• Journal of Mechanical Science and Technology
• /
• v.15 no.7
• /
• pp.1002-1012
• /
• 2001

The work reported here is an extensive study of tendon response to multiple cyclic tests including 3% constant peak strain level test (A-type test), 3% constant peak strain level test with two rest periods (B-type test), and 3∼4% different peak strain level test (C-type test). A sufficient number of specimens were tested at each type of the test to statistically evaluate many changes in response during testing and differences in response between each type of the test. In cyclic tests, there were decreses (relaxations) in the peak stresses and hysteresis, increases in the slack strains, and during lower peak strain level (3%) cyclic block after higher peak strain level (4%) cyclic block in the C-type tests. Considering the results of this study and those of the other study of multiple cyclic tests with rest periods by Hubbard and Chun, 1985, recovery phenomena during the rest periods occurred predominantly at the beginning of the rest periods. Consistently in both studies, the effects of rest periods were small and transient compared to the effects of the cyclic extensions. The recovery with cycles at lower peak strain level (3%) after higher peak strain level (4%) in the C-type test has not been previously documented. This recovery seems to be a natural phenomena in tissue behavior so that collagenous structures recover during periods of decreased demand.

• Journal of the Korean Mathematical Society
• /
• v.50 no.4
• /
• pp.879-897
• /
• 2013

Shannon entropy is one of the widely used randomness measures especially for cryptographic applications. However, the conventional entropy tests are less sensitive to the inter-bit dependency in random samples. In this paper, we propose new online randomness test schemes for true random number generators (TRNGs) based on the mutual information between consecutive ${\kappa}$-bit output blocks for testing of inter-bit dependency in random samples. By estimating the block entropies of distinct lengths at the same time, it is possible to measure the mutual information, which is closely related to the amount of the statistical dependency between two consecutive data blocks. In addition, we propose a new estimation method for entropies, which accumulates intermediate values of the number of frequencies. The proposed method can estimate entropy with less samples than Maurer-Coron type entropy test can. By numerical simulations, it is shown that the new proposed scheme can be used as a reliable online entropy estimator for TRNGs used by cryptographic modules.

• Journal of the Korea Concrete Institute
• /
• v.17 no.1 s.85
• /
• pp.149-155
• /
• 2005

The purpose of this study is to investigate the flexural strengthening effects of CF(Carbon Fiber) sheet for the full-scale RC beams with multi-layer CF sheets. The partial strength reduction factors of CF sheets are suggested from the full-scale RC beams tests strengthened with multi-layer CF sheets up to six layers as well as material tests. From the material tensile tests, it was observed that the average tensile strengths of CF sheets per layer are decreased as the number of CF sheets is increased. Also the steep strength reductions of CF sheets in material test results at rupture are observed compared with the structural tests results for the full-scale RC beams strengthened with multi-layer CF sheets. Finally, the partial strength reduction factors far CF sheets up to six layers are suggested considering the effects of multi-layer and unit weight of CF sheets.

• Plant Biotechnology Reports
• /
• v.2 no.1
• /
• pp.47-58
• /
• 2008

To select agronomically useful transgenic plants, a large number of transgenic events are initially produced, gene transfer confirmed, and advanced to obtain homozygous lines for testing in field trials. Direct in planta assays for identifying the transgene carriers in the segregating progeny are based on the activity of selectable marker gene and are easy, simple and inexpensive. For this purpose, expression of bar gene as measured by tolerance to damage by glufosinate ammonium, the active ingredient in the herbicide BASTA, was investigated. Dose damage curves were generated by leaf paint tests with BASTA on four genotypes of sorghum. Transgenic plants were characterized in terms of sensitivity to the concentration of glufosinate ammonium. In transgenics, symptoms of BASTA swab tests at different growth stages and PCR analysis for cry1B were carried out and correlated. Germination tests could not be employed for large scale evaluation of transgenic progeny because of mortality of tolerant seedlings after transplantation to soil. Based on the above findings, a simple, inexpensive, time-saving, two-step scheme for effective evaluation of transgenics and their progeny containing bar gene as selection marker using BASTA swab tests is described.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.28 no.3
• /
• pp.141-147
• /
• 2024

Earthquakes of magnitude 3.0 or greater occur in Korea about 10 times on average yearly, and the number of earthquakes occurring in Korea is increasing. As many earthquakes have recently occurred, interest in the safety of nuclear power plants has increased. Nuclear power plants are equipped with many cabinet-type control facilities to regulate safety facilities, and function maintenance is required during an earthquake. The seismic performance of the cabinet is divided into structural and functional performances. Structural performance can be secured during the design procedure. Functional performance depends on the vibration performance of the component. Therefore, it is necessary to confirm the seismic performance of the components. Generally, seismic performance is confirmed through seismic simulation tests. When checking seismic performance through seismic simulation tests, it is difficult to determine the effect of frequency and maximum acceleration on an element. In this paper, shaking table tests were performed using various frequencies and various maximum accelerations. The seismic performance characteristics of the functions of electrical equipment components were confirmed through tests.

• Progress in Superconductivity and Cryogenics
• /
• v.25 no.4
• /
• pp.28-31
• /
• 2023

This study presents a comprehensive procedure for the low cycle fatigue test of ultrasonically welded (UW) coated conductor (CC) lap-joints. The entire process is examined in detail, from the robust fabrication of the UW REBCO CC joints to the reliability testing under a low number of repeated cycle fatigue conditions. A continuous I_c measurement system enables real-time monitoring of I_c variations throughout the fatigue tests. The study aims to provide a step-by-step procedure that involves joint fabrication, electromechanical property (EMP) tests under uniaxial tension for stress level determination, and subsequent low-cycle fatigue tests. The joints are fabricated using a hybrid method that combines UW with adding In-Sn soldering, achieving a flux-free hybrid welding approach (UW-HW flux-free). The selected conditions for the low cycle fatigue tests include a stress ratio of R=0.1 and a frequency of 0.02 Hz. The results reveal some insights into the fatigue behavior, irreversible changes, and cumulative damage in the CC joints.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.229-231
• /
• 1994

For the effective use of satellite communication transponder, tests for the payload system such as IOT(In-Orbit Test), RPM(Routine Payload Monitoring), CSM(Communicatios System Monitoring), and REV(Remote Earth-Station Verification) have to be conducted. Those tests are used in order to verify the condition and generic design of the satellite, to provide a database for operational calculations, and to maintain the quality of communication services. As the satellite communication system gets with wider expansion with higher complexity of operation, tests for the communication system also need more complex operation that usesophisticated computer-controlled measuring system. For and C language based measurement functions, which uses GPIB protocol and SCPI commands. But SICL requires knowledge of BASIC and C language as well as GPIB and SCPL system. This paper introduces a new language called CALSTEP-Control and Access Language for the Systems of Test Equipment and Payload. This language is designed for the operator to perform the tests for the satellite communication system without any special knowledge that is mentioned above. This language has very limited number of commands which are to be used to control the payload system and test equipments to perform IOT and CSM, and those commands are very readable and easy to understand, so an operator without any knowledge of BASIC and C programming language, or SICL and SCPI command can use it.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.25 no.3
• /
• pp.254-284
• /
• 2015

Objectives: There is a requirement to select target materials for mutagenicity(Genotoxicity) testing, so we determined to set the test priorities of them by searching the related database. Methods and Results: We searched a number of databases to find information on mutagenicity tests with chemicals under the Occupational Safety and Health Act(OSH Act), such as KOSHANET, National Toxicology Program(NTP), European Chemicals Agency(ECHA), US National Library of Medicine(NLM), and Genetic Toxicology Data Bank(GENE-TOX), as well as ChemIDplus webpage, and presented the information. Also we anticipated their hazards with ACToR sites to confirm the 58 mutagenicity(Genotoxicity) tests we will perform. Conclusions: We presented target materials for mutagenicity testing with specific GLP tests consisting of reverse mutation(Ames), chromosomal aberration and micronucleus test.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.9
• /
• pp.842-850
• /
• 2003

The suspension insulators are subjected to harsh environments in service for a long time. The long-term reliability of tile insulators is required for both mechanical and electrical performances. This study describes some basic performance tests and accelerated aging test by cool-heat cycling methods and thermal mechanical performance test methods on alumina porcelain insulators (new and aged) used for transmission line in KOREA. There was no fail in electrical and mechanical performance tests such as a high voltage strength, a flashover voltage, and an impact strength in all samples. But in the case of accelerating aging tests which have above 9$0^{\circ}C$ temperature gradient, fracture phenomena was happened by a thermal shock in tile aged sample(sample A) with low alumina porcelain body. It was indicated that sample A was more severely aged than other samples. According to results of HRB test and microstructural analysis, it was reasoned that insulator bodies with the matrix reinforced with alumina crystalline phase have advantages over the suppression of crack advance. And cool-heat aging and mechanical thermal ageing tests shows that a temperature gradient is more effective to accelerating than a cycling number.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.3 s.62
• /
• pp.481-489
• /
• 1998

Injuries and infectious diseases have been the most important public health problems since the beginning of human life. Injuries result in death of about 30,000 people each year in South Korea. In terms of years of life lost, injuries are considerably more costly than either heart disease or cancer. In terms of cost - both the direct costs of care and the indirect costs to individuals, families, and societies of a diminished life-injuries are among the most expensive of all social problems. The main purposes of this study are (1) to describe the outcomes as well as treatment process of brain injured patients and (2) to identify the factors impacting on length of stay during hospitalization and hospital fees. The research method used in this study was to review the medical records of five hundreds brain injured cases using systemic random sampling. The multiple logistic regression was administered to identify the factors impacting on the outcomes. The results are as follow : (1) the consultation .ate was found to be 72.9% while referral rate was 11.2%; (2) nearly 30% of the respondents were hospitalized over 30 days; (3) multiple logistic regression analyses revealed that the determinants influencing LOS were number of consultations, number of lab tests, and surgery; (4) the determinants of hospital fee were severity of brain injury, gender of patients, number of consultations, number of lab tests, and surgery.