• Title/Summary/Keyword: Control of separation

Search Result 1,035, Processing Time 0.031 seconds

Effectiveness of Continuous Deflective Separation System to Control Nonpoint Source Pollution from Urban Areas (도시지역 비점오염원 관리를 위한 와류필터형 처리시설의 효율성 연구)

  • Park, Jong-Sik;Koh, Jeung-Hyun;Kim, Sang Keun;Chung, Ha-Ik
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.10 no.6
    • /
    • pp.88-98
    • /
    • 2007
  • The control of nonpoint source pollution from the urban paved areas with high imperviousness in is required to improve the water quality of aquatic resources. This research investigated the characteristics of urban runoffs and evaluate the effectiveness of the continuous deflective separation systems for stormwater best management practice. The systems were installed in the vicinity of a high-level road, an apartment complex, and the Cheonggye stream. Stormwater runoff was sampled in these sites. Biochemical oxygen demand ($BOD_5$), total suspended solid (TSS), total nitrogen (T-N), and total phosphorus (T-P) were analyzed. The removal efficiency of $BOD_5$, TSS, and T-P for the road was 10.9-81.0%, 11.7-93.4%, 0-37.5%, respectively. That of $BOD_5$, TSS, T-N, and T-P for the complex was 12.5-65.8%, 26.5-77.6%, 1.8-28.7%, and 20.0-37.5%, respectively. The abatement efficiency $BOD_5$, TSS, T-N, and T-P for the stream was 7.2-85.2%, 41.7-98.2%, 11.3-65.6%, and 2.0-71.5%, respectively. This study shows that the systems can be used to remove $BOD_5$ and TSS from urban runoffs efficiently.

Numerical Study on Flow Characteristics of Synthetic Jet with Rectangular and Circular Slot Exit (사각형 및 원형 출구 Synthetic Jet의 유동 특성에 대한 수치적 연구)

  • Kim, Min-Hee;Kim, Woo-Re;Kim, Chong-Am;Jung, Kyung-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.7
    • /
    • pp.585-595
    • /
    • 2011
  • The flow characteristics of synthetic jet depending on rectangular and circular jet exit configuration are investigated using numerical computation with cross flow. In rectangular slot, synthetic jet generates the strong vortex but supplies fewer momentum and effectiveness of flow control is reduced along flow direction. In circular slot, regular vortex is formed from slot center to end. It affects the wider region than rectangular slot. The distribution of wall shear stress is considered in order to indicate the effectiveness of flow control device for flow separation delay. Consequently, circular slot is a more suitable candidate for delaying flow separation. In order to derive the optimal shape of a circular slot exit, hole gap and diameter that affect the flow structure and flow control were analyzed. As a result, consider the hole diameter and gap of circular slot exit design, effectiveness of the flow control can be increased.

HF-Band Wireless Power Transfer System with Adaptive Frequency Control Circuit for Efficiency Enhancement in a Short Range (근거리에서 효율 향상을 위해 적응 주파수 제어 회로를 갖는 HF-대역 무선 전력 전송 시스템)

  • Jang, Byung-Jun;Won, Do-Hyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.22 no.11
    • /
    • pp.1047-1053
    • /
    • 2011
  • In this paper, we proposed an HF-band wireless power transfer system with adaptive frequency control circuit for efficiency enhancement in a short range. In general, a wireless power transfer system shows an impedance mismatching due to a reflected impedance, because a coupling coefficient is varied with respect to separation distance between two resonating loop antennas. The proposed method can compensate this impedance mismatching by varying input frequency of a voltage-controlled oscillator adaptively with respect to separation distance. Therefore, transmission efficiency is enhanced in a short distance, where large impedance mismatch occurs. The adaptive frequency circuit consists of a directional coupler, a detector, and a loop filter. In order to demonstrate the performance of the proposed system, a wireless power transfer system with adaptive frequency control circuits is designed and implemented, which has a pair of loop antennas with a dimension of 30${\times}$30 $cm^2$. From measured results, the proposed system shows enhanced efficiency performance than the case without adaptive frequency control.

Error comparison of the computation ratios in SDINS (SDINS의 계산 시간간격 비에 따른 오차해석)

  • 위상규;박춘배
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1986.10a
    • /
    • pp.295-297
    • /
    • 1986
  • In this study, the strap down INS on an earth satellite launch vehicle is simulated with different computing cycles between processing the IMU signals and the navigation computation. At the time of separation of booster, error are discussed. The acceptable computing cycles can be determined by simulation.

  • PDF

Compensation of Network Delay Using Predictive Controller (예측제어기를 이용한 네트워크 시간지연 보상)

  • 허화라;박재한이장명
    • Proceedings of the IEEK Conference
    • /
    • 1998.06a
    • /
    • pp.243-246
    • /
    • 1998
  • A predictive controller is designed based upon stochastic methods for compensation of network time delay which caused by the spatial separation between controllers and actuators. Current commands are generated by using time varying probability functions which can be defined according to the values of previous control inputs and actual outputs. To demonstrate the effect of this control methodology, simulation experiments are performed. The results show that even an unstabilized system by a long time delay can be stabilized with this predictive controller.

  • PDF

Digita Redesign of Observer-Based Output Feedback Controller

  • Lee, Ho-Jae;Park, Jin-Bae;Cho, Kwang-Lae;Joo, Young-Hoon
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2002.10a
    • /
    • pp.64.5-64
    • /
    • 2002
  • This paper concerns a new digital redesign (DR) technique for an observer-based output-feedback control (OBOFC) system. The term DR involves converting an analog controller into an equivalent digital one in the sense of state-matching. The considered DR problem is formulated as convex minimization problems of the norm distances between linear operators to be matched. The stability condition is easily embedded and the separation principle on the DR of the OBOFC is explicitly shown. A numerical example is included for visualizing the feasibility of the proposed technique.

  • PDF

Effect of Membrane Fouling due to Micro-organism Growth on the Membrane Surface (막면 세균 증식에 의한 막오염에 관한 연구)

  • Kim, Hyung Soo
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.13 no.3
    • /
    • pp.36-41
    • /
    • 1999
  • High quality drinking water can be produced by membrane separation process. A major problem in the current system is a membrane fouling control. In order to investigate membrane fouling due to E.coll removal, lab scale experiment using MF and UF and semi pilot plant experiment using UV radiation or not was performed. AS a result, the possibility of membrane fouling control by repressing of micro-organism on the membrane surface was clearly verified. But it was not clearly verified in this experiment the combined effect with other factors such as Turbidity, organic and inorganic matters.

  • PDF

Past and ongoing researches for magnetic force control technology

  • Mori, T.;Nishijima, Shigehiro
    • Progress in Superconductivity and Cryogenics
    • /
    • v.18 no.1
    • /
    • pp.23-27
    • /
    • 2016
  • The technologies using magnetic force control have been investigated toward application in various fields. Some of them have been put into practical use as the results of technological development. This paper introduces our technical development in the field of water processing, scale removal, magnetic drug delivery system, decontamination of radioactive substances and resources recycling.

Trust Building in Cyberspace (사이버 공간에서의 신뢰성 확보 방안 - 기업 내부관점에서 -)

  • Park, Gyeong-Hwan
    • 한국디지털정책학회:학술대회논문집
    • /
    • 2003.12a
    • /
    • pp.403-415
    • /
    • 2003
  • This study is performed to examine the relationships between trust and antecedents in cyberspace. Trust is the major control system in cyberspace. Different time, different spaces, different cultures, indistinct boundaries, flexible structure, separation of information from matters, cybernetics, difficulty of control are differential characteristics between cyberspace and physical space. Providing fit information, use of effective electronic channels, previous trust management, feedback system about output, flexible culture, self-regulation, off-line meeting, providing information about tasks and roles, ability, and justice are supposed to have effects on trust in cyberspace. By electronic mediated systems, the company will have more business opportunity. But trust will be conditional factors of expanding business in cyberspace.

  • PDF

Trajectory and Attitude Analysis for the 1st Flight Test of KSLV-I Launch Vehicle (나로호 발사체 1차 비행시험에서의 궤적 및 자세 분석)

  • Roh, Woong-Rae;Cho, Sang-Bum;Ko, Jeong-Hwan;Sun, Byung-Chan;Kim, Jeong-Yong;Park, Jeong-Joo;Cho, Gwang-Rae
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.38 no.3
    • /
    • pp.213-220
    • /
    • 2010
  • This paper presents the analysis results of trajectory, performance and attitude control based on the first flight data of the KSLV-I. The KSLV-I had a fairing separation problem and failed to inject spacecraft into the orbit. In this paper, the trajectory, flight performance, and attitude control was analyzed considering the influence of unseparated fairing. Moreover, the flight results and performance of the inertial navigation and guidance system were presented. As a results of post-flight analysis, any other problem besides the fairing separation problem was not happened and onboard equipment functioned normally.