강중비금속소재물의 자동측정에 관한 고찰

김기철,김재남,박세열,윤의박 대한금속재료학회(대한금속학회) 1984 대한금속·재료학회지 Vol.22 No.3

In determining non-metallic inclusion rating in steel, the efficiency and reliability of conventional manual method and computer aided automatic method using image analyzer have been investigated. To see the effect of shape change of the inclusions on the cleanliness value based on existing test standards, the test coupons examined were taken from continuously casted slab, hot rolled plate and from cold rolled sheet where some inclusions were extremely elongated. Results show that the cleanliness values determined by two methods agree fairly well for both samples with globular oxide inclusions and with properly elongated inclusions. For samples with extremely elongated inclusions, however, the cleanliness value processed by image analyzer tends to be smaller than that of manual count. It appears that the automatic method gives faster and more reliable cleanliness value since the image analyzer determines the value in area fraction instead of in point fraction.

질적 연구다운 질적 연구를 위한 반성적 고찰

김기철 한국스포츠교육학회 2009 우리체육 Vol.- No.3

초등학교에서 도전활동과 경쟁활동 영역의 적용 방안

김기철 한국스포츠교육학회 2008 우리체육 Vol.- No.2

정상 배란주기에서 혈중호르몬농도 및 질식 초음파단층촬영에 의한 난포 크기의 변화양상 및 상호관계에 관한 연구

김기철,은길상,김석현,김정구,문신용,이진용,장윤석 대한산부인과학회 1990 대한산부인과학회 학술대회 Vol.66 No.-

해양구조용강 용접부의 염수부식에 관한 연구

김기철,이종봉,윤승열 ( K . C . Kim,J . B . Lee,S . R . Yoon ) 한국부식방식학회 1983 Corrosion Science and Technology Vol.12 No.3

소화성궤양에 있어서의 Cimetidine 과 Ranitidine 의 치료효과에 대한 임상연구

김기철,김승원,이영민,이성환,김석필,송치명 대한내과학회 1986 대한내과학회지 Vol.30 No.5

As to the treatment of peptic ulcer, this study was made to compare the clinical effectiveness between ranitidine and cimetidine which are compounded H₂-receptor antagonist. Patients were examined regularly to insure clinical effectiveness with a total of 75 cases of peptic ulcer(gastric ulcer 32 cases, duodenal 43 cases) They were diagnosed to have peptic ulcer by gastroduodenoscopy at the endoscopic room of Seoul Red-Cross Hospital, during 2 years from January 1984 to December 1985. Our study divided the patients into two groups, one with gastric ulcer and the other with duodenal ulcer. At random, these groups were divided into two more groups. One of these random groups was treated, with cimetidine, the other with ranitidine. To the cimetidine group, cimetidine was given in a dosage of 1,000-mg orally a day (200-mg three times and 400-mg at bedtime), and to the ranitidine group, ranitidine was given in a dosage of 150-mg orally twice a day. Thus, our results were obtained. Those in our studies were observed after treatment of four weeks, six weeks, and eight weeks by gastroduodenoscopy. 1) The male to female ratio of gastric ulcer was about 5.4 : 1, duodenal ulcer was about 3.3: l. So, males were predominent in both ulcers, and the most prevalent age group was those in their fifth decade of life having gastric ulcer, fourth decade of life having gastric ulcer, fourth decade of life in duodenal ulcer. 2) The location of the gastric ulcers were 15 cases in angle, 10 cases in antrum, and 7 cases in body. For duodenal ulcer were 36 cases in bulb, and 7 cases in pyloric area. 3) As to the subjective symptoms caused by gastric ulcers, the order was epigastric pain, hunger pain, abdominal bloating sensation, nausea and vomiting, and dyspepsia. These were also the same symptoms in duodenal ulcer. The improvement of symptoms were in the same or1er on both sides. The symptoms were relieved after 1 week of treatment in 66 777.2% of the cases, after 2 weeks of treatment in 82,486.6% of the cases, after 4 weeks of treatment in all cases. 4) The cumulative rates of complete healing of the ranitidine group having gastric ulcer goes as follows. Out of 15 subjects, 73%(11 cases) were healed after 4 weeks, 86%'(12 cases) were after 6 weeks and all were completely relieved after 8 weeks of treatment. Those of the cimeditine group consisted of 17 subjects, 65%(11 cases) were healed after 4 weeks, 80%(12 cases) after 6 weeks, 93%(13 cases) were relieved after 8 weeks of treatment. Those of the ranitidine group having duodenal ulcer consisted of about 21 subjects, 81%(17 cases) were healed after 4 weeks, 90%(18 cases) after 6 weeks of treatment. Those of the cimetidine group about 22 subjects, 68% (15cases) were healed after 4 weeks, 89% (16 cases) after 6 weeks and all were completely relieved after 8 weeks of treatment. 5) The untoward side effects were not founded in the use of these drugs except for 2 cases of the cimetidine group. The side effects were dizziness, headache and nausea. No abnormal findings were observed in the physical examination and in laboratory data. Finally, the conclusion of the above-stated is that ranitidine was considered an effective and a safe drug in the treatment of peptic ulcer disease the same cimetidine.

서울시립대학교 반도체공학과

김기철 대한전자공학회 1994 CAD 및 VLSI 설계연구회지 Vol.3 No.2

The Role of Arthroscopy of Acute and Chronic Painful Thumb Metacarpophalangeal Joint

김기철,신용은,김종필 대한수부외과학회 2016 대한수부외과학회지 Vol.21 No.2

Purpose: There has been few published on arthroscopy of metacarpophalangeal joint (MCPJ) despite increasingly being used worldwide. The purpose of this study was to investigate the effectiveness of arthroscopy for pathologies around MCPJ of the thumb. Methods: Between September 2007 and June 2015, 56 patients (56 thumb) who underwent arthroscopy of the MCPJ were retrospectively studied. Preoperative diagnoses, which were made through physical examination, plain radiograph, stress radiography, ultrasound, and magnetic resonance images (MRI), were compared with arthroscopic findings. Therapeutic arthroscopic surgeries were performed according to the needs of each patient. Functional outcomes were assessed with physical examination as well as disabilities of the arm, shoulder and hand (DASH) score and Michigan Hand outcomes Questionnaire (MHQ) score at an average 7.3 months follow-up. Results: Six patients who suspected with collateral ligament injuries in MRI confirmed different diagnoses under arthroscopy. At final follow-up, the mean range of flexion contracture of the MCPJ was 5°, and the mean range of further flexion was 52.7°. Grip and pinch strength averaged 87.2% and 79.3% of contralateral side. Mean DASH and MHQ score were improved from 48.1 and 44.6, preoperatively to 14.9 and 26.3, postoperatively (p<0.001, p=0.012, respectively). All patients were satisfied with their outcomes at final follow-up, except 4 patients who noted joint stiffness or chronic pain around the thumb. Conclusion: Our results revealed that arthroscopy is helpful for both diagnostic and therapeutic purposes of acute and chronic painful MCPJ of the thumb. However, further studies are needed to expand the applications of arthroscopy of MCPJ of the thumb.

5. 레이저 용접기술의 개요와 산업 적용 현황 - 자동차, 철강, 전자 관련 산업 수요 커 부품산업 다양화, 정밀도에 대처가능

김기철 한국광학기기산업협회 2001 光學世界 Vol.13 No.2

레이저 용접은 매우 작은 점으로 집속된 높은 밀도의 에너지로 재료를 용융시키는 용접방법으로, 좁고 깊은 용접부를 얻을 수 있으며 출력만 충분하면 단 1회의 용접으로도 상당히 깊은 용접부를 쉽게 얻는다는 장점이 있다. 레이저 용접의 원리와 특징, 레이저 용접 공정 변수, 레이저 용접공정의 관리, 산업현장에서의 레이저 용접기술 적용 현황을 알아본다.

바닥판 구조물의 진동제어를 위한 MR 감쇠기의 적용

김기철,곽철승,Kim, Gee-Cheol,Kwak, Chul-Seung 한국공간구조학회 2006 한국공간구조학회지 Vol.6 No.3

수동동조질량감쇠기의 진동제어 효과는 질량감쇠기와 구조물과의 동조로 인하여 나타나고 있다. 그러나 바닥판 구조물의 질량과 강성의 변화로 인하여 실제 구조물에 있어서 비동조 현상이 일어나기도 한다. 이러한 상황에서는 수동동조질량감쇠기의 성능이 비효율적이며 경우에 따라서는 구조물의 진동을 증가시키기도 한다. 본 논문에서는 기계나 사람에 의한 바닥판 구조물의 진동을 줄이기 위하여 자기유체감쇠기의 적용성을 알아보고자 한다. 준 능동제어와 groundhook 제어 알고리즘을 적용하여 준능동감쇠기의 성능과 수동질량감쇠기의 성능을 비교 분석하였다. 또한 비동조 상황에서의 준능동감쇠가와 수동질량감쇠기의 견인성을 비교 분석하여 다음과 같은 결론을 얻었다. 자기유체감쇠기는 동조상황에서 우수한 제어 성능을 가지고 있으며 비동조 상황에서도 우수한 견인성을 보여주고 있다. A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. when TMDs are offtuned, TMDs their effectiveness is sharply reduced. Moreover, the off-tuned nTMDs can excessively amplify the vibration levels of the primary structures. This paper discusses the application of a new class of MR damper, for the reduction of floor vibrations due to machine and human movements. The STMD introduced uses a MR damper called to semi-active damper to achieve reduction in the floor vibration. Here, the STMD and the groundhook algorithm are applied to a single degree of freedom system representative of building floors. The performance or the STMD is compared to that or the equivalent passive TMD. In addition, the effects of off-tuning due to variations in the mass of the floor system. Comparison of the results demonstrates the efficiency and robustness or STMD with respect to equivalent TMD.