• Title/Summary/Keyword: physical function tests

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Thermal Shock Tests and Thermal Shock Parameters for Ceramics

  • Awaji, Hideo;Choi, Seong-Min
    • Journal of the Korean Ceramic Society
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    • v.49 no.4
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    • pp.385-396
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    • 2012
  • Thermal shock test methods and thermal shock parameters for ceramics were reviewed from the following viewpoints: (1) The test methods should be based on the precise estimation of both temperature and thermal stress distributions in a specimen taking into account the temperature-dependent thermo-mechanical properties; (2) The thermal shock parameters must be defined as a physical property of the materials and described as a function of temperature at the fracture point of the specimen; (3) The relation between the strength and fracture toughness of brittle ceramics under a thermal shock load must be the same as the relation under a mechanical load. In addition, appropriate thermal shock parameters should be defined by the thermal shock strength and thermal shock fracture toughness based on stress and energy criteria, respectively. A constant heat flux method is introduced as a testing technique suitable for estimating these thermal shock parameters directly from the electric power charged.

Service Quality Characteristics and Performance In a University Hospital

  • Lee, Byoung-Chan;Lee, Chang W.
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2001.01a
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    • pp.373-377
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    • 2001
  • This study is to examine the factors that influence the performances of service quality in university hospitals by investigating systematically the condition of service quality. A synthesis of the health care quality is conducted to identify physical quality, operating process quality, and human resources quality that relate to both the overall satisfaction and intention of revisit. Based on the proposed hypotheses, the relationships between the service quality factors and performance are examined using data collected from 167 patients in three hospitals, Korea. Reliability and validity tests are performed for examining its relationship with service quality in health care systems. Total eight independent variables with respect to three service quality levels and two dependent variables for performance are identified for relationships between service quality and performance in health care systems. The results provide health care managers with a managerial insight to the planning function of performance with service quality in health care systems as well as other operations (business, government, or other service organizations) systems. Implication of the study for theory, future studies, and practices are discussed.

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Characteristics and Useful Life Prediction of Rubber Spring for Railway Vehicle (전동차용 방진고무스프링 특성 및 사용수명 예측)

  • Woo, Chang-Su;Park, Hyun-Sung;Park, Dong-Chul
    • Journal of the Korean Society for Railway
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    • v.10 no.2 s.39
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    • pp.211-216
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    • 2007
  • Rubber components are widely used in many application such as vibration isolators, damping, ride quality. Rubber spring is used in primary suspension system for railway vehicle. Characteristics and useful life prediction of rubber spring was very important in design procedure to assure the safety and reliability. Non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by physical tests which are uniaxial tension, equi-biaxial tension and pure shear test. The computer simulation was executed to predict and evaluate the load capacity and stiffness for rubber spring. In order to investigate the useful life, the acceleration test were carried out. Acceleration test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the acceleration test, several useful life prediction for rubber spring were proposed.

Study of the Functional Test and Quality Assurance Procedure of High Performance Aircraft Control Surfaces Integrate Servo Actuator (고성능 통합 비행 조정면 구동 장치의 성능 시험 및 품질보증 절차 수립에 관한 연구)

  • Jo, Jang-Hyen
    • Journal of the Korean Society of Industry Convergence
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    • v.3 no.3
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    • pp.251-256
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    • 2000
  • This report analyzes the Source Qualification Test which is composed of main functional and environmental tests for the localizing avionics(electronic subsystem for aircrafts and spacecraft) and high performance mechanical subsystem. Especially the detail test approaches of integrated servo actuators which is the main part to supply the power to the main and other flying control panel. Nowadays this subsystem works with mechanical and electrical engineering technique. In detail, electrical signal is used as input and transferring tool and mechanical part is the output as a power and manufacture the physical dimensions and functions. Finally in this review, the new test procedure to prove the function by the new manufacturer is established.

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NIIRS ESTIMATION USING THE GENERAL IMAGE-QUALITY EQUATION FOR MONITORING IMAGE DEGRADATION

  • Kim, Dong-Wook;Kim, Tae-Jung;Kim, Hee-Seob
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.53-56
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    • 2008
  • Generally, the quality of satellite images is expressed by GSD (Ground Sample Distance), MTF (Modulation Transfer Function) and SNR (Signal to Noise Ratio). However, these factors are technology-oriented and do not explain interpretability of satellite images. We need a standardized index which shows standard of interpretability. In this study, we estimated NIIRS (National Imagery Interpretability Rating Scale) through the GIQE (General Image Quality Equation) which is able to judge image interpretability with the standardized index. Traditionally, NIIRS has been determined manually by specialized image analysts. We used the GIQE in order to reduce inefficiency and high costs cause by manual interpretation and to produce accurate NIIRS. For monitoring image degradation, we estimated GIQE physical parameters from image analysis and carried out time series analysis about the quality of the KOMPSAT-1 images. On all of the tests, we were able to identify the image degradation due to the changing time. This indicates that NIIRS derived from GIQE will be used for image degradation indicator.

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Ballistic behavior of steel sheet subjected to impact and perforation

  • Jankowiak, Tomasz;Rusinek, Alexis;Kpenyigba, K.M.;Pesci, Raphael
    • Steel and Composite Structures
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    • v.16 no.6
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    • pp.595-609
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    • 2014
  • The paper is reporting some comparisons between experimental and numerical results in terms of failure mode, failure time and ballistic properties of mild steel sheet. Several projectile shapes have been considered to take into account the stress triaxiality effect on the failure mode during impact, penetration and perforation. The initial and residual velocities as well as the failure time have been measured during the tests to estimate more physical quantities. It has to be noticed that the failure time was defined using a High Speed Camera (HSC). Thanks to it, the impact forces (average and maximum level), were analyzed using numerical simulations together with an analytical description coupled to experimental observations. The key point of the model is the consideration of a shape function to define the pulse loading during perforation.

Use of selegiline in 3 Cases of Canine Pituitary-dependent Hyperadrenocorticism (개의 뇌하수체 의존성 부신 피질 기능 항진증에서의 selegiline 적용)

  • 김주민;황철용;윤정희;윤화영;한홍율
    • Journal of Veterinary Clinics
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    • v.19 no.4
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    • pp.455-460
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    • 2002
  • Pituitary-dependent hyperadrenocorticism (PDH) was diagnosed with history taking, physical examination, complete blood count, serum chemistry profiles, abdominal radiology, ultrasonography and adrenal function tests in 3 dogs. Their clinical signs were polyuria, polydipsia, polyphagia, bilateral symmetrical truncal alopecia and secondary infection in skin or urinary tract. Especially one dog showed severe clinical signs such as calcinosis cutis and delayed wound healing. These 3 dogs were diagnosed as PDH, and treated with selegiline 1-2 mg/kg /ay sid PO. 2 dogs with clinical signs of PDH were disappeared and improved, but 1 dog with severe illness progressed gradually despite of selegiline and mitotane application, and eventually died.

Physical Properties of Excavated Rocks in Taegu Area (대구지역 굴착암석의 물리적 특성)

  • 이상호;차완용;김영수;이재호
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.265-270
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    • 1999
  • At this study, we investigated the chemical component and the mineral granular composition of sedimentary rock and others where were distributed in Taegu area and compared correlations with each data through the various physicla and mechanical characteristic test. As the result, d and E, they are kinds of granite, which contain much albite than others were proved to be strong by mechanical tests and the correlation moduli were proved to be more than 0.8 except P wave velocity-Poisson's ration relation when examined Elastic moduluous -Poisson's ration, P, wave velocity-Uniaxial compression strength, Elastic modulous -Uniaxial compression strength and Uniaxial compression strength-Poisson's ration correlation function graph.

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Small-Fiber Neuropathy (세섬유 신경병증)

  • Lee, Dong Kuck
    • Annals of Clinical Neurophysiology
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    • v.5 no.1
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    • pp.1-10
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    • 2003
  • Small-fiber neuropathy (SFN) is a common clinical problems. The disorder is a generalized peripheral polyneuropathy that selectively involves small-diameter myelinated and unmyelinated nerve fibers. It is often idiopathic and typically presents with painful feet in patients over the age of 60. And autoimmune mechanisms are often suspected, but rarely identified. The clinical features consisted of painful dysesthesias and postganglionic sympathetic dysfunction, as well as reduced pinprick and temperature sensation. Although affected patients complain of neuropathic pain, this condition is often difficult to diagnose because of the few objective physical signs and normal nerve conduction studies. Diagnosis of SFN is made on the basis of the clinical features, normal nerve conduction studies, and abnormal specialized tests of small fiber function. These specialized studies include assessment of epidermal nerve fiber density as well as sudomotor, quantitative sensory, and cardiovagal testing. Unless an underlying disease is identified, treatment is usually directed toward alleviation of neuropathic pain.

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Friction on the Tool-chip Interface Under Liquid Nitrogen Cooling (공구와 칩 사이에서의 Liquid Nitrogen의 마찰 효과)

  • Jun Seong Chan
    • Journal of the Korea Safety Management & Science
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    • v.4 no.2
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    • pp.237-249
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    • 2002
  • A cutting fluid can improve machining quality and tool life by maintaining the tool toughness and by providing a lubrication effect to reduce the friction between the chip and tool interface. Although liquid nitrogen as an environmentally safe coolant has been widely recognized in cryogenic machining, its function as a lubricant is plausible due to its chemical inertness, physical volatility and low viscosity. Since a reduced friction is a direct witness of the lubrication effect from a tribological viewpoint, this paper presents an evaluation of the apparent friction coefficient on the tool-chip interface in cryogenic cutting operations to prove and characterize the lubricity of LN2 in cryogenic machining. The mathematical approaches have been formulated to derive the normal and frictional forces on the tool-chip interface for the oblique cutting tests.