• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.158-160
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• 2022

Many office workers spend a lot of time performing repetitive office tasks in inefficient ways. We developed a user-friendly chatbot system based on Kakaotalk to automate repetitive tasks and used the chatbot in the real workplace. In the process of operating the chatbot, if several people use the chatbot at the same time, the server was down or could not respond. To address these issues, we performed code migration of programs used by chatbot back-end servers and tried several ways to improve server performance such as database redesign and load balancing. To determine how much each method affects performance improvement, we measured total request per second and average latency. After that, we proposed ways to improve the problems of using the chatbot in the work environment.

• International Journal of High-Rise Buildings
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• v.12 no.2
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• pp.179-193
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• 2023

It is undeniable that urban greenspace is the soul of a city. Conventional urban greenspace such as parks, community gardens, playgrounds etc. located within a city reduce the negative effects of pollution, play a major role in the survival of the urban ecosystem, and promote healthy lifestyles. Today, 55% of the world's population lives in urban areas, which is expected to increase to 68% by 2050. Projections show that urbanization and the gradual migration to urban areas combined with the fast growth of the world's population, could add another 2.5 billion people to urban areas by 2050 and almost 90% of this increase will take place in Asia(UN, 2018). As a result, many plots in the cities are and will continue to be occupied with buildings to provide residential support to the increased population. This will dangerously decrease urban greenspaces. Moreover, worldwide, food crisis, energy crisis, and social crisis is posing a great threat to the existence of mankind. Additionally, the COVID - 19 has introduced a new lifestyle where from work culture to community configuration has drastically transformed. In this scenario, residential buildings will have to serve more than just providing privacy and shelter. As urban greenspaces are being occupied by concrete residential buildings, these buildings will have to compensate for the percentage of urban green they are destroying and the issues they are imposing in the process. The goal of this thesis is to design, architecturally define and, categorize comprehensive 'sustainable Greenspace'(S.G.S) for the multi-family housing scenario. These will be different than the conventional green (veranda, rooftop green) we commonly see in residential buildings. An old, dilapidated apartment building will be the target of remodeling to fulfill the purpose of this thesis.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.644-651
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• 2011

Storing hydrogen in solid state hydride is one of the best promising methods for the future hydrogen economy. The total performance of such systems depends on the rate at which the amount of mass and heat migration is supplied to solid hydride. Therefore, an accurate modeling of the heat and mass transfer is of prime importance in optimizing the design of such systems. In this work, Hydrogen storage in Pt-CNTs hydrogen reactor has been intensively investigated by solving 2 dimensional mathematical models. Using a CFD computer software, systematic studies have been performed to elucidate the effect of heat and mass transfer during hydrogen charging periods. It was revealed that the optimized design of hydrogen storage vessel can prevent the increase of system temperature and the charging time due to the convective cooling effects inside the vessels at even high charging pressure. Because none has reported the critical issues of heat and mass transfer for CNT based hydrogen storage system, this work can support the first insight of the optimal design for solid state hydrogen storage system based on CNT in the near future.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.49-55
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• 2009

This paper describes a three-dimensional ground penetrating radar (GPR) survey carried out around a levee of the Ara River in Saitama, Japan, where deformation of the ground was observed after heavy rainfall associated with the typhoon of September 2007. The high-density 3D GPR survey was conducted as a series of closely adjacent four directional sets of 2D surveys at an area surrounding vertical cracks on the paved road caused by deformations induced by heavy rain. The survey directions of the 2D surveys were 0, 90, 45, and -45 degrees with respect to the paved road and the intervals between lines were less than 0.5 m. The 3D subsurface structure was accurately imaged by the result of data processing using Kirchhoff-type 3D migration. As a result, locations and vertical continuities of the heavy rainfall induced cracks in the paved road were clearly imaged. This will be a great help in considering the generation mechanisms of the cracks. Moreover, the current risk of a secondary disaster was found to be low, as no air-filled cavities were detected by the 3D GPR survey.

• Nuclear Engineering and Technology
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• v.47 no.5
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• pp.608-616
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• 2015

The migration of silver (Ag) in silicon carbide (SiC) and $^{110m}Ag$ through SiC of irradiated tristructural isotropic (TRISO) fuel has been studied for the past three to four decades. However, there is no satisfactory explanation for the transport mechanism of Ag in SiC. In this work, the diffusion coefficients of Ag measured and/or estimated in previous studies were reviewed, and then pre-exponential factors and activation energies from the previous experiments were evaluated using Arrhenius equation. The activation energy is $247.4kJ{\cdot}mol^{-1}$ from Ag paste experiments between two SiC layers produced using fluidized-bed chemical vapor deposition (FBCVD), $125.3kJ{\cdot}mol^{-1}$ from integral release experiments (annealing of irradiated TRISO fuel), $121.8kJ{\cdot}mol^{-1}$ from fractional Ag release during irradiation of TRISO fuel in high flux reactor (HFR), and $274.8kJ{\cdot}mol^{-1}$ from Ag ion implantation experiments, respectively. The activation energy from ion implantation experiments is greater than that from Ag paste, fractional release and integral release, and the activation energy from Ag paste experiments is approximately two times greater than that from integral release experiments and fractional Ag release during the irradiation of TRISO fuel in HFR. The pre-exponential factors are also very different depending on the experimental methods and estimation. From a comparison of the pre-exponential factors and activation energies, it can be analogized that the diffusion mechanism of Ag using ion implantation experiment is different from other experiments, such as a Ag paste experiment, integral release experiments, and heating experiments after irradiating TRISO fuel in HFR. However, the results of this work do not support the long held assumption that Ag release from FBCVD-SiC, used for the coating layer in TRISO fuel, is dominated by grain boundary diffusion. In order to understand in detail the transport mechanism of Ag through the coating layer, FBCVD-SiC in TRISO fuel, a microstructural change caused by neutron irradiation during operation has to be fully considered.

• Journal of Korean Society of Archives and Records Management
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• v.16 no.2
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• pp.143-172
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• 2016

This study analyzes the process of growth of Busan from a fishing village to the capital city of South Gyeongsang Province and the central city of transportation and commerce, and an industry with records. The results of the analysis are as follows: after the port opened in 1876, there has been a decline in settlement spaces in Dongnae; on the other hand, there has been an increase in migration spaces around the port of Busan. Waegwan (倭館) nearby Yongdusan Mountain (龍頭山) was changed to the Japanese concession; thus, the number of Japanese moving into Busan had rapidly increased. As a result, the Japanese government carried out reclamation work for securing available lands for the construction of port facilities and other facilities. The Japanese government built public offices and houses, as well as production facilities for daily necessities around the port of Busan. The opening of the Seoul Busan railway (京釜線) and the cross-channel liner between Busan and Shimonoseki (釜關連絡船) led to the growth of Busan and the development of its status. At this time, as the main industry of Busan was trade, Busan had grown as a commercial city. As Busan had grown as a central city of transportation and commerce, the provincial government building of Gyeongsangnam-do (慶尙南道) moved to Busan. Thus, Busan became the central city of local politics and administration. After the Land Survey Project, a large scale of farmers were recruited for low-wage work in the new port. Because of the abolition of the corporation law, Japanese capitalists moved into their colony in Busan. There, large-scale factories, such as the Joseon cotton textile factory, were established. Through this process, the locality of Busan was changed from a fishing village to a commercial city and, finally, to a city of commerce and industry.

• Korea journal of population studies
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• v.31 no.3
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• pp.131-157
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• 2008

The purpose of this study was to examine the difference in depression level of Japanese, Chinese and Vietnamese wives who are residing in Korean society. Special focus was taken to compare the differences in terms of the origin of nationality. Guided by the role theory, we analyzed the effect of parental role and work role on depression of foreign wives. Also we considered the social resources, ethnic characteristic that are well-known to be associated with the role performance, in this study. The data came from the sample of 524 foreign wives case (Japanese 35%, Chinese 31%, Vietnamese 34%). The result show us that depression level is different by origin of nationality of foreign wives: Vietnamese wives were more depressed compare to Japanese or Chinese wives. The effects of two social role on depression were significant even if the social resources and ethnicity are considered in the model. However, the strength of the effect of social roles were different by one another: having a job was especially effective to decrease the Chinese wife's depression level, while for the Vietnamese wives, parental role was essential to lower the depression level. In addition, the social determinants of depression were differ by the nationalities of wives. The results imply that the social adaptation process of foreign wife may be varied by the origin of nationality.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.345-353
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• 2021

Cloud computing represent a new era of computing that's forms through the combination of service-oriented architecture (SOA), Internet and grid computing with virtualization technology. Virtualization is a concept through which every cloud is enable to provide on-demand services to the users. Most IT service provider adopt cloud based services for their users to meet the high demand of computation, as it is most flexible, reliable and scalable technology. Energy based performance tradeoff become the main challenge in cloud computing, as its acceptance and popularity increases day by day. Cloud data centers required a huge amount of power supply to the virtualization of servers for maintain on- demand high computing. High power demand increase the energy cost of service providers as well as it also harm the environment through the emission of CO₂. An optimization of cloud computing based on energy-performance tradeoff is required to obtain the balance between energy saving and QoS (quality of services) policies of cloud. A study about power usage of resources in cloud data centers based on workload assign to them, says that an idle server consume near about 50% of its peak utilization power [1]. Therefore, more number of underutilized servers in any cloud data center is responsible to reduce the energy performance tradeoff. To handle this issue, a lots of research proposed as energy efficient algorithms for minimize the consumption of energy and also maintain the SLA (service level agreement) at a satisfactory level. VM (virtual machine) consolidation is one such technique that ensured about the balance of energy based SLA. In the scope of this paper, we explore reinforcement with fuzzy logic (RFL) for VM consolidation to achieve energy based SLA. In this proposed RFL based active VM consolidation, the primary objective is to manage physical server (PS) nodes in order to avoid over-utilized and under-utilized, and to optimize the placement of VMs. A dynamic threshold (based on RFL) is proposed for over-utilized PS detection. For over-utilized PS, a VM selection policy based on fuzzy logic is proposed, which selects VM for migration to maintain the balance of SLA. Additionally, it incorporate VM placement policy through categorization of non-overutilized servers as- balanced, under-utilized and critical. CloudSim toolkit is used to simulate the proposed work on real-world work load traces of CoMon Project define by PlanetLab. Simulation results shows that the proposed policies is most energy efficient compared to others in terms of reduction in both electricity usage and SLA violation.

• Women's Studies Review
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• v.26 no.1
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• pp.183-206
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• 2009

This study attempts to explore a phenomenon of an expansion of emotional capitalism in the context of marriage migration. Emphasizing that 'emotion,' 'love,' 'affection,' 'intimacy,' and 'care' are neither materialistic nor a work, and noting that they are social roles attached to natural femininity and that they are separated from the economic realm, modern myth has been challenged by the increase of marriage industry, emotional/service work, and care industry. This study discusses the ways in which individual desires for love and intimacy and her/his economical needs are combined or negotiated. Specifically, this study 1) reviews existing literature on how 'love' and 'intimacy' has been combined with economy under capitalism in general, 2) discusses the ways in which a marriage has been commercially negotiated within the context of South Korea, 3) analyzes combined aspects of 'love' and 'economy' within cross-border marriages and suggests that cross-border marriages, even though they are highly commercially negotiated, may not be fully explained by 'economy' only as other marriages have both aspects of 'love' and 'economy.' An analysis on 'love' and 'economy,' not only separated from each other but also controversial, is essential for understanding 'intimacy' and transitions of Korean families in post-modern era. However, the evaluation criteria for commercial trades in 'love' and 'intimacy' have not developed yet. Whereas a certain trade is inevitable or essential, others may threaten our lives. Developing the ethical and political evaluation criteria on such commercial trades requires future study.

• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.481-490
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• 2012

Evaluation of chloride penetration is very important, because induced chloride ion causes corrosion in embedded steel. Diffusion coefficient obtained from rapid chloride penetration test is currently used, however this method cannot provide a correct prediction of chloride content since it shows only ion migration velocity in electrical field. Apparent diffusion coefficient of chloride ion based on simple Fick's Law can provide a total chloride penetration magnitude to engineers. This study proposes an analysis technique to predict chloride penetration using apparent diffusion coefficient of chloride ion from neural network (NN) algorithm and time-dependent diffusion phenomena. For this work, thirty mix proportions with the related diffusion coefficients are studied. The components of mix proportions such as w/b ratio, unit content of cement, slag, fly ash, silica fume, and fine/coarse aggregate are selected as neurons, then learning for apparent diffusion coefficient is trained. Considering time-dependent diffusion coefficient based on Fick's Law, the technique for chloride penetration analysis is proposed. The applicability of the technique is verified through test results from short, long term submerged test, and field investigations. The proposed technique can be improved through NN learning-training based on the acquisition of various mix proportions and the related diffusion coefficients of chloride ion.