• The Journal of Korean Physical Therapy
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• 제21권4호
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• pp.43-49
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• 2009

Purpose: This study examined the dynamic peak plantar pressure under the foot areas in those with a functional leg length inequality. Methods: The dynamic peak plantar pressure under the foot areas in an experimental group with a functional leg length inequality (n=20) and a control group (n=20) was assessed a using the Mat-Scan system (Tekscan, USA). The peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th metatarsal head (MTH), mid foot, and heel was measured while the subject was walking on the Mat-Scan system. Results: The experimental group had significantly higher peak plantar pressure under all foot areas when the dynamic peak plantar pressure in the short leg and long leg sides was compared. The control group had a significantly higher peak plantar pressure under the 1st, 2nd, 3-4th, and 5th MTH when the dynamic peak plantar pressure in the short leg and long leg sides were compared. The experimental group showed a significantly larger difference in the dynamic peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th MTH, mid foot and heel than the control group. Conclusion: A functional leg length inequality leads to an increase in the weight distribution and dynamic peak plantar pressure in the side of the short leg.

• 치과방사선
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• 제21권2호
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• pp.317-326
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• 1991

The purpose of this study was to establish the principle and the clinical application of dynamic tomogram of a human head by using the dental machine. For this study, a block of wax with details lying at three parallel planes and a human dry skull were used. This experiment was reexamined the dynamic tomogram with specialized radiographic device and view box, and the radiograms taken by the change of exposure time according to the numbers of film used in x-ray taking and taken according to the change of kVp and the types of film were analyzed density with the densitometer. From this study, the obtained results were as follows: 1. When the underexposed radiograms taken by angulation of clockwise and counter-clockwise direction of the film and skull. were superimposed and moved laterally, it was possible to focus on right and left jaws and teeth. 2. The superimposition of the two underexposed radiograms according to each condition of x-ray taking showed some differencies in density visually, and the measurement of density with the densitometer was 1.23 to 1.57 in 75kVp and 1.34 to 1.70 in 90kVp. 3. The superimposition of the two underexposed radiograms according to the kinds of x-ray film showed almost equal density visually, and the measurement of density with the densiometer was 1.34 to 1.37. 4. When seven radiograms taken by each condition of x-ray taking were superimposed on the view box, a intense rear light of view box didn't transilluminate film density regardless of the conditions of x-ray taking. Even though seven radiograms taken according to types of film were superimposed on the view box, a more intense rear light of view box was required to transilluminate total density of films. 6. Long film-object distance resulted in the enlargement and blurring of radiographic images.

• International Journal of Fluid Machinery and Systems
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• 제6권2호
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• pp.87-93
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• 2013

In order to study the effect of the fluid-structure interaction (FSI) on the simulation results, the external characteristics and internal flow features of a diffuser pump were analyzed with a two-way flow solid coupling method. And the static and dynamic structure analysis of the blade was also caculated with the FEA method. The steady flow field is based on Reynolds Averaged N-S equations with standard $k-{\varepsilon}$ turbulent model, the unsteady flow field is based on the large eddy simulation, and the structure response is based on elastic transient structural dynamic equation. The results showed that the effect of FSI on the head prediction based on CFD really exists. At the same radius, the van mises stress on the nodes closed shroud and hub was larger than other nodes. A large deformation region existed near inlet side at the middle of blades. The strength of impeller satisfied the strength requirement with static stress analysis based on the fourth strength theory. The dynamic stress varied periodically with the impeller rotating. It was also found that the fundamental frequency of the dynamic stress is the rotating frequency and its harmonic frequency. The frequency of maximum stress amplitude at node 1626 was 7 times of the rotating frequency. The frequency of maximum stress amplitude at node 2328 was 14 times of the rotating frequency. No matter strength failure or fatigue failure, the root of blades near shroud is the key region to analyse.

• 한국정보통신학회논문지
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• 제19권3호
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• pp.715-723
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• 2015

본 논문에서는 이동 에드혹 네트워크(Mobile Ad hoc Network: MANET)에서의 상황인식 기반의 스케쥴링 기법인 DDV(Dynamic Direction Vector)-hop알고리즘을 제안한다. 기존 MANET에서는 노드의 이동성으로 인한 동적 네트워크 토폴리지, 네트워크 확장성 결여의 대한 취약성을 지니고 있다. 본 논문에서는 계층적 클러스터 단위의 동적인 토폴로지에서 노드가 이동하는 방향성 및 속도에 대한 노드의 이동 속성 정보를 고려하여 클러스터를 생성 및 유지하는 DDV-hop 알고리즘을 제안한다. 제안된 알고리즘은 클러스터 헤드노드를 기준으로 클러스터 멤버노드의 방향성 및 속도의 속성 정보를 비교하여 유사한 노드간 클러스터링을 구성하고, 이로부터 헤드노드를 선택하는 방법이다. 실험결과, 제안하는 알고리즘이 네트워크의 부하를 감소시키고 네트워크 토폴로지를 안정적으로 유지할 수 있음을 확인하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.925-928
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• 2010

무선 센서 네트워크는 제한된 에너지 자원을 갖는 많은 수의 센서 노드로 구성되어 있다. 제약된 에너지로 인해 정보를 효율적으로 수집하는 것은 무선 센서 네트워크의 중요한 문제이며 클러스터링 알고리즘 기술이 에너지 소비를 줄이기 위해 사용된다. 이러한 기법은 무선 네트워크의 확장성 및 수명을 향상시킬 수 있다. 본 논문에서는 무선 센서 네트워크를 위한 CPMS 클러스터링 프로토콜을 제안한다. CPMS 는 BCDCP(Base Station Controlled Dynamic Clustering Protocol) 나 BIDRP(Base Station Initiated Dynamic Routing Protocol)에 비해 우수한 성능을 보인다. CPMS 는 클러스터를 구성하고 잔존 에너지 비율이 높은 헤드 노드가 BS(BaseStation)로 데이터를 전송하게 한다. 또한 이 기법은 모드 선택 기법을 통하여 헤드 노드의 에너지를 절약할 수 있다. 시뮬레이션 결과 CPMS 는 현재의 클러스터링 기법보다 생존시간 및 메시지 전송량에서 우수한 성능을 보여준다.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.159-165
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• 2002

Purpose: The aim of this study was to introduce a method of obtaining the oscillation graphs of the dental x-ray tube heads relative to time using an accelerometer. Materials and Methods: An Accelerometer, Piezotron type 8704B25 (Kistler Instrument Co., Amherst, NY, USA) was utilized to measure the horizontal oscillation of the x-ray tube head immediately after positioning the tube head for an intraoral radiograph. The signal from the sensor was transferred to a dynamic signal analyzer, which displayed the magnitude of the acceleration on the Y-axis and time lapse on the X -axis. The horizontal oscillation of the tube head was measured relative to time, and the settling time was also determined on the basis of the acceleration graphs for 6 wall type, 5 floor-fixed type, and 4 mobile type dental x-ray machines. Results : The oscillation graphs showed that tube head movement decreased rapidly over time. The settling time varied with x-ray machine types. Wall-type x-ray machines had a settling time of up to 6 seconds, 5 seconds for fixed floor-types, and 1 I seconds for the mobile-types. Conclusion: Using an accelerometer, we obtained the oscillation graphs of the dental x-ray tube head relative to time. The oscillation graph with time can guide the operator to decide upon the optimum exposure moment after x-ray tube head positioning for better radiographic resolution.

• 한국컴퓨터정보학회논문지
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• 제25권8호
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• pp.145-150
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• 2020

전방머리자세는 머리와 목의 잘못된 자세 정렬 중 하나로 비정상적인 관절 위치감각과 고유수용성 감각손상으로 인해 목의 통증과 균형 손상까지 발생시키는 주요 원인으로 알려져 있다. 키네시오 테이핑은 통증관리를 위해 사용되는 임상적인 중재방법으로 통증감소, 혈액순환 촉진, 근육이완을 유도하여 관절 위치 교정 및 근육과 관절에 안정성을 제공하는 효과를 가지고 있다. 이전의 많은 연구에서 키네시오 테이핑을 활용하여 목 통증감소와 목의 정렬에 긍정적인 효과가 있음을 입증하였지만 일부 연구에서는 통증 완화의 효과를 입증하지 못한 부분도 있다. 키네시오 테이핑 적용 후 즉각적인 통증완화 및 정렬 개선에 효과를 보이긴 하지만 적용이후 효과의 지속에 대해서는 증거가 충분하지 않고 임상적으로 더 큰 가치를 보이기 위해서는 키네시오 테이핑의 장점에 대해서 추가적인 연구를 권장하였다. 따라서 본 연구는 앞머리 자세를 가진 사람에서 키네시오 테이핑이 머리 자세의 정렬과 동적 균형 능력에 미치는 영향을 조사하고자 한다.

• 정보저장시스템학회논문집
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• 제1권2호
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• pp.161-168
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• 2005

This paper optimizes the optical flying head(OFH) suspension using the integrated optimization frame, which automatically integrates the analysis with the optimization and effectively implements the repetitive works between them. The problem formulation for the optimization is suggested to improve the dynamic compliance of OFH and to shift the resonant frequencies caused tracking errors to high frequency domain. Furthermore, the minimization of the effective suspension mass that leads to decrease the so-called 'lift-off' as the disk-head separation acceleration divided by the suspension load is taken into consideration. In particular, this study is carried out the optimal design considering the process of modes tracking through the entire optimization processes. The advanced suspension that reduces the effective mass of the suspension and increases the resonant frequencies of sway and $2^{nd}$ torsion over 10kHz is achieved by using the integrated optimization frame.

• 대한통합의학회지
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• 제1권2호
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• pp.81-92
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• 2013

Purpose : This research was carried out to find how neck exercise program combined with self stretching and muscle strengthening program influences on smart phone addicts with forward head posture. Methods : The subjects of this study were 20 smart phone-addicts with forward head posture and we divided them into 2 groups. The experimental group(10 people) participated in neck exercise program as a intervention for 3 months and the control group(the other 10 people) didn't participate in neck exercise program. Neck exercise program were composed of self stretching and muscle strengthening program. Then we measured cervical alignment with GPS(Global Posture System) and evaluated balance ability with Balance Master ver 7.0 systems. Results : The result were as follows. 1. After the intervention, experimental group were significantly more closed to normal cervical alignment than control group. 2. After the intervention, experimental group increased in dynamic balance ability a little more than control group. Conclusion : Neck exercise program seems to get cervical alignment better and improve balance ability.

• 대한의용생체공학회:의공학회지
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• 제20권3호
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• pp.283-290
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• 1999

Mr(Magnetic Resonance ) 영상은 인체 기관의 상태에 관한 많은 정보를 가지고 있어 이것을 분석하여 가시화하면 의료 진단에 유용하게 이용될 수 있다. MR 영상의 가시화는 영상의 획득, 전처리, 조직 분류, 보간, 렌더링의 단계로 이루어진다. 이 단계 중 Mr 영상의 불완전성 때문에 현재 조직 분류 및 보간이 문제로 되어 있다. 본 논문에서는 머리 MR 영상을 대상으로 조직 분류 및 보간에 대한 기법을 제안하고 제안된 기법을 바탕으로 뇌를 3차원 가시화한다. 조직 분류 기법에서는 뇌조직 성분 구성 등 임상 실험에 의해 밝혀진 뇌에 대한 구조적인 지식을 단계적으로 이용한다. 보간 기법은 오목 윤곽선에 사용할 수 있게 동적 탄성 보간기법을 개선하였다. 제안한 구조적인 분류 기법 및 보간 기법을 다른 기법과 비교 평가한다.