• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4774-4796
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• 2018

Wireless sensor networks are composed of a large number of inexpensive and tiny sensors used in different areas including military, industry, agriculture, space, and environment. Fault tolerance, which is considered a challenging task in these networks, is defined as the ability of the system to offer an appropriate level of functionality in the event of failures. The present study proposed an intelligent throughput descent and distributed energy-efficient mechanism in order to improve fault tolerance of the system against soft and permanent faults. This mechanism includes determining the intelligent neighborhood radius threshold, the intelligent neighborhood nodes number threshold, customizing the base paper algorithm for distributed systems, redefining the base paper scenarios for failure detection procedure to predict network behavior when running into soft and permanent faults, and some cases have been described for handling failure exception procedures. The experimental results from simulation indicate that the proposed mechanism was able to improve network throughput, fault detection accuracy, reliability, and network lifetime with respect to the base paper.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1499-1504
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• 2013

As oil price and demand for environment friendly vehicle rapidly increase, research on electric car is being widely carried out. Especially, NEV(Neighborhood Electric Vehicle) is a pollution-free vehicle that can be mass-produced which the time of development for related technologies is urgently needed. In this paper the On-Board charger for mid- and large- sized secondary cell is applicable in aerospace and other general industries, and the Off-Board standing charger is expected to be employed in creating charging infrastructure.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.151.5-151
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• 2001

Sliding mode control is investigated for a discrete-time system with uncertainties. The narrowest neighborhood of the sliding surface is shown in which the state can remain. The range is determined by the upper bound of the absolute value of the uncertainty and the equation of the sliding surface. A sliding mode control algorithm is proposed to keep the state there without requiring an enormous input. Under the presence of the system parameter variations, the origin is not always stable although the sliding surface represents the stable dynamics and the state is kept in this neighborhood. The condition for the origin to be stable is investigated. Furthermore, the problems occurring when a continuous-time sliding mode control being ...

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.77-84
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• 2021

In this study, In order to apply the U-flanged truss hybrid beam to the actual construction site, the structural design of the basic module of the middle and low-rise neighborhood living facilities was performed according to the Korea Design Standard, and the construction cost and construction period were compared with the traditional reinforced concrete structure system. As a result of analyzing the construction cost for the basic module, if the U-flanged truss hybrid beam and D-Deck slab system are used, the construction cost can be reduced by 86% compared to the traditional reinforced concrete structure system. In addition, as a result of analyzing the construction period for a floor area of 1,000m², using the U-flanged truss hybrid beam and D-Deck slab system can save 2.0days in construction period compared to the traditional reinforced concrete structure system. Therefore, the U-flange truss hybrid beam can secure sufficient economic feasibility compared to the existing reinforced concrete method in terms of cost reduction and shortening of construction period.

• Korean Journal of Mathematics
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• v.5 no.2
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• pp.211-215
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• 1997

In this paper, we introduce two notions of compactness defined by sequential convergence and compare them.

• Journal of the Korean housing association
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• v.24 no.6
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• pp.189-197
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• 2013

The purpose of the study was to analyze the improvement elements depended on housing quality measurement tool related to mental health. The data for the analysis was collected through questionnaire survey method from November 1, 2012 to January 17, 2013, and the sample consisted of 720 respondents living in single detached houses, multi-families detached houses, apartments, and town houses in 4 cities, Seoul, Busan, Daejeon, and Kwangju. The data were analyzed using descriptive statistics. The results of improvement elements are as follows: 1) Pedestrian-threaten street from cars in physical safety 2) A secluded or dark spot and fear of walking at night in social security, 3) Indoor noise, outdoor noise, and evidence of abandoned trash heap/bottle in neighborhood in health & sanitation, 4) Illegal parking and heating control system in facility convenience, 5) Extra kitchen, number of bathrooms, and community spaces in space convenience, 6) Openness and spaciousness of indoor room, and satisfaction of house and neighborhood in comfort, 7) Management common/sharing space in maintenance, 8) Energy saving facility and environment friendly materials use in sustainability, 9) Burden on housing cost, asset value on house, and school district in economic value, 10) Reflection of residents style, surrounding building's number of layers, and neighborhood appearance of preference in housing environment image.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.1-14
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• 2007

This study was conducted to propose the plan of creating a brooklet reflecting an water-friendly space as well as its function as the habitats of wildbird in Cheongdam Neighborhood Park in Seoul. Major fields of this study include a survey of the staus, a basic plan, a master plan, a execution; a survey of this site was focused on topography, water system, trail, existing vegetation, wildbird; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 5 types; Quercus mongolica-Q. acutissima forest, Robinia pseudoacacia forest, Populus${\times}$albaglandulosa forest, artificial green space, urban area. 11 species and 49 individuals of wildbirds appeared in 2004(3~4month). The plan of creating a brooklet were divided passive-zone, eco-zone, and dynamic-zone. Environment elements of each space including a mountain stream, ecological pond, marshland, ecological landscape forest, wildbird observation trail, waterway etc. The brooklet of Cheongdam Neighborhood Park is rated high as an important space for wildbird biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.

• Journal of Multimedia Information System
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• v.9 no.2
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• pp.87-92
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• 2022

In this study, we aimed to illustrate that the thresholding method gives different results when tested on the original and the refined histograms. We use the global thresholding method, the well-known image segmentation method for separating objects and background from the image, and the refined histogram is created by the neighborhood distinction metric. If the original histogram of an image has some large bins which occupy the most density of whole intensity distribution, it is a problem for global methods such as segmentation and contrast enhancement. We refined the histogram to overcome the big bin problem in which sub-bins are created from big bins based on distinction metric. We suggest the refined histogram for preprocessing of thresholding in order to reduce the big bin problem. In the test, we use Otsu and median-based thresholding techniques and experimental results prove that their results on the refined histograms are more effective compared with the original ones.

• Convergence Security Journal
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• v.9 no.1
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• pp.19-27
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• 2009

In this paper, we propose a safety management system which prevents the occurrence of crime and accident from rising in school neighborhood. This system offers a monitoring method for safety of children which make intelligent space from environment and location sensing data through wireless communication between sensors attached to children and fixed sensor network in school neighborhood. Also, We propose a strategic safety management plan using opportunistic network when node is out of school zone network. Many students can easily receive the service of low cost from WSN-based School zone network than existing service from GPS individually by using our scheme.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.5
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• pp.106-122
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• 2010

With the introduction of the 40 hours workweek system, an intensive discussion was made among relevant departments. Building facilities does not necessarily guarantee more leisure activities and higher satisfaction for the public. It is essential to draft at the trend of leisure policy in Japan and learn from the experiences to set the policy direction best fitting future changes in Korea, as Japan has gone through comprehensive changes ahead of us. With this understanding, this study analyzed key leisure policies of Japan and examined the trend of changes of time. The followings are the findings of the research. First, Japan's leisure policies could be categorized into five stages and six terms. Second, leisure policies in Japan are being established as a local welfare system, not in the context of industrial perspective, to help people in local community. This is to make voluntary move by eliminating the factors that restrict social demand with an effort to expand leisure time and to secure and enhance access to leisure space. Third, Neighborhood leisure space has taken the center stage, in an effort to seek solutions to the issues of improving space utilization, restoring local community and encouraging participation of local residents. The conclusion drawn from the research is as follows. It is required to recommend the use of the specific term 'leisure' for leisure policies in Korea and for leisure space policies in Korea that are now facing sociocultural challenges similar to the ones emerging in Japan, measures are required to improve physiological access of local residents including information promotion, lifetime education and relationships enhancement along with the establishment of neighborhood leisure space.