[논문]실험시설 기초의 진동사용성 분석

최형석,전법규,김남식,정진환 釜山大學校生産技術硏究所 2007 生産技術硏究所論文集 Vol.66 No.-

건물에 작용하는 진동하중은 구조물 자체의 성능에 영향을 미칠 뿐만 아니라 거주하는 사람이나 작업기계 동에 나쁜 영향을 가져올 수 있다. 본 연구에서는 이러한 진동에 대한 영향을 평가하는 국내외의 기준에 대하여 고찰하고 다양한 하중과 주파수 대역에서 실험이 가능한 대형지진모사 실험센터에 대한 진동영향 평가를 수행하여 사용성 저하 여부를 확인하였다.

골형성부전증 10예의 임상적 특징

이형숙,김현주,조재현,이승원,김현아,최준혁,송영준,김대중,이관우,정윤석 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.5

연구배경 및 방법: 골형성부전증은 비교적 희귀한 유전병으로 교원질 대사 장애로 인한 골의 취약성과 다발성 골절 및 척추측만증 등을 특징으로 한다. 유전방식과 표현형의 발현 정도에 따라 다양한 임상 양상을 보이며, 임상적 중증도에 따라 4가지 형태로 분류된다. 지금까지 국내 보고는 분만과정이나 태아 진찰시 골격이상으로 발견된 증례보고가 주였다. 저자들은 비교적 경미한 임상 양상을 보이는 예를 포함한 다수의 골형성부전증 환자들의 전반적인 임상적 특징에 대해 보고하는 바이다. 결과: 2001년 6월부터 2003년 2월까지 골형성부전증으로 진단받은 6 가계, 10예를 대상으로 하였다. 평균 나이는 27.3(5∼56)세였고 소아가 2예였다. 모두 상염색체 우성으로 유전되었으며, 제 I형이 4예, 제 III형이 4예, 그리고 제 IV형이 2예였다. 전 예에서 다수의 골절 경험이 있었고, 골밀도 저하와 골피질 두께 감소 소견이 관찰되었다. 전신의 평균 골밀도는 0.690(0.421∼1.039) g/cm²였다. 골형성지표로 측정된 sAlk는 소아의 경우만 증가되어 있었고, 골흡수지표로 측정된 uDPD의 평균치는 12.9(4.4∼36.3) nM/mM Cr으로 증가된 소견을 보였다. mobility score는 대부분 3,4단계에 속해 있었다. 중증형일수록 진단 시의 mobility score가 낮은 경향을 보였다. 결론: 한국인 골형성부전증 환자의 임상적 특징을 살펴본 결과 기존의 보고된 II형 외에도 I, III, IV형이 다양하게 존재함을 알 수 있었으며, 모든 예에서 상염색체 우성으로 유전됨을 확인할 수 있었다. 또한 모든 예에서 증가된 골흡수로 인한 골밀도 저하와 골절을 확인할 수 있었다. Osteogenesis Imperfecta (OI) is a relatively rare hereditary disease, which is characterized by multiple bone fractures and spine scoliosis, due to the fragility of bone, and is often associated with blue sclerae, deafness and dentinogenesis imperfecta. Four types of OI can be distinguished, according to the clinical findings. Although mutations affecting type I collagen are responsible for the disease in most patients, the mechanism by which the genetic defects cause abnormal bone development remains to be fully understood. Here, the clinical characteristics of 10 OI patient cases are reported, with a review of the literature. All the cases, including 4 type I, 4 type III and 2 type IV, inherited OI as an autosomal dominant trait. All the subjects had multiple old fractures and decreased bone densities. In this study, the biochemical marker of bone formation, serum alkaline phosphatase, was found to be increased only in the pediatric OI patients, while the biochemical marker of bone resorption, urinary deoxypyridinoline, was increased in all cases. The mobility score was found to correlate with the severity of the type on diagnosis (J Kor Soc Endocrinol 18:496∼503, 2003).

Cone beam형 전산화단층영상을 이용한 하악과두 위치의 연구

황형주,김규태,최용석,황의환 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.36 No.2

Purpose : To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Materials and Methods : Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or prosthodontic treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. Results : In the sagittal views, mandibular condyle within articular fossa was posteriorly located at medial and central sections. In the coronal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Conclusion : Mandibular condyle within articular fossa in an asymptomatic population was observed nonconcentric position in the sagittal and coronal views.

초음파영상을 이용한 정상 교근의 평가

황형주,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.2

Purpose : To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Materials and Methods : Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and x²-test. Results : 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Conclusion : Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

전치부 개교합을 가진 골격성 제 Ⅲ급 부정교합 환자에 있어서 하악지 시상분할 골절단술후 술후 안정성에 관한 평가

임재석,권종진,장현석,손형민,남영원,최철민 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.6

The purpose of this study is to assess the postoperative stability and the tendency of relapse after both sagittal split ramus osteotomy in skeletal class III with anterior open bite. This retrospective study was based on the examination of 15 patients, 6 males and 9 females, with a mean age 23.1 years. The patients were divided into two groups based on the amount of preoperative overbite(group I:<1mm, group II:≥1mm). Serial lateral cephalometric radiographs were taken within 2 weeks preoperatively, within 1 week postoperatively and at a follow up period that ranged from 7 to 24 months postoperatively. All cephalometric radiographs were traced and digitized using the Quick ceph image Pro for analysis. And then, horizontal and vertical changes of reference points(B point, Pogonion, L1) were assessed by the linear measurements in millimeters on both axes. The results were as follows : 1 Mean horizontal relapses were 0.67±0.93mm (11%) at B point (P<.05) and 0.81±1.01mm (13.2 %) at Pogonion (P<.01). 2, Mean vertical relapses were 0.63±1.62mm (33.3%) at B point and 0.53±1.95mm (31.4%) at Pogonion (P>.05) 3. The mean angular change of occlusal plane to SN was 0.24±1.19 (P>.05) and that of mandibular plane to SN was 1.03±1.85 (P<.05). 4. There was correlation between the extent of preoperative overbite and the postsurgical relapse at B point and Pogonion. 5. There was no correlation between the amount of surgically produced horizontal movement and the postoperative horizontal relapse at B point.

건축물에서 PCM의 활용가능성에 관한 연구

임병찬,최형섭,최성호,문광석 東亞大學校 建設技術硏究所 2008 硏究論文集 Vol.31 No.2

Many technology have been developed to improve an interior environment in buildings for human being, as well Energy saving. Above all things, Energy saving technology with PCM have been used(applied to) for heating and cooling system in buildings and devoted to save Energy. The technology with PCM can improve energy efficiency in a room. Because it can maintain the temperature, storing the energy which was used for heating and cooling in the room. In this study, we analyze the possibility of PCM as Architectural Materials. Appling PCM which uses latent heat to the building, we try to reduce a loss of heat and maximize the effect of energy saving in the building.

Clinical Presentation and Outcomes of Middle East Respiratory Syndrome in the Republic of Korea

Choi, Won Suk,Kang, Cheol-In,Kim, Yonjae,Choi, Jae-Phil,Joh, Joon Sung,Shin, Hyoung-Shik,Kim, Gayeon,Peck, Kyong Ran,Chung, Doo Ryeon,Kim, Hye Ok,Song, Sook Hee,Kim, Yang Ree,Sohn, Kyung Mok,Jung, You The Korean Society of Infectious Diseases and Kore 2016 Infection and Chemotherapy Vol.48 No.2

<P><B>Background</B></P><P>From May to July 2015, the Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome (MERS) outside the Arabian Peninsula. A total of 186 patients, including 36 deaths, had been diagnosed with MERS-coronavirus (MERS-CoV) infection as of September 30th, 2015.</P><P><B>Materials and Methods</B></P><P>We obtained information of patients who were confirmed to have MERS-CoV infection. MERS-CoV infection was diagnosed using real-time reverse-transcriptase polymerase chain reaction assay.</P><P><B>Results</B></P><P>The median age of the patients was 55 years (range, 16 to 86). A total of 55.4% of the patients had one or more coexisting medical conditions. The most common symptom was fever (95.2%). At admission, leukopenia (42.6%), thrombocytopenia (46.6%), and elevation of aspartate aminotransferase (42.7%) were observed. Pneumonia was detected in 68.3% of patients at admission and developed in 80.8% during the disease course. Antiviral agents were used for 74.7% of patients. Mechanical ventilation, extracorporeal membrane oxygenation, and convalescent serum were employed for 24.5%, 7.1%, and 3.8% of patients, respectively. Older age, presence of coexisting medical conditions including diabetes or chronic lung disease, presence of dyspnea, hypotension, and leukocytosis at admission, and the use of mechanical ventilation were revealed to be independent predictors of death.</P><P><B>Conclusion</B></P><P>The clinical features of MERS-CoV infection in the Republic of Korea were similar to those of previous outbreaks in the Middle East. However, the overall mortality rate (20.4%) was lower than that in previous reports. Enhanced surveillance and active management of patients during the outbreak may have resulted in improved outcomes.</P>

Diagnostic Performance of a New Convolutional Neural Network Algorithm for Detecting Developmental Dysplasia of the Hip on Anteroposterior Radiographs

Park Hyoung Suk,Jeon Kiwan,Cho Yeon Jin,Kim Se Woo,Lee Seul Bi,Choi Gayoung,Lee Seunghyun,Choi Young Hun,Cheon Jung-Eun,Kim Woo Sun,Ryu Young Jin,Hwang Jae-Yeon 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.4

Objective: To evaluate the diagnostic performance of a deep learning algorithm for the automated detection of developmental dysplasia of the hip (DDH) on anteroposterior (AP) radiographs. Materials and Methods: Of 2601 hip AP radiographs, 5076 cropped unilateral hip joint images were used to construct a dataset that was further divided into training (80%), validation (10%), or test sets (10%). Three radiologists were asked to label the hip images as normal or DDH. To investigate the diagnostic performance of the deep learning algorithm, we calculated the receiver operating characteristics (ROC), precision-recall curve (PRC) plots, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and compared them with the performance of radiologists with different levels of experience. Results: The area under the ROC plot generated by the deep learning algorithm and radiologists was 0.988 and 0.988–0.919, respectively. The area under the PRC plot generated by the deep learning algorithm and radiologists was 0.973 and 0.618– 0.958, respectively. The sensitivity, specificity, PPV, and NPV of the proposed deep learning algorithm were 98.0, 98.1, 84.5, and 99.8%, respectively. There was no significant difference in the diagnosis of DDH by the algorithm and the radiologist with experience in pediatric radiology (p = 0.180). However, the proposed model showed higher sensitivity, specificity, and PPV, compared to the radiologist without experience in pediatric radiology (p < 0.001). Conclusion: The proposed deep learning algorithm provided an accurate diagnosis of DDH on hip radiographs, which was comparable to the diagnosis by an experienced radiologist.

유압오일댐퍼를 이용한 수직진동 저감장치 개발

최형석(Choi, Hyoung-Suk),정진환(Cheung Jin-Hwan),박동욱(Park, Dong-Uk),김재봉(Kim Jae-Bong),이종림(Lee Jong-Lim) 한국소음진동공학회 2014 한국소음진동공학회 학술대회논문집 Vol.2014 No.4

동영상 화소분할에 의한 구조물의 동적변위 측정방법

최형석(Choi Hyoung Suk),정진환(Cheung Jin Hwan) 대한토목학회 2010 대한토목학회 학술대회 Vol.2010 No.10