• Journal of Electrical Engineering and Technology
• /
• v.8 no.6
• /
• pp.1251-1260
• /
• 2013

This paper presents the optimal scheduling of hourly consumption in a residential community (community, neighborhood, etc.) based on real-time electricity price. The residential community encompasses individual residential loads, communal (shared) loads, and local generation. Community-aggregated loads, which include residential and communal loads, are modeled as fixed, adjustable, shiftable, and storage loads. The objective of the optimal load scheduling problem is to minimize the community-aggregated electricity payment considering the convenience of individual residents and hourly community load characteristics. Limitations are included on the hourly utility load (defined as community-aggregated load minus the local generation) that is imported from the utility grid. Lagrangian relaxation (LR) is applied to decouple the utility constraint and provide tractable subproblems. The decomposed subproblems are formulated as mixed-integer programming (MIP) problems. The proposed model would be used by community master controllers to optimize the utility load schedule and minimize the community-aggregated electricity payment. Illustrative optimal load scheduling examples of a single resident as well as an aggregated community including 200 residents are presented to show the efficiency of the proposed method based on real-time electricity price.

• Journal of Korean Society of Rural Planning
• /
• v.25 no.1
• /
• pp.99-111
• /
• 2019

To analyze main factors of size planning of community facilities that were created as part of development of a rural area, the present condition of factors deciding size of community facilities was analyzed, factors that influence size planning by the type of community facility were drawn with Delphi anaysis. The results of analyzing the present condition of size planning factors of community facilities show that facilities have been generally planned as multi-purpose and multi-functional facilities. And on the basis of the purpose of facilities, their functions and organization, and their operation programs, facilities are classified into community-centered, agritourism-centered, and combined ones. Using Delphi analysis, major factors that could affect size planning of community facilities were drawn on 26 community-centered, 28 agritourism-centered, and 30 combined. And the factors tended not to be applied well for size planning of community facilities.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.7
• /
• pp.3041-3063
• /
• 2018

Community search aims at finding a meaningful community that contains the query node and also maximizes (minimizes) a goodness metric. This problem has recently drawn intense research interest. However, most metric-based algorithms tend to include irrelevant subgraphs in the identified community. Apart from the user-defined metric algorithm, how can we search the natural community that the query node belongs to? In this paper, we propose a novel community search algorithm based on the concept of the k-hop and local distance dynamics model, which can naturally capture a community that contains the query node. The basic idea is to envision the nodes that k-hop away from the query node as an adaptive local dynamical system, where each node only interacts with its local topological structure. Relying on a proposed local distance dynamics model, the distances among nodes change over time, where the nodes sharing the same community with the query node tend to gradually move together, while other nodes stay far away from each other. Such interplay eventually leads to a steady distribution of distances, and a meaningful community is naturally found. Extensive experiments show that our community search algorithm has good performance relative to several state-of-the-art algorithms.

• Journal of Korea Technology Innovation Society
• /
• v.13 no.4
• /
• pp.758-771
• /
• 2010

Korea is characterized by a high R&D expenditure rate to the GDP. The performance of R&D in Korea, however, hardly seems to be satisfied. The purpose of this study is to investigate the influence of strategic resources and community engineering on R&D performance in bio-tech industry in Korea. The results of the study show strategic resources and community engineering are determinants of technological outcome. The strategic resources have a Significant positive effect on economic impact whereas community engineering has no Significant effect. In addition, the study results reveal that there is no moderating effect of strategic resources on the relation between community engineering and R&D performance. The major limitations of the study are on the measure of the variables.

• Journal of Korean Society of Rural Planning
• /
• v.19 no.2
• /
• pp.51-61
• /
• 2013

The purpose of this study is to conduct an analysis of rural village's community status and consciousness through a questionnaire survey of community leaders and members. Nine types of rural village communities were selected in Korea through a pre-survey of amenity resources data from the Rural Development Administration. Survey items that could determine characteristics of rural village communities were derived from a literature survey of rural village community systems. A questionnaire survey was conducted for 12 Eup-Myeon in Yesan Gun and responses were gathered from 66 community leaders and 1,222 community members. The results derived from the data collected from the community leaders show that 50% percent of rural village communities have been operating for over 25 years, and that community works such as group purchases are carried out based on emotional sympathies between residents. The results derived from the data collected from community members show that on average, community activities are carried out at places that are between 30 and 60 minutes away. Most members are satisfied with regard to the status of their rural village community. A correlation analysis showed that the rural village community satisfaction depended on travel time, community fee, and activity time.

• Journal of Engineering Education Research
• /
• v.13 no.2
• /
• pp.12-15
• /
• 2010

Learning community is one of the important pillars of the education in knowledge-based society. How to encourage students' spontaneous participation to the learning community is one of the actual problems to solve for the revolution of the education scheme. In this paper we introduce a strategy to boost the activity of the learning community, which works in the on-line space. The keys for the on-line supporting system for the learning community are to have communication space, trading space and connection with industry. To support activities of each space, we provide an on-line web site which includes a community module, a knowledge market module and an industrial commentary module. Students can start their self-leading study in the communication space, and they can also practice skills for the knowledge management in the knowledge trading space. Through the connection space, they can learn more from the real world critics with help of industry.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.61 no.5
• /
• pp.11-22
• /
• 2019

The purpose of this study was to examine the relationships between the community business, performance and the life satisfaction of local residents and to investigate the mediating effects that community business performance has on the life satisfaction of local residents. The results of the study investigating the effect of community business, performance and the residents' life satisfaction mediating effect of performance are summarized as follows: First, there were differences with the economical, environmental, and performance factors pertaining to the participants' age while there were no differences concerning the social-cultural factors and the life satisfaction of local residents. Second, the higher the impact a community business has, the higher the life satisfaction of the local residents have. In addition, the higher the performance in community business, the more ready local residents are to be inclined to be satisfied. Third, economical and environmental factors have direct effects on the life satisfaction of local residents, but also indirectly effect the performance of local residents. In addition, the level of performance that a community business plays has a mediating role in the life satisfaction of local residents.

• Wind and Structures
• /
• v.30 no.2
• /
• pp.165-180
• /
• 2020

To determine tornadic wind loads, the wind pressure, forces and moments induced by tornadoes on civil structures have been studied. However, in most previous studies, only the individual building of interest was included in the wind field, which may be suitable to simulate the case where a tornado strikes rural areas. The statistical data has indicated that tornadoes induce more significant fatalities and property loss when they attack densely populated areas. To simulate this case, all buildings in the community of interest should be included in the wind field. However, this has been rarely studied. To bridge this research gap, this study will systematically investigate the influence of a community of buildings on tornadic wind fields by modeling all buildings in the community into the wind field (designated as "the Community case under tornadic winds"). For comparison, the case in which only a single building is included in the tornadic wind field (designated as "the Single-building case under tornadic winds") and the case where a community of buildings are included in the equivalent straight-line wind field (designated as "the Community case under straight-line winds") are also simulated. The results demonstrate that the presence of a number of buildings completely destroys the pattern of regular circular strips in the distribution of tangential velocity and pressure on horizontal planes. Above the roof height, the maximum tangential velocity is lower in the Community case under tornadic winds than that in the Single-building case under tornadic winds because of the higher surface friction in the Community case; below the roof height, greater tangential velocity and pressure are observed in the Community case under tornadic wind fields, and more unfavorable conditions are observed in the Community case under tornadic winds than under the equivalent straight-line winds.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.10
• /
• pp.1428-1433
• /
• 2013

Jeotgal fermentation is dependent upon a diverse microbial community, although a detailed understanding of its microbial composition is limited to a relatively small number of jeotgal. Pyrosequencing-based bacterial community analysis was performed in fermented squid, ojingeo jeotgal. Leuconostoc was identified as the predominant bacterial genus, with Bacillus and Staphylococcus also accounting for a large proportion of the bacterial community. Phylogenetic analysis with 16S rRNA genes of Leuconostoc type species indicated that L. citreum- and L. holzapfelii-like strains could be the major Leuconostoc strains in jeotgal. High concentrations of NaCl were thought to be an important factor determining the makeup of the bacterial community in the fermented squid; however, a genomic survey with osmotic stress-related genes suggests the existence of more complex factors selecting the dominant bacterial species in fermented squid.

• Korean Chemical Engineering Research
• /
• v.48 no.2
• /
• pp.147-156
• /
• 2010

There are four key factors for gas-phase biofilters; biocatalysts(microorganisms), packing materials, design/operating techniques, and diagnosis/management techniques. Biofilter performance is significantly affected by microbial community structures as well as loading conditions. The microbial studies on biofilters are mostly performed on basis of culture-dependent methods. Recently, advanced methods have been proposed to characterize the microbial community structure in environmental samples. In this study, the physiological, biochemical and molecular methods for profiling microbial communities are reviewed, and their applicability to biofilters is discussed. Community-level physiological profile is based on the utilization capability of carbon substrate by heterotrophic community in environmental samples. Phospholipid fatty acid analysis method is based on the variability of fatty acids present in cell membranes of different microorganisms. Molecular methods using DNA directly extracted from environmental samples can be divided into "partial community DNA analysis" and "whole community DNA analysis" approaches. The former approaches consist in the analysis of PCR-amplified sequence, the genes of ribosomal operon are the most commonly used sequences. These methods include PCR fragment cloning and genetic fingerprinting such as denaturing gradient gel electrophoresis, terminal-restriction fragment length polymorphism, ribosomal intergenic spacer analysis, and random amplified polymorphic DNA. The whole community DNA analysis methods are total genomic cross-DNA hybridization, thermal denaturation and reassociation of whole extracted DNA and extracted whole DNA fractionation using density gradient.