• Title/Summary/Keyword: droop

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A Study on The Obese Breast Shape of 20′s Women (20대 비만여성의 유방형태 분석)

  • 손희순;고태희
    • The Research Journal of the Costume Culture
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    • v.8 no.2
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    • pp.282-292
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    • 2000
  • The purpose of this study is to provide for some basic data useful to the development of the brassieres comfortable and more suitable for obese women. The results of this study can be summarized as follows ; 1. Obese women were categorized using Rohrer index into three groups, and thereupon, their breast forms were analyzed. As a result, it was found that group 1 and 2 had similar small breasts, while group 3 had the largest size of breasts. 2. The forms of obese women's breast split, protrusion and volume, factors related with breast area and drooping, factor affecting the breast protrusion and factor defining the lower form of breast. 3. The actual breast types of obese women could be classified into cone type, protrusion type, drooping type Ⅰ and Ⅱ. The more obese a woman was, her breast tended more to droop.

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Controller Design for Stable Engine Idle Mode (안정한 엔진 공회전 모드를 위한 제어기 설계)

  • 이영춘;방두열;이성철
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.6
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    • pp.89-95
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    • 2000
  • The engine idle speed mode becomes worse as one drives a vehicle for several years. This is due to ageing of engine and power-train parts. In this case, unstable idle conditions such as engine stall and droop are frequently experienced when the engine gets heavy torque loads due to power steering pump and air conditioning compressor. The objective of this paper is to study on the idle speed control using PID controller under load disturbances. The input of the PID controller is an error of rpm. The output of the PID controller is an ISCV duty cycle. The dSPACE Controller Boards are used to interface with engine. The on-vehicle test is realized using by SIMULINK and BLOCKSETS tools. The real time interface control panel supplied by Control Desk S/W is designed to have good results in engine idle speed control.

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An Improvement of Voltage Disturbances for Fuel Cell Systems (연료 전지 시스템의 전압왜란 개선)

  • Moon Hyun-Wook;Jeong Eun-Jin;Kim Yoon-Ho
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.5
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    • pp.245-252
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    • 2005
  • The fuel cell systems are one of very useful energy sources. The systems have advantages as renewable and environmental sources. To obtain AC components from fuel cells, it needs inverters. A multilevel converter is used as a power conversion system for a high power fuel cell system. Through harmonic analysis, it is shown that the harmonic components and THD increase while a fundamental component of output decreases as voltage droop increases. To solve the voltage disturbance problems, three different approaches are investigated in this paper; installation of a boost converter at the fuel cell output, control of pulse widths, and use of ultracapacitors. The proposed three approaches are analyzed and compared through simulation and experimental results.

The Effect of Wind Turbine fe the Frequency of Isolated Systems (단독계통에서 풍력발전기의 주파수 영향 분석)

  • Hwang, Kyo-Ik;Chun, Yeong-Han
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.143-145
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    • 2005
  • There has been increasing interest in the renewable energies. Wind energy is worldwide number one renewable energy from the installed capacity viewpoint. Most of the power systems utilizing wind energy are connected to other large systems. In such integrated systems, frequency control is not big issue. Rut the situation is different in isolated systems like Korean power system. It is important to assess appropriate capacity of wind power for our system, as it affects the system operation and control strategy. In this paper we made it clear the relationship among generator inertias, governor droop, system damping and wind energy capacity.

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The Study on the Aeroelastic Stability of Hingeless Helicopter Rotor in Hover Considering Parametric Angle Changes (파라메타 각 변화를 고려한 힌지없는 헬리콥터 로우터의 공력탄성학적 안정성)

  • 한창헌;김승조
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.386-391
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    • 1998
  • The effect of the changes in parameter angles(precone, droop, sweep) on the lead-lag damping was focused on. Experiment was made with hingeless 4-blade rotors and NACA 0012 airfoil. For the measurement of the rotating natural frequencies and lead-lag damping, non-rotating swash plate was oscillated at the regressing lag mode frequency and the data were acquired after the excitation was cut off. Analysis was made using a finite element formulation based on Hamilton's principle. The main blade is assumed as elastic beams. Quasi-steady strip theory is used to obtain aerodynamic forces, and non-circulatory forces are also included.

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A Research on the Somatotypes of Female College Students

  • Kwon, Sook-Hee
    • International Journal of Human Ecology
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    • v.8 no.1
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    • pp.19-26
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    • 2007
  • The object of this research was to observe the female college 220 students of aged 19-24 for four years and to examine somatotypes distribution; this research intends to contribute to the fitness of clothes by studying the body distribution that affects the clothing structure. The measurement and wearing experiment for somatotypes are done years annually. The average, standard deviation and coefficient of variation was calculated by the SAS program. The research results are as follows: The three somatotypes of side view silhouette (straight type, bend-forward type, lean-back type) showed fairly even distribution. As a result of dressing experiment with the basic bodice pattern, the most influential factor on its suitability was found to be the neck area, shoulder and ease of bodice respectively. The partial body types to observe were categorized as: shoulder(normal, slope, squared), bust(A cup, B cup, C cup), hips (normal, droop, projecting). As for the result for full body type by BMI, normal type was most dominant, and for the categorization by drop, the type A which is with small breasts and large hips was most prevalent.

CIC 필터의 통과대역 특성개선을 위한 저전력의 4차 보간필터

  • 장영범;양세정
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.497-500
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    • 2003
  • In this paper, a new filter structure to improve frequency response characteristics in CIC(Cascaded Integrator-Comb) decimation filters is proposed. Conventional filters improve passband characteristics, but they make worse slinging band characteristics. In this paper, we propose a new filter which is called IFOP(Interpolated Fourth-Order Polynomials). By using this proposed filter, passband droop and aliasing band attenuation are simultaneously improved. Since proposed filter needs only one multiplication computation is not much. And overall linear phase characteristics are maintained since the proposed filter is also linear phase. Finally, implementation cost of the proposed filter is compared with those of conventional filters.

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Parallel operating technique for the stand alone PV PCS (독립형 태양광 인버터의 병렬 운전 기법)

  • Jeong, Ku-In;Kwon, Jung-Min
    • Journal of the Korean Solar Energy Society
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    • v.35 no.6
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    • pp.9-15
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    • 2015
  • In this paper, a parallel operating technique for the stand alone photovoltaic (PV) power conditioning system (PCS) is proposed. The proposed parallel operating technique can increase the power rating of the system easily. Also, it provide three-phase connection function. The proposed technique does not separated master and slave system. Also, it does not use the separated synchronization line. Therefore, the PCS can supply continuous power even if one of the PCS breaks down. This technique is composed of a phase locked loop (PLL) control, droop control, current limit control and etc. Experimental result obtained on 2-kW prototype to verify the proposed technique.

Analog CMOS Performance Degradation due to Edge Direct Tunneling (EDT) Current in sub-l00nm Technology

  • Navakanta Bhat;Thakur, Chandrabhan-Singh
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.3 no.3
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    • pp.139-144
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    • 2003
  • We report the results of extensive mixed mode simulations and theoretical analysis to quantify the contribution of the edge direct tunneling (EDT) current on the total gate leakage current of 80nm NMOSFET with SiO2 gate dielectric. It is shown that EDT has a profound impact on basic analog circuit building blocks such as sample-hold (S/H) circuit and the current mirror circuit. A transistor design methodology with zero gate-source/drain overlap is proposed to mitigate the EDT effect. This results in lower voltage droop in S/H application and better current matching in current mirror application. It is demonstrated that decreasing the overlap length also improves the basic analog circuit performance metrics of the transistor. The transistor with zero gate-source/drain overlap, results in better transconductance, input resistance, output resistance, intrinsic gain and unity gain transition frequency.

Transient Stability Enhancement under Microgrid Environment using P-w Droop Control for Inverter-based Distributed Generation (마이크로그리드 환경에서 인버터기반 분산전원의 P-w 드룹 제어를 통한 과도안정도 향상 대책)

  • Lee, Young-Woo;Kim, Seung-Wan;Jin, Young-Gyu;Yoon, Yong-Tae
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.149-150
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    • 2015
  • 소규모 분산전원 및 에너지 저장장치로 구성된 마이크로그리드는 에너지 자급자족이 가능한 특징을 가지며 계통연계 혹은 독립운전 모드로 운전이 가능하다. 마이크로그리드를 계통연계 모드로 운전하는 경우, 상위 계통에서 사고 발생 시 마이크로그리드 내 동기기의 과도안정도 문제가 발생할 수 있다. 이 때 인버터 기반 분산전원의 빠른 응답 속도를 활용하면 인접 동기기의 유효출력을 효과적으로 제어하여 계통연계 모드를 유지하면서도 과도안정도를 유지할 수 있다. 본 연구에서는 인버터 기반 분산전원의 P-w 제어를 통해, 정상 운전시에는 정해진 전력을 공급하면서 사고 시에는 인접 동기기의 과도안정도를 향상시킬 수 있는 제어 방법을 제안하였다. 또한 실제 적용 가능성을 확인하기 위해 ATP/EMTP프로그램을 이용하여 계통을 구성하고 해석하였다.

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