• Korean Journal of Computational Design and Engineering
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• v.4 no.2
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• pp.110-120
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• 1999

In general, turbine blades are usually machined on 5-axis NC machine. The 5-axis machining of sculptured surface offers many advantages over 3-axis machining including the faster material-removal rates and an improved surface finish. But it is difficult and time-consuming to generated interference-free 5-axis tool path. This paper describes research on the algorithm for generation of an interference-free 5-axis NC data for machining turbine blades. The approach, using the section profile derived from the intersection of cutting planes with a triangulated-surface approximation, includes (1) CL-data generation by detecting an interference-free heel angle (2) the calculation method for finding a adaptive feed-rate value, and (3) the inverse kinematics depending on the structure of 5-axis machine.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.11
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• pp.77-83
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• 1997

This work is concerned with the algorithm of generating a new circular are interpolation. This research presents a new biarc curve fitting that is a circular interpolation method based on a triarc curve fitting. The triarc method, where a segment span is composed of three circular arcs, using maximum error estimation has the advantage of generating arc splines easily to a given tolerance. The new biarc method is called when the adjacent radii are the same in the same in the triarc method. In generating the machining data for various cam curves in CNC machining with the biarc method and the new biarc method, the latter accomp- lished faster NC-code generation, shorter NC-code block formation and machined the same cam profile more efficiently.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.901-908
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• 1988

In machining die cavities or mechanical parts, we often encounter the needs to remove a material within a given boundary. Even though this pocket cutting capability has been implemented in many NC packages, most of them can handle convex shaped pockets bounded by curves of limited types and numbers. In this work, a procedure has been developed to machine pockets of a free surface bounded by lines, circular arcs and free curves. Also, the cutter location data is computed directly without using iterative method for better computational efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.256-261
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• 1992

Acquisition of 3D points is an essential process for modelling of physical 3D objects. Although Coordinate Measuring Machine(CMM) is most accurate for this purpose, it is very time consuming. To enhance the data aquisition speed for scuptured surfaces, active vision with reflecctometric method was used for our system. A fter the data acquisition, the system automatically generates cutting tool path for the 3-axis milling of the object. The fullyintegrated system from the data acquisition to the NC-code generation was implemented with IBN-PC/386 and necessary hardwears.

• Journal of Korea Game Society
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• v.15 no.4
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• pp.29-38
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• 2015

In the stealth game design, level designers are to develop many interesting game environments with a variety of difficulties. J. Tremblay and his co-authors developed a Unity-based level design tool to help and automate this process. Given a map, if the designer inputs several game factors such as guard paths and velocities, their vision, and the player's initial and goal positions, then the tool visualizes simulation results including (clustered) possible paths a player could take to avoid detection. Thus with the help of this tool, the designer can ensure in realtime if the current game factors result in the intended difficulties and players paths, and if necessary adjust the factors. In this note, we present our improvement on this tool in two aspects. First, we integrate a function that if the designer inputs some vertices in the map, then the tool systematically generates and suggests interesting guard paths containing these vertices of various difficulties, which enhances its convenience and usefulness as a tool. Second, we replace the collision-detection function and the RRT-based (player) path generation function, by our new collision-check function and a Delaunay roadmap-based path generation function, which remarkably improves the simulation process in time-efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.529-530
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• 2006

Manufacturing industry is changing rapidly. Prototyping with rapid manufacturing is a part of every business in many companies and prototypes are used efficiently as a part of the production development process. Sheet metal forming has traditionally been a technology area where prototyping has been extremely expensive and efficient options for low volume have been limited. This paper describes the process for incremental sheet forming technologies to make the prototype for a brake dust shield of vehicles, which includes the remodeling method to make a base mold and tool path for sheet metal forming and 5-axes laser cutting machine to trim the prototype product.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5723-5743
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• 2018

The evolving internet-based services demand high-speed data transmission in conjunction with scalability. The next generation optical network has to exploit artificial intelligence and cognitive techniques to cope with the emerging requirements. This work proposes a novel way to solve the dynamic provisioning problem in optical network. The provisioning in optical network involves the computation of routes and the reservation of wavelenghs (Routing and Wavelength assignment-RWA). This is an extensively studied multi-objective optimization problem and its complexity is known to be NP-Complete. As the exact algorithms incurs more running time, the heuristic based approaches have been widely preferred to solve this problem. Recently the software-defined networking has impacted the way the optical pipes are configured and monitored. This work proposes the dynamic selection of path computation algorithms in response to the changing service requirements and network scenarios. A software-defined controller mechanism with a novel packet matching feature was proposed to dynamically match the traffic demands with the appropriate algorithm. A software-defined controller with Path Computation Element-PCE was created in the ONOS tool. A simulation study was performed with the case study of dynamic path establishment in ONOS-Open Network Operating System based software defined controller environment. A java based NOX controller was configured with a parent path computation element. The child path computation elements were configured with different path computation algorithms under the control of the parent path computation element. The use case of dynamic bulk path creation was considered. The algorithm selection method is compared with the existing single algorithm based method and the results are analyzed.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.1
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• pp.50-54
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• 2004

Reference trajectory generation plays a key role in the computer control for accurate position control of machine. Generated trajectories must not only describe the desired tool path accurately, but must also have smooth kinetic profiles in order to maintain higher tracking accuracy, and to avoid exciting the natural modes of the mechanical servo control system. To achieve higher accurate position control, a method of limiting accelerating and decelerating speed data of reference trajectories is proposed to draw the path with an assigned accuracy without any complex operations.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.539-547
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• 2011

In this paper, a method of generating path planning map is developed using digitalized geographic information such as FDB(Feature DataBase). FDB is widely used by the Army and needs to be applied to all weapon systems of newly developed. For the autonomous navigation of a robot, it is necessary to generate a path planning map by which a global path can be optimized. First, data included in FDB is analyzed in order to identify meaningful layers and attributes of which information can be used to generate the path planning map. Then for each of meaningful layers identified, a set of values of attributes in the layer is converted into the traverse cost using a matching table in which any combination of attribute values are matched into the corresponding traverse cost. For a certain region that is gridded, i.e., represented by a grid map, the traverse cost is extracted in a automatic manner for each gird of the region to generate the path planning map. Since multiple layers may be included in a single grid, an algorithm is developed to fusion several traverse costs. The proposed method is tested using a experimental program. Test results show that it can be a viable tool for generating the path planning map in real-time. The method can be used to generate other kinds of path planning maps using the digitalized geographic information as well.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.112-117
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• 2016

In the construction industry, concrete polishing is used to grind and rub the surface of concrete grounds with polishing machines to increase the strength of the concrete after deposition. Polishing is performed manually in spite of the generation of dust and the requirement of frequent replacements of the polishing pad. The concrete polishing robot developed in this research is a novel polishing automation system for preventing the workers from being exposed to poor working environments. This robot is able to change multiple polishing tools automatically; however, the workers can conveniently replace the worn-out polishing pads with new ones. The mobile platform of the polishing robot employs omnidirectional wheels to enable a flexible motion even in small and complicated workspaces. To evaluate the performance of the developed concrete polishing robot, extensive experiments including square trajectory tracking, automatic tool changing, actual polishing, and path generation simulation were performed.