• Title/Summary/Keyword: Loop

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A STUDY ON THE CHANGES OF THE ELASTIC PROPERTIES TN LOOPED WIRES BY VARIABLE FACTORS (변환요소에 따른 LOOPED WIRE의 탄성 변화에 관한 연구)

  • Na, Yong-In;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.25 no.3
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    • pp.263-271
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    • 1995
  • The purpose of this study nab to evlauate and compare the effect of the variable factors of wire on the elastic properties of looped rectangular wire. Five variable factors were presented-material(Hi-T, blue Elgiloy), wire size(.016'$\;\times\;$.022', .018'$\;\times\;$.025'), loop length(15mm, 20mm), loop configuration(open loop, closed loop), gabling (non-gable, gable). So, the total 256 specimens were divided into 32 groups, and each of those nab pulled on Instron testing machine. The load-deflection curve of each wire obtained, from which force, range in elastic limit, and stiffness were computed and analyzed statistically. The results were obtained as follows : 1. All of the variable factors - wire material, size, loop length loop configuration, and gabling - took a significant effect on load-deflection rate of looped wire. 2. The force at elastic limit was the smallest in the group of Hi-T, .016'$\;\times\;$.022', 20mm loop length, open loop, non-gable, and the largest in the group of blue Elgiloy, .018'$\;\times\;$.025', 15mm loop length, closed loop, non-gable. 3. The range at elastic limit was the smallest in the group of Hi-T, .018'$\;\times\;$.025', 15mm loop length, open loop, non-gable, and the largest in the group of HI-T, .016'$\;\times\;$.022', 20mm loop length, closed loop, gable. 4. Loop configuration and loop length were the most effective factors on the elastic properties of looped wires, and gabling was the least effective.

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MECHANICAL ANALYSIS OF THE PATTERN OF MOVEMENT DURING RETRACT10N OF MAXILLARY INCISORS BY SPACE CLOSING LOOP (Space closing loop에 의해 야기되는 상악 절치부 이동양상에 관한 역학적 연구)

  • Min, Sang-Hong;Yoon, Young-Jooh;Kim, Kwang-Won
    • The korean journal of orthodontics
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    • v.25 no.2
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    • pp.143-152
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    • 1995
  • This study was performed, by Finite Element Method, to evaluate the stress distribution on the periodontal tissue according to activation of the various closing loops and to predict the pattern of movement of maxillary incisors. At the same time, bull loop, key-hole loop, T-loop, combination loop and asymmetrical T-loop which were used for retraction of maxillary incisors was analysed by Finite Element Method. The following results were obtained 1. Horizontal force was the greatest in bull loop, the followed by key-hole loop, combination loop, T-loop and initial tooth movement exhibited uncontrolled tipping. 2. Horizontal force in asymmetrical T-loop compared to other closing loops was remarkably decreased, and the intrusive force on the incisors occurred. 3. As torque was increased, the moment was increased as a linear increment. 4. As moment was increased, initial movement of tooth changed to root movement from uncontrolled tipping.

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Design of Combined GPS Signal Tracking Loop based on Kalman Filter (칼만필터 기반의 통합 GPS 수신기 추적루프 설계)

  • Song, Jong-Hwa;Jee, Gyu-In;Kim, Kwang-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.9
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    • pp.939-947
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    • 2008
  • The GPS tracking loop consists of three parts in general: discriminator, loop filter and DCO (Digitally Controlled Oscillator). The loop filter is the main part of the tracking loop designed to ensure a good tracking performance. Generally, the loop filter is designed using classical PI(Proportional Integral) control. Although the carrier Doppler and code Doppler are generated by the same relative movement between the satellite and the user, often, the loop filters for each tracking loop are designed separately and independently. Sometimes, they are used in a combined manner such as carrier aided code tracking, FLL assisted PLL, etc. For better GPS signal tracking, we need to design the FLL/PLL/DLL altogether optimally. The purpose of this paper is to design a GPS receiver tracking loop based on the Kalman filter in a combined manner. Also, the proposed GPS receiver tracking loop is compared with a conventional tracking loop in terms of the transfer function and the DCO input. This paper shows that conventional tracking loop is equal to the Kalman filter based tracking loop.

A Loop Transformation for Parallelism from Single Loops

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • v.2 no.4
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    • pp.8-11
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    • 2006
  • This paper describes several loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

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Loop-loop EM inversion and its applicability to subsurface exploration

  • Sasaki, Yutaka
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.3-6
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    • 2006
  • There are three types of frequency-domain loop-loop EM induction method, depending on the loop separation and their location relative to the ground surface: horizontal-loop EM (HLEM), fixed small-loop EM, and helicopter-borne EM (HEM) methods. Multidimensional inversion provides tomographic images of the subsurface resistivity structure and thus enhances the interpretational accuracy of loop-loop EM data. HLEM method is shown to be effective for exploring groundwater resources in weathered and fractured crystalline basement terrains in semi-arid regions. Also, HEM method is useful for locating weak zones in landslide areas. The applicability of inversion to small-loop EM data depends solely on the S/N ratio. The quadrature response of small-loop EM data can only give the equivalent conductivity of a homogenous half-space model, and thus the in-phase component is essential in inverting EM data. However, the in-phase response is much lower and decreases more rapidly with decreasing frequency than the quadrature response. Further work is needed to obtain conductivity-depth images from small-loop EM data.

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Carrier Recovery Loop for PSK Signal (PSK 신호를 위한 새로운 디지털 Carrier Recovery Loop에 관한 연구)

  • 송재철;최형진
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.11
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    • pp.1-10
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    • 1993
  • A Study on New Digital In this paper, we propose a new Angular Form Carrier Recovery Loop(AFCR loop) for PSK modulation technique. AF CR loop includes detected angle symbol and Multi Level Hardlimiter. Using zero crossing DPLL, we model 1st 2nd AF CR loop, and also derive SCurve. In order to prove steady state operation of AF CR loop, we evaluate performance of this loop by Monte-Carlo and analytical simulation method. We also compare the performance of AF CR loop to that of other loop in terms of acquisition, S-Curve, and RMS jitter. From the comparison result, we verify that the performance of AF CR loop operates well in steady state.

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A Continuous Fine-Tuning Phase Locked Loop with Additional Negative Feedback Loop (추가적인 부궤환 루프를 가지는 연속 미세 조절 위상 고정루프)

  • Choi, Young-Shig
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.4
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    • pp.811-818
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    • 2016
  • A continuous fine-tuning phase locked loop with an additional negative feedback loop has been proposed. When the phase locked loop is out-of-lock, the phase locked loop has a fast locking characteristic using the continuous band-selection loop. When the phase locked loop is near in-lock, the bandwidth is narrowed with the fine loop. The additional negative feedback loop consists of a voltage controlled oscillator, a frequency voltage converter and its internal loop filter. It serves a negative feedback function to the main phase locked loop, and improves the phase noise characteristics and the stability of the proposed phase locked loop. The additional negative feedback loop makes the continuous fine-tuning loop work stably without any voltage fluctuation in the loop filter. Measurement results of the fabricated phase locked loop in $0.18{\mu}m$ CMOS process show that the phase noise is -109.6dBc/Hz at 2MHz offset from 742.8MHz carrier frequency.

The Decision of the Optimal Shape of Inductive Loop for Real-Time Traffic Signal Control (실시간 교통신호제어를 위한 루프 검지기의 최적형태결정에 관한 연구)

  • 오영태;이철기
    • Journal of Korean Society of Transportation
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    • v.13 no.3
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    • pp.67-86
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    • 1995
  • It requires the detector system which can collect highly reliable traffic data in order to perform the real-time traffic signal control. This study is to decide the optimal shape of inductive loop for the real-time traffic signal control .This loop is located at the stopline in the signalized intersection for DS(Degree of Saturation) control. In order to find out the optimal shape of loop, 6types of experiments were performed . The results of the basic experiments of loops are as follows ; -the optimal number of turns for loop is 3 turns. -the impedance values of the loop detectors are similar to that of NEMA standards -the 1.8${\times}$4.5M loop is excellent for sensitivity in actual detection range of car length comparing to other shape of inductive loops. At the experimental of establishments of the optimal loop shape, it found that 1.8 4.5M loop has the highest values of $\DeltaL$ comparing to other types of loops, It means that the range of Lead-in cable length of this loop. And this loop is highly reliable in occpupancy time. Conclusivley, the 1.8${\times}$4.5M inductive loop is the optimal solution as a stop line loop detector for real -time traffic signal control.

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Performance Evaluation of Joint Blind Equalizer and Carrier Recovery for QAM Signal (QAM 신호를 위한 Blind 등화기 Carrier Recovery 결합에 관한 성능평가)

  • 송재철;최형진
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.11
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    • pp.2067-2080
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    • 1994
  • Recently, joint blind equalization and carrier recovery for digital mobile transmission system is of growing interest. In this paper, we describe new receiver structure of joint godard blind equalizer and various recovery loop for QAM modulated signal. After a brief review of Godard blind equalizer and MAP estimation Costas loop, Generalized Costas loop, Leclert loop, Angular form loop, we present two kinds of receiver structures for joint blind equalization and carrier recovery. Using a Monto Carlo simulation technique, we can confirm that two kinds of receiver structures operate very well in the steady state.

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All-optical gain control in erbium-doped fiber amplifier using a fiber grating (광섬유격자를 이용한 Erbium 첨가 광섬유 증폭기의 광학적 이득제어)

  • 박희갑
    • Korean Journal of Optics and Photonics
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    • v.8 no.1
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    • pp.58-62
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    • 1997
  • A new, simple lasing loop configuration employing a fiber grating was proposed and demonstrated for all-optical gain control of erbium-doped fiber amplifier. The lasing loop was designed such that the fiber grating acts as a notch filter to cutoff the lasing light as well as selects the lasing wavelength. The operating gain was clamped to the same level as the loop loss and it could be varied with a tunable directional coupler in the loop. It is believed that this type of gain-controlled erbiumdoped fiber amplifier can have several advantages when used in wavelength-division-multiplexed transmission systems.

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