• Archives of Orthopedic and Sports Physical Therapy
• /
• v.14 no.2
• /
• pp.45-53
• /
• 2018

Purpose: The purpose of this study was to investigate the effects of muscle activity and muscle strength according to verbal command volume during isokinetic and isometric quadricep exercises. Methods: To measure muscle activity and muscle strength, surface electrodes were attached to the participants, as they sat on a Biodex chair. The isometric exercise was performed three times, with maximum exercise at $30^{\circ}$ bending angle, based on a maximum extension state of the knee at $0^{\circ}$. The average holding time was unified to three seconds. In addition, the isokinetic exercise was performed three times, at $60^{\circ}/sec$. The verbal command ranged between 0∾60 dB and 0∾75 dB. Muscle activity was measured using surface electromyography (4D-MT, Relive, Gimhae, Korea). The Biodex System 4 was used to measure the isometric and isokinetic strength of the nodal line, and 4D-MT was used to measure muscle activity. Results: There were significant improvements in the maximal and relative muscle strengths, when the 0∾ 60 dB and 0∾75 dB verbal commands were applied with isokinetic extension/flexion (p<.05). The isokinetic exercise (0∾75 dB) group showed a significant difference in the vastus medialis oblique muscle activity change (p<.05), while the isometric exercise (0∾75 dB) group showed a significant difference in the rectus femoris muscle activity change (p<.05). Conclusions: Our results reveal that verbal commands effectively improve muscle activity and muscle strength during isokinetic and isometric quadricep exercises.

• Korean Journal of Computational Design and Engineering
• /
• v.8 no.4
• /
• pp.254-261
• /
• 2003

In mold and die shops, NC machining process mainly affects the quality of the machined surface and the manufacturing time of molds and dies. The estimation of NC machining time is a prerequisite to measure the machining productivity and to generate a process schedule, which generally includes the process sequence and the completion time of each process. It is required to take into account dynamic characteristics in the estimation, such as the ac/deceleration of NC machine controllers. Intensive observations at start and end points of NC blocks show that a minimum feedrate, a key variable in a machining time model, has a close relation to a block distance, an angle between blocks, and a command feedrate. Thus, this study addresses regression models for the minimum feedrate estimation on short and long NC blocks considering these parameters. Furthermore, machining time estimation models by the four types of feedrate behaviors are suggested based on the estimated minimum feedrate. To show the validity of the proposed machining time model, the study compares the estimated with the actual machining time in the sculptured surface machining of several mold dies.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.389-394
• /
• 1991

The surface-to-air missile system using Command to Line-Of-Sight (CLOS) guidance law is represented by complex nonlinear differential equations with 6 degree-of-freedom. This paper presents the characterictics of missile system and the effect of various error sources by Monte-Carlo simulation method. By simulation the part of playing a main role in the surface-to-air missile system is radar. Therefore for the performance of missile system the development of the technique reducing the error of radar is required. And the effect of accelerometer error is a few large, too. But, because accelerometer costs cheap this problem is solved easily. And the main error source of missile system data is the thrust, which affects directly to acceleration. The result is the important information about designing and fabricating missile system. And this makes the missile system best because of sharing elaborate and expense effectively.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.2
• /
• pp.165-172
• /
• 2021

Purpose : This study was conducted to find out the effect on the activity of trunk and lower limbs muscles during abdominal drawing-in bridging exercises by verbal cue on the unstable supporting surface after pelvic rearward sloping taping for trunk stabilization movement. Methods : The study subjects were recruited by using the on-campus bulletin boards for healthy adult males and females in their 20s attending K University in Changwon-city, South Gyeongsang Province. The subjects were 30 persons (15 males and 15 females) who agreed to the study purpose in accordance with the criteria for selection and exclusion. Results : The results were obtained by measuring the muscle activity of the trunk and lower limbs during abdominal drawing-in bridging exercises by verbal cue on the unstable supporting surface after pelvic fixed tapping. The effects on erector spinae and hamstring muscles was statistically significantly lower (p<.05), it was confirmed that there were no statistically significant differences between the multifidus and gluteus maximus muscle (p>.05). Conclusion : Through this study, it was found that the excessive flexion of the waist was significantly reduced from erector spinalis and hamstring muscle after abdominal drawing-in bridging exercises by verbal cue on the unstable supporting surface after pelvic rearward sloping tapping compared to the general bridging exercises.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2852-2854
• /
• 2005

In this paper, we propose a method to a synchronization of chaotic mobile robots that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a VDP (Van der Pol) equation with an unstable limit cycle. The proposed methods are assumed that if one of two chaotic mobile robot receives the synchronization command, the other robot also follows the same trajectory during the chaotic robot search on the arbitrary surface.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2005.05a
• /
• pp.215-221
• /
• 2005

In this paper, we propose a method to a synchronization of chaotic UAVs that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. The proposed methods are assumed that if one of two chaotic UAVs receives the synchronization command, the other UAV also follows the same trajectory during chaotic UAVs search on the arbitrary surface.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.3
• /
• pp.141-146
• /
• 2008

The purpose of this study is to develop the algorithm which can control muscle power assist robot especially for elderly. Recently, wearable robots for power assistance are developed by many researchers, and its application fields are also variable such as for medical or military equipment. However, there are many technical barriers to develop the wearable robot. This study suggest a control method improving performance of a wearable robot system by using a EMG signal of major muscles and a force sensor signal as command signal of system. The result of the robot Prototype efficiency experiment, the case of Maximum Isometric motion it suggest 100% power of muscle, the man need only 66% of MVIC(Maximum Voluntary Isometric Contraction) to lift 5kg dumbbell without robot assist. However the man needs only 52% of MVIC to lift 5kg dumbbell with robot assist. Therefore 20% muscle power increased with robot assist. Also, we designed light weight robot mechanism that extract the command signal verified and drive the wanted motions.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.33-34
• /
• 2007

• Analytical Science and Technology
• /
• v.30 no.6
• /
• pp.319-328
• /
• 2017

The identification of explosive residues on specimens obtained from an explosion event is a crucial factor for assessing the cause of the explosion. In order to detect the components of explosives, the explosive residues deposited on surfaces are commonly extracted using swabbing materials pre-wetted with an organic solvent. The residues are then analyzed with analytical instruments such as LC/MS and CE/MS. Most conventionally used swabbing media such as cotton swabs or cotton tip swabs seem unsuitable for extracting explosive residues from the surface of a large area of clothes because the swabbing materials tend to be damaged easily, and because only a relatively small amount of explosives is collected. To overcome these problems, we have introduced a novel wiper ($215{\times}210mm$, single layer, Yuhan-Kimberly, Republic of Korea) as a swabbing material to recover representative organic explosives, namely, TNT, RDX, tetryl, HMX, PETN, and NG, from a large area of clothes. Different sides of the wiper, which was folded in half five times, was used to swab the surface of a clothing. We compared this novel wiper with a cotton swab and a cotton tip swab in terms of the recovery efficiency for the aforementioned organic explosives by pre-wetting with methanol, acetone, and acetonitrile, respectively. We identified that this novel wiper collected a significantly higher amount of organic explosive residues than a cotton swab or a cotton tip swab when using methanol as an extracting solvent.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.638-641
• /
• 1992

In this paper, a hybrid position/force control scheme is proposed. The control scheme modifies the position command for force control against constraint surface of environment and is very simply designed and implemented. The merits of the control scheme are that it can cope with change of constraint conditions and small position inaccuracy of the environment. A constraint surface position observer is also proposed to reduce disturbances on controlled force.