• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.641-649
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• 2001

A procedure of detecting change-points is considered with split linear fitting idea from Hall and Titterington(1992). At each given point, left, central and right linear fits are compared to detect the discontinuities or change-points. A simulation study is done with various types of change models and shows that the suggested technique can be a flexible data-analytic tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.208.1-212
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• 1997

In this paper, a computer simulation tool for evaluting integrated engine/transmission control system using MATLAB/SIMULINK is investigated. Since a modular programming technique based upon the object-oriented programming is used in the paper, the simulation tool developed reduces the burden of model complexity by dividing engine/transmission systems into hierarchical subsystem. Furthermore, it also provides user -friendly, reusable, and upgradable characteristics of the system. The simulation tool could be useful to the automotive engineers who frequently change models and develop new systems in the automotive powertrain and control area.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.332-335
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• 1997

With the advance of precision technique, the optical system is more precise and complex and the machining method of optical element which is composed of micro-grooves is developed. Especially, the method of micro-grooving using diamond tool is used widely owing to many merit, but has problems of damage of surface roughness due to tool wear and tool fracture. This paper deals with state monitoring using AE RMS in the micro-grooving. The change of AE RMS is very small with increment of cutting velocity and depth of cut. In spite of constance magnitude of principal force in machining using diamond tool of tool wear and tool fracture, AE RMS is highly fluctuated. Because changing of cutting state has relevance to surface roughness profile, surface toughness profile is expected using AE RMS.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.348-352
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• 1992

At present, the manufacturing industry is in a process of great change of circumstances like meeting demands to involve a great variety of types and shorter product life and thus more flexible manufacturing. These changes cause the larger number of different tools and frequent tool changes, which lead to the considerable losses in productive time and the high amount of capital tied up in the tool area. In our country, for the most part, the individual tool are still being presetted according to a data sheet and the measured values are entered, output in a list manually or via punched tapes. This usually takes a considerable amount time and lead to a high error rate. This paper describes a computer controlled tool data management system combined with the bar code tool identification labeled on cutting tools.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.39-46
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• 2003

Productivity and machining performance can be improved by cutting analysis including cutting force prediction, surface error prediction and machining stability evaluation. In order to perform cutting analysis, cutting force coefficients database have to be constructed. Since cutting force coefficients are dependent on cutting condition in the existing research, a large number of calibration tests are needed to obtain cutting force coefficients, which makes it difficult to build the cutting force coefficients database. This paper proposes a generalized method for constructing the cutting force coefficients database us ins cutting-condition-independent coefficients. The tool geometry and workpiece material were considered as important components for database construction. Cutting force coefficients were calculated and analyzed for various helix and rake angles as well as for several workpiece. Furthermore, the variation of cutting force coefficients according to tool wear was analyzed. Tool wear was found to affect tool geometry, which results in the change of cutting force coefficients.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.128-135
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• 2018

The various video recording device, like car black box and cctv, are used currently and video contents are used as evidence of traffic accidents and scenes of crime. To verify integrity of video content, there are various study on manipulated video content analysis. Among these studies, a study based on analysis of video file structure and its variables needs a tool which can be used to analyze file structure and extract interested attributes. In this paper, we proposed design and implementation of an analyzing tool which visualizes video file structure and its attributes. The proposed tool use a model which reflects commonality of various video container format, so it is available to analyze video structure with regardless of the video file types. And the tool specifies interested file structure properties in XML and therefore we can change target properties easily without modification of the tool.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.90-96
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• 2021

As real-time data of factories can be collected using various sensors, the adaptation of intelligent unmanned processing systems is spreading via the establishment of smart factories. In intelligent unmanned processing systems, data are collected in real time using sensors. The equipment is controlled by predicting future situations using the collected data. Particularly, a technology for the prediction of tool wear and for determining the exact timing of tool replacement is needed to prevent defected or unprocessed products due to tool breakage or tool wear. Directly measuring the tool wear in real time is difficult during the cutting process in milling. Therefore, tool wear should be predicted indirectly by analyzing the cutting load of the main spindle, current, vibration, noise, etc. In this study, data from the current and acceleration sensors; displacement data along the X, Y, and Z axes; tool wear value, and shape change data observed using Newroview were collected from the high-speed, two-edge, flat-end mill machining process of SKD11 steel. The support vector machine technique (machine learning technique) was applied to predict the amount of tool wear using the aforementioned data. Additionally, the prediction accuracies of all kernels were compared.

• Design & Manufacturing
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• v.14 no.4
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• pp.46-51
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• 2020

The purpose of this study was to analyze the change in tensile strength characteristics of the weld when the welding speed and rotational speed of the tool, which are representative variables of the friction stir welding process. The equipment used in the experiment was Machining Center No. 5. The material used in the experiment is an AA6061-T6 alloy, and a rolled plate with a thickness of 2mm was used. Two experimental variables were selected, the welding speed of the tool and the rotational speed of the tool. The experimental conditions were selected in the range in which a healthy weld could be obtained through a preliminary experiment. The welding speed of the tool was increased to 100mm/min, 200mm/min, and 300mm/min, and the rotational speed of the tool was increased to 1000rpm, 2000rpm, and 3000rpm. As a result of the experiment, the tensile strength increased as the rotational speed of the tool changed at each tool welding speed. In addition, as the welding speed of the tool increased, the tensile strength of the weld was increased. The condition with the highest tensile strength of the weld was found to be a tool feed speed of 300 mm/min and a tool rotation speed of 3000rpm.

• Design & Manufacturing
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• v.18 no.2
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• pp.51-56
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• 2024

In this study, a tool was developed for analyzing production lead time in turning operations. It is expected to help to reduce machining time and to identify, for example, tool change intervals. The tool was developed using Visual Basic.Net and features a user-friendly graphical user interface (GUI) that allows users to easily input cutting conditions and calculate the usage time and feeding distance for each cutting tool based on a G-code program. Object-oriented programming techniques were also used to encapsulate and classify complex logic, thereby efficiently organizing and managing the functions and data structures of this analysis tool. The analysis tool provides various outputs. It calculates the use time of each detailed process of the turning operation, the use time of each tool, the use time of each type of feeding, and also generates the data needed for cutting time analysis, which can be visualized in charts. The analysis tool developed in this study is expected to significantly contribute to improving the efficiency of manufacturing processes and increasing productivity, particularly, in the manufacturing of components requiring massive material removal, such as aircraft parts.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.275-285
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• 2017

Chungnam region has established and executed the 2nd Climate Change Adaptation Initiative Execution Plan (2017~2021) based on the Framework Act on Low Carbon, Green Growth. The Execution Plan is established based on the results of climate change vulnerability assessment using the CCGIS, LCCGIS, and VESTAP analysis tools. However, the previously developed climate change vulnerability assessment tools (CCGIS, LCCGIS, VESTAP) cannot reflect the local records and the items and indices of new assessment. Therefore, this study developed a prototype of climate change vulnerability assessment analysis tool that, unlike the previous analysis tools, designs the items and indices considering the local characteristics and allows analysis of grid units. The prototype was used to simulate the vulnerability to forest fires of eight cities and seven towns in Chungcheongnam-do Province in the 2010s, 2020s, and 2050s based on the RCP (Representative Concentration Pathways) 8.5 Scenario provided by the Korea Meteorological Administration. Based on the analysis, Chungcheongnam-do Province's vulnerability to forest fires in the 2010s was highest in Seocheon-gun (0.201), followed by Gyeryong-si (0.173) and Buyeo-gun (0.173) and the future prospects in the 2050s was highest in Seocheon-gun (0.179), followed by Gyeryong-si (0.169) and Buyeo-gun (0.154). The area with highest vulnerability to forest fires in Chungcheongnam-do Province was Biin-myeon, Seocheon-gun and the area may become most vulnerable was Pangyo-myeon, Seocheon-gun. The prototype and the results of analysis may be used to establish the directions and strategies in regards to the vulnerability to wild fires to secure each local government's 2nd execution plan and attainability.