• Title/Summary/Keyword: testing and calibration

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Adaptive Compensation Control of Vehicle Automatic Transmissions for Smooth Shift Transients Based on Intelligent Supervisor

  • Kim, Deok-Ho;Han, Jin-O;Sin, Byeong-Gwan;Lee, Gyu-Il
    • Journal of Mechanical Science and Technology
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    • v.15 no.11
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    • pp.1472-1481
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    • 2001
  • In this paper, an advanced shift controller that supervises the shift transients with adaptive compensation is presented. Modern shift control systems for vehicle automatic transmission are designe d to provide smooth transients for passengers' comfort and better component durability. In the conventional methods, lots of testing and calibration works have been done to tune gains of the controller, but it does not assure optimum shift quality at all times owing to system variations often caused by uncertainties in shifting hydraulic systems and external disturbances. In the proposed control scheme, an adaptive compensation controller with intelligent supervisor is implemented to achieve improved shift quality over the system variations. The control input pattern which generates clutch pressure commands in hydraulic actuating systems, is updated through a learning process to adjust for each subsequent shift based on continuous monitoring of shifting performance and environmental changes. The proposed algorithm is implemented and evaluated on the experimental test setup. Results from the experimental studies for several operation modes show both improved performance and adaptability of the proposed shift controller to uncertain changes of the shifting environment in vehicle power transmission systems.

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  • Lee, D.H.;Nam, U.W.;Kim, G.H.;Pak, S.;Zemcov, M.;Bock, J.J.;Battle, J.;Sullivan, I.;Mason, P.;Tsumura, K.;Matsumoto, T.;Matsuura, S.;Renbarger, T.;Keating, B.
    • Publications of The Korean Astronomical Society
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    • v.22 no.4
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    • pp.169-175
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    • 2007
  • The international cooperation project CIBER (Cosmic Infrared Background ExpeRiment) is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. Currently, all the subsystems have been built, and the integration, testing, and calibration of the CIBER system are on process for the scheduled launch in June 2008.

Study for confidence security of certification of management system and validity examination (경영시스템 인증의 신뢰성 확보 및 유효성 심사에 관한 연구 -ISO 9001 인증을 중심으로-)

  • Lee, Eun-Sook;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.11 no.2
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    • pp.127-135
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    • 2009
  • In today's society it is often required to state objectively conformity of products (including services) to specified requirements. Conformity assessment bodies (CABs). can objectively state such conformity. These CABs perform conformity assessment activities that include certification, inspection, testing and calibration. A system to accredit CABs conformity assessment services should provide confidence to the purchaser and regulator. Certification of management system is one of means of providing assurance that the organization has implemented a system for the management of the relevant aspects of its activities, in line its policy.

Development and deployment of large scale wireless sensor network on a long-span bridge

  • Pakzad, Shamim N.
    • Smart Structures and Systems
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    • v.6 no.5_6
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    • pp.525-543
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    • 2010
  • Testing and validation processes are critical tasks in developing a new hardware platform based on a new technology. This paper describes a series of experiments to evaluate the performance of a newly developed MEMS-based wireless sensor node as part of a wireless sensor network (WSN). The sensor node consists of a sensor board with four accelerometers, a thermometer and filtering and digitization units, and a MICAz mote for control, local computation and communication. The experiments include calibration and linearity tests for all sensor channels on the sensor boards, dynamic range tests to evaluate their performance when subjected to varying excitation, noise characteristic tests to quantify the noise floor of the sensor board, and temperature tests to study the behavior of the sensors under changing temperature profiles. The paper also describes a large-scale deployment of the WSN on a long-span suspension bridge, which lasted over three months and continuously collected ambient vibration and temperature data on the bridge. Statistical modal properties of a bridge tower are presented and compared with similar estimates from a previous deployment of sensors on the bridge and finite element models.

Reference X-ray Irradiation System for Personal Dosimeter Testing and Calibration of Radiation Detector

  • Lee, Seung Kyu;Chang, Insu;Kim, Sang In;Lee, Jungil;Kim, Hyoungtaek;Kim, Jang-Lyul;Kim, Min Chae
    • Journal of Radiation Protection and Research
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    • v.44 no.2
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    • pp.72-78
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    • 2019
  • Background: In the calibration and testing laboratory of Korea Atomic Energy Research Institute, the old X-ray generator used for the production of reference X-ray fields was replaced with a new one. For this newly installed X-ray irradiation system, beam alignment as well as the verification of beam qualities was conducted. Materials and Methods: The existing X-ray generator, Phillips MG325, was replaced with YXLON Y.TU 320-D03 in order to generate reference X-ray fields. Theoretical calculations and Monte Carlo simulations were used to determine initial filter thickness. Beam alignment was performed in three steps to deliver a homogeneous radiation dosage to the target at different distances. Finally, the half-value layers were measured for different X-ray fields to verify beam qualities by using an ion chamber. Results and Discussion: Beam alignment was performed in three steps, and collimators and other components were arranged to maintain the uniformity of the mean air kerma rate within ${\pm}2.5%$ at the effective beam diameter of 28 cm. The beam quality was verified by using half-value layer measurement methods specified by American National Standard Institute (ANSI) N13.11-2009 and International Organization for Standardization (ISO)-4037. For each of the nine beams than can be generated by the new X-ray irradiation system, air kerma rates for X-ray fields of different beam qualifies were measured. The results showed that each air kerma rate and homogeneity coefficient of the first and second half-value layers were within ${\pm}5%$ of the recommended values in the standard documents. Conclusion: The results showed that the new X-ray irradiation system provides beam qualities that are as high as moderate beam qualities offered by National Institute of Standards and Technology in ANSI N13.11-2009 and those for narrow-spectrum series of ISO-4037.