• Earthquakes and Structures
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• 제12권4호
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• pp.449-455
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• 2017

Using X-braced frames in steel structures is a current procedure to achieve good strength against lateral loads. Study on mid-connections of X-braces and their effects on frame behavior is a subject whose importance has been more or less disregarded by researchers. Experimentally inspecting models involves considerable expense and time; however, computer models can be more suitable substitutes. In this research, a numerical model of X-braced frame has been analyzed using finite element software. The results of pushover analysis of this frame are compared with those of the experimental test. With the help of computer model, the effects of different mid-connection details on ductility and lateral strength of the frame are inspected. Also performances of bolted and welded connections are compared. Taking into account ductility and strength, this study suggests details of a decent pattern for the mid-connection.

• International Journal of Computer Science & Network Security
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• 제21권4호
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• pp.131-139
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• 2021

In current time, anomaly detection is the primary concern of the administrative authorities. Suspicious activity identification is shifting from a human operator to a machine-assisted monitoring in order to assist the human operator and react to an unexpected incident quickly. These automatic surveillance systems face many challenges due to the intrinsic complex characteristics of video sequences and foreground human motion patterns. In this paper, we propose a novel approach to detect anomalous human activity using a hybrid approach of statistical model and Genetic Programming. The feature-set of local motion patterns is generated by a statistical model from the video data in an unsupervised way. This features set is inserted to an enhanced Genetic Programming based classifier to classify normal and abnormal patterns. The experiments are performed using publicly available benchmark datasets under different real-life scenarios. Results show that the proposed methodology is capable to detect and locate the anomalous activity in the real time. The accuracy of the proposed scheme exceeds those of the existing state of the art in term of anomalous activity detection.

• Structural Engineering and Mechanics
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• 제90권1호
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• pp.71-81
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• 2024

Fiber Reinforced Polymer (FRP) bars have now been widely adopted as an alternative to traditional steel reinforcements in infrastructure and civil industries worldwide due variety of merits. This paper presents a numerical methodology to investigate FRP bar-reinforced beam-column joint behavior under quasi-static loading. The proposed numerical model is validated with test results considering load-deflection behavior, damage pattern at beam-column joint, and strain variation in reinforcements, wherein the results are in agreement. The numerical model is subsequently employed for parametric investigation to enhance the end-span beam-column joint performance using different joint reinforcement systems. To reduce the manufacturing issue of bend in the FRP bar, the headed FRP bar is employed in a beam-column joint, and performance was investigated at different column axial loads. Headed bar-reinforced beam-column joints show better performance as compared to beam-column joints having an L-bar in terms of concrete damage, load-carrying capacity, and joint shear strength. The applicability and efficiency of FRP bars at different story heights have also been investigated with varying column axial loads.

• 정보보호학회논문지
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• 제25권3호
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• pp.627-637
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• 2015

온라인 게임시장의 성장으로 아이템 거래시장이 활성화됨에 따라 아이템 현금 거래시장은 1조 6,000억원 규모로 성장하였으며, 활성화된 시장으로 인해 아이템 및 게임머니의 현금화가 용이하게 되었다. 이러한 특성으로 악의적인 사용자들은 온라인 게임에서 계정도용을 통해 금전적인 가치가 높은 희귀 아이템 및 게임머니를 탈취하여 현금화하는 사례가 빈번히 발생하고 있는 실정이다. 본 연구에서는 MMORPG(Massive Multi-user Online Role Playing Game)내에서의 계정도용자들의 행위분석을 통한 계정도용 탐지모델을 제안한다. 계정도용의 경우 현금화 시킬 수 있는 아이템 및 게임머니를 탈취해야하기 때문에 게임 행동상에서 경제활동에 치중되어 있으며 아이템 생산, 아이템 판매, 게임머니 획득 이라는 특정 시퀀스를 가지고 있다. 이를 기반으로 계정도용 탐지모델을 제안하였으며, 본 논문의 탐지모델을 활용하여 분류한 결과 84%의 정확도를 보였다. 더불어 거래 네트워크 분석을 통해 계정도용 시 발생하는 거래특성에 대해 분석하였다.

• 한국지반공학회논문집
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• 제18권5호
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• pp.123-132
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• 2002

본 연구에서는 인간의 사고과정을 근거로 개발된 동적 인공신경망을 이용하여 이암풍화토의 전단거동을 예측하였다. 흙의 비선형거동을 예측함에 있어 피드백 과정에 의해 시간경과에 따른 패턴의 특성변화를 연속적으로 예측할 수 있는 동적신경망의 종류인 SNN모델과 RNN모델을 이용하였다. 인공신경망의 학습능력과 예측능력에 영향을 미치는 여러 변수등을 분석후 SNN모델에서는 학습율, 모멘텀 상수, 신경망구조가 0.5, 0.7, 8$\times$18$\times$2, RNN모델인 경우는 각각 0.3,0.9,8$\times$24$\times$2의 구조가 적합한 것으로 나타났다 예측결과는 두 네트워크 모두 정규압밀 상태의 전단거동을 잘 예측하였지만, 과압밀 상태의 전단거동 예측에서는 불규칙적인 입력패턴에 효과적인 RNN모델의 예측능력이 더욱 우수하였다.

• 국제초고층학회논문집
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• 제2권1호
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• pp.79-83
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• 2013

Shaking table test is an important and useful method to help structural engineers get better knowledge about the seismic performance of the buildings with complex structure, just like Shanghai tower. According to Chinese seismic design guidelines, buildings with a very complex and special structural system, or whose height is far beyond the limitation of interrelated codes, should be firstly studied through the experiment on seismic behavior. To investigate the structural response, the weak storey and crack pattern under earthquakes of different levels, and to help the designers improve the design scheme, the shaking table model tests of a scaled model of Shanghai tower were carried out at the State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China. This paper describes briefly the structural system, the design method and manufacture process of the scaled model, and the test results as well.

• 한국게임학회 논문지
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• 제11권1호
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• pp.121-129
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• 2011

온라인 게임에서 오토 프로그램 또는 봇 프로그램으로 인하여 다양한 게임 서비스 피해사례가 발생하고 있다. 특히, 게임 머니 및 아이템의 비정상적인 수집은 게임이 가지는 본연의 재미를 잃어버리게 되고, 궁극적으로 게임 생명주기에 결정적 악영향을 미치게 된다. 본 논문은 게임 봇 감지를 위해 게임 행위 변화 패턴을 수집하고 분석하여 봇 탐지 방법에 적용한다. 인간의 게임 행위 변화 정보와 봇의 게임 행위 변화 정보를 이용하여 유사정도를 측정하고, 봇 탐지 기법에 활용하는 것이다. 실험에서는 서비스 중인 온라인 게임을 이용하여 사용자와 봇의 모델을 생성하고 유사성을 판별하였으며 적절한 결과를 확인하였다.

• 대한가정학회지
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• 제41권8호
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• pp.139-158
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• 2003

This study investigated the effects of Korean parents' family-of-origin experiences, marital conflict, open or dysfunctional communication with their children, children's coping behaviors on their behavior problems as a function of a child's sex. Theoretical models for both sexes were constructed based on the results. Two hundred and nine boys and one hundred and ninety six girls of 4th and 5th grades from two elementary schools filled out the questionnaires to assess their communication with the parents, their problem-focused coping behaviors, and their internalizing and externalizing behavior problems. Four hundred five parents of these children answered the questionnaires to assess differentiation for the family-of-origin and the marital conflict. The results were as follows. Boys' path pattern showed that the fathers' differentiation from the family-of-origin effected their sons' internalizing and externalizing behavior problems through parent-child dysfunctional communication. Girls' path exhibited two different patterns. One is that the mothers' differentiation from the family-of-origin effected their daughters' internalizing and externalizing behavior problems through parent-child dysfunctional communication. Another one is that the mothers' differentiation from the family-of-origin influenced children's internalizing behavior problems through daughters' problem-focused coping behaviors as well as parent-child dysfunctional communication.

• 기술혁신연구
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• 제14권2호
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• pp.29-48
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• 2006

This paper analyzes organizational behavior of an established firm when disruptive innovation, a change in product architecture, occurs on a previous product. For the analysis, the paper analyzes and compares the behavior of an established fm through product trajectories between NEC (an established firm) and Toshiba (a new entrance) in the Japanese laptop computers industry. An established firm that has developed and produced a previous product is difficult in adapting to a disruptive innovation due to accumulated immense knowledge through a previous product. By using regression model in the product trajectory analysis, the paper analyzes the behavior of established firms. Product trajectory means a pattern of product strategy shown in a series of products. Two facts found in the paper are as follows. First, though NEC was able to develop a laptop computer at the same time with Toshiba, it was restricted by the resources of a previous product in the early stage. Second, possibility of teaming trap in the adapting process was found. The paper found the risk that too much commitment in one evolution stage would prohibit the adapting behavior in the next evolution stage.

• Computers and Concrete
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• 제19권4호
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• pp.365-374
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• 2017

With the continuous evolution of the numerical methods and the availability of advanced constitutive models, it became a common practice to use complex physical and geometrical nonlinear numerical analyses to estimate the structural behavior of reinforced concrete elements. Such simulations may yield the complete time history of the structural behavior, from the first moment the load is applied until the total collapse of the structure. However, the evolution of the cracking pattern in geometrical discontinuous zones of reinforced concrete elements and the associated failure modes are relatively complex phenomena and their numerical simulation is considerably challenging. The objective of the present paper is to assess the applicability of the Applied Element Method in simulating the development of distinct failure modes in reinforced concrete walls subjected to monotonic loading obtained in experimental tests. A pushover test was simulated numerically on three distinct RC shear walls, all presenting an opening that guarantee a geometrical discontinuity zone and, consequently, a relatively complex cracking pattern. The presence of different reinforcement solutions in each wall enables the assessment of the reliability of the computational model for distinct failure modes. Comparison with available experimental tests allows concluding on the advantages and the limitations of the Applied Element Method when used to estimate the behavior of reinforced concrete elements subjected to monotonic loading.