• 제목/요약/키워드: Neutral System

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STEP 표준을 이용한 제품설계-제조 연계 방안

  • 강무진
    • Proceedings of the CALSEC Conference
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    • 2001.02a
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    • pp.531-544
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    • 2001
  • ■ Representing tolerance information together with feature and geometry information in neutral format (using STEP AP 203 and AP 224) ■ Preprocessor of a CAPP System ■ System-independent Interfacing of CAD and CAPP. (omitted)

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Effect of the Changes in Forward Head Posture and Neutral Head Posture on Respiratory (전방머리자세와 중립자세에 대한 인위적 자세변화가 호흡에 미치는 영향)

  • Bae, Wonsik;Lee, Keoncheol;Park, Seungwook;Baek, Yonghyeon
    • Journal of The Korean Society of Integrative Medicine
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    • v.5 no.1
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    • pp.67-74
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    • 2017
  • Purpose : Forward head posture is typical neck disorders occur in all people. And this attitude causes a shortening and weakening of the muscles in the body. It also causes excessive extension acts as a reward. This attitude has to change if the pain occurs around the neck and shoulders, and are subjected to unusual stress. Patients with chronic neck pain associated with forward head posture was found to be the more severe the fall of the respiratory, forward head posture poor quality of much breath. The purpose of this study was to compare the effect of changes in forward head posture and neutral head posture on respiratory. Method : Forty volunteers were participated in study and divided into two groups [forward head posture group (n=20) and neutral head posture group (n=20)]. We measured cervical alignment with global postural system to find out a forward head posture. Respiratory function was measured with a SPIROVIT SP-1 equipment and we found out a forced vital capacity (FVC), forced expiratory volume at one second (FEV1) and FEV1/FVC. A pared t-test was used to determine a statistical significance for the pulmonary function variation and a independent t-test was used to determine a statistical significance in the two groups. Results : In the experimental group, FVC and FEV1 were significantly higher in the artificial neutral head posture than in the forward head posture. In the control group, FVC and FEV1 were significantly higher in the neutral head posture than in the forward head posture. FVC, FEV1, and FEV1/ FVC were significantly higher in the neutral head posture of control group than the artificial neutral head posture of experimental group and higher in the artificial forward head posture of control group than the forward head posture of experimental group. Conclusion : In conclusion, neutral head posture is considered to be an important factor in correct posture and improvement of lung function and continuous study of posture correction program for posture imbalance will be needed.

ASYMPTOTIC STABILITY OF LINEAR SYSTEM OF NEUTRAL TYPE WITH TIME-VARYING DELAY

  • Park, Ju-H.
    • Journal of applied mathematics & informatics
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    • v.8 no.1
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    • pp.297-303
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    • 2001
  • In this paper, the problem of the stability analysis for a class of linear neutral systems with time-varying delay is investigated. Using the Lyapunov method, a delay-dependent sufficient condition for asymptotic stability of the systems in terms of linear matrix inequalities (LMIs) is presented. The LMIs can be easily solved by various convex optimization algorithms.

A Study on the Single-Phase PWM Rectifier with Neutral Leg (중성점을 가진 단상 PWM 정류기에 관한 연구)

  • 최연옥;김평호;한엄용;이진섭;조금배
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.675-679
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    • 1999
  • A single-phase PWM current source rectifier with a neutral leg is presented and throughly analyzed in this paper. This novel topology is implemented by adding an extra leg a step-down single phase PWM space vector modulation method to reduce the dc output voltage harmonics is proposed. The PWM pattern generation need a digital system. As compared with a conventional single-phase PWM rectifier, over 20% improvement of the total harmonics distortion in the output voltage can be obtained. Different SVM techniques are analyzed for this PWM rectifier and simulation result are presented.

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NOT ALL PAC IS SUITABLE

  • Zhi, Chen-Yun;Su, Xie-Lai
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.04b
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    • pp.390-393
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    • 1999
  • In this paper, a series of PAC (polyaluminum chloride) samples were prepared for rosin neutral sizing system. Some characters of PAC were discussed in detail. The experimental results show that it is possible to achieve neutral sizing when PAC is compounded with DRS (dispersed rosin size) instead of alum (aluminum sulfate).

CONTROLLABILITY RESULTS FOR IMPULSIVE NEUTRAL EVOLUTION DIFFERENTIAL SYSTEMS

  • Selbi, S.;Arjunan, M. Mallika
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.2
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    • pp.93-105
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    • 2012
  • In this paper, we consider the controllability of a certain class of impulsive neutral evolution differential equations in Banach spaces. Sufficient conditions for controllability are obtained by using the Hausdorff measure of noncompactness and Monch fixed point theorem under the assumption of noncompactness of the evolution system.

EXISTENCE AND STABILITY RESULTS FOR STOCHASTIC FRACTIONAL NEUTRAL DIFFERENTIAL EQUATIONS WITH GAUSSIAN NOISE AND LÉVY NOISE

  • P. Umamaheswari;K. Balachandran;N. Annapoorani;Daewook Kim
    • Nonlinear Functional Analysis and Applications
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    • v.28 no.2
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    • pp.365-382
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    • 2023
  • In this paper we prove the existence and uniqueness of solution of stochastic fractional neutral differential equations with Gaussian noise or Lévy noise by using the Picard-Lindelöf successive approximation scheme. Further stability results of nonlinear stochastic fractional dynamical system with Gaussian and Lévy noises are established. Examples are provided to illustrate the theoretical results.

Hydrogen Metabolism in Clostridium acetobutylicum Fermentation

  • J.Gregory Zeikus
    • Journal of Microbiology and Biotechnology
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    • v.2 no.4
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    • pp.248-254
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    • 1992
  • The initial growth of Clostridium acetobutylicum was not inhibited by 1 atm of H$_2$ while H$_2$ reduced glucose consumption in a solventogenic culture of a phosphate limited 2-stage chemostat. Under 1 atm of H$_2$, a solventogenic culture consumed hydrogen, but an acidogenic culture produced hydrogen. H$_2$ consumption by the solventogenic culture was enhanced by the addition of 5 mM neutral red, an artificial electron carrier with a redox potential of -325 mV. Hydrogenase activity, measured in both directions of production and consumption, showed that activity coupled with methyl viologen is higher in an acidogenic culture than in a solventogenic culture, and that the two cultures have similar activities for methylene blue reduction. The solventogenic culture showed a higher activity coupled with neutral red than the acidogenic culture. From these results, it is hypothesized that hydrogen producing hydrogenase activity is high during the acidogenic phase, and decreases as solventogenesis starts, and that the solventogenic culture produces a second hydrogenase which uses an electron carrier other than ferredoxin. This hypothesis was supported by the fact that enzyme activities involved in electron flow can be coupled to neutral red, indepedent of ferredoxin, and that neutral red addition to the fermentation system increased butanol yield, with a decrease in production of less reduced fermentation products, and $H^2$.

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A Novel Three-Phase Four-Wire Shunt Active Filter to Eliminate Neutral Current (高調波 中性電流를 低減시키기 위한 3相4線 竝列形 能動필터에 關한 硏究)

  • 고경수;김래기;유권종;송진수;김시경
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.3
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    • pp.184-190
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    • 1998
  • Most buildings and factories are supplied with electric power by three-phase four-wire low voltage electric distribution system. This method pollutes the neutral line and utility sources with harmonic currents. Today, development of power conversion technology and the popularization of computer cause the neutral current to become serious. In this paper, a novel three-phase four-wire active filter is proposed to solve these harmonic problems has two purposes. The first purpose of the proposed active filiter is that the phase current has a sinusoidal waveform shape under the nonlinear load. The second purpose of the proposed active filiter is that the current on the neutral line become zero under the unbalanced power source and under the varring load conditions. The ability of the shunt active filiter has been proved to be excellent through simulations under the varring load conditions.

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A Three Phase Three-level PWM Switched Voltage Source Inverter with Zero Neutral Point Potential

  • Oh Won-Sik;Han Sang-Kyoo;Choi Seong-Wook;Moon Gun-Woo
    • Journal of Power Electronics
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    • v.5 no.3
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    • pp.224-232
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    • 2005
  • A new three phase three-level Pulse Width Modulation (PWM) Switched Voltage Source (SVS) inverter with zero neutral point potential is proposed. It consists of three single-phase inverter modules. Each module is composed of a switched voltage source and inverter switches. The major advantage is that the peak value of the phase output voltage is twice as high as that of a conventional neutral-point-clamped (NPC) PWM inverter. Thus, the proposed inverter is suitable for applications with low voltage sources such as batteries, fuel cells, or solar cells. Furthermore, three-level waveforms of the proposed inverter can be achieved without the switch voltage imbalance problem. Since the average neutral point potential of the proposed inverter is zero, a common ground between the input stage and the output stage is possible. Therefore, it can be applied to a transformer-less Power Conditioning System (PCS). The proposed inverter is verified by a PSpice simulation and experimental results based on a laboratory prototype.