room- and liquid nitrogen-temperature. Neutron fluence on the samples were 1012, 1013, 1014, 1015, 1016, 1017, 1018n/cm². The X-ray diffraction patterns at room temperature showed that the structure of neutron unirradiated sample was bcc type, where as but the neutron irradiated samples with the fluence higher than 1017 n/cm² were so severely damaged, that bcc type structure disappeared. The Mo¨ssbauer spectra of all samples showed superposition of two or more sextets. In this paper all Mo¨ssbauer spectra were fitted by three set of sextet. The isomer shift and quadrupole splitting values were found around zero. At liquid nitrogen temperature, magnetic hyperfine field increase rapidly to 480 ∼ 552 kOe at S1 sextet in the samples of 1017∼1018n/cm² neutron fluences. And room temperature, magnetic hyperfine field also increased rapidly to 480 ∼507 kOe at S1 sextet in the samples of 1017∼1018n/cm²neutron fluences. This rapid increase of magnetic hyperfine field was infered to be caused by the change of 56Fe, 55Mn into 57Fe by neutron irradiation.

부신 결핵에 의한 Addison씨병 1예

송치운,구본정,안봉수,전준식,안미애,이진홍,송민호,김영건,노흥규 충남대학교 의과대학 지역사회의학연구소 1995 충남의대잡지 Vol.22 No.2

Addison's disease is a rare primary adrenal insufficient disorder resulting from chronic deficiency of adrenal cortical hormones. Clinical manefestations are generalized weakenss, weight loss, hyperpigmentation (especially sun exposed area and mucous membrane), hypotension, hyponatremia, hyperkalemia, gastrointestinal symptoms (involving anorexia, nausea, vomiting, abdominal pain). A 34-year-old woman has experienced slowly progressive generalized weakenss and skin pigmentation, anorexia, nausea, vomiting with ascites and diffuse abdominal pain. On the time of admission, her main clinical manifestations were anorexia, nausea, vomiting, fatigue, generalized weakness, amenorrhea, hair loss, diffuse abdominal pain revealed as Addison's disease due to bilateral adrenal tuberculosis. Her adrenal insufficient symptoms were recovered with the replacement of adrenocortical hormones and antituberculous medications. After treatment, Her skin pigmentation was decreased and menstruation was reappeared. Here we experienced one cases of Addison's disease with tuberculous peritonitis.

복합재료 샌드위치 판의 고유 진동수에 대한 탄성보의 영향

이봉학,원치문,이정호,김성환 江原大學校 産業技術硏究所 1997 産業技術硏究 Vol.17 No.-

For each construction material used, there is certain theoretical limit in sizes. For tall building construction, the reduction in slab weight is the first step to take in order to break such size limits. In this paper, the feasibility of such objective is proven and given by numerical analysis result. For a typical building slab, both concrete and advanced composite sandwich panels are considered. The concrete slab is treated as special orthotropic plate to obtain more accurate result. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. Finite difference method is used for this purpose, in this paper. The influence of the modulus of the foundation on the natural frequency is thoroughly studied.

축하중과 첨가질량이 작용하는 적층복합판의 진동해석

이봉학,김경진,원치문,성기태 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. IN this paper, hte result of application of this method to the laminated plates with axial forces and with attached point mass/masses is presented. Both N? and N? forces are considered. The solution for the laminated plates with arbitrary boundary conditions and irregular section can be obtained by simply obtaining the deflection influence coefficients by any method. The effect of neglecting the mass of the plates on the natural frequency, as the ratio of the point mass/masses to the plate mass increases, is thoroughly studied. The influence of N? and N? is also carefully investigated.

알코올 의존과 후보 유전자들간의 연관성 연구

정인원,김헌,홍주봉,지경환,이규영 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.6

연구목적 : 알코올 대사와 중추신경계내의 알코올 작용부위와 관련한 일부 후보유전자들이 알코올 의존과 관련이 있는지를 확인하고자 하였다. 방 법 : DSM-IV로 진단된 알코올 의존 환자 128명과 정상 대조군 128명을 대상으로 후보 유전자들의 다형성을 중합효소 연쇄반응과 제한효소처리법을 이용하여 동정하였다. 여기서 분리된 대립유전자와 유전자형에 따른 빈도의 차이를 유전자별로 각각 비교하였으며, 알코올 의존에 작용하는 서로 다른 유전자들에 의한 영향력을 배제하기 위하여 logistic regression 분석을 적용하였다. 결 과 : 알코올 의존군에서는 ALDH_2 유전자의 NN(wild type)형이 정상대조군에 비하여 유의하게 많았다(chi-square test, p<0.001). logistic regression analysis를 통하여 다른 유전자들에 의한 영향을 보정한 상태에서 ALDH_2가 NN(wild type)인 경우 다른 아형에 비하여 알코올 의존에 대한 odds ratio는 130.312이며 그 신뢰구간은 (17.22, 986.43)이었다. 한편, ASA는 N-glycosylation 부위에 변이형 대립유전자를 갖고 있는 경우(AG or GG)는 wild type에 비하여 알코올 의존에 대한 위험도는 2.344배이며 그 95% 신뢰구간은 (1.128, 4.871)이었다. 결 론 : 알코올 의존과 ALDH_2 유전자간에는 밀접한 연관성이 확인되었다. 또한 다른 유전자들은 개별 연관분석에서 의미있는 연관성이 관찰되지는 않았지만 logistic regression analysis를 통하여 N-glycosylation 부위에 다형성이 있는 ASA 유전자가 알코올 의존과 관련이 있음을 시사하였다. Objectives : This study was to explore the association between alcohol dependence and five candidate genes related to the metabolism of alcohol and the enzymes of the suspected sites in CNS. Methods : The genotype and allele frequencies of five candidate genes in 128 male hospitalized patients who met DSM-IV criteria for alcohol dependence were compared with 128 age-matched healthy male control subjects using polymerase chain reaction and restriction fragment length polymorphism. A logistic regression analysis was applied in order to exclude the reciprocal interactions among five candidate genes. Results : The NN genotype frequency of the ALDH_2 gene was significantly higher in alcoholic patients than in control subjects(chi-square test, p<0.001). No difference in frequency was found in the other four genes. In a logistic regression analysis, the odds ratio for alcohol dependence in the NN genotype of the ALDH_2 gene and AG or GG genotypes of the N glycosylation site on the ASA gene were 130.312(95% confidence interval, 17.22-986.43) and 2.344(95% confidence interval. 1.128-4.871), respectively. Conclusion : The result reiterates the association of the ALDH_2 gene polyporphism and the alcohol dependence. Logistic regression analysis additionally suggested that the N-glycosylation site on the ASA gene was associated with alcohol dependence.

전처리방법에 따른 산화에틸렌 분석법의 평가

이신영,김치년,조영봉,오상용,노재훈 한국산업위생학회 2003 한국산업보건학회지 Vol.13 No.2

The limit of detection(LOD), pooled coefficient of variation(pooled CV), desorption dffciency(DE), and stability after desorption by pre-treatments was compared and evaluated for analyzing the Ethylene oxide(EO) sampling on HBr-coated Charcoal tube, The results were as follows: 1. The EO's LOD was 2,483ug/sample when using the desorptin solvent, benzene : CS2(99:1), and 1.919ug/sample after using DMF. The result of the sample that passed DMF desorption and was derivativized was 1.301ug/sample. 2. EO's pooled CV was 0.00503 when using the solvent benzene:CS(99:1), after desorption with DMF, the result was 0.00329, and the result of those derivativized by DMF desorption was 0.00514. 3. EO's DE using the solvent benzene:CS(99:1) was 92.13%, atter desorption with DMF, it was 102.75%, and the result of those studied after being derivativized by DMF desorption was 96.47%. 4. EO's stability for the sample with the solvent benzene:CS(99:1), comparing result of next-day analysis to same-day was 96.81% after desorption was 95.69% These results were in accordance with the less than 5% given by OSHA methoc 50. In conclusion, when pre-treatment of the EO in the HBr=coated charcoal, analyzing immediately after desorption by DMF is more simple, precise, and efficient than other analyzing methods, and the stabiity of the sample 24 hours after desorption was alst established.