• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.139-144
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• 2009

The generation of small hydropower as compared to other different developed environmental methods produces one of the clean energies. In such manner, various application system development through IT technique is being developed for an advanced small hydropower energy resources data mining. However, existing data analysis of New & Renewable Information System for small hydropower resources application is incomplete therefore it limits expressing these information on the Web. Thus for positive usage of small hydropower resources, a more systematic and precise analysis system should be built. This study seeks to develop a map of the domestic small hydropower resources problems to further improve small hydropower resources, developed through Package Tool which can accurately evaluate a wide range of small hydropower basin in a short period of time. Small hydropower Package Tool was calculated using existing Analysis System small hydropower resources which did not provide diverse capabilities resulting to 840 standard basin classified by A and facility capacity, etc., and to assume a 40% annual capacity, expected annual electricity production was calculated. Small hydropower for the national water system of small hydropower resources potential calculated in terms of resources for the development of small hydropower will be utilized as basic data.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.67-74
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• 1999

In this study, coda Q has been determined by the single scattering model in the Kyeongsang Basin region using the decay of the amplitudes of coda waves on bandpass-filtered seismograms of local microearthquakes in the frequency range 1.5~18 Hz. Reported frequency dependence of Q is of the form $Q_C=Q_O^n$$(83.9{ll}Q_0{ll}155.9,;0.76{ll}n{ll}1.05$. Considering a model incorporating both scattering and intrinsic attenuation, and assuming that the attenuation is entirely due to the scattering loss, the minimum mean free paths are about 51~56 km and the coefficients of inelastic attenuation(${\gamma}$) are between 0.0093 and 0.0098 were found. Earthquake-station paths pass through the fault zone show high attenuation and strong frequency dependency compared to other ones.

• Communications of Mathematical Education
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• v.27 no.1
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• pp.19-37
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• 2013

In order to improve the problem-solving abilities and enhance the academic achievement of under achieving students for university basic mathematics, P-university has opened the basic mathematics and practice education courses. These education courses are operated as prerequisite subject of Calculus and we are progressing the class focused on presentation with variety learning materials by organizing level-based classes In this paper, we analyzed the acquired grade and the result of teaching assessment of 1,106 students registered in the 30 classes that the teaching portfolio of the basic mathematics and practice education courses were submitted to support 'Accreditation for Engineering Education of Korea'. In addition, we tried to find attention points and improved solutions on operating the level-based class of the basic mathematics and practice education courses based on the 'Continuous Quality Improvement Report' of teaching portfolio submitted by each professor who is in charge of this class.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.3
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• pp.53-62
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• 2002

Site soil condition affects significantly on the seismic response of a structure and is a critical factor for the performance based seismic design of a structure. In this paper, the effects of nonlinear soil properties on the elastic response spectra of a structure including the nonlinearity of a soil due to the earthquake excitation is investigated using one step finite element approach for the entire soil structure system and approximate linear iterative procedure to simulate the nonlinear soil behavior with the Ramberg-Osgood soil model. Studies were carried out for a linear SDOF system of a variable period with and without a pile group for the 1940 CI Centro earthquake recorded on ground rather than rock. The study results showed clearly that the effect of the nonlinear behavior of soft soil is very important on the elastic seismic response of a structure suggesting the necessity of the performance based seismic design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1524-1530
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• 2016

Recently, research about an electronic attendance-absence recording system has been actively carried out using smart devices. Using an electronic attendance-absence recording system, professors can check their students' attendance on a real-time basis and manage their attendance records. In this paper, we proposed a real-time electronic attendance-absence recording system using face detection and face recognition based on web application. It can solve the spatial, temporal, cost issues belong to electronic attendance-absence recording system using AIDC(Automatic Identification and Data Capture). A proposed system is running on web server and made by HTML5(Hyper Text Markup Language ver.5). So professor connect to server using mobile web browser on mobile device and real-time manage electronic attendance-absence recording with real-time send or receive image data. In addition, the proposed system has an advantage capable of installation and operation, regardless of the operating system because it operates based on the Python flask framework.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.1
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• pp.73-79
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• 2001

In this study, a submerged plate-type breakwater is considered, which is supported by elastic foundation. This breakwater makes use of wave phase interaction among the incident, diffracted and radiated waves. We apply a three-dimensional singularity distribution method within the linear potential theory in order to describe the wave field. The submerged plate is assumed to be rigid and the elastic support be a linear spring with constant stiffness. A typical rectangle plate is exemplified for numerical calculation. The thickness of the plate is carefully selected in order to guarantee the solution to be stable by checking the condition number of the system matrix. A parametric study is carried out for examining the effect of the stiffness of the elastic support on performance of the breakwater. We also examine the effect of the submerged depth.

• Journal of Engineering Education Research
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• v.11 no.3
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• pp.70-77
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• 2008

This study investigates the level of the construction student's familiarity and interest in sustainability, their attitude toward sustainability, and the factors for bringing student's attitude toward sustainability. To accomplish the main objectives, this study employes a survey instrument created and developed by the authors. This is a descriptive and correlation study using responses from construction students at the Building Construction department at Virginia Polytechnic Institute and State University in Virginia. The results of descriptive statistics and multiple regression using SPSS version 16 present the following findings. Construction students perceive that they have a relatively high level of familiarity with sustainable construction and sustainability. Secondly, student's attitude toward sustainability is changed based on several factors such as sustainable construction courses, a professor who is interested in sustainability, their interest in the construction industry, university initiative, and the level of sustainability for student's learning facilities. Finally, the construction student's attitude toward sustainability can be improved by offering sustainable construction courses in construction programs, having professors who teach and research sustainability, and adopting sustainable initiatives at the university level such as campus recycling and various sustainable programs.

• Solar Energy
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• v.11 no.3
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• pp.62-73
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• 1991

The purpose of the present work is to investigate the atomization characteristics and to find the available working conditions of given nozzles. Experimental investigations were carried out with the nozzles, "Delavan" and "Hago"(pressure atomizing simplex 1.25GPH), with $60^{\circ}$ and $80^{\circ}$ spray angles also at various nozzle pressures. In the present work, Sauter mean-diameter was utilized to describe the quality of the atomization. All sample droplets were microphotographed with high-contrust film at 50X magnification and analyzed by Nukiyama-Tanazawa distribution function. The $80^{\circ}$ spray angle gives better atomization function than $60^{\circ}$ spray angle, and available working conditions were set at approximately $8kg/cm^2$ nozzle pressure.

• Geotechnical Engineering
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• v.13 no.1
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• pp.19-34
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• 1997

Applications of geostatistical method to cone penetrometer data have been performed at the overconsolidated clay site. Randomlylocated 28 electronic CPT soundings (Location A) and consistently-located 38 CPT soundings(Location B) are investigated geostatistically. Variograms for Locations A and B have been developed for q, from the CPT data by using "kriging" principles, which establish the horizontal and vertical correlation distrances at this site. These vertical and horizontal correlation distances can be used to optimal sampling design, where, if one needs to compare two test results, sampling must be made within these vertical and horizontal correlation distances. Analysis of the variograms indicated that the geological formation between two locations are not very different in both vertical direction and horizontal direction.direction.

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.99-110
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• 1999

The method of moments, a Lagrangian scheme, considers the zeroth, first, and second moments of the grid cell spatial distributions of the concentration and then advects the concentration by maintaining conservation of the moments. The reasonable inital description of the first and second moments as well as the mean concentration, the zeroth moments, in grid element is important in the method of moments. In this study, the description methods of each initial moment are reviewed, and the method of moments is extended to overcome the restrictions of Courant number. Its performance is compared with those of available Eulerian and Lagrangian schemes. As the results, the method is successfully extended to overcome the stability restriction and is an accurate scheme for the advection simulation of concentration distribution, especially of which the gradient is steep. In addition, the method is very promising scheme in terms of computational efficiency when the mixing is confined in a relatively small region to the entire domain in two-dimensional problem.