• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.79-89
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• 2009

More and more domestic skyscrapers have been rapidly constructed to get enough living space for people living in overcrowded cities. The purpose of skyscrapers is to provide citizens with useful facilities and to establish landmarks and also national and regional symbols. Previous studies have been conducted which focused on the structure, materials, plans, maintenance, and relevant information regarding skyscrapers. Skyscrapers, however, are different from other smaller buildings regarding the residential environment as well as in other ways. Recently, several problems have been raised in that the indiscreetness of current skyscrapers cannot guarantee residents a high quality living environment, and they might contain risks unless criteria are put forward to ensure that the design and facilities provide for this aim. It is judged that a set of performance criteria for the residential environment to ensurethe residents' quality of life could solve this problem. This study therefore aims to suggest a method for the improvement of the residential environment of skyscrapers by establishing residential environment evaluation factors. In conclusion, this study calculates the weight of each evaluation factor using AHP (an analytic hierarchy process) and suggests evaluating criteria. It is expected that this study could be used to propose guidelines for residents at the design and planning stage of building a skyscraper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1663-1670
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• 2014

Stress is closely associated with oral diseases, being considered to be one of important variables to affect the improvement of oral health and the quality of life. In this study, a survey was conducted on 550 adults from July 1, 2012, to February 28, 2013. A path analysis was carried out to determine the influence of physical stress symptoms and psycho-emotional stress symptoms on dry mouth, oral mucosal disease and halitosis symptoms. The findings of the study were as follows: Oral mucosa affected halitosis in a direct effect and dry mouth exerted a direct influence on that as well. When stress symptoms affected halitosis, dry mouth and oral mucosa had an indirect impact on that as parameters. Dry mouth exercised a direct influence on oral mucosa. The above-mentioned findings suggested that the physical stress symptoms and psycho-emotional stress symptoms of the adults affected their dry mouth, oral mucosal disease and halitosis both in direct and indirect effects. As the stress of adults is closely bound up with their oral diseases, how to properly cope with stress should carefully be considered in order for them to lead a better life.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.12a
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• pp.35-42
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• 2004

In spite of economic slump of global IT market, China is showing growth of $25\%$ per a year. After opening economy, the economic growth of the country haven't flagged. Moreover, According to the economic plan of the President HuJinTao who took office in 2002, IT field has been developing quickly. Even though such development is enough to show off the ability of China in the world, it is also a fart that there are many side effects. Among them, the imbalance of development between the east and the west is disturbing the general Chinese development. So the government is making efforts to reduce the gap as a solution, 'Go West campaign.' While progressing the policy, the related method which restricted domestic demand market advance from 2000 is abolished. We also established a bridgehead for lauching to the west of China at the same line with other developed countries. Based ell such reality, we understands the general present state and policy of Chinese IT industrial and the opportunity for abolishing the related method which restricted domestic market advance to also obtain from 2000, and for our country to also advance to the western area in China by the start onboard equal to other advanced nations. The direction to which we have to go by investigating the situation of a western area is investigated.

• The KIPS Transactions:PartA
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• v.17A no.6
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• pp.265-274
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• 2010

As the process technology scales down and integration densities continue to increase, interconnection has become one of the most important factors in performance of recent multi-core processors. Recently, to reduce the delay due to interconnection, 3D architecture has been adopted in designing multi-core processors. In 3D multi-core processors, multiple cores are stacked vertically and each core on different layers are connected by direct vertical TSVs(through-silicon vias). Compared to 2D multi-core architecture, 3D multi-core architecture reduces wire length significantly, leading to decreased interconnection delay and lower power consumption. Despite the benefits mentioned above, 3D design technique cannot be practical without proper solutions for hotspots due to high temperature. In this paper, we propose three floorplan schemes for reducing the peak temperature in 3D multi-core processors. According to our simulation results, the proposed floorplan schemes are expected to mitigate the thermal problems of 3D multi-core processors efficiently, resulting in improved reliability. Moreover, processor performance improves by reducing the performance degradation due to DTM techniques. Power consumption also can be reduced by decreased temperature and reduced execution time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1091-1101
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• 2012

Device-to-device (D2D) communication is expected to offer local area services with low transmit power and short link distance, even not via any infrastructures. These advantages will lead to the deployment of D2D systems in a massive scale, where the order of magnitude of D2D user density is higher than that of cellular user density. Network-assisted D2D systems, where D2D resources are managed by cellular networks, are unable to support the large number of D2D devices, due to the signaling overhead for control signals. In this case, no coordination can be an answer. This paper considers uncoordinated D2D systems, which is implemented with a number of D2D devices in a large scale. By analyzing the transmission capacity of D2D systems, we found a feasibility condition under which the uncoordinated D2D communications possibly coexist within cellular networks, sharing the uplink spectrum. In addition, we provide guidelines for the operational points of massive D2D communications, giving some knowledge about proper transmit power level and link distance of uncoordinated D2D.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.797-803
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• 2019

This study was carried out to reduce the lateral vibration of high-speed electric multiple units. In the study, the high-speed electric multiple unit prototype (HEMU-430X) has a high lateral vibration at low equivalent conicity regardless of the wheel profiles (XP55, GV40, S1002). As wheel wear progresses and the equivalent conicity increases, the lateral vibration tends to decrease. The reason is that a combination of the suspension characteristics causes the body and bogie to resonate at a frequency of 1.4 Hz when the equivalent conicity is low, resulting in body hunting. An investigation of the lateral vibration of overseas high-speed trains showed that a decrease in the hydraulic stiffness of the yaw damper could improve the vibration. The series stiffness of the yaw damper is a combination of the hydraulic stiffness and elastic joint. In this study, an attempt was made to improve the lateral vibration by lowering the stiffness of the elastic joint. The series stiffness of the adjusted yaw damper was approximately 60% compared to the original one. The on track test results showed improvement in the lateral vibration for both running directions. The vibration reduction method of this study can be used for EMU-250 and EMU-320 in future commercial operations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.762-767
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• 2017

This paper presents an analysis for improving the power transfer capability in transmission lines caused by the movable load charging of electric vehicles (EVs). EVs are expected to be used more widely and replace gas fuel vehicles in the near future due to the shortage of fossil fuels and for environmental preservation. Movable load charging of EVs could lead to the convergence of transferred power flow and overloading conditions in transmission lines in a specific area of a power system, which is conventionally based on estimated fixed load capability. To analyze these conditions, the New England Test System was divided into four regions based on the load characteristics, and different charging scenarios were considered. In these scenarios, the regional power load was highly increased to 31% based on the standard charging capacity of an EV. As a solution to the overloading problem of transmission lines, a TCSC was installed serially on the overloaded line to directly control the transferred power under limited line capability (100% load capability). The simulation showed that the application of a few TCSCs could efficiently and economically control the line capability problem caused by movable load charging of EVs.

• Journal of KIISE
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• v.43 no.10
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• pp.1115-1123
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• 2016

Assumption-based truth maintenance system (ATMS) is a tool that maintains the reasoning process of inference engine. It also supports non-monotonic reasoning based on dependency-directed backtracking. Bookkeeping all the reasoning processes allows it to quickly check and retract beliefs and efficiently provide solutions for problems with large search space. However, the amount of data has been exponentially grown recently, making it impossible to use a single machine for solving large-scale problems. The maintaining process for solving such problems can lead to high computation cost due to large memory overhead. To overcome this drawback, this paper presents an approach towards incrementally maintaining the reasoning process of inference engine on cluster using Spark. It maintains data dependencies such as assumption, label, environment and justification on a cluster of machines in parallel and efficiently updates changes in a large amount of inferred datasets. We deployed the proposed ATMS on a cluster with 5 machines, conducted OWL/RDFS reasoning over University benchmark data (LUBM) and evaluated our system in terms of its performance and functionalities such as assertion, explanation and retraction. In our experiments, the proposed system performed the operations in a reasonably short period of time for over 80GB inferred LUBM2000 dataset.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.627-653
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• 2010

The present study proposes and examines a new type of multiple-choice math test. In this format, the options are the intermediate derivatives of the math problem solution process rather than the final answers. This idea originates from the studies on the effect of worked-out examples. In these studies, it has been shown that students learn better when they were presented with worked-out examples than when presented with final answers by themselves. In line with these findings, we introduced the intermediate derivatives of the solution process as the options of multiple-choice items so that the test-taker will have a chance to examine the solution process. The test was implemented as a computerized test in which students can solve problems in a short answer format, and then pick a multiple-choice option which appears when requested. The experimental group had multiple-choice options which were intermediate derivatives of the solution process, and the control group had the final answers as the options as in most multiple-choice tests. The participants were 6th graders in elementary school. The posttest results revealed that the average score of the experimental group was higher than that of the control group. The results suggest that tests that use intermediate derivatives of the problem solution process as options can be used as learning tools in the classrooms. Finally, directions for further studies were discussed.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.549-564
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• 2017

Not only services that are provided by a single system have been various with the development of the Internet of Things and autonomous software but also new services that are not possible before are provided through collaboration between systems. The collaboration between autonomous systems is similar to the ecosystem configuration in terms of biological viewpoints. Thus, it is called the IT Ecosystem, and this concept has arisen newly in recent years. The IT Ecosystem refers to a concept that achieves a mission of each of a number of heterogeneous systems rather than a single system utilizing their own autonomy as well as achieving the objectives of the overall system simultaneously in order to meet a single common goal. In our previous study, we proposed architecture of elementary level and as well as basic several meta-models to implement the IT Ecosystem. This paper proposes comprehensive reference architecture framework to implement the IT Ecosystem by cleansing the previous study. Among them, a utility function based on cost-benefit model is proposed to solve the dynamic re-configuration problem of system components. Furthermore, a measure of using genetic algorithm is proposed as a solution to reduce the dynamic re-configuration overhead that is increased exponentially according to the expansion of the number of entities of components in the IT Ecosystem. Finally, the utilization of the proposed orchestration framework is verified quantitatively through probable case studies on IT Ecosystem for unmanned forestry management.