• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.363-368
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• 2005

This paper proposes an LOS(line-of-sight) guidance system of a ship for path following. From the viewpoint of a control configuration, guidance is a special type of compensation algorithm that is placed in front of the controller to accomplish navigational objects. A guidance system generates a reference trajectory for trajectory tracking or path control and decides the desired velocity, position and heading angle. A control system executes commands based on a reliable guidance law during navigation. An LOS vector from the vessel to a point on the path between two way-points in straight-line navigation or a point among turning circle in turning navigation is selected, and then a heading angle is calculated to converge the desired path based on the LOS vector. The LOS guidance law is defined for the straight-line and the turning circle, respectively. The effectiveness of the suggested LOS guidance system is assured through computer simulation.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.116-120
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• 2003

To study the trafficability on soft and cohesive benthic terrain, a tracked vehicle model($670mm(L){\times}750mm(B_c)$) is designed and tested. The pitch and chevron angle of grouser, weight and center of gravity of vehicle, and drawbar pull force are chosen as experimental variables. Slip, sinkage and inclined angle of vehicle are picked as performance values. Strength of soil is considered as noise factor. A preliminary straight-line motion test is performed. Then, DOE(Design of Experiment) is discussed for further research.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.1
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• pp.5-11
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• 2015

Background: The purpose of this study was to investigate the effects of Mulligan's straight leg raise with traction technique and hold-relax technique on flexibility of hamstring in people with shortened hamstring. Methods: Thirty two subjects participated in this study. The subjects were assigned to either the Mulligan's straight leg raise with traction technique group (n=16) or the hold-relax technique group (n=16). 90-90 straight leg raise test was performed for evaluation of hamstring shortening at initial time of study. After intervention, immediate effect (immediately after intervention) and lasted effect (60 min after intervention) were assessed. Results: In the both Mulligan's straight leg raise with traction technique and hold-relax technique groups, significant improvements on flexibility of hamstring was observed in immediately and 60 minute after intervention (p<.05). However, there are no significant difference was observed between groups (p>.05). Conclusion: In the results of this study, both Mulligan's straight leg raise with traction technique and hold-relax technique show immediately and 60 minute after evaluation effectiveness in flexibility of hamstring of people with shortened hamstring. In addition, although the difference is not statistically significant, Mulligan's straight leg raise with traction technique was more increased average extension angle of knee joint at 90-90 straight leg raise test than the hold-relax technique.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.554-559
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• 2003

A newly developed contact angle measurement instrument by laser beam projection allows for rapid and direct determination of contact angles. The instrument may have a possibility to characterize newly developed nano-fibers. When the laser beam impinges on an edge of an interface of liquid and solid, projected beam were split across and made two straight lines on a tangent screen. From the result, it could measure the contact angle directly by reading the angle between two split beams. The purpose of this study was to prove reliability and reproducibility of the contact angle measurement instrument by laser beam projection compare to the conventional one by microscope through the comparative experiment and questionnaire. Test samples were selected by consideration of hydrophilic and hydrophobic, such as nylon 6 and polypropylene, respectively. The laser contact angle measurement has accurate, fast and convenient method to measure contact angle, and it can be a unique method to characterize nano-fibers.

• The Journal of Korea CHUNA Manual Medicine
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• v.5 no.1
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• pp.151-161
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• 2004

Objectives : To investigate and compare the curvature of the cervical spine of the patients with whiplash and insidious onset neck pain. Method : Clinical study carried out in 33 insidious onset neck pain outpatients and 34 whiplash onset neck pain inpatients in Conmaul Oriental Hospital. Cervical spine curvature was measured using five measuring Methods. Type of cervical spine curvature was analyzed by Jochumsen method. Ishihara Index. T-test was used to compare the cervical spine angle of the two groups. Results : The prevalence of 'straight' and 'kyphotic' cervical spines was 46.5% in the insidious onset cases and 26.47% in the whiplash onset cases. In Jackson's angle, Jochumsen method, Ishihara Index, and Park's method, angle of the Cervical spine curvature was significantly lower in the insidious onset cases. (P<0.01) Conclusion : The results suggest that the cervical spine of neck pain patients is 'straight' and 'kyphotic' and more significant in insidious onset cases.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.892-896
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• 2011

This paper describes a camera-based position measurement system for automatic tracking control of a rubber Tired Gantry Crane (RTGC). An automatic tracking control of RTGC depends on the ability to measure its displacement and angle from a guide line that the RTGC has to follow. The measurement system proposed in this paper is composed of a camera and a PC that are mounted on the right upper between front and rear tires of the RTGC's side. The measurement accuracy of the system is affected by disturbances such as cracks and stains of the guide line, shadows, and halation from the light fluctuation. To overcome the disturbances, both side edges of the guide line are detected as two straight lines from an input image taken by the camera, and parameters of the straight lines are determined by using Hough transform. The displacement and angle of the RTGC from the guide line can be obtained from these parameters with the robustness against the disturbances. From the experiments with the disturbances, we found the accurate displacement and the angle from the guide line that have the standard deviations of 0.95 pixels and 0.22 degrees, respectively.

• Journal of the Korean housing association
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• v.20 no.5
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• pp.9-21
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• 2009

This study classified visual perception types of access space at 17 five-star hotels in Jejudo and examined their cognitive characteristics and image formation structures in an effort to provide basic information important for designing the elevation and the access spaces of a hotel. The results of this study are as follows. Access space image of experimental hotels showed more negative evaluations at both city hotels and resort hotels, viewing angle (upward angle) was also positively evaluated between $10^{\circ}{\sim}12^{\circ}$ and $18^{\circ}$ and central type in arrangement type and detour access and straight access types in access circulation type were positively evaluated. When viewed from an upward angle of $10^{\circ}$ to $12^{\circ}$, the most important factors were as plasticity, decorativeness, and creativity; from $18^{\circ}$ it was such factors as harmony and peculiarity; and at $45^{\circ}$ it was factors like decorativeness and stability. In considering the various access types, the most important factors in a straight access type were peculiarity and harmony; for one-time curved access type it was by decorativeness, creativity, Peculiarity, and stability; and for detour access types it was decorativeness, stability, and peculiarity. Influential of factors affecting image formation and plasticity and harmony factors and the form had more influences on image formation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.11
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• pp.863-869
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• 2008

This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. This new calibration algorithm was used for velocity data reduction from the calibration map and based on the combination of a look-up, a binary search algorithm and a geometry transformation including the translation and reflection of nodes in a calibration map. The calibration map was expanded up to the application angle, ${\pm}55^{\circ}$ of a probe. This velocity data reduction method showed a perfect performance without any kind of interpolating errors in calculating yaw and pitch angles from the calibration map. Moreover, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.2
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• pp.113-117
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• 2014

Laser Assisted Machining (LAM) was often used in process of difficulty-to-cut materials. In previous study, Laser assisted machining was a straight path processing using 1-axis manipulator in laser module. But 1-axis manipulator in laser module was able to process only straight path. So, in this study, laser module in laser assisted machining equipped to 2-axis manipulator. 2-axis manipulator has two motors. First motor is machining direction motor and second motor is Vertical Motor. Machining direction motor rotates in the direction of machining and vertical motor rotates vertical direction in the direction of machining. Machining path of laser assisted machining was considered diagonal path and curved path of laser heat source. This study calculated the 2-axis manipulator's rotation angle in diagonal path and curved path.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.159-170
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• 2005

The grid structure is parallel main girders intersected with crossgirder. It distribute the loads to adjoining main girder through the crossgirder when a girder is subjected to a load. grillage girder bridge has high load-carrying capacity, it can save materials and become more economical type of bridge. In this paper, the grillage girder bridge analysis program developed by using the transfer matrix method deals with following problems: the comparision with Leonhardt, Szabo, FEM yang and jung in the analysis of grillage girder bridges, quality of straight and curved bridges with skew angle, forces of straight and curved bridges according to skew angle and bending stiffness/torsional stiffness ratio.