자동차용 컨트롤 링크 업셋 용접부의 용접성 및 피로강도 향상에 관한 유한요소 해석

조해용,권혁홍,이봉규 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.6

This study is concerned with Finite Element Analysis on welded part of control link for automobile. For analysis, control link was modeled into two parts, ring and rod. Heating condition, temperature distributions and fatigue fracture strength were analyzed using "HEAT Ⅲ" and "ENDURE" module of NISA Ⅱ. Metal flow in the process of welding was simulated by DEFORM^TM 2D. The analyzed results were compared with experimental inspection. Quality of welded part was able to be improved by controlling metal flow in the process of welding by increase the friction constant of ring part. Heat transfer analysis and flow simulations were in good agreement with welding experiments.

한국 주요정신장애의 유병률 및 관련요인 : 2006 전국정신질환역학조사

조맹제,장성만,함봉진,정인원,배안,이영문,안준호,원승희,손정우,홍진표,배재남,이동우,조성진,박종익,이준영,김진영,전홍진,이해우 大韓神經精神醫學會 2009 신경정신의학 Vol.48 No.3

Objectives The aims of this study are to estimate the prevalence of the DSM-IV psychiatric disorders in the Korean population using the Korean version of Composite International Diagnostic Interview (K-CIDI), and to compare those with previous studies. Methods The Korean Epidemiologic Catchment Area study Replication (KECA-R) was Conducted between August 2006 and April 2007. The sampling of the subjects was carried out across 12 catchment areas. A multistage, cluster sampling design was adopted. The target Population included all eligible residents aged 181o 64 years. Face-to-face interviews were conducted with the Korean version of Composite International Diagnostic Interview (K-CIDI) based on the DSM-IV (N=6,510, response rate=81.7%). Results A total of 6,510 participants completed the interview. The lifetime and 12-month prevalence rates for all types of DSM-IV disorders were 30.0% and 17.3%, respectively. Those of Specific disorders were as follows : 1) alcohol use disorder, 16.2% and 5.6% ; 2) nicotine use disorder, 9.0% and 6.0% ; 3) specific phobia, 3.8% and 3.4% ; 4) major depressive disorder, 5.6% and 2.5% ; and 5) generalized anxiety disorder, 1.6% and 0.8%. Data relating to nicotine and alcohol use disorder revealed a very high male/female ratio. Mood disorder and anxiety disorder were more prevalent among females than males. Conclusion The prevalence of psychiatric disorders was high. In comparison with other studies, remarkable differences in the distribution of psychiatric disorders across the country and times were observed.

하악과두의 인위적 병소에 대한 악관절 촬영법의 판독능 비교연구

조봉혜,정연화,정희정 大韓口腔顎顔面放射線學會 1997 Imaging Science in Dentistry Vol.27 No.2

The purpose of this study was to evaluate the detectability of various radiographic techniques for mandibular condylar lesions. Erowive lesion, osteophyte and flattening were formed on the artificial mandibular condyle, and panoramic, transcranial, transorbital radiography, lateral and frontal tomography were taken. The results were as follows; 1. The detectability for erosive lesions was superior in the order of frontal tomography(96%), lateral tomo-graphy (78%),transorbital(59%), transcranial(56%) and panoramic(48%)radiography. 2. The location of erosive lesion that showed the highest detectability was the medial third in panoramic, the lateral third in transcranial, the central portion of anteroposterior direction in transorbital, the central portion of mediolateral direction and the posterior third in lateral tomography. Frontal tomography disclosed all erosive lesions except one anterolateral lesion. 3. The detectability of osteophyte was 100% in lateral tomography, 78% in transcranial and 56% in panoramic radiography. 4. For flattening, lateral tomography showed the flattened condyle, but both panoramic and transcranial views showed only decreased bone density without the change of condylar shape.

악관절 단층촬영시의 두경부 주요 기관의 흡수선량

조봉혜 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose : This study was done to evaluate the absorbed doses in organs of the head and neck for the conventional temporomandibular joint tomography. Material and Methods : Dosimetry was performed with 32 LiF thermoluminescent dosimeters, whcih were placed in a tissue-equivalent phantom when the temporomandibular joint was examined by both lateral and frontal temporomandibular joint tomography. Results : For lateral tomography, parotid gland and preauricular area towards tube showed relatively high absorbed dose of 1056.9 μGy and 519.9 μGy respectively. For frontal tomography, the two largest absorbed doses were 259.2 μGy in orbit towards tube and 212.0 μGy in lens towards tube. Conclusion : Conventional temporomandibular joint tomography showed relatively low absorbed doses on critical organs. Thus, responsible use of it may not be limited.(J Korean Oral Maxillofac Radiol 1999;29:411-416)

악관정 내장증 환자의 최대 개구시 하악과두 운동량에 대한 자기공명영상 평가 : 경두개촬영법과의 비교 comparison with transcranial view

조봉혜 大韓口腔顎顔面 放射線學會 2001 Imaging Science in Dentistry Vol.31 No.4

Purpose : To evaluate the condylar movement at maximal mouth opening on MRI in patients with internal derangement. Materials and Methods : MR images and transcranial views for 102 TMJs in 51 patients were taken in closed and maximal opening positions, and the amount of condylar movement was analyzed quantitatively and qualitatively. Results : For MR images, the mean condylar movements were 9.4 ㎜ horizontally, 4.6 ㎜ vertically and 10.9 ㎜ totally, while those for transcranial views were 12.5 ㎜, 4.6 ㎜, and 13.7 ㎜ respectively. The condyle moved forward beyond the summit of the articular eminence in 41 TMJs (40.2%) for MR images and 56 TMJs (54.9%) for transcranial views. Conclusion : The horizontal and total condylar movements were smaller in MR images than in transcranial views. (Korean J Oral Maxillofac Radiol 2001; 31 : 185-92)

중첩 불일치 평가기준으로서의 계수공제영상의 계조도 표준편차 연구

조봉혜 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose : The aim of this study was to assess the validity of standard deviation of gray scale histogram in digital subtraction radiography as a test parameter for superimposition error. Materials and Methods : Twenty periapical radiographs were used as baseline images and they were copied to exclude the influence of exposure geomety and contrast differences. These subsequent images were linearly displaced by 0.1-0.5 mm in the x-, y- and xy-directions, rotated by 0.5-3°and distorted by angular contraction of 1-5° in x- and y-axis before subtraction. The standard deviations of gray levels in the subtraction images were obtained and paired t-tests were performed. Pearson correlation coefficients(r) were calculated between the standard deviations and the superimposition errors. Results : Linear displacement showed high correlation coefficients of 0.997, 0.997 and 0.995 in x-, y- and xy-axis respectively. Statistically significant different standard deviation existed among all linearly displaced groups(p<0.05). Distortion showed relatively low correlation coefficients of 0.982 and 0.959 in x- and y-axis. The standard deviations between the two distortion groups were statistically significant different(p<0.05). Conclusion : Standard deviation of gray level distribution in digital subtraction images is satisfactory but not perfect similarity measure to assess the superimposition errors.(J Korean Oral Maxillofac Radiol 1999;29:417-422)

함치성 낭종으로 오인되는 유치의 근단성 낭종에 관한 연구

조봉혜,나경수 大韓口腔顎顔面 放射線學會 1994 Imaging Science in Dentistry Vol.24 No.2

20 radicular cysts of primary teeth mimicking dentigerous cyst were reviewed. The following results were obtained. 1. The patients' age ranged from 7 to 14 years. Males(60%) were more involved than females(40%) 2. The mandible(85%) was affected more frequently than the maxilla(15%) The mandibular deciduous molar area(80%) was the most frequently involved. 3. The diameter of the cyst varied from 10 to 30㎜. 55% of permanent successors showed underdeveloped roots less than one-third. 4. The etiologic factors were pulp-treated teeth(65%), severe caries(20%), trauma(10%), deep amalgam filling(5%).

규격화된 구내 표준 방사선사진의 계수 공제 방사선학적 평가

조봉혜,나경수 大韓口腔顎顔面 放射線學會 1993 Imaging Science in Dentistry Vol.23 No.1

The geometrically standardized intraoral radiographs using 5 occlusal registration materials were taken serially from immediate, 1 day, 2, 4, 8, 12, and 16 weeks after making the bite blocks. And the resultant images were digitally subtracted using the immediately taken film as reference images. The qualities of those subtracted images were evaluated to check the degree of reproducibility of each impression material. The results were as follows: 1. The standard deviations of the grey scales of the overall subtracted images were 4.9 for Exaflex, 7.2 for Pattern resin, 9.0 for Tooth Shade Acrylic, 12.2 for XCP only, 14.8 for Impregum. the lesser the standard deviation, the better the quality of the subtracted images. 2. The standard deviation of the grey scales of the overall subtracted images were grossly related to those of the localized horizontal line of interest. 3. Exaflex which showed the best subtracted image quality had 15 cases of straight, 14 cases of wave, 1 case of canyon shape. Impregum which showed the worst subtracted image quality had 4 cases of straight, 8 cases of wave, 18 cases of canyon shape respectively.

측두하악관절 내장증에서의 관절원판 전상방부착부의 자기공명영상

조봉혜,정연화 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.36 No.2

Purpose : To describe the MRI findings of the antero-superior attachment of the disc in patients with internal derangement. Materials and Methods : One hundred fifty-six MR images from 40 normal subjects and 55 abnormal subjects were classified into three study groups of normal, anterior disc displacement with reduction and anterior disc displacement without reduction. On both closed- and open-mouth proton density sagittal images, the depiction of the antero-superior attachment of the disc and its demarcation from the disc were evaluated in three cuts of lateral, central and medial one thirds of the condyle. Results : The depiction of antero-superior attachment was more frequent by the order of normal, anterior disc displacement with reduction and anterior disc displacement without reduction groups, and the significant differences were found on lateral cut of the closed images and lateral and central cuts of the open images. In study for the demarcation between the antero-superior attachment and the disc the lateral cut of the closed images and all three cuts of the open images showed significant differences. Conclusion : Open images are useful to show the difference in depiction of the antero-superior attachment of the disc among the TMJ groups.

자기공명영상(Magnetic Resonance Imaging)의 기본원리

조봉혜 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

자기공명영상은 내부의 안정된 자기 핵과의 상호작용을 통하여 반복주사 없이 횡단면, 시상면, 관상면등 원하는 단면의 영상을 얻을 수 있는 촬영법이다. 현재까지 알려진 특별한 위해 작용은 없으며 병리학적으로 정상과 비정상조직을 구별해 낼 수 있으므로 연조직 분석에 특히 유용하다. 그러나 물리화학적 변화에 민감하여 적절한 pulse sequence의 선택과 적용방법이 까다롭다. 자기공명은 화학분석이 가능하여 의학적 사용 외에 물리, 화학, 생화학 분야에도 많이 이용되고 있으며 향후 많은 발전이 있을 것으로 예상된다. Magnetic resonance imaging with its superior soft tissue contrast resolution and absence of beam hardening artifacts, combined with its ability to perform multiplanar imaging, is now effective tool in diagnostic imagings. Magnetic resonance is primarily a phenomenon that involves atomic nuclei. It provides totally new clinical informations with no known hazards through the use of very weak interactions with endogenous stable magnetic atomic nuclei. This article briefly summarizes the basic mechanism of generation and detection of the signals and general sorts of tissue properties which can influence the signals and thereby give rise to tissue contrast. It also describes how the machine-operating parameters can be used to manipulate the tissue contrast observed in the image.(J Korean Oral Maxillofac Radial 1999:29:7-20)