• Title/Summary/Keyword: Standing

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THE DELTA STANDING WAVE SOLUTION FOR THE LINEAR SCALAR CONSERVATION LAW WITH DISCONTINUOUS COEFFICIENTS USING A SELF-SIMILAR VISCOUS REGULARIZATION

  • LI, XIUMEI;SHEN, CHUN
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.6
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    • pp.1945-1962
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    • 2015
  • This paper is mainly concerned with the formation of delta standing wave for the scalar conservation law with a linear flux function involving discontinuous coefficients by using the self-similar viscosity vanishing method. More precisely, we use the self-similar viscosity to smooth out the discontinuous coefficient such that the existence of approximate viscous solutions to the delta standing wave for the Riemann problem is established and then the convergence to the delta standing wave solution is also obtained when the viscosity parameter tends to zero. In addition, the Riemann problem is also solved with the standard method and the instability of Riemann solutions with respect to the specific small perturbation of initial data is pointed out in some particular situations.

A Study on the Diagnosis and Improvement of Present Superintendent Election and Education Standing Committee System (현행 교육감 선거 및 교육상임위원회제도 진단 및 개선연구)

  • Joo, Chul-An
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.1
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    • pp.22-33
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    • 2014
  • This study is to diagnose the present superintendent election and education standing committee system for improvement based upon Constitutional values of local education system. The findings are the followings. To improve the election system of superintendent it is recommended to maintain present election system rather than change it drastically since the present system ensure relatively more autonomy, expertise, and political neutrality of local education system. However, the qualification such as years of educational experiences of superintendent candidates need to be restored. Regarding education standing committee it suggest that all or at least 2/3 members need to be educational representatives rather than general representatives. For superintendent as well as education standing committee election, it needs to elaborate the vote ballet such as change of candidates name order by voting place to reduce its effects to election results. It also needs to strengthen public management of election such as expenses and TV forums among candidates.

The Standing Crop and Edaphic Factor of Grasslands in Chuiwon near the D.M.Z. (철원지구 비무장지대 초지의 지력에 Standing Crop의 변동에 관한 연구)

  • 이정혜;장남기
    • Asian Journal of Turfgrass Science
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    • v.8 no.1
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    • pp.37-46
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    • 1994
  • We study on the standing crop and edaphic factor of grasslands in Chulwon near the D.M.Z. The widespread and most abundant grasses are Arundinella hirta and Miscanthus sinensis in the upland fields of D.M.Z. The vascular flora of grasslands in Umi-dong and Sukda-dong near the D.M.Z. and composed of total 25 species, the most important of which ace Arundinella hirta and Miscanthus sinensis These two species contribute greatly to the standing crop of live naterial was in excess of $107.6g /m^2$. Correlation between standing ccop and water content, organic matter, total nitrogen, or avail-able phosphorus of grassland soils in area studied is high significant. It is argued that these edaphic factors affect the growth of grasses in Umi-dong and Sukda-dong grasslands.

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The Effect of Symmetrical Standing Posture in Cerebral Palsied Children after Visual and Auditory Feedback Training (시각 및 청각 되먹임을 통한 뇌성마비 아동의 좌우 대칭척 서기 자세 훈련 효과)

  • Kim, You-Hyun;Park, Koan-Su;Cheon, Mee-Hye;Kim, Jong-Man
    • Physical Therapy Korea
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    • v.1 no.1
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    • pp.17-24
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    • 1994
  • Biofeedback devices have been used successfully to improve head control and symmetrical walking in cerebral palsied children. Biofeedback of postural sway was investigated as a therapeutic technique to reduce postural abnormality in 24 selected children with cerebral palsy. Subjects were evaluated their weight distribution of both sides during their standing before and after the visual and auditory feedback training. The effectiveness of biofeedback was compared to conventional physical therapy practices in reestabilishing symmetrical standing in cerebral palsied children. Our study found biofeedback was effective in training symmetrical standing posture.

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Comparison and Selection of Standing / Sedentary Work Posture for A Light Assembly Work (경조립작업을 위한 입/좌식 작업자세의 비교 및 선정)

  • 김해진;임현교
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.108-114
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    • 2000
  • The work posture impose additional stress upon human workers so that it should be carefully considered in designing works. However, we have a lot of manufacturing plants which convert their standing workplace to sedentary one. To confirm the validity of that trend, the authors conducted an experimental study, and compared the results. The results of the EMG and the self-cognitive symptoms, in general, showed a correspondent trend that the sedentary work posture was rated more comfortable. At the beginning of the work, complaint of the lowerback was higher whereas that of the lower leg and the feet went higher as the time elapsed. If the weight of workpiece were heavier than 500g, increasing rate of bodily discomfort in the sedentary posture were greater than that of the standing posture. In the meanwhile, the standing posture was consistently superior to the sedentary posture in its performance. Thus, in conclusion, for a light assembly work, sedentary work posture would be recommendable because bodily discomfort would be larger irrespective of the small increase of performance increase.

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The "Standing Alone" Process of Divorced Single Fathers (한부모 이혼 남성의 홀로서기과정)

  • Rho, Jung-Ja;Kang, Ki-Jung
    • Journal of Family Resource Management and Policy Review
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    • v.16 no.2
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    • pp.145-163
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    • 2012
  • The purpose of this study is to understand the process of "standing alone" in divorced single fathers on the basis of qualitative data collected through in-depth interviews with 10 divorced single fathers. Data were analyzed on the basis of grounded theory analysis in open coding, and 154 concepts, 39 sub-categories, and 14 categories were derived. According to the results of this study, the process phenomenon of divorced single fathers' standing alone was "the restraint and chaos of pain". This study could identify the consecutive process of four identified stages: marriage life's rupture, pain and chaos, deliberation and decision, and role adaption. In selective coding, the core category was "to pass through the restraint of pain and embrace children and stand alone". There were three types of standing alone: maintaining barely, enduring hopefully, and living initiatively. This study showed the necessity of social support and the basic data by type analysis through the process of standing alone. This study provided substantive knowledge generated through the voices of the persons concerned.

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Assessment of Muscle Fatigue Associated with Prolonged Standing in the Workplace

  • Halim, Isa;Omar, Abdul Rahman;Saman, Alias Mohd;Othman, Ibrahim
    • Safety and Health at Work
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    • v.3 no.1
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    • pp.31-42
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    • 2012
  • Objectives: The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. Methods: The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. Results: Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant ($r_s$ = 0.552, p < 0.05) between the results of questionnaire surveys and sEMG measurement. Conclusion: Based on this study, the authors concluded that prolonged standing was contributed to psychological fatigue and to muscle fatigue among the production workers.

Transient Effects of Calf Muscle Fatigue and Visual Control on Postural Balance During Single Leg Standing

  • Han, Jin-Tae
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.3
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    • pp.67-71
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    • 2017
  • PURPOSE: Muscle fatigue is a cause to change proprioception. The purpose of this study was to investigate the effects of calf muscle fatigue and visual control on postural balance during single-legged standing in healthy adults. METHODS: Nineteen healthy adults (male) were participated in this study (mean age: 24.36 years; mean height: 171.32 cm; mean weight: 64.58 kg). The postural balance (sway length, sway area, sway velocity of COG displacement) was measured by Balance Trainer System (BT4) in before and after calf muscle fatigue feeling in single legged stance. In this study, repetitive single-legged heel rise test was used to induce fatigue of the calf muscle. Paired t- test was used to compare the postural balance between before and after calf muscle fatigue. Data of subjects were analyzed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA). Level of significance was set to .05. RESULTS: The sway length, sway area, sway velocity of COG (center of gravity) displacement after calf muscle fatigue feeling was significantly increased compared to before calf muscle fatigue feeling during single leg standing both eye open and close conditions (p<.05). CONCLUSION: This study suggested that calf muscle fatigue feeling has affected on postural balance when standing one leg both eye open and close conditions and postural control was disturbed by muscle fatigue and visual feedback in single leg standing.

Sex Difference in the Range of Pelvic Tilt in Sitting and Standing Among Korean Young Adults

  • Yoon, Jangwhon
    • Physical Therapy Korea
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    • v.27 no.2
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    • pp.149-154
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    • 2020
  • Background: The range of pelvic tilt is one of modifiable risk factors in preventing the lower back pain. Objects: The purpose of this study were to compare the range of pelvic tilt motion by testing position and sex. Methods: One hundred five young adults (61 females and 44 males) agreed to participate in measuring the anterior and posterior pelvic tilt with the PALM (Palpation Meter) in sitting and standing. The range of pelvic tilt motion was defined as the difference between the pelvic anterior and posterior tilt angles. Results: In general, the anterior pelvic tilt was greater (p < 0.01) in standing than in sitting and the posterior pelvic tilt was lesser (p < 0.01) in sitting than in standing. The anterior pelvic tilt in sitting and standing was greater (p < 0.01) in the females than in the males. However, the effect of sex on the posterior pelvic tilt was only significant in sitting (p < 0.01), but not in standing (p = 0.78). The range of pelvic tilt was greater (p = 0.03) in sitting but not significantly (p = 0.07) affected by the sex. Conclusion: The pelvic tilt motion in these young adults showed large variability and further studies are needed to understand better its relationship to the prevalence of the lower back disorders.

On Changes of Postural Sway with Ageing (연령증가(年齡增加)에 따른 신체동요(身體動搖)의 변화(變化)에 대하여)

  • Sin, Seung-Heon
    • Journal of the Ergonomics Society of Korea
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    • v.5 no.1
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    • pp.3-9
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    • 1986
  • This research is aimed at examining age-related changes of postural sway when people stand upright, examining external effects which can be exerted upon the postural sway (experiment 1), and also analyzing specific changing characters of posture-control by sudden impacts (experiment 2). The total number of subjects was 115, who are in twenties through seventies and 75 of them were participated in experiment 2. In experimen 1, the subjects were examined for 25 seconds respectively while standing upright with both feet and with eyes opened, standing upright with both feet and with eyes closed, and standing upright with a single foot and with eyes opened. In experiment 2, only while standing upright with both feet and with eyes opened they were examined for 5 seconds. Main findings were as follows: 1. In the single-foot standing position, the growing older exerted more important effects upon the fluctuation length and area of the center of gravity than in the both-foot standing position. 2. The standard deviation was increasing with age in the fluctuation length and the fluctuation area of the center of gravity. 3. There were no significant differences in daily variation, temperature change, and muscle burdening. 4. The recuperation from the postural sway by external impacts was so slow with age. 5. There were little differences in decrease frequencies among the subjects but younger persons.

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