• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.96-107
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• 2009

Worm attacks can greatly distort network performance, and countering infections can exact a heavy toll on economic and technical resources. Worm modeling helps us to better understand the spread and propagation of worms through a network, and combining effective types of mitigation techniques helps prevent and mitigate the effects of worm attacks. In this paper, we propose a mathematical model which combines both dynamic quarantine and passive benign worms. This Passive Worm Dynamic Quarantine (PWDQ) model departs from previous models in that infected hosts will be recovered either by passive benign worms or quarantine measure. Computer simulation shows that the performance of our proposed model is significantly better than existing models, in terms of decreasing the number of infectious hosts and reducing the worm propagation speed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.5
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• pp.67-74
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• 2010

Recently, the early detection and prevention of worm research is mainly studying based on the analysis of generalized worm propagation property. However, it is not easy to do Worm early detection with its attributes because the modeling method for Worm propagation is vague and not specified yet. Worm scanning method is exceedingly effect to Worm propagation process. This paper describes a modeling method and its simulations to estimate various worm growth patterns and their corresponding propagation algorithms. It also tests and varies the impact of various improvements, starting from a trivial simulation of worm propagation and the underlying network infrastructure. It attempts to determine the theoretical maximum propagation speed of worms and how it can be achieved. Moreover, we present the feasibility of the proposed model based on real testbed for verification.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.250-256
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• 2015

We present a novel method to model the body posture of a worm for vision-based automatic monitoring and analysis. The worm considered in this study is a Caenorhabditis elegans (C. elegans), which is popularly used for research in biological science and engineering. We model the posture by an open chain of a few curved or rigid line segments, in contrast to previously published approaches wherein a large number of small rigid elements are connected for the modeling. Each link segment is represented by only two parameters: an arc angle and an arc length for a curved segment, or an orientation angle and a link length for a straight line segment. Links in the proposed method can be readily related using the Denavit-Hartenberg convention due to similarities to the kinematics of an articulated manipulator. Our method was tested with real worm images, and accurate results were obtained.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.73-86
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• 2007

Numerous types of models have been developed in recent years in response to the cyber threat posed by worms in order to analyze their propagation and predict their spread. Some of the most important ones involve mathematical modeling techniques such as Epidemic, AAWP (Analytical Active Worm Propagation Modeling) and LAAWP (Local AAWP). However, most models have several inherent limitations. For instance, they target worms that employ random scanning in the entire nv4 network and fail to consider the effects of countermeasures, making it difficult to analyze the extent of damage done by them and the effects of countermeasures in a specific network. This paper extends the equations and parameters of AAWP and LAAWP and suggests ALAAWP (Advanced LAAWP), a new worm simulation technique that rectifies the drawbacks of existing models.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.43-53
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• 2007

Internet becomes more and more popular, and most companies and institutes use web services for e-business and many other purposes. With the explosion of Internet, the occurrence of cyber terrorism has grown very rapidly. Simulation is one of the most widely used method to study internet worms. But, it is quite challenging to simulate very large-scale worm attacks because of various reasons. In this paper, we propose a hybrid modeling method for RCS(Random Constant Spreading) worm simulation. The proposed hybrid model simulates worm attacks by synchronizing modeling network and packet network. So, this model will be both detailed enough to generate realistic packet traffic, and efficient enough to model a worm spreading through the Internet. Moreover, our model have the capability of dynamic updates of the modeling parameters. Finally, we simulate the hybrid model with the CodeRed worm to show validity of our proposed model for RCS worm simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1893-1896
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• 2005

Cutting force and face roughness have the largest influence on precision of a structure or processing efficiency in cutting processing. Thus cutting force model and face roughness model are necessary for this interpretation. In this paper, tool path model and face roughness model which consider the blade number of a tool and a revolution speed of tool and workpiece in the worm processing using side milling cutter are presented. This model was used to forcast the cusp. Experimental results show that the predicted cusp coincides with experimental one.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.212-218
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• 2012

An Internet worm is a self-replicating malware program which uses a computer network. As the network connectivity among computers increases, Internet worms have become widespread and are still big threats. There are many approaches to model the propagation of Internet worms such as Code Red, Nimda, and Slammer to get the insight of their behaviors and to devise possible defense methods to suppress worms' propagation activities. The influence of the network characteristics on the worm propagation has usually been modeled by medical epidemic model, named SI model, due to its simplicity and the similarity of propagation patterns. So far, SI model is still dominant and new variations of the SI model, called SI-style models, are being proposed for the modeling of new Internet worms. In this paper, we elaborate the problems of SI-style models and then propose a new accurate stochastic model using an occupancy problem.

• Transactions of Materials Processing
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• v.28 no.4
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• pp.183-189
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• 2019

Cylindrical worm reducers are generally used in various fields and forms throughout the industry, and demand is increasing due to their role as an integral part of the industry. Market trends require high-load, high-precision components, and small-sized reducers with large loads. When using a cylindrical worm reducer, a reducer designed with a reduced center distance while maintaining the same output torque results in gear wear. To overcome this difficulty, an enveloping worm gear reducer is introduced and studied. In this paper, three types of end mill tools are used to evaluate the tooth profile accuracy for each tool shape during machining of the tooth profile for a non-developed surface worm thread. The effect of the endmill shape on the accuracy of the tooth profile was analyzed by performing 3D modeling of the surrounding worm tooth profile based on the Hindley method. In this study, we analyzed tooth profile accuracy, tooth surface roughness, and tooth surface machining time, etc. Through the study, efficient machining conditions for the enveloping worm gears and the influence of parameters on the process were presented.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.171-179
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• 2005

Computer virus modeling and simulation research has been conducted with focus on the network vulnerability analysis. However, computer virus generally shows the biological virus characters such as proliferation, reproduction and evolution. Therefore it is necessary to research the computer virus modeling and simulation using Artificial Life. The approach of computer modeling and simulation using the Artificial Life technology Provides the efficient analysis method for the effects on the network by computer virus and the behavioral mechanism of the computer virus. Hence this paper proposes the methodology of computer virus modeling and simulation using Artificial Life, which may be contribute the research on the computer virus vaccine.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2858-2864
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• 2015

Internet worms have been the major Internet threats may disclose important information and can bring about faults of computer systems, which spread with the fastest speed among malicious codes. Simultaneously spreading multiple worms and its variants are revealing the limitation of conventional responses based on single worms. In order to defend them effectively, it is necessary to study how multiple worms propagate and what factors affect worm spreading. In this paper, we improve the existed single worm spreading models and try to describe the correct spreads of multiple worms. Thus we analyze the spreading effects of multiple worms and its variants by various experiments.