• Title/Summary/Keyword: Dynamic Measuring

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A Congestion Control Mechanism for Supporting Differentiated Service in Mobile Ad hoc Networks

  • Kim Jin-Nyun;Ha Nam-Koo;Cho Dong-Hoon;Kim Hyun-Sook;Han Ki-Jun
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.143-146
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    • 2004
  • Differentiated services (DiffServ) has been widely accepted as the service model to adopt for providing quality-of­service (QoS) over the next-generation IP networks. There is a growing need to support QoS in mobile ad hoc networks. Supporting DiffServ in mobile ad hoc networks, however, is very difficult because of the dynamic nature of mobile ad hoc networks, which causes network congestion. The network congestion induces long transfer packet delay and low throughput which make it very difficult to support QoS in mobile ad hoc networks. We propose DiffServ module to support differentiated service in mobile ad hoc networks through congestion control. Our DiffServ module uses the periodical rate control for real time traffic and also uses the best effort bandwidth concession when network congestion occurs. Network congestion is detected by measuring the packet transfer delay or bandwidth threshold of real time traffic. We evaluate our mechanism via a simulation study. Simulation results show our mechanism may offer a low and stable delay and a stable throughput for real time traffic in mobile ad hoc networks.

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The Characteristics of Transient Response According to Lasing Wavelengths and Propagation Directions in Double-Pass Gain-Clamped L-band EDFA with Linear Cavity (이중경로증폭 선형공진 고정이득 L-band EDFA에서 발진 파장 및 방향에 따른 과도응답 특성)

  • Kim Ik-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6A
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    • pp.547-555
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    • 2006
  • We implemented DPU(Double-Pass Gain-Clamped) L-band EDFA for highly efficient amplification. A lasing signal generated within the linear cavity, can minimize the fluctuation of surviving channels when several WDM(Wavelength Division Multiplexing) channels are added or dropped. The new method measuring the characteristics of transient response of surviving channels quantitatively is suggested. It is to measure the ratio of lasing output before add or drop to that after add or drop. We investigated dynamic characteristics by using this method according to lasing wavelengths and propagation directions within the cavity. Experimental measurements show that the short lasing wavelength and backward propagation direction is the best condition for small fluctuation of surviving channels.

Mixing Efficiency Evaluation in Y-channel Micromixer Using LIF Confocal Microscope (LIF 공초점 현미경을 이용한 Y-채널 마이크로믹서의 혼합 효율 평가)

  • Kim, Kyoung-Mok;Shin, Yong-Su;Ahn, Yoo-Min;Lee, Do-Hyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.2 s.257
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    • pp.159-166
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    • 2007
  • Mixing between two or more reagents is one of important processes in biochemical microfluidics. In efficient micromixer design, it is essential to analyze flow pattern and evaluate mixing efficiency with good precision. In this work, mixing efficiency for Y-channel micromixer is measured by fluorescence intensity using LIF(Laser Induced Fluorescence) Confocal Microscope. The Y-channel micromixers are fabricated with polydimethylsiloxane(PDMS) and those are bonded to glass plate through Plasma bonding. Nile Blue A is injected into the micromixer as a fluorescence dye for measuring of fluorescence intensity by He/Ne laser. For visualization of the flow pattern, dynamic image capturing is carried out using CAM scope. For the comparison with computer simulation, modified SIMPLE algorithm for incompressible flow equation is solved for the same geometry as in the experiment. Throughout the experiments and computer simulation, accurate mixing efficiency evaluation process for a PDMS Y-channel micromixer is established.

The Effects of Two Types of Trunk Stability Exercise on the Gait Factors of Stroke Patients

  • Kim, Ji Sung
    • Journal of International Academy of Physical Therapy Research
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    • v.8 no.2
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    • pp.1128-1134
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    • 2017
  • The purpose of this study is to identify the effects of two trunk stability exercise types on the gait factors of stroke patients. We randomly divided 24 old elderly patients with hemiplegia, who were hospitalized due to stroke, into a two groups, each with its own six-week exercise program: one that used of a dynamic trunk stability exercise using with physio-balls(n=12) and a group of one that used a static trunk stability exercise using on mats(n=12). After measuring the participants gait ability a sin a pre-test, we again measured their ability again as in a posttest after two-for both types of six-week exercise programs for each group. The analysis of the data analysis showed that both ball and mat exercise programs significantly improved the participants' gait velocity and stride length; cadence, however, was significantly changed only by the ball exercise program. In conclusion, both types of trunk stability exercise may be useful in improving the gait ability of stroke patients, and, in particular, the former can be used as an exercise method that effectively significantly affects more various other gait factors.

Design of Communication System for Intelligent Multi Agent Robot System (지능형 멀티 에이전트 로봇시스템을 위한 통신시스템의 설계)

  • Kim, Jun-Yeup;Park, Seung-Min;Ko, Kwang-Eun;Jang, In-Hun;Sim, Kwee-Bo
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.8
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    • pp.758-767
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    • 2012
  • In the ad-hoc wireless network environment, that the fixed sensor nodes and the sensor nodes to move are mixed, as the number of the sensor nodes with mobility are getting more, the costs to recover and maintain the whole network will increase more and more. This paper proposed the CDSR (Cost based Dynamic Source Routing) algorithm being motivated from the typical DSR algorithm, that is one of the reactive routing protocol. The cost function is defined through measuring the cost which any sensor node pays to participate in the whole network for communication. It is also showed in this paper that the proposed routing algorithm will increase the efficiency and life of whole sensor network through a series of experiments.

A Study on Modelling and Attitude Control Techniques of LEO Satellite (저궤도 위성체의 모델링 및 자세제어 기법에 관한 연구)

  • Lho, Young-Hwan
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.6
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    • pp.9-13
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    • 2009
  • In the three axis control of Low Earth Orbit (LEO) satellite by using reaction wheel and gyro, a reaction wheel produces the control torque by the wheel speed or momentum, and a gyro carries out measuring of the attitude angle and the attitude angular velocity. In this paper, the dynamic modelling of LEO is consisted of the one from the rotational motion of the satellite with basic rigid body model and a flexible model, in addition to the reaction wheel model. A robust controller $(H_\infty)$ is designed to stabilize the rigid body and the flexible body of satellite, which can be perturbed due to disturbance, etc. The result obtained by $H_\infty$ controller is compared with that of the PI (Proportional and Integration) controller, which has been traditionally using for the stabilizing LEO satellite.

Measuring Knowledge Management performance of the construction organization (건설조직의 지식경영 성과측정)

  • Kwon, Soon-Seok;Park, Moon-Seo;Lee, Hyun-Soo;Ahn, Chang-Bum
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.868-871
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    • 2007
  • The current economy is summarized by increasing business competitiveness and leaner organizations, and the risk and uncertainties inherent in such dynamic environments have increased the importance of managing organizational knowledge. Like the preceding, the construction industry is required to make an effort for survival and takeoff, and most construction companies recognize that knowledge management improves efficiency and effectiveness and the necessity on the innovation of business itself and it is the current of the times. But at this point in time, companies have doubts about performance following the introduction of KM, and set to show interest in developing a measurement method. So, This study analyzes the existing model for performance measurement and based on results derived, presents the method for performance measurement.

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Design of a Rule-Based Solution Based on MFC for Inspection of the Hybrid Electronic Circuit Board (MFC 기반 하이브리드 전자보오드 검사를 위한 규칙기반 솔루션 설계)

  • Ko Yun-Seok
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.9
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    • pp.531-538
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    • 2005
  • This paper proposes an expert system which is able to enhance the accuracy and productivity by determining the test strategy based on heuristic rules for test of the hybrid electronic circuit board producted massively in production line. The test heuristic rules are obtained from test system designer, test experts and experimental results. The guarding method separating the tested device with circumference circuit of the device is adopted to enhance the accuracy of measurements in the test of analog devices. This guarding method can reduce the error occurring due to the voltage drop in both the signal input line and the measuring line by utilizing heuristic rules considering the device impedance and the parallel impedance. Also, PSA(Parallel Signature Analysis) technique Is applied for test of the digital devices and circuits. In the PSA technique, the real-time test of the high integrated device is possible by minimizing the test time forcing n bit output stream from the tested device to LFSR continuously. It is implemented in Visual C++ computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the interface with the electronic circuit database and the hardware direct control. Finally, the effectiveness of the builded expert system is proved by simulating the several faults occurring in the mounting process the electronic devices to the surface of PCB for a typical hybrid electronic board and by identifying the results.

The Study on the Simple Measurement by Using the Strain Gauge at Dam Dynamic Behavior Analysis (댐 거동 분석에서의 Strain Gauge를 이용한 단일 계측에 관한 연구)

  • Lee, Seungho
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.1
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    • pp.5-11
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    • 2007
  • Internal stress variation in the face slab concrete induced by reservoir water pressure may affect on the stability of the dam so that the reclamation type of strain gauge is applied for measuring internal stress variation. In this study, internal as well as external stress variation of dam was measured by using strain gauge that was reclaimed to the ${\circ}{\circ}$ dam. In the result, it was confirmed that other measurements by relevant gauges need to be supplemented as the use of strain gauge only is insufficient to evaluate the stability analysis and global behavior of the dam.

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The transceiver design for telemedicine using DSP (DSP를 이용한 원격 진료용 송수신 단말기 설계)

  • 이종회;이주원;조원래;한석붕;이건기
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.1
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    • pp.97-104
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    • 1999
  • In this study we show a telemedicine system using a DSP, which gives fast and exact medical data such as the ECG signal of the external emergency patient and enables the patient to get temporary treatments under the direction of a doctor in the hospital. This transceiver, which is able to treat the real time transmission of dynamic medical data captured by the measuring instrument and bidirectional communication of voice signal, is implemented using DSB-SC as modulation and demodulation technique and digital filter of each terminal are implemented as FIR filter. The system designed with DSP in this study is very small and compact and it can k, furthermore, to support additional biomedical signals just by renewing the software.

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