• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.901-911
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• 2015

This article starts with a review of the e-self directed learning, future time perspective and decision making, especially in relation to the career myths. In particular, we empirically analyzed the factors affecting the future time perspective and the decision making on the characteristics of career myths(e.g. relatedness of the test myths, the supreme myth and the family myths). Hence the main purpose of this article is to suggest an empirical model explaining how these factors affect e-self directed learning to future time perspective and decision making. Furthermore, we suggested an expanded model about future time perspective, decision making and especially in relation to the career myths. We founded that the e-self directed learning significantly affect the future time perspective and the decision making, also the future time perspective affect the test myths and family myths except the supreme myths and the decision making significantly affect the career myths(i.e., the test myths, the supreme myth, the family myths).

• Journal of the Korea Society of Computer and Information
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• v.23 no.2
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• pp.9-16
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• 2018

Recently, as various IP set-top boxes based on Android OS have been widely used in general households and public facilities, complaints about services and set-top boxes have continued to increase as much as other smart devices. In order to reduce this problem, the manufacturer performs the testing work before the product is commercialized. However, the testing can reduce potential defects in the product, but it can not prove that the product is free of defects. Therefore, the quality of the product can vary depending on how effective testing techniques are introduced. In this paper, we propose a new exploratory testing method that minimizes test case creation time and makes it easier to plan and execute test while simultaneously learning how to run the product under test. Using the first proposed method, the test time is reduced by about 16.7 hours and the defect detection rate is 25.4% higher than the formal specification-based testing method. Informally, the test time was shortened by about 4.7 hours and the defect detection rate was 13% higher than the informal experience-based testing method.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.5
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• pp.11-24
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• 2011

A real-time hybrid test of a 3 story-3 bay reinforced concrete frame which is divided into numerical and physical substructure models under uniaxial earthquake excitation was run using a fixed iteration implicit HHT time integration method. The first story inner non-ductile column was selected as the physical substructure model, and uniaxial earthquake excitation was applied to the numerical model until the specimen failed due to severe damage. A finite-element analysis program, Mercury, was newly developed and optimized for a real-time hybrid test. The drift ratio based on the top horizontal displacement of the physical substructure model was compared with the result of a numerical simulation by OpenSees and the result of a shaking table test. The experiment in this paper is one of the most complex real-time hybrid tests, and the description of the hardware, algorithm and models is presented in detail. If there is an improvement in the numerical model, the evaluation of the tangent stiffness matrix of the physical substructure model in the finite element analysis program and better software to reduce the computational time of the element state determination for the force-based beam-column element, then the comparison with the results of the real-time hybrid test and the shaking table test deserves to make a recommendation. In addition, for the goal of a "Numerical simulation of the complex structures under dynamic loading", the real time hybrid test has enough merit as an alternative to dynamic experiments of large and complex structures.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.341-358
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• 2021

Purpose: After product development, a Reliability Demonstration Test(RDT) is performed to confirm that the target life has been achieved. In the RDT, there are cases where the test equipment cannot accommodate all samples. Therefore, this study considers a test method to most economically demonstrate the target life of the product at a certain confidence level when the sample size is larger than the capacity of the test equipment. Methods: If the sample size is larger than the capacity of the test equipment, test equipments may be added or the test time of individual samples may be increased. So the test method is designed to cover this situation with limited capacity. A zero-failure test method is applied as a test method to RDT. To minimize the cost, the test cost is defined and the cost function is obtained. Finally, we obtain the optimal test plan. Results: A zero-failure test method is designed when the sample size is larger than the capacity of the test equipment, and the expected total cost is derived. In addition, the process of calculating the appropriate sample size, test time, and number of test equipment is illustrated through an example, and the effects of model parameters to the optimal solutions are investigated numerically. Conclusion: In this paper, we study a zero-failure RDT with test equipment that has limited capacity. The expected total cost is derived and the optimal sample size, test time, and number of test equipment are determined to minimize the expected total cost. We also studied numerical examples and for further studies, we can relax some restrictions in the test model and optimize the test method.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.3
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• pp.32-36
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• 2016

Test equipment was designed and manufactured to evaluate thermal reaction characteristic of internal insulators of solid rocket motor. Test is allowed up to chamber pressure 2,500 psi, burn-time 100 s. A cross section of test sample part is quadrature, and various test samples can be comparable at the same time. Inner temperature of test sample can be measured by thermocouples during burning. Test was executed in condition of efficient average chamber pressure 1,000 psi, efficient burn-time 10 s and safety of equipment was confirmed. Basic data for understanding thermal characteristics of internal insulator, that is, pressure-time curve, temperature-time curve in the test sample, and thermal destruction thickness of test sample was gained successfully.

• Physical Therapy Korea
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• v.21 no.3
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• pp.80-88
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• 2014

Previous studies have reported that decreased cognitive ability has been consistently associated with significant declines in performance of one or both tasks under a dual-task walking condition. This study examined the relationship between specific cognitive abilities and the dual-task costs (DTCs) of spatio-temporal gait parameters in stroke patients. The spatio-temporal gait parameters were measured among 30 stroke patients while walking with and without a cognitive task (Stroop Word-Color Task) at the study participant's preferred walking speed. Cognitive abilities were measured using Computerized Neuropsychological Testing. Pearson's correlation coefficients (r) were calculated to quantify the associations between the neuropsychological measures and the DTCs in the spatio-temporal gait parameters. Moderate to strong correlations were found between the Auditory Continuous Performance test (ACPT) and the DTCs of the Single Support Time of Non-paretic (r=.37), the Trail Making A (TMA) test and the DTCs of Velocity (r=.71), TMA test and the DTCs of the Step Length of Paretic (r=.37), TMA test and the DTCs of the Step Length Non-paretic (r=.36), the Trail Making B (TMB) test and the DTCs of Velocity (r=.70), the Stroop Word-Color test and the DTCs of Velocity (r=-.40), Visual-span Backward (V-span B) test and the DTCs of Velocity (r=-.41), V-span B test and the DTCs of the Double Support Time of Non-paretic (r=.38), Digit-span Forward test and the DTCs of the Step Time of Non-paretic (r=-.39), and Digit-span Backward test and the DTCs of the Single Support Time of Paretic (r=.36). Especially TMA test and TMB test were found to be more strongly correlated to the DTCs of gait velocity than the other correlations. Understanding these cognitive features will provide guidance for identifying dual- task walking ability.

• The KSFM Journal of Fluid Machinery
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• v.16 no.5
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• pp.18-23
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• 2013

Thermal aging test is performed to qualify the life time of equipment in thermally aged condition. Due to long life time more than 10 years like as in power plant, the equipment is subjected to the accelerated thermal aging condition which is able to shorten the long aging test period by increasing aging temperature. Normally, conservatism of thermal aging test causes to impose unbalanced and excessive thermal load on components of the equipment, and deformation and damage problems of the components. Additionally, temperature rise of each component through heat generation of the electric equipment leads to long-term problem of the test period. Multi-phase accelerating aging test is to perform thermal aging test in multiple aging conditions after dividing into groups with various components of equipment. The groups might be classified considering various factors such as activation energy, temperature rise, glass transition temperature and melting temperature. In this study, we verify that the multi-phase accelerating aging test method can reduce and equalize the thermal over load of the components and shorten aging test time.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.7
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• pp.526-531
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• 2003

Recently, many BIST(Built-in Self Test) schemes have been researched to reduce test time and hardware. But, most BIST schemes about pattern generation are for deterministic pattern generation. In this paper a new pseudo-random BIST scheme is provided to reduce the existing test hardware and keep a reasonable length of test time. Theoretical study demonstrates the possibility of the reduction of the hardware for pseudo-random test with some explanations and examples. Also the experimental results show that in the proposed test scheme the hardware for the pseudo-random test is much less than in the previous scheme and provide comparison of test time between the proposed scheme and the current one.

• Journal of Electrical Engineering and information Science
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• v.3 no.3
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• pp.396-401
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• 1998

An optimal algorithm is presented for feasibility test and scheduling of real-time tasks where tasks are preemptable and created dynamically. Each task has an arbitrary creation time, ready time, maximum execution time, and deadline. Feasibility test and scheduling are conducted via the same algorithm. Time complexity of the algorithm is O(n) for each newly created task where n is the number of tasks. This result improves the previous result of O(n log n). It is shown that the algorithm can be used for scheduling tasks with different levels of importance. Time complexity of the algorithm for the problem is O(n\ulcorner) which improves the previous results of O(n\ulcorner log n).

• Journal of the Korean Society of Safety
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• v.6 no.4
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• pp.34-44
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• 1991

In this study, the general solution of heat balance equation including conductive heat loss were suggested and were determined the constants with the results of experiment in hot tunnel in order to derive the general equation for the response time and to investigate the response time index which represent the characteristics of response of sprinkler head in actual fires. Two types of test were considered, the plunge test, in which the air temperature is represented by a step function, and the ramp test, in which the air temperature increases at a constant rate. As a result, simple equations were derived, which can be predicted the response time for the ramp type fire with the rate of temperature rise and gas velocity, for the plunge type fire with temperature and gas velocity. Also other useful data, such as the effective temperature, time constant, response time index and conduction parameter were obtained.