• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.29 no.1
• /
• pp.53-67
• /
• 2023

Background: This study comparatively evaluated the effects of equipment-based pilates exercises (EPE) and lumbar stability exercises (LSE) in patients with chronic low back pain in terms of their Visual Analogue Scale(VAS), Oswestry Disability Index(ODI), and abdominal muscle thickness. Methods: A total of 30 participants were recruited and randomly assigned to either the EPE or the LSE. The VAS, ODI, and abdominal muscle thicknesses of the participants were measured before and after the intervention. Results: The EPE were more effective in terms of the duration of a sustained reduction in VAS scores. post hoc test revealed that EPE were more efficacious in terms of a sustained improvement in ODI scores. With respect to changes in abdominal muscle thickness, there was a significant difference in the thickness of internal oblique muscles(IO) and the external oblique muscles(EO) between the two groups. Conclusion: In this study, both types of exercise interventions resulted in improvements in the VAS, ODI scores, and abdominal muscle thickness in patients with chronic low back pain. However, EPE were found to be more effective than LPE in terms of longer sustained improvements in VAS and ODI scores. Also, with respect to abdominal muscle thickness, the thickness of EO and IO improved only in the EPE group.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.5 no.2
• /
• pp.109-121
• /
• 1995

Reaction coulples of SiC with cobalt were annealed in an Ar/4 vol% $H_2$ atmosphere at temperatures between $950^{\circ}C$ and $1250^{\circ}C$for various times between 4 and 100 h. At temperatures above $950^{\circ}C$, solid state reactions lead to the formation of various silicides with carbon precipitates. The typical reaction layer sequence was $SiC/CoSi + C/CozSi + C/CozSi/CozSi + C/{\cdot\cdot\}/CO_2Si/CO$ in the reaction zone. The mechanism of the periodic band structure formation with the carbon precipitation behaviour was examined and discussed in terms of reaction kinetics and thermodynamic considerations. The growth of the reaction zone has a square root of time dependence. The reaction kinetics is proposed to estimate the effective reaction constant from the parabolic gowth of the reaction zone. The mechanical properties of the reaction zones were determined by the microhardness test.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.5 s.122
• /
• pp.415-426
• /
• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.7 no.2
• /
• pp.45-51
• /
• 2008

The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. In order to perform this objective, a upward and downward traverse unit in which a unit that consists of a motor and reducer, chain and sprocket wheel, and upper and lower base employed in an automatic object changer unit performs sliding contact motion in a frame was designed. To achieve this design, constraint conditions for the upward and downward traverse unit first designed. Then, an operation mechanism was designed and that was introduced as a sum of kinetic energy for the sprocket wheel and upper and lower base based on the moment of inertia, which is the kinetic energy of the converted upward and downward traverse unit in the side of the reducer. In addition, The work required to rotate the converted upward and downward traverse unit in the side of the reducer by one revolution can be calculated using the sum of work that is required in the sprocket wheel and upper and lower base that is a part of the upward and downward traverse unit. Furthermore, the converted equation of motion in the side of the motor can be introduced using the equation of motion using the converted upward and downward traverse unit in the side of the motor. Then, Then, a proper motor can be determined using predetermined specifications employed in the motor and several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. Also, a design of a horizontal traverse unit that performs sliding motion on a upward and downward traverse unit and simulation that verifies the results of this design are required as a future study.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.2
• /
• pp.159-164
• /
• 2011

In this study, a crab robot is implemented in H/W based on four-bar linkage mechanism and Jansen mechanism, and its kinematics is analysed. A vision camera is attached to the mechanism, which makes the proposed robot a kind of biologically inspired robot for image acquisition. Three ultrasonic sensors are adopted for obstacle avoidance. In addition, the biologically inspired robot can achieve the mission appointed by a programmer outside, based on RF and Blue-tooth communication module. For the design and implementation of a crab robot, it is need to get joint variable, a foot point, and their relation. Thus, the proposed kinematic analysis is very important process for the design and implementation of legged robots.

• Journal of Biomedical Engineering Research
• /
• v.24 no.4
• /
• pp.309-318
• /
• 2003

In this paper a 6 degree-of-freedom robot was studied for medical purpose. In the past the robot used for industry field was utilized for medical robot but in these days the robot used for rehabilitation. welfare, and service. This system was Proposed for a stroke patient or a patient who can not use one arm. A master-slave system was constructed to exercise either paralysis or abnormal arm using normal arms movement. Study on the human body motion result was applied to calculate a movement range of humans elbow and shoulder. In addition, a force-torque sensor is applied to estimate the rehabilitation extent of the patient in the slave robot. Therefore, the stability of the rehabilitation robot could be improved. By using the rehabilitation robot, the Patient could exercise by himself without any assistance In conclusion. the proposed system and control algorithm were verified by computer simulation and system experiment.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.1
• /
• pp.89-95
• /
• 2013

This study investigates a parallel manipulator that can move over two parallel sliders and in which the end-effector of the manipulator can be adjusted arbitrarily. Through the direct and inverse kinematics of the manipulator, position equations are derived. These equations represent the relationship between the positions of the sliders and the position of the end-effector. The Jacobian matrices of the direct and inverse kinematics are obtained by these equations. By using the condition number defined from these matrices, the local performance index of the manipulator is proposed. By using the simulation results of the performance index, we find that the manipulator can smoothen movements in only one quadrant and that the distribution of the maximal performance index is affected by the ratio of the length of links and the orientation of the end-effector.

• The Korean Journal of Archival Studies
• /
• no.48
• /
• pp.5-44
• /
• 2016

This paper examines the characteristics of the May 18th (5 18) Gwangju Democratization Movement archives to suggest a collection development strategy for the May 18th archives collection network. Individual public and civilian archives collecting the May 18th archives separately should form a cooperative collection network based on documentation strategy. Most of all, May 18th archives are human rights records and should be understood and collected as human rights records. International principles support the collection of the May 18th archives as human rights archives by prohibiting destruction of relevant temporary records and encouraging the victims' right to access to their records. As the May 18th archives were mostly produced by many multiple agencies, this multi-provenance and diversity of the records necessitate the building of an archives portal for the records registries and online search. To document the undocumented past and the victims, the collection network should focus on oral history project as a major part of its collection development strategy. Finally, the May 18th archives collection network should build a cooperative relations with the unwilling public agencies which have the archives holdings. Therefore, the collection development strategy should include advocacy and awareness activities for promoting cooperation from these public agencies and public archives, and the people in general.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.5
• /
• pp.116-122
• /
• 2014

In this study, 2 kinds of twist run models as exercise equipments are compared by durability analyses of fatigue and vibration. Maximum equivalent stresses are shown as 3.3 MPa and 16.6 MPa at the parts of stress concentrations at models 1 and 2. As the values becomes much lower than yield stress of this models, these models are shown to be safe designs. Model 1 becomes stronger than model 2 at natural frequency analysis. Fatigue lives become lowest at four axis parts and one axis part respectively in cases of models 1 and 2. Maximum damage probability at fatigue is shown to be 2.4% near the average stress of 0 in case of model 1 but this probability becomes 0.6 % in case of model 2. Model 1 has the maximum damage possibility 4 times more than model 2 at these states. As the result of this study is applied by the design of twist run, the prevention on fatigue damage and the durability are predicted.

• Journal of Biomedical Engineering Research
• /
• v.25 no.4
• /
• pp.277-282
• /
• 2004

In order to investigate the small female occupant behavior and accompanying injury mechanisms in vehicular trash event, a finite element model of $5^{th}$ percentile female has been developed. The model consists of articulated rigid body, which represents the morphology of small female body, and internal components with anatomical details. Articulated rigid body model serves as a basic platform for joining the detail internal skeletons and organs, while itself can be used for representing the overall kinematics of small female occupant. The modeling details such as anthropometry and finite element structure as well as validation results for the articulated rigid body model are introduced in this paper. The second part of the modeling, i.e. the internal components with anatomical details of small female are presented in subsequent part II of the paper.