• Title/Summary/Keyword: Change point

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Effects of the High-Heeled Shoes on the Sensory System and Balance in Women (높은 굽 신발이 감각계의 변화와 균형에 미치는 영향)

  • Kim, Won-Ho;Park, Eun-Young
    • Physical Therapy Korea
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    • v.4 no.2
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    • pp.10-17
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    • 1997
  • The purpose of this study were to compare light touch, two-point discrimination, position sense, and static balance ability and to examine the relationship of static balance ability and different senses in those who are wearing various heights of high-heeled shoes. Each 29 women was classified two different heights (below 3 cm, above 7 cm) by experience in wearing shoes. A t-test was used to determine the differences between low- and high-heeled shoe in light touch, two-point discrimination, position sense, and static balance ability. Pearson correlation was used to examine the relationship of static balance ability to these sensation. The results were as follows: 1) No significant differences in average light touch, position sense between two groups were found(p>0.05). But significant differences in average two-point discrimination, static balance ability were found(p<0.05). 2) Static balance ability was not significantly correlated with light touch, position sense, two-point discrimination(p>0.05). The results suggest that long time experience in wearing high-heeled shoe may be caused local sensory change and decreased static balance ability. Even though, static balance ability was not significantly affected but correlated with two-point discrimination, position sense, and light touch in order.

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Variable Step Size Maximum Power Point Tracker Using a Single Variable for Stand-alone Battery Storage PV Systems

  • Ahmed, Emad M.;Shoyama, Masahito
    • Journal of Power Electronics
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    • v.11 no.2
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    • pp.218-227
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    • 2011
  • The subject of variable step size maximum power point tracking (MPPT) algorithms has been addressed in the literature. However, most of the addressed algorithms tune the variable step size according to two variables: the photovoltaic (PV) array voltage ($V_{PV}$) and the PV array current ($I_{PV}$). Therefore, both the PV array current and voltage have to be measured. Recently, maximum power point trackers that arc based on a single variable ($I_{PV}$ or $V_{PV}$) have received a great deal of attention due to their simplicity and ease of implementation, when compared to other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT algorithm using only a single current sensor for stand-alone battery storage PV systems. These methods utilize only the relationship between the PV array measured current and the converter duty cycle (D) to automatically adapt the step change in the duty cycle to reach the maximum power point (MPP) of the PV array. Detailed analyses and flowcharts of the proposed methods are included. Moreover, a comparison has been made between the proposed methods to investigate their performance in the transient and steady states. Finally, experimental results with field programmable gate arrays (FPGAs) are presented to verify the performance of the proposed methods.

A study on the Prevention of Malfunction by Developing Mechanical Sensing device of Railway Point (철도 선로전환기 기계식 밀착검지기 개발을 통한 장애경감에 관한 연구)

  • Yu, Jae-Hyeon;Sin, Myeong-Ho
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.404-409
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    • 2007
  • To change rail tracks from main track to another track, it needs some device that is called turnout point. If the point which is composed of accurate parts and complex sensors does not work, serious problems will be arisen. However, there serious problems by the failure of the point. In this paper, after analyzing the failures of the conventional points, a new point is presented. The proposed point is not affected by surge caused by lighting.

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A Study on the Three Dimensional Statistical Turbulent Flow Characteristics Around a Small-Sized Axial Fan for Refrigerator (냉장고용 소형 축류홴의 통계학적 3차원 난류유동 특성에 관한 연구)

  • Kim, Jang-Gwon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.6
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    • pp.819-828
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    • 2001
  • The operating point of a small-sized axial fan is strongly dependent upon the system resistance. Therefore, the turbulent flow characteristics around a small-sized axial fan may change significantly according to the operating point. This study represents three-dimensional turbulent flow characteristics around a small-sized axial fan measured at the ideal design point $\phi$=0.25, which is equivalent to the maximum total efficiency point, by using three dimensional fiber-optic type LDA system. This LDA system is composed of a 5 W Argon-ion laser, two optics in back-scatter mode, three BSAs, a PC, and a three-dimensional automatic traversing system. A kind of paraffin fluid is used to supply particles by means of fog generator. Mean velocity profiles downstream of a small-sized axial fan along the radial distance show that the streamwise and the tangential components exist in a predominant manner, while the radial component has a small scale distribution and shows the inflection which its flow direction is inward or outward. Moreover, the turbulent intensity profiles show that the radial component exists the most greatly among turbulent energies.

Effects on the thermal change of the Taeyon(L1) and the Chungbu(L1) area following acupuncture stimulation on Taeyon(L9) in man (태연(太淵)(L9)자침(刺鍼)이 태연(太淵)(L9)과 중부(中府)(L1)영역(領域)의 온도변화(溫度變化)에 미치는 영향(影響))

  • Kim, Young-ho;Song, Beom-Yong;Yook, Tae-han
    • Journal of Acupuncture Research
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    • v.18 no.5
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    • pp.77-91
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    • 2001
  • Backgrounds and purpose : The acupuncture of oriental medicine is very important in treatments. Until now it was been researched according to the meridian and qi xue(氣血) phenomenon of oriental medicine's theory. Acupuncture will show more objective index to observe the meridian. And then, I studied the effects on the thermal change of the Taeyon($L_9$) and Chungbu($L_1$) following acupuncture stimulation. Objective and Methods : This study was performed from December 1999 to February 2000 on 60 healthy students. The objective was divided into two groups, those are the control group A(N=30) that no acupuncture stimulation, the group B(N=30) of acupuncture stimulation on Taeyon($L_9$). First, in the control group A, I took a picture Taeyon($L_9$) Chungbu($L_1$) Taenung($P_7$) Chondol($CV_{22}$) area for 30 men without any stimulation with the Digital Infrared Thermograph Imaging(D.I.T.l.) and did same area, 10min after. Second, in the acupuncture stimulation group B, we took a picture Taeyon($L_9$) Chungbu($L_1$) Taenung($P_7$) Chondol($CV_{22}$) area for 30 men without any stimulation with the Digital Infrared Th - ermograph Imaging(D.I.T.I.), and then stimulate acupuncture on Taeyon($L_9$) and took a picture same area, 10min after. Results : 1. In healthy men, average skin temperture on Taeyon($L_9$) area was lower than Chungbu($L_1$) area about $3.0^{\circ}C$, in the Lt. Taeyon($L_9$) and Chungbu($L_1$) area was lower than Rt. Taeyon($L_9$) and Chungbu($L_1$) area. 2. In the acupuncture stimulation group B, the skin temperature of both side Taeyon($L_9$) area showed the increase or decrease significantly. But both Taenung($P_7$) area did not showed significantly. 3. In the acupuncture stimulation group B, the skin temperature of both side Chungbu($L_1$) area showed the increase or decrease significantly. But both Chondol($CV_{22}$) area did not showed significantly. 4. The thermal changes of the area which is a meridian point in the Lung Meridian of the acupuncture stimulation group on Taeyon($L_9$) different from other Meridian with significantly change. Conclusion : The acupuncture stimulation on Taeyon($L_9$) affected the thermal change of the area which is a meridian point, in the Lung Meridian. And then I could relate these results with the existence of the meridian and meridian point. Thus, continuous thermographic study will be needed for the existence of the meridian and meridian point.

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Absorption Spectroscopic Studies of Prodigiosin Extracted from Serratia Marcescens Strain (Serratia marcescens 균주로부터 추출한 Prodigiosin의 흡수분광학적 연구)

  • Park, Hee-Aurk
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.1
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    • pp.355-361
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    • 2019
  • The red pigment extracted from Serratia marcescens 2354 (ATCC 25419) was prodigiosin (PG), which was dissolved in methanol and measured for ultraviolet and visible light absorption spectra. It was the typical absorption spectrum of PG in an acid solution with ${\lambda}_{max}=537nm$. When the concentration of PG was increased from $1.0{\times}10-5M$ to $9.0{\times}10-5M$ in the methanol solution, the absorption intensity at 537 nm was increased, the absorption intensity at 467 nm was decreased, and the isosbestic point at 500 nm was observed. This phenomenon can be regarded as a result of reversible acid-base equilibrium reaction considering 537 nm and 467 nm of PG absorption band in acid and base solution respectively and isosbestic point of 500 nm. On the other hand, when the concentration of PG was reduced from $6.0{\times}10-4$ to $1.0{\times}10-4M$ in acetic acid buffer solution at pH 4.75, a new absorption band with ${\lambda}$ max at 500 nm appeared. This absorption band appears only in the aqueous solution of pH 4.75 and does not appear in the pure methanol solution of the same pH. This is due to the conversion of the PG molecule from the ${\alpha}$-isomer to the ${\beta}$-isomer by $H_2O$. In other words, it was confirmed that the color change of the PG can be caused by the concentration of the solution and the characteristics of the solvent.

Effect of Acupuncture at Yintang Point(EX-$HN_3$) on Heart Rate Variability in Healthy Adults with Mental Stress (인당혈(印堂穴) 침자극이 정신적 스트레스를 가한 성인의 심박변이도에 미치는 영향)

  • Kim, So Jung;Kim, Nam Sik;Kim, Jong Yoon;Kim, Yong Suk;Nam, Sang Soo
    • Journal of Acupuncture Research
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    • v.29 no.6
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    • pp.47-56
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    • 2012
  • Objectives : This study was performed to investigate the effect of acupuncture at Yintang point(EX-$HN_3$) on heart rate variability in healthy adults with mental stress. Methods : 38 healthy volunteers(sham point group : 19, Yintang point group 19) participated in this study. The study was established by randomized trial. After 10 minutes rest period, mental stress was provided for 10 minutes. HRV was recorded before and after stress. And then simple acupuncture was applied at sham or Yintang point for 15 minutes. We measured HRV 3 times: before and after stress, and after acupuncture. Results : In sham point group, LF norm and HF norm changed significantly after mental stress. In Yintang point group, LF, HF, LF norm, HF norm and LF/HF showed a significant change after mental stress. In sham point group, all indicators were not affected after acupuncture. In Yintang point group, HF norm decreased significantly. LF, LF norm and LF/HF increased significantly. There were significant differences between two groups(p<0.05). Conclusions : The results suggest that acupuncture at Yintang point(EX-$HN_3$) can regulate and prevent the alteration of autonomic nerve system by mental stress.

Study on methodology about clinical effect of single point acupuncture in patients with hypertension (단일경혈을 이용한 침의 임상효과에 관한 방법론 연구 - 고혈압 환자를 중심으로 -)

  • Son, Yang-Sun;Yeo, Soo-Jung;Kim, Yoon-Ju;Park, You-Sun;Lim, Sabina
    • Korean Journal of Acupuncture
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    • v.29 no.1
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    • pp.23-36
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    • 2012
  • Objectives : This study was conducted to investigate effective treatment point selection method using oppressive pain in acupoints as elementary attempt for standard methodology of clinical acupuncture studies. Methods : Twenty seven subjects with hypertension or within prehypertension category - systolic and diastolic blood pressure (BP) over 120/80mmHg - were divided into two groups, oppressive pain point treatment group and oppressive painless point treatment group. In oppressive pain point treatment group, single point acupuncture (SPA) was conducted for 16 sessions during 8 weeks on most oppressive painful point among 6 selected acupuncture points used in previous trials and clinic. As a SPA intervention, 15 minutes with deqi sensation- elevating manipulation was conducted on the treatment acupoint. Same process was conducted in oppressive painless point treatment group on most oppressive painless point with subject blinding. Results : Significant reduction was observed in both systolic and diastolic BP after short time intervention (15.5/8.8 mmHg, 10.7/7.1 mmHg, P<0.05, respectively at 1 week) and maintained for 8 weeks intervention period in all groups (12.8/8.0 mmHg, 19.4/12.6 mmHg, P<0.05, respectively). No significant difference of BP change between oppressive pain point treatment group (N=10) and oppressive painless point treatment group (N=9) was observed during 8 weeks study period. Conclusions : SPA treatment as used in this pilot study was effective for lowering BP in mild hypertensive population, but oppressive pain in acupoint had no effect on treatment. This present result suggests the possibility of SPA for hypertension treatment regardless of oppressive pain.

The change of critical current with crack formation in a Bi-2223/Ag tape (크랙에 의한 Bi-2223/Ag 테이프의 임계전류 변화)

  • 박을주;설승윤
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.249-252
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    • 2002
  • The change of critical current with a crack formation in a Bi-2223/Ag tape was studied by experimental and numerical analyses. Critical current of Bi-2223/Ag tape was measured with a continuous DC-power supply. The current-voltage relation of a Bi-2223/Ag tape is measured by the four point method. Numerical method is used to solve two dimensional heat conduction equation. By comparing the experimental and numerical results, the validity of numerical method is verified.

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An Analysis Method of Accelerated Life Test Data with a Change of Failure Mechanism (가변 고장메카니즘을 가진 가속수명시험 데이타 분석방법)

  • Won, Y.C.;Kong, M.B.
    • Journal of Korean Institute of Industrial Engineers
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    • v.20 no.1
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    • pp.39-51
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    • 1994
  • Almost all accelerated life tests assume that no basic failure mechanism changes within the test stresses. But accelerated life test, considering failure mechanism changes, is needed since failure mechanism changes when accelerating beyond the used stress. This paper studies the analysis when the failure mechanism changes within the test stresses. The piecewise linear regression, which the join point of two lines is estimated, is applied In particular, two accelerated life tests, with and without a change in failure mechanism are examined.

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