• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4587-4605
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• 2019

High Efficiency Video Coding (HEVC) suffers from high computational complexity due to its quad-tree structure in motion estimation (ME). This paper exposes an adaptive search range decision algorithm for accelerating HEVC integer-pel ME on GPU which estimates the optimal search range (SR) using a MAP (Maximum A Posteriori) estimator. There are three main contributions; First, we define the motion feature as the standard deviation of motion vector difference values in a CTU. Second, a MAP estimator is proposed, which theoretically estimates the motion feature of the current CTU using the motion feature of a temporally adjacent CTU and its SR without any data dependency. Thus, the SR for the current CTU is parallelly determined. Finally, the values of the prior distribution and the likelihood for each discretized motion feature are computed in advance and stored at a look-up table to further save the computational complexity. Experimental results show in conventional HEVC test sequences that the proposed algorithm can achieves high average time reductions without any subjective quality loss as well as with little BD-bitrate increase.

• Physical Therapy Rehabilitation Science
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• 제12권3호
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• pp.310-319
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• 2023

Objective: The purpose of this study was to investigate the effects of a combination of progressive scapular stabilization exercises, neck and thoracic spine mobilization, and thermoelectric physical therapy on pain, range of motion, muscle strength, and function in patients with acute whiplash injury. Design: A randomized controlled trial design. Methods: A total of 24 subjects were included in this study. They were randomly assigned to an experimental group (n=12) that performed scapular stabilization exercises, neck and thoracic spine mobilization, and physiotherapy, and a control group (n=12) that only performed neck and thoracic spine mobilization and physiotherapy. The pre-test was conducted before the intervention and consisted of a total of 12 treatment sessions of 60 minutes each, three times a week. A posttest was conducted 4 weeks later. Pain, range of motion, muscle strength, and function were assessed before and after intervention. Results: The results of the study showed that there was a significant difference in pain reduction and range of motion and muscle strength improvement in the experimental group, and a significant difference was also found between the experimental group and the control group in terms of functional evaluation. Conclusions: The combination of exercise therapy and joint mobilization technique and physical therapy resulted in greater improvements in pain, range of motion, strength, and function assessment, contributing to improved overall function.

• Physical Therapy Rehabilitation Science
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• 제3권1호
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• pp.63-68
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• 2014

Objective: The purpose of this study was to examine the effects of ankle Kinesio taping on range of motion and agility during exercise in university students. Design: Cross-sectional study. Methods: Thirty subjects were randomly allocated to two groups: taping group (n=15) and non-taping group (n=15). All groups underwent the same exercise program including stretching for 30 minutes. The exercise program proceeded in the following order: five minutes of stretching, a 20-minutes exercise program, and additional five minutes of stretching. Of the eight exercise methods suggested by Purcell et al, seven were chosen (lateral shuffle, forward and backward running, agility ladder, figure-of-8, forward jogging while jumping over cones, wall jumps and zigzags); $90^{\circ}$ cuts with lateral shuffle were omitted. The range of motion of ankle dorsiflexion and plantarflexion was measured using the goniometer. Agility was measured using the side hop test. Results: For ankle range of motion, the taping group showed significant differences in dorsiflexion and plantarflexion on both sides (p<0.05). The non-taping group showed significant differences only in left plantarflexion (p<0.05). There was a significant difference in dorsiflexion on both sides between the taping group and the non-taping group (p<0.05). All groups showed significant differences in agility on the left and right ankle (p<0.05). There was a significant difference in left ankles between the taping group and the non-taping group (p<0.05). Conclusions: Kinesio taping increased range of motion and agility during exercise in university students. Additional research on Kinesio taping for improving range of motion and agility is needed.

• PNF and Movement
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• 제17권2호
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• pp.263-274
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• 2019

Purpose: This article was conducted to determine the immediate effects of unilateral contract-relax (CR) stretching on contralateral knee extension range and to compare both sides of the knee extension range between experimental and control groups. Methods: This study recruited 16 adult males and females with straight leg raising abilities below $90^{\circ}$. The subjects were randomly divided into an experimental group and a control group comprising 8 subjects each. The experimental group performed direct CR stretching on the right hamstring muscles with straight hip extension adduction, and the control group performed indirect CR stretching on the right hamstring muscles with straight hip flexion abduction. Each group performed CR stretching 4 times with 4 repetitions comprising 10 sec of contraction and a 10 sec break between repetitions. Before and after the CR stretching exercises, the subjects' passive knee extensions were measured at the hip in a $90^{\circ}$ flexed position. The subjects' peak force on the right leg and peak pressure on the left leg during each CR stretching exercise were also measured. Results: After doing CR stretching 4 times, each group showed a significantly increased passive knee extension range on both sides, and there was no difference in the passive knee extension ranges between the groups. The peak force on the right leg was significantly higher in the experimental group than the control group. There was no difference in peak pressure between the groups. Conclusion: After applying unilateral CR stretching, the study subjects experienced a significantly increased passive knee extension range on the contralateral side. For patients who find it difficult to apply stretching techniques to knee joints directly, the use of the proprioceptive neuromuscular facilitation technique of CR stretching may be useful in improving the range of the knee joint on the contralateral side without direct treatment.

• 한국음향학회지
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• 제43권4호
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• pp.383-390
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• 2024

수중 이동체의 방사소음을 측정하는 경우 이동체와 수신기 사이의 거리 정보가 중요한 요소이지만 수중에서는 Global Positioning System(GPS)를 사용할 수 없기 때문에 대체 수단이 필요하다. 대체 수단으로써 별도의 음향신호를 이용하여 도달 시간, 도달 시간 차 및 도달 주파수 차 등을 추정하여 거리를 측정한다. 하지만 채널 환경에 의해 오류가 발생하며, 이러한 특이값들은 연속적으로 거리를 측정함에 있어서 장애 요인이 된다. 본 논문에서는 거리 정보를 측정하는 과정에서 발생한 특이값들을 제거하기 위하여 사후 처리로써 V-곡선 형태의 함수로 곡선 적합하여 오류를 감소시키는 방법을 제안한다. 제안한 방법의 성능검증을 위해 모의, 호수 및 해상실험을 수행하였다. 호수실험 결과에서는 Root Mean Square Error(RMSE) 관점에서 약 85 % 정도로 거리 추정 오차가 감소하였다.

• 대한원격탐사학회지
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• 제24권2호
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• pp.91-98
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• 2008

SAR에서 마이크로파의 진행방향으로의 속도성분을 가지고 움직이는 물체는 영상에서 azimuth 방향으로 이동된 위치에 상이 맺힌다는 현상은 이미 잘 알려져 있다. 대부분의 속도측정 알고리즘들은 실제 물체의 위치와 상이 맺힌 위치 사이의 거리를 측정함으로써 속도를 유추하였다. 그러나 움직이는 물체의 실제의 위치를 나타내는 지시자인 도로나 배의 물결모양은 일반적으로 SAR 영상에서의 식별도가 높지 않기 때문에 이러한 방법은 영상취득시의 조건이나 물체의 움직임 정도에 따라 적용이 제한적이다. 이에 본 연구에서는 SAR 원시자료 처리단계의 중간 산물인 range-compressed 영상의 azimuth 차분신호로부터 물체의 속도를 측정하는 새로운 방법을 제안한다. 이 방법은 움직이는 물체에 의한 도플러 중심주파수의 변이가 azimuth 차분신호에서의 위상변화를 일으킨다는 점에 기초한다. 일반적으로 SAR에서 감지하는 지표물의 위상은 SAR의 기하에 의하여 발생하는 도플러 변화율에 따라서 선형적으로 변한다. 이 선형변화위상과 몇 가지 상수 값을 갖는 위상들을 제거하고 남은 신호는 물체의 움직임과 직접적인 관련이 있으므로, 이로부터 속도를 구해낼 수 있다. 이 방법을 실제 ENVISAT ASAR영상을 이용하여 배의 속도를 구하는 데에 적용해 보았으며, 그 결과는 목표물의 위치에 따라 다른 양상을 보였다. 해상에 단독적으로 존재하는 배에 적용하였을 때는 0.1m/s 정도의 차이로 기존의 속도측정 알고리즘의 결과와 잘 일치하였으나, 육지에 인접한 연안의 배는 신호의 교란에 의해서 1m/s 이상의 오차를 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.193-196
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• 2000

In this work, I propose a temperature stable voltage-to-frequency converter in which the output frequency is directly proportional to the input voltage. The output frequency range is from 20㎑ to 60㎑ and the difference between simulated and calculated values is less than about 5％ for this range of output frequency. The temperature variation of sample output frequencies is less than ${\pm}$0.5％ in the temperature range -25$^{\circ}C$ to 75$^{\circ}C$.

• 전자공학회논문지B
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• 제32B권9호
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• pp.1181-1187
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• 1995

In video camera, an automatic video quality compensation method using the dynamic range transform is proposed. The histogram is used to decide the nonuniformness of picture brightness by nonuniform lighting. The gray level is divided four regions, and the histogram is obtained per one field. We introduce a new parameter, nonuniformness, defined by the cumulative difference between its CDF and LCDF. We also propose the decision function of the dynamic range transform constant versus its nonuniformness, and compensate the quality of video automatically.

• 대한기계학회논문집B
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• 제21권7호
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• pp.919-927
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• 1997

The main purpose of this study is to determine bifurcation as the primary instability of a glass melting furnace. Steady-state and unsteady characteristics of natural convection in the partially open cavity as appeared in a glass melting furnace is investigated by using numerical analysis. Three types of convection, such as steady laminar, unsteady periodic or unsteady quasi-periodic convection may occur according to the temperature difference between upper two isothermal surfaces along the depth of cavity in a glass melting furnace. In the temperature difference of 150-900 K between batch and free surface, the larger the temperature difference, the weaker the convection strength and unsteadiness. Since the glass viscosity is increasing exponentially in the lower temperature, the batch freezes the thermofluidic field especially below the surface of it. If the depth of cavity is 0.5 m, the bifurcation to time-dependent natural convection may occur in the range of 60-650 K. If that is 1.0 m, it may occur in the whole range of temperature difference.

• 대한족부족관절학회지
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• 제8권2호
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• pp.191-194
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• 2004

Purpose: Anatomic configuration of the ankle joint is useful information during various ankle procedures. This study was prospectively designed to investigate the sagittal inclination pattern of the ankle joint. Materials and Methods: Lateral standing ankle radiographs from one-hundred people (age: $17{\sim}68$, M:F=45:55) and magnetic resonance (MR) sagittal ankle images from twenty-four people (age: $16{\sim}65$, M:F=14:10) were studied. Post-traumatic, arthritic, or grossly deformed ankles at any reason were excluded. The posterior inclination angle (PIA) of the distal tibia was measured and compared between the lateral and the medial segment. Results: On plain radiographic data, the average PIA of the distal tibia was $6.14^{\circ}{\pm}3.56^{\circ}$ (range $0^{\circ}$ to $14^{\circ}$) in the lateral segment and $13.16^{\circ}{\pm}3.05^{\circ}$ (range $6^{\circ}$ to $22^{\circ}$) in the medial segment. On MR imaging data, the average PIA of the distal tibia was $5.08^{\circ}{\pm}4.26^{\circ}$ (range $1^{\circ}$ to $10^{\circ})$ in the lateral segment and $10.16^{\circ}{\pm}4.87^{\circ}$(range $5^{\circ}$ to $17^{\circ}$) in the medial segment. The PIA between two segments was significantly different. Conclusion: The sagittal configuration of the medial area ankle joint and the lateral area ankle joint has difference in the degree of posterior inclination and shape of curvature.