• Title/Summary/Keyword: Phase Balance

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Thermodynamic Energy Balance Analysis of Underground Lined Rock Caverns (LRC) for Compressed Air Energy Storage (CAES) (복공식 지하 압축공기에너지 저장공동의 열역학적 에너지수지 분석)

  • Kim, Hyung-Mok;Park, Do-Hyun;Ryu, Dong-Woo;Choi, Byung-Hee;Song, Won-Kyong
    • Tunnel and Underground Space
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    • v.21 no.4
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    • pp.297-306
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    • 2011
  • In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

The effect of independent treadmill training on gait, balance and trunk control in a patient with chronic stroke (트레드밀 훈련이 뇌졸중 환자의 보행, 균형 및 체간조절에 미치는 영향)

  • Yoon, Seoung-Ic;Chun, Seung-Chul;Lee, Ju-Sang;Geoung, Shin-Ho;Lee, Duck-Sung;Oh, Duck-Won;Shim, Jae-Hun;Lee, Gyu-Wan
    • Journal of Korean Physical Therapy Science
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    • v.13 no.2
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    • pp.37-45
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    • 2006
  • The purpose of this study was to determine the effect of treadmill training on gait, balance, and trunk control in a patient with hemiparesis. A female subject who had suffered a left hemiparesis 12 months previously was selected for this study. A single subject ABA design was used. Eight data-collection sessions were conducted during each of three phases (baseline-intervention-withdrawal). During baseline and withdrawal phases, the treatment based on Bobath approach was performed for the subject, and during the intervention phase, treadmill walking training was added. Assessment tools were made using the 10 m walk test, Rivermead Visual Gait Assessment(RVGA), Berg Balance Scale(BBS), and a seated Lateral Reach Test(LRT). During the intervention phase, the time measured in 10 m walk test and the scores of RVGA and BBS were significantly improved, and the number of steps in 10 m walk test and LRT showed a small improvement. During withdrawal phase, the time measured in 10 m walk test and the scores of RVGA and BBS were shown the carry-over effect. This findings indicate that treadmill training has significant effect to gait function and balance in a patient with chronic hemiparesis.

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The Relationship between the Plantar Center of Pressure Displacement and Dynamic Balance Measures in Hemiplegic Gait (편마비 보행 시 족저압력중심의 이동특성과 동적균형능력의 상관관계 연구)

  • Park, Ji-Won;Nam, Ki-Seok;Back, Mi-Youn
    • Physical Therapy Korea
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    • v.12 no.1
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    • pp.11-21
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    • 2005
  • The purpose of this study was to investigate how COP displacement of a hemiplegic foot in stance phase during gait is related to clinical balance measures and the recovery stage in hemiplegic stroke patients. Twenty-eight functionally ambulant hemiplegic patients who had suffered from strokes and thirty age-matched healthy subjects participated in this study. COP parameters were calculated. Clinical balance was measured using the Functional Reach Test (FRT) and Timed Up and Go Test (TUGT). The recovery stage, proprioception, and clonus of the ankles or lower extremities were also measured for physical impairment status. The COPx max-displacement in the medial-lateral side of the stroke patients was significantly longer than that of the normal group (p=.038). The COPy max-displacement in the anterior-posterior side of the stroke patients was significantly shorter than that of normal group (p<.001). Significant differences in the COPx and COPy displacement asymmetry index were found between the two groups (p<.01). The FRT was correlated with the COPx displacement (r=.552) and COPy displacement (r=.765). The TUGT was correlated with the COPy displacement (r=-.588) only. The recovery stage of the lower extremities was correlated with COPy displacement (r=.438). The results of the study indicate that the characteristic of COP displacement in hemiplegic feet in stance phase during gait is related to balance ability and recovery in stroke patients. COP parameters acquired by the mapping of foot pressure in stance phase during gait will provide additional useful clinical information. This information can be used by clinicians to assess objectively the pathologic gait with other diseases and to evaluate the therapeutic effects on gait in stroke patients.

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A Study on the Performance Analysis of Single-Phase Induction Motor Considering Asymmetrical Concept (비대칭성개념(非對稱性槪念)을 고려한 단상전원용유도전동기(單相電源用誘導電動機)의 특성해석(特性解析)에 관한 연구(硏究))

  • Lee, Il-Chun;Kim, Chul-Woo;Hwang, Young-Moon
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.5-9
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    • 1989
  • In this paper, while 2-or 3-phase induction motor is driven with balance and no noise driving at dynamic and steady state condition. Single-phase induction motor is driven with pulsating torque except specific driving point. So we analyze the reason of producing pulsating torque with the view of unsymmetring concept. These results are applied to the design of high efficincy, high quality single-phase induction motor.

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HIGH SPEED VARIABLE SQUARE WAVE AC SUBMERGED ARC WELDING -FREQUENCY/BALANCE STUDY .250″ PLAIN CARBON STEEL

  • Reynolds, Jon-O;Sean P. Moran
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.361-365
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    • 2002
  • Advancements in silicon phase control (SCR) technologies provide an arc welding power supply that has the capability to allow the alteration of the Alternating Current (AC) welding output. These technologies provide a square wave output involving sixteen frequency selections and multiple balance selections. While an AC out put is known to minimize magnetic disturbances associate with Direct Current (DC), the potentials of a non-sinusoidal waveform have not been explored. The focus of the paper is to determine the effects that the frequency and balance of an AC wave form output will have upon a high speed Submerge Arc (SAW) application. The test matrix of the project includes welding .250" steel plate. Joint type is square groove with a travel speed of 65 IPM. Each of the weld parameters was held constant, only the frequency and/or balance were altered between welds. Each frequency/balance combination involved three-gap spacing. Upon completion of the welds the bead profiles were measured and recorded. A relationships/trends were observed with various frequency and balance values. Optimum frequency and balance values were found for the .250" square groove application which permit consistent weld sizing, ease of slag removal, and minimal plate distortion.

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Review on Fukuda Stepping Test, Its Procedures and Criteria for the Evaluation of the Postural Balance Control (자세음양 균형검사로서 Fukuda Stepping Test에 대한 문헌적 고찰)

  • Bae, Jin Yong;Lee, Jaemin;Lee, Gyeong Ran;Lee, Young Jun;Yin, Chang Shik
    • Journal of TMJ Balancing Medicine
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    • v.4 no.1
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    • pp.5-7
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    • 2014
  • Objectives: Neurological examination on balance function is widely applied in clinical practice. Balance function may be clinically relevant to an assessment of yinyang balance in such therapies as temporomandibular joint balancing medicine. Fukuda stepping test is a relatively not-well-known method of balance function test. This study reviewed the procedures and criteria of Fukuda stepping test. Method: Recent articles on Fukuda stepping test were searched in public database (Pubmed, Proquest) and reviewed for its procedures and clinical implications. Results: Fukuda stepping test adopts 50 steps or 100 steps with subsequent assessment of the deviation or displacement of the subject. It may not be reliable during acute phase. Conclusion: Fukuda stepping test may be utilized and be further developed to assess balance function in the neurological management of functions.

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Phase transformer method and its application (위상변성방식과 그 응용)

  • 오상세
    • 전기의세계
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    • v.13 no.2
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    • pp.1-4
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    • 1964
  • Phase transformation is used to change some phase from phase in A.C. system. We have been used Scott or Fork connection in phase transformation the otherwise phase transformation was constructed from M-G set. From this M-G set, we could make phase shift facilities by mannual. Now, I can derive more easy phase transformation from taking another method. I believe this new phase transformation method in the first thing in the world. And so, I am going to explain about phase transformer construction process. The first, we could devide into equal part of core around the iron core as to be same size. The second, you will make primary and secondary winding on the core. The third, when you will supplied three phase A.C. at the terminal of primary winding you can get e.m.f. inducing of some phase at secondary. And so, we could make phase change from some phase A.C. We can apply this principle in many fields, i.e., freequency changer, phase leader of no use condenser, voltage regulator in keeping balance, and D.C. generator. And more, I will introduce in details concerning main pinciple and theory through following chapter.

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Comparisons between Skilled and Less-Skilled Players' Balance in Hakdariseogi (태권도 품새 우수·비 우수선수 간 학다리서기의 균형성 비교)

  • Ryu, Ji-Seon;Yoo, Si-Hyun;Park, Sang-Kyoon;Yoon, Suk-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.22 no.1
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    • pp.55-63
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    • 2012
  • The purpose of this study was to investigate the balance differences between skilled players and less-skilled players during Hakdariseogi motion of Keumgang Poomsae in Taekwondo. To achieve the study goal, total of 10 Taekwondo athletes; 5 skilled players(S, body mass: $67.0{\pm}5.7$ kg, height: $174.0{\pm}4.8$ cm, age: $20.0{\pm}2.0$ yrs) and 5 less-skilled players(LS, body mass: $73.0{\pm}4.9$ kg, height: $176.4{\pm}6.1$ cm, age: $20.8{\pm}1.3$ yrs) participated in this study. A three-dimensional motion analysis with 8 infrared cameras and one force plate whose sampling frequency as 30 Hz and 300 Hz, respectively, were performed. Participants' motion were divided into three phases which were preparation phase(P1), performing phase(P2) and maintaining phase(P3). The range and velocities of COP, the range and RMS of ground reaction torque and displacement between COM and center of BOS of each phase were computed. In this study, at P1 and P3 which were double and single stance, respectively, the range and M-L velocities of COP revealed significantly higher in LS compared with those of S(p<.05). At P2 which was single stance, LS indicated significantly higher in range of COP and ground reaction torque, and M-L velocities of COP than those of S(p<.05). The significantly shorter displacement between COM and center of BOS, however, was found in LS compared with that of S(p<.05). The results from our study indicated that S revealed more stable performance and a better posture control ability during performing Hakdariseogi motion.

Analysis of the Esterification Process for Poly(ethylene terephthalate)

  • Ahn, Young-Cheol;Park, Soo-Myung
    • Macromolecular Research
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    • v.11 no.6
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    • pp.399-409
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    • 2003
  • The first esterification reactor in the continuous polymerization of poly(ethylene terephthalate) has been analyzed by solving the material balances for the two-phase system with respect to the solubility of terephthalic acid. The Newton-Raphson method was used to solve the material balance equations instead of the Simplex method that is frequently used for finding a minimum point of a residual rather than a solution of an equation. A solution for the material balance equations, with the constraint of non-zero liquid phase fraction, could not be obtained with the solubility data of Yamada et al., but could be obtained with solubilities over a minimum value that is larger than their data. Thus, the solubility data of Yamada et al. are considered to be too small. On the other hand, the solubility data of Baranova and Kremer are so large that they gave a solution with the liquid phase only. Based on our results, several typical solubility curves satisfying the constraint of a non-zero liquid phase fraction are suggested in this study; we studied the reaction characteristics of the system using these curves. A higher temperature and a lower pressure are preferred for reducing the content of diethylene glycol.

Effects of Functional Resistance Training on Gross Motor and Balance Abilities in Children with Dyskinetic Cerebral Palsy : Single Case Design (기능적인 저항훈련이 운동이상형 뇌성마비 아동의 대동작과 균형능력에 미치는 영향 : 단일사례설계)

  • Kwon, Haeyeon
    • Journal of The Korean Society of Integrative Medicine
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    • v.4 no.3
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    • pp.109-119
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    • 2016
  • Purpose : The purpose of this research is to find clinical effects of functional resistance training using weighted vest on gross motor and balance abilities of children with dyskinetic cerebral palsy. Methods : This study selects 3 subjects for 8~12 years old who were diagnosed with children with dyskinetic cerebral palsy. The Design is ABA design of single-subject research design. Baseline(A) and TypeII Baseline(A : 12weeks) phases were received with NDT treatment, Intervention(B : 12weeks) phase provided with 40 minute functional resistance training using weighted vest in a session twice a week. In order to analyze the measure results of gross motor function and performance, balance abilities in children dyskinetic cerebral palsy during baseline, intervention and typeII baseline phase. Result : A statistically significant differences in the total GMFM including walking/running/jumping during baseline, intervention, typeII baseline, but no significant differences in the lying/rolling, sitting, crawling/kneeling and standing. A statistically significant differences in the total GMPM including dissociated movement, coordination, weight shift, stability during baseline, intervention, typeII baseline, but no significant differences in the body alignment domains. A statistically significant differences in the length and surface area ellipse of center of pressure during baseline, intervention, typeII baseline. Conclusion : The intervention method to facilitate multi-joint and closed kinematic chain movement equipped weighted vest applied functional resistance training on children with dyskinetic cerebral palsy effectively improve on gross motor function and performance, balance abilities.