• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.162-171
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• 2023

In this study, The details for a seismic adapter designed to easily connect concrete structures and reinforcement materials for the in-plane reinforcement of aged structures were proposed. Proposed seismic adapter was tested for performance using a dynamic simulation on a 2-story column-beam structure, scaled to half of the real size. The experimental results showed that the reinforced test specimens using the seismic adapter improved their energy dissipation capacity by 3.5 times compared to the non-reinforced specimens. It was confirmed that the seismic adapter experienced no damage within its general usage range, thus proving its effectiveness. Subsequently, upon loading until the limit of deformation (a deformation angle of 3.3%), it was observed that one of the M10 bolts connecting the adapter and the reinforcement at the lower part of the first floor broke. Considering this finding, when applying seismic retrofitting in real situations, emphasis should be placed on the design of the bolts and anchors connecting the seismic adapter. This aspect warrants further research for validation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.61-69
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• 2024

An ultra-high strength prestressed prismatic beam of 100 MPa in compressive strength was developed by increasing the water-tightness of concrete by utilizing centrifugal molding processes without adding expensive admixtures. The centrifugal prismatic PSC beam developed as the superstructure of the avalanche tunnel was constructed on a rahmen bridge in a small local river. In this study, the centrifugal prismatic beam was compared and analyzed based on the results of measurements made through static load tests and the results of numerical analysis of the target structure. The common load-carrying capacity and safety of the rahmen bridge were evaluated. The static·dynamic load tests and finite element analysis results of this bridge were similar, and it was confirmed that the behavior of the centrifugal prismatic beam was well simulated. All centrifugally formed square beams that make up the composite rahmen bridge were evaluated to secure sufficient load carrying capacity under the design live load, and structural reliability was proven by ensuring safety.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.2
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• pp.9-16
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• 2024

In this paper, we aimed to convert the fire curve in volume units to a fire curve per unit area for application in the Fire Dynamic Simulator (FDS) surface heat release rate method. The fire curve was expressed dimensionlessly considering the total combustion characteristic time, and improvements were made to represent the appropriate ratios for the growth , steady, and decay phases concerning the fire intensity. Additionally, a correction function for combustion characteristic time varying with mass increase was derived. Also to control the growth time values according to the increase in mass, a function to correct the growth phase ratio was derived. Consequently, utilizing existing data, a formula was established to determine the reference mass for combustion materials and predict the fire curve based on mass increase.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.59-65
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• 2024

In this study, in order to improve the mechanical properties and durability of asphalt mixtures, a modifier (CSM, Cationized Silicate Modifier) was applied to asphalt to derive optimal mixing ratio conditions. Design of asphalt mixture using modified asphalt binder was conducted, and moisture resistance and dynamic stability were evaluated for optimal mixing conditions. The evaluation results showed that it exceeded the standards stipulated in the relevant guidelines, and as a result of conducting a water permeability test on the optimal mixing condition, it was confirmed that impermeable performance was secured. As a result of examining the noise reduction performance through field test, a noise reduction performance of about 10 dB was secured compared to before paving. It will be necessary to secure reliability through continuous noise generation evaluation in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.185-194
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• 1995

The prevention of excessive use of nitrogen fertilizer get an attention in Korea not only for minimizing $NO_3^-$ contamination of groundwater but also for establishment of environmental friendly sustainable agriculture. In order to find out the dynamics of $NO_3^-$ in barley rhizosphere and its suitability for nitrogen fertilization strategies and for environmental control, the accumulation of $NO_3^-$ in 3 layer, 0~30cm, 30~60cm, 60~90cm of soil profile has been detected in winter barley pro-duction system. It showed the recommended N fertilization rate for winter barley cause the $NO_3^-$ contamination of groundwater through $NO_3^-$ leaching during winter. The $NO_3^-$ content of 0~90cm soil depth have directly reflected the amount of basal N fertilization in the early spring, but not 0~30cm and 0~60cm soil depth. The contents of $NO_3^-$ measured to 0~30cm, 0~60cm soil depth were not significanly correlated with yield but the contents of $NO_3^-$ measured to 90cm soil depth was highly correlated with yield. Nitrogen fertilizer requirement could be estimated accurately by soil test and it provides field specific N rate recommendation for spring N application to winter barley. It was concluded that $N_{min}$ method could be applied to korean climatic and soil condition for optimal fertilizer application rate.

• 대한공업교육학회지
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• v.34 no.2
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• pp.205-229
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• 2009

The purpose of this study is to verify the effect of forming groups according to the brain hemisphere preference on the cooperative problem solving learning achievement in the middle school technology. The subjects of this study were 95 second grade boy students of a middle school in Daejeon and the measurement instrument of the left and right hemisphere preference is the Brain preference Indicator(BPI) which had been developed by Torrance et al(1977) and was adjusted by Ko, Younghee(1991). The academic achievement was analyzed on cognitive, psychomotor and affective domains. Derived results from this research are stated below: First, making groups according that the brain preference is more similar was more effective than making groups according to the high familiarity and the similarity of performance in the academic achievement of psychomotor and affective domains. Second, making groups according that the brain preference is more similar was more effective than making groups according that the brain preference is more diffrent for the academic achievement of affective domains on the cooperative problem solving learning in technology. Third, the academic achievement score of the right hemisphere preference group is higher than the score of the population in three domains. Also, the academic achievement score of the right hemisphere preference group is higher than the score of the left hemisphere preference group.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.227-236
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• 2016

Dynamic positron emission tomography(dPET) is widely used medical imaging modality that can provide both physiological and functional neuro-image for diagnosing various brain disease. However, dPET images have low spatial-resolution and high noise level during spatio-temporal analysis (three-dimensional spatial information + one-dimensional time information), there by limiting clinical utilization. In order to overcome these issues for the spatio-temporal analysis, a novel computational technique was introduced in this paper. The computational technique based on singular value decomposition classifies multiple independent components. Signal components can be distinguished from the classified independent components. The results show that signal to noise ratio was improved up to 30% compared with the original images. We believe that the proposed computational technique in dPET can be useful tool for various clinical / research applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.597-604
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• 2017

This study examined the effects of vestibular stimulation training on the static and dynamic balance of patients with chronic stroke. This study was conducted from July 15th to September 6th, 2014 and 20 subjects diagnosed with stroke participated in this study. The subjects were divided randomly into Group I (general therapeutic exercise, n=10) and Group II (vestibular stimulation training, n=10). Both groups were trained for 40 minutes, 3 times a week, for 6 weeks. The balance ability, static balance and dynamic balance, were evaluated using a Good Balance System and compared before-and-after intervention. In the vestibular training group, there were statistically significant differences in the left-right and anterior-posterior balance with the eyes closed and standing posture, in the left-right and anterior-posterior balance with the eyes open and standing posture, and moving time and distance. In the general therapeutic exercise group, there was no significant difference except in the left-right balance with the eyes open and standing posture. In conclusion, vestibular stimulation training had positive effects on the static and dynamic balance of chronic stroke patients, and this training can be effective in a treatment program to improve the balance ability of stroke patients.

• The Korean Society of Law and Medicine
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• v.20 no.2
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• pp.111-140
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• 2019

The Bioethics and Safety Act provides a set of rules to regulate biobanks and research activities using human biological material, but the law seems to be defective in several folds. The law requires that, prior to collection or use of human biological materials, researchers should obtain the informed consent of the donors, but the law does not obligate biobanks to do so. Even in cases where the law requires informed consent, the ordinance of the Ministry of Health and Welfare allows open (or blanket) consent. In addition, a new article in the Act, Article 42-2 which will take effect from October 24, 2019, allows medical institutions to provide biobanks with remaining biospecimens collected in the course of diagnosis and treatment, unless the donors express their intent to opt-out, without obtaining specific consent from them. Given the need to protect the autonomy of donors and the unique characteristics of biobanks and research activities that use human biological materials, this paper concludes that such open consent-based law may not be suitable to protect the autonomy of the donors and that the broad consent requirement may be a desirable policy option. The paper acknowledges that the international community has long questioned whether broad consent (as well as open consent) is an effective choice to regulate the use of human biological materials. The paper stresses that the baseline requirement in designing the law is that the secondary use of human biological materials should be based on informed consent of the donors; the core value of the law should be a governance structure that promotes transparency and protects donor participation.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.126-134
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• 2015

A sleep disorder is being recognized as one of the major health issues related to high levels of stress. At the same time, interests about quality of sleep are rapidly increasing. However, diagnosing sleep disorder is not a simple task because patients should undergo polysomnography test, which requires a long time and high cost. To solve this problem, an accelerometer embedded wrist-worn device is being considered as a simple and low cost solution. However, conventional methods determine a state of user to "sleep" or "wake" according to whether values of individual section's accelerometer data exceed a certain threshold or not. As a result, a high miss-classification rate is observed due to user's intermittent movements while sleeping and tiny movements while awake. In this paper, we propose a novel method that resolves the above problems by employing a dynamic classifier which evaluates a similarity between the neighboring data scores obtained from SVM classifier. A performance of the proposed method is evaluated using 50 data sets and its superiority is verified by achieving 88.9% accuracy, 88.9% sensitivity, and 88.5% specificity.