• 대한기계학회논문집A
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• 제39권12호
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• pp.1251-1256
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• 2015

본 연구에서는 왕복운동 및 회전운동 마찰 실험장치를 이하여 부식금속의 마찰소음특성을 파악하였다. 그 결과 부식금속이 소음발생 시키고 마찰소음의 크기를 증가시키는 것을 확인하였다. 또한, 마찰소음에서 부식의 영향은 마찰표면의 변화로부터 기인하는 것을 관찰할 수 있다. 마찰이 지속적으로 발생될 때 부식금속 마찰계수의 음의 기울기가 증가하여 부식이 되지 않은 금속에 비해 상대적으로 빠르게 불안정해 질 수 있음을 확인하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.147-156
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• 2001

It has been proposed that $Ca^{2+}-activated$ K $(K_{Ca})$ channels play an essential role in vascular tone. The alterations of the properties of coronary $K_{Ca}$ channels have not been studied as a possible mechanism for impaired coronary reserve in cardiac hypertrophy. The present studies were carried out to determine the properties of coronary $K_{Ca}$ channels in normal and hypertrophied hearts. These channels were measured from rabbit coronary smooth muscle cells using a patch clamp technique. The main findings of the present study are as follows: (1) the unitary current amplitudes and the slope conductance of coronary $K_{Ca}$ channels were decreased without changes of the channel kinetics in isoproterenol-induced cardiac hypertrophy; (2) the sensitivity of coronary $K_{Ca}$ channels to the changes of intracellular concentration of $Ca^{2+}$ was reduced in isoproterenol-induced cardiac hypertrophy. From above results, we suggest for the first time that the alteration of $K_{Ca}$ channels are involved in impaired coronary reserve in isoproterenol-induced cardiac hypertrophy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.993-998
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• 2002

Ultra precision processing technology is the field which is seriously protected its technology by advanced nations. Because of this reason, this technology is very difficult to supply for domestic companies, also domestic companies are revealed the limit of technology development by itself. And then, those are depend on the technology development of advanced nation, domestic companies are not conquer application step with already developed parts. Of course, some cases of its research are succeed. those are included element technology, system technology and so on, for development of ultra precision processing system. To conquer technology holding ultra precision processing accuracy of no level, active research are needed. In this paper, stability of ultra precision cutting unit is analyzed, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for un it control.

• 대한의용생체공학회:의공학회지
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• 제35권2호
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• pp.26-34
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• 2014

Little information is available about the characteristics in revolution gait of hemiplegic elderly, which is frequently represented in daily life. It is also hard to elucidate purely the characteristics due to hemiplegia because of no consideration of aging factors. The aim of study is to identify the alteration characteristics of lower extremity joint angles in both straight and revolution gaits together due to hemiplegia through comparing healthy with hemiplegic elderly. Following Institutional Review Board approval, twelve healthy and hemiplegic elderly were participated and the center of body mass (COM) and lower extremity joint angles were measured during straight and revolution gaits using a computer-aided video motion capture system. The results showed that the gait characteristics were generally altered in both straight and revolution gaits due to hemiplegia (p < 0.05). The gait characteristics were then different between the straight and revolution gaits each other. This study may be valuable by identifying for the first time the alterations of the lower extremity joint angles in both straight and revolution gaits due to pure hemiplegia through comparing healthy elderly with hemiplegic elderly.

• Animal cells and systems
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• 제7권2호
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• pp.169-171
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• 2003

Sodium, potassium, calcium, zinc and magnesium levels in the serum of 31 patients diagnosed as acute myocardial infarction were analyzed on admission (within 24 Hours) and after 48 hours. The results were compared with those of 26 age matched controls. No significant difference was observed in the mean sodium, potassium, calcium and zinc levels between the cases and controls. Compared to the controls, however, the variation in the level of magnesium is highly significant at the time of admission as well as after 48 hours. When the risk factors like diabetes mellitus, hypertension, smoking and alcohol were considered, it is found that there is no significant difference between the risk groups as well as between the patients. The alteration in magnesium level in acute myocardial infarction is independent of these risk factors. Within the first 24 hours, the significant decrease in serum magnesium (35-51％ fall when compared with the control group), correlates with its entry into the cell following ischemia. From this hypomagnesemic state, it rises to 9-22 times after 48 hours. This hyper-magnesemia after 45 hours is probably due to the shift of magnesuim from the intracellular fluid compartment to the extracellular fluid compartment that follows cellular recovery. Therefore, including magnesium in the immediate management of acute myocardial infarction will be beneficial in the early recovery.

• 대한전자공학회논문지TC
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• 제42권12호
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• pp.95-102
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• 2005

이 논문은 IEEE802.11a/b/g 무선 랜(Wireless LAN) 억세스 포인트(Access Point)의 성능 향상을 목적으로 한다. 하나의 서버, 멀티 Queue이론, FIFS시스템 모델을 이용하여 우선순위를 적용한 다중 버퍼에 변경된 패킷 구조를 적용하고, MAC에 QoS를 적용한 다중 버퍼를 두고 우선순위가 할당된 데이터에 헤더를 붙여 각각 할당된 다중 버퍼로 전송하여 부하시 생기는 전송지연을 해결하여 전송 효율을 높이고 억세스 포인트의 성능을 향상시키는데 있다. 우리는 여기서 일정 모델의 억세스 포인트와 버퍼 사용에 대한 파라메타를 이용한다. IP 패킷 페이로드의 함수로 패킷의 평균 서비스 타임을 분석하여 파라메타에 적용한다. 버퍼에서 패킷 손실이 생기기 전까지의 수를 계산하여 알고리듬에 구현하고 디자인 한다.

• 한국농촌건축학회논문집
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• 제23권3호
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• pp.27-35
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• 2021

This study aimed to analyze the current status of preservation of buildings in the Cultural Heritage Zone of folk village. Since actual residents inhabit and live in cultural properties, for instance a folk village, so their original forms have been changed over time responding to changes of the social environment. So this present study selected one folk village, located in the largest cultural heritage zone and lived most resident in our country, after which investigated its deformation process. This study also conducted in-depth analysis relying on the data collected from aerial photographs, field surveys, building ledgers. In particular, such analysis focused on changes in unauthorized alteration to the existing state that have been attempted so far. As a result, various variations were found in a number of buildings, caused from damages to landscape of cultural assets. Finally, the reasons for such deformation were interpreted to utilize as future references for restoration of the folk village landscape.

• Physical Therapy Rehabilitation Science
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• 제10권2호
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• pp.134-140
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• 2021

Objective: The purpose of this study was to investigate the alteration of upper cervical manipulation to autonomic nervous system (ANS) through the heart rate variability(HRV) analysis in young healthy individuals. Design: Two-group pretest-posttest design. Methods: Thirty four young healthy participants (17 males and 17 females) were randomized into the 2 groups, such as the upper cervical manipulation group (UCM group, n=17), neck stretching group (NS group, n=17). UCM group received a upper cervical manipulation, especially on the atlas, and NS group did stretch for both side of upper trapezius and levator scapular. For the UCM, Atlas mobility was checked by therapist and thrust was given once at the posterior arch of Atlas. HRV was measured before and after intervention to investigate ANS alteration. After the intervention, both groups were given 3 minutes break-time before measuring HRV. Results: The UCM group showed significant differences in ANS Activity, Stress Resistance, Stress index and Fatigue Index (p<0.05) while no differences in NS group with before and after intervention. There were significant differences in ANS Activity, Stress Resistance, and Fatigue Index between groups (p<0.05). Conclusions: This study suggected that upper cervical manipulationhas positive effects on the ANS activity, stress resistance, and fatigue index.

• 한국음향학회지
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• 제32권5호
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• pp.430-437
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• 2013

본 연구는 정상 청력인에서 시간 변화 (i.e., 압축과 확장)와 선택적 단어 강조법이 문장인지도에 영향을 미칠수 있는지를 평가하였다. 정상 청력을 지닌 성인 20명이 연구에 참여 하였다. 자극음으로 한국표준 일반용 문장표(KS-SL-A)가 사용되었고, 문법적으로는 적절하지만 의미론적으로는 변칙적이고 무의미하게 재구성한 후, 여성 화자에 의해 녹음하였다. 시간 변화는 7단계 (e.g., ${\pm}60%$, ${\pm}40%$, ${\pm}20%$, 0 %)의 압축 및 확장으로 조절하였다. 이 때 선택적 단어 강조법 (i.e., 문장 내에서 특정 단어를 강조)의 효과를 보기 위하여 모든 대상자들에게 2주 간격으로 두 번 검사를 시행하였다. 연구 결과 1) 시간 변화에 따른 문장인지도 정반응률은 60 % 압축 조건에서만 통계적으로 유의하게 낮았다. 2) 선택적 단어의 강조 유무에 따른 문장인지도의 정반응률은 유의한 차이가 없었다. 그러나 6 ~ 7개의 어절로 이루어진 장문장의 자극음을 사용할 경우, 40 % 압축 조건에서 단어가 +6 dB 강조되었을 때, 유의하게 정반응률이 향상되었다. 3) 성별에 따른 문장인지도의 정반응률은 유의한 차이가 없었다. 본 연구의 결과는 조금 빠른 시간 압축과 선택적 단어 강조법을 함께 사용했을 때가 시간 확장만 사용하였을 때보다 문장을 이해하는데 더 효과적임을 시사하고 있다. 그러나 후속 연구에 의한 표준화 자료가 동반되어야 하겠다.

• 전기학회논문지P
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• 제54권1호
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• pp.53-57
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• 2005

When concurrency is integrated to programming language, problem more than inheritance remains yet. Because more than inheritance happens by collision or cross fire between synchronization and inheritance of same time object, when synchronization code is not detached properly from method code about same time object, it makes expanded of code to make derivation class change synchronization code of super class and method code. In this paper, minimize right of inheritance method, When subclass is introduced to new synchronization limitation condition, wish to solve problem more than inheritance of three types that happen in same time programming embodying C++ class that do so that can avoid alteration of method reed.