• Journal of the Society of Naval Architects of Korea
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• v.51 no.4
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• pp.265-273
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• 2014

Wave-body interaction is simulated using a developed code based on the flux-difference splitting scheme for immiscible and incompressible fluids and the hybrid Cartesian/immersed boundary method. A free surface is captured as a moving contact discontinuity within a fluid domain and an approximated Riemann solver is used to estimate the inviscid flux across the discontinuity. Immersed boundary nodes are identified inside an instantaneous fluid domain near a moving body, then dependent variables are reconstructed at those immersed boundary nodes based on interpolation along local normal lines to the boundary. Free surface flows around an oscillating cylinder are simulated and the computed wave elevations are compared with other reported results. The generation of a solitary wave by a moving wave-maker is simulated and the time histories of wave elevations at two different points are compared with other results. The developed code is applied to simulate body motion of an elastically mounted circular cylinder as a solitary wave passes the body. The force acting on an elastically mounted cylinder is compared with the force acting on a fixed cylinder. Grid independency of the computed body motion is established based on a comparison of results using three different-size grids.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.485-491
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• 2017

An experimental study on the reduction of vertical motion of floating body using floating-submerged body interaction was performed in a two-dimensional wave channel. The system consisting of a floating and submerged body that only move vertically was modeled. This experiment was designed based on the results of theoretical analysis of two-body interaction. The results showed a tendency to significant reduction of heave RAO of floating body due to submerged body. Various connection line stiffness and dimension of the submerged body were applied to investigate the effect of two-body interaction on the vertical motion of the bodies, Heave RAOs of the floating-submerged body were compared with those of single body. From the comparison study, we obtained an optimum condition of connection line and dimension of submerged body for maximum heave reduction at the resonant period of single body.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.868-874
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• 2014

This paper proposes a novel mapping algorithm in Omni-directional Vision SLAM based on an obstacle's feature extraction using Lucas-Kanade Optical Flow motion detection and images obtained through fish-eye lenses mounted on robots. Omni-directional image sensors have distortion problems because they use a fish-eye lens or mirror, but it is possible in real time image processing for mobile robots because it measured all information around the robot at one time. In previous Omni-Directional Vision SLAM research, feature points in corrected fisheye images were used but the proposed algorithm corrected only the feature point of the obstacle. We obtained faster processing than previous systems through this process. The core of the proposed algorithm may be summarized as follows: First, we capture instantaneous $360^{\circ}$ panoramic images around a robot through fish-eye lenses which are mounted in the bottom direction. Second, we remove the feature points of the floor surface using a histogram filter, and label the candidates of the obstacle extracted. Third, we estimate the location of obstacles based on motion vectors using LKOF. Finally, it estimates the robot position using an Extended Kalman Filter based on the obstacle position obtained by LKOF and creates a map. We will confirm the reliability of the mapping algorithm using motion estimation based on fisheye images through the comparison between maps obtained using the proposed algorithm and real maps.

• Physical Therapy Korea
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• v.22 no.3
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• pp.50-60
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• 2015

The purpose of this study was to apply the joint mobilization technique to the level of segments with pain and to the level of segments with hypomobility respectively and compare the immediate effects of the joint mobilization technique on the pain, the active cervical range of motion (ROM), and treatment satisfaction of patients with acute mechanical neck pain. After the baseline assessment, forty-two patients were randomized into two groups: a painful group ($n_1=21$) that received joint mobilization at the most painful cervical spine level and a hypomobile group ($n_2=21$) that received joint mobilization at the most hypomobile cervical level. The patients received an intervention that applied unilateral posterior-anterior gliding for 5 minutes and two repetitions of 10 times of active extension motion with distraction. In the Wilcoxon signed-rank test, the painful group and the hypomobile group were improved significantly in all pain variables (p<.001), while the painful group was improved significantly in the active cervical flexion (p<.001), extension (p<.001), left side-bending (p<.01), right side-bending (p=.001), left rotation (p<.001), and right rotation (p<.001). The hypomobile group was significantly improved in active cervical flexion (p=.001), extension (p<.001), left side-bending (p<.05), right side-bending (p=.001), left rotation (p=.001), and right rotation (p<.01) after intervention. In the Mann-Whitney U test, there was no significant difference in any of the dependent variables after the intervention between the two groups, but the painful group was slightly superior to the hypomobile group in all variables except for the right lateral flexion ROM and treatment satisfaction. These outcomes suggest that the cervical joint mobilization may be applied to either the level of painful segments or the hypomobile segments for the treatment of patients with acute mechanical neck pain.

• Journal of the Korean Institute of Navigation
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• v.23 no.2
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• pp.29-42
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• 1999

An accurate method of estimating ship maneuverability needs to be developed to evaluate precisely and improve the maneuverability of ships according to the water depth. In order to estimate maneuverability by a mathematical model. The hydrodynamic forces acting on a ship hull and the flow field around the ship in maneuvering motion need to be estimated. The ship speed new the berth is very low and the fluid flow around a ship hull is unsteady. So, the transient fluid motion should be considered to estimate the drag force acting on the ship hull. In the low speed and short time lateral motion, the vorticity is created by the body and grow up in the acceleration stage and the velocity induced by the vorticity affect to the body in deceleration stage. For this kind of problem, CFD is considered as a goof tool to understand the phenomena. In this paper, the 2D CFD code is used for basic consideration of the phenomena to solve the flow in the cross section of the ship considering the ship is slender and the water depth is large enough. The flow fields Added and hydrodynamic forces for the some prescribed motions are computed and compared with the preliminary experiment results. The comparison of the force with measurement is shown a fairly good agreement in tendency. The 3D Potential Calculation based on the Hess & Smith Theory is employed to predict the surge, sway added mass and yaw added moment of inertia of hydrodynamic coefficients for M/V ESSO OSAKA according to the water depth. The results are also compared with experimental data. Finally, the sway added mass of hydrodynamic coefficients for T/S HANNARA is suggested in each water depth.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.861-872
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• 2011

Many fast block-matching algorithms (BMAs) in motion estimation field reduce computational complexity by screening the number of checking points. Although many fast BMAs reduce computations, sometimes they should endure matching errors in comparison with full-search algorithm (FSA). In this paper, a novel fast BMA for constrained one-bit transform (C1BT)-based motion estimation is proposed in order to decrease the calculations of the block distortion measure. Unlike the classical fast BMAs, the proposed algorithm shows a new approach to reduce computations. It utilizes the binomial distribution based on the characteristic of binary plane which is composed of only two elements: 0 and 1. Experimental results show that the proposed algorithm keeps its peak signal-to-noise ratio (PSNR) performance very close to the FSA-C1BT while the computation complexity is reduced considerably.

• Korean Journal of Rural Living Science
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• v.5 no.2
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• pp.93-106
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• 1994

The purpose of this study was to develop the pattern of bodysuit and to identify the wear fitness of it The methods of statistical analysis applied to the study were ANOVA and cluster analysis. The materials used in making bodysuit were Nylon/Polyurethane, lace, power net, binding tape, and hook eye. The try-on test was administered in two aspects ; (1) the comparison of anthropometric data before and after trying on the experimentally constructed bodysuit with those of marketing bodysuit, (2) the sensory evaluation to estimate the wear fitness in terms of appearance and motion function. The conclusions obtained are as follows ; 1. In the survey of wearing state, 52.2% of respondents had experience of wearing bodysuit. 60.6% of them responded to the item, “well-balanced body” in the question about the purpose of wearing it. 55.7% considered the item, “feel choky in the chest” as uncomfortable point in putting on bodysuit. 48.3% felt the portion of crotch drawn above in taking exercise or behaving routinely in everyday life. 2. As for the characteristics of the bodysuit design, the scooped neckline and horizontal outline without wire in lower bust was used, the adjust point being located right above the perineum point, and the length of bodysuit is as far as trochanteric point. 3. In comparing anthropometric data of the subjects, there was significant difference in the height of lower bust the distance around abdomen, and the length of bust point(right, left) between the experimentally constructed bodysuit and the marketing bodysuit. 4. Concerning the results of the try-on test in appearance, the estimates of expert panel, which were in agreement with those of subjects in mean value and composite reliability coefficient, showed that the pattern fitness of experimentally designed bodysuit was higher than that of marketing bodysuit. 5. To take try-on test in motion function, motion was classified the five steps. The results of the test showed that experimentally designed bodysuit was fitter in each steps of motion than marketing bodysuit.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.353-361
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• 2015

Objective : The aim of this study was to develop the non-powered horse riding device and was to evaluate the elaborate its applicability throughout static structural and transient structural analysis of the outdoor core strength exercise equipment. Method : Fifteen college students (mass: $69.55{\pm}13.38kg$, height: $1.69{\pm}5.61m$, age: $21.42{\pm}1.83yrs$) rode the powered horse riding device and 14 college students (mass: $71.12{\pm}9.74kg$, height: $1.73{\pm}3.31m$, age: $22.50{\pm}1.47yrs$) rode the non-powered horse riding device for the comparison. All motion capture data was collected at 100 Hz using six infrared cameras and the muscular activities were collected using a Delsys Trigno wireless system. The peak forward/backward lean angle, range of motion anter/posterior and vertical COM(Center of mass) movement of trunk and pelvis segment, and muscle activities of six muscles were compared between the two devices by using independent t-test (p<.05). Results : Several kinematic variables (peak forward-backward lean angle and vertical COM movement of trunk and pelvis segment, range of motion of trunk) significantly different between non-powered and powered horse riding device. The muscle activities of Rectus abdominis and External oblique of abdomen on the non-powered horse riding device were significantly greater than those of the powered device. Conclusion : It was concluded that non-power horse riding device could give the effect of core strength exercise as well as the body motion which can simulate the powered horse riding device.

• PNF and Movement
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• v.17 no.3
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• pp.431-439
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• 2019

Purpose: This study investigated the effects of motion taping on muscle stiffness, muscle tone, and pain in middle-aged women with shoulder impingement syndrome. Methods: The participants comprised 30 middle-aged women with shoulder impingement syndrome. This study measured muscle stiffness, muscle tone, and pain. In the experimental group, the tape was attached after physical therapy; the control group only received physical therapy. In the intervention period, the treatment program was conducted three times a week for a total of four weeks, and the values before and after the intervention were compared and analyzed. For statistical processing, a correspondence test was performed before and after the intervention at a significance level of 0.05, and the comparison between the groups, before and after the intervention, was made using an independent test. Results: In the experimental group, there was a difference in muscle stiffness, muscle tone, and intensity of pain. In addition, there was a significant difference between the control group's emotional domain regarding muscular stiffness and pain and the experimental group. However, there was no significant difference in muscle tone and grade of pain, and intensity of pain for the control group. Conclusion: This study showed that, when physical therapy and motion taping were administered to middle-aged women with shoulder impingement syndrome, it had a more positive affect on the sensory and emotional parts of the muscle tone and pain compared to physical therapy alone.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.11
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• pp.137-146
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• 2015

In this paper, we propose a pothole detection method using various features of intensity and motion. Segmentation, decision steps of pothole detection are processed according to the values which are derived from feature characteristics. For segmentation using intensity, we use a binarization method using histogram to separate pothole region from background. For segmentation using motion, we filter using high pass filter and get standard deviation value. This value is divided by regression value according to camera environment such as photographing angle, height, velocity, etc. We get binary image by histogram based binarization. For decision, candidate regions are decided whether pothole or not using comparison of candidate and background's features. Experimental results show that our proposed pothole detection method has better results than existing methods and good performance in discrimination between pothole and similar patterns.