• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.3921-3944
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• 2015

Currently Energy-Saving (ES) methods in cellular networks could be improved, as compensation method for irregular Base Station (BS) deployment is not effective, most regional ES algorithm is complex, and performance decline caused by ES action is not evaluated well. To resolve above issues, a low-complexity energy efficient BS cooperation mechanism for Long Time Evolution (LTE) networks is proposed. The mechanism firstly models the ES optimization problem with coverage, resource, power and Quality of Service (QoS) constraints. To resolve the problem with low complexity, it is decomposed into two sub-problems: BS Mode Determination (BMD) problem and User Association Optimization (UAO) problem. To resolve BMD, regional dynamic multi-stage algorithms with BS cooperation pair taking account of load and geographic topology is analyzed. And then a distributed heuristic algorithm guaranteeing user QoS is adopted to resolve UAO. The mechanism is simulated under four LTE scenarios. Comparing to other algorithms, results show that the mechanism can obtain better energy efficiency with acceptable coverage, throughput, and QoS performance.

• International Journal of High-Rise Buildings
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• v.8 no.2
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• pp.95-100
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• 2019

Whilst most research focuses on the reduction of operative energy use in buildings, the aspect of which (and how many) materials are used is often neglected and poorly explored. However, considering the continuous growth of the global population and the limited availability of resources, it is clear that focusing on operative energy alone is too short-sighted. The tasks lying ahead for architects and engineers cannot be accomplished with conventional methods of construction. With a share of 50-60% of global resource consumption, the building industry has a decisive impact on our environment. If business as usual continues, resources will be significantly depleted in a matter of decades. Therefore, researchers of the University of Stuttgart are investigating the concept of adaptivity as a promising method for saving resources in the built environment. The term adaptivity in the context of building structures was first introduced by Werner Sobek. It describes a method where sensors, actuators and control units are implemented in systems or facades in order to oppose physical impacts in an ideal way. The applicability of this method will be verified on an experimental high-rise building at the University campus in Stuttgart. Thus, this paper describes this innovative research project and depicts the concept of adaptivity in high-rise structures. Furthermore, it gives an overview of potential actuation concepts and the interdisciplinary challenges behind them.

• Progress in Superconductivity and Cryogenics
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• v.24 no.3
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• pp.1-6
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• 2022

The Magnetic Force Control MFC technology is very useful because of its physical treatment process. Especially the Magnetic Separation MS technology is expected to contribute to SDGs 2030, Circular Economy and Carbon neutral 2050 realization. This paper describes the review of the IFMFC activity from 2010.The IFMFC is organized by three local committees of researchers in Japan, China and Korea. The IFMFC aims to exchange the information of the development results using the MFC technology and to educate the young researchers. The forum has been held in every year around three countries. In 2020 and 2021, the forum was organized by Zoom online due to the COVID-19. The 134 presentations were made up to 2020.The breakdown of these presentations are categorized to the environment remediation52%, material resource37% and fundamental research/technology11%. The Super Conducting Magnet SCM development promotes the MFC technologies. There are some impressive backgrounds as to the brilliant SM technology applications for many different magnetism ; SCM development, High Gradient Magnetic Separation HGMS, magnetic seeding method and magneto-Archimedes effect. This paper reviews the IFMFC activity according to those presented presentations.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1106-1113
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• 2022

Cost segregation helps reduce tax liabilities by reclassifying real property to personal property and accelerates tax depreciation of a property. A typical cost segregation study requires much time and high costs. This study proposed a BIM integrated cost segregation process that can be applied to any commercial building project. The proposed BIM-based cost segregation process was verified in a new commercial construction project. It approved that this approach can: (1) increase the cash flow for the owner and provide assistance to tax-paying enterprises; (2) enable the contractor to use it as an added value in the bidding process; (3) realize data sharing in a common platform to improve the cost segregation study efficiency and reduce costs and errors; (4) contribute to the asset management in the life cycle of buildings while filling in the blank of cost segregation process. Future studies will focus on the automation of cost segregation and asset management in building construction's life cycle.

• Strategy21
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• s.30
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• pp.200-235
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• 2012

Over the past few years, due to the climate change of the earth, the Arctic's sea ice cover is undergoing a historic transformation - thinning, extent reduction in all seasons, and mitigation in the area of multi-year ice in the central Arctic Ocean. These changes allow for increases in maritime access throughout the Arctic Ocean and for potential longer seasons of navigation and possibly transarctic voyage in the summer. These changes also allow more exploration for oil, gas, and other minerals. The Arctic is now an archetype of the complex, multi-dimensional global problems of the twenty-first century. Military security, environmental security, and economic security interact. The potentially enormous economic stakes, sufficient to change the strategic balance among the states of the region, set off competitive pressures for national advantage. Korea, which is heavily dependent upon the sea lane in terms of transportation of its exports and imports, is very much interested in the Arctic sea routes. Korea believes that the Artic sea route, particularly the Northern Sea Route (NSR), could serve as a new useful sea lane, which will enable shorter times between East Asia and Europe, thus resulting in substantial cost saving for ship operators. In addition to shipping, Korea is interested in other Arctic-related maritime industries. Korea, as a leading shipbuilder in the global market, is interested in building ice breakers, drill ships, and other vessels which can contribute to safe operation in Arctic resource development and exploration. Korea, as one of the future stakeholders in Arctic maritime activities, should be ready to foster international cooperation in the region.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1053-1063
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• 2014

This study presents a sustainable design method that optimizes the embodied energy of concrete beam based on the concept of sustainable development that effectively utilizes natural resource and energy within the range that our succeeding generation can afford to utilize. In order to get the flexural strength carrying the ultimate load, concrete beam sections are designed by optimization that consists of the embodied energy as a objective function and the requirements of design code as constrained conditions. The sustainable design can be used to minimize the embodied energy consumed in material production, construction, operation, demolition of the infrastructure. As a result of comparison of the cost and the embodied energy optimizations based on practical beam sections, it is shown that 20% embodied energy saving and 35% $CO_2$ emission saving are achieved by sacrificing 10% cost increase. The sustainable design method provides a new effective methodology that manages the strength design concept based on cost minimization together with economic feasibility and sustainability. In addition, the method is expected to be applied to more various structural design practices.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.91-100
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• 2011

Green technologies of buildings are spreading for saving resource and energy consumption during life cycle of buildings. However, selection of optimized the technologies for applying projects is needed a lot of time and costs. Therefore prioritization is necessary to apply the technologies for buildings. An evaluation of economic value for the technologies is significant for prioritization of the technologies, however, the current evaluation system of economic value for technologies is not reflected the accurate features of the technologies. Green technologies have the objectives for reducing the emission of CO2 and saving the cost during the whole lifecycle of buildings. Thus the evaluation of economic feasibility for green technologies is needed to include the economic value from improving the environment. This paper developed the economic evaluation method integrated with LCC and LCA to accurately analyze the economic value for green technologies. Moreover, this paper drew the priority of the technologies by conducting case studies with the integrated method and analyzing the results with AHP. The conclusion of case studies, Green technologies is worth more if to include the economic value from improving the environment. Then in analysis of priority, Green intelligent component technologies were rated the highest. The conclusion of the study is able to utilize the supporting tool for making decision to select the optimized technologies for the projects and precedence study for developing future research of prioritization for green technologies. The future study for improving the developed method will supplement the various evaluation factors and apply the detailed weight to analyze the priority of green technologies.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.570-581
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• 2015

In recent years, many institutions predict that cloud services and big data will be popular IT trends in the near future. A number of leading IT vendors are focusing on practical solutions and services for cloud and big data. In addition, cloud has the advantage of unrestricted in selecting resources for business model based on a variety of internet-based technologies which is the reason that provisioning and virtualization technologies for active resource expansion has been attracting attention as a leading technology above all the other technologies. Big data took data prediction model to another level by providing the base for the analysis of unstructured data that could not have been analyzed in the past. Since what cloud services and big data have in common is the services and analysis based on mass amount of data, efficient operation and designing of mass data has become a critical issue from the early stage of development. Thus, in this paper, I would like to establish data processing architecture based on technological requirements of mass data for cloud and big data services. Particularly, I would like to introduce requirements that must be met in order for distributed file system to engage in cloud computing, and efficient compression technology requirements of mass data for big data and cloud computing in terms of cost-saving, as well as technological requirements of open-source-based system such as Hadoop eco system distributed file system and memory database that are available in cloud computing.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.54-64
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• 2015

The modular construction has several advantages such as high quality of product, safe work condition and short construction duration. The manufacturing planning of modular construction should consider time frame of manufacturing, transport and erection process with limited resources (e.g., modular units, transporter and workers). The manufacturing planning of multi modular construction project manages the modular construction's characteristics and diversity of projects, as a type of modular unit, modular unit quantities, and date for delivery. However, current modular manufacturing planning techniques are weak in dealing with resource interactions and each project requirement in multi modular construction project environments. Inefficient allocation of resources during multi modular construction project may cause delays and cost overruns to construction operation. In this circumstance, this research suggest a manufacturing planning model for schedule optimization of multi project of modular construction, using genetic algorithm as one of the powerful method for schedule optimization with multiple constrained resources. Comparing to the result of the existed schedule of case study, setting optimized scheduling for multi project decrease the total factory producing schedule. By using proposed optimization tool, efficient allocation of resource and saving project time is expected.

• KDI Journal of Economic Policy
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• v.32 no.1
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• pp.27-49
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• 2010

This paper provides insight into some important features of the intergenerational resource allocation in Korea, before and after the financial crisis in 1997-98. Data sets of three periods before and after the financial crisis (1996, 2000, and 2005) were used to compare the results. This research particularly addresses two related issues: i) the generational effects of economic crisis, and ii) the capacity of age reallocation systems to spread economic risks across generations. The results show tremendous consumption smoothing and resource reallocation by age, during and after the financial crisis. Private education and private health consumption decreased for children between 1996 and 2000. However, the decrease in private education and private health consumption was mitigated by the increase in public consumption. It appears that the public sector did not only mitigate the adverse impact of the economic crisis on consumption, but it also reduced the widening disparity amongst generations. Within transfers, the public transfers for the elderly increased substantially as the private transfers decreased rapidly. Finally, there was a big increase in the asset-based reallocation of the elderly. The increase in asset-based reallocation was mainly due to an increase in asset income between 1996 and 2000, but it was almost entirely due to a decrease in saving (i.e. an increase in dissaving) between 2000 and 2005. This suggests that Korean elderly seemed to have some degree of supporting system during the crisis, even without sufficient pension benefits. The increased reliance on asset accumulation will be critical in the long-run in Korea, as public pension funds diminish due to population aging.