660kW급 풍력발전기 로터의 강제 응답 해석에 관한 연구

정순철,김덕수,이재응 중앙대학교 기술과학연구소 2001 기술과학연구소 논문집 Vol.31 No.-

본 연구에서는 660㎾급 풍력발전 시스템용 유도발전기 로터의 강제 응답 해석을 수행하였다. 이를 위하여 유한요소법을 이용한 회전체 시스템의 모드 해석을 수행하였으며, 모드 실험 결과 나타난 고유진동수와 모드 형상의 오차를 줄이기 위하여 유한요소 모델의 구조 변경을 수행하였다. 또한 회전체 시스템의 안정성 해석을 위하여 로터에 작용하는 여러 가지 외력(불평형력, 전자기력등)에 대한 강제 응답 해석을 수행하였다. 그 결과 공진주파수는 운전주파수인 30㎐(1800rpm)의 약 4.5배의 크기에서 발생하였으며, 운전주파수에서의 최대 처짐은 풍력발전기 회전체 시스템의 자중에 의한 정적 처짐과 공극에 비하면 매우 미소하여 거의 무시할 만 하다. 따라서 로터에 작용하는 외력은 시스템의 안정성 큰 영향을 미치지 않는 것이라 결론 지을 수 있다. In this paper, the stability analysis of the rotor system in the wind-power generator was performed by using Finite Element Method. Experimental modal analysis of generator rotor system was performed and the result were used to update the finite element model. The stability analysis of wind-power generator rotor-bearing system was performed through harmonic analysis with all possible external forces including the electromagnetic force, the unbalance force, the torsional force, etc. As a result of stability analysis, the first natural frequency of the bearing-rotor system is 4.5 times as large as operating frequency. The dynamic deflection at operating frequency is quite smaller than static deflection which is also quite smaller than the air-gap. So it can be concluded that the external forces of the rotor have no effect on stability of the rotor-bearing system.

신체형장애 환자에서의 좌우의 통각예민도 비교

이덕기,서일석,김명정 大韓神經精神醫學會 1991 신경정신의학 Vol.30 No.1

The authors measured pain sensitivity in right and left fingers in 30 patients with somatoform disorder, 30 patients with other neuroses and 30 normal controls. The pain sensitivity was measured by giving a 3 pound weight on the dorsum of a finger for ten seconds and then letting the subject rate the subjective pain on the modified Visual Analogue Scale. Pain sensitivity of left fingers in patients with somatoform disorder was 6.92±2.09cm, a significantly higher value compared to 5.82±2.30cm of the right counterpart. And this left-right difference was not seen in the control groups. From these findings, the authors support the hypothesis that in the somatoform disorder, the left side is more sensitive than the right side in pain sensitivity and this phenomenon is not seen in other neuroses and normal controls.

터널링 캐리어에 의한 질화, 재산화된 모스 소자의 전기적 특성

이정석,장창덕,이용재 東義大學校産業技術開發硏究所 1998 産業技術硏究誌 Vol.12 No.-

The main objections of this research are to investigate the electrical properties of ultra-thin nitrided oxide(NO) and reoxidized nitrided oxide(ONO) films that are considered to be promising candidates for replacing conventional silicon dioxide film in ULSI level integration. In this paper, we studied I-V characteristics due to F-N tunneling, leakage current, and time-dependent dielectric breakdown(TDDB) of thin layer SiO₂, No and ONO prepared by rapid thermal processing (RTP) to prevent the redistribution of impurities in the MOS devices. From the measurement results, we can know that nitrided oxides(NO) film have the worse electric characteristics than reoxided nitrided oxides(ONO), ONO film shows superior dielectric characteristics, leakage current, and breakdown-to-charge (Q??) performance to the NO film, while maintaining a similar electric field strength compared to NO layer.

전신마취하에서 유치 조기발거시 간격유지장치의 설계 및 장착에 대한 증례보고

이상호,정문용,이창섭,강덕일 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.3

Space maintainers needs following extraction of primary molars, due to severe dental caries under general anesthesia. Delivery of conventional space maintainers has three of the disadvantages of the method, there being a impression taking and time consuming due to laboratory procedure, and delivery problem due to relaxed tongue. For this problem improved, modified space maintainer is prefabricated before procedure, and adjust, delivery in operation room, favorable results were obtained. The following results were obtained. 1. Delivery time is very reduced than conventional space maintainers. 2. After space maintainer delivery, follow check-up, without impingement of soft tissue, distortion of wire. After space maintainer delivery, continuous research is required so that space maintainer delivery is applied to usual dental treatment, and it is necessary of long term research.

중증 근무력증 52례에 대한 임상적 고찰

박건주,하정상,이준,도현철,박승권,서상덕,기병수,김진국 영남대학교 의과대학 1996 Yeungnam University Journal of Medicine Vol.13 No.1

1985년 8월부터 1996년 1월까지 중증근무력증으로 진단받은 환자 52례에 대한 임상적 고찰을 통하여 다음과 같은 결론을 얻었다. 1. 전체 환자 중 남자가 19례(35.8%), 여자가 33례(64.2%)이넜고 11세에서 20세 사이가 12례(23%)로 가장 높은 빈도를 보였다. 2. 환자의 초기증상으로는 안검하수, 복시 등의 안구증상이 37례(71.2%)로 가장 많았고 modified Osserman의 분류에 따라서도 가장 증상이 가볍고 약물치료에 잘 반응하는 1군이 36례(69.3%)로 가장 많았다. 3. 환자가 호소하는 증상의 비특이성과 회복과 재발을 거듭하는 질병의 특성으로 인해 발병이후 진단될 때까지의 시간은 비교적 오래 걸렸고 1년이상 경과하며 진단된 경우도 16례(30.8%)나 되었다. 4. 자가면역질환이 7.6%에서 동반되었는데 갑상선기능 항진증이 2례(3.8), 인슐린의존형 당뇨 2례(3.8%)였고 종격동 전산화 단층촬영소견에서 흉선의 비대가 의심되었던 환자는 6례(11.5%), 흉선종이 발견 되었던 경우는 3례였다. 5. 환자의 치료는 대부분 항콜린에스테라제나 부신피질호르몬을 병용하는 내과적 치료를 하였으며 약물의 치료에 반응이 미비하거나 악화되는 경우 혹은 종격동 전산화 단층촬영상에서 흉선의 이상 소견이 보인 경우에 2례(3.9%)에서는 흉선절제술이, 1례(1.9%)에서는 혈장여과요법이 추가 되었고 흉선절제술과 혈장여과요법이 같이 병합 치료된 경우도 3례(5.9%)있었다. 6. 전체 환자중 2명에서 자연치유의 경과를 보였으며 이들은 모두 1군이였다. 그리고 흉선절제술과 부신피질 호르몬 투여로 완치된 예가 1례있었다. The authors experienced 52 patients with myasthenia gravis who were diagnosed at the Department of Neurology, Yeungnam University Hospital from August 1985 to January 1996. The following results were obtained through diagnostic evaluation and treatment. 1. The ratio of male to female was 1:1.7 and the most prevalent age group was second decade. 2. The most common initial presentation symptom was ocular(71.2%) and the peak incidence group was stage I(69.3%) according to the modified Osserman's classification. 3. In 16 patients(30.8%), it took more than a year to diagnose due to symptoms which were relapsed and remitting. 4. Of 52 patients, 2 cases were associated with thyroid disease(3.8%) and 2 with insulin-dependent diabetes mellitus(3.8%). 5. All of those who received anticholinesterase and corticosteroid therapy were improved with the exception of 5 cases which were improved after thymectomy and/or plasmapheresis. 6. Spontaneous remission was occured in 2 cases(3.8%) of ocular myasthenia gravis. And 1 case of group II was cured through thymectomy and long-term corticosteroid therapy.

Pendulum 장치의 상악대구치의 원심이동에 대한 효과

이창섭,김재광,강덕일,송광철,정현구,이상호 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.3

Ⅱ급 치성교합을 가진 환자에서는 I급 구치부 교합관계를 형성하기 위하여 상악 대구치의 원심이동이 필요하다 본 연구에서는 pendulum장치를 이용한 상악 대구치의 원심이동시 대구치의 이동양상과 고정원의 전방이동 및 정출정도 등 치아와 골격에 미치는 영향을 평가하기 위하여 시행되었다. 상악 제1대구치를 원심이동시켜 1급 구치관계가 형성된 19명의 환자 (남: 8명. 여: 11명, 평균연령 11.68±1.52세)에서 장치 장착 전과 장치제거 직후에 얻어진 측면두부방사선사진을 비교 ·분석하여 다음과 같은 결과를 얻었다. 1.I급 교합관계를 형성하기 위해서 제 1대구치는 평균 2.94± 1.54mm 원심이동하였으며 . 1.17±0.97mm 함입되었고, 소요기간은 평균 18.13±7.95일이었다. 2.고정 원으로 사용된 치아는 1.34± 1.40mm로 유의하게 전방 이동하였으며, 0.48±0.99mm 정출되었다. 또한 절치는 유의한 전방이동 및 순측경사가 발생하였다(P<0.05) . 3.구개평면과 하악평면이 이루는 각은 유의한 증가를 보였다(P(0.05). 4.제1소구치 또는 제1유구치가 고정 원으로 이용된 경우 제2소구치 또는 제2유구치가 이용된 경우 보다 전방이동이 증가하였다(P<0.005). 5. 제2대구치의 발육단계에 따른 제1대구치 및 제2대구치의 이동양상은 어떤 항목과도 유의성이 없었다(P<0.05). 6.얻어진 총 공간 중 74%는 제1대구치의 원심이동이,26%는 소구치의 전방이동에 의하여 얻어졌다. 이상의 결과를 종합하여 볼 때 pendulum appliance는 상악 대구치의 원심이동에 매우 효과적이었으며. 고정원의 소실을 최소화하기 위해 제2유구치 또는 제 2소구치가 포함되어야 한다. 또한 제1대구치의 원심경사는 필연적으로 일어나며. 이를 최소화하기 위한 노력이 계속되어야 할 것으로 사료된다. Treatment of class Ⅱ malocclusions require distalization of maxillary molars into class I relationship. Intra-arch distal molar movement techniques have recently assumed an important role in young patients. In this study, the dental and skeletal effects of the pendulum appliance were evaluated by means of cephalometric radi-ographs. The samples were consisted of 19 patients: 11 females and 8 males, mean age 11.68± 1.52 years. Measurements were obtained from cephalometric prior to and the day of removal of the pendulum appliance. Treatment changes were analyzed. The following results were obtain : 1. The pendulum appliance produced 2.94±1.54mm distal molar movement with a mean intrusion of 1 17± 0.97mm, mean period 18.13±7.95 weeks. 2. The anchor tooth was 1.34± 1.40mm forward movement and 0.48±0.99mm extrusion, and labial tilting of incisors. 3. The angle between palatal plane and mandibular plane increased significantly 4 There was no significant difference in according to 2nd molar position. 5. Total movement was consisted of 74% distal movement of 1st molar and 26% forward movement of the an-chor tooth

정조(正祖) 초장지(初葬地) 출토 옥의 과학적 분석 및 보존처리

이태종,오정현,김사덕,이정민,Lee, Tae-jong,Oh, Jung-hyeon,Kim, Sa-dug,Lee, Jung-min 국립문화재연구원 2013 헤리티지:역사와 과학 Vol.46 No.4

This research aims to understand the precise character of relics based on literature search and material analysis of the jade excavated from the first buried place of King Jung-jo, and to assess the level of damage through non-destructive diagnosis. Furthermore, scientific conservation treatment was used to restore the original shape of the excavated jade. According to literature search, the excavated jade is known to be jasper, but material analysis showed that it was as a serpentine with the mineral composition of antigorite. Infrared thermography analysis to assess deterioration showed that the internal damage is the result of the interstices developed along the boundary surface of the obtained jade. For conservation treatment of the damaged area on the surface, the jade was filled with a mixture of plaster and glue, and covered with a mixture of acrylic paint and gloss medium for protection, and color was adjusted. 본 연구는 정조 초장지에서 출토된 옥에 대한 문헌조사와 재질분석을 통해 유물의 재질 특성을 밝히고 비파괴진단을 통해 출토 옥의 손상도를 평가하였다. 또한 과학적 보존처리를 실시하여 출토 옥의 원형을 복원하였다. 문헌조사 결과 출토 옥은 벽옥으로 알려졌으나 재질분석 결과, 출토 옥은 안티고라이트(Antigorite) 광물조성의 사문암으로 판단된다. 열화상분석 등 손상도 평가 결과 내부손상 부분은 포획물의 경계면을 따라 발달한 간극에 의한 것으로 나타난다. 표면손상 부분의 보존처리는 석고와 아교를 혼합하여 충전하였으며 보존처리용 아크릴물감과 그로스미디엄을 혼합한 후 색맞춤하였다.

Possible Delayed Recurrence of Sporadic Spinal Hemangioblastoma after Complete Surgical Resection: A Case Report

Jung Bongmin,Kim Soo Yeon,Choe Woo Jin,Lim So Dug 대한말초신경학회 2021 The Nerve Vol.7 No.2

Spinal cord hemangioblastoma (HBL) is a highly vascularized tumor that occurs sporadically or in relation to von Hippel-Lindau disease. Sporadic-type HBLs in the spinal cord usually present as single lesions that are potentially curable by complete surgical resection, with a low rate of recurrence. We report a case of a totally excised sporadic-type spinal cord HBL with multiple recurrences observed 10 years after surgery. Long-term follow-up may be necessary for spinal cord HBL, even in cases of complete resection.

Comparison of different impression techniques for edentulous jaws using three-dimensional analysis

Jung, Sua,Park, Chan,Yang, Hong-So,Lim, Hyun-Pil,Yun, Kwi-Dug,Ying, Zhai,Park, Sang-Won The Korean Academy of Prosthodonitics 2019 The Journal of Advanced Prosthodontics Vol.11 No.3

PURPOSE. The purpose of this study was to compare two novel impression methods and a conventional impression method for edentulous jaws using 3-dimensional (3D) analysis software. MATERIALS AND METHODS. Five edentulous patients (four men and one woman; mean age: 62.7 years) were included. Three impression techniques were used: conventional impression method (CI; control), simple modified closed-mouth impression method with a novel tray (SI), and digital impression method using an intraoral scanner (DI). Subsequently, a gypsum model was made, scanned, and superimposed using 3D analysis software. Mean area displacement was measured using CI method to evaluate differences in the impression surfaces as compared to those values obtained using SI and DI methods. The values were confirmed at two to five areas to determine the differences. CI and SI were compared at all areas, while CI and DI were compared at the supporting areas. Kruskal-Wallis test was performed for all data. Statistical significance was considered at P value <.05. RESULTS. In the comparison of the CI and SI methods, the greatest difference was observed in the mandibular vestibule without statistical significance (P>.05); the difference was < 0.14 mm in the maxilla. The difference in the edentulous supporting areas between the CI and DI methods was not significant (P>.05). CONCLUSION. The CI, SI, and DI methods were effective in making impressions of the supporting areas in edentulous patients. The SI method showed clinically applicability.

Case Report : Acute oxalate nephropathy caused by ethylene glycol poisoning

( Jung Woong Seo ),( Jong Ho Lee ),( In Sung Son ),( Yong Jin Kim ),( Do Young Kim ),( Yong Hwang ),( Hyun Ah Chung ),( Hong Seok Choi ),( So Dug Lim ) 대한신장학회 2012 Kidney Research and Clinical Practice Vol.31 No.4

Ethylene glycol (EG) is a sweet-tasting, odorless organic solvent found in many agents, such as anti-freeze. EG is composed of four organic acids: glycoaldehyde, glycolic acid, glyoxylic acid and oxalic acid in vivo. These metabolites are cellular toxins that can cause cardio-pulmonary failure, life-threatening metabolic acidosis, central nervous system depression, and kidney injury. Oxalic acid is the end product of EG, which can precipitate to crystals of calcium oxalate monohydrate in the tubular lumen and has been linked to acute kidney injury. We report a case of EG-induced oxalate nephropathy, with the diagnosis confirmed by kidney biopsy, which showed acute tubular injury of the kidneys with extensive intracellular and intraluminal calcium oxalate monohydrate crystal depositions.