• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.6
• /
• pp.35-42
• /
• 2002

Verification of tool collision Is an important issue in die and mold machining. In this paper three functions of verification for 3-axis milling machining are schematically explained. Operators of geometric models are explained at first, which will be used in the functions of verification. The first verification function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Proposed approaches can be easily implemented by using several basic operators of geometric model. An example to calculate collision-free region is presented also.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.123-130
• /
• 2007

In this paper, We define convert rules from objects and relation presented in object model to the state and operation domain in formal specification. Namely, object and relation in information model converted to state domain in formal specification. State, event and behavior converted to operation domain. And that way informal object model change to formal language, it can be verify through formal method. Verification process make an offer convenience and confidence in software development early phase. And we implement simulation tool in order to verification method of formal specification and to consistency verified model between user's requirement. It is possible to select the suitable model and reduce the costs and efforts on software development.

• Journal of Electrical Engineering and Technology
• /
• v.1 no.4
• /
• pp.513-519
• /
• 2006

As a very important part in development of the protocol, verifications for developed protocol specification are complementary techniques that are used to increase the level of confidence in the system functions by their specifications. Using the informal method for specifying the protocol, some ambiguity may be contained therein. This indwelling ambiguity in control systems can cause the occurrence of accidents, especially in the case of safety-critical systems. To clear the vagueness contained in the designed protocol, we use the LTS (Labeled Transition System) model to design the protocol for railway signaling. And then, we verify the safety and the liveness properties formally through the model checking method. The modal ${\mu}$-calculus, which is an expressive method of temporal logic, has been applied to the model checking method. We verify the safety and liveness properties of Korean standard protocol for railway signaling systems. To perform automatic verification of the safety and liveness properties of the designed protocol, a communication verification tool is implemented. The developed tools are implemented by C++ language under Windows XP. It is expected to increase the safety and reliability of communication protocol for signaling systems by using the developed communication verification tool.

• The Journal of the Acoustical Society of Korea
• /
• v.29 no.3
• /
• pp.216-221
• /
• 2010

In this paper, we propose speaker verification method using Support Vector Machine (SVM) kernel with Gaussian Mixture Model (GMM)-supervector based on the Mahalanobis distance. The proposed GMM-supervector SVM kernel method is combined GMM with SVM. The GMM-supervectors are generated by GMM parameters of speaker and other speaker utterances. A speaker verification threshold of GMM-supervectors is decided by SVM kernel based on Mahalanobis distance to improve speaker verification accuracy. The experimental results for text-independent speaker verification using 20 speakers demonstrates the performance of the proposed method compared to GMM, SVM, GMM-supervector SVM kernel based on Kullback-Leibler (KL) divergence, and GMM-supervector SVM kernel based on Bhattacharyya distance.

• Journal of Korea Multimedia Society
• /
• v.25 no.10
• /
• pp.1416-1432
• /
• 2022

The access control system is a system that allows users to selectively enter the building by granting an access key to the user for security. Access keys with weak security are easily exposed to attackers and cannot properly perform the role that authenticates users. Access code keys should be protected from forgery or spoofing. For this reason, access key verification service models is important in security. However, most models manage all access keys on one central server. This method not only interrupts all services due to server errors, but also risks forgery and spoofing in the process of transmitting access keys. Therefore, blockchain algorithms are used to reduce this risk. This paper proposes a blockchain-based access key verification service model that used distributed stored blockchain gateways on storing access keys and authenticates the user's identity based on them. To evaluate the performance of this model, an experiment was conducted to confirm the performance of the access key forgery recovery rate and the blockchain network performance. As a result, the proposed method is 100% forgery recovery rate, and the registration and verification process is evaluated at 387.58 TPS and 136.66 TPS.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.12
• /
• pp.86-92
• /
• 2002

This paper presents a new model of NC verification in NC milling using z-map. The model can describe the motion of machine tool like a real machine effectively. The model uses x, y, and z directional feed rate as well as cutting data for modeling Z-map of workpiece. The model verifies the over-cut, the under-cut and the surface topography using NC codes and cutting conditions. To investigate the performance of the model, simulation study was carried out. As the results, the model gave the geometry accuracy of workpiece, the surface topography, and the chip loads.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.05a
• /
• pp.725-729
• /
• 2000

This paper presented a new model of NC verification in ball end milling. The model verifies the over cut the under cut and the surface roughness using NC file generated from CAM and cutting condition. The model uses Z-map model to verify workpiece. In this paper, the model used the velocities of x, y and z direction and obtained a center point of a ball end mill for modeling Z-map of workpiece. To investigate the performance of the model simulation study was carried out. As the results, the model gave geometry accuracy of workpiece, the surface roughness and the chip loads in finish cutting that can predict tool chipping.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.2
• /
• pp.267-274
• /
• 2002

Using a flexible rotating beam test bed, experimental verification of a flexible multibody dynamic simulations for a rotating beam model has been carried out. The test bed consists of a flexible arm, harmonic driver reducer, AC servo motor and DSP board with PC. The mechanical ports of the test bed has been designed using 3D CAD program. For the simulation model, mass and moment of inertia of each part of the flexible rotating beam test bed are also obtained from 3D CAD model. In the flexible multibody dynamic simulations, the substructuring model has been established to capture nonlinear effects of the flexible rotating beam. Through the experimental verification, substructuring model provides better results than those from the linear model in the high speed rotation.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.7
• /
• pp.1555-1562
• /
• 1995

This study represents the non-dimensional cutting force model. With the non-dimensional cutting force model it is possible to estimate efficiently the maximum cutting force during one revolution of cutter. Using the non-dimensional cutting force model, the feed rate and spindle speed are adjusted so as to satisfy the maximum cutting force and maximum machining error. To verify the accuracy and efficiency of the non-dimensional cutting force model, a series of experiments were conducted, and experimental results proved and verified the non-dimensional cutting force model. The NC toolpath verification system developed in this paper uses the non-dimensional cutting force model, so that it is effective for calculating the cutting force and adjusting the cutting conditions.

• Proceedings of the KSME Conference
• /
• 2001.06c
• /
• pp.116-121
• /
• 2001

Verification of tool collision is an important issue in die and mold machining. In this paper three functions of verification are schematically explained based on Z-Map model. The first function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision. The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Those functions can be easily implemented by using several basic operators of Z-Map model which are explained also. Proposed approaches have enough accuracy to verify collision in reasonable computing time.