우리회사소개-신한쥬얼테크(주)

이경석,Lee, Gyeong-Seok (사)한국원적외선협회 2003 한국원적외선협회보 Vol.18 No.-

요통 및 좌골신경통 환자의 치료결과 : 수면장애 및 피로감과 자각적 통증 및 장애정도의 관계

이경석,윤석만,도재원,배학근,윤일규,Lee, Kyeong-Seok,Yoon, Seok-Mann,Doh, Jae-Won,Bae, Hack-Gun 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.3

Objective : Psychological factors may have a major influence on the outcome of treatment for back pain. We investigated the relationship between the outcome and some psychological factors, such as self-reported pain intensity, disability, sleep disturbance and fatigue. Method : The study was conducted as a survey using a questionnaire and telephone interviews. The survey included consecutive 294 patients who visited the neurosurgical out-patient department complaining of low back pain and contacted by telephone on average seven months after the first visit. Pain intensity was measured by visual analog scale, and disability was assessed by Waddell's chronic disability index. Results : The outcome of treatment for back pain was recovered in 36.7%, improved in 30.6%, almost same in 28.6%, and aggravated in 4.1%. Overall rate of improvement was 67.3%. The rate of improvement was related to the duration, patterns and intensity of the symptom, and Waddell index. It was not influenced by the doctors, special studies, and methods of treatment. When the duration was more than 6 months, there were the symptoms of both back and legs, and the self-reported Waddell index was 1-3, the rate of improvement was relatively low. Although the intensity of the pain and disability was closely related to the degree of sleep disturbance, fatigue, appetite, or indigestion, the outcome of treatment for back pain was not always bad in patients with high psychological stress. Actually the outcome of the patients who complained severe pain and disability was better than the outcome of the others. Conclusion : The outcome of the back pain can be predicted by the duration, patterns and intensity of the symptom, and Waddell index. The multidisciplinary treatment will be necessary for the patients whose expected outcome is not good to reduce not only the physical symptoms but also the psychological stress.

남은 음식물의 중온발효 시료화에 대한 공기의 영향

이경석,김소영,오창석,이기영,Lee, Kyung-Seok,Kim, So-Young,Oh, Chang-Seok,Lee, Ki-Young 유기성자원학회 2003 유기물자원화 Vol.11 No.1

본 연구는 남은 음식물을 유산균을 이용하여 발효 사료화 하기 위해 실시하였다. 발효를 촉진시키기 위한 균주로는 Lactobacillus acidophilus를 사용하였고 최적의 발효조건을 갖는 공기 주입량을 알아보기 위해 시료의 발효 조건을 각각 달리 하였다. 시료는 교반하지 않고 공기주입 또한 없는 혐기적 조건의 것과 50rpm의 속도로 교반하면서 0.25v.v.m의 공기를 주입한군, 70rpm의 속도로 교반하면서 0.5v.v.m의 공기를 주입한 군으로 나누었다. 시료는 모두 $37^{\circ}C$로 유지하면서 48시간 발효 시키며 12시간 단위로 시료를 채취하였다. p.H와 유기산함량, 환원당함량과 유산균수를 측정하여 남은 음식물을 발효시키기 위한 최적의 공기 주입량을 알아보았다. 실험결과 50rpm 0.25v.v.m에서 가장 낮은 p.H를 보여주었고 유기산 함량과 환원당 함량은 70rpm 0.5v.v.m에서 가장 높은 함량을 보였다. 유산균은 50rpm 0.25v.v.m에서 가장 많은 증식되었음을 보여주어 적절한 공기의 주입이 남은 음식물의 발효를 촉진하는 것으로 보여진다.

I 형 축력부재의 잔류응력 패턴과 최대 잔류 응력을 고려한 접선탄성계수식

이경석,김승준,최진희,강영종,Lee,Kyung-Suk,Kim,Seung-Jun,Choi,Jin-Hee,Kang,Young-Jong 한국방재학회 2011 한국방재학회논문집 Vol.11 No.5

보 요소를 사용한 비선형 해석법에는 크게 소성영역법과 탄소성 힌지법, 그리고 개선소성힌지법이 있다. 그 중, 적은 계산량과 단면의 비탄성화의 진전을 고려 할 수 있는 개선 소성 힌지법은 현재 많은 연구자들에 의해 사용되고 있으며, 특히 축력 작용 시 잔류응력으로 인하여 단면이 점진적으로 소성화 되는 과정이 CRC 접선탄성계수로 표현되어 사용되고 있다. 하지만 기존의 식은 최대압축잔류응력을 항복응력의 50%로 가정하고 제한된 형태의 잔류응력 패턴에 대해 국한된 식이므로, I 형 단면의 재료 비선형해석에 대한 적용성에 한계가 있고 이는 유한요소해석 프로그램을 이용하여 기존식의 한계를 확인할 수 있었다. 본 연구에서는 새로운 접선 탄성계수식이 유도되었는데 이 식은 많은 연구자가 다루는 주요한 잔류응력 패턴, 최대 잔류응력의 크기, 단면의 형상 및 하중의 방향을 모두 고려할 수 있는 형태로 유도되었다. 유도된 식은 ABAQUS V6.9를 이용한 비탄성 해석을 통해 검증되었다. This paper suggests a reasonable tangential modulus equation of a steel I-section member subjected the axial force considering residual stress. In general, there are three analyses methods which can be used to inelastic analysis using a beam element, a plastic zone analysis, an elastic-plastic hinge analysis, and a refined plastic hinge analysis. Among these three analysis methods, a refined plastic hinge analysis has been performed by many researchers because of its efficiency as well as reasonability. In a refined plastic hinge analysis, the CRC tangential modulus equation is adopted to consider a gradual yielding effect when the member is applied the axial force. But, this CRC tangential modulus equation can consider only restricted residual stress pattern and maximum value of the residual stress which is a half of a yield stress. By inelastic finite element analysis in this research, this limitation of the CRC tangential modulus revealed. In this research, new tangential modulus equation of a steel I-section member subjected the axial force was derived. This equation can consider different residual stress patterns, maximum value of the residual stress, the geometry of the section, and the direction of applied axial force. And this equation is validated by the inelastic finite element analysis using ABAQUS V6.9.

The Utility of Fibrin Sealant and Safety of Thyroid Surgery without Drainage

이경석,윤진,김문준,양윤수,홍기환,Lee, Kyeng-Suk,Youn, Jin,Kim, Mun-Jun,Yang, Yun-Su,Hong, Ki-Hwan The Korean Society for Head and Neck Oncology 2012 대한두경부 종양학회지 Vol.28 No.1

배경 및 목적 : 섬유소 응고제(fibrin sealants)는 다양한 두경부수술에서 지혈목적으로 사용되고 있다. 본 연구의 목적은 배액관을 삽입하지 않는 갑상선 수술에서 섬유소 응고제의 효용성과 안정성을 알아보고자 하였다. 재료 및 방법 : 최근 1년간 108명의 갑상선 수술환자 중에서 수술 후 배액관의 삽입없이 수술을 받은 103명의 환자를 대상으로 하여 임상적인 특징을 분석하였다. 결과 : 103명의 대상환자 중에서 남성은 16예, 여성은 87예였다. 대상환자의 평균연령은 $46.7{\pm}13.0$세였고, 연령분포는 17세에서 72세였다. 갑상선 종물의 평균크기는 $2.08{\pm}1.61cm$였고, 종물의 크기는 최소 0.2cm에서 최대 10.0cm까지의 분포를 보였다. 수술에는 갑상선 엽절제술이 5예, 갑상선반절제술이 41예, 아갑상선 절제술이 8예, 갑상선 전절제술이 6예, 갑상선 전절제술과 중심경부림프절 절제술이 37예, 갑상선 전절제술과 선택적경부림프절 절제술이 6예가 있었다. 수술 후 합병증은 11예(10.6%)에서 발생하였고, 발생한 합병증으로는 장액성종창이 3예, 혈종이 1예, 일측성 성대마비가 3예, 저칼슘혈증이 4예 있었다. 성대마비는 수술 후 3개월 이내에 모두 호전되었고, 장액성 종창은 반복적인 세침흡인으로 호전되었다. 1예의 혈종은 지연성으로 발생하였고, 수술 후 5일째에 수술을 통해 제거하였다. 결론 : 이러한 결과에 근거하여 갑상선 수술에서 섬유소 응고제의 사용은 다양한 갑상선 수술에서 효과적인 지혈과 함께 안전하게 사용될 수 있으며, 배액관의 삽입을 감소시켜 줄 수 있을 것으로 생각된다.

방전플라즈마 소결법으로 제조된 Bismuth Antimony Telluride의 소결온도에 따른 열전특성

이경석,서성호,진상현,유봉영,정영근,Lee, Kyoung-Seok,Seo, Sung-Ho,Jin, Sang-Hyun,Yoo, Bong-Young,Jeong, Young-Keun 한국재료학회 2012 한국재료학회지 Vol.22 No.6

Bismuth antimony telluride (BiSbTe) thermoelectric materials were successfully prepared by a spark plasma sintering process. Crystalline BiSbTe ingots were crushed into small pieces and then attrition milled into fine powders of about 300 nm ~ 2${\mu}m$ size under argon gas. Spark plasma sintering was applied on the BiSbTe powders at 240, 320, and $380^{\circ}C$, respectively, under a pressure of 40 MPa in vacuum. The heating rate was $50^{\circ}C$/min and the holding time at the sintering temperature was 10 min. At all sintering temperatures, high density bulk BiSbTe was successfully obtained. The XRD patterns verify that all samples were well matched with the $Bi_{0.5}Sb_{1.5}Te_{3}$. Seebeck coefficient (S), electric conductivity (${\sigma}$) and thermal conductivity (k) were evaluated in a temperature range of $25{\sim}300^{\circ}C$. The thermoelectric properties of BiSbTe were evaluated by the thermoelectric figure of merit, ZT (ZT = $S^2{\sigma}T$/k). The grain size and electric conductivity of sintered BiSbTe increased as the sintering temperature increased but the thermal conductivity was similar at all sintering temperatures. Grain growth reduced the carrier concentration, because grain growth reduced the grain boundaries, which serve as acceptors. Meanwhile, the carrier mobility was greatly increased and the electric conductivity was also improved. Consequentially, the grains grew with increasing sintering temperature and the figure of merit was improved.

대한신경외과학회지에 발표된 요통 환자의 치료결과 평가방법

이경석,도재원,윤석만,배학근,윤일규,Lee, Kyeong-Seok,Doh, Jae-Won,Yoon, Seok-Man,Bae, Hack-Gun,Yun, Il-Gyu 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

Objectives : Criteria for evaluating the results of treating low back pain vary widely. We examined the methods measuring the outcome in the papers of Journal of Korean Neurosurgical Society. Methods : We selected all published articles describing the methods measuring the outcome of low back pain in the journal. They were classified into 3 periods such as period 1 for volume 1-20, 2 for volume 21-25, and 3 for volume 26-28. Results : There are 25 articles in period 1, 44 in period 2, and 30 in period 3. The outcome was classified into 0 to 5 classes by more than 15 different methods. Although the terms and descriptive criteria differ, 4 classes were the most common classification, being 16 in period 1, 39 in period 2, and 19 in period 3. The outcome was usually measured by authors' own method in period 1. In period 2, criteria by Gill et al was most commonly used along with many different criteria. Criteria by Prolo et al became a common method in period 3. Conclusion : Varying methods compromised comparative analyses of outcome. A more simple and universally applicable criteria is necessary to facilitate comparisons among various methods of treatment.

임의 위치 구조물의 손상예측을 위한 인공지능 기반 지진가속도 추정방법

이경석,서영득,백은림,Kyeong-Seok Lee,Young-Deuk Seo,Eun-Rim Baek 한국구조물진단유지관리공학회 2023 한국구조물진단유지관리공학회 논문집 Vol.27 No.3

It is not efficient to install a maintenance system that measures seismic acceleration and displacement on all bridges and buildings to evaluate the safety of structures after an earthquake occurs. In order to maintain this, an on-site investigation is conducted. Therefore, it takes a lot of time when the scope of the investigation is wide. As a result, secondary damage may occur, so it is necessary to predict the safety of individual structures quickly. The method of estimating earthquake damage of a structure includes a finite element analysis method using approved seismic information and a structural analysis model. Therefore, it is necessary to predict the seismic information generated at arbitrary location in order to quickly determine structure damage. In this study, methods to predict the ground response spectrum and acceleration time history at arbitrary location using linear estimation methods, and artificial neural network learning methods based on seismic observation data were proposed and their applicability was evaluated. In the case of the linear estimation method, the error was small when the locations of nearby observatories were gathered, but the error increased significantly when it was spread. In the case of the artificial neural network learning method, it could be estimated with a lower level of error under the same conditions.

외상성 추간판 손상과 의원성 척추장애인 만들기

이경석,도재원,윤석만,배학근,윤일규,Lee, Kyeong-Seok,Doh, Jae-Won,Yoon, Seok-Mann,Bae, Hack-Gun,Yun, Il-Gyu 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.7

Objective : Traumatic disc lesion is a lesion with tremendous controversies. The causal relationships of this lesion are not established along with pathogenesis, diagnostic criteria, methods of treatment and the outcome. However, a significant number of patients with back pain after a trauma underwent spinal operations under the diagnosis of traumatic disc lesions. Such an ill-directed operation eventually produce a person with an iatrogenic disability. We present two illustrative cases, and tried to make a preventive method. Methods : We examined the path from mild trauma after a road traffic accident into the iatrogenic disability in two illustrative cases, who requested disability assessment and medical appraisement. We evaluated the reason and background for such an unwanted outcome and tried to find a method to reduce or prevent it by a literature review. Results : These two patients were admitted to the hospital with the diagnosis of lumbar sprain after a road traffic accidents. They eventually underwent spinal surgery under another diagnosis such as traumatic disc herniation or internal disc disruption. They stayed at the hospital for more than six months and finally lost their jobs. They became the disabled at last. Although they complained back pain, they never insisted by themselves that their symptoms were due to the traumatic disc lesion. To prevent such an iatrogenic disability, the doctors should assist them to go-back to the workplace promptly instead of a reckless extension of the treatment period. It may be necessary to evaluate the certificates to extend the treatment period with an additional diagnosis by a medical expert. To reduce the unnecessary long-term admission, a new billing system such as a partial share for the high cost of the treatment by the patients may be needed. Conclusion : It is not the patient but the doctors, who has the responsibility to avoid the unnecessary operations. All treating doctors should try to reduce or prevent such an iatrogenic complication caused by ourselves before we are forced to do so.

국제학술회의 참관기 - 1999년 국제 신경손상 최신발전 학술회의

이경석,Lee, Gyeong-Seok 한국과학기술단체총연합회 2000 과학과 기술 Vol.33 No.2

지난 11월 20일부터 타이완의 타이베이시에서 열린 1999년 국제 신경손상 최신발전 학술회의는 전 세계 35개국에서 신경손상학에 관심이 있는 의사, 간호사, 그리고 학자 등 4백명에 가까운 과학자들이 모인 가운데 열렸다. '신경손상의 예방과 조절'이라는 주제로 열린 이번 학술회의에서는 특강과 토론, 그리고 자유연제와 포스터를 포함하여 모두 2백50여편의 논문이 발표되었다. 필자는 토론의 초청연자로 강의를 하고, 학회연회에서는 인사말을 발표하고 공동 좌장을 맡아 회의를 진행하기도 했다.