• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.14-22
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• 2007

Wireless sensor networks are composed of numerous sensor nodes and exchange or recharging of the battery is impossible after deployment. Thus, sonsor nodes must be very energy-efficient. As neighboring sensor nodes generally have the data of similar information, duplicate transmission of similar information is usual. To prevent energy wastes by duplicate transmissions, it is advantageous to organize sensors into clusters. The performance of clustering scheme is influenced by the cluster-head election method and the size or the number of clusters. Thus, we should optimize these factors to maximize the energy efficiency of the clustering scheme. In this paper, we propose a new energy consumption model for LEACH which is a well-known clustering protocol and determine the optimal number of clusters based on our model. Our model has accuracy over 80% compared with the simulation and is considerably superior to the existing model of LEACH.

• Journal of Energy Engineering
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• v.16 no.3
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• pp.128-148
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• 2007

Quality assurance (QA) for nuclear R&D project is very concerned about the poor economy due to the improper selection of QA requirements. This paper proposes a new methodology for determining the relative importance weights of QA requirements considering the attributes of nuclear R&D project. QFD (Quality Function Deployment) is used as a conceptual framework and fuzzy number is introduced to capture the vagueness uncertainty existing in human judgement. Also we use a confidence attitude of decision-maker in order to improve the reliability of extracted attribute level of R&D project. Case study on a nuclear R&D project and scenario analysis are carried out to verify the usefulness and effectiveness of proposed methodology.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.83-94
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• 2016

Energy use has been recognized worldwide as a main cause of global warming and it is at the center of climate change. In this study, problems and measures of zero-energy building construction are investigated and analyzed. Based on the results, evaluation criteria of the zero-energy building are suggested. Performance related factors(Q) representing the environmental grade were divided into three categories as outdoor, indoor environment and maintenance. Energy related factors(LR) representing the energy load were divided into an energy, materials & resources, water cycle management, land use and transportation. Detailed fifty three items are listed for the evaluation under the consideration of energy, water cycle management sections gave weight. Upon receiving the first in the environment friendly certification system, Seoul Central Post Office and Seoul Metropolitan Water Supply Center evaluated. The reason why this score difference is due to lack of use of new generation energy building construction is required expensive costs so need expansion of governmental support. This effort is successful zero energy building construction and copes with global warming and climate change.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.41-47
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• 2010

The emergency between vehicles on the superhighway should be transmitted quickly to the following vehicles for safety of people. The message between them has been transmitted by broadcast method in an wireless environment of 802.11, so far. That causes the broadcast storm and a waste of the bandwidth of Wireless network owing to unnecessary process of sending messages to even vehicles that do not have to receive the information. The message collision is a main cause of the increase of message delay. In order to overcome the existing problem, this paper proposed a message broadcast scheme based on cell (MBC), which is the way to divide cars into different groups by cell unit and transmit messages to the members of the groups through the cell primary (cp) vehicles. This paper shows the proposed broadcast's performance in the same environment is much superior to other conventional broadcast schems for inter-vehicle communication, since the receiving ratio among the following vehicles is improved.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.121-129
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• 2011

One of the major challenges of minimum energy consumption for wireless sensor networks(WSN) environment. LEACH protocol is hierarchical routing protocol that obtains energy efficiency by using clustering. However, LEACH protocol in each round, because the new cluster configuration, cluster configuration, whenever the energy consumed shorten the life of the network. Therefore in this paper, the cluster is formed in WSN environment in early stage and the problems with energy waste have been solved by selecting C-node. In the initial round of proposed model uses 26 percent more than traditional LEACH energy consumption. However, as the round is ongoing, it has been proved by the network simulation tool that the waste of energy could be diminished up to 35%.

• Korean Journal of Construction Engineering and Management
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• v.9 no.4
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• pp.154-162
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• 2008

Ministry of construction and transportation has been enforcing extensionally design phase VE(Value Engineering) to the construction costing more than 10 billion won, an importance of design phase VE accordingly is raising to get rid of a waste of cost and noneffective factors previously in construction projects. Although there are legal supports and technical effects, an effect about an introduction of design phase VE can not be applied properly because of several problems at the process. So, in this study, present competency factors of design phase VE to highly raise the output through organizing an effective team at the beginning stage of design phase VE. Find out 29 competency factors through characteristics of design VE team for the check list, classify by team knowledge, team work skill, and team attitude. Get an efficiency regarding importance and find out Competency Evaluation items of design VE team, present a Competency Evaluation plan for indicating an objective standard to Competency Evaluation by measuring relative importance as to each Competency Evaluation item.

• Archives of design research
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• v.17 no.3
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• pp.363-372
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• 2004

Lannon(1994) asserted, 'Today consumer market has reached its maturity, and products gets more and more similar. So brands should be distinguished from competitors by emotional values.' Parody ads, one of advertisements appealing to emotion, would distort some original work well known to the public with its blemish or seriousness on target by imitating or exaggerating it regardless of expression styles, and announce the results to criticize the work itself or social situations or excite laughter. Such parody ads are stimulating consumers' emotion in particular and diverse methods. But This study on parody and especially parody in advertising, deals with the basic concepts of parody in advertising, as well as copyright infringement issues highlighting the different legal interpretations in American and Korean law when dealing with indiscreet cases of parody in advertising. some suggestions are made on desirable and forword-looking solutions. Different to the acceptance of parody in the American culture, Korean law was limiting in allowing parody to be used and applied.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.1-15
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• 2019

One of the biggest difficulties in the vocational training field is the dropout problem. A large number of students drop out during the training process, which hampers the waste of the state budget and the improvement of the youth employment rate. Previous studies have mainly analyzed the cause of dropouts. The purpose of this study is to propose a machine learning based model that predicts dropout in advance by using various information of learners. In particular, this study aimed to improve the accuracy of the prediction model by taking into consideration not only structured data but also unstructured data. Analysis of unstructured data was performed using Word2vec and Convolutional Neural Network(CNN), which are the most popular text analysis technologies. We could find that application of the proposed model to the actual data of a domestic vocational training institute improved the prediction accuracy by up to 20%. In addition, the support vector machine-based prediction model using both structured and unstructured data showed high prediction accuracy of the latter half of 90%.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.99-107
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• 2008

Rapidly increasing automobile supply rate according to improved economic level of life makes lack of parking space of apartments. Even though the initial design of parking space compiled with old regulations, it may not observe either new laws or requirement of inhabitants. Even if old apartments have no structural durability problem, outworn facilities and insufficient parking area may be a main reason for reconstruction. It causes waste of national resources and makes recycling issues. Additionally, irregularly parked cars make traffic obstruction to a fire engine and result in many fire accident victims. Parking problems of apartments are not only inconvenience but also serious safety issues. From these points of view, remodeling only for parking area expansion is necessary to avoid overall reconstruction of apartments. The purpose of this study is to suggest a retaining wall selection method for apartments underground parking lots expansion without evacuation of resident people. Effect factors to select retaining wall system are analyzed and weight values are calculated by applying AHP. One selection method of retaining wall is proposed by evaluating applicability and its sensitivity analysis is executed. This selection method is expected to help decision-making of retaining wall system selection.

• Journal of the Korea Institute of Building Construction
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• v.11 no.4
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• pp.333-344
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• 2011

The recent expansion in the number of housing construction projects has been accompanied by substantial improvements in construction quality, which can be attributed to the development of new construction technologies and materials. In apartment complex construction projects, numerous mechanization technologies have been adopted as part of the floor plastering process to counter increasing difficulties in securing labor and the pressing need to reduce lead time, but these have also triggered setbacks such as additional costs or loss of time to fix cracks in or loosening of floor. Cracks developing in the floor of an apartment housing unit, in terms of materials in use, are the products of a complex combination of material makeup, construction workmanship, concrete curing and the protection method. Controlling such elements from the perspective of materials in use may ensure partial success in reducing cracks, but fall short of eliminating them completely. Any attempt to prevent cracks from developing in the first place requires systematic analysis as to their potential causes and viable solutions to reduce them. On this backdrop, this paper aims to provide an analysis of potential causes of cracks found in floor plastering, and consider the mechanism of a crack stop-bar as a fundamental safeguard against them.