• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.976-984
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• 2006

Time-temperature superposition has been studied to determine the long-term fatigue life over millions of cycles for glassy polymers. π le superposition is supposed to make an accelerated lifetime testing (ALT) technique possible. Dog-bone shaped specimens made of carbon filled Polycarbonate (PC) were tested under fatigue, based on the stress-lifetime approach (S-N curve). Fatigue-induced localized yield-like deformation is considered as the defect leading to fatigue and its evolution behavior is characterized by a modified energy activation model in which temperature is considered as fatigue acceleration factor. This model allows the reduced time concept to account for effects of different temperature in short-term fatigue data to determine long-term fatigue life through the use of time-temperature superposition that is applicable under a low frequency and isothermal conditions. The experimental results validated that the proposed technique could be a possible method for accelerated lifetime testing (ALT) of time-dependent polymeric materials.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.125-133
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• 2004

In order to test reflecting the features of a development methodology and domain, it is required to tailor process standards and perform testing according to the tailored process. However, since commercial testing tools support only a part of the tailored process, it is essential to either acquire or develop testing tools appropriate for a development environment. This paper proposes a method to develop a test process execution tool which has common features of standards, and variousness in methodologies and domains. ‘Test Process Execution Tool: Test PET’ which is a test process execution tool developed adapting the concept of product line. Our Test PET generates the test process suitable for the development methodology and domain and then executes the produced test process.

• Journal of Korean Physical Therapy Science
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• v.18 no.1
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• pp.33-49
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• 2011

The process of physical therapy uses a problem-solving approach to enhance a patients's functioning status. The International Classification of Functioning, Disability and Health(ICF) is the common concept for the functioning in the world. Physical therapists require the ability to identify problems, formulate hypothesis, and plan intervention strategies through clinical reasoning. In the clinical process, physical therapists need to use standard and common languages in speech and in documentation. The purpose of this study was to suggest the process of making strategy for efficient intervention, examining and evaluating the functional problem of the person with stroke using ICF tools. For the first step in this process model, therapists could list the information relating to functional problems used by the ICF Core set and then could identify the interaction among the problems using the ICF assessment sheet. For the next step, therapist is needed to make the hypothesis and hypothesis testing, and then set a primary functional goals and therapeutic goals in detail after prioritizing the problems to be managed based on the problem list. Finally, after setting the identified problems as the purpose of intervention through the hypothesis testing, therapist could do some intervention after making a plan to solve these problems, and find out the outcomes using the ICF evaluation display. This report illustrates how to apply the process based on ICF concept into physical therapy practice. Making a decision for the most efficient intervention requires that therapists use the clinical reasoning process based on ICF concept.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.229-236
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• 2018

Accident-tolerant fuels (ATFs) are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding). This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc.) serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS) technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD), laser coating, or Chemical vapor deposition techniques (CVD), the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions ($500^{\circ}C$ steam, $1200^{\circ}C$ steam, and Pressurized water reactor (PWR) pressurization test) and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1598-1608
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• 1999

Performance testing for ATM network deals with evaluation of maximal throughput of network by measuring and analyzing of various performance parameters. However, because of the absence of the methodology and framework for performance testing, the results of performance measurements for same implementation under test were much relied on tester. In this paper, the concept of ATM performance testing is described in both cell and frame level and a framework of ATM performance testing is suggested by describing of testing environment for performance measurement and requirements of performance evaluation. For this, we define performance measuring method and parameters for each case.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.11
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• pp.549-554
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• 2016

ConceptNet is a common sense knowledge base which is formed in a semantic graph whose nodes represent concepts and edges show relationships between concepts. As it is difficult to make knowledge base integrity, a knowledge base often suffers from incompleteness problem. Therefore the quality of reasoning performed over such knowledge bases is sometimes unreliable. This work presents neural tensor networks which can alleviate the problem of knowledge bases incompleteness by reasoning new assertions and adding them into ConceptNet. The neural tensor networks are trained with a collection of assertions extracted from ConceptNet. The input of the networks is two concepts, and the output is the confidence score, telling how possible the connection between two concepts is under a specified relationship. The neural tensor networks can expand the usefulness of ConceptNet by increasing the degree of nodes. The accuracy of the neural tensor networks is 87.7% on testing data set. Also the neural tensor networks can predict a new assertion which does not exist in ConceptNet with an accuracy 85.01%.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.735-737
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• 2002

A current transformer for measuring current in high power testing laboratory is exactly proportional to the current including D.C component due to electrical transient. But, current transformer isn't designed to consider D.C component, therefore when data acquisition system measure that current. the error is increased because of saturation of core. This paper describe the concept of transient factor and how to design the current transformer.

• Journal of the Korean Statistical Society
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• v.35 no.2
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• pp.167-177
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• 2006

An important role of statistical analysis in science is interpreting observed data as evidence, that is 'what do the data say?'. Although standard statistical methods (hypothesis testing, estimation, confidence intervals) are routinely used for this purpose, the theory behind those methods contains no defined concept of evidence and no answer to the basic question 'when is it correct to say that a given body of data represent evidence supporting one statistical hypothesis against another?' (Royall, 1997). In this article, we use likelihood ratios to measure evidence provided by record values in favor of a hypothesis and against an alternative. This hypothesis is concerned on mean of an exponential model and prediction of future record values.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.6
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• pp.527-538
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• 2010

This paper presents a nondestructive evaluation approach for system identification (SID) of real railway bridges using field vibration test results. First, a multi-phase SID scheme designed on the basis of eigenvalue sensitivity concept is presented. Next, the proposed multi-phase approach is evaluated from field vibration tests on a real railway bridge (Wondongcheon bridge) located in Yangsan, Korea. On the steel girder bridge, a few natural frequencies and mode shapes are experimentally measured under the ambient vibration condition. The corresponding modal parameters are numerically calculated from a three-dimensional finite element (FE) model established for the target bridge. Eigenvalue sensitivities are analyzed for potential model-updating parameters of the FE model. Then, structural subsystems are identified phase-by-phase using the proposed model-updating procedure. Based on model-updating results, a baseline model and a nondestructive evaluation of test bridge are identified.

• Journal of the Korean Society for Nondestructive Testing
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• v.4 no.2
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• pp.20-29
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• 1985

There are two basic concepts in industrial radiographic examination; one is a radio-graphic sensitivity, and the other is a acceptance criteria. The comparison of these main points are studied for KS Standard and ASME Boiler and Pressure Vessel Code. From the results of the experiment, higher radiographic sensitivity is required in KS Standard when the thickness of material to be examined is less than 20mm in single wall technique. The acceptance criteria for linear type indications are described on same concept in two standards, whereas the acceptance criteria for rounded indications of KS Standard which mainly depends upon the object thickness are more severe than those of ASME BPV Code.