• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1137-1146
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• 1993

In order to analyze lateral control in the forward manuever of a tractor- trailer combination , a human operator model and a kinematic vehicle model were utilized for the operator/vehicle system. By combining the vehicle and operator models, a mathematical model of the closed-loop operator/vehicle system was formulated. A computer program was developed so as to simulate the motion of the tractor-trailer combination . In order to verify the operator/vehicle system model, the results of the field trials were compared with the simulated results. There was found to be reasonably good agreement between the two.

• PNF and Movement
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• v.15 no.2
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• pp.159-166
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• 2017

Purpose: This study attempts to determine the effects of applying three kinds of breathing exercises for four weeks on the neck muscle activation of subjects with a forward head posture. Methods: A total of 30 adults aged in their twenties (15 men and 15 women) with a forward head posture who voluntarily agreed to participate after listening to the purpose and procedure of this research were chosen as the subjects of this study. The subjects were randomly divided into either the diaphragmatic breathing exercise (DBE) group, the abdominal drawing-in maneuver (ADIM) group, or the abdominal expansion method (AEM) group according to the breathing intervention scheme. Each group included ten subjects. The muscle activity of the sternocleidomastoid, scalenus anterior, and splenius capitis was measured in all the groups prior to the intervention, two weeks after the intervention, and four weeks after the intervention. All the interventions were implemented for 30 minutes a day, three times a week, for a total of four weeks. Results: No significant between-group difference was observed in terms of the change in neck muscle activity according to the four-week intervention scheme. Further, there was no interaction between the intervention period and the intervention scheme in relation to the change in neck muscle activity. Conclusion: The results of this study suggest that abdominal expansion exercise is as effective as other breathing exercise methods for subjects with a forward head posture. We therefore expect that abdominal expansion exercise can be used as a scheme for the prevention of symptoms as well as therapy for patients with a forward head posture.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.122-131
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• 2004

A constraint equation-based control law design for large angle attitude maneuvers of flexible spacecraft is addressed in this paper The tip displacement of the flexible spacecraft model is prescribed in the form of a constraint equation. The controller design is attempted in the way that the constraint equation is satisfied throughout the maneuver. The constraint equation leads to a two-point boundary value problem which needs backward and forward solution techniques to satisfy terminal constraints. An observer-based tracking control law takes the constraint equation as the input to the dynamic observer. The observer state is used in conjunction with the state feedback control law to have the actual system follow the observer dynamics. The observer-based tracking control law eventually turns into a stabilized system with inherent nature of robustness and disturbance rejection in LQR type control laws.

• Physical Therapy Korea
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• v.22 no.1
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• pp.37-48
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• 2015

This study aimed to investigate the effect of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) on trunk stabilization, as well as trunk muscle activities and differences in quadruple visual analogue scale, Korean Oswestry Disability Index, and Fear Avoidance Beliefs Questionnaire scores, in patients with chronic low back pain and lumbar spine instability. To increase intra-abdominal pressure during the trunk stabilization exercise, the technique of pushing the abdomen out using diaphragmatic abdominal breathing suggested by Pavel Koral was used, which we termed the AEM. Fifty patients who tested positive on more than three of the five lumbar spine instability tests were separated from 138 patients with chronic low back pain of these patients, 16 were placed in the control group (trunk stabilization exercise), 17 were placed in the ADIM group (trunk stabilization exercise with ADIM), and 17 were placed in the AEM group (trunk stabilization exercise with AEM). Each group participated in the study for 30 minutes three times weekly for 4 weeks. Surface electromyography was used to measure the trunk muscle activities during the kneeling forward and supine bridging positions, and one-way repeated analysis of variance was used to determine the statistical significance of the trunk muscle activities in the rectus abdominis, internal oblique (IO), erector spinae, and multifidus (MF) muscles. The ADIM and AEM groups showed relatively larger improvements in psychosocial and functional disability level than control group. There were significant changes among the three groups, those from the measured values of the AEM group was significantly higher than the other two groups in changes in IO and MF trunk muscle activities (p<.05). This finding demonstrates that trunk stabilization exercises with AEM is more effective than ADIM for increasing trunk deep muscle activity of chronic low back pain patients with lumbar spine instability.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.3
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• pp.51-61
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• 2014

In this paper, we deal with developing a cost estimation relationships (CER) for Korean maneuverable weapons systems using historical production cost. To develop the CER, we collected the historical data of the production cost of four tanks and five armored vehicles. We also analyzed the Required Operational Capability (ROC) of the weapons systems and chose cost drivers that can compare operational capabilities of the weapons systems We used Forward selection, Backward selection, Stepwise Regression and $R^2$ selection as the cost drivers which have the greatest influence with the dependent variables. And we used Principle Component Regression, Robust Regression and Weighted Regression to deal with multicollinearity and outlier among the data to develop a more appropriate CER. As a result, we were able to develop a production cost CER for Korean maneuverable weapons systems that have the lowest cost errors. Thus, this research is meaningful in terms of developing a CER based on Korean original cost data without foreign data and these methods will contribute to developing a Korean cost analysis program in the future.

• International Journal of Automotive Technology
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• v.8 no.4
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• pp.445-453
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• 2007

This paper presents a robust controller design approach for improving vehicle dynamic roll motion performance and guaranteeing the closed-loop system stability in spite of vehicle parameter variations resulting from aging elements, loading patterns, and driving conditions, etc. The designed controller is linear parameter-varying (LPV) in terms of the time-varying parameters; its control objective is to minimise the $H_{\infty}$ performance from the steering input to the roll angle while satisfying the closed-loop pole placement constraint such that the optimal dynamic roll motion performance is achieved and robust stability is guaranteed. The sufficient conditions for designing such a controller are given as a finite number of linear matrix inequalities (LMIs). Numerical simulation using the three-degree-of-freedom (3-DOF) yaw-roll vehicle model is presented. It shows that the designed controller can effectively improve the vehicle dynamic roll angle response during J-turn or fishhook maneuver when the vehicle's forward velocity and the roll stiffness are varied significantly.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.239-248
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• 2022

Forestry crane work in a forest harvester or forwarder is regarded as one of most hard work requiring a very high level of operation skill. The operator must handle two or more multi-axes joysticks simultaneously to control the multiple manipulators for maneuvering the crane-tip to its intended location. This study has been carried out to develop a crane-tip controller which can intuitively maneuver the crane-tip, resulting in improving the productivity by decreasing the technical difficulty of control as well as reducing the workload. The crane-tip controller consists of a single 2-axis joystick and a control algorithm run on microcontroller. Lab-scale forestry crane was constructed using electric cylinders. The crane-tip control algorithm has the crane-tip follow the waypoints generated on the given path considering the dead band region using LBO (Lateral Boundary Offset). A speed control gain to change the speed of relevant cylinders relatively is applied as well. By the P (Proportional) control within the control interval of 20 msec, the average error of crane-tip control on the predefined straight path turned out to be 14.5 mm in all directions. When the joystick is used the waypoints are generated in real time by the direction signal from the joystick. In this case, the average error of path control was 12.4 mm for straight up, straight forward and straight down movements successively at a certain constant speed setting. In the slant movement of crane-tip by controlling two axes of joystick simultaneously, the movement of crane-tip was controlled in the average error of 15.9 mm when the crane-tip is moved up and down while moving toward forward direction. It concluded that the crane-tip control was possible using the control algorithm developed in this study.

• Journal of Advanced Navigation Technology
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• v.9 no.2
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• pp.185-192
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• 2005

The aim of this paper is to analyze handling qualities of tiltrotor aircraft(TR-S4) in helicopter flight mode including hovering and forward flight. Analysis of handling qualities is composed of aircraft response to control inputs that effect on stability and controllability. In short term response analysis, bandwidth is the critical parameter for small amplitude motions since it relates to the ability of a pilot to crisply start and stop maneuver. The handling qualities of TR-S4 in helicopter mode are analyzed with a SAS and an attitude controller and are satisfied level 1 in almost criteria with simulation of TR-S4 6-DOF nonlinear model.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.440-443
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• 2022

Spinal accessory nerve (SAN) palsy is typically a result of posterior triangle surgery and can present with partial or complete paralysis of the trapezius muscle and severe shoulder dysfunction. We share an atypical case of a patient who presented with SAN palsy following an injury sustained playing competitive volleyball. A 19-year-old right hand dominant competitive volleyball player presented with right shoulder weakness, dyskinesia, and pain. She injured the right shoulder during a volleyball game 2 years prior when diving routinely for a ball. On physical examination she had weakness of shoulder shrug and a pronounced shift of the scapula when abducting or forward flexing her shoulder greater than 90 degrees. Manual stabilization of the scapula eliminated this shift, so we performed scapulopexy to stabilize the inferior angle of the scapula. At 6 months postoperative, she had full active range of motion of the shoulder. SAN palsy can occur following what would seem to be a routine volleyball maneuver. This could be due to a combination of muscle hypertrophy from intensive volleyball training and stretch sustained while diving for a ball. Despite delayed presentation and complete atrophy of the trapezius, a satisfactory outcome was achieved with scapulopexy.

• Journal of Acupuncture Research
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• v.18 no.4
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• pp.201-204
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• 2001

Objective : This study was to report a clinical trial in which acupuncture treatmnt on 會陰(Huiyin, CV1) was effectively applied to a patient who had suffered from teasing pruritus ani for 38 years. pruritus ani was thought to be initiated by dystonia. Methods : The acupoint, 會陰(Huiyin, CV1) was selected, because needling on perineal muscles was mainly used to alleviate pelvic pain or pruritus ani in the light of MPS(Myofascial Pain Syndrome) theory, on which 會陰(Huiyin, CV1) was located and also had pelvic pain and pruritus ani in its indications. On the acupoint, the following maneuver was used. (1) Make a patient stand and bend forward (2) Insert a needle on 會陰(Huiyin, CV1) (3) Repeat lifting and pushing (4) Draw a needle immediately without retaining needle on the acupoint Results : The patient with Pruritus ani recovered after above treatment two times and had no recurrence up to Feb. 2001. Conclusion : In this study, Needling on 會陰(Huiyin, CV1) proved to be effective in the aspect of MPS and acupuncture treatment as well, but more clinical trials are expected to follow this study.