• Journal of the Society of Naval Architects of Korea
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• v.40 no.2
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• pp.41-48
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• 2003

The human behavior is very important in development of simulation system for evacuation analysis. The walking speed of passenger is especially affected by dynamic effect and list due to damage and ship motion in wave. There are various methods to get an useful data for evacuation simulation. The onboard experimental approach is one of the most strong method. In this paper, the onboard experiment is performed to obtain human behavioral data. To realize ship trim and heel due to maritime casuality, the passage model for experiment is made. The experiment is carried out at dynamic and static condition respectively using the ship with passage model. The result is evaluated and it will be reflected in evacuation simulation tool.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.101-109
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• 1997

A tool for the dynamic simulation and design technique of the excavator plays an important role in the prediction of dynamic behavior of the excavator in the initial design stage. In this paper, a flexible multibody dynamic analysis model including track of the crawler type excavator is developed using DADS and ANSYS. Through the driving simulation of the excavator travelling over rough road track, frequency characteristics of the upper frame and cabin are obtained, and the reaction forces acting on the track rollers are also presented for the fatigue life estimation. The effect of boom vibration modes on the joint reaction forces and accelerations is presented from the swing simulation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.1
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• pp.39-53
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• 1994

To investigate the behaviour of the embankment on very soft foundation reinforced geotex- files,the laboratory model test in order to analyze the elementary effects of geotextile reinfor- cement and the finite element program analyzing the stresses and deformations characteristics was carried out. A two-dimensional nonlinear finite element program called GEOTEXT(a modification of ISBILD) for the static analysis of embankment on very soft foundation reinforced geotextiles has been developed. Both linear and nonlinear hyperbolic stress-strain soil models are inclu- ded, and incremental and stage construction can be simulated. However, the program GEO- TEXT is not developed herein as an adaptable design tool for practicing engineer. It was found that the geotextile reinforcement significantly reduced the shear stresses in the foundation and decreased the vertical differential settlements at the top of the embank- ment. This influence was more pronounced as the tensile strength of the geotextile was increased.

• The KIPS Transactions:PartA
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• v.18A no.5
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• pp.193-204
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• 2011

Since web applications are accessed by anonymous users via web, more security risks are imposed on those applications. In particular, because security vulnerabilities caused by insecure source codes cannot be properly handled by the system-level security system such as the intrusion detection system, it is necessary to eliminate such problems in advance. In this paper, to enhance the security of web applications, we develop a static analyzer for detecting the well-known security vulnerability of PHP file inclusion vulnerability. Using a semantic based static analysis, our vulnerability analyzer guarantees the soundness of the vulnerability detection and imposes no runtime overhead, differently from the other approaches such as the penetration test method and the application firewall method. For this end, our analyzer adopts abstract interpretation framework and uses an abstract analysis domain designed for the detection of the target vulnerability in PHP programs. Thus, our analyzer can efficiently analyze complicated data-flow relations in PHP programs caused by extensive usage of string data. The analysis results can be browsed using a JAVA GUI tool and the memory states and variable values at vulnerable program points can also be checked. To show the correctness and practicability of our analyzer, we analyzed the source codes of open PHP applications using the analyzer. Our experimental results show that our analyzer has practical performance in analysis capability and execution time.

• Explosives and Blasting
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• v.36 no.3
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• pp.10-18
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• 2018

The dynamic behaviour of the rock mass under the dynamic load is different from the static application of the maximum load of the same size. An experimental approach to investigating rock behavior under dynamic loads is more difficult than that under static conditions in control of dynamic loads, measurement and analysis of the results. Numerical methods are less constrained by performing the experiments numerically, rather than experimental ones, so they can be very powerful analytical tool at the design stage. However, even if the algorithms of the analysis method are appropriate, careful analysis is required because the calculation results may vary largely depending on input data and boundary conditions. In this paper, when investigating the behavior of rock structures under dynamic load numerically, the effects of boundary conditions, dynamic load and calculation time step, and dynamic load characteristics on the calculation results were reviewed to provide guidance on setting up boundary conditions and calculation time step related to dynamic analysis.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.813-818
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• 2020

This study is a study on the characteristics and analysis of the reflected signals about the target in the VHF band. In advance, the RCS(Radar Cross Section) characteristics of the target were analyzed by using the CST electromagnetic analysis tool, and the target was detected by using the Bi-Static method, and the change in the signal-to-noise ratio was tested. The test results show similar results with no significant fluctuations in the signal-to-noise ratio characteristics for the detection of signals reflected on the target, such as the results for RCS analysis according to the pre-incidence angle. In the future, this study will be used for RCS analysis of the targets and target detection of Radar in VHF/UHF band with relatively large wavelength compared to the X band.

• KIISE Transactions on Computing Practices
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• v.22 no.4
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• pp.178-183
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• 2016

To enhance the reliability of programs, developers use fuzzing tools in test processes to identify vulnerabilities so that they can be fixed ahead of time. In this case, the developers consider the security-related vulnerabilities to be the most critical ones that should be urgently fixed to avoid possible exploitation by attackers. However, developers without much experience of analysis of vulnerabilities usually rely on tools to pick out the security-related crashes from the normal crashes. In this paper, we suggest a static analysis-based tool to help developers to make their programs more reliable by identifying security-related crashes among them. This paper includes experimental results, and compares them to the results from MSEC !exploitable for the same sets of crashes.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.127-133
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• 2007

The spindle system with a built-in motor can be used to simplify the structure of machine tools, to improve the machining flexibility of machine tools, and to perform the high speed machining. To improve the competition power of price to quality, spindle design is very important. Because it possesses over 10 percent of machine tool's price. The latest machine tools have rotational frequency and excellent about might and precision cutting. So it requires static and dynamic strength in the load aspect. In conclusion, the deformation of the spindle end have to extremely small displacement in static and dynamic load. In this study, On the assumption that the bearings that are supporting 24,000rpm high-speed spindle are selected in the most optimum condition, the natural frequency and deformation of the spindle end is obtained by FEM mode analysis. The Taguchi Method was used to draw optimized condition of bearing position and it's stiffness.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.127-134
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• 2004

As the result of reduction of the barrier of national economy on matters of quality assurance of weighing instruments in recently, it is considering in domestic as well as international matters. Therefore, this study is to analysis and compare with international md national measuring standards on the electric self-indicating scale, to improve the quality of electronic machine by providing a reformation plan on currently problems of domestic manufactured, and to identify to introduce in domestic criteria from international standards. I had compared KSC 1313 to OIML R 76-1 as the performance assessment items, such as metrology Properties test, static temperature test, temperature effect testing under the un-load, electronic wave disturbance test, high-tempereature and high-humidity stability test and durability test. Therefore, only one company is passed all items of the test according to the international (reference) standards, but it is possible to improve the quality in general if it should be use the load cell and electric components which is stability of temperature change in order to supplementation to the static temperature test and temperature effect testing under the un-load. It is also possible to apply in the domestic with the OIML 76-1 after correcting the design.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.65-71
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• 2002

Friction welding has may merits such as energy efficiency, simple processing, etc. but it is difficult to obtain good welding at the welded interfaces and heat affected zone. It is discovered that stress singularity exists at the interferes and heat affected zone. The computer program based on boundary element method is utilized in this study. A mathematical model is implemented based on results from several experiments performed at and around the welded interfaces and heat affected zone of disimilar metals under static and dynamic loadings. This stay is to investigate the characteristics of the deformation and fracture behavior around interfaces for friction welded materials under static tensile load. Also, the stress distribution at the tip of crack is analyzed by using BU based on Kelvin's solution of 2-dimensional binding zone. The results of BEM are identical with those in case of considering interfaces of both heat affected zone. Also, stress singularity at the tip of interfaces appears when the elastic modulus ratio is 1.07.