• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.97-105
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• 1998

The fiber oriented condition inside fiber reinforced composite material is a basic factor of mechanical properties of composite materials. It is very important to meausure the fiber orientation angle for the determination of molding conditions, mechanical characteristics, and the design of composite materials. In the work, the fiber orientation distribution of simulation figure plotted by PC is measured using image processing in order to examine the accuracy of intersection counting method. The fiber orientation function measured by intersection counting method using image processing is compared with the calculated fiber orientation function. The results show that the measured value of fiber orientation function using intersection counting method is lower than the calculated value, because the number of intersection between the scanning line and the fiber with smaller fiber aspect ratio is counted less than with larger fiber aspect ratio.

• Korean Journal of Computational Design and Engineering
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• v.8 no.4
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• pp.278-288
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• 2003

Presented in this paper is a numerical method for calculating the intersection points between Z-map vectors and the tool swept surface for circularly moving filleted-end mills. In numerically controlled(NC) machining simulation for large moulds and dies, a workpiece is frequently approximated as a set of z-axis aligned vectors, called Z-map vectors, and then the machining processes can be simulated through updating the Z-map with the intersection points. Circular motions are typically used for machining the free-form surfaces. For fast computation, we express each of intersection points with a single-variable non-linear equation and calculate the candidate interval in which the unique solution exists. Then, we prove the existence of a solution and its uniqueness in this candidate interval. Based on these properties, we can effectively apply numerical methods to finally calculate the solution of the nonlinear equation within a given precision. Experimental results are given for the case of a TV monitor and the hood of a car.

• Korean Journal of Computational Design and Engineering
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• v.4 no.1
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• pp.43-51
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• 1999

Producing the relevant information (features) from the CAD models of CAM, called feature recognition or extraction, is the essential stage for the integration of CAD and CAM. Most feature recognition methods, however, have problems in the recognition of intersecting features because they do not handle the intersection geometry properly. In this paper, we propose a machining feature recognition algorithm, which has a solid model consisting of orthogonal primitives as input. The algorithm calculates candidate features and constitutes the Intersection Geometry Matrix which is necessary to represent the spatial relation of candidate features. Finally, it recognizes machining features from the proposed candidate features dividing and growing systems using half space and Boolean operation. The algorithm has the following characteristics: Though the geometry of part is complex due to the intersections of design primitives, it can recognize the necessary machining features. In addition, it creates the Maximal Feature Volumes independent of the machining sequences at the feature recognition stage so that it can easily accommodate the change of decision criteria of machining orders.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1424-1428
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• 2004

A new design for deburring tools for intersecting holes is introduced. The tool tip is mounted on a slender cantilever assembled into a circular shank. The tool tip has been design to cover ranges of exit angle and diameter ratio between intersecting holes. The design is an improvement over the previous ones by the authors. Experiments have been performed on AL6061. With the new design, mild exit burrs with exit angles greater than 45$^{\circ}$ are successfully removed. For large burrs with smaller exit angles, however, the deburring could be incomplete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.41-48
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• 2009

The capacity analysis of signalized intersection usually includes a HCM method used at home and abroad and a ICU method this study presents. The HCM method focuses on operation analysis measuring an intersection's delay in terms of given traffic volume, signal operation, and intersection structure data. This method includes planning and design analysis, but these analyses are complex due to being possible through repetitive operation analysis. However the ICU method is a powerful tool for planning and design analysis, because these are possible through brief traffic volume and geometry structure data and consider minimum green time. In this study, the authors studied the ICU method and compared the HCM and ICU by analyzing traffic volume scenarios. Also to consider effectiveness for application of the ICU method, the authors applied the ICU to capacity analysis of intersections on urban arterial for setting major intersection and effect analysis for changing crosswalk type, the number of lane, lane use and operation form of left turn. The result of the analyses shows that the ICU method can measure correct capacity of intersection consist of a broad road in urban area, and is effective for planning and design analysis. This study is expected that traffic experts can grasp correct intersection's capacity and carry out a proper planning or improvement by applying the ICU method to planning and design analysis.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.23-28
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• 2002

This paper presents an efficient line-offset algorithm for general polygonal shapes with islands. A developed sweep-line algorithm (SL) is introduced to find all self-intersection points accurately and quickly. The previous work is limited to handle polygons that having no line-segments in parallel to sweep-line directions. The proposed algorithm has been implemented in Visual C++ and applied to offset point sequence curves, which contain several islands.

• Journal of Korean Society of Transportation
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• v.1 no.1
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• pp.56-63
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• 1983

Intersection control has dual-purposes; increasing capacity and reducing delay. The primary concern of efficient intersection control under oversaturated condition as in Korea is to increase capacity. Prevailing intersection operation technique permits thru traffic to utilize left turn lane, because the intersection without left turn pocket has left turn signal interval. In this situation, it seems not to be valid to calculate capacity, delay, and signal timings by conventional methods. By critical lane technique, capacity increases as cycle length increases. However, when thru traffic utilize LT lane, the capacity varies according to LT volume, LT interval as well as cycle length, which implies that specific cycle length and LT interval exist to maximize capacity for given LT volume. The study is designed is designed to calculate utilization factors of LT lane for thru traffic and capacities, and identify signal timings to yield maximum capacity. The experimental design involved has 3 variables; 1)LT volumes at each approach(20-300 vph), 2)cycle lengths (60-220 sec), and 3)LT intervals(2.6-42 sec) for one scenario of isolated intersection crossing two 6-lanes streets. For LT volume of 50-150 vph, capacity calculated by using the utilization factor is about 25% higher than that by critical lane method. The range of optimum cycle length to yield maximum capapcity for LT volume less than 120 vph is 140-180 sec, and increases as LT volume increases. The optimum LT interval to yield maximum capacity is longer than the intrval necessary to accommodate LT volume at saturation flow rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2906-2910
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• 2015

The alignment modifications after completion of railway construction entail a lot of efforts and time as well as high additional costs. In the process of renewal of the existing railway alignment to offer higher-speed services, the effect of initial design parameters(e.g., intersection angle) on determination of allowable degree of improvement of horizontal curves under consideration of economic efficiency is investigated in this study. From the analysis results, in the case that there are obstacles at the tangent line, it was found that the larger angle of intersection has a significant effect on the permissible zone. In addition, as the intersection angle is increased, the permissible values of maximum curve radius and the length of transition curve becomes smaller and longer, respectively. It is expected that this study can contribute to the efficient and accurate prediction of the permissible zone according to the locations of obstacles and the size of intersection angle as well as improvement in the railway alignment without any additional costs.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.7-16
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• 2008

Severe congestion is happening at urban freeway off-ramps in Seoul. Major causes of congestion at off-ramps are a shortage of capacity and inefficient signal operations at the downstream intersection at off-ramps. It is necessary to control congestion by improving design or operations in the downstream intersection. In this study, the authors analyzed the case of the Jungdong interchange that was improved for design in the downstream intersection. When a freeway and an arterial road cross, diamond interchanges are usually selected with a single-point urban interchange (SPUI) as an alternative. To compare the effectiveness of a diamond interchange with a SPUI, the authors applied these two configurations to the Jungdong interchange using a simulation. The result of the analysis shows that congestion at off-ramps in diamond interchanges can be reduced by improving signal operations such as the application of "4 phase with overlaps" and that diamond interchanges are more efficient than a SPUI with a frontage road. Efficient operation of the downstream intersection by these findings can minimize congestion of not only the downstream intersection but also the freeway mainline.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.155-156
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• 2012