• International Journal of Aeronautical and Space Sciences
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• 제14권2호
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• pp.152-161
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• 2013

This paper presents a control effectiveness analysis of the hawkmoth Manduca sexta. A multibody dynamic model of the insect that considers the time-varying inertia of two flapping wings is established, based on measurement data from the real hawkmoth. A six-degree-of-freedom (6-DOF) multibody flight dynamics simulation environment is used to analyze the effectiveness of the control variables defined in a wing kinematics function. The aerodynamics from complex wing flapping motions is estimated by a blade element approach, including translational and rotational force coefficients derived from relevant experimental studies. Control characteristics of flight dynamics with respect to the changes of three angular degrees of freedom (stroke positional, feathering, and deviation angle) of the wing kinematics are investigated. Results show that the symmetric (asymmetric) wing kinematics change of each wing only affects the longitudinal (lateral) flight forces and moments, which implies that the longitudinal and lateral flight controls are decoupled. However, there are coupling effects within each plane of motion. In the longitudinal plane, pitch and forward/backward motion controls are coupled; in the lateral plane, roll and side-translation motion controls are coupled.

• 대한정형도수물리치료학회지
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• 제16권2호
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• pp.53-60
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• 2010

Purpose : Neck pain is commonly experienced by both adolescents and adults. The purpose of this study was to measure neck disability index(NDI) and the cervical range of motion(CROM) following spinal manipulation and mobilization techniques. Methods : Thirty participants(manipulation=15, mobilization=15) with mild neck disability volunteered for this study. It was used to measure NDI with NDI questionnaire and six motions(neck flexion and extension, left and right lateral flexion, left and right rotation) with the CROM instrument. Independent t-test and paired t-test were used to estimate NDI and CROM, and compared left with right motions. Results : A significant decrease in NDI were found after spinal manipulation and mobilization treatment(p<.05). A trend toward increase in all cervical motions(flexion, extension, left and right lateral flexion, left and right rotation), after interventions, were revealed(p<.05). The significant differences were not found on NDI and CROM between the group(p<.05). It was presented asymmetric motions in cervical lateral flexion(p<.05) before and after treatment. Conclusions : Our results suggest that manipulation and mobilization probably provide at least short-term benefits for patients with mild neck pain. It is needed to be studied the factors and preventive methods influencing the asymmetric cervical motion.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.998-1003
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• 2013

This study proposes an adaptive control algorithm for lateral motion of a UGV (Unmanned Ground Vehicle) using an NN (Neural Networks). The lateral motion of the UGV can be corrupted with various uncertainties such as side slip. In order to compensate the performance degradation of the UGV under various uncertainties, an NN-based adaptive control is designed by utilizing a virtual control concept. Since both the drift and input gain terms are uncertain, the proposed method adapts the whole terms related to the difference between the nominal and real systems. To avoid a singularity problem with the adaptive control, the affine property of the UGV dynamic model is utilized and the overall closed-loop stability is analyzed rigorously. Finally, numerical simulations using Carsim are performed to validate the effectiveness of the proposed scheme.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.49-57
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• 2007

This paper proposes a traction control system (TCS) that uses a sliding mode wheel slip controller and a PID throttle valve controller. In addition, a yaw motion controller (YMC) is also developed to improve lateral stability using a PID rear wheel steering angle controller. The dynamics of a vehicle and characteristics of the controllers are validated using a proposed full-car model. A driver model is also designed to steer the vehicle during maneuvers on a split ${\mu}$ road and double lane change maneuver. The simulation results show that the proposed full-car model is sufficient to predict vehicle responses accurately. The developed TCS provides improved acceleration performances on uniform slippery roads and split ${\mu}$ roads. When the vehicle is cornering and accelerating with the brake or engine TCS, understeer occurs. An integrated TCS eliminates these problems. The YMC with the integrated TCS improved the lateral stability and controllability of the vehicle.

• 한국임상보건과학회지
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• 제1권1호
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• pp.29-34
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• 2013

Purpose : This study was to investigate that tongue positions have effect on the cervical range of motion (ROM). Methods : 18 subjects, 20 to 25 years of age, were participated in this study. The tongue positions were neutral position, anterior protrusion, posterior protrusion, superior protrusion, inferior protrusion, left side protrusion and right side protrusion. The neck movements were right side flexion, left side flexion, right rotation and left rotation. The cervical range of motion measured by cervical range of motion instrument (CROM, C9266-49, USA). The changes were analyzed using the paired t-test. SPSSWIN (ver. 20.0) was used for data analysis and the significance level was chosen as ${\alpha}$=0.05. Results : In the lateral flexion, the angle of left lateral flexion increased in anterior protrusion(p<0.05) and right side protrusion(p<0.05) significantly. In the rotation, the angle of right rotation increased in anterior protrusion(p<0.05), posterior protrusion (p<0.05), superior protrusion(p<0.05), inferior protrusion(p<0.05), and left side protrusion (p<0.05) significantly. Conclusions : In conclusion, we found that the tongue positions affected some cervical movements.

• Structural Engineering and Mechanics
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• 제34권6호
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• pp.719-738
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• 2010

The aim of this paper concerns with the nonlinear analysis of cable-stayed bridges including the vibration effect of cable stays. Two models for the cable stay system are built up in the study. One is the OECS (one element cable system) model in which one single element per cable stay is used and the other is MECS (multi-elements cable system) model, where multi-elements per cable stay are used. A finite element computation procedure has been set up for the nonlinear analysis of such kind of structures. For shape finding of the cable-stayed bridge with MECS model, an efficient computation procedure is presented by using the two-loop iteration method (equilibrium iteration and shape iteration) with help of the catenary function method to discretize each single cable stay. After the convergent initial shape of the bridge is found, further analysis can then be performed. The structural behaviors of cable-stayed bridges influenced by the cable lateral motion will be examined here detailedly, such as the static deflection, the natural frequencies and modes, and the dynamic responses induced by seismic loading. The results show that the MECS model offers the real shape of cable stays in the initial shape, and all the natural frequencies and modes of the bridge including global modes and local modes. The global mode of the bridge consists of coupled girder, tower and cable stays motion and is a coupled mode, while the local mode exhibits only the motion of cable stays and is uncoupled with girder and tower. The OECS model can only offers global mode of tower and girder without any motion of cable stays, because each cable stay is represented by a single straight cable (or truss) element. In the nonlinear seismic analysis, only the MECS model can offer the lateral displacement response of cable stays and the axial force variation in cable stays. The responses of towers and girders of the bridge determined by both OECS- and MECS-models have no great difference.

• 한국전문물리치료학회지
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• 제27권1호
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• pp.70-77
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• 2020

Background: Neck pain can be caused by any structure in the neck, such as intervertebral discs, ligaments, muscles, facet joints, dura mater, and nerve roots. The hyoid bone is a structure that is also related to head and neck posture, neck movement and pain, but there are no studies on hyoid deviation, neck pain, and range of motion (ROM). Objects: The purpose of this study was to investigate the effect of fascia relaxation and mobilization of the hyoid bone on the ROM, pain, and lateral deviation of the hyoid bone. Methods: Twenty-five patients with neck pain identified by the lateral motion test (10 males [35.13 ± 7.67 years, 172.69 ± 3.90 cm, 78.77 ± 6.96 kg] and 15 females [35.13 ± 10.05 years, 161.11 ± 4.09 cm, 52.59 ± 2.98 kg]) was chosen randomly. Baseline values for pain, neck ROM, and lateral deviation in the hyoid bone were recorded using a visual analogue scale (VAS), goniometer, and tape measure. Then, each patient was treated with hyoid fascia relaxation and mobilization, and all results were recorded after intervention. Comparison of the results before and after intervention was analyzed using paird t-test (p < 0.05). Results: Right rotation, extension, VAS, and rotational asymmetry statistically significant differences (p < 0.05). Right rotation and extension increased ROM, rotational asymmetry ratio and VAS decreased. However, there was no significant difference in flexion, left rotation, center point (p > 0.05). Conclusion: Fascia relaxation and hyoid mobilization could improve the ROM of cervical extension, asymmetry of the cervical rotation and neck pain.

• 한국지능시스템학회논문지
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• 제25권2호
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• pp.168-173
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• 2015

비행 시 외부 조건에 따라 비선형시변 동적특성을 갖는 항공기의 비행제어는 종 제어(longitudinal control)와 횡 제어(lateral control)로 나눌 수 있으며, 종 제어는 승강키(elevator)에 의한 피치(pitch)값, 횡 제어는 에일러론(aileron)에 의한 롤(roll)값과 방향키(rudder)에 의한 요(yaw)값들을 제어대상으로 삼는다. 현재까지 항공기의 안정성, 조종성 그리고 기동성을 보장하기 위한 제어시스템 개발에 많은 연구들이 활발히 진행되어 왔으나, 최근에는 다양하고 복잡한 풍동실험과 환경실험들을 필요로 하는 기존연구들과는 다른 항공기의 지능제어시스템 개발에 관련된 연구들이 이루어지고 있다. 본 논문은 대표적인 지능제어방식인 Interval Type-2 퍼지논리기법에 의한 항공기 종 제어시스템을 제시하고 F-4 제트전투기의 컴퓨터 모의실험을 통해 그 효용성을 입증한다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1147-1156
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• 1993

In order to analyze lateral control in the backward maneuver of a tractor -trailer combination , a kinematic vehicle model and a human operator model with time delay were utilized for the operator/vehicle system. The analysis was carried out using the frequency domain approach. The open-loop stability of the vehicle motion was analyzed through the transfer functions. The sensitivity of the stability of the vehicle motion. to a change in the steering angle, was also analyzed. A mathematical model of the closed -loop operator/vehicle system was then formulated. The closed -loop stability of the operator /vehicle system was then analyzed. The effect of the delay time on the system was also analyzed through computer simulation.

• 한국기계연구소 소보
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• 통권15호
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• pp.5-17
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• 1985

Dynamics of railway vehicles are strongly influenced by the wheel/rail contact forces. Wheel/rail contact geometric characteristics are important parameters to determining wheel/rail contact forces. In general, geometric relations between wheel and rail are represented by nonlinear functions of the wheelset lateral excursion and the relative yaw angle. There are some analytical and experimental studies to show the influences of the wheelset lateral displacement on wheel/rail geometric relations. Recently radial steering bogie which is designed to have flexible yaw motions of wheelsets was developed to improve curve negotiation performance. The radial steering bogie makes it important problem to study the effects of wheelset yaw motion on wheel/rail geometric relations. This paper describes the method to analyze 3-dimensional wheel/rail contact geometry considering wheelset yaw motion and describes also some computer simulation results.