• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.189-198
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• 1998

Recently, monitoring of tool life is a matter of common interesting because tool life affects precision, productivity and cost in machining process. Especially flank wear has a direct effect on cutting mechanism, so the various pattern of cutting force is obtained experimentally according to variation of wear condition. By investigating cutting force signal, AR(Autoregressive) modeling and correlation dimension analysis is conducted in turning operation. In this modeling and analysis, we extract features through 6th AR model, correlation integral and normalized correlation integral. After the back-propagation model of the neural network is utilized to monitor tool life according to flank wear. As a result. a very reliable classification of tool life was obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.195-206
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• 1997

In this study, a simulation tool is developed in order to investigate non steadystate cornering performance of 4WD/4WS vehicles. The 4WD/4WS vehicles are modeled as a 8-th order dynamic system which includes complex non-linear vehicle dynamics and tire models. The vehicle models are constructed into a modulated simulation tool and are utilized for analyzing cornering performance such as combined braking and steering, cornering on the icy read and $\mu$-split braking, The whole analysis is done with the simulation tool which consists of a number of subsystems and offers graphic environment. Simulation results show that this tool is useful and cost-effective in the dynamic analysis of the combustion-engine vehicles as well as electrically driven vehicles.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.70-75
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• 2008

This paper describes a tool-clamping/unclamping mechanism for application of a micro-spindle. The mechanism is based on one-way shape memory effect and interference-fit. The corresponding mathematical models and a few considerable design parameters are mentioned in this paper. Especially, necessary conditions for the clamping and unclamping operation are investigated through finite element analysis. The analysis results show that the differences between the diametral deformations of the tool holder in high temperature and that in low temperature are increased according to amounts of the interference. Thus the less interference between the tool-holder and the ring, the less tolerance to allow the clamping and unclamping operation because the inner diameter of the tool holder in high temperature should be smaller than the diameter of the tool shank, and that in low temperature should be larger than the diameter of the tool shank. In addition, the design for maximization of clamping force are investigated based on finite element analysis. The results show that the more amounts of the interference, the more clamping force. As the result, the interference should be considered as a important factor to maximize the tool clamping force.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.2
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• pp.162-169
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• 2009

This paper describes a study on dynamic characteristics analysis and dynamic compliance evaluation of a 5-axis multi-tasking machine tool of ram-head type. Structural dynamics analysis and evaluation are necessary to machine tool design and development to secure good machine tool performance against tough and harsh machining conditions. In this study, natural frequencies and corresponding vibration modes of the machine tool structure were analyzed by using both F.E.M. modal analysis and impulse hammer test. Furthermore, dynamic compliance of the machine tool was analyzed by using F.E.M. and also measured by using a hydraulic exciter test. Both the theoretical analysis and experimental test results showed good agreement with each other.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.96-102
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• 2002

This study is on the estimation method of toot temperature for different tool nose radius and cutting conditions in turning. Experimental analysis has been performed in different cutting conditions such as cutting speed, feed rate, and depth of cut for the tool nose radius, 0.4R, 0.8R using SMC workpiece materials. Tool temperature is measured using a thermo-couple which is embedded in the insert tip. Using multiple linear regression method, the tool temperature can be determined as an exponential equation with cutting variables and tool nose diameters for the different tool materials. The equations determined in this study show a good correlation for the cutting conditions and can be used for a tool temperature estimation technique. The result indicates that the tool temperature decreases for increasing the tool nose radius in general. Also, nose radius hardly influences on the tool temperature compared with cutting speed, feed rate and depth of cut. This method will be useful for the estimation of tool life and temperature using limited experimental data for given cutting conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.898-901
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• 2000

In this paper, the theoretical tool displacement and surface roughness are analyzed based on the tool locus of a 2-dimensional tool vibrator. At first, the effects assuming no structural deformation of such variables as frequency, amplitude and phase difference that determine tool loci are simulated. The results show that larger amplitude and/or higher frequency makes better surface. However, a real tool vibrator has the structural deformation, much or less, depending on the excitation frequency. Applying FEM analysis to the deformation of a designed 2D tool vibrator according to the excitation, it has been proved that in this case the displacement is 5${\mu}{\textrm}{m}$ at 1KHz and almost 0 at 20KHz even under the same excitation amplitude.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.178-192
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• 2021

File system forensics typically focus on the contents or timestamps of a file, and it is common to work around file/directory centers. But to recover a deleted file on the disk or use a carving technique to find and connect partial missing content, the evidence must be analyzed using cluster-centered analysis. Forensics tools such as EnCase, TSK, and X-ways, provide a basic ability to get information about disk clusters, but these are not the core functions of the tools. Alternatively, Sysinternals' DiskView tool provides a more intuitive visualization function, which makes it easier to obtain information around disk clusters. In addition, most current tools are for Windows. There are very few forensic analysis tools for MacOS, and furthermore, cluster analysis tools are very rare. In this paper, we developed a tool named FACT (Forensic Analyzer based Cluster Information Tool) for analyzing the state of clusters in a HFS+ file system, for digital forensics. The FACT consists of three features, a Cluster based analysis, B-tree based analysis, and Directory based analysis. The Cluster based analysis is the main feature, and was basically developed for cluster analysis. The FACT tool's cluster visualization feature plays a central role. The FACT tool was programmed in two programming languages, C/C++ and Python. The core part for analyzing the HFS+ filesystem was programmed in C/C++ and the visualization part is implemented using the Python Tkinter library. The features in this study will evolve into key forensics tools for use in MacOS, and by providing additional GUI capabilities can be very important for cluster-centric forensics analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.121-126
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• 2015

In this research, a tool was developed for the rapid performance of three-dimensional finite element analysis (3D FEA) of a machine tool spindle system made of a shaft and bearings. It runs the FEA with data, such as the bearing stiffness and the coordinates of the points, to define the section of the shaft, bearing positions, and cutting point. developed for the spindle system and then implemented with the tool using an object-oriented programing technique that allows the use of the objects of the CAD system used in this research. Graphic user interfaces were designed for a user to interact with the tool. It provides rapid evaluation of the design of a spindle system, and therefore, it would be helpful to identify a near optimal design of a spindle system based on, say, static stiffness with design changes and, consequently, FEA.

• Korean Institute of Interior Design Journal
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• v.16 no.2 s.61
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• pp.314-321
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• 2007

The statistical method of human sensibility ergonomics is widely used for analyzing interior design because it has standard processes and it can help to get quantifiable results. However applying this method demands repeated intense work and great time and effort is required. In this study, a tool applying Web and virtual reality techniques for statistical human sensibility ergonomic interior design analysis is proposed and the key parts of the tool including database and interface are implemented. The database contains the sensibility adjective table and the physical interior design factor table for analyzing the relationship between human sense and physical design factors. Interface of the tool is implemented using Web technologies, so testers can evaluate interior design samples via standard Web browsers. The 3D control which is an important component of the interface is also implemented. Employing the suggested tool can reduce effort and time for evaluating human sense in Interior design field.

• Journal of Astronomy and Space Sciences
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• v.37 no.3
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• pp.187-197
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• 2020

In order to avoid the high cost and high risk of demonstration mission of rendezvous-docking technology, missions using nanosatellites have recently been increasing. However, there are few successful mission cases due to many limitations of nanosatellites like small size, power limitation, and limited performances of sensor, thruster, and controller. To improve the probability of rendezvous-docking mission success using nanosatellite, a rendezvous-docking phase analysis tool for nanosatellites is developed. The tool serves to analyze the relative position and attitude control of the chaser satellite at the docking phase. In this tool, the Model Predictive Controller (MPC) is implemented as a controller, and Extended Kalman Filter (EKF) is adopted as a filter for noise filtering. To verify the performance and effectiveness of the developed tool for nanosatellites, simulation study was conducted. Consequently, we confirmed that this tool can be used for the analysis of relative position and attitude control for nanosatellites in the rendezvous-docking phase.