• Proceedings of the KSR Conference
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• 2009.05a
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• pp.612-618
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• 2009

Recently the roles of railways about the prevention of global warming caused by greenhouse gases and for low carbon green growth are larger than ever. And the railroad-related research institutions have been active in researching for energy conservation. Especially the urban railroad has been emerged as the best means of transportation compared to the general public transportation systems in punctuality, stability, ecology and etc. In operating the urban railroad system there are various ways for energy savings. In the larger category, One is the hardware aspect according to the structure of the vehicle and the development of control systems. The other is the software aspect which efficient train operation can be made through control of driving patterns and driving diagram. In this paper, there is sense to analyze the result in verifying expectation relation with variable and the use of electric power on this after selecting main variables that can influence to the energy of the train operation in the software aspect. First, after collecting the basic data related to operation(train speed, operating hours, power consumption, the position of stopping station, electrical power system etc.) and according to this, investigating the consumption of the energy of the operation, in the side of energy consumption deducing and analyzing problem, this will be found solutions.

• Journal of architectural history
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• v.25 no.6
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• pp.7-16
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• 2016

The purpose of this study is to find framework schema of early J usimpo-style Buddhist halls (Geungnakjeon Hall of Bongjeongsa Temple, Muryangsujeon Hall of Buseoksa Temple, and Daeungjeon Hall of Sudeoksa Temple). Though the halls are known as built in the late Goryeo Period, they show the influence of the architectural style of the early Unified Silla Period. To find the adopted modules and proportions of these halls, this study conceived a schematic diagram based on the whole frame structure taking reference from the Cai-Fen system in Yingzao Fashi. In these three halls, the heights of each cross-beam (Dori) are made up by the layers of member and member units. This study computes the values of Cai, Zhi, and Fen which can apply to both the section and the plan. The vertical section structure is determined by combining the standard member heights (Cai) and the standard unit heights (CaiZhi). The bays of columns are made by multiples of the standard member width (Fen).

• Journal of Korean Academy of Nursing
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• v.34 no.1
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• pp.81-92
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• 2004

Purpose: The purpose of this study was to identify a path diagram for the influence of family, personality, sexual abuse, drug abuse, coping strategies, and aggressive impulsiveness on aggression, and to develop a sublimation program for Korean adolescent's aggression. Method: Data was collected by self-report questionnaires. Subjects consisted of 2,111 adolescents. A proportional stratified random sampling method was used. The major instrument was the Mental Health Questionnaire for Korean Adolescents, and the Cronbach's Alpha ranged from .54 to .95 for each subscale. Statistical methods were Chi-square, correlation analysis, and path analysis. Results: The strongest contributing variables on aggression were person-related aggressive impulsiveness, antisocial personality, self-injured aggressive impulsiveness, gender, sexual abuse, psychosomatic symptoms II, drug abuse, age, parent-child relationship, alcohol abuse and cognitive avoidance coping strategies in the order named. Also the author developed a multi-systemic sublimation program for Korean adolescents's aggression. The multi-systemic sublimation program involves four domains including adolescents, parents, peers and community, and has several therapeutic sub-programs for each domain. Conclusion: The ecology of human development is composed of multiple, integrated levels of organization, including biological, individual-psychological, social-interpersonal, cultural, and historical levels. Therefore, this multi-systemic sublimation program will prevent and decrease the rate of aggressive behavior among Korean adolescents.

• Computers and Concrete
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• v.15 no.4
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• pp.643-671
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• 2015

Chloride induced reinforcement corrosion is widely accepted to be the most frequent mechanism causing premature degradation of reinforced concrete members, whose economic and social consequences are growing up continuously. Prevention of these phenomena has a great importance in structural design, and modern Codes and Standards impose prescriptions concerning design details and concrete mix proportion for structures exposed to different external aggressive conditions, grouped in environmental classes. This paper focuses on reinforced concrete column section load carrying capacity degradation over time due to chloride induced steel pitting corrosion. The structural element is considered to be exposed to marine environment and the effects of corrosion are described by the time degradation of the axial-bending interaction diagram. Because chlorides ingress and consequent pitting corrosion propagation are both time-dependent mechanisms, the study adopts a time-variant predictive approach to evaluate residual strength of corroded reinforced concrete columns at different lifetimes. Corrosion initiation and propagation process is modelled by taking into account all the parameters, such as external environmental conditions, concrete mix proportion, concrete cover and so on, which influence the time evolution of the corrosion phenomenon and its effects on the residual strength of reinforced concrete columns sections.

• Textile Coloration and Finishing
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• v.8 no.5
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• pp.68-75
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• 1996

Even if fibers are practically identical with respect to chemical composition and denier, the dyeabilities are freqently a little different in an industrial processing. It is difficult to interpret the numerical values of dye diffusion coefficients from a dye solution into fibers. The main reasons are the multicomponent nature of the diffusion process and the inhomogeneities of the substrate, so-called, various kinds of ordered and disordered regions of polymers, void and pores. The equilibrium dye adsorptions and dyeing rates of a disperse dye into the several PET fibers having the same denier were determined at various temperatures. The dyeability of examined samples was divided into two groups, that is, lower dye adsorption fiber and higher ones at the lower temperatures. This result was discussed with the degree of crystallinity, DSC diagram, X-ray diffractometry and Porosimetry of the PET fiber, and an appropriate model for fine structure of PET fiber was proposed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.42-43
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• 2019

In-situ production of PC (precast concrete) members can reduce costs by about 14.5% -21.6% compared to in-plant production due to the reduction of transportation costs, factory profits and overhead costs. However, in-situ production of PC members presents a variety of risks, including member production and yard area securing, and lead time for production within the installation period. To solve this, it is necessary be able to analyze and control and monitor the risk factors that influence in-situ production for PC member. The purpose of this study is to develop a dynamic simulation model for in-situ production and erection integrated management for PC members. For this study, risk factor identification, causal loop diagram, and dynamic simulation model construction were performed sequentially. The results of this study will be used as a basis for developing a risk management model for PC in-situ production.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.75.1-75.1
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• 2019

The universe has been ionized in the post-reionization by several photon contributors. The dominant source to produce the hydrogen ionizing photons is not revealed so far. Faint quasars have been expected to generate UV photon budgets required to maintain ionization state of universe. Observational limits, however, hinder to discover them despite their higher number density than bright one. Consequently, the influence of faint quasars on post-reionization are not considered sufficiently. Therefore, a survey to find faint quasars at z ~ 5 is crucial to determine the main ionizing source in the post-reionization era. Deep images from the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP) allow us to search for quasar swith low luminosities in the ELAIS-N1 field. J band information are obtained by the Infrared Medium-deep Survey (IMS) and the UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep ExtragalacticSurvey (DXS). Faint quasar candidates were selected from several multi-band color cut criteria based on simulated quasars on color-color diagram. To choose the reliable candidates with possible Lyman break, we have performed medium-bands observations. Whether a candidate is a quasar or a dwarf star contamination was decided by results from chi-square minimization of quasar/dwarf model fitting. Spectroscopic follow-up observations confirm three quasars at z ~ 5. 100% spectral confirmation success rate implies that the medium-band observations effectively select faint quasars with strong Lyman alpha emission.

• Advances in concrete construction
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• v.11 no.3
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• pp.261-270
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• 2021

In this study, a new understanding is presented on the microcracking behavior of high strength concrete (HSC) with steel fiber addition having prior compressive loading history. Microcracking behavior at critical stress (σcr) region, using seven fiber addition volume of 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, and 2.0% was evaluated, at two aspect ratios (60 and 75). The specimens were loaded up to a specified compressive stress levels (0.70fc-0.96fc), and subsequently subjected to split tensile tests. This was followed by microscopic analyses afterwards. Four compressive stress levels as percentage of fc were selected according to the linearity end point based on stress-time (σ-t) diagram under uniaxial compression. It was seen that pre-compression has an effect on the linearity end point as well as fiber addition where it lies within 85-91% of fc. Tensile strength gain was observed in some cases with respect to the 'maiden' tensile strength as oppose to tensile strength loss due to the fiber addition with teething effect. Aggregate cracking was the dominant failure mode instead of bond cracks due to improved matrix quality. The presence of the steel fiber improved the extensive failure pattern of cracks where it changes from 'macrocracks' to a branched network of microcracks especially at higher fiber dosages. The applied pre-compression resulted in hardening effect, but the cracking process is similar to that in concrete without fiber addition.

• Advances in Computational Design
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• v.7 no.3
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• pp.253-279
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• 2022

This study investigated and predicted the Marshall stability of glass-fiber asphalt mix, carbon-fiber asphalt mix and glass-carbon-fiber asphalt (hybrid) mix by using machine learning techniques such as Artificial Neural Network (ANN), Support Vector Machine (SVM) and Random Forest(RF), The data was obtained from the experiments and the research articles. Assessment of results indicated that performance of the Artificial Neural Network (ANN) based model outperformed applied models in training and testing datasets with values of indices as; coefficient of correlation (CC) 0.8492 and 0.8234, mean absolute error (MAE) 2.0999 and 2.5408, root mean squared error (RMSE) 2.8541 and 3.3165, relative absolute error (RAE) 48.16% and 54.05%, relative squared error (RRSE) 53.14% and 57.39%, Willmott's index (WI) 0.7490 and 0.7011, Scattering index (SI) 0.4134 and 0.3702 and BIAS 0.3020 and 0.4300 for both training and testing stages respectively. The Taylor diagram also confirms that the ANN-based model outperforms the other models. Results of sensitivity analysis show that Carbon fiber has a major influence in predicting the Marshall stability. However, the carbon fiber (CF) followed by glass-carbon fiber (50GF:50CF) and the optimal combination CF + (50GF:50CF) are found to be most sensitive in predicting the Marshall stability of fibrous asphalt concrete.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1851-1859
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• 2022

Experimental research on flow characteristics of open natural circulation system was performed, to figure out the mechanism of the open natural circulation behaviors. The influence factors, such as the heating power, the inlet subcooled and the level of cooling tank on the flow characteristics of the system were examined. It was shown that within the scope of the experimental conditions, there are five flow types: single-phase stable flow, flash and geyser coexisting unstable flow, flash stable flow, flash unstable flow, and flash and boiling coexisting unstable flow. The geyser flow in flash and geyser coexisting unstable flow is different from classic geysers flow. The flow oscillation period and amplitude of the former are more regular, is a newly discovered flow pattern. By drawing the flow instability boundary diagram and sorting out the flow types, it is found that the two-phase unstable flow is mainly characterized by boiling and flash, which determine the behavior of open natural circulation respectively or jointly. Moreover, compared with full liquid level system, non-full liquid level system is more prone to boiling phenomenon, and the range of heat flux density and undercooling degree corresponding to unstable flow is larger.