• Journal of Chest Surgery
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• v.31 no.1
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• pp.7-12
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• 1998

The study in detection of perioperative myocardial infarction by serial ECGs and the analysis of risk factors involved was carried out from January 1994 to July 1996 on 87 consecutive patients undergoing coronary artery bypass grafting. There were significant differences in the mean CK-MB peaks and frequencies of flipping in LDH1/LDH2 among the 3 groups(group I: new Q-wave, group II: S-T change, group III: no ECG change). The ECG was considered positive for postoperative myocardial infarction if the new Q-waves appeared in the postoperative period or if S-T segment changes persisted for more than 48 hours. The hospital mortality rate was 3.3% and the perioperative infarction rate was 17.2%. The following risk factors of the perioperative MI were found: endarterectomy, decreased ejection fraction($\leq$40%) and prolonged aortic cross clamping time. Left main disease, triple vessel disease, 3 or more graft, unstable angina and hypertension did not correlate with myocardial infarction. This study suggests that serial ECGs could be used as means of detecting the perioperative myocardial infarction after coronary artery bypass grafting.

• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.359-365
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• 2020

Developmental dysplasia of the hip broadly includes inadequate development of the hip joint involving the acetabulum or proximal femur, or both. Although ultrasonographic studies in neonates have greatly lowered the frequency of neglected or operatively treated cases, its sensitivity is less than desired. Hip dysplasia without subluxation is commonly diagnosed incidentally and strongly related to degenerative arthritis in females after the 4th decade. Hip dysplasia with subluxation shows symptoms through various periods, depending on its severity, especially for women with onset during pregnancy. A complete physical examination and early treatment for neonates are extremely important for obtaining satisfactory outcomes. To avoid underdiagnosis and to serve appropriate treatment on time, the authors recommend examining any suspicious hips in infants under two years of age. The study will discuss the diagnosis and primary treatment of developmental dysplasia of the hip.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.981-988
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• 2022

The intelligent production plant called smart factories that apply information and communication technology (ICT) are collecting data in real time through various sensors. Recently, researches that effectively applying to these collected data have gained a lot of attention. This paper proposes a method for the tool condition monitoring based on the sound signal generated in machining process. First, it not only detects a fault tool, but also presents various tool states according to idle and active operation. The second, it's to represent the power spectrum of the sounds as images and apply some transformations on them in order to reveal, expose, and emphasize the health patterns that are hidden inside them. Finally, the contrast-enhanced PSD image obtained is diagnosed by using CNN. The results of the experiments demonstrate the high discrimination potential afforded by the proposed sound PSD image + CNN and show high diagnostic results according to the tool status.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.399-417
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• 2008

The aim of this study was to investigate the relationships between bite force, masseter muscle and craniofacial morphology. 141 individuals were included. Bite forces were measured with a bite force transducer(SKT 2004). The facial morphology of the samples was evaluated on the Lateral and PA cephalometric radiographs(Asahi CX-90 SP). Ultrasonographic images were obtained for 36 individuals(Logiq 500). General status of the subjects were also measured for investigating possible relationships. Their relationships were analyzed by means of t-test, Pearson's correlation coefficients and simple regression analysis. In conclusion, bite force of molar was significantly correlated with craniofacial morphology for males and females, but not to masseter muscles. The masseter muscle for males had a significant correlation with craniofacial morphology. The unexpected negative correlations between size of masseter muscle and maxillary width was revealed for males. One possible way to arrive at a plausible explanation for the correlation between masster muscle, bite force and craniofacial morphology of males were the deep layer of masseter muscle had a great influence on males and the superficial layer of masseter muscle had a great influence on females.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.3 no.1
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• pp.97-105
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• 1992

Present study investigated the relationship between children's psychiatric disorders and their mothers' psychological problems. Ninety-one psychiatric outpatients from a children's hospital were classified into three diagnostic groups - internalizing symptom group(n=35), externalizing symptom group(n=35), and developmental disorder group(n=21) - based on their psychiatric problems. A normal control group was formed by matching on the age and education of mothers. Mothers' MMPI profiles which were classified into five types - normal, depression, anxiety disorder, somatization disorder, and personality disorder - were examined in relation with children's diagnoses. The profiles of the mothers in the normal control group were mostly normal, while depressive profiles were dominant among those of the clinical groups regardless of the children's diagnoses. Therefore, the data implied association between children's psychiatric problems and their mothers' psychological problems. A possibility of negative reciprocal interactions between children and their mothers was discussed. It was also suggested that further research need to examine the specific effects of children's psychiatric problems on the psychological adjustment of their mothers, as well as the effects of parental psychiatric problems on the adjustment of their offsprings.

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.37-49
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• 2023

Object : This study aimed to identify the factor structure of Korean-Child Behavior Checklist 1.5-5 Dysregulation Profile (K-CBCL 1.5-5 DP) in infants and toddlers with mental disorders and verify differences in K-CBCL 1.5-5 DP among the diagnosis groups. Methods : The participants were 265 mothers of infants and toddlers with mental disorders who completed K-CBCL 1.5-5 DP. The data was analyzed using AMOS 25.0 and SPSS 25.0. Results : First, the bifactor model was the most suitable for the factor structure of the K-CBCL 1.5-5 DP. Second, there were significant differences among the diagnosis groups, such as communication disorders, pervasive developmental disorders, emotional disorders, and developmental delays. It was confirmed that the pervasive developmental disorder and emotional disorder groups showed significantly higher dysregulation compared with the communication disorder group. Conclusion : This study confirmed that infants and toddlers had dysregulation problems. Using the bifactor model, the multidimensional nature of the K-CBCL 1.5-5 DP was assessed. It was also meaningful that dysregulation could contribute to onset and deepening of symptoms of pervasive developmental disorders and emotional disorders in infancy.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1218-1230
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• 2021

Purpose To compare the per-patient diagnostic performance of simulated abbreviated MRI (AMRI) to that of conventional MRI (CMRI) with full-sequence dynamic gadoxetic acid (GA) enhancement for early-stage hepatocellular carcinoma (HCC) screening in high-risk patients. Materials and Methods A total of 201 consecutive patients at high-risk for HCC, who underwent 3T liver MRI, were included in this retrospective study. The AMRI protocol comprised T2-weighted imaging, hepatobiliary phase imaging after GA injection, and diffusion-weighted imaging. For each patient, two AMRI and CMRI image sets were independently reviewed by two radiologists. Inter-reader agreement was assessed using Cohen's kappa value. A composite reference standard was used to determine the diagnostic performance of each image set for each reader. Results A total of 93 HCCs were detected in 79 patients. The inter-reader agreement was almost perfect for both image sets (κ = 0.839, 0.948). In AMRI, the per-patient sensitivity and negative predictive values (NPV) were 94.9% and 96.4%, respectively. In CMRI, the per-patient sensitivity and NPV were 96.2% and 97.5%, respectively. Conclusion AMRI, using only three sequences, had a comparable diagnostic performance to CMRI in screening early-stage HCC. AMRI could be an alternative HCC screening tool for high-risk HCC patients.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.159-165
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• 2018

The purpose of this study is to provide the basic information for diagnosis and treatment of fatty liver by investigating the relationship of the body $^{18}FDG$ uptake and CT Number in patients with fatty liver. This study was conducted on patients who were admitted to the N hospital from January 2014 to October 2015 underwent PET-CT. This result, the probability of fatty liver was 5 times higher in male. The $^{18}FDG$ uptaking were increased by more than 1.000 times respectively in the Liver RT, Middle liver, Liver LT from patients with fatty liver (p <.05). And the CT Number were decreased by 0.93, 0.88, and 0.92 times respectively in Liver RT, Middle liver, Liver LT from patients with fatty liver (p <.05). In conclusion, significant changes of $^{18}FDG$ uptake rate and CT number according to fatty liver provide reliable information for diagnosis and treatment of fatty liver patients. And it can be used as a basic data for the study of fatty liver predictability.

• The Journal of Korean Association of Computer Education
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• v.5 no.2
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• pp.39-48
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• 2002

It is general that the ICAI(Intelligent Computer Assisted Instruction) consists of 4 modules. Export module, Teacher module, Student module and Interface module. In each module construction, there should be some rules to control strategies efficiently and systematically that are related to the texts and assessment instruments, assessment results and evaluation, feedback, etc. It is necessary to use a method to classify the curriculum into sections with units and to represent the identified relationships between them. These relationships are available to all the process of learning, assessment, evaluation and feedback. In this paper, we propose the method to represent these units and relationships as a graph. In addition, we implement an internet-based courseware authoring tool to support the environment in which several expert can construct concurrently the courseware with cooperation between them.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.564-564
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• 2013

홀 추력기는 플라즈마를 이용하는 전기추력기 중 하나로, 인공위성의 자세제어, 궤도수정, 궤도천이 뿐만아니라 행성간 임무수행을 위한 우주선의 엔진으로 사용된다. 홀 추력기 채널 내부에 발생된 Xe 이온들은 양극과 음극 사이에 존재하는 전기장에 의해 가속되어 추력을 발생시킨다. 이때 Xe 이온들은 자기장에 의해 감금된 전자와 중성 Xe 원자 사이의 충돌에 의해 발생하며, 실험적 및 이론적 연구를 통해 단일 전하를 띤 이온(Xe II)뿐만 아니라 다중 전하(Xe III 등)를 띤 이온도 생성되는 것으로 알려져 있다. 이온의 전하량 비율은 홀 추력기의 추력효율 및 연료효율에 영향을 미치며, 다중 전하를 띤 이온의 높은 에너지는 채널벽의 침식문제를 야기하는 등 홀 추력기 이온빔의 전하량 분석 연구는 물리적 연구측면 뿐만아니라 실용적인 측면에서도 매우 중요하다. 본 연구에서는 자기장과 그에 수직한 방향의 전기장에서 발생하는 로렌츠 힘을 이용하여 이온의 전하량을 분석할 수 있는 $E{\times}B$ 탐침을 설계 및 개발하였다. 개발된 $E{\times}B$ 탐침은 70 mm 길이의 집속기와 $148{\times}138{\times}90mm$의 본체, 40 mm길이의 콜렉터로 구성된다. $E{\times}B$ 탐침 설계에 가장 중요한 균일한 자기장 설계를 위해 전산모사를 통해 최적화 작업을 진행하였으며, 실험을 위한 진단계의 최적화와 초기 실험결과가 발표될 예정이다.