• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.76-82
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• 1997

The paper describes simulations and experimental results using a measuring system which utilizes the acoustic holographic method in order to exactly estimate an absolute position of a sound source. The measuring surface is installed to satisfy with a far field to the sound source and is composed of linear arrayed seven microphones. A measurement is simultaneously recorded by a reference microphone setting up a neighbour sound source and the linear arrayed seven microphones which are moved to the same interval. An absolute position of sound source is estimated by the cross-spectrum method to the received sounds between a reference and the measuring microphones. Phase differences of each microphone and time delays during scanning are compensated to the reference microphone and the measuring time of the first column. An optimal interval for each microphone in the measuring surface is decided by a numerical simulation. A source signal makes use of a sinusoid, and S/N ratio is 30dB in the experiment. The optimal microphone's interval in the simulation and the experiment is decided in order to satisfy with the Nyquist space sampling condition related to the wave length of 2kHz sinusoid. Mainlobe width of a estimated 3D hologram in the case of 2kHz source signal is decreased to 87% and 30% in comparison to 500Hz and 1kHz, and then a valid of simulation results is confirmed. Therefore, we verified a utilization of the study for a sound source estimation using 3ㅇ acoustic holographic method.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.759-769
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• 2008

Convergence technology stimulating participation sharing openness to the public of web 2.0 such as Open-API, Mash-Up, Syndication gives diversity to education field. The convergence in education field means the revolution toward education 2.0 and new education reflecting web 2.0 stream is called 'education 2.0'. Education environment can be the space of social network intimately linked between learners, educators and educational organization. Network technology developed in ontology language makes it possible to educate semantically which understands privatized education service and connection. Especially, filtering system by the reputation system of Amazon and the collective intelligence of Wikipedia are the best samples. Education area can adopt actively because learners as educational main body can broaden their role of participation and communicate bilaterally in the equal position. In this paper, new network architecture in contents linkage is introduced and researched for utilization and analysis of the architecture for web 2.0 technology and educational contents are to be converged. Education 2.0 service utilizing convergence technology and network architecture for realizing education 2.0 is introduced and analyzed so that the research could be a preceding research to the education 2.0 platform foundation.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.607-613
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• 2006

For the reasonable use of low grade-shallow geothermal energy by Standing Column Well(SCW) system, the basic requirements are depth-wise increase of earth temperature like $2^{\circ}C$ per every 100m depth, sufficient amount of groundwater production being about 10 to 30% of the design flow rate of GSHP with good water quality and moderate temperature, and non-collapsing of borehole wall during reinjection of circulating water into the SCW. A closed loop type-vertical ground heat exchanger(GHEX) with $100{\sim}150m$ deep can supply geothermal energy of 2 to 3 RT but a SCW with $400{\sim}500m$ deep can provide $30{\sim}40RT$ being equivalent to 10 to 15 numbers of GHEX as well requires smaller space. Being considered as an alternative of vertical GHEX, many numbers of SCW have been widely constructed in whole country without any account for site specific hydrogeologic and geothermal characteristics. When those are designed and constructed under the base of insufficient knowledges of hydrgeothermal properties of the relevant specific site as our current situations, a bad reputation will be created and it will hamper a rational utilization of geothermal energy using SCW in the near future. This paper is prepared for providing a guideline of SCW design comportable to our hydrogeothermal system.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.237-248
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• 2013

Hybrid broadcasting environment is convergence of broadcasting and communication environment. In hybrid broadcasting environment, a number of media can be delivered using both broadcasting channel and other network unlike traditional broadcast environment that is able to deliver a couple of media by the limited bandwidth. Now, starting with smart TV, hybrid broadcasting environment combining broadcasting channel and IP network is established, and a variety of services are appearing. Moreover, the services using hybrid broadcasting environment are expected to appear soon for the other smart terminals such as smart phone and tablet PC. Scene composition is one of the methods that can consume effectively a number of media delivered from hybrid broadcasting environment. Using scene composition, multiple media can be consumed through the specified presentation time and space. Therefore, in this paper, it proposes the scene composition technology that is suitable for hybrid broadcasting environment and smart terminals. However, the spatial composition and temporal composition of media using script language and style language of HTML5 might increase the complexity of processing, and cause limitation of avaliable terminals. Also, a document of HTML5 can describe only one scene. By these reason, the proposed scene composition technology extends HTML5 in order to provide the spatial and temporal composition of media and description of multiple scene through markup language. In addition, it includes the extension of HTML5 in terms of utilization in hybrid broadcasting environment. For this proposal, this paper describes the technology of HTML5 and proposed scene composition. Also, it verifies the scene composition with both implementations and experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.269-278
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• 2018

In Korea, BIM technology is applied mainly to building construction projects, but is expected to be applied rapidly to civil engineering projects because the government is currently considering the mandatory application of BIM for infrastructure facilities. Because the infrastructure project is processed in a horizontal work area, the application of BIM technology is more useful in the schedule management of the construction phase than the interference management of the design phase. The 4D CAD system is a typical BIM technology applied to the schedule management in the construction phase, but the application to the actual project is limited due to the lack of practical functions. This study examined the functions of four representative 4D CAD systems commercialized so that the selection criterion can be provided according to the characteristics of the project, and suggests that the functions that should be improved to have practicability. As a result of functional analysis, the application characteristics of each system were analyzed and the user convenience was suggested. In addition, a linear 4D simulation methodology was developed to improve the functions applicable to civil engineering projects, and ways to improve the utilization of the infrastructure projects as the construction phase BIM were suggested. In railway and road construction projects, most activities, such as earthwork, bridges, and tunnels proceed along the distance axis in a horizontal space. Therefore, a linear 4D simulation method, in which an activity is expressed along a distance axis, can be more practically useful rather than a simple 4D simulation method with a Gantt chart.

• Journal of Distribution Science
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• v.12 no.12
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• pp.101-106
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• 2014

Purpose - This study reviews the achievements of a pilot project for the revitalization of a commercial district performed for three years after its establishment in 2011. The project for the revitalization of the commercial district was performed to create a new local community space in connection with the traditional market and nearby districts. Although it was a pilot project, the project for the revitalization of the commercial district has been performed for almost three years. Therefore, this seems a proper time to conduct an interim evaluation of the project. This study aims to review and evaluate how the government support policy is influential for the revitalization of the commercial district. In other words, this research aims to identify what projects positively affected consumers' intention to revisit the downtown commercial area among the commercial district revitalization projects-promotion events, promotion activities, education, merchants cooperation system, IT projects, cultural events, and residents' communication. Research design, data, and methodology - This study designated seven management improvement projects affecting commercial district revitalization based on preceding studies. The survey of the degree of satisfaction on seven management improvement projects was executed targeting consumers who visited the commercial areas. Additionally, visitors' revisit intentions regarding currently visited commercial areas were also investigated. Therefore, revisit intention was set as a dependent variable and the satisfaction degrees of the respective management improvement projects were set as the independent variables. A total of 1,209 consumers were examined in six districts in the country. Result - Multiple regression analysis results showed that cultural events, education, the merchants' cooperation system, and IT projects brought statistically significant effects to the revisit intentions of consumers. In contrast, promotion events, resident communication projects, and promotion activities did not affect the revisit intentions of consumers. Particularly, the residents' communication project did not show significant influence because of consumers' recognition that it is similar to a cultural event. Conclusion - The following implications for the revitalization of business districts in the urban central area are drawn. From a general perspective, the businesses of culture, education, and cooperative system among seven businesses play positive roles regarding the intention to revisit so that the project is required to be promoted periodically through unique performances differentiated for each district, the merchant training reinforced for professionalism, and the expansion of joint events of merchants. Moreover, the sales promotion project and public relations activity are shown to be not influential to the intention to revisit. Therefore, while short-term sales promotion such as one-time gift events are required, sales promotion and public relation activities to induce revisits by mileage savings and accumulated gift presentation to attract long-term customers are required. The IT business is positively influential to the intention of revisit. Therefore, detailed information on the revitalized commercial district should be provided and additional functions such as discount coupons for continuous utilization should be included in the mobile app and the website.

• Tunnel and Underground Space
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• v.22 no.6
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• pp.412-428
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• 2012

To achieve mine development, a large amount of data concerned with the geological structure and the ore body had to be investigated and collected through geological survey, drilling and geophysical explorations. In most previous cases, however, the data were usually analyzed two dimensionally and those results showed some limits because of their 2D presentation. Those 2D maps such as geological plane sections or longitudinal sections cause lots of difficulties in understanding the complex geological structure or the feature of ore body in a spatial way. In this study, research area was set on the abandoned Yangyang iron mine in Korea and the Sugaeng ore body within the mine was selected as the research target to design a mine haulage system for reopening. A 3D mine model of this area was tried to be constructed using a 3D modelling software, GEMS. An accurate 3D model including the ore body, the geological structure, the old underground mine drifts and the new mine drifts was constructed under the purpose of reopening of the abandoned iron mine. Especially, mine design for trackless haulage system was conducted. New inclines and drifts were planned and modelled 3 dimensionally considering the utilization of old drifts and shaft. In addition to the 3D modelling, geostatistical technique was adopted to generate a spatial distribution of the ore grade and the rock physical properties. 3D model would be able to contribute in solving problems such as evaluating ore reserves, planning the mine development and additional explorations and changing the development plans, etc.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.133-137
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• 2012

Among various clean energy technologies, the solar energy technology has been widely used in various fields such as photovoltaic power generation and solar water/space heating. These days, special attention is drawn on its conversion into acoustic energy along with waste heat as a means to promote clean energy utilization. This work was carried out to investigate the possibility of converting solar energy into acoustic waves, especially, its performance characteristics for a single resonance tube (20.2 mm in ID). Variations are made for the stack length and its position as well as power supply. For a resonance tube of 200mm, an average sound pressure of 114.5 dB was measured with a stack length of 25.6mm at 5cm from the closed end. When the power supply was increased to 35W, an average sound pressure of 117.29 dB was detected with a frequency of 500Hz. There was an increase in frequency, 630 Hz (115.7dB), with a shorter resonance tube of 150mm.

• Journal of Environmental Impact Assessment
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• v.25 no.1
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• pp.25-40
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• 2016

This study suggests direction of new ordinance establishment for the future national application of Low Impact Development(LID) by analyzing current LID-related regulations of local governments, substantial agents to install and maintain a facility, through qualitative and quantitative methodologies. Four key words related to LID were derived from advisory conference and then ninety nine ordinances as the LID-related regulations were extracted to analyze. The study shows that rainwater-related ordinance passed in the middle of 2000s are being merely converted to the law on the promotion and support of water reuse. Regulations on water cycle and LID exist only in three cities nationwide(Seoul City, Suwon City and Namangju City). Interview with administrators of three cities to have LID-related regulations revealed following results. First, both rainwater and water reuse related regulations have not considered regional characteristics such as rainfall intensity, effects of impervious and merely followed guidelines by Ministry of Government Administration and Home Affairs. Second, existing ordinance is confined to specific facilities and thus cannot include the concept of LID which covers land and space utilization. Therefore, for proper application of LID, this study proposes issue of ordinance that resembles Seoul City ordinance and a new guideline that can reflect regional characteristics such as rainfall and location.

• Journal of Korean Society of Rural Planning
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• v.23 no.3
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• pp.163-174
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• 2017

This study developed the prototype of the system and implemented its main functions, which is the intelligent integrated agricultural water management information system and service (IaWAMISS). The developed system was designed to be able to collect, process and analyze the agricultural water information of spatially dispersed reservoirs in whole country and spatial geographic information distributed in various systems of other organizations. The system, IaWAMISS, is also possible to provide the reproduced information services in each reservoir and space units, such as agricultural water demand and supply analysis and drought prediction, to the people, experts, and policy makers. This study defined the 6 step modules to develop the system, which are to design the components of intelligent integrated information system, to derive the utilization contents of existing systems, to design the new development elements for IaWAMISS, to design the reservoir information system can be used by managers of city and county, to designate the monitoring reservoirs managed by city and county, and finally to prepare the sharing system between organizations with the existing information systems. In order to implement the prototype of the system, this study shows the results for three important functions of the system: spatial integration of reservoirs' information, data link integration between the existing systems, and intelligent analysis program development to assist decision support for agricultural water management. For the spatial integration with the reservoir water information of the Korea Rural Community Corporation, this study get IaWAMISS to receive the real-time reservoir storage information from the measurement facility installed in the municipal management reservoir. The data link integration connecting databases of the existing systems, was implemented by integrating the meteorological information of the Korea Meteorological Administration with IaWAMISS, so that the rainfall forecast data could be derived and used. For the implementation of the intelligent analysis program, this study also showed the results of analysis and prediction of agricultural water demand and supply amount, estimation of Palmer drought index, analysis of flood risk area in typhoon course region, and analysis of the storage status of reservoirs related to each storm. This study confirmed the possibility and efficiency of an useful system development through the prototype design and implementation of IaWAMISS. By solving the preliminary 6 step modules presented in this study, it is possible not only to efficiently manage water by spatial unit, but also to provide the service of information and to enhance the relevant policy and national understanding to the people.