• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2004.05a
• /
• pp.41-44
• /
• 2004

Recently, in the case of domestic, for all that the deterioration environment about the carbonation of reinforced concrete structures is accelerated, systematic diagnosis and researches are not completed. And the selection techniques of repair material and method used under the situation that the indicator and the performance evaluation method are nor established are dependant on existing experience. Therefore, the purpose of this study is intend to present fundamental data for the reasonable selection of repair material and method. durability design and longevity on the deteriorated reinforced concrete structures, through computing the carbonation depth and velocity coefficient by accelerating carbonation test under various accelerating conditions and investigating the application of carbonation evaluation method. The results of this study are as follow; The resistances to carbonation are increased when the W/C ratio if lower and the treatment of surface coating is executed. And the carbonation depth and velocity coefficient according to accelerating carbonation test conditions are increased when the conditions of temperature, relative humidity and $CO_2$density are higher individually.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.1
• /
• pp.57-62
• /
• 2005

Grid-connected photovoltaic (PV) systems were installed and monitored at the field demonstration test center (FDTC) in Korea in October 2002. Before long-term field testing of installed PV systems, the performances of PV components were evaluated and compared through short-term performance tests of each of the PV system components such as power conditioning system and PV module under standard test conditions. A data acquisition system has been constructed for measuring and analyzing the performance of PV systems to observe the overall effect of environmental conditions on their operation characteristics. Performances of PV systems have been evaluated and analyzed not only for component perspective (PV array, power conditioning unit) but also for global perspective (system efficiency, capacity factor, electrical power energy) by review of the field test and loss factors of the systems. These results indicate that it is highly imperative to develop an optimum design technology of grid connected PV systems. The objective of this paper is not only to evaluate and analyze the performance of domestic PV systems application through long-term field testing at FDTC but also to develop evaluation, analysis and optimum technology for long-term stability and reliability of grid-connected PV systems in Korea.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.3
• /
• pp.265-273
• /
• 2020

Objective: The aim of this study was to investigate the effect of participation in contact sports on neurocognitive scores, dual-task walking velocity, and cognitive costs in retired athletes. Method: Forty-four retired athletes (mean age = 26.4±5.5 yrs) and thirty-eight controls (mean age = 26.1±4.9 yrs) participated in this study. Neurocognitive score was collected using computerized neurocognitive testing using RehaCom. Gait velocity was collected one single task, four dual-tasks, and two multi-tasks using Optogait. Mann-Whitney U test was performed to compared differences in cognitive scores among groups. A mixed-design two-way ANOVA and Bonferroni posthoc test were used to assess the effect of group and walking tasks for each condition. Results: The auditory divided attention of neurocognitive score of retired athletes was higher than the control group (p < 0.05). No statistical differences were observed in the other neurocognitive scores between groups. The changes in walking velocity and cognitive costs according to the dual-task walking tests differed between the two groups (p < 0.05). Conclusion: Although participation in contact sports did not affect the neurocognitive results of retired athletes, it could be confirmed that the reduction in walking velocity and an increase in cognitive costs during dual-task walking. Rather than observing only neurocognitive scores as a single evaluation item for cognitive evaluation of retired athletes in relation to daily life, the application of the dual-task gait test may provide useful information.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.04a
• /
• pp.401-406
• /
• 2013

This paper presents experimental evaluation of IRE (isolation roller bearing) seismic isolation device. From the combination of base isolation on the IRE system displacement response spectrum and acceleration response spectrum, the compressive strength and the coefficient of friction experiments. Also the IRE system is evaluated by environment test according to KS standards. Both the resonance and seismic experiments using a combination of the IRE and Natural Rubber Bearing (NRB) are performed in order to analyze the seismic isolation of the IRE system dynamic characteristics. For the given load and exciting frequency, the resonant frequency becomes lower, but the resonant magnification remains to be same. However, it is shown that when we consider the IRE only, the vibration on the table with the horizontal movement and the independent horizontal displacement due to the rolling motion of the plate and roller are significantly reduced. This result verifies that the proposed optimal design method of the IRE system is very effective.

• Journal of Engineering Education Research
• /
• v.17 no.4
• /
• pp.21-24
• /
• 2014

The purpose of this study is to develop the engineering students leadership program and evaluate the pilot test. To this end, literature reviews covering various leadership programs were studied and a needs analysis survey was conducted. The needs analysis survey found that student subjects believe leadership to be an important quality, but that the current availability of leadership training programs is lacking. Furthermore, results of the study are as follows, with respective results listed in descending order. The majority of students selected on-line learning as their preferred training method, followed by blended learning and in-person learning. Students also indicated their preferred instructional method to be through on-line courses. Based on these results, a preliminary pilot program was experimentally launched for only 1 class's use. This process of the development for the Engineering Leadership Program consists of 4 stages. The first stage is a needs analysis survey, followed by the design of the program based on results from the needs analysis survey. Afterwards comes the development stage, followed by the implementation stage, comprised of two parts; the pilot test and the distribution. The final stage is the overall evaluation step. We are currently in the first step of the third stage (the pilot test) and only the overall evaluation stage remains. After the distribution, a follow-up study will be conducted to analyze the effectiveness of the implemented program.

• Journal of Korea Multimedia Society
• /
• v.10 no.7
• /
• pp.912-922
• /
• 2007

Evaluation of distance teaming systems needs a method that maintains a consistent level of difficulty for each test. In this paper, we propose a new algorithm for test sheet generation based on genetic algorithm. Unlike the existing methods that difficulty of each test item is assigned by tutors, in the proposed method, that can be adjusted by the result of the previous tests and the average difficulty of test sheet can be consistently reserved. We propose the new genetic operators to prevent duplications of test items in a test sheet and apply the adjusted difficulty of each test item. The result of simulation shows that difficulty of the test sheet generated by proposed method can be more regular than the random method and the simulated annealing method.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.1
• /
• pp.69-73
• /
• 2018

Korean-peacekeeper's transparent armors in Iraq showed delamination, cracking and clouding a decade ago. And there were also similar deterioration recurrences in KLTV during the operational test a few years ago. Also, the differences between operational capability & lab Bullet-proof test condition, and insufficiency of military protection spec resulted in incomplete bullet-proof results. Moreover, although so many ground weapon systems have been developed, there were not secure test & evaluation codes to verify transparent armoured glasses equal to advanced-overseas products. So in this study, first, environmental test codes were established that all tests should be carried out as the application of only one specimen with newly adopted thermal shock test instead of completing each test with different one. Second, protection standards were integrated through the analysis of global developed country's specifications and reinforced as adding to the real mock-up condition if vehicle's glasses are smaller than standard specimen. Hereby, by applying to test-codes which including actual operational & vehicular conditions, the gap between development test and operational environment was minimized.

• International Journal of Advanced Culture Technology
• /
• v.9 no.1
• /
• pp.210-217
• /
• 2021

In the case of an agile-based project, it was inadequate to perform a comprehensive inspection and evaluation on the establishment and operation of an information system by performing audit only with the audit and inspection elements provided by the existing information system audit and inspection system. In particular, in the case of the test activity area, it was necessary to improve the test activity audit check items to comprehensively check the agile-based development process by applying the existing audit system. To this end, a test activity improvement check model of the agile methodology audit model was presented by applying the repetition concept, a characteristic of the agile methodology. In order to empirically verify the model of this study, a survey was conducted for auditors and designers/developers who have experience in performing agile-based projects and auditing information systems. As a result of the questionnaire on the integrated test and system test in the test stage, more than 70% of the respondents were found to be suitable. More than 80% of the respondents judged that it was appropriate as a result of the questionnaire on "improvement and regression test progress according to integrated test and system test results" and "integrated test and functional actions of components and subsystems".

• Journal of the Korean Society of Propulsion Engineers
• /
• v.18 no.1
• /
• pp.50-57
• /
• 2014

A ground hot-firing test (HFT) was conducted to take out the optimal design configurations for the thrust chamber of 70 N-class liquid rocket engine under development. Monopropellant grade (purity: ${\geq}98.5%$) hydrazine was adopted as a propellant for the HFT, and three kinds of thrust chambers having characteristic lengths ($L^*$) of 2.79, 2.95, and 3.13 m were selected for their performance evaluation. It is revealed through the test and evaluation that the increase of the $L^*$ leads to a performance degradation in the test condition specified, and pulse response performance of the development model shows superior characteristics to commercialized hydrazine thrusters.

• Journal of the Korean GEO-environmental Society
• /
• v.21 no.12
• /
• pp.11-16
• /
• 2020

It is necessary to assess the proper performance of the existing rockfall prevention net in order to minimize the damage to human lives and property in the event of rockfall. However, there is no standard for performance evaluation of rockfall prevention net in Korea, and only the design of rockfall prevention net exists by calculating energy that can be absorbed energy. Therefore, laboratory pullout test was conducted for the performance evaluation of the rockfall prevention net, cuts and load-displacement characteristics of the PVC coating net used in the laboratory pullout test are determined to identify the performance of the rockfall prevention net.