• 말소리와 음성과학
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• 제4권2호
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• pp.115-120
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• 2012

This study sought to compare breath competence in three different utterance conditions when reading a passage aloud, making a spontaneous speech, and singing. We tested 15 normal females (ages averaging $24{\pm}4.4$) and measured breath competence through an objective, aero-mechanical instrument called PAS (Phonatory aerodynamic system, model 6600, KAY Electronics, Inc). Breathing sets of inspiration and expiration were measured by breath group number, breath group duration, and the ratio of inspiration to expiration. The results from this study led us to the following conclusion: The breath group number and the breath group duration showed no significant difference. However, the only variance that we could find was in the ratio of inspiration and expiration. In significantly different speech patterns, singing resulted in the most varied ratio of inspiration and expiration, followed by reading a text aloud, and spontaneous speech. The average frequency rates and maximum intensity levels varied with regards to varying utterance conditions. This thus shows that breath competence and phonation competence have a closely interrelated relationship.

• 한국기계가공학회지
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• 제16권5호
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• pp.1-6
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• 2017

Gear tooth micro-geometry modifications include the intentional removal of material from the gear teeth flanks, so that the shape is no longer a perfect involute. If the gear shapes are perfect, then the gear tooth meshing is better, therefore the gears will transmit input torque in a more efficient manner without the generation of high frequency engine fluctuation noise. In this paper, we study tooth micro-geometry optimization of rear gear set in 2 speed planetary gear reducers. Analysis revealed problems which are need of modification. Based on the results, tooth micro-geometry was used to deal with load distributions on the rear gear set.

• 한국생산제조학회지
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• 제18권6호
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• pp.551-557
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• 2009

A development of smart materials is becoming a prominent issue on present industries. A smart material, included in functions, is needed for micro fabrication. A shape memory alloy(SMA) in a smart material is best known material. Ni-Ti alloy, composed of nikel and titanium is one of the best shape memory alloy(SMA). Nitinol SMA is used for a lot of high tech industry such as aero space, medical device, micro actuator, sensor system. However, Ni-Ti SMA is difficult to process to make a shape and fabrications as traditional machining process. Because nitinol SMA, that is contained nikel content more than titanium content, has similar physical characteristics of titanium. In this paper, the characteristics of ECM grooving process for nitinol SMA are investigated by experiments. The experiments in this study are progressed for power, gap distance and machining time. The characteristics are found each part. Fine shape in work piece can be found on conditions; current 6A, duty factor 50%, gap distance 15%, gap distance $15{\mu}m$, machining time 10min.

• 항공우주기술
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• 제12권1호
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• pp.54-63
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• 2013

항공기의 자세제어를 담당하는 각각의 비행 조종면에 중복안정성 등의 이유로 여러 개의 작동기를 연결하여 사용하고 있다. 다중 작동기들이 동시에 정확하게 같은 위치로 이동하지 않으면 비행조종면에 변형이 발생한다. 그 결과 변형된 조종면이 원래 상태로 복원하려는 힘에 의해 작동기들 간에 force fighting이 발생한다. 게다가 force fighting은 각 장치들의 초기 허용 오차 등에 의해서도 발생한다. 다중 작동기간의 force fighting 현상은 제어정밀도에 영향을 미치고 피로파괴의 원인이 되어 작동기와 비행조종면의 수명을 단축할 수도 있다. 본 논문에서는 두 개의 서보작동기를 사용하는 시스템의 force fighting을 감소하기 위하여 힘되먹임제어를 사용하는 제어기를 설계하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.375-380
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• 2021

This study aim was quantitative assessment of MTFs of spectrum of the square wave chart images and Coltman chart images for 0°, 1.7°, 2.2°, 2.9°, 4.1° by using chart method. In general device was AccuRay-650 (DK Medical System, Korea) used, indirect flat panel detector(FPD) Aero (Konica, Japan) used and MATLAB R2019a (MathWorks, USA) used. The result of comparison for each angle of MTF the edge image was highest quantitatively value for MTF finding of showed the best value of 0.1 based on the frequency of 3.5 mm^-1, value of 0.1 based on the square wave was frequency of 3.0 mm^-1 and value of 0.1 based on the Coltman transform was frequency of 2.4 mm^-1. In this study it was significant that the methodology of the international Electro-technical Commission was applied mutandis by using the Fujita method within 2~3°.

• 풍력에너지저널
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• 제2권2호
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• pp.30-37
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• 2011

A floating wind turbine dynamic simulation program, WindHydro, is newly developed taking into account wind inflow and incident wave. WindHydro consists of 5 modules, HDFloat for hydrodynamics, HDProp for hydrodynamic property calculation, HDMoor for mooring dynamics, AeroDyn for aerodynamics, DAFUL for multi-body dynamics with nonlinear elasticity, and interface program that connects each calculation module. A turbulent wind and regular wave load case is simulated for the 5-MW OC3-Hywind with a spar bouy platform and catenary mooring lines. The results are compared with the results of the FAST(developed by NREL). As a result, the overall system responses from WindHydro and FAST agree well although some differences in the generator responses are observed.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.737-740
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• 2009

본 논문에서는 기존 RTLS(Real Time Location Service)시스템의 이동개체에 대한 위치추정오차를 개선하기 위하여, 이동개체속도가 증감되는 각각의 구간을 구분하여 속도가 증감된 만큼 전송신호의 주기를 적응적으로 증감시키는 방법을 제안하였다. 보다 정확한 위치추정 값을 얻기 위하여, AercoScout사의 RTLS 시스템을 이용한 Hybrid(TDOA and RSSI) 방식에 의해 각각 측정된 좌표 값과, 계산에 의해 추정된 좌표 값을 최소자승법(Least Square Method)에 대입하여 실제 이동개체의 위치좌표 값과 비교하는 방법을 취하였다. 실제 제안된 방법에 의해 실험을 해본 결과, 이동개체의 실제 위치의 위치추정오차가 개선됨을 알 수가 있었다.

• 대한한방내과학회지
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• 제36권3호
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• pp.361-379
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• 2015

Objectives This study aims to review and summarize existing evidence on moxibustion treatment for cancer patients. Methods Literature published until May 2015 in international journals were searched on PubMed, CAJ (CNKI-Medicine), NDSL (National discovery for science leaders), Sage Journal, ScienceDirect, Taylor&Francis Online (HSS), and Wiley Interscience (including Blackwell); and articles in Korean journals were searched on Korean Studies Information Service System (KISS), DBPIA, E-Article, KSI e-book, New article, Korea Institute of Science and Technology Information (KISTI), and Kyobo scholar. Results We analyzed 65 relevant studies. The number of studies conducted annually has increased and most are conducted in Korea and China. Moxibustion decreases the side effects of palliative treatment, thereby synergizing with anticancer treatment; it also improves the immune system, reduces tumor factors, and relieves symptoms. The mechanism of moxibustion is multi-fold: thermo, chemo, aero and kinetic. Only the kinetic effect is not significant. It also needs a complement to moxibustion because of harmful smoke. Conclusions Thus, the effect and mechanism of moxibustion in cancer patients was reviewed. There is an unmet need to develop a model of moxibustion and test it based on Korean medicine.

• 한국항공우주학회지
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• 제43권7호
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• pp.601-608
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• 2015

유연날개의 공력 및 구조 설계값을 설계 변수로 하여 정적 상태에서의 정적 공탄성해석 및 최적화를 수행하였다. 정적 공탄성해석과 최적화를 위해 상용 해석소프트웨어들이 연계된 강건한 다분야 최적설계 시스템을 개발하였다. 최적화 설계변수로는 가로세로비, 테이퍼비, 후퇴각과 날개 위아래 스킨 두께를 설정하였다. 전역적 다목적 최적화를 위해 실수기반 적응영역 다목적 유전자 알고리즘을 적용하였으며 계산시간을 줄이기 위해 메타모델로 서포트벡터회귀 기법을 적용하였다. 유연날개에 대한 파레토 결과 분석을 통해 최대 항속시간과 최소 중량에 대한 최적 결과를 확인하였다.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.721-727
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• 2013

본 연구는 모음에 따라 발성역치압력과 비성도의 차이를 비교하고자 하였다. 2012년 5월부터 8월 동안에 대학에 재학 중인 20~30대의 정상성인 여성 28명을 대상으로 실시하였다. 발성역치압력은 객관적인 공기역학적 검사도구인 PAS(Phonatory aerodynamic system, model 6600, KAY electronics, Inc)를 이용하였으며, /p/와 세가지 모음 /a, i, u/를 각 5번씩 측정하여 가운데 3개를 비교하여 분석하였다. 또한 비성도는 Nasometer${\Pi}$(model 6450, KAY electronics, Inc)를 이용하였으며, 세가지 모음 /a, i, u/를 5초 이상 연장발성하여 측정하였다. 그 결과, 모음에 따른 발성역치압력은 유의한 차이를 나타내었으며, 모음에 따른 비성도도 유의한 차이를 보였다. 발성역치압력과 비성도간의 상관관계도 매우 높은 상관성을 나타내었다. 따라서 모음간의 발성역치압력은 연인두 폐쇄정도를 예측할 수 있으며 그에 따른 비성도와 매우 연관성이 깊음을 알 수 있었다.