• 제목/요약/키워드: External and internal stability

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Experimental Study on the Control for a Randomly Disturbing Dynamic System (불규칙한 교란을 받는 동적 시스템의 제어에 관한 실험적 연구)

  • Lee, Jong-Bok;Cho, Yun-Hyun;Yang, In-Beom;Park, Sung-Man;Heo, Hoon
    • Proceedings of the KSME Conference
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1120-1125
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    • 2007
  • Experimental study on the control of randomly disturbing system is conducted. External and internal disturbances are imposed to the system in combined manner. A vertical propeller system exposed horizontal weak turbulent air flow is chosen as an experimental model. The aim of the control system is to maintain the angular position of vertical propeller in parallel to air flow. Trajectory Tracking Stochastic Controller (TTSC) is designed to ensure system's stability while following system command. The Trajectory Tracking Stochastic Controller is composed of two controller, one is stochastic controller to suppress internal random noise and the other one is trajectory-tracking controller to follow the command having random noise. The proposed hybrid controller, TTSC, shows remarkable performance in pitch control of vertical propeller system in wind-tunnel test

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Ego-Identity of Women Seeking Double Eyelid Operation (쌍꺼풀성형술을 원하는 여성의 자아주체성)

  • Choi, Young;Lee, Mi-Suk;Lee, Moo-Suk
    • Korean Journal of Psychosomatic Medicine
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    • 제2권1호
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    • pp.80-87
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    • 1994
  • Objective : Cosmetic surgery, as a psychosocial intervention, is unique in that its foundation rests solely on the individual motivations, internal or external, of the patient We investigated the ego-identity in women who seek double eyelid operation, to understand one aspect of internal motivation for cosmetic surgery. Methods : Subjects of this study were 47 young women, visited to plastic surgery clinics in Kwangju from June 1993 to October 1993, and 58 women who did not want double eyelid operation were chosen as controls. Each subject's ego-identity was scored using Dignan's ego-identity scale. Results : The total and stability subscale's scores of ego-identity of double eyelid operation group were significantly lower than those of control group. Conclusion : More psychosocial research on the ego-identify of patients seeking double eyelid operation is required to understand the psychological motives for requesting surgery.

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Effects of Core Stability Exercise on Strength, Activation of Trunk Muscles and Pulmonary Function in a Guillain-Barre Syndrome Patient: Case Report (코어 안정화 운동이 길랭바래증후군 환자의 몸통 근력, 근활성도 및 폐기능에 미치는 영향: 증례보고)

  • Eum, Young-Bae;Yoo, Kyung-Tae;Lee, Yun-Hwan;Lee, Ho-Seong
    • Journal of the Korean Society of Physical Medicine
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    • 제16권1호
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    • pp.111-121
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    • 2021
  • PURPOSE: This study examined the effects of core stability exercise on the strength, activation of the trunk muscle, and pulmonary function in a Guillain-Barre syndrome (GBS) patient. METHODS: A 38-year-old male with GBS was enrolled in the study. A core stability exercise program was implemented for four weeks with a duration of 30 min/day and a frequency of three days/week. The program consisted of abdominal crunch, Swiss ball crunch, bicycle crunch, medicine ball sit-up with a toss, medicine ball rotational chest pass, raised upper body and lower body, and dead bug. Measurements of the strength of the trunk muscle (trunk flexion and hip flexion), activation of trunk muscles (rectus femoris; RA, external oblique abdominal; EOA, internal oblique abdominal; IOA, erector spinae; ES), and pulmonary function (forced expiratory capacity; FVC, forced expiratory volume at one second; FEV1) were taken before and after four weeks of core stability exercise. RESULTS: The strength of trunk muscles increased in the trunk and hip flexion after four weeks of core stability exercise, respectively, compared to the baseline levels. Activation of the trunk muscles increased in RA, EOA, and IOA after four weeks of core stability exercise compared to baseline levels, but decreased in ES after four weeks of core stability exercise compared to the baseline levels. The pulmonary function increased in FVC and FEV1 after four weeks of core stability exercise compared to the baseline levels. CONCLUSION: These results suggest that core stability exercise improves strength, Activation of the trunk muscle, And pulmonary function in patients with GBS.

The Comparison of the Characteristics of Partially Purified Internal Invertase by Mating Type in the Heterobasidiomycetous Yeast (이담자 효모균의 성접합형에 따른 세포내 Invertase의 성질 비교)

  • 정영기;김병우
    • Microbiology and Biotechnology Letters
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    • 제20권6호
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    • pp.625-629
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    • 1992
  • This work was carried out to study physiological characteristics of Rhodosporidium toru[oides cells having two different mating types. The mating type A produces internal. cell wall-bound, and external invertases while type a produces only two invertases except external invertase. Comparing their characteristics after partial purification of internal invertases from both mating type cells, invertase from type a has decreased 15% of invertase activity only by $Mn^{2+}$ I while invertase from type A has been increased 11% of invertase activity by $Zn^{2+}$ and decreased 15% of invertase activity by $Mn^{2+}$ On the effect of enzyme inhibitor, invertase of type a was inhibited from 12% to 57% by 2-mercaptoethanol, sodium dodecyl sulfate, phenol. but invertase of type A was slightly inhibited only by phenol. The thermal stability of both invertases has showed steep inactivation at above $80^{\circ}C$ and their optimal temperatures were similar at $60^{\circ}C$ . Invertase from type A showed stability only on condition of acid from pH 3 to 6 and its opimal pH was 5.0, while invertase from type a showed stability at the wide range of pH 3-10 and its optimal pH was 4.0. And the $K_m$ values of invertases from type A and type a were $2.5{\times}10^3$M and$3.4{\times}10^3$M, respectively.

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Comparison of Abdominal Muscle Activity Between the Abdominal Bracing Technique Emphasizing Inhalation and the General Bracing Technique and Hollowing Technique

  • Yun, Kyoungup;Jung, Ki-Bum;Lee, Yongwoo
    • Physical Therapy Rehabilitation Science
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    • 제11권2호
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    • pp.245-252
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    • 2022
  • Objective: This study aimed to investigate the abdominal muscle activity difference while performing the abdominal bracing technique focusing on inspiration (abdominal bracing group), the general abdominal bracing technique (general bracing group), and the abdominal hollowing technique (abdominal hallowing group) Design: A cross-sectional study design. Methods: Thirty-three healthy participants were recruited for this study. The participants were allocated to 3 different groups; Abdominal bracing group, general bracing group, and abdominal hallowing group. The surface electromyography was placed over the rectus abdominis, external oblique, and internal oblique muscles to collect the activation of abdominal muscles during the trial. Results: The muscle activity of the abdominal bracing group and general bracing groups was significantly higher in all abdominal muscles than in the abdominal hollowing group (p<0.05) Both rectus abdominis and external oblique muscles showed higher muscle activations in the abdominal bracing group over the general bracing group (p<0.05). However, the ratio of bilateral external obliques and rectus abdominis to bilateral internal obliques was highest when the hollowing technique was applied (p<0.05). Conclusions: The results of study showed the abdominal bracing technique that emphasized inhalation rather than the abdominal hollowing technique or general abdominal bracing technique increased the activity of the abdominal muscles. Therefore, this study is considered to be a data for effective training if the abdominal bracing technique that emphasizes inhalation is applied as a method to increase the activation of the abdominal muscles.

Study on Combination of External Gosamgamibang and Internal Chenggihaedok-san for the Treatment of Atopic Dermatitis (아토피피부염에 대한 고삼가미방(苦參加味方)과 청기해독산(淸肌解毒散)의 겸용 투여 효과)

  • Ko, Hong-Yun;Kim, Dong-Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제23권6호
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    • pp.1282-1291
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    • 2009
  • A combined prescription of GGB and CHS (G&C prescription group) was used to investigate its effects on immune related factors and histological changes in atopic dermatitis(AD) induced mice. Significant decrease of atopic dermatitis clinical index in G&C prescription group. In DLN, G&C prescription group significantly modulated the immune cells. G&C prescription group also showed significant effect on the immune cells of the dorsal skin as well as DLN. The group indicated significant decrease of the biosynthesis of IL-4, IL-5, IL-13, GM-CSF, cytokines in serum. On the other hand, the biosynthesis of TNF-$\alpha$ was decreased. G&C prescription group significantly decreased the immunoglobulin IgE levels in serum. The results suggest that G&C prescription significantly improves atopic dermatitis through regulation of immune cells and cytokines. Comparative studies with Protopic ointment also showed that G&C prescription showed significant effect in AD patients, and active application of the prescription in clinicals is anticipated. However, the reason for the results that oppose to those of previous studies should be investigated. Also, therapeutic effects of both internal and external applications should be studied individually as well as for any synergistic effects. Safety, toxicity, as well as stability studies should follow to develop G&C prescription into long-term external clinical product.

Stability of Railway Bridge Abutment with Earth Pressure and Internal Friction Angle of Backfill (내부마찰각과 토압 산정방법에 따른 철도교대의 안정성 비교 연구)

  • Choi, Chan Yong;Kim, Hun Ki;Yang, Sang Beom;Kim, Byung Il
    • Journal of the Korean Society for Railway
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    • 제19권6호
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    • pp.765-776
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    • 2016
  • In this study, a standard section of a railway bridge abutment wall was designed to satisfy the external stability condition in accordance with the design criteria; this design was used to compare and analyze the active earth pressure and to calculate various types of earth pressure acting on the virtual back (wall, plane) according to the frictional angle of the backfill materials. Also, the external stability, member force and construction cost were analyzed according to the frictional angle of the backfill materials using various theories of earth pressure such as Rankine, Coulomb, Trial Wedge, and Improved Trial Wedge. As for the results, it was found that lateral earth pressure at the virtual back plane was higher than at the virtual back wall, and that these values decreased with the increase of the frictional angle of the backfill materials. The increasing of the frictional angle of the backfill materials decreased the active earth pressure (according to Rankine, Coulomb, Trial Wedge, and Improved Trial Wedge results), and the member force as well as the construction cost were reduced.

Effect of Sprinter Pattern Bridging Exercise using Theraband on Activation of Lower Extremity and Abdominal Muscle

  • Kim, Gwanho;Yi, Donghyun;Yim, Jongeun
    • Physical Therapy Rehabilitation Science
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    • 제10권3호
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    • pp.244-250
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    • 2021
  • Objective: The purpose of this study was to investigate the effect of sprinter pattern bridging exercise using theraband on activation of lower extremity and abdominal muscle and to find out postures that can effectively improve abdominal and lower extremity muscle strength and increase abdominal stability. Methods: This study was designed as a cross-sectional study. The following research was done with applicants attending S university in Seoul to compare the difference in muscle activity between one-leg-Support bridging exercise and sprinter-pattern bridging exercise using theraband. For 48 study participants, we first measured their MVC. Then, we applied one-leg-support bridging exercise and sprinter-pattern bridging exercise at random order. These data were expressed as the percentage of maximal voluntary contraction (%MVC).Electromyography analysis was performed by measuring the external obliques, internal obliques, biceps femoris, and gluteus maximus. Results: There was a statistically significant increment of muscle activity in external and internal oblique muscle(p<0.001)by sprinter-pattern bridging exercise using theraband. On the lower body, statistically significant increment of muscle activity in biceps femoris and gluteus maximus was found(p<0.05). On the other hand, on erector spinae, there was statistically significant decrease in muscle activity(p<0.05). Conclusions: Efficient treatment is expected when sprinter-pattern bridging exercise using theraband is applied clinically.For patients with chronic knee and ankle pain who have difficulty bearing weight, including low back pain and internal rotation of the femur, starting with a low weight bearing, we think it will be helpful in planning systematic training aimed at progressively strengthening the lower extremities.

Case Study of Environmental Segmental Retaining Wall(SRW) Using Greenstone Block (환경친화적 블록식 보강토옹벽의 설계 및 시공사례연구)

  • Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • 제7권6호
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    • pp.19-28
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    • 2004
  • Segmental Retaining Wall(SRW) has been variously applying in Civil and Architecture construction. Recently, the application of environmental element in all type's structures came to essential requirement, and the construction cases of retaining wall using reinforced soil and block are more increased than the past. But, this trend more widely was spread environmental element as landscape work for the backside of reinforced retaining wall as well as block itself. New environmental block, Greenstone Block, developed to apply of this tendency. The retaining wall system using Greenstone can be environmental constructing at both block itself and backside of retaining wall. The material tests, the axial compressive strength test of block and bending test of fiber-pipe, exercised to design and construction of vertical SRW, which were satisfied NCMA standard. Through this procedure, Rewall (ver 1.0) was developed, which can be automation design of SRW including internal stability, external stability and local stability. And these can be considered setback of retaining wall, as well the examples of vertical retaining wall using block presented to satisfying the follows; strength of reinforced geotextile, height of retaining wall, surcharge, types of backfill and groundwater level etc. Many problems investigated on after or before of construction were due to local failure, insufficiency of bearing capacity and groundwater level. Especially, the local failure was many occurred to during compaction or after construction, and the cases of SRW construction is similar to the results of model test on vertical SRW.

Relationship between Strengths of the Lower Extremity's Joints and Their Local Dynamic Stability during Walking in Elderly Women (보행 시 여성 노인의 하지 관절 근력과 국부 동적 안정성과의 관계)

  • Ryu, Jiseon
    • Korean Journal of Applied Biomechanics
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    • 제31권1호
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    • pp.30-36
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    • 2021
  • Objective: The objective of the present study was to analyze the relationship between strength of the lower extremity's joints and their local dynamic stability (LDS) of gait in elderly women. Method: Forty-five elderly women participated in this study. Average age, height, mass, and preference walking speed were 73.5±3.7 years, 153.8±4.8 cm, 56.7±6.4 kg, and 1.2±0.1 m/s, respectively. They were tested torque peak of the knee and ankle joints with a Human Norm and while they were walking on a treadmill at their preference speed for a long while, kinematic data were obtained using six 3-D motion capture cameras. LDS of the lower extremity's joints were calculated in maximum Lyapunov Exponent (LyE). Correlation coefficients between torque of the joints and LyE were obtained using Spearman rank. Level of significance was set at p<.05. Results: Knee flexion torque and its LDS was negatively associated with adduction-abduction and flexion-extension movement (p<.05). In addition, ratio of the knee flexion torque to extension and LDS was negatively related to internal-external rotation. Conclusion: In conclusion, knee flexion strength should preferentially be strengthened to increase LDS of the lower extremity's joints for preventing from small perturbations during walking in elderly women.