• The Journal of Korean Physical Therapy
• /
• v.35 no.3
• /
• pp.64-70
• /
• 2023

Purpose: This study investigated the influence of attention-demanding tasks on gait and measured differences in the temporal, spatial and kinematic characteristics between young healthy adults and elderly healthy adults. Methods: We recruited 16 healthy young adults and 15 healthy elderly adults in this study. All participants performed two cognitive tasks: a subtraction dual-task (SDT) and working memory dual-task (WMDT) during gait plus one normal gait. Using the LEGSys+ system, knee and hip-joint kinematic data during stance and swing phase and spatiotemporal parameter data were assessed in this study. Results: In the elderly adult group, attention-demanding tasks with gait showed a significant decrease in hip-joint motion during the stance phase, compared to the normal gait. Step length, stride length and stride velocity of the elderly adult group were significantly decreased in WMDT gait compared to normal gait (p<0.05). In the young adult group, kinematic data did not show any significant difference. However, stride velocity and cadence during SDT and WMDT gaits were significantly decreased compared to those of normal gait (p<0.05). Conclusion: We determined that attention-demanding tasks during gait in elderly adults can induce decreased hip-joint motion during stance phase and decreased gait speed and stride length to maintain balance and prevent risk of falling. We believe that understanding the changes during gait in older ages, particularly during attention-demanding tasks, would be helpful for intervention strategies and improved risk assessment.

• Journal of muscle and joint health
• /
• v.20 no.2
• /
• pp.141-150
• /
• 2013

Purpose: This study was conducted to identify relationships among nursing activities, the use of body mechanics, and job stress in nurses with low back pain. Methods: Participants were 225 nurses with low back pain working at an university hospital. The data were collected with self-reported questionnaires at March, 2012 and analyzed by descriptive statistics, t test, ANOVA, Scheff$\acute{e}$e test and multiple regression analyses. Results: There was significantly a higher degree of pain in subjects who working at special units including intensive care units and emergency room than at general wards. Low back pain was negatively correlated with the use of body mechanical principles while it was positively associated with the degree of job stress. According to results of multiple regression analyses, low back pain was significantly associated with the use of body mechanics and job stress in nurses working at general ward and special units including intensive care units and emergency room. Conclusion: The use of the principles of body mechanics and reducing job stress are important to prevent low back pain in nurses. It is necessary to develop and apply stress management and education program about the use of the principles of body mechanics.

• Journal of muscle and joint health
• /
• v.25 no.3
• /
• pp.196-204
• /
• 2018

Purpose: The purpose of this study was to contribute to the activation of comprehensive nursing care services by comparing and analyzing the working environment and operational status of comprehensive nursing care wards with general wards. Methods: A questionnaire survey was conducted at hospitals operating comprehensive nursing care services. We collected data on patient characteristics, workforce, working environment, and work support facilities of 40 hospitals voluntarily participating in the survey. The collected data were analyzed by dividing it into an comprehensive nursing care ward and a general ward. Results: Compared with the general ward, the comprehensive nursing care ward had fewer hospitalized patients, but the severity of the patients and the need for nursing were high. The number of nurses, assistant nurses, and ward support workers per patient was higher in the comprehensive nursing care ward than in the general ward, and the implementation rate of night shift fixed system, the fixed shift system, and the preceptor system were higher. In terms of structural environment, comprehensive nursing care wards had more room for interviews. Conclusion: The comprehensive nursing care ward had more nursing staff and provided a better working environment than the general ward, but required additional support for the structural environment.

• Journal of muscle and joint health
• /
• v.30 no.2
• /
• pp.138-146
• /
• 2023

Purpose: The purpose of this study was to examine knowledge, health beliefs and health promoting behavior about osteoporosis in working women in their 20s and 30s. Methods: A survey was conducted among working women in their 20s and 30s who visited the health promotion center of B Medical Center in B Metropolitan City. The data were collected from December 2021 to March 2022 using structured self-reported questionnaires. SPSS/WIN 25.0 program was used to analyze the data. Results: Factors influencing health promoting behavior about osteoporosis in women in their 20s and 30s were in the order of "good" subjective health status (β=.47, p<.001), "moderate" subjective health status (β=.36, p<.001) and knowledge (β=.18, p=.015). These factors explained 12.4% of health promoting behaviors about osteoporosis. Conclusion: The results indicate the need to develop and implement healthcare programs that can improve the health status and provide knowledge to improve health promoting behavior about osteoporosis in women in their 20s and 30s.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.2
• /
• pp.57-67
• /
• 2005

The purpose of this study was to analyze the kinetic factors of the golf driver swing using the Inverse Dynamics function. For this purpose, joint force were calculated. In order to test the possibility of Inverse Dynamics function(motion-dependent interaction), a triple segmental system was set for wrist, left shoulder and lumbar and joint force working on the anatomical joint region was estimated. For this study, 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint force and torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint force was generated on wrist, shoulder and lumbar joints in the direction of the target, and that the joint force was stronger in the direction of target immediately before impact. The joint force was generated towards the target to activate the nodes, and then, it was generated in the reverse direction to increase the speed during impact.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.3
• /
• pp.25-31
• /
• 2016

Gaskets are usually used for the sealing of flange joints. The joint is usually composed of two flanges, a ring gasket and clamping bolts. The metal ring gasket is suitable for pipe flanges, pumps and valve joints in high temperature and high pressure environments. A very high surface stress is developed between a ring type joint gasket and the flange groove when the ring type joint is bolted up in a flange. The dimensions of flanges and ring joint gaskets for the pipe sizes that are in common use are specified in the ANSI codes. However, sometimes it is necessary to make a new design for the flange joint which is not specified in the codes, as the equipment is getting larger and larger in size. This paper presents the contact behavior of Class 600 ring joint gaskets with oval and octagonal cross sections. Five different sizes of gaskets are employed in the analysis, and one of them is newly designed on the basis of analysis results obtained from existing models. Three load steps are used to find the stress, stain and contact pressure etc., and to compare the contact characteristics among the models due to the bolt clamping force and the working surface pressure. ANSYS Workbench version15 is used to conduct the finite element analysis.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.8 no.6
• /
• pp.584-590
• /
• 1984

This study is to develop a program, with which the motion of the system can be simulated in view of kinematics and dynamics, and then evaluate functional capabilities of many robots in order to select the most suitable one for any given working conditions. According to the theory of Denavit & Hartenberg, rectangular coordinate is set at each joint in the robot of six joints, as this one is the major concern, and transformation matrices are derived between any two coordinates. The necessary displacement of each joint for executing a given a work is obtained from the position and posture transformation and the in-stantaneous velocity of the joint is got from given velocity distribution of the path. The necessary torque of each joint is finally calculated by Newton-Euler Method. This simulation program is applied to a robot with six rotational joints, Rotational angle and torque to time which has a given motion trajectory are figured and also torque to r.p.m.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.32 no.2
• /
• pp.141-147
• /
• 2007

We consider a GI/M/1 queue with vacations such that the server works with different rate rather than completely stops working during a vacation period. We derive the transform of the joint distribution of the length of a busy period, the number of customers served during the busy period, and the length of the subsequent idle period.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.10a
• /
• pp.575-581
• /
• 1993

This paper deals with analysis of articulated robot manipulator used for Arc welding and Material handling. Compared with present robot of which weight holding capacity is 6kg, this robot shows wider and symmetric working range for it's serial type mechanism. The link length is determined to have widest working range by using optimal simulation. To reduce body's weight, small AC servo motor is adopted and driving peak torque exerted at each joint is reduced by using dynamic analysis. So it is possible to reduce body's weight by 40% compared with the same class's robot and get wider working range. And by adopting modular design concept, each axis is designed to be changed easily for user's special need and repair.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.75-79
• /
• 2002

A hydraulic Excavator is applied for outdoor tasks in construction, agriculture and undersea etc. When a hydraulic Excavator works crane function tasks, most of disasters happen. In this study, In order to preventing these disasters, the safety equipment algorithm for crane working is developed, and the safety equipment algorithm for crane working is being developed. The proposed control algorithm(Zero Moment Point) is designed to avoid overload. The hydraulic excavator for crane function must work within a maximum limit of load. To accurately detect a working load, pressure sensors of boom, arm cylinder, and angle sensors of boom, arm and bucket joint are used.