• Journal for History of Mathematics
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• v.15 no.1
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• pp.115-134
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• 2002

The increasing use of computers in mathematics and in mathematics education is strongly reflected in the teaching on Euclid geometry, in particular in the use of dynamic graphics software. This development has raised questions about the role of analytic proof in school geometry. One can sometimes find a proof which is rather more explanatory than the one commonly used. Because we, math educators are concerned with tile explanatory power of the proofs, as opposed to mere verification, we should devise ways to use dynamic software in the use of explanatory proofs.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.353-356
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• 2023

본 논문에서는 GPU 기반으로 옷감을 찢는 데 필요한 동적 재메쉬 기법에 대해서 제안한다. 일반적으로 메쉬를 파괴(Fracture)하거나 찢는 시뮬레이션에서는 안정적인 동역학 계산하는데 있어서 동적 재 메쉬과정에 매우 중요하며 이 과정이 계산양이 가장 크다. 본 논문에서는 GPU 친화적인 동적 메쉬 알고리즘을 새롭게 제안함으로써 옷감 찢기 시뮬레이션을 실시간으로 보여준다.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.213-222
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• 2014

In this paper, we introduce that MAAB style guideline has effects on the codes generated from Simulink models for static and dynamic software testing, when weapon system embedded software design and implementation are performed using the model based method. As showing the effects, MAAB guideline is helpful for defect prevention related with coding rules and run time errors associated with the DAPA weapon system embedded software guide. Thus, we check related items between MAAB and DAPA software reliability testing including static and dynamic analysis. And then we propose the criterion to select proper items from MAAB for DAPA guideline and show how to verify the relationship and the effects on reliability of models in Simulink. In addition, we show the needs for clear logics in conditional block models or statements and simple complexity models for Simulink model based design.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.257-262
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• 2015

As software grows more complex, it contains more bugs that are not recognized by developers. Attackers can then use exploitable bugs to penetrate systems or spread malicious code. As a representative method, attackers manipulated documents or multimedia files in order to make the software engage in unanticipated behavior. Recently, this method has gained frequent use in A.P.T. In this paper, an automatic analysis method to find software security bugs was proposed. This approach aimed at finding security bugs in the software which can arise from input data such as documents or multimedia. Through dynamic taint analysis, how input data propagation to vulnerable code occurred was tracked, and relevant instructions in relation to input data were found. Next, the relevant instructions were translated to a formula and vulnerable input data were found via the formula using an SMT solver. Using this approach, 6 vulnerable codes were found, and data were input to crash applications such as HWP and Gomplayer.

• Journal of Advanced Technology Convergence
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• v.2 no.3
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• pp.59-66
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• 2023

The most important thing in digital transformation is SW technology. However, many companies are having difficulty securing SW technology and manpower. In particular, it is reported that the shortage of SW manpower will increase further. The government is carrying out manpower training policies and many support projects to resolve SW manpower supply and demand policies, but accurate predictions of demand and supply of the software industry are essential for these policies to be effectively established. Therefore, this study developed a simulation using a system dynamics methodology that can perform dynamic structural analysis to resolve the supply and demand imbalance in the software industry. System dynamics is appropriate to find the cause and policy alternatives from a dynamic perspective on the imbalance in manpower supply and demand in the software industry. In detail, the U.S. Bureau of Labor Statistics (BLS) methodology was used to develop a prediction model for manpower demand and supply in the software industry, and scenario analysis was performed to derive policy implications.

• Journal of Internet Computing and Services
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• v.16 no.6
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• pp.47-55
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• 2015

The conventional dynamic routing methods in Software Defined Networks (SDN) set the optimal routing path based on the minimum link cost, and thereby transmits the incoming or outgoing flows to the terminal. However, in this case, flows can bypass the middlebox that is responsible for security service and thus, thus the network can face a threat. That is, while determining the best route for each flow, it is necessary to consider a dynamic service chaining, which routes a flow via a security middlebox. Therefore, int this paper, we propose a new dynamic routing method that considers the dynamic flow routing method combined with the security service functions over the SDN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1479-1501
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• 2020

Dependable functioning of dynamic networks is essential for delivering ubiquitous services. Faults are the root causes of network outages. The comparison diagnosis model, which automates fault's identification, is one of the leading approaches to attain network dependability. Most of the existing research has focused on stationary networks. Nonetheless, the time-free comparison model imposes no time constraints on the system under considerations, and it suits most of the diagnosis requirements of dynamic networks. This paper presents a novel protocol that diagnoses faulty nodes in diagnosable dynamic networks. The proposed protocol comprises two stages, a testing stage, which uses the time-free comparison model to diagnose faulty neighbour nodes, and a disseminating stage, which leverages a Random Linear Network Coding (RLNC) technique to disseminate the partial view of nodes. We analysed and evaluated the performance of the proposed protocol under various scenarios, considering two metrics: communication overhead and diagnosis time. The simulation results revealed that the proposed protocol diagnoses different types of faults in dynamic networks. Compared with most related protocols, our proposed protocol has very low communication overhead and diagnosis time. These results demonstrated that the proposed protocol is energy-efficient, scalable, and robust.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.1
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• pp.9-16
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• 2009

The analysis of an aircraft flight dynamics is recently very convenient because of the introduction of state-space method and a well-developed package software. The representation of a dynamic system is described as a simple form of matrix calculation and the unique form of model is available for the linear or nonlinear, time variant or time invariant, mono variable or multi variable system with state-space method. And this analysis can be simplified with the specific functions of a package software and it is very simplified to execute the simulation of the dynamic characteristics for an aircraft model with an interactive graphical treatment. The purpose of this study is to develope an educational flight simulator for the students who need to analyze the dynamic characteristics of an aircraft that is primarily to execute the simulation for the analysis of the transient response and frequency response of an aircraft stability. Furthermore the dynamic characteristics of an aircraft motion is set up as dynamical animation tool for the control response on 3-axis motions of an aircraft.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.168-173
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• 2002

The durability test, along with the crashworthiness test, requires the most time and expense in the vehicle development process. The durability design using CAE tools reduces the time required for both the durability test and actual vehicle production. Existing dynamic stress analyses designed fir the analysis of vehicle fatigue mainly calculate the dynamic stress history and fatigue after performing dynamic analysis and stress analysis with relevant software applications and then superpositioning the dynamic load history and stress influence coefficient at each joint. This approach is a complex process, taking into account the flexibility of the parts. It is, however, incapable of giving accurate consideration to the contacts between components, the non-linearity of materials, and tire-road surface interactions. This approach also requires that the analysts have an expertise in software applications of various kinds or an expert in each area must perform the analysis. This requires as a great deal of manpower and time. In order to complement the existing approaches for dynamic stress analysis, this study aims at the following: (1) to suggest the simple and accurate analysis technique which is capable of producing all the possible necessary results; (2) to reduce dramatically the time and manpower needed to construct a model designed to analyze dynamics, quasi-static stress, and fatigue; and (3) to enable an accurate analysis of fatigue by improving the accuracy of dynamic stress. we verify the presented analysis method through durability evaluation of the knuckle of passenger car.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1462-1471
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• 2019

Real-time embedded systems have become pervasive in general industry. They also began to be applied in such domains as avionics, automotive, aerospace, healthcare, and industrial Internet. However, the system failure of such domains could result in catastrophic consequences. Runtime software testing is required in such domains that demands very high accuracy. Traditional runtime software testing based on handwork is very inefficient and time consuming. Hence, test automation methodologies in runtime is demanding. In this paper, we introduce a software testing system that translates a real-time software into a monitorable real-time software. The monitorable real-time software means the software provides the monitoring information in runtime. The monitoring target are time constraints of the input real-time software. We anticipate that our system lessens the burden of runtime software testing.