• 한국운동역학회지
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• 제27권2호
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• pp.149-155
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• 2017

Objective: The purpose of this study was to investigate the effects of three visual conditions (eyes opened, eyes closed, and wearing of a head mounted display [HMD]) on single-leg standing through kinematics and kinetic analysis. Method: Twelve college students (age: $24.5{\pm}2.6years$, height: $175.0{\pm}6.4cm$, weight: $69.2{\pm}5.1kg$) participated in this study. The study method adopted three-dimensional analysis with six cameras and ground reaction force measurement with one force plate. The analysis variables were coefficient of variation (CV) of the center of body mass, head movement, ground reaction force, and center of pressure, which were analyzed using one-way analysis of variance with repeated measures according to visual conditions. Results: In most cases, the results of this study showed that the CV was significantly higher in the order of HMD wearing, eyes closed, and eyes opened conditions. Conclusion: Our results indicated that body sway was the largest in the HMD wearing condition, and the risk of falling was high owing to the low stability.

• 대한두경부종양학회지
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• 제34권1호
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• pp.33-36
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• 2018

Hyalinizing trabecular tumor (HTT) of the thyroid gland is a rare neoplasm and only less than 100 cases have been reported so far. It is characterized by hyalinizing stroma with trabecular growth pattern and has an indolent clinical course. Because of its histologic features, it is frequently misdiagnosed as papillary or medullary carcinoma in fine needle aspiration cytologic findings. The tumor is benign or low malignant potential and thyroid lobectomy is recommended for adequate treatment. We recently experienced a case of thyroidal HTT in a 57-year-old man, who presented with a right thyroid nodule that was suspicious of papillary carcinoma in aspiration cytology. We report the unique and rare disease entity with brief literature review.

• 한국전기전자재료학회논문지
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• 제21권2호
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• pp.93-98
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• 2008

We investigated the effect of process temperature on removal rate and non-uniformity based on single head kinematics in oxide CMP. Generally, it has been known that the temperature profile directly transfers to the non~uniformity of removal rate on the wafer, which has similar tendency with the sliding distance of wafer. Experimental results show that platen velocity is a dominant factor in removal rate as well as average temperature. However, the non-uniformity does not coincide between process temperature and removal rate, due to slurry accumulation and low deviation of temperature. Resultantly, the removal rate is strongly dependent on the rotational speed of platen, and its non -uniformity is controlled by the rotational speed of polishing head. It means lower WIWNU (With-in-wafer-non-uniformity) can be achieved in the region of higher head speed.

• 임상이비인후과
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• 제29권2호
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• pp.321-326
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• 2018

Warthin's tumor is the second most common benign tumor of the parotid gland, which consists of epithelial and lymphoid components. Malignant change is known to be extremely rare. In Korean literature, only a case of low grade adenocarcinoma arising from Warthin's tumor was reported. For squamous cell carcinoma, there has never been reported in Korea. The authors report a case of squamous cell carcinoma arising from Warthin's tumor in a 77-year-old male, who was treated with primary resection. The patient is well without any recurrence or metastasis after 15 months of follow-up.

• 대한두경부종양학회지
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• 제38권2호
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• pp.1-5
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• 2022

Due to the low incidence and histologic diversity of salivary gland cancer, analyzing the incidence of salivary gland cancer is necessary to understand the macroscopic aspects. We intend to investigate the international trend of the reported incidence rate of salivary gland cancer. Using the Korea Central Cancer Registry data, the domestic change in the incidence rate was examined. As a result, a significant increasing trend was confirmed, consistent with the United States and Japan trends. The etiology of the change is unclear, and various factors that may influence the direction are reported. Additional research is needed to understand the pathophysiology of salivary gland cancer, and further efforts are required to understand salivary gland cancer.

• Journal of Korean Neurosurgical Society
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• 제65권3호
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• pp.385-396
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• 2022

Abusive head trauma (AHT) in infants, especially acute subdural hematoma, has an extremely poor outcome. The most decisive and important finding is the appearance of a widespread low-density area on head computed tomography. This phenomenon was traditionally thought to be caused by cerebral ischemia. However, many other pathophysiological abnormalities have been found to be intricately involved. Recent studies have found that status epilepticus and hyperperfusion injures are the major causes. Another serious problem associated with AHT is cardiopulmonary arrest (CPA). Many infants are reported to visit to the hospital with CPA, and its pathophysiology has not been fully elucidated. This paper examines the background of these pathological conditions and associated factors and elucidate the pathophysiological mechanisms resulting in poor outcomes in AHT. In addition to the intensity of assault on the head, the peculiar pathophysiological characteristics in infants, as well as the social background specific to child abuse, are found to be associated with poor outcome.

• 대한기계학회논문집B
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• 제29권7호
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• pp.784-794
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• 2005

In the very low specific speed range ($n_s=0.24$ < 0.25, non-dimensional), the efficiency of centrifugal pump designed by a conventional method is very low in common. Therefore, positive-displacement pumps have long been used widely. Recently, since the centrifugal pumps are becoming higher in rotational speed and smaller in size, there expects to develop a new centrifugal pump with a high performance to replace the positive-displacement pumps. The purpose of this study is to investigate the internal flow characteristics of a very low specific speed centrifugal pump and to examine the effect of internal flow pattern on pump performance. The results show that the theoretical head definition of semi-open impeller should be revised by the consideration of high slip factor in the semi-open impeller, and the leakage flow through the tip clearance results in a large effect on the impeller internal flow. Strong reverse flow at the outlet of semi-open impeller reduces the absolute tangential velocity considerably, and the decreased absolute tangential velocity increasese the slip factor with the reduction of theoretical head.

• The Korean Journal of Pain
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• 제5권1호
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• pp.117-120
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• 1992

본 통증치료실에서 요통 및 하지 방사통을 호소하는 30세된 남자환자를 보통 시행하는 횟수 보다 많은 경막외강내 스테로이드 주입중에 발생한 양측 무혈성 골두괴사를 경험하였다. 물론 이 환자는 약국이나 한약방 등에서 약명미상의 약물을 경구투여받고 있었으므로 그것(혹시 스테로이드)으로 인한 원인인지 혹은 단순히 경막외강으로 주입된 스테로이드로 인한것인지는 분명하지 않다. 그러나 최근 피부과 질환으로 인한 스테로이드의 장기복용 및 도포로 무혈성 대퇴골두괴사가 종종 보고되고 있으므로 그 원인일수도 있다는 가정하에 통증치료실에 근무하는 종사자들의 주의를 요하는 뜻에서 이 증례를 보고하는 바이다.

• 한국추진공학회지
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• 제14권5호
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• pp.92-100
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• 2010

75톤급 기술검증용 연소기의 연소안정성 시험이 저압 조건에서 수행되었다. 이 시험에 사용된 두 개의 연소기 헤드 중 하나는 631개의 분사기를 가지며, 다른 하나는 721개의 분사기를 가진다. 631개의 분사기를 갖는 연소기 헤드는 연소압력 30 bar에서 자발 불안정이 발생하였고 721개의 분사기를 갖는 연소기 헤드는 동일한 연소압력과 동일한 유량 조건에서 고주파 연소안정성이 유지됨을 보였다. 그러나 721개의 분사기를 갖는 연소기 헤드는 연소압력 20 bar에서 자발 불안정이 발생하였고 이러한 결과로부터 연소기 헤드의 형상은 안정성 경계 영역을 변화시킴을 알 수 있었다.

• 대한후두음성언어의학회지
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• 제19권2호
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• pp.133-135
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• 2008

Background and Objectives: The voice changes can occur in peritonsillar abscess and the labeling of this changes as a "muffled voice". The aim of this study was to investigate the changes in acoustic feature of voice before and after treatment in patients with peritonsillar abscess. Materials and Method: 12 patients with peritonsillar abscess were enrolled in the study. Acoustic analysis on sustained Korean vowels /a/, /i/ and /u/ were performed before and after treatment. Results: In patients with peritonsillar abscess, the first formant frequency (F1) and second formant frequency (F2) of /a/ were decreased. There was tendency of articulation of back-low vowel /a/ as back-high vowel /u/. F1 of /i/ and /u/ were increased, while F2 were decreased. There was tendency of articulation of front-high vowel /i/ as back-low vowel /a/. The third, forth, fifth formant frequency (F3, F4, F5) of /a/, /i/ and /u/ were decreased although statistically not significant. Conclusion: The anatomical and functional changes of oropharynx by peritonsillar abscess can cause changes in resonance and speech quality. We suggest that these changes could be the cause of 'muffled voice' in patients of peritonsillar abscess.