• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.932-935
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• 1996

This paper proposes position estimation and path-tracking of a wheeled-mobile robot(WMR). Odometry and two distance measuring sensors are used to measure distance between guide wall and body and to locate its own position. And extended Kalman filter is introduced to fusion sensors and reduce noise. State feedback controller using the estimated position and path-tracking miles guidance control system. The computer simulation shows that proposed algorithm is well coincide with theoretical approach.

• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1140-1147
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• 2003

We have examined the effect on neck-muscle activation of altering whole body posture. A Rhesus monkey (Macaca mulatta) was trained to produce sinusoidal (0.25 Hz) head tracking movements in the sagittal plane when seated with trunk and head vertical or while standing in the quadrupedal position. Video-fluoroscopic images of cervical vertebral motion, and electromyographic (EMG) responses were recorded simultaneously. Results demonstrated that vertebral motion varied with body posture, occurring synchronously between all joints in the upright position and primarily at skull-$C_1$ when in the quadrupedal position. Muscle EMG activation was significantly greater (P<0.001) in the quadrupedal position than when upright for all muscles except semispinalis cervicis. Peak activation of all the muscles occurred prior to peak head extension in the quadrupedal position, suggesting synchronous activity between muscles. Data suggest that, when upright, muscles were activated in functional groupings defined by their anatomical arrangement. In the quadrupedal position, gravity acting on the horizontally oriented head produced greater activation and a collective response of the muscles.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.44-48
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• 2008

Purpose: In FDG-PET/CT of breast cancer, a sensitivity was 80~96% and a specificity was 75~95% commonly. It was valuable to identify a cancer in early stage been difficult in Mammography. Most of the PET/CT scans have been examined on supine position, so, the image of breast has been acquired by reconstructed whole body scan image. However, using prone position with a compensator, a shape of breast was reassembly shown to be real by gravity. Therefore, the purpose of this study was to evaluate diagnostic value of prone position in FDG PET-CT of breast cancer. Materials and Methods: 30 female patients with doubtful or positive breast cancer were examined. The PET-CT whole body scan was acquired at 60 minutes after $^{18}F$-FDG injection on Supine position. Then, regional breast spot scan was progressed on prone position using a compensator. Each image was evaluated by physicians blinded to patient's data, and statistical analysis did through SUVs measured in PET-CT images. Results: In 27 of 30 patients, prone position was shown accurate discrimination and diagnostic value, but in another 3 patients had a lesion 1cm below, PET-CT couldn't detect it, unlike MRI. Consequently, prone position distinguished a lesion better than Supine position, because of low degree of metamorphosis by gravity. The SUVs analysis of each position was significant (p value=0.004). Conclusion: In PET-CT of breast cancer, prone position could detect micrometastasis as well as primary lesion, better than supine position. Therefore, this study proposes that any technical change considered morphological feature like prone position can offer adequate and useful diagnostic information, together with complementary quantitative analysis.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.2
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• pp.30-38
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• 2003

This paper proposed PID controller for torch slider and PD controller for motor right wheel. to control the motion of two-wheeled welding mobile robot with seam tracking sensor touched on welding line. The motion control is realized in the view of keeping constant welding velocity and precise seam tracking even though the target welding line is on straight line or curved line. The position and direction of the body of the mottle robot are controlled by using signal errors between seam tracking sensor and body positioning sensor attached on the end of torch slider and body side of the mobile robot, respectively. In turning motion, the body and the torch slider are controlled by using the kinematic model related with two motions of body turning and torch sliding. The straight locomotion is controlled according to eleven control patterns obtained from displacements between two sensors of the seam tracking sensor and the body positioning sensor. The effectiveness is proven through the experimental results fur lattice type welding line. Through the experimental results, we can see that the position value of the electrode end point and the welding velocity are controlled almost constantly both in straight and turning locomotion.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.257-263
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• 2000

One of the basic assumptions in the static gait design for a walking robot is that the weight of leg should be negligible compared to that of body, so that the total gravity center is not affected by swing of a leg. Based on the ideal assumption of zero leg-weight, conventional static gait has been simply designed for the gravity center of body to be inside the support polygon, consisting of each support leg's tip position. In case that the weight of leg is relatively heavy, however, while the gravity center of body is kept inside the support polygon, the total gravity center of walking robot can be out of the polygon due to weight of a swinging leg, which causes instability in walking. Thus, it is necessary in the static gait design of a real robot a compensation scheme for the fluctuation in the gravity center. In this paper, a body impedance control is proposed to obtain the total gravity center based on foot forces measured from load cells of a real walking robot and to adjust its position to track the pre-designed trajectory of the corresponding ideal robot's body center. Therefore, the walking stability is secured even in case that the weight of leg has serious influence on the total gravity center of robot.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.3
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• pp.191-199
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• 2011

In this paper, we adopt a position specific scoring matrix as an abstraction of amino acid type to derive two new statistical potentials for protein structure prediction, and investigated its effect on the quality of the potentials compared to that derived using residue specific amino acid identity. For stringent test of the potential quality, we carried out folding simulations of 91 residue A chain of protein 2gpi, and found unexpectedly that the abstract amino acid type improved the quality of the one-body type statistical potential, but not for the two-body type statistical potential which describes long range interactions. This observation could be effectively used when one develops more accurate potentials for structure prediction, which are usually involved in merging various one-body and many-body potentials.

• IE interfaces
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• v.10 no.3
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• pp.197-208
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• 1997

In workplace design, an ergonomic solution should ensure low postural stress in the operator during his/her work. Stress caused by awkward working postures of the trunk, shoulders and legs can result in fatigue, discomfort, musculo-skeletal disorders and nerve entrapment syndromes. Since discomfort and musculo-skeletal disorders are both related to exposure to biomechanical load on the musculo-skeletal system, minimization of discomfort will contribute to reduction of the risk for musculo-skeletal disorders as well. Therefore, in this study, perceived discomfort on the human body joints was measured in the standing postures using the magnitude estimation in order to have a standardized numerical scale for joint discomfort. Nine healthy graduate students participated voluntarily in the laboratory study. The results revealed that perceived discomfort of all the joints increased as the joints deviated from neutral position. Especially, it showed drastic increment on perceived discomfort when deviation from neutral position in each human body joint increased from 75% to 100%. in terms of relative range of motion(R0M). On the basis of these experimental results, a preliminary ranking for assessment of stressfulness of non-neutral postures around the human body joints was suggested.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.375-380
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• 2006

Purpose : This study investigated how gross motor and fine motor development are influenced by sleep position. Methods : From December, 2003 to September, 2005, for a year and 9 months, 800 children aged from 3 months to 16 months, who visited the Presbyterian Medical Center, Chonju, Korea were surveyed for motor development scale, sleep position and body weight. Results : The sleep position came in order : 79.3 percent of supine position, 10.0 percent prone position and 10.7 percent side position. Gross motor scale and fine motor scale were not connected with sex. The prone position indicated remarkable increase on gross motor scale from 5-6 months, but stayed the same after 7 months. Fine motor scale was not related to age and sleep position. Gross motor scale and fine motor scale were higher on group weighing more than under average weight group. Conclusion : This study showed that prone position did not influence gross motor scale after 7 months, affecting children of 5-6 months only. Hence, It is not recommended to use the prone position for a baby's fast gross motor development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3513-3520
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• 2012

This study aimed to investigate the difference of the body orientation ability in sitting position to adapt to dynamically changing angle of the base of support in stroke patients and Healthy adults. The angle between vertical and head and trunk in 12 stroke patients (6 male and 6 female) and 12 healthy adults (6 male and 6 female) were measured by video motion analysis system. The head and trunk angle between stroke patients and healthy adults in sitting position were significantly different when increase the angle of dominant side(p<.05). The head and trunk angle between stroke patients and healthy adults in sitting position were significantly different when increase the angle of non-dominant side(p<.05). The head and trunk angle between stroke patients and healthy adults in sitting position were significantly different when decrease the angle of non-dominant side(p<.05). The head angle between stroke patients and healthy adults in sitting position was significantly different(p<.05), but the trunk angle was not significantly different when decrease the angle of dominant side(p>.05), Stroke patients compared to healthy adults had more deficits in their body orientation ability in sitting position to adapt to dynamically changing angle of the base of support. This finding may help to understand postural control deficits more clearly in stroke patients in sitting position.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.193-200
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• 2013

PURPOSE: The purpose of this study was to find out variations in body posture by using the baby carrier at the front side and back side. METHODS: Thirty two healthy and young female who will bring up infants and had no musculoskeletal disorders of neck, lumbar and low limb were recruited for this study. They were each marked about ears of tragus, cervical 7th, acromion anterior end, anterior superior iliac spine, posterior superior iliac spine, greater trochanter and lateral malleolus as landmarks to measure variations of body posture when they carry infants at the front side and back side. Landmarks were regarded as the creteria in order to measure NeckFlexion angle(NF), Foreward shoulder angle(FSA), Pelvic tilt(PT), Sway angle(SA), Head displacement(HD) and Scapular displacement(SD). Variations in body posture were measured from the neutral position to the front and back side by using Image J. RESULTS: There were significance level (p<.05) in NF, PT, SA, HD and SD except for FSA in two different side. CONCLUSION: The results of this study indicate that each of the using ways of baby carrier for baby care was influenced postural responses of young women. therefore, it could be considered to apply to women who have abnormal body posture in order to minimize musculoskeletal disorders.