• Steel and Composite Structures
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• v.47 no.2
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• pp.167-184
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• 2023

In this study, a new recentering friction device (RFD) to retrofit steel moment frame structures is introduced. The device provides both self-centering and energy dissipation capabilities for the retrofitted structure. A hybrid performance-based seismic design procedure considering multiple limit states is proposed for designing the device and the retrofitted structure. The design of the RFD is achieved by modifying the conventional performance-based seismic design (PBSD) procedure using computational intelligence techniques, namely, genetic algorithm (GA) and artificial neural network (ANN). Numerous nonlinear time-history response analyses (NLTHAs) are conducted on multi-degree of freedom (MDOF) and single-degree of freedom (SDOF) systems to train and validate the ANN to achieve high prediction accuracy. The proposed procedure and the new RFD are assessed using 2D and 3D models globally and locally. Globally, the effectiveness of the proposed device is assessed by conducting NLTHAs to check the maximum inter-story drift ratio (MIDR). Seismic fragilities of the retrofitted models are investigated by constructing fragility curves of the models for different limit states. After that, seismic life cycle cost (LCC) is estimated for the models with and without the retrofit. Locally, the stress concentration at the contact point of the RFD and the existing steel frame is checked being within acceptable limits using finite element modeling (FEM). The RFD showed its effectiveness in minimizing MIDR and eliminating residual drift for low to mid-rise steel frames models tested. GA and ANN proved to be crucial integrated parts in the modified PBSD to achieve the required seismic performance at different limit states with reasonable computational cost. ANN showed a very high prediction accuracy for transformation between MDOF and SDOF systems. Also, the proposed retrofit showed its efficiency in enhancing the seismic fragility and reducing the LCC significantly compared to the un-retrofitted models.

• Spatial Information Research
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• v.23 no.2
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• pp.83-93
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• 2015

U-Services, which are offered from local governments based on their Ubiquitous City Plans, are only focused on facility and urban management services. Also Citizen oriented U-service is only planned. This study's purpose is to propose the implication for provide of the Citizen oriented U-service comparing with U-Service plan of 'Ubiquitous City Comprehensive Plan' and 'Ubiquitous City Plan' through a network text analysis and word frequency analysis. It was calculated a important keyword that was extracted the service plan contents of the 'Ubiquitous City Comprehensive Plan' and 'Ubiquitous City Plan' of the four local governments. The network text analysis and keyword frequency analysis was performed through derived keyword. Based on the analysis results, awareness of the citizens can be expected to increase about U-City by activating a excavation of Citizen oriented U-service in a variety of sector through additional services and policy of financial support in the next Ubiquitous City Comprehensive Plan.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.41-42
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• 2015

도시에서의 에너지는 주로 인력에 의해 관리되고 소비된다. 전력이나 물, 가스 등 살아가는데 필요한 에너지는 화석연료로 생산되거나 만들어진다. 따라서 전력 등과 같은 에너지의 소비가 많을수록 이산화탄소 배출이나 지구온난화가 심화된다. 도시의 건축물에 대한 에너지의 공급체계는 건축물과 별도로 구성되어 있어 통합적 관리를 통해 사용량을 최적화하여야 한다. 본 논문에서는 스마트그리드 스테이션을 기반으로 한 스마트그리드 시티를 구축하는 방안을 제시하고자 한다. 이를 통해 홈, 타운, 시티를 거쳐 최종적으로 스마트 에너지 국가를 완성하게 된다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.989-995
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• 2009

Smart Dining Table is an ongoing project in our Interaction Design Lab. It is a table top display designed to facilitate dining process. Smart Dining Table uses touchable interface to interact with users, providing a new, interesting and efficient experience in dining process. In GuangZhou, the south city of China, Yam Cha is a traditional and local way of entertainment in which normally elders gather together with friends or relatives to have tea and snack, and most importantly, to chat. Yam Cha has a long history in China, and Guangzhou has developed its own unique "Yam Cha" culture. In this paper, we discuss about previous research we did on Yam Cha in GuangZhou, and the approach we propose to manage and analyze issues related to dining table to help designing specific version of Smart Dining Table which can fit right into the Yam Cha process and cultural environment.

• Journal of Information Processing Systems
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• v.16 no.1
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• pp.1-5
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• 2020

Sustainable computing is a rapidly expanding field of research covering the fields of multidisciplinary engineering. With the rapid adoption of Internet of Things (IoT) devices, issues such as security, privacy, efficiency, and green computing infrastructure are increasing day by day. To achieve a sustainable computing ecosystem for future smart cities, it is important to take into account their entire life cycle from design and manufacturing to recycling and disposal as well as their wider impact on humans and the places around them. The energy efficiency aspects of the computing system range from electronic circuits to applications for systems covering small IoT devices up to large data centers. This editorial focuses on the security, privacy, and efficiency of sustainable computing for future smart cities. This issue accepted 17 articles after a rigorous review process.

• International Journal of High-Rise Buildings
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• v.9 no.1
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• pp.81-85
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• 2020

Currently, urban mobility is rather two-dimensional: Connections between transportation solutions like elevators, escalators, moving walks, and metro stations are static. In the future, urban mobility will require a holistic view: Seamless transportation, enabled by innovative IoT technology, is a necessity. A dialogue between the city, its buildings and transportation systems, considering the specific needs and preferences of each and every citizen, must be adopted. Travelling through the city will become a lot more individualized, interactive and customized to specific requirements.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1485-1488
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• 2010

기업들의 글로벌화가 빠르게 진행되고 고객 밀착형 업무가 늘어나게 됨에 따라 모바일 오피스에 대한 기업의 니즈가 빠르게 증가했다. 이러한 비즈니스 요건을 해결하기 위해서는 기업 근무자가 다른 시간, 다른 장소에서도 효과적인 업무 협업과 커뮤니케이션을 수행할 수 있는 서비스와 시스템 환경이 필요하다. 실시간 비즈니스 협업 시스템은 기업 근무자들이 스마트 폰과 웹을 통해서 실시간으로 업무 협업을 할 수 있도록 상호 서비스 호출이 가능한 시스템을 구현 하였다.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.13-25
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• 2017

The Korean government is pursuing technological development through nearly every government agency, and Korea's growing R&D spending is yielding good results in many fields. With the country moving from the technology development stage to the demonstration stage, it is actively implementing testbed projects to demonstrate developed technologies and services. This is, however, not without problems. There is no consistent systematic system for the testbed projects because government agencies compete against each other in the planning of execution of R&D: they do not work together. The most serious problem is that both testbeds and developed technologies die out due to poor operation management after the completion of test projects. Research should, therefore, be done on operation management and commercialization. However, the government still does not consider the system after the test: it focuses on building testbeds to verify developed technologies. This study intends to determine the basic orientation of operation management to ensure maximum performance, efficiency, and continuity of national projects through intensive analysis of ongoing national R&D testbed projects and examination of success stories of operation management at home and abroad.

• Journal of Wetlands Research
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• v.23 no.3
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• pp.260-276
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• 2021

Wetlands are constantly affected by internal and external environments that make up the wetlands, and these effects make wetlands change. East Asia countries where about 15% of Ramsar's registered wetlands are located, is valuable conservation area due to various wetland types and biodiversity. However, due to climate change and other factors, the total area of wetlands has been reduced and biodiversity have been damaged. To mitigate these problems and to manage wetlands efficiently, it is important to identify the factors that change wetlands and to identify how each factor affects them. In this study, we conducted a wetland-related literature analysis in East Asia to derive factors that affect the changes in wetlands, and analyzed the relationships among the factors. Finally we presented research directions considering wetland change factors. In most of the East Asia countries, it was found that there is deficiency in research studies about extraction in direct factors and water-energy infrastructure, tourism & recreation in indirect factors. Also, we presented the necessity for future research using the result between connectivity & relationship analysis and indirect drivers of change and their influence on direct drivers of change. The results of this study could contribute to the establishment of an R&D cooperation system in East Asia region and strengthen wetland management.

• Journal of Wetlands Research
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• v.25 no.1
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• pp.64-73
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• 2023

Before 2022, there was a lot of confusion in the process of planning and implementing the projects for ecological restoration of the stream due to dualization the principal agent of stream management. Because the Ministry of Environment took charge of the project in 2022, securing the health of aquatic ecosystem of stream became an essential factor in the project. Therefore, in this study, the streams that require the project for ecological restoration was selected in Han River estuary, where it is essential to secure the health of the stream aquatic ecosystem as blackish water zone and Ramsar wetland are located. Physical, chemical, spatial/humanistic, health of aquatic ecosystems evaluation indexes were calculated based on the detailed facts and figures of the project for ecological restoration of the stream in the beginning. Ranking, re-scaling, z-score, and t-score normalization methods were applied to the calculated evaluation index, and the values were compared and analyzed. After that, the entropy weight method was applied to each evaluation index. Through this process, the streams(Mokgamcheon, Anyangcheon etc.) that require the project for ecological restoration were selected for the purpose of securing the health of the aquatic ecosystem in Han River estuary. The result of this study can be used as basic research data in the process of selecting the priority determination of the projects for ecological restoration of the stream.