• 대한건축학회논문집:구조계
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• 제34권4호
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• pp.3-13
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• 2018

Load bearing capacity of dowel type fasteners loaded perpendicular to the shear plane is determined based on Johansen's yield theory (Johansen, 1949). In case of inclined screws whose axis is no longer perpendicular, the ultimate load of connection increases because of additional axial withdrawal capacity. To calculate load bearing capacity for inclined screws, KBC2016 and Eurocode5 provide design equations using the combination of two effects; axial and bending strength. Although their equations have been validated for a long time, there is still minimal information how to apply them for concrete-CLT joints. Since there are not many test data available, engineers have to make certain assumptions and thus results may look inconsistent in practice. In this paper, authors would like to describe the current approach and assumptions indicated by KBC2016 and Eurocode 5 and how they match the experimental results in terms of shear strength of CLT-concrete connections. To fulfill the objective, several push-out tests were performed on nine different test specimens. Each specimen has different penetration angles and depths. By analyzing load-displacement curves, the maximum shear strength, stiffness, and ductility were obtained. Shear strength values were compared with the current design codes and theoretical equations proposed in this paper. Observations on stiffness and ductility were briefly discussed.

• 정보보호학회논문지
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• 제22권5호
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• pp.1103-1113
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• 2012

개인정보유출 방지 솔루션으로 사용되고 있는 DLP 방식 기술은 데스크톱 컴퓨터 중심의 온라인 작업환경에서는 고객 정보 유출 방지에 효과적이었으나 스마트 폰이 일반화되고 스마트 워크가 도입되면서 스마트폰에 의한 개인정보유출과 APT공격에 취약하다는 점이 문제점으로 지적되고 있다. 본고에서는 DLP 기술이 갖고 있는 기본적인 문제점을 해결하기 위해 DLP기술의 내용 검색 기능을 정보 유출 방지 솔루션 E-DRM과 통합한 새로운 개인정보 보호 기술을 제안한다. 내용 검색기능을 활용하되 E-DRM이 갖고 있는 암호화 모듈과 접근제어 기능을 활용함으로 스마트워크 환경에서도 문서가 내부와 외부의 어느 사용자에게 전달되더라도 개인정보 유출을 효과적으로 막을 수 있을 것으로 기대되고 있다.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.319-332
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• 2021

The wood-concrete composite is an interesting solution in the field of Civil Engineering to create high performance bending elements for bridges, as well as in the building construction for the design of wood concrete floor systems. The authors of this paper has been working for the past few years on the development of the bonding process as applied to wood-concrete composite structures. Contrary to conventional joining connectors, this assembling technique does ensure an almost perfect connection between wood and concrete. This paper presents a careful theoretical investigation into interfacial stresses at the level of the two interfaces in composite wooden beam- reinforced concrete slab strengthened by external bonding of prestressed composite plate under a uniformly distributed load. The model is based on equilibrium and deformations compatibility requirements in all parts of the strengthened composite beam, i.e., the wooden beam, RC slab, the CFRP plate and the adhesive layer. The theoretical predictions are compared with other existing solutions. This research is helpful for the understanding on mechanical behaviour of the interface and design of the CFRP- wooden-concrete hybrid structures.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.717-729
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• 2021

This paper examines the efficacy of the default risk factor in an emerging market context using the Fama-French five-factor model. Our aim is to test whether the Fama-French five-factor model augmented with a default risk factor improves the predictability of returns of portfolios sorted on the firm's characteristics as well as on industry. The default risk factor is constructed by estimating the probability of default using a hybrid version of dynamic panel probit and artificial neural network (ANN) to proxy default risk. This study also provides evidence on the temporal stability of risk premiums obtained using the Fama-MacBeth approach. Using a sample of 3,806 firm-year observations on non-financial listed companies of Pakistan over 2006-2015 we found that the augmented model performed better when tested across size-investment-default sorted portfolios. The investment factor contains some default-related information, but default risk is independently priced and bears a significantly positive risk premium. The risk premiums are also found temporally stable over the full sample and more recent sample period 2010-2015 as evidence by the Fama-MacBeth regressions. The finding suggests that the default risk factor is not a useless factor and due to mispricing, default risk anomaly prevails in the Pakistani equity market.

• 한국IT서비스학회지
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• 제20권1호
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• pp.41-54
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• 2021

The SW-centered battlefield management information system R&D project takes a long period of 5-10 years or more by applying a complex and rigid batch acquisition strategy. In order to solve this problem, it is necessary to institutionalize a rapid and flexible battlefield management information system R&D project management procedure applying agile development methodology, and a government project management organization and contract management method to support it In this study, we analyzed the case of applying the Agile development method centered on Scrum to the US SW-centered weapon system R&D project and the characteristics and problems of the battlefield management information system R&D project in Korea, and suggested improvement measures as follows. First, the battlefield management information system R&D model applies the hybrid development method, and the system requirements analysis and system structure design use the existing waterfall development procedure, and the agile method is applied from the SW requirements analysis to the system integration stage. Second, flexible adjustment of performance, schedule, and cost by organizing an Agile IPT in which military (requirements) - DAPA (project management) - developer - functional specialized organizations (test and evaluation, quality, government research institutes, etc.) participate. Third, improving the Basic Order Agreement so that it can be applied to agile R&D.

• Advances in concrete construction
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• 제11권3호
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• pp.239-253
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• 2021

The behavior of concrete containing waste glass as a replacement of cement or aggregate was studied previously in the most of researches, but the present investigation focuses on the recycling of waste glass powder as a substitute for silica fume in high strength concrete (HSC). This endeavor deals with the efficiency of using waste glass powder, as an alternative for silica fume, in the flexural capacity of HSC beam. Thirteen members with dimensions of 0.3 m width, 0.15 m depth and 0.9 m span length were utilized in this work. A comparison study was performed considering HSC members and hybrid beams fabricated by HSC and conventional normal concrete (CC). In addition to the experiments on the influence of glass powder on flexural behavior, numerical analysis was implemented using nonlinear finite element approach to simulate the structural performance of the beams. Same constitutive relationships were selected to model the behavior of HSC with waste glass powder or silica fume to show the matching between the modeling outputs for beams made with these powders. The results showed that the loading capacity and ductility index of the HSC beams with waste glass powder demonstrated enhancing ultimate load and ductility compared with those of HSC specimens with silica fume. The study deduced that the recycled waste glass powder is a good alternative to the pozzolanic powder of silica fume.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.65-74
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• 2022

In natural language processing, commonly used words such as prepositions are referred to as stop-words; they have no inherent meaning and are therefore ignored in indexing and retrieval tasks. The removal of stop-words from Arabic text has a significant impact in terms of reducing the size of a cor- pus text, which leads to an improvement in the effectiveness and performance of Arabic-language processing systems. This study investigated the effectiveness of applying a stop-word lists elimination with normalization as a preprocessing step. The idea was to merge statistical method with the linguistic method to attain the best efficacy, and comparing the effects of this two-pronged approach in reducing corpus size for Ara- bic natural language processing systems. Three stop-word lists were considered: an Arabic Text Lookup Stop-list, Frequency- based Stop-list using Zipf's law, and Combined Stop-list. An experiment was conducted using a selected file from the Arabic Newswire data set. In the experiment, the size of the cor- pus was compared after removing the words contained in each list. The results showed that the best reduction in size was achieved by using the Combined Stop-list with normalization, with a word count reduction of 452930 and a compression rate of 30%.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.1-12
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• 2022

In order to overcome the power fluctuation issues in photovoltaic (PV) smart grid-connected systems and the inverter nonlinearity model problem, an adaptive backstepping command-filter and a double second order generalized Integrators (DSOGI) controller are designed in order to tune the AC current and the DC-link voltage from the DC side. Firstly, we propose to present the filter mathematical model throughout the PV system, at that juncture the backstepping control law is applied in order to control it, Moreover the command filter is bounded to the controller aiming to exclude the backstepping controller differential increase. Additionally, The adaptive law uses Lyapunov stability criterion. Its task is to estimate the uncertain parameters in the smart grid-connected inverter. A DSOGI is added to stabilize the grid currents and eliminate undesirable harmonics meanwhile feeding maximum power generated from PV to the point of common coupling (PCC). Then, guaranteeing a dynamic effective response even under very unbalanced loads and/or intermittent climate changes. Finally, the simulation results will be established using MATLAB/SIMULINK proving that the presented approach can control surely the smart grid-connected system.

• Advances in Computational Design
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• 제7권2호
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• pp.153-171
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• 2022

The present study aimed to find a way to create forms that can simultaneously meet several architectural requirements by applying generative design methods specifically focused on cellular automata. In other words, it is tried to find various forms of architecture that all have common features. Because of the useful features of cellular automata, we decided to use it to generate various forms, but make a relation between the discrete nature of cellular automata and the continuous nature of architecture, was the major problem of our project. To achieve this goal, three consecutive stages were designed. In the first stage, independent variables including the location of the building, the height of the building, and the building area were considered as the inputs of the model. In the second stage, after locating the building, the building's main shell was designed as a hidden geometry for the cellular automata and then the cellular automata were determined based on this shell. The main result of this research is establishing a logical relationship between the discrete geometry of the cellular automata and the continuous search space such that it creates various optimized forms. Although we specify the site plan of this project at Iran-Tehran, this research can be generalized to various design sites as well as different projects, allowing the architectsto alter the cell dimensions, cell density, etc., based on their opinion and project needs.

• Smart Structures and Systems
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• 제29권3호
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• pp.513-522
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• 2022

Due to the importance of accurate analysis of bearing capacity in civil engineering projects, this paper studies the efficiency of two novel metaheuristic-based models for this objective. To this end, black hole algorithm (BHA) and multi-verse optimizer (MVO) are synthesized with an artificial neural network (ANN) to build the proposed hybrid models. Based on the settlement of a two-layered soil (and a shallow footing) system, the stability values (SV) of 0 and 1 (indicating the stability and failure, respectively) are set as the targets. Each model predicted the SV for 901 stages. The results indicated that the BHA and MVO can increase the accuracy (i.e., the area under the receiving operating characteristic curve) of the ANN from 94.0% to 96.3 and 97.2% in analyzing the SV pattern. Moreover, the prediction accuracy rose from 93.1% to 94.4 and 95.0%. Also, a comparison between the ANN's error decreased by the BHA and MVO (7.92% vs. 18.08% in the training phase and 6.28% vs. 13.62% in the testing phase) showed that the MVO is a more efficient optimizer. Hence, the suggested MVO-ANN can be used as a reliable approach for the practical estimation of bearing capacity.