• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.620-628
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• 2021

The article is devoted to studying the development of scientific and methodological work and its impact on the quality of students' vocational training in higher pedagogical education institutions by applying information technology. The article aim is to development of the organizational methodological support and pedagogical diagnostics of the effectiveness of the project «Modelling scientific and methodological work in a higher education pedagogical institution by applying information technology » realization in the framework of increasing the level of scientific and methodological work in a higher education pedagogical institution as a factor contributing to enhancing the quality of pedagogical education. The research program of the project activity envisages stating and substantiating the problem of scientific and methodological work by applying information technology in the framework of increasing the level and quality of educational activities in a higher pedagogical education institution through the implementation of the project approach, developing a model for the system of organizational and methodological support of the project implementation as well as monitoring the process and evaluating the results of the project implementation in terms of developing teachers' scientific, methodological, information competency and enhancing students' progress in studying. The set of criteria were developed to evaluate the level of formation of scientific and methodological competency as a result of implementing the project for the development of scientific and methodological work. The scientific and methodological work by applying information technology in the academy was carried out in accordance with the following principles: systematic character, consistent diagnostics, practical focus, scientific organizational and methodological support.

• Steel and Composite Structures
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• 제31권6호
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• pp.629-640
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• 2019

The investigation of retaining wall structures behavior under dynamic loads is considered as one of important parts for designing such structures. Generally, the performance of these structures is under the influence of the environment conditions and their geometry. The aim of this research is to design retaining wall structures based on smart and optimal systems. The use of accuracy and speed to assess the structures under different conditions is one of the important parts sought by designers. Therefore, optimal and smart systems are able to have better addressing these problems. Using numerical and coding methods, this research investigates the retaining wall structure design under different dynamic conditions. More than 9500 models were constructed and considered for modelling design. These designs include height and thickness of the wall, soil density, rock density, soil friction angle, and peak ground acceleration (PGA) variables. Accordingly, a neural network system was developed to establish an appropriate relationship between data to obtain safety factor (SF) of retaining walls under different seismic conditions. Different parameters were analyzed and the effect of each parameter was assessed separately. According to these analyses, the structure optimization was performed to increase the SF values. The optimal and smart design showed that under different PGA conditions, the structure performance can be appropriately improved while utilization of the initial (or basic) parameters leads to the structure failure. Therefore, by increasing accuracy and speed, smart methods could improve the retaining structure performance in controlling the wall failure. The intelligent design process of this study can be applied to some other civil engineering applications such as slope stability.

• 한국정보통신학회논문지
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• 제22권11호
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• pp.1505-1510
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• 2018

그래픽스 분야의 제품모델링 제작기술은 급속하게 발전하고 있고 3차원 데이터 응용과 활용성은 계속 증가하고 있다. 제품디자인 제작에 있어 3차원 모델링 제작에는 많은 시간이 소요된다. 최근 역설계 방식은 3D 데이터의 응용과 제작시간단축으로 활용성이 크다. 본 연구는 영상데이터 기반으로 포토메트리를 이용하여 3차원 포인트 클라우드 및 메쉬 데이터를 추출하고 이를 응용하여 제품의 1차 시안을 제작한다. 디자인 수정에 중점을 두어 2차 시안이 제작되었으며 3차 시제품 제작을 위한 3D 프린팅 작업을 진행한다. 이러한 제품디자인 제작과정에서 영상데이터의 활용과 가능성 및 3D 모델링 제작시간의 단축, 효율적인 프로세스를 제시한다. 또한 제품디자인 환경변화에 대응하기 위한 신제품 개발 프로세스 시스템의 모델을 제안한다.

• Coupled systems mechanics
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• 제8권2호
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• pp.169-184
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• 2019

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

• 전기전자학회논문지
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• 제23권3호
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• pp.1108-1111
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• 2019

본 논문은 LLC 공진 컨버터에 적합한 자동화 권선 변압기 설계에 대한 포괄적인 방법에 대해서 나타낸다. 기존의 LLC 공진 변압기는 하나의 보빈에 모든 권선이 감겨져 있기 때문에 자동화 권선 구현이 어렵다는 문제점이 있다. 따라서 본 논문에서는 절연 테이프와 배리어 테이프가 없이 다중 보빈으로 자동 권선이 가능한 LLC 공진 변압기를 제안하였으며 제안한 LLC 공진 변압기의 설계 절차에 대해서도 나타내었다. Maxwell 3D 시뮬레이션 툴을 이용하여 제안한 LLC 공진 변압기의 해석 및 모델링을 상세하게 기술되었으며 또한 3D 모델링에 의해 제작된 제안한 LLC 공진 변압기를 이용하여 프로타입 150W LLC 공진 컨버터를 실험을 통해 확인하였다.

• Computers and Concrete
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• 제24권2호
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• pp.125-135
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• 2019

Concrete pipelines are the most efficient and safe means for gas and oil transportation over a long distance. The use of nano materials and nono-engineering can be considered for enhancing concrete pipelines properties. the tests show that SiO2 nanoparticles can improve the mechanical behavior of concrete. Moreover, severe hazard for pipelines is seismic ground motion. Over the years, scientists have attempted to understand pipe behavior against earthquake most frequently via numerical modeling and simulation. Therefore, in this paper, the dynamic response of underwater nanocomposite submerged pipeline conveying fluid is studied. The structure is subjected to the dynamic loads caused by earthquake and the governing equations of the system are derived using mathematical model via Classic shell theory and Hamilton's principle. Navier-Stokes equation is employed to calculate the force due to the fluid in the pipe. As well, the effect of external fluid is modeled with an external force. Mori-Tanaka approach is used to estimate the equivalent material properties of the nanocomposite. 1978 Tabas earthquake in Iran is considered for modelling seismic load. The dynamic displacement of the structure is extracted using differential quadrature method (DQM) and Newmark method. The effects of different parameters such as SiO2 nanoparticles volume percent, boundary conditions, thickness to radius ratios, length to radius ratios, internal and external fluid pressure and earthquake intensity are discussed on the seismic response of the structure. From results obtained in this paper, it can be found that the dynamic response of the pipe is increased in the presence of internal and external fluid. Furthermore, the use of SiO2 nanoparticles in concrete pipeline reduces the displacement of the structure during an earthquake.

• Computers and Concrete
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• 제23권1호
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• pp.61-68
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• 2019

This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.1-14
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• 2021

The study has been carried out with an objective to prepare Siberian roe deer habitat potential maps in South Korea based on three geographic information system-based models including frequency ratio (FR) as a bivariate statistical approach as well as convolutional neural network (CNN) and long short-term memory (LSTM) as machine learning algorithms. According to field observations, 741 locations were reported as roe deer's habitat preferences. The dataset were divided with a proportion of 70:30 for constructing models and validation purposes. Through FR model, a total of 10 influential factors were opted for the modelling process, namely altitude, valley depth, slope height, topographic position index (TPI), topographic wetness index (TWI), normalized difference water index, drainage density, road density, radar intensity, and morphological feature. The results of variable importance analysis determined that TPI, TWI, altitude and valley depth have higher impact on predicting. Furthermore, the area under the receiver operating characteristic (ROC) curve was applied to assess the prediction accuracies of three models. The results showed that all the models almost have similar performances, but LSTM model had relatively higher prediction ability in comparison to FR and CNN models with the accuracy of 76% and 73% during the training and validation process. The obtained map of LSTM model was categorized into five classes of potentiality including very low, low, moderate, high and very high with proportions of 19.70%, 19.81%, 19.31%, 19.86%, and 21.31%, respectively. The resultant potential maps may be valuable to monitor and preserve the Siberian roe deer habitats.

• 환경영향평가
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• 제31권5호
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• pp.271-285
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• 2022

본 연구에서는 AERMOD 기상 전처리 프로그램인 AERMET에 대표적 지표기상 형식인 CD-144와 ISHD를 적용하여 처리 결과를 비교하고, 환경부 토지피복도를 고려하여 대기확산 정도를 분석하였다. 연구결과, knot 단위를 사용하는 CD-144 형식의 경우 단위 변환 오차로 인해 실제 풍속을 고려하지 못하였으나 ISHD 형식은 그대로 반영하는 것으로 나타났다. 점오염원 1시간 최대 농도값은 ISHD가 CD-144에 비해 높았으며, 그 외에는 동일하거나 낮아지는 것으로 나타났다. 환경부 토지피복도를 반영한 농도값은 토지피복도를 고려하지 않은 경우보다 최대 387% 증가하였으며, 등농도곡선 형태(곡선의 방향 및 길이)에도 차이가 있는 것으로 나타났다. 환경영향평가 및 통합환경허가에서의 모델 사용은 동일한 조건에서의 통일된 판단을 요구하므로 AERMET 사용시 ISHD 형식의 사용과 함께 모델링 지역의 토지피복을 고려할 필요가 있다.

• Steel and Composite Structures
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• 제44권1호
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• pp.33-47
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• 2022

This paper presents a finite element model for predicting the monotonic behaviour of bolted endplate joints connecting steel-concrete composite walls and steel beams. The demountable Hollo-bolts are utilised to facilitate the quick installation and dismantling for replacement and reuse. In the developed model, material and geometric nonlinearities were included. The accuracy of the developed model was assessed by comparing the numerical results with previous experimental tests on hollow/composite column-to-steel beam joints that incorporated endplates and Hollo-bolts. In particular, the Hollo-bolts were modelled with the expanded sleeves involved, and different material properties of the Hollo-bolt shank and sleeves were considered based on the information provided by the manufacture. The developed models, therefore, can be applied in the present study to simulate the wall-to-beam joints with similar structural components and characteristics. Based on the validated model, the authors herein compared the behaviour of wall-to-beam joints of two commonly utilised composite walling systems (Case 1: flat steel plates with headed studs; Case 2: lipped channel section with partition plates). Considering the ease of manufacturing, onsite erection and the pertinent costs, composite walling system with flat steel plates and conventional headed studs (Case 1) was the focus of present study. Specifically, additional headed studs were pre-welded inside the front wall plates to enhance the joint performance. On this basis, a series of parametric studies were conducted to assess the influences of five design parameters on the behaviour of bolted endplate wall-to-beam joints. The initial stiffness, plastic moment capacity, as well as the rotational capacity of the composite wall-to-beam joints based on the numerical analysis were further compared with the current design provision.