• Title/Summary/Keyword: Set-up compensation

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Inverter Output Voltage Synthesis Using Novel Dead Time Compensation (새로운 데드타임보상법을 이용한 인버터 출력전압의 합성)

  • 최종우;설승기
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.4
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    • pp.453-459
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    • 1995
  • In this paper, a novel dead time compensation method is presented which produces inverter output voltages equal to reference voltages. An experimental result is also presented to demonstrate the validity of the proposed method. It shows that the compensation of the dead time is possible up to a sub-microsecond range. And the reference voltage can be used as a feedback value, which is essential for sensorless vector control and flux estimation. The method is based on space vector PWM strategy and can be carried out automatically by an inverter controller for initial set-up without any extra hardware.

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Inverter Output Voltage Synthesis Using Novel Dead Time Compensation (새로운 데드타임보상법을 이용한 인버터 출력전압의 합성)

  • Choi, Jong-Woo;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.262-264
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    • 1994
  • In is paper, a novel dead time compensation method is presented which produces inverter output voltages equal to reference voltages. An experimental result is also presented to demonstrate the validity of the proposed method. The reference voltage can be used as a feedback value, which is essential for sensorless vector control and flux estimation. The method can be carried out automatically by an inverter controller for initial set-up without any extra hardware.

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The Compensation of Machine Vision Image Distortion

  • Chung, Yi-Chan;Hsu, Yau-Wen;Lin, Yu-Tang;Tsai, Chih-Hung
    • International Journal of Quality Innovation
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    • v.5 no.1
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    • pp.68-84
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    • 2004
  • The measured values of a same object should remain constant regardless of the object's position in the image. In other words, its measured values should not vary as its position in the image changes. However, lens' image distortion, heterogeneous light source, varied angle between the measuring apparatus and the object, and different surroundings where the testing is set up will all cause variation in the measurement of the object when the object's position in the image changes. This research attempts to compensate the machine vision image distortion caused by the object's position in the image by developing the compensation table. The compensation is accomplished by facilitating users to obtain the correcting object and serves the objective of improving the precision of measurement.

A Cost-aware Scheduling for Reservation-Based Long Running Transactions (예약기반 장기수행 변동처리를위한 비용인지 시간계획)

  • Lin, Qing;Pham, Phuoc Hung;Byun, Jeong Yong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.11a
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    • pp.1248-1251
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    • 2011
  • Web Service technologies make the automation of business activities that are distributed across multiple enterprises possible. Existing extended transaction protocols typically resort to compensation actions to regain atomicity and consistency. A reservation-based transaction protocol is proposed to reduce high compensation risk. However, for a serial long running transaction processing, the resource that is reserved in the early stage may be released due to resource holding time expires. Therefore, our analysis theoretically illustrates a scheduling scheme that tries to prevent the loss of resource holding as well as gain an optimized execution plan with minimum compensation cost. In order to estimate cost of different schedules, we set up a costing model and cost metric to quantize compensation risk.

The Impact of the Land Compensation Act to the Outcome of Land Compensation: a Case Study of Gyeongsan DAEIM Public Housing District (경산 대임공공주택지구의 대토보상결과를 통해 살펴본 대토보상제도 문제점과 개선방안 연구)

  • Park, Chang-Yul;Park, Jung-Jun;Son, Sun-Gum
    • Land and Housing Review
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    • v.11 no.4
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    • pp.75-92
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    • 2020
  • This study explores the outcome of the current Land Compensation Act for the indigenous residents of DAEIM Public Development Project Zone in Gyeongsan City. The purpose of the law is to return part of the development gains to the native residents and to support the re-settlement of the native residents. As the Land Compensation Act applies to each area with different standards, the monetary terms of land compensation which the native residents eventually receive varies across the region and development sites. That means the development gain is not fairly shared with the native residents of the redevelopment area and it does not necessarily support the settlement of the existing residents. It is supposed that the actual compensation for the native residents should be in full cash value but it is not in reality. The study demonstrates the outcomes of the land compensation that the residents received are far from the original purpose of the Compensation Act using the case example of DAEIM Public Development Zone in Gyeongsan, Gyeongsangbukdo. Only a small proportion of the natives managed to achieve the development gains. Accordingly the majority of the native residents has lost re-settlement opportunity. It suggests that the Compensation Act and the implementation procedure should be reviewed and revised accordingly. The details of compensation plan should be tested and set up in line with the characteristics of the project area. In particular, the compensation details in terms of the size and types of land, average value of land for indigenous residents receive, and the amount of compensation per household should be clearly demonstrated to the resident.

A Study on the Charactistics of Machined Surface due to Cutter Runout (커터 런 아웃과 가공표면 생성에 관한 연구)

  • Hwang, J.;Lee, K. Y.;Shin, S. C.;Chung, E. S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.873-877
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    • 1997
  • This paper presents experimental results to know the charcteristics of machined surface due to cutter runout. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear, amplification of force variation and hence enargement vibration amplitude. To develop in-proess cutter runout compensation system, set-up the micro-positoning mechanism which is based on piezoelectric translator embeded in the work holder to manipulate the depth of cut in real-time. And feasibility test of system was done under the various experimental cutting conditions. This results provide lots of information to build-up the precision machining technology.

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Development of Simple Simulation by Changing the Stroke of Cylinder for a Oscillation (모의실험장치에서의 기계적인 동요에 대한 단순모사 장치개발)

  • Seol, Sang-Seok;Chung, Won-Jee;Jung, Dong-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.2
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    • pp.89-94
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    • 2016
  • Equipments to influence by external force have to take effect mechanical oscillation. These equipments regardless of the movement on the external force such as roll, pitch and heave etc, worked to keep the height of tote are required for activeness and needed a device as equipment's fluctuation for rapidly compensation. Because the actual development of these devices is difficult to cost-effectively, we were developed to compensation simulator scaled down 1/50. In this paper, we were studying kinematic characteristics, designed the simulator to grasp the point and manufactured. This paper was analyzed for confirming the superiority of compensation simulator and set up 50 ton crane in practice.

Precision Stabilization Control of Servo-system by Using Friction Compensation (마찰보상을 통한 서어보제어계의 정밀 안정화 제어)

  • Kang, Min-Sig
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.3 s.96
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    • pp.109-115
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    • 1999
  • This paper presents a stabilization control designed to improve position stabilization performance of a position servo-system(turret) mounted on a manuvering platform(vehicle). In the consideration of the motion of the platform, a dynamic model of the stabilization system is derived and shows the viscous and stick-slip friction torques are the major source of stabilization errors. An extended generalized minimum variance control which consists of a feedforward disturbance compensation as well as a pole placement feedback control is suggested to reduce the stabilization errors caused from the friction disturbances. This modeling and control are applied to a small experimental set-up and the experimental results confirm the accuracy of the model and the effectiveness of the suggested control.

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Hardware temperature compensation technique for hot-wire anemometer by using photoconductive cell (광도전성저항을 이용한 열선유속계의 하드웨어적 온도보상에 관한 연구)

  • Lee, Sin-Pyo;Go, Sang-Geun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.11
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    • pp.3666-3675
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    • 1996
  • A new hardware temperature compensation method for hot-wire anemometer is investigated and an analog compensating circuit is proposed in this article. A photoconductive cell is introduced here as a variable resistor in the anemometer bridge and the linearized output of a thermistor is used to monitor the input of the photoconductive cell. In contrast with the conventional method, any type of temperature sensor can be used for compensation if once the output of thermometer varies linearly with temperature. So the present technique can diversify the compensating means from a conventional passive compensating resistance to currently available thermometers. Because the resistance of a photoconductive cell can be set precisely by adopting a stabilizing circuit whose operation is based on the integration function of the operational amplifier, the accuracy of compensation can be enhanced. As an example of linearized thermometer, thermistor sensor whose output is linearized by a series resistor was used to monitor the fluid temperature variation. Validation experiment is conducted in the temperature ranged from 30 deg. C to 60 deg. C and the velocity up to 40 m/s. It is found that the present technique can be adopted as a compensating circuit for anemometer and hot-wire type airflow meter.