개별요소법에 의한 보강토옹벽의 안정해석

황정규,김화주 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

The use of geosynthetics as a reinforcing element for reinforced earth retaining structures has been recently increased in view of its low cost, light weight and good durability. With fabrics, however, large strains may frequently be induced, it is essential, therefore, to assess the strains likely to be induced. In this paper an analytical procedure based on Chang's discrete element method for stability analysis of reinforced soil retaining wall is presented to predict displacements of geosynthetics. For the stability analysis of geosynthetic reinforced soil retaining wall, nonlinear behavior of the reinforcement is simulated by using hyperbolic model. Furthermore, the maximum reinforcement tension in any reinforcement layer has been estimated by modifying the method proposed by Duncan et al.(1980,1986), Ehrlich & Mitchell(1994)

장기투석을 받은 만성 신부전 환자에서 발생한 종양에 관한 고찰

황정화,이혜경,홍현숙,박재성,김대호,권귀향,최득린,황승덕,이희발 순천향의학연구소 1996 Journal of Soonchunhyang Medical Science Vol.2 No.2

The authors tried to evaluate tumor occurrence in long-term dialysis patients with chronic renal failure. Among 359 patients, 20 patients (about 5.6%) were diagnosed with malignancy during long-term dialysis from the period of 1983 to 1995 at our nephrology department. The ultrasonographic and computed tomographic findings including the clinical features of 20 patients that were retrospectively reviewed. The mean age of the patients was 53 (37-75)years old and the ratio of male to female was 9:1. Among the 20 cases, 7 cases of hepatoma (35%) were developed. Among them, urinary tract tumors such as renal and bladder cancer were developed in 4 (20%) and 2 (10%) of the cases. Other malignant tumors were lymphoma, stomach cancer, uterine cervical cancer, cholangiocarcinoma, lung cancer, meningioma, and acoustic neuroma one case of each (each of 5.3%). The most common tumor in patients with chronic renal failure, who were receiving long-term dialysis, was hepatoma and the second most common tumor was cancer of the urinary tract such as kidney and bladder.

결핵균체 추출액으로부터 알파 및 베타단백항원의 정제에 관한 연구

황인택,백태현,김화중,박정규,최대경 충남대학교 의과대학 지역사회의학연구소 1990 충남의대잡지 Vol.17 No.1

It is well known that α- and β-antigens are major protein products of Mycobacterium tuberculosis. Alpha and beta antigens from the cell extract of Mycobacterium tuberculosis were purified by 80% ammonium sulfate precipitation, gel filtration of Sephacryl S-300, DEAE-Sephacel ion exchange chromatography and hydroxylapatite chromatography. Beta antigen was purified further by column preparative polyacrylamide gel electrophoresis. The purified alpha and beta antigens were checked degree of purified by SDS-polyacrylamide gel electrophoresis. The results were summarized as follows: 1. Alpha antigen was purified by ammonium sulfate precipitation, gel filtration, ion exchange chromatography and hydroxylapatite chromatography. The purified alpha antigen showed a distinct band of 30 KDa molecule on SDS-polyacrylamide gel electrophresis. 2. Beta antigen was purified by ammonium sulfate precipitation, gel filtration, ion-exchange chromatography, hydroxylapatite chromatography and column preparative polyacrylamide gel electophoresis. The purified beta antigen showed two distinct bands of 83 KDa and 52 KDa molecules on SDS-PAGE. 3. Especially, Beta antigen was absorbed well to hydroxylapatite column but alpha antigen was passed completely without absorption.

축구선수의 Detraining과 Retraining이 혈청지질 및 호르몬농도에 미치는 영향

정정화,박재현,채종훈,성혜련,황지인,윤미숙,노금선,윤종관,윤영학,노순덕,정경숙,박일규,김은희,박현태,박상갑 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

The purpose of this study was to investigate the effects of detraining and retraining on serum lipid and hormones in soccer players. Subjects were seven male high-school soccer players. V˙O_2max was determined for each subjects by administering a treadmill test(initial speed: 90m/min, grade: 5%, increasing speed per 3 min: 30m/min). Serum lipid(T-C, TG, HDL-C LDL-C) and hormones(epinephrine, norepinephrine, growth hormones, cortisol) were assayed pre and post detraining in 10, 20, 30 days after retraining. The repeated ANOVA was used to determine significant differences. The 0.05 level of significance was as critical level for the study. The results of the study were as follows: 1. V˙O_2max(ml/min) were 3576.3±204.2ml/min pre detraining, 3234.1±198.9 ml/min post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/min) were 3601.4±170.9 ml/min. There were significantly(p<.05) increased in retraining periods. 2. V˙O_2max(ml/kg/min) were significantly(p<.05) decreased from 62.3±2.9 ml/kg/min to 55.9±4.7 ml/kg/min in detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/kg/min) were 62.4±3.4ml/kg/min, 62.7±2.3ml.kg/min, 67.3±7.2ml/kg/min respectively. There were significantly(p<.05) increased in retraining periods. 3. T-C were significantly (p<.05) increased from 166.6±8.5mg/dl to 175.3±10.3 mg/dl in detraining. In 10, 20, 30 days after retraining, T-C were 160.1± 3.2mg/dl, 156.7±3.7mg/dl, 140.3±9.0mg/dl. There were significantly(p<.05) decreased in retraining periods. 4. HDL-C were 61.4±6.6mg/di pre detraining, 5.3±6.6mg/dl post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, HDL-C were 56.9±7.1mg/dl, 56.4±9.2mg/dl, 57.7±9.1mg/dl respectively. There were no significant difference in retraining periods. 5. The hormones(epinephrine. norepinephrine, growth hormone, cortisol) were changed as same patterns. Epinephrine were 26.0±7.0[g/ml pre detraining, 24.6±3.2pg/ml post detraining. In 10, 20, 30 days after retraining, epinephrine were 26.9±5.6pg/ml, 30.6±6.2pg/ml, 29.4±5.6pg/ml respectively. There were no significant difference in retraining periods. In conclusion, HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were decreased, T-C, LDL-C and TG were increased in detraining. But HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were increased, T-C, LDL-C and TG were decreased in retraining.

에탄올-물 혼합용매내에서 2,4,6,N-Tetramethyl Pyridinium Iodide의 회합에 대한 압력효과

黃正儀,池鍾基,李永華,禹義夏 慶北大學校 物理化學硏究所 1984 硏究論文集 Vol.5 No.-

부피 퍼센트 95%의 에탄올-물 혼합용매내에서 2,4,6,N-테트라메틸 피리디늄요오드(TeMPI)의 이온회합 상수(K)를 수정한 자외선분광 및 전기 전도도 혼용법으로 온도범위 25∼50℃, 압력범위 1∼2,000bars에서 결정하였다. K값은 압력이 증가함에 따라서 증가하였고 40℃에서 최대값을 나타내었다. 부분몰부피변화(ΔV)는 비교적 작은 음의 값이 었으며 ΔV의 절대값은 40℃에서 최소값을 보여주었다. TeMPI의 이온 크기 변수(a)는 40℃에서 최대값을 가졌다. ΔH˚값은 40, 25℃ 그리고 50℃에서 각각 영, 음수 및 양수로 나타났으며 엔트로피(ΔS˚)와 자유에너지(ΔG˚)와 같은 다른 열역학변수 값도 계산하였다. 이와 같은 실험결과로부터 우리들은 TeMPI가 압력증가에 대하여 안정화되고, 40℃까지는 온도증가에 따라서도 안정화됨을 보여주었다. 그러나 40℃에서는 TeMPI 두 분자에 있는 8개 메틸기의 분자간 소수성 상호작용으로 인하여 약한 이량체를 형성하고 50℃ 이상에서는 다시 열적으로 분해된다는 결론을 얻게 되었다. The ionic association constants(K) of 2,4,6,N-tetramethyl pyridinium iodide(TeMPI) in 95 volume percentage ethanol-water mixture were determined by a modified UV and conductance method at 25℃ to 50℃ under 1 to 2,000 bars. The K values increase with increasing pressure and have maximum value at 40℃. The partial molar volume change (ΔV) has relatively small negative value and the absolute values of Δ are minimum at 40℃. The ion size parameter(a) of TeMPI have maximum value at 40℃. ΔH˚ values are zero, positive and negative at 40℃, 25℃ and 50℃ respectively. Other thermodynamic parameters such as the changes of standard entropy (ΔS˚) and free energy(ΔG˚) were evaluated. From these experimental results, we came to conclusion that TeMPI is stabilized by the elevation of pressure and that of temperature below 40℃ but weakly dimerized at 40℃ because of the intermolecular hydrophobic interaction of eight methyl groups of two molecules. And it thermally decomposed above 50℃.

2차원적 불순물 재 분포에 관한 공정 Simulator 개발

황호정,박화식 중앙대학교 기술과학연구소 1989 기술과학연구소 논문집 Vol.19 No.-

This paper presents an investigation of numeric approaches to efficient solution of diffusion equation describing the two-dimensional impurity redistribution phenomena in semiconductor during thermal oxidation. The numerical method to solve the two-dimensional moving boundary problems ueses boundary element techniques which based on Green's function.

肢발생중 세포 증식성에 미치는 Etretinate의 영향에 관한 연구

황정연,김은영,박선화,전용혁 고려대학교 의과대학 1994 고려대 의대 잡지 Vol.31 No.1

Cell proliferation in the developmental sequence of fore-limb in the DDY mouse with the adverse effect of single dose of etretinate (Tigason®) on it correlated to the drug-induced dysmorphogenesis was studied by measns of argyrophil technique for nucleolar organizer regions(AgNORs) and expression of proliferating cell nuclear antigen(PCNA). The number of AgNORs per nucleus displayed regional differences in the limb bud on day 11 of gestation, as higher values in apical ectodermal ridge(AER) and growing tip but decreased rapidly thereafter compared with those in the other parts of epithelia and subepithelial mesenchyme, while in core mesenchyme where the higest in its value on day 11, the numbers decreased depend not on the age but on the chondrified stage specific. Antibody reaction to PCNA expressed in almost all of the cells, stronger in mesenchyme than in epithelia on day 11 and then decreased gradually with the development proceed. Siver reactions to NORs as well as PCNA expression were decreased sharply by etretinate but recovered gradually from 24 hours after treatment except the value of AgNORs in the chondrified mesenchyme. The results Indicate that growth conducted by AER with subridge mesenchyme and chondrification in the core mesenchyme are two of major processes in the early development of limb, and the adverse effects of etretinate on proliferation and differentiation persist longer in the chondrified area but decreased expression of proliferative activities by the drug do not appear to be the result subsequent to the drug-induced cell death. The results suggest that temporal inhibition or interruption of the proliferation could deprive the programmed sequence of development of its appropriate timing with subsequent disturbance of the pace in growth which might be a role of limb dysmorphogensis but the drug's affinity to the chondrified cells remains a question.

Multiple schwannomas : a case report 증례 보고

황정화 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

20세 여자가 건강 검진에서 우연히 발견된 종격동 종괴에 대한 정밀 검사를 위해 내원하였다. 과거력 상 약 3-4년 전 신체 여러 부위에 촉지되는 종괴에 대한 세침 흡입술 (fine needle aspiration)을 시행한 결과 양성 연부 조직 종양 소견을 보였다. 본 환자에서 신경섬유종증 (neurofibromatosis) 1형 및 2형에 대한 임상력 징후 및 가족력은 보이지 않았다. 입원 후 시행한 뇌 자기공명영상 (brain MRI) 상 청각신경집종 (vestibular schwannoma) 및 다른 뇌종양 소견은 보이지 않았다. 척추 자기공명영상 (spinal MRI) 상 경부 경동맥 공간 (carotid space) 및 배부 근육 층에서 각각 2개의 종양이 발견되었으며, 촉지되는 연부 조직 종괴 및 종격동 종괴를 규명하기 위하여 시행한 발목 자기공명영상 (ankle MRI) 및 흉부 전산화 단층 촬영 (chest CT) 상, 내측 복사 (medial malleolus) 및 어깨 주위의 피하부 (subcutaneous area)에 연주 조직 종양을 보였으며 심장에 인접하여 전 종격동 종양이 발견되었다. 이들 5개의 종양은 모두 신체의 오른쪽에 국한되어 있었다. 어깨 주위의 피하부, 내측 복사부 및 전 종격동 종양을 외과적 수술을 통해 제거하였으며 이들 종양은 모두 신경집종 (schwannoma)에 합당한 병리 조직 소견을 보였다. 신경집종증 (schwannomatosis)은 대부분 산발적으로 (sporadic) 발생하는 것으로 보인다. 신경집종증은 성인에서 각각 다른 해부학적 위치에 2개 이상의 신경집종이 있으며 임상 소견 및 방사선 소견상 신경섬유종증 2형에 해당하는 어떠한 징후도 보이지 않는 경우에 지칭 할 수 있을 것으로 보인다.

OFDM 수신기를 위한 채널 등화 알고리즘

위정화,황유모 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

In this paper, we propose 1-tap ACDFE(Additional Coefficient DFE) channel equalization algorithm which use the frequency domain DFE(Decision Feedback Equalization) with additional coefficients and confirm its performance in applying minimum mean-square error(MMSE) criterion. It is confirmed by computer simulations that the proposed ACDFE has better performance than the conventional DFE in terms of SER and MSE. The ACDFE has advantages which are the speed of convergence and robust operation in Doppler shift by additional coefficient which is independent of subcarrier.

치과병원 진료실 내에서 메티실린 또는 반코마이신 저항성 Staphylococcus aureus의 검출

민정희,박순낭,황호길,민정범,김화숙,국중기 대한치과보존학회 2007 Restorative Dentistry & Endodontics Vol.32 No.2

본 연구는 조선대학교 치과병원의 진료환경 및 진료요원으로부터 기회감염성 병원체로 알려진 methicillin 또는 vancomycin 저항성 황색포도상 구균 (methicillin- or vancomycin-resistant Staphylococcus aureus: MRSA or VRSA)의 존재 여부를 조사하여, 이를 광주지역 개원치과와 비교분석을 통해 현재 조선대학교 치과병원의 MRSA와 VRSA의 오염정도를 파악하고자 하였다. 이를 위해 진료실 환경 및 진료요원으로부터 분리한 S. aureus 균주들의 8종 항생제에 대한 감수성 조사를 시행하고, 기존에 알려진 항생제 내성 유전자 존재 여부를 PCR법을 이용하여 확인하였다. 그 결과, 조선대학교 치과병원의 진료요원에서 채취한 샘플 중 1개 (2.3%), 개원 치과에서는 2명 (10%)의 진료요원의 샘플에서 S. aureus가 분리되었으며, 진료환경에서는 두 곳 모두에서 S. aureus가 검출되지 않았다. 조선대학교 치과병원과 개원치과에서 분리된 S. aureus는 amoxicillin, penicillin G, ciprofloxacin, clindamycin, vancomycin에 내성을 보이며, oxacillin, cefuroxime에는 균주에 따라 감수성 또는 내성을 보였다. 조선대학교 치과병원에서 분리 된 S. aureus는 erythromycin과 clindamycin에 내성 유전자인 ermA가 존재 하였으며, 개원치과에서 분리된 3개의 S. aureus 중 2개에서 penicillin과 oxacillin에 내성 유전자 mecA가 존재하는 것으로 나타났다. Vancomycin 내성 유전자인 vanA, vanB는 어떠한 샘플에서도 검출되지 않았다. 이상의 결과를 종합할 때, 본 연구는 조선대학교 치과병원과 개원치과의 S. aurues 분포 및 MRSA 또는 VRSA의 존재여부를 조사하여 MRSA와 VRSA의 확산예방을 위한 치과진료 환경의 개선과 적절한 항생제 사용에 대한 기초 자료를 제공할 것으로 사료된다. The purpose of this study was to obtain the basic information for the improvement of dental environment by investigating the presence of methicillin- or vancomycin-resistant Staphylococcus aureus (MRSA or VRSA) isolated from dental health care workers (DHCWs) and environment of the Chosun University Dental Hospital (CUDH) and a private dental clinic (control group). Staphylococcus aureus (S. aureus) was isolated from anterior nares of 42 DHCWs and 38 sites, unit chairs, x-ray devices, computers, etc., at 10 departments of the CUDH and 20 DHCWs and 11 sites at the private dental clinic. S. aureus was isolated on mannitol salt agar plate and confirmed by PCR with S. aureus species-specific primer. Antimicrobial susceptibility test of clinical isolates of S. aureus against several antibiotics including methicillin (oxacillin) was performed by investigating minimum inhibitory concentration (MIC) using broth microdilution assay. In addition, PCR was performed to detect the methicillin- or vancomycin-resistant gene. The data showed that one strain of S. aureus was isolated from DHCWs of the CUDH and three strains of S. aureus was isolated from 3 samples of the private dental clinic, respectively. All of the isolates from the CUDH and the private dental clinic had resistance to penicillin G, amoxicillin and vancomycin and susceptibility to oxacillin and ciprofloxacin. The S. aureus strains were already obtained the resistance to penicillin G and amoxicillin. These results suggest that two dental clinics were under relatively safe environment.