• Journal of the Korean Geosynthetics Society
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• v.3 no.4
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• pp.3-12
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• 2004

In this paper, a mechanism of the soil structure reinforced by geosynthetics is discussed. The reinforcing mechanism is interpreted an effect arising from the reinforcement works so as to prevent the dilative deformation (negative dilatancy) of soil under shearing. A full-scale in-situ model test was carried out in Kanazawa of Japan(1994) and in the laboratory test the strength and the characteristics of deformation conducting a constant volume shear test are examined. The parameters needed in the FEM are also applied by using the experimental data. The elasto-plastic finite element simulation is carried out, and the results are quantitatively compared with that of experiment. As a results, it is known that the theoretical predictions could be explained effectively the experimental results which are obtained by a full-scale in-situ model test.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.59-65
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• 2008

Nowadays, implantable hearing aids have been developed to solve the problems of conventional hearing aids. In case of fully implantable hearing aids, an implantable microphone is necessary to receive sound signal beneath the skin. Normally, an implantable microphone has poor frequency response characteristics in high frequency bands of acoustic signal due to the high frequency attenuation effect of skin after implantation to human body. In this paper, the implantable microphone is designed to reduce the high frequency attenuation effect of a skin by putting its resonance frequency at the attenuated range through a finite element analysis (FEA) simulation. The designed implantable microphone through the simulated results has been fabricated by manufacturing process using bio-compatible materials. By the several in-vitro experiments with pig skin, it has been verified that the designed implantable microphone has a resonance frequency around the starting part of the attenuated range and reduces the attenuation effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1532-1538
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• 2011

In this study, we investigate the cracks that formed on the upper floor of the structures due to continuous dynamic loading. We explain the cause of floor slab cracks on the upper floor of the distribution center and discuss preventive measures that can enhance the center's functions and security. In order to explain how a forklift's excessive vibration can cause the cracks, we have measured and analyzed the vibration during a forklift's operation and discovered that the cracks form because the vibration exceeds the vibration criteria. Using a finite element modeling on such results, we have come up with optimal methods to reduce the vibration and confirmed their validity by measuring the vibration after implementing our methods.

• Journal of the Korea Society for Simulation
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• v.29 no.3
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• pp.73-82
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• 2020

In the fourth industrial revolution, wireless sensor networks (WSNs) are an important element of collecting and analyzing data in a variety of environments without human intervention. This sensor network is greatly affected by topology and routing protocols. Routing protocols, which affect energy consumption, are executed after deploying sensor nodes. Once built, they are difficult to change. Before the WSN is deployed, a routing protocol is carefully selected in view of various environments and the performance of the protocol is evaluated. In this paper, we propose a model to simulate multiple routing protocols using a discrete event system specification (DEVS). The DEVS-based proposed model simulates various situations without changes and structures of the its model as algorithms of the routing protocols are implemented in its coordinators model. To verify normal behaviors of the proposed model, the number of report delivery and the energy consumption of the sensor network were compared using representative protocols LEACH and Dijkstra. As a result, it was confirmed that the proposed model executes normally in both routing protocols.

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.61-69
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• 2019

Recently, as a new ICT trend, emerging chatbots are actively introduced in the field of finance. Chatbot conducts services through the interaction of communication with users. The purpose of this study is to investigate the effect of interaction dialogue type on the efficiency, usability, sensibility and perceived security of financial service chatbot. Based on theoretical considerations, I have divided into closed conversation, open conversation, and mixed conversation type based on the conversation style based on the implementation method of chatbot. Three types of Financial Chatbot prototypes were made and the experiments were conducted after account inquiry, account transfer, Q & A financial task execution. As a result of experimental research analysis, chatbot's interaction dialogue type was found to affect efficiency and usability. Users have shown that the interaction of closed conversations and mixed conversations is an intuitive interface that allows financial services to be easily manipulated without error. This study will be used as a resource to improve the user experience that requires deep understanding of financial chatbot users who should consider both the emotional element of artificial intelligence that provides services through natural conversation and the functional elements that perform financial business can be.

• The Southeast Asian review
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• v.20 no.2
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• pp.135-178
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• 2010

This study is to seek alternatives for regional governance related to transnational labor migration issues in Southeast Asia. This study examined the present situation and trends of labor migration in the region, reviewed involved transnational issues, and identified the current issues of governance to seek alternatives for regional governance. The increase in cross-border labor migration is no doubt a sign of growth and dynamism of the region and greater integration of their economies. But it also poses complex policy and management issues as well as transnational issues over such as unequal economic profits, illegal migration, human rights, and social security issues. In this reality, regional governance is a very important theme and the efforts to manage their migration inherently involve fundamental conflict and tension between related countries and regions. However, politics and governance of transnational migrant workers in Southeast Asia are still pursued at the national level. To resolve these issues, it is urgently required to secure not only collaboration between the parties concerned but also governance at the regional level. Findings of this study are: First, although labor migration has been a relatively long-time transnational issue, the history of addressing the issue at the regional governance is very short and still inceptive. Second, given its size, labor migration in Southeast Asia requires effective regional governance but no breakthrough was possible due to the conflict of interests between origin and destination countries and the conflict of logic between the labor market and the state. Third, the issue of labor migration is an important element for the formation of economic and socio-cultural communities the ASEAN countries have pursued. Fourth, it is urgently needed to seek alternatives for good and effective regional governance as a key to resolving these issues over migrant workers in Southeast Asia.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.115-124
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• 2021

The outbreak of covid-19 has brought the characteristics and advantages of non-contact services to increased prominence, and the development of smart hotels"has accelerated. This study aims to identify, categorize and define the smart service experience at different touch points of the customer experience. The concept and characteristics of the smart hotel were examined based on existing research and literature. An analytical framework was designed using smart experience factors and customer touch points of smart hotels. Selected Chinese smart hotels were then examined under this framework. The case analysis results show that the customer experience design of smart hotels has developed to different degrees, in terms of interactivity, personalization, accessibility, information and privacy security. Based on the above findings, this article suggests that the design of smart hotels should use integrated data to further enhance personalized service experience.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.279-285
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• 2021

The materials, parts, and equipment industries are the backbone of the manufacturing industry and a key element of competitiveness. However, in the case of Korea, as it relies on foreign countries for core materials, parts, and equipment, it is in danger of not only industrial competitiveness, but also security. This study first looked at the outline and current address of the materials, parts, and equipment industries, identified problems and improvements, and examined the efforts and achievements so far for the localization of materials, parts, and equipment in Korea. In addition, after looking at the improvement measures for the government's material, parts, and equipment industry at the institutional level or at the ecological level, the current status and actual condition of localization of local materials, parts and equipment were investigated, and problems and improvements were analyzed. Lastly, this study presented a technology development plan for localization of parts and materials in the region and various institutional improvement plans related to commercialization.

• Structural Engineering and Mechanics
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• v.81 no.6
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• pp.665-675
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• 2022

The safety problems of giant hydraulic structures such as dams caused by terrorist attacks, earthquakes, and wars often have an important impact on a country's economy and people's livelihood. For the national defense department, timely and effective assessment of damage to or impending damage to dams and other structures is an important issue related to the safety of people's lives and property. In the field of damage assessment and vulnerability analysis, it is usually necessary to give the damage assessment results within a few minutes to determine the physical damage (crack length, crater size, etc.) and functional damage (decreased power generation capacity, dam stability descent, etc.), so that other defense and security departments can take corresponding measures to control potential other hazards. Although traditional numerical calculation methods can accurately calculate the crack length and crater size under certain combat conditions, it usually takes a long time and is not suitable for rapid damage assessment. In order to solve similar problems, this article combines simulation calculation methods with machine learning technology interdisciplinary. First, the common concrete gravity dam shape was selected as the simulation calculation object, and XFEM (Extended Finite Element Method) was used to simulate and calculate 19 cracks with different initial positions. Then, an LSTM (Long-Short Term Memory) machine learning model was established. 15 crack paths were selected as the training set and others were set for test. At last, the LSTM model was trained by the training set, and the prediction results on the crack path were compared with the test set. The results show that this method can be used to predict the crack propagation path rapidly and accurately. In general, this article explores the application of machine learning related technologies in the field of mechanics. It has broad application prospects in the fields of damage assessment and vulnerability analysis.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.71-81
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• 2021

This paper examines the ongoing research on ways to improve cybersecurity during the entire life cycle of weapons systems applied in advanced countries such as the United States, analyzes restrictions on obtaining domestic weapons systems, and presents effective security evaluation measures. By consistently performing mission-based risk assessment in the cybersecurity test and evaluation plan suitable for domestic circumstances at all stages of acquisition, important information is provided to major decision-making organizations in a timely manner to support decision-making, and to respond to identified vulnerabilities in cybersecurity. It is proposed to set the rules of engagement so that the protection measures can be verified, and a simulated invasion is proposed. In addition, the proposed cybersecurity test and evaluation system was compared with the domestic weapon system test and evaluation. Through this, the mission-based risk assessment element was grafted into the cybersecurity test and evaluation system research conducted so far to identify risks in a timely manner between acquisition projects, thereby supplementing the capability to support major decision-making.