• Restorative Dentistry and Endodontics
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• v.42 no.2
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• pp.134-139
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• 2017

Objectives: To compare the fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments under static model via artificial canals with different angles of curvature. Materials and Methods: Reciproc R25, WaveOne GOLD Primary, and Tango-Endo instruments were included in this study (n = 20). All the instruments were rotated in artificial canals which were made of stainless steel with an inner diameter of 1.5 mm, $45^{\circ}$, $60^{\circ}$, and $90^{\circ}$ angles of curvatures and a radius of curvature of 5 mm until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The data were analyzed using Kruskal-Wallis and post-hoc Dunn tests were used for the statistical analysis of data in SPSS 21.0 software. Results: Tango-Endo files were found to have significantly higher values than WaveOne GOLD and Reciproc files in terms of fatigue life (p < 0.05). However, there was no statistically significant difference between fatigue life of Reciproc and WaveOne GOLD files (p > 0.05). It was determined that increasing the angle of curvature of the stainless canals caused significant decreases in fatigue life of all of three files (p < 0.05). Conclusions: Within the limitations of the present study, the cyclic fatigue life of Tango-Endo in canals having different angles of curvature was statistically higher than Reciproc and WaveOne GOLD.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2805-2826
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• 2021

In most cases, the routing policy of networks shows a preference for a static one-to-one mapping of communication pairs to routing paths, which offers adversaries a great advantage to conduct thorough reconnaissance and organize an effective attack in a stress-free manner. With the evolution of network intelligence, some flexible and adaptive routing policies have already proposed to intensify the network defender to turn the situation. Routing mutation is an effective strategy that can invalidate the unvarying nature of routing information that attackers have collected from exploiting the static configuration of the network. However, three constraints execute press on routing mutation deployment in practical: insufficient route mutation space, expensive control costs, and incompatibility. To enhance the availability of route mutation, we propose an OpenFlow-based route mutation technique called Polymorphic Path Transferring (PPT), which adopts a physical and virtual path segment mixed construction technique to enlarge the routing path space for elevating the security of communication. Based on the Markov Decision Process, with considering flows distribution in the network, the PPT adopts an evolution routing path scheduling algorithm with a segment path update strategy, which relieves the press on the overhead of control and incompatibility. Our analysis demonstrates that PPT can secure data delivery in the worst network environment while countering sophisticated attacks in an evasion-free manner (e.g., advanced persistent threat). Case study and experiment results show its effectiveness in proactively defending against targeted attacks and its advantage compared with previous route mutation methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.523-528
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• 2015

A new algorithm for a coordinative control method is proposed with respect to voltage control and system stabilization of local substations. This is accomplished using control cooperation between a static synchronous compensator (STATCOM) and the existing voltage compensation equipment in the steady state and emergency state of a power system. A real-time system analysis was developed by combining a system analysis program with InTouch, which has primarily been used in factory automation for verification. PSS/E was used for the load flow calculation software, Python for language, Intouch as an HMI program, and MS SQL for the database. To test this system, the system in the vicinity of the Migeum and the Migeum substations was modeled and simulated.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.124-132
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• 2000

Distributed processing approach for structural optimization is presented in this study. It is implemented on network of personal computers. The validity and efficiency of this approach are demonstrated and verified by test model of truss. Repeated structural analysis algorithm, which spend a lot of overall structural optimization processes, are based on substructuring scheme with domain-wise parallelism and converted to be adapted to hardware and software environments. The design information data are modularized and assigned to each computer in order to minize the communication cost. The communications between nodes are limited to static condensation and constraint-related data collection.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.375-386
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• 2008

Conventional static reliability analysis methods are inadequate for modeling dynamic interactions between components of a system. Various techniques such as dynamic fault tree, dynamic Bayesian networks, and dynamic reliability block diagrams have been proposed for modeling dynamic systems based on improvement of the conventional modeling methods. In this paper, we review these methods briefly and introduce dynamic nodes to the existing reliability graph with general gates (RGGG) as an intuitive modeling method to model dynamic systems. For a quantitative analysis, we use a discrete-time method to convert an RGGG to an equivalent Bayesian network and develop a software tool for generation of probability tables.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.208-212
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• 2003

Silicon transient voltage suppressors (TVSs) are clamping devices that limit voltage spikes by low impedance avalanche breakdown of a rugged silicon PN junction. They are used to protect sensitive components from electrical overstress such as that caused by induces lightning, inductive load switching and electrostatic discharge. In this paper, we present static and dynamic characteristics of TVS diode using thermal analysis simulation software. And also, it is presented that the thermal dissipation characteristics of TVS diode in the transient state.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.759-762
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• 2005

A tray inserting machine is developed for automation of inserting plastic mold tray into a cardboard box. Plastic mold tray is used for protecting breakdown of glass bottles. In this paper, two types of processes to divide the plastic mold tray are proposed. As a result, adhesion method by vacuum pad is accepted. And also, static and modal analysis for the machine are carried out to check the machine design using the commercial software, CATIA V5.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.1
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• pp.9-22
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• 2022

A fighter performing a reconnaissance mission is equipped with a pod that drives optical/infrared sensors for acquiring and identifying target information on the lower part of the fuselage. Due to the nature of the reconnaissance mission, the fighter performs high speed evasive maneuvers, and the resulting load should be considered importantly for the development of the pod. This paper concerns a numerical investigation into the inertial and aerodynamic loads of the airborne pod of high performance aircrafts. For the aerodynamic load analysis, the pylon and pod shapes are added to the fighter 3D model, and the commercial software was used for static and dynamic analysis. Considering the practical mission conditions, the common/extreme conditions were established respectively in the static and dynamic situations of pods and the driving torque could be tripled under dynamic conditions. In the analysis of inertia load, a 3-DOF model considering roll and turning maneuvers was derived by the Lagrangian method, and then the numerical integration method was applied to the analysis. As a results, it was conformed that the inertia load was generally induced at a low level compared to the aerodynamic load, but depending on the unbalance mass condition of the pod, the inertia load cannot be negligible.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.701-713
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• 2021

Race Condition is a vulnerability in which two or more processes input or manipulate a common resource at the same time, resulting in unintended results. This vulnerability can lead to problems such as denial of service, elevation of privilege. When a vulnerability occurs in software, the relevant information is documented, but often the cause of the vulnerability or the source code is not disclosed. In this case, analysis at the binary level is necessary to detect the vulnerability. This paper aims to detect the Time-Of-Check Time-Of-Use (TOCTOU) Race Condition vulnerability of UNIX kernel-based File System at the binary level. So far, various detection techniques of static/dynamic analysis techniques have been studied for the vulnerability. Existing vulnerability detection tools using static analysis detect through source code analysis, and there are currently few studies conducted at the binary level. In this paper, we propose a method for detecting TOCTOU Race Condition in File System based on Control Flow Graph and Call Graph through Binary Analysis Platform (BAP), a binary static analysis tool.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.2
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• pp.59-67
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• 2009

Computer Aided Engineering(CAE) technology as well as Design(CAD) and Manufacturing(CAM) have been widely adopted in the aerospace industry in order to develop the structure of airplanes, satellites and launch vehicles. Among them, CAE softwares based on finite element methods such as NASTRAN, ABAQUS and ANSYS have gained many engineers' interest in various industries such as automobiles, civils, aircraft and spacecraft. The softwares usually consist of several modules: Static, Dynamic, Vibration, Impact etc. that make analysis specific to meet the design goals of the structure systems. Recent enhancement in the computer hardwares and numerical algorithms enables us to perform complex analysis like multi-physics, optimum design. Also, they make it possible to deal with a large scale problem easily. This paper reviews structural analysis softwares in aerospace industry and gives a summary on its recent development.