• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.141-144
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• 2005

• Economic and Environmental Geology
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• v.47 no.3
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• pp.265-273
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• 2014

Unconventional resources are natural resources which require greater than industry-standard levels of technology or investment to exploit the commercial development. The key point is that unconventional resources are lower quality fuel sources and are not as economically viable as crude oil and conventional gas. Over the past 100 years, Conventional oil and gas has been satisfied with the energy demands. But developing countries such as China and India, the introduction of the developed countries and the surge of energy due to the depletion of unconventional energy resources will be the limelight. According to be analyzed in the academic literature to unconventional gas and oil(2000~2012) by the program of 'web of science', the research activities 402 papers in unconventional gas and 1,581 papers in unconventional oil.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.143-148
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• 2004

고로슬래그 미분말과 플라이 애쉬와 같은 재료들이 콘크리트의 내구성과 장기강도 증진을 목적으로 혼합재로서 사용되고 있다. 본 연구에서는 고로슬래그 사용 몰탈의 내구성 증진 특성을 활용하기 위하여 고로슬래그 미분말에 알칼리 자극제를 첨가한 알칼리 활성화 슬래그계 무기결합재 사용 몰탈의 내구성과 물리적 특성을 평가하였다. 실험결과, 몰탈의 초기 압축강도 발현에 알칼리 자극제가 큰 영향을 미치는 것을 확인하였다. 또한 알칼리 자극제가 첨가된 몰탈의 화학적 저항성을 평가하기 위하여 공시체를 재령 28 일 후, 5% 황산($H_2SO_4$) 용액에 침지하여 압축강도 및 질량 변화를 관찰하였다. 그 결과, 보통포틀랜드 시멘트로 제조한 몰탈의 경우, 황산용액 침지 후 압축강도가 54% 감소하였다. 반면 고로슬래그 미분말을 첨가한 몰탈의 경우, 약 10% 강도가 감소하였다. 질량변화의 경우, 보통포틀랜드 시멘트로 제조한 공시체는 17%, 고로슬래그 미분말을 첨가한 몰탈은 3%의 질량변화를 보였다. 이 결과로서 고로슬래그 미분말을 첨가한 몰탈의 경우, 화학적 저항성과 물리적 특성이 우수한 것을 확인하였다.

• Geophysics and Geophysical Exploration
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• v.26 no.3
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• pp.114-125
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• 2023

The physics-informed neural network (PINN) has been proposed to overcome the limitations of various numerical methods used to solve partial differential equations (PDEs) and the drawbacks of purely data-driven machine learning. The PINN directly applies PDEs to the construction of the loss function, introducing physical constraints to machine learning training. This technique can also be applied to wave equation modeling. However, to solve the wave equation using the PINN, second-order differentiations with respect to input data must be performed during neural network training, and the resulting wavefields contain complex dynamical phenomena, requiring careful strategies. This tutorial elucidates the fundamental concepts of the PINN and discusses considerations for wave equation modeling using the PINN approach. These considerations include spatial coordinate normalization, the selection of activation functions, and strategies for incorporating physics loss. Our experimental results demonstrated that normalizing the spatial coordinates of the training data leads to a more accurate reflection of initial conditions in neural network training for wave equation modeling. Furthermore, the characteristics of various functions were compared to select an appropriate activation function for wavefield prediction using neural networks. These comparisons focused on their differentiation with respect to input data and their convergence properties. Finally, the results of two scenarios for incorporating physics loss into the loss function during neural network training were compared. Through numerical experiments, a curriculum-based learning strategy, applying physics loss after the initial training steps, was more effective than utilizing physics loss from the early training steps. In addition, the effectiveness of the PINN technique was confirmed by comparing these results with those of training without any use of physics loss.

• Journal of the Korean association of regional geographers
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• v.16 no.3
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• pp.315-323
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• 2010

The purpose of this study was to investigate the relationship between the determinant factors of visitors' satisfaction and behavioral intentions to the Shincheon stream in Daegu city. It was found that ecology of the Shincheon stream, signals about ecology, and physical facilities positively influenced overall satisfaction. Physical facilities more positively influenced overall satisfaction. The overall satisfaction positively influenced behavioral intentions. For the future studies, it is necessary to do research visitors' satisfaction with more diverse factors of satisfaction and longitudinal studies about visitors' satisfaction based on seasonally different visitors.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.2
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• pp.118-127
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• 2013

In this study, Seongbuk-dong historical & cultural resources of the surrounding landscape were analyzed by the visual characteristics of the landscape adjective analysis. Research was investigate to the relationship between visual characteristics and preferences and Research in the following way. Selected historical and cultural resources in the surrounding area are located in Seongbuk-dong 30 slices the survey was conducted. Landscape preference factors to identify the scale of 16 adjectives and then factor analysis was conducted. Lastly, Analysis of variance and regression analysis were conducted in order to determine the impact of the last image factors on visual preferences. Firstly, The results can be summarized as follows. Officer for 30 pictures appear in Seongbuk-dong in the historical and cultural resources, and distributed around the target preference for the 16 adjectives analysis yielded an average result of overall preference were analyzed and that is a 3.72 average. In these photos, VP8, VP9, VP10, VP12, VP15; 4.5 points more than one order higher. The reason is limit of altitude by the Seoul landscape plan for the historical and cultural resources around. It also judged important reason that history and Culture are in harmony with the surrounding cultural property in the conservation area. Secondly, Important factors are factor 1(aesthetic factors), factor 2(cultural factors), factor 3(physical factors) and three factors could be identified. Results of the analysis of variance and regression analysis about factors for visual preference and image shows value of psychological factor is most significant to explain for nearby history &cultural resources of Seongbuk-dong of scenery around. As a result, the state can not view historical and cultural resources for analysis will be located in a residential area near the historical and cultural resources for aesthetic factors. Third, the negative side of the argument is a residential area which is not arranged surrounding landscape maintenance of historical and cultural resources has emerged. Historical and cultural resources in harmony with the phenomena of the physical, cultural, and aesthetic characteristics of the three areas is a positive factor in the high incidence. Factors from that are expressed in this study by analyzing multi-dimensional analysis to derive a factor to be considered important in the management of historical and cultural resources, landscape around is required.

• Geophysics and Geophysical Exploration
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• v.24 no.1
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• pp.20-27
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• 2021

Subsurface rock produces heat from the decay of radioactive isotopes in constituent minerals and gamma-ray emissions, of which the magnitude is dominated by the contents of the major radioactive isotopes (e.g., U, Th, and K). The heat production is generally calculated from the rock density and contents of major isotopes, which can be determined by mass spectrometry of drilled core samples or rock fragments. However, such methods are not easily applicable to deep boreholes because core samples recovered from depths of several hundred meters to a few kilometers are rarely available. A geophysical logging technique for boreholes is available where the U, Th, and K contents are measured from the gamma-ray spectrum. However, this technique requires the density to be measured separately, and the measurement depth of the equipment is still limited. As an alternative method, a normal gamma-ray logging tool was adopted to estimate the heat production from the total gamma activity, which is relatively easy to measure. This technical report introduces the development of the proposed method for evaluating the heat production of a granitic rock mass with domestic commercial borehole logging tools, as well as its application to a ~2 km deep borehole for verification.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.348-355
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• 2021

Asphalt, widely used for road pavement, has different required physical properties depending on the environment to which the road is exposed. Therefore, it is essential to maximize the life of asphalt roads by evaluating the physical properties of asphalt according to additives and selecting an appropriate formulation considering road traffic and climatic environment. Dynamic shear rheometer(DSR) test is mainly used to measure resistance to rutting among various physical properties of asphalt. However, the DSR test has limitations in that the results are different depending on the experimental setting and can only be measured within a specific temperature range. Therefore, in this study, to overcome the limitations of the DSR test, the rheological characteristics were predicted by learning the images collected from atomic force microscopy. Images and rheology properties were trained through EfficientNet, one of the deep learning architectures, and transfer learning was used to overcome the limitation of the deep learning model, which require many data. The trained model predicted the rheological properties of the asphalt binder with high accuracy even though different types of additives were used. In particular, it was possible to train faster than when transfer learning was not used.

• Review of KIISC
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• v.14 no.5
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• pp.50-58
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• 2004

컨텍스트 인식과 적응에 더불어 유비쿼터스 컴퓨팅 실현의 필수 요소는 보안이다. 유비쿼터스 환경에서 자원과 서비스는 응용이 실행되는 지역에 있을 수도 있지만 대게는 물리적으로 분산된 환경 안에 존재하게 된다. 유비쿼터스 환경은 응용이 실행되는 환경에서의 보안은 물론이고 분산 환경에서의 자원과 서비스에 대한 보안도 필수적으로 고려되어야 한다. 유비쿼터스 컴퓨팅의 새로운 취약점을 다루기 위해 유비쿼터스 컴퓨팅 환경의 보안은 미들웨어의 추가사항으로 고려되는 것보다는 미들웨어의 설계단계에서부터 고려되어야한다. 또한 유비쿼터스 환경에서 응용과 서비스는 미들웨어에 항상 고정되어 있는 것이 아니라 동적으로 결합되고 분리되므로 사용자가 실행한 응용이 신뢰할 수 있는지와 그 응용이 이용하려고 하는 서비스에 대해 접근 권한이 있는지는 중요하다. 기존의 유비쿼터스 미들웨어는 동적으로 변하는 컨텍스트에 대해 응용이 잘 적응 할 수 있는 구조로는 되어있지만 응용이 이용하려는 서비스에 접근 권한이 있는지에 대해서는 조사하지 않기 때문에 서비스는 여러 보안위협에 대해 안전할 수 없다. 본 논문은 유비쿼터스 환경에서 편재된 자원과 서비스를 사용하는 프로그램의 실행여부를 접근통제 관점에서 분석하고 유비쿼터스 보안 미들웨어의 접근통제 기능에 대해 고찰한다.

• KNOM Review
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• v.22 no.3
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• pp.25-30
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• 2019

For meteorological applications, meaningful results must be derived and provided within time and resource limits. Forecasts through numerous historical data are time-consuming and still have resource limitations in the case of disaster safety-related analyses/predictions such as local typhoon forecasts. Suitable forecasts should be provided without any problems caused by limited physical environmental conditions and when results are to be drawn under time constraints, such as typhoon forecasts and forecast services for flooded areas by road. In this paper, we analyze the application of weather and climate forecasting to provide a suitable forecasting service in both temporal and resource conditions. Through the analysis of execution time according to mesh sizes, it was confirmed that a mesh adjustment can cope with the case of the temporal constraint. In addition, by analyzing the execution time through memory resource control, we confirmed the minimum resource condition that does not affect the performance and the resource usage pattern of the application through the swap and mlock analysis.