• Structural Engineering and Mechanics
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• v.83 no.1
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• pp.19-29
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• 2022

The angle steel frame confined concrete columns (ASFCs) are an emerging form of hybrid columns, which comprise an inner angle steel frame and a concrete column. The inner angle steel frame can provide axial bearing capacity and well confining effect for composite columns. This paper presents the experimental and theoretical studies on the seismic behaviour of ASFCs. The experimental study of the 6 test specimens is presented, based on the previous study of the authors. The theoretical study includes two parts. One part establishes the section analysis model, and it uses to analyze section axial force-moment-curvature. Another part establishes the section moment-curvature hysteresis model. The test and analysis results show that the axial compression ratio and the assembling of steel slabs influence the local buckling of the angle steel. The three factors (axial compression ratio, content of angle steel and confining effect) have important effects on the seismic behaviour of ASFCs. And the theoretical model can provide reasonably accurate predictions and apply in section analysis of ASFCs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2101-2123
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• 2023

Recent studies have shown that the neural network-based binary code similarity detection technology performs well in vulnerability mining, plagiarism detection, and malicious code analysis. However, existing cross-architecture methods still suffer from insufficient feature characterization and low discrimination accuracy. To address these issues, this paper proposes a cross-architecture binary function similarity detection method based on composite feature model (SDCFM). Firstly, the binary function is converted into vector representation according to the proposed composite feature model, which is composed of instruction statistical features, control flow graph structural features, and application program interface calling behavioral features. Then, the composite features are embedded by the proposed hierarchical embedding network based on a graph neural network. In which, the block-level features and the function-level features are processed separately and finally fused into the embedding. In addition, to make the trained model more accurate and stable, our method utilizes the embeddings of predecessor nodes to modify the node embedding in the iterative updating process of the graph neural network. To assess the effectiveness of composite feature model, we contrast SDCFM with the state of art method on benchmark datasets. The experimental results show that SDCFM has good performance both on the area under the curve in the binary function similarity detection task and the vulnerable candidate function ranking in vulnerability search task.

• Earthquakes and Structures
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• v.25 no.1
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• pp.57-67
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• 2023

The buckling of longitudinal reinforcements under seismic loading accelerates the degradation of the bearing capacity of reinforced concrete columns. The traditional hysteretic constitutive model of reinforcement, which does not consider buckling, usually overestimates the seismic performance of pier columns. Subsequent researchers have also proposed many models including the buckling effects. However, the accuracy of these hysteretic constitutive models proposed for simulating the buckling behavior is inadequate. In this study, based on their works, the influence of historical events on buckling is considered, the path of the re-tensioning phase is corrected by adjusting the boundary lines, and the positions of the onset buckling point and compressive buckling path during each buckling deformation are corrected by introducing correction parameters and a boundary line. A modified hysteretic constitutive model is obtained, that can more accurately reflect the buckling behavior of reinforcements. Finally, a series of hysteresis tests of reinforcements with different slenderness ratios were then conducted. The experimental results verify the effectiveness of the proposed modified model. Indicating that the modified model can more accurately simulate the equivalent stress-strain relationship of the buckling reinforcement segment.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.631-642
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• 2009

Although the Korean government is making great effort to prevent the redundancy in IT investment and efficiently allocate the IT budget, actual achievements are quite limited because of the variety of IT resources and different architecture description among organizations and projects. Thus, a standardized description model of the system architecture is strongly needed to identify the common resources and improve the efficiency of IT investment. Therefore, in this paper, we have developed the function-network matrix model which can be used as the basic template for a standard for architecture description of e-Government systems. The function-network matrix model integrates the function tiers and the network areas into a single unified framework, which enables the functionality of each component and the flow of information clearly visible. Moreover, we described the architectures of Korean e-government’s citizen service systems using our model, resulting in clear demonstration of the similarities and differences between different systems, and easy identification of the common resources. Using the architecture description model developed in this research, the consolidation of national IT resources can be promoted, and non-expert IT users can easily recognize the architecture of their systems. In addition, more efficient and systematic IT resource management can be achieved using our model.

• The Journal of Information Systems
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• v.20 no.1
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• pp.107-126
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• 2011

Model-based decision support system (DSS) has acted as a crucial role in strengthening the business competitiveness by providing a way of modeling and solving real-world decision problems in a quantitative and scientific manner. It is even more important for trading OTC derivatives, which requires extensive financial-engineering expertise while actively reacting to the continuously changing financial market. This paper proposes a flexible model-based DSS architecture that can support user-friendly interface for executing and analyzing the models and can adapt to the changes of financial market seamlessly. For user-friendliness, we implement the user-interfaces (UIs) using Microsoft Excel, a very widely used spreadsheet program for its great generality and extensibility. Users can utilize the analysis results of DSS or reprocess them for their special needs through the UIs in the form of familiar spreadsheets easily. For adaptiveness to the markets, the proposed architecture is constructed based on the object-oriented concepts, which enables such changes as release of a new financial product can be updated into the system without any delay at the lowest cost. We investigate the practical benefits and limitations of the proposed architecture by a case study on the construction of Model-based Trading Support System (MTSS), performed by a commercial bank in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.122-127
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• 2009

In this paper, it is reviewed security architecture and proposed security model about secure aeronautical system, which is considering in the cynical research topics out of aeronautical traffic system. The reviewed contents is treated about security model fur domestic aeronautical system with international security technology trends in the basis of security technology related aeronautical services. In the security framework of aeronautical communication network, it is analyzed data link security technology between air and ground communication, and security architecture in according to aeronautical system, and presented security architecture of U information HUB model. The security architecture of U-information HUB includes the internetworking scope of airline, airport network, airplane network, and related government agency, etc.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.683-690
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• 2004

MND(Ministry of National Defense) has developed .nm AF(Ministry of National Defense Architecture Framework) to guarantee interoperability among defense information systems. Users can easily and consistently develop architecture products through MND AF. There is necessity for development if CADM(Core Architecture Data Model), which facilitate exchange, integration, and comparison for architecture data, to store architecture data from architecture products and reuse them. We developed CADM from defining entities and relationships that satisfy data requirement of each architecture product from MND AF. After we developed architecture products about MIMS(Military Intelligence Management System), and inserted these architecture data to CADM repository. we verified CADM entities and relationships through query. Through CABM which provides common data model for the whole my architectures, interoperability and integration among defense information systems ran be improved, and integrated defense information resources efficiently can be managed.

• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.481-488
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• 2020

Composite materialsuch as glass-fiber reinforced plastic and carbon-fiber reinforced plastic (CFRP) shows anisotropic property and have been widely used for structural members and outfitings of ships. The structural safety of composite structures has been generally evaluated via finite element analysis. This paper presents a technique for updating the finite element model of anisotropic beams or plates via natural frequencies. The finite element model updates involved a compensation process of anisotropic material properties, such as the elastic and shear moduli of orthotropic structural members. The technique adopted was based on a discrete genetic algorithm, which is an optimization technique. The cost function was adopted to assess the optimization problem, which consisted of the calculated and referenced low-order natural frequencies for the target structure. The optimization process was implemented with MATLAB, which includes the finite element updates and the corresponding natural frequency calculations with MSC/NASTRAN. Material properties of a virtual cantilevered orthotropic beam were estimated to verify the presented method and the results obtained were compared with the reference values. Furthermore, the technique was applied to a cantilevered CFRP beam to successfully estimate the unknown material properties.

• Geomechanics and Engineering
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• v.18 no.3
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• pp.291-298
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• 2019

In order to study the mechanical properties of rock salt, triaxial compression tests under different temperatures and confining pressure are carried out on rock salt specimens, the influence of temperature and confining pressure on the mechanical properties of rock salt was studied. The results show that the temperature has a deteriorative effect on the mechanical properties of rock salt. With the increase of temperature, the peak stress of rock salt decreases visibly; the plastic deformation characteristics become much obvious; the internal friction angle increases; while the cohesion strength decreases. With the increase of confining pressure, the peak stress and peak strain of rock salt will increase under the same temperature. Based on the test data, the Duncan-Chang constitutive model was modified, and the modified Duncan-Chang rock salt constitutive model considering the effect of temperature and confining pressure was established. The stress-strain curve calculated by the modified model was compared with the stress-strain curve obtained from the test. The close match between the test results and the model prediction suggests that the modified Duncan-Chang constitutive model is accurate in describing the behavior of rock slat under different confining pressure and temperature conditions.

• Architectural research
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• v.8 no.2
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• pp.43-48
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• 2006

The appropriate fleet estimation of the excavation equipment is a major factor in the determination of the cost and time requirements of a project. But the decision of what kind of equipment selected is often based on heuristic methods or trial and error in Korea. Thus, this study proposes a prototype model that uses genetic algorithms to select fleet estimation of loaders (backhoe) and trucks used in excavation work. To verify the applicability of this model, the case study was performed. And the result of the genetic model was compared with that of the trial & error method. The use of the genetic model suggested this study required 44days, 2 units of backhoes, 7 units of trucks, and a total cost of 171,839,756 won. With the estimated fleet number of equipment, the minimum cost of excavation work can be calculated, taking account of the time-cost trade-off. By utilizing this prototype model, the efficiency of excavation work can be improved.