• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.288-294
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• 2021

There are various ways to be infected with malicious code due to the increase in Internet use, such as the web, affiliate programs, P2P, illegal software, DNS alteration of routers, word processor vulnerabilities, spam mail, and storage media. In addition, malicious codes are produced more easily than before through automatic generation programs due to evasion technology according to the advancement of production technology. In the past, the propagation speed of malicious code was slow, the infection route was limited, and the propagation technology had a simple structure, so there was enough time to study countermeasures. However, current malicious codes have become very intelligent by absorbing technologies such as concealment technology and self-transformation, causing problems such as distributed denial of service attacks (DDoS), spam sending and personal information theft. The existing malware detection technique, which is a signature detection technique, cannot respond when it encounters a malicious code whose attack pattern has been changed or a new type of malicious code. In addition, it is difficult to perform static analysis on malicious code to which code obfuscation, encryption, and packing techniques are applied to make malicious code analysis difficult. Therefore, in this paper, a method to detect malicious code through dynamic analysis and static analysis using Trojan-type Downloader/Dropper malicious code was showed, and suggested to malicious code detection and countermeasures.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.827-831
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• 2002

MediaGIS is a concept of tightly integrated multimedia with spatial information. VideoGIS is an example of MediaGIS focused on the interaction or interaction of video and spatial information. Our suggested GeoVideo, a new concept of VideoGIS has its key feature in interactiveness. In GeoVideo, the geographic tasks such as browsing, searching, querying, spatial analysis can be performed based on video itself. GeoVideo can have the meaning of paradigm shift from artificial, static, abstracted and graphical paradigm to natural, dynamic, real, and image-based paradigm. We discuss about the integration of video and geography and also suggest the GeoVideo system design. Several considerations on expanding the functionalities of GeoVideo are explained for the future works.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.57-62
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• 2020

Concrete pump cars are a type of construction equipment that continuously supplies concrete using hydraulic pressure. When manually casting concrete, there may be a problem in the final quality of the concrete due to differences in the degree of cure between the pre-poured and subsequent concretes. Concrete pump cars are the most efficient machines to supply concrete in the shortest time; however, it is difficult to calculate their margin of safety during operation. In this paper, we verified the structural safety of the concrete pump car using a static/dynamic analysis at various position angles. Next, these results were compared with experimental results; strains using strain gages were compared with the strains measured using FEM software to verify the static analysis. In addition, the maximum displacement during the pumping was measured and it was used for fatigue analysis to evaluate the dynamic structural safety.

• Wind and Structures
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• v.30 no.1
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• pp.29-35
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• 2020

This paper presents a comparative structural analysis of lattice hybrid tower with six legs with conventional tubular steel tower for an onshore wind turbine using finite element method. Usually a lattice hybrid tower will have a conventional industry standard 'L' profile section for the lattice construction with four legs. In this work, the researcher attempted to identify and analyze the strength of six legged lattice hybrid tower designed with a special profile instead of four legged L profile. And to compare the structural benefits of special star profile with the conventional tubular tower. Using Ansys, a commercial FEM software, both static and dynamic structural analyses were performed. A simplified finite element model that represents the wind turbine tower was created using Shell elements. An ultimate load condition was applied to check the stress level of the tower in the static analysis. For the dynamic analysis, the frequency extraction was performed in order to obtain the natural frequencies of the tower.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.945-951
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• 2012

In this study, we analyze the static and dynamic characteristics of a bulk-cement trailer with a simpler structure that carries powders. The commercial software ANSYS is used to prepare a detailed three-dimensional model of the chassis frame and tank body that bear most of the load of a bulk-cement trailer for the finite element analysis. Modal analysis is conducted to examine the dynamic characteristics of the trailer body, and static analysis shows weak links in the structure. Finally, we propose a method to increase the strength of vulnerable areas and to reduce the weight of the trailer by applying the Taguchi method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.642-651
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• 2009

The history of excavator design is not long enough which still causes most of the design considerations to be focused on static analysis or simple functional improvement based on static analysis. However, the real forces experiencing on each component of excavator are highly transient and impulsive. Therefore, the prediction and the evaluation of the movement of the excavator by dynamic load in the early design stage through the dynamic transient analysis of the excavator and ensuring of design technique plays an importance role to reduce development-cost, shorten product-deliver, decrease vehicle-weight and optimize the system design. In this paper, Commercial software DADS and ANSYS help to develop the track model of the crawler type excavator, and to evaluate the performance and the dynamic characteristics of excavator with various simulations. For that reason, the track of crawler type excavator is modelled with DADS Track Vehicle Superelement, and the reaction forces on the track rollers were predicted through the driving simulation. Also, the upper frame and cabin vibration characteristics, at the low RPM idle state, were evaluated with engine rigid body modelling. And flexibility body effects were considered to determine the more accurate joint reaction forces and accelerations under the upper frame swing motion.

• Journal of KIISE:Software and Applications
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• v.36 no.7
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• pp.590-606
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• 2009

We present a static analyzer that detects memory leaks in C programs. It achieves relatively high accuracy at a relatively low cost on SPEC2000 benchmarks and several open-source software packages, demonstrating its practicality and competitive edge against other reported analyzers: for a set of benchmarks totaling 1,777 KLOCs, it found 332 bugs with 47 additional false positives (a 12.4% false-positive ratio), and the average analysis speed was 720 LOC/sec. We separately analyze each procedure's memory behavior into a summary that is used in analyzing its call sites. Each procedural summary is parameterized by the procedure's call context so that it can be instantiated at different call sites. What information to capture in each procedural summary has been carefully tuned so that the summary should not lose any common memory-leak-related behaviors in real-world C program. Because each procedure is summarized by conventional fixpoint iteration over the abstract semantics ('a la abstract interpretation), the analyzer naturally handles arbitrary call cycles from direct or indirect recursive calls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.500-506
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• 2009

This study, is aimed to support the valve design engineer by a CAE simulation on the body of a PFA-lined plug valve, and focuses on static stress analysis, location of the weak point on bending and stiffness of the valve body. To determine whether the valve body can resist being transformed by loads, 1 simulated the stress distribution using CAD/CAE softwares. The 'step' file converted by CAD software after solid modeling is imported to the CAE software. Through simulation procedure, it is shown that the designed-solid-model fur a valve body has stiffness on bending and torsion but has weakness for side bending moment. Also, it is expected that the valve design engineer will understand the basic process of CAE and will be able to apply on his task.

• Advances in Computational Design
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• v.4 no.2
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• pp.141-153
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• 2019

This research is comprised of virtually simulating behavior while experiencing low gravity effects in advance of real world testing in low gravity aboard Zero Gravity Corporation's (Zero-G) research aircraft (727-200F). The experiment simulated a drill rig penetrating a regolith simulant. Regolith is a layer of loose, heterogeneous superficial deposits covering solid rock on surfaces of the Earth' moon, asteroids and Mars. The behavior and propagation of space debris when drilled in low gravity was tested through simulations and visualization in a leading dynamic simulation software as well as discrete element modeling software and in preparation for comparing to real world results from flying the experiment aboard Zero-G. The study of outer space regolith could lead to deeper scientific knowledge of extra-terrestrial surfaces, which could lead us to breakthroughs with respect to space mining or in-situ resource utilization (ISRU). These studies aimed to test and evaluate the drilling process in low to zero gravity environments and to determine static stress analysis on the drill when tested in low gravity environments. These tests and simulations were conducted by a team from Texas A&M University's Department of Construction Science, the United States Air Force Academy's Department of Astronautical Engineering, and Crow Industries

• Steel and Composite Structures
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• v.20 no.5
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• pp.1043-1066
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• 2016

A new analytical solution based on a third order shear deformation theory for the problem of static analysis of cross-ply doubly-curved shells is presented. The boundary-discontinuous generalized double Fourier series method is used to solve highly coupled linear partial differential equations with the mixed type simply supported boundary conditions prescribed on the edges. The complementary boundary constraints are introduced through boundary discontinuities generated by the selected boundary conditions for the derivation of the complementary solution. The numerical accuracy of the solution is compared by studying the comparisons of deflections, stresses and moments of symmetric and anti-symmetric laminated shells with finite element results using commercially available software under uniformly distributed load. Results are in good agreement with finite element counterparts. Additional results of the symmetric and anti-symmetric laminated and sandwich shells under single point load at the center and pressure load, are presented to provide data for the unsolved boundary conditions, benchmark comparisons and verifications.