• Journal of Korean Society of Rural Planning
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• v.26 no.1
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• pp.77-88
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• 2020

This study had comparatively analyzed the influence factors of the farm village business on the local farmhouses centered on the level of importance and the level of performance. For this, a questionnaire survey had been conducted with 350 local residents who had participated in the Rural Field Forum of 14 villages, including Gyeongsangnam-do, Gyeongsangbuk-do, Chungcheongnam-do, Chungcheongbuk-do, Jeollabuk-do, etc. Excluding the insincere survey questionnaires, the final 232 people had been analyzed. As a result of the analysis of this study, the factors that have the influences on the diverse, rural areas had been compressed into the three factors of the lodging and the program, the special, rural area products, and the transportation and the accessibility. In the level of importance-level of performance analysis, it had been analyzed that the special, rural area products must maintain the continuity, that the transportation accessibility must avoid the excessive endeavor, and that the lodging program had a low priority order. Therefore, it can be said that it is necessary to concentrate the capability of the rural village business in the direction of developing the local specialties in the future. Next, after dividing the level of performance and the level of importance into the two groups each, the multiple group path analysis had been carried out. As a result, in the result of the analysis of the path that has an influence on the economic factor, the path coefficient of the level of importance of the transportation accessibility -> profit increase was 0.195+0.064 and the path coefficient of the level of performance of the transportation accessibility -> profit increase was 0.251+0.074. Therefore, both of them had the statistically significant amounts of the influences. This suggests that the transportation accessibility is an important element of the profit increase of the region. As a result, in the future, the research on the urban and rural exchanges using the even more convenient and inexpensive transportation means is needed. Most of them need the voluntary effort of the residents for being able to creatively develop and sell the native, agricultural, specialty products that are petty. Also, the rural areas need the diversities of the lodging programs and the recreational programs, a convenient reservation system, and the development of a unique tourism experience program. In the future, the researches that had been advanced in the even more detailed domain that is related to these factors are highly expected. Also, the analyses that had been carried out with even more areas and subjects as the targets are needed.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.398-405
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• 2001

The rivet joint has typical structural feature that can be initiation site for the fatigue crack due to the combination of local stress concentration around rivet hole and the moisture trapping. From a viewpoint of structural assurance, it is crucial to evaluate the size of crack around the rivet holes by appropriate nondestructive evaluation techniques. Lamb wave that is one of guided waves, offers a more efficient tool for nondestructive inspection of plates. The neural network that is considered to be the most suitable for pattern recognition has been used by researchers in NDE field to classify different types of flaws and flaw sizes. In this study, clack size evaluation around the rivet hole using the neural network based on the back-propagation algorithm has been tarried out by extracting some features from the ultrasonic Lamb wave for A12024-T3 skin panel of aircraft. Special attention was paid to reduce the coupling effect between the transducer and the specimen by extracting some features related to time md frequency component data in ultrasonic waveform. It was demonstrated clearly that features extracted from the time and frequency domain data of Lamb wave signal were very useful to determine crack size initiated from rivet hole through neural network.

• The Korean Journal of Petroleum Geology
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• v.1 no.1 s.1
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• pp.47-52
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• 1993

A method and results of computations are presented for the 2-D seismic migration process in the frequency-wavenumber domain for the laterally and vertically inhomogeneous medium. In order to take the intrinsic attenuation effect into account in the migration process the complex-valued wave velocity is used in the wavefield extrapolation operator, improving the generalized frequency-wavenumber migration technique. The imaginary part of the complex-valued wave velocity includes the seismic quality factor Q value. In derivation of the solution of the wave equation for the medium of inhomogeneous wave velocity and anelasticity, the inhomogeneous medium is mathematically converted to an equivalent system which consists of a homogeneous medium of averaged slowness and an inhomogeneous distribution of hypothetical wave source. The strength of the hypothetical wave source depends on the deviation of squared slowness from the averaged value of the medium. Results of numerical computation using the technique show more distinct geologic images than those using the convensional generalized frequency-wavenumber migration. Especially, the obscured images due to the wave attenuation by anelasticity are restored to show sharp boundaries of structures. The method will be useful in the imaging of the reflection data obtained in the regions of possible petroleum or natural gas reservoir and of fractured zone.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.17-18
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• 2011

Plasma in liquid phase has attracted great attention in the last few years by the wide domain of applications in material processing, decomposition of organic and inorganic chemical compounds and sterilization of water. The plasma in liquid is characterized by three main regions which interact each - other during the plasma operation: the liquid phase, which supply the plasma gas phase with various chemical compounds and ions, the plasma in the gas phase at atmospheric pressure and the interface between these two regions. The most complex region, but extremely interesting from the fundamental, chemical and physical processes which occur here, is the boundary between the liquid phase and the plasma gas phase. In our laboratory, plasma in liquid which behaves as a glow discharge type, is generated by using a bipolar pulsed power supply, with variable pulse width, in the range of 0.5~10 ${\mu}s$ and 10 to 30 kHz repetition rate. Plasma in water and other different solutions was characterized by electrical and optical measurements. Strong emissions of OH and H radicals dominate the optical spectra. Generally water with 500 ${\mu}S/cm$ conductivity has a breakdown voltage around 2 kV, depending on the pulse width and the repetition rate of the power supply. The characteristics of the plasma initiated in ultrapure water between pairs of different materials used for electrodes (W and Ta) were investigated by the time-resolved optical emission and the broad-band absorption spectroscopy. The deexcitation processes of the reactive species formed in the water plasma depend on the electrode material, but have been independent on the polarity of the applied voltage pulses. Recently, Coherent anti-Stokes Raman Spectroscopy method was employed to investigate the chemistry in the liquid phase and at the interface between the gas and the liquid phases of the solution plasma system. The use of the solution plasma allows rapid fabrication of the metal nanoparticles without being necessary the addition of different reducing agents, because plasma in the liquid phase provides a reaction field with a highly excited energy radicals. We successfully synthesized gold nanoparticles using a glow discharge in aqueous solution. Nanoparticles with an average size of less than 10 nm were obtained using chlorauric acid solutions as the metal source. Carbon/Pt hybrid nanostructures have been obtained by treating carbon balls, synthesized in a CVD chamber, with hexachloro- platinum acid in a solution plasma system. The solution plasma was successfully used to remove the template remained after the mesoporous silica synthesis. Surface functionalization of the carbon structures and the silica surface with different chemical groups and nanoparticles, was also performed by processing these materials in the liquid plasma.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.247-256
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• 2014

Recently, camera and RADAR are used for more effective and accurate observation of the bird migration. In recent years, many researches on the bird migration using RADAR are undertaking and in active, thus causes the advent of "RADAR ornithology" as a new academic field. Due to the lack of accessibility, economic feasibility and mobility of weather RADAR, airport searching RADAR and tracking RADAR, Nowadays, a marine RADAR is widely used for a bird observation. In this paper, we deals with a study on development of a remote bird observation system using marine FMCW RADAR, which monitors, records and analyzes bird movement by RADAR image processing and target recognition technology. Also, we conduct first test and second test for availability of the developed system, and verify the system to apply in bird observation domain. Consequently, we figured problems out, and correct the problems to improve the system. The developed system can apply in other domains such as environment evaluation. In the future, the system needs to improve accuracy of statistics and to track migration route of bird.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.271-285
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• 2020

In this study, a numerical experiment related to the stress-strain analysis was performed on 3-D discrete fracture network(DFN) systems based on the distinct element method to evaluate the effect of joint geometry on deformability of jointed rock masses. Using one or two joint sets with deterministic orientation, a total of 12 3-D DFN blocks having 10m cube domain were generated with different joint density and size distribution. Directional deformation modulus of the DFN cube blocks were estimated along the axis directions of 3-D cartesian coordinate. In addition, deviatoric stress directions were chosen at every 30° of trend and plunge in 3-D for some DFN blocks to examine the variability of directional deformation modulus with respect to joint geometry. The directional deformation modulus of the DFN block were found to reduce with the increase of joint size distribution. The increase in joint density was less likely to have a significant effect on directional deformation modulus of the DFN block in case of the effect of rock bridges was relatively large because of short joint size distribution. It, however, was evaluated that the longer the joint size, the increase in the joint density had a more significant effect on the anisotropic deformation modulus of the DFN block. The variation of the anisotropic deformation modulus according to the variations in joint density and size distribution was highly dependent on the number of joint sets and their orientation in the DFN block. Finally, this study addressed a numerical procedure for stress-strain analysis of jointed rock masses considering joint geometry and discussed a methodology for practical application at the field scale.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.234-246
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• 2007

The role of macropore in the hydrological processes is important at the hillslope scale. Developments and distribution of macropores have not been investigated in conjunction with the characteristics of the hillslope such as topography, soil property, and soil moisture. In this study, macropore properties, such as macropore flow and saturation hydraulic conductivity were measured at a hillslope located in Gwangneung Research Forest, Pochun-gun, Gyeonggi-do, South Korea. An intensive field survey provided a refined Digital Elevation Model (DEM) for surface and subsurface topography. Spatial distributions of upslope area and topographic index were obtained through the digital terrain analysis. The total number of monitoring points was 22, and the selected points were distributed along the transect of the digital contour map. Vertical fluxes through macropores were measured using a tension infiltrometer at the depth of 0.1 m from the surface. Spatial and temporal distributions of soil moisture were obtained using an on-line measurement system, TRASE, installed in the study area. Soil moisture for the aforementioned points was measured at 0.1 and 0.3m depths below the surface. The results from tension infiltrometer experiments present that the macropore flows ranged between 21 and 94%, and the measured macroporosities varied from 1.4 to 47%. Macropore flows and macroporosities tended to increase as the measurement location moved to downslope. The ability for water conduction through macropores becomes increasingly developed as the location approaches the outlet of the hillslope.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.92-100
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• 2011

This paper describes a numerical modeling for deflection calculation using the natural frequency response that is measured acceleration response for concrete bridges. In the formulation of the dynamic deflection, the change amounts and the transformed responses about six kinds of free vibration responses are defined totally. The predicted response can be obtained from the measured acceleration data without requiring the knowledge of the initial velocity and displacement information. The relationship between the predicted response and the actual deflection is derived using the mathematical modeling that is induced by the process of a acceleration test data. In this study, in order to apply the proposed response predicted model to the integration scheme of the natural frequency domain, the Fourier Fast Transform of the deflection response is separated into the frequency component of the measured data. The feasibility for field application of the proposed calculation method is tested by the mode superposition method using the PSC-I bridges superstructures under several cases of moving load and results are compared with the actually measured deflections using transducers. It has been observed that the proposed method can asses the deflection responses successfully when the measured acceleration signals include the vehicle loading state and the free vibration behavior.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.639-662
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• 2012

The purpose of this study is to develop the evaluation model of gifted curriculum in visual art. For this purpose, first, it discusses about what kinds of issues raised about gifted education in visual art. Second, it critically reviews the evaluation models of gifted curriculum, and investigates the suitable model for developing curriculum evaluation model of gifted in visual art. Third, it suggests the appropriate perspective and evaluation model of gifted curriculum in visual art. Along with the change in the concept of creativity, recent studies on gifted education in visual art concentrate that gifted learners who have the potential find their own way of creating art. Also they emphasize the contextual implementation which recognizes the significance of interaction among field, domain and individual. Based of these inquiry, existing evaluation models of gifted curriculum have limitations in suitability as a evaluation model of gifted curriculum in visual art. This study suggests that the curriculum evaluation of visual art gifted programs should be approached from the decision-making perspective. Also it develops the conceptual framework and the evaluation model of gifted curriculum in visual art based on the CIPP model, which is the representative model of decision-making approach. It concludes with its implications and the discussion about the role of evaluators.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.79-89
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• 2013

ATCIS (Army Tactical Command Information System) provides commanders and staff officers the battlefield information that is reported by tactical echelons under an army corps and the commanders make decisions based on the information by using their experience and specialty in military domain. If ATICS can automatically understand the reported information from rapidly changing battlefield and provide new knowledge that can support decision making, the commanders would be able to make faster and more accurate decision. In this paper, therefore, we propose an intelligent ATCIS using a national defense ontology. To this end, we built the national defense ontology by analyzing the electronic field manuals and ATCIS database, and then we defined military knowledge for decision making as a form of rule by interviewing several staff officers from different fields. In order to show how to apply the ontology and rules to decision making support for the commanders, we implemented a decision support service to estimate the possibility of enemy's provocation by using semantic web technologies.