• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.141-145
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• 2014

A minimally appropriate time delay of audio data processing is investigated for rendering virtual sound source direction in real-time head-tracking environment under headphone listening. Less than 3.7 degree of angular mismatch should be maintained in order to keep desired sound source directions in virtually fixed while listeners are rotating their head in a horizontal plane. The angular mismatch is proportional to speed of head rotation and data processing delay. For 20 degree/s head rotation, which is a relatively slow head-movement case, less than total of 63ms data processing delay should be considered.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.80-83
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• 2003

Chondrosarcomas are uncommon tumors. Approximately 5-10% are located in the head and neck. Nasal septal chondrosarcoma is exceedingly rare, with an extensive review of the world literature revealing only 50 reported cases. Most occur in middle-aged man. Surgical resection is the definitive treatment of choice. Radiation and chemotherapy are reserved for residual or recurrent diseases and palliation. We present a case of nasal septal chondrosarcoma treated with craniofacial resection and postoperative radiation therapy.

• Annual Conference on Human and Language Technology
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• 2021.10a
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• pp.544-547
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• 2021

한국어의 품사 태깅 문제는 입력 어절의 형태소 분석 후보들로부터 통계적으로 적절한 품사 태그를 가지는 후보들을 찾는 방식으로 해결하여 왔다. 어절을 형태소 단위로 분리하고 품사를 부착하는 기존의 방식은 품사태그 정보를 딥러닝 feature로 사용할 때 문장의 의미를 이해하는데 복잡도를 증가시키는 요인이 된다. 본 연구에서는 품사 태깅 문제를 단순화 하여 한 어절을 Head와 Tail이라는 두 가지 유형의 형태소 토큰으로 분리하여 Head와 Tail에 대해 품사를 부착한다. Head-Tail 품사 태깅 방법을 Sequence-to-Sequence 문제로 정의하여 Transformer를 이용한 Head-Tail 품사 태거를 설계하고 구현하였다. 학습데이터로는 KCC150 말뭉치의 품사 태깅 말뭉치 중에서 788만 문장을 사용하고, 실험 데이터로는 10만 문장을 사용하였다. 실험 결과로 토큰 정확도는 99.75%, 태그 정확도는 99.39%, 토큰-태그 정확도는 99.31%로 나타났다.

• Korean Journal of Head & Neck Oncology
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• v.39 no.2
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• pp.71-74
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• 2023

Ewing sarcoma is a rare tumor in head and neck area. We demonstrate a rare case of sinonasal Ewing sarcoma initially suspected as olfactory neuroblastoma. After the surgery and immunohistochemical studies, it was accurately diagnosed as Ewing sarcoma. We would like to emphasize the possibility that Ewing sarcoma may originate from the head and neck area, and hence, it is important to use appropriate techniques for accurate diagnosis and treatment.

• Korean Journal of Head & Neck Oncology
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• v.1 no.1
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• pp.15-19
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• 1985

• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.3-8
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• 2008

• The Korean Journal of Physiology
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• v.30 no.2
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• pp.237-247
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• 1996

This study was carried out to determine the effect of $-6^{\circ}$ head-down bedrest on the cardiovascular and hormonal responses to orthostasis and to evaluate the mechanism of orthostatic intolerance. Ten healthy young men were changed the body position from $-6^{\circ}$ head-down or supine bedrest for 2 hr to $70^{\circ}$ head-up tilt for 20 min. During the bedrest, there were no differences in hemodynamic and hormonal changes between the head-down and the supine positions. However, the tendency of decreased end-diastolic volume and increased cardiac contractility during the later period of 2 hr showed that the cardiovascular adaptation could be accelerated within a relatively short period in the head-down bedrest. During the head-up tilt, presyncopal signs were developed in five subjects of the supine bedrest, and one of the same subjects of the head-down bedrest. In the tolerant subjects, the increase in cardiac contractility and plasma epinephrine level during the bend-up tilt was greater following the head-down bedrest than that following the supine bedrest to compensate for reduced venous return. The intolerant subjects showed the greater decrease in end-diastolic and stroke volume, and the greater increase in heart rate during the head-up tilt than the tolerant subjects. Cardiac contractility and plasma epinephrine level were remarkably increased. However, arterial pressure was not maintained at the level for the appropriate compensation of the reduced venous return. It seems that the tolerance to orthostasis is more effective after the short-term head-down bedrest than after the supine bedrest, and the secretion of epinephrine induces the higher cardiac performance as a compensatory mechanism fur the reduced venous return during the orthostasis following the head-down bedrest than the supine bedrest.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1998.04b
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• pp.6-6
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• 1998

In 1957, the first magnetic disk drive compatible with a movable head was introduced as an external file memory device for computer system. Since then, magnetic disks have been improved by increasing the recording density, which has brought about the development of a high performance thin film magnetic head. The thin film magnetic head has a magnetic circuit on a ceramic substrate using IC technology. The physical property of the substrate material is very important because it influences the tribology of head/disk interface and also manufacturing process of the head. $Al_{2}O_{3}$-TiC ceramics, so called ALTIC, is known to be one of the best substrate materials which satisfies this property requirement. Even though the head is not in direct contact with the disk, frequent instantaneous contacts are unavoidable due to its high rotating speed and the close gap between them. This may cause damage in the magnetic recording media and, thus, it is very important that the magnetic head has a good wear resistance. $Al_{2}O_{3}$-TiC ceramics has an excellent tribological property in head/disk interface. Manufacturing process of thin film head is similar to that of IC, which requires extremely smooth and flat surface of the substrate. The substrate must be readily sliced into the heads without chipping. $Al_{2}O_{3}$-TiC ceramics has excellent machineability and mechanical properties. $Al_{2}O_{3}$-TiC ceramics was first developed at Nippon Tungsten Co. as cutting tool materials in 1968, which was further developed to be used as the substrate materials for thin film head in collaboration with Sumitomo Special Metals Co., Ltd. in 1981. Today, we supply more than 60% of the substrates for thin film head market in the world. In this paper, we would like to present the sintering process of $Al_{2}O_{3}$-TiC ceramics and its property in detail.

• Korean Journal of Head & Neck Oncology
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• v.27 no.2
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• pp.210-214
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• 2011

Background and Objectives : Narrow Band Imaging(NBI) is a novel optical technique that enhances the visualization of superficial microvascular architecture which is commonly increased and founded as an irregular shape in a neoplastic lesion. The aim of this study is the evaluation of the usefulness of NBI in the diagnosis of Head and Neck Cancer. Subjects and Methods : From December 2009 to January 2011, 31 consecutive patients who were diagnosed with head and neck malignancy were enrolled in this prospective study. The malignant findings of NBI were demarcated brownish lesion or increased intraepithelial papillary capillary loops(IPCLs) with or without irregularity. Results : There were 29 cases(93.5%) of well demarcated brownish lesion, 26 cases(83.9%) of increased IPCLs and 4 cases(12.9%) of satellite lesions. Diagnostic accuracy of endoscopic examination was increased from 83.9% to 93.5%, when NBI was applied to the conventional endoscopy(p>0.05). Conclusion : NBI is a powerful and safe screening test, which can be performed in out patient clinic without any supplementary procedure.

• Journal of Korean Academy of Nursing
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• v.22 no.2
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• pp.127-142
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• 1992

The purpose of this study was to identify relationships between the nursing performance of staff nurses and the leadership styles of head as perceived by the head nurses and the staff nurses. The subject consisted of 33 head nurses and 200 staff nurses who were working at SNUH between July 1, and July 31, 1991. Leadership styles as perceived by head nurses and staff nurses were measured using an instrument adapted by Park (1988) . Evaluations of the nursing performance of staff nurses were done by head nurses utilizing a questionnaire adopted by Park(1988). Data were analysed using percentage distribution, ANOVA, Scheffe test and Pearson Correlation Coefficient. The results are summarized as follows : 1. The majority of the head nurses and staff nurses perceived the head nurse as having a tendency to exercise high level authority and benevolence oriented leadership. 2. The majority of the staff nurses carried out their nursing performance in a highly skilled manner. 3. There were significant differences in perceptions of leadership style between head nurses and staff nurses. 4. “Authority” and “Benevolence” in leadership style as perceived by the head nurses were related very weakly to the nursing performance of the staff nurse. 5. “Benevolence” of leadership style as perceived by the staff nurses was related very weakly to the nursing performance of the staff nurse. 6. Group comparisons of nursing performance and leadership style found that high nursing performance by the staff nurse was related in the group with high “Authority” as perceived by the head nurse and low “Authority” as perceived by the staff nurse. From the above findings, this study suggests the following : 1) Further studies are needed to control extraneous variables. 2) Efforts in leadership development are needed to enhance nursing performance. 3) Factor exploration study are needed to seek factors that contribute to the perception gap between the head nurse and the staff nurse.