• Journal of the Korean Society for Railway
• /
• v.19 no.6
• /
• pp.717-726
• /
• 2016

Emergency tracks are necessary in case a broken down train evacuates, a train needs to make way for a faster train behind it, or a train suddenly stops and following trains must avoid colliding with it. Magnetic Levitated (maglev) Trains can change track to enter an emergency track using a segmented switch or a traverse switch. On a traverse switch, a train can change its track when the part of the track that the train is on moves to the other track. Currently manufactured Maglev trains have two bodies and the total length is 25 meters. If a traverse switch is used, it will only require 30 meters of track to move the train to the other track, so, when it comes to efficiency of costs and space, the traverse switch surpasses the articulated switch. Therefore, in this paper, an optimized design to secure structural safety and weight lightening is suggested. To achieve these results, the heights of the piled concrete and girders which are both placed on the top of the traverse switch, are set as design variables. The Finite Element Method (FEM), in application of kriging and in the design of the experiments (DOE), is used. Maximum stress, deformation, and structural weight are compared with the results, and through this process structural safety and weight lightening is proven.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.3
• /
• pp.1-7
• /
• 2004

Abrasive water-jet(AWJ) machining can cut various materials such as metal, glass and plastics. However, the AWJ machining has some troubles including kerf, rounding and side taper. In this study, we experimently investigated the correlation between the traverse speed of the abrasive water-jet and the dimensional error of the workpiece according to the thickness and the types of the material. The specimen was the stainless steel and the mild steel and the predetermined contour cutting was conducted. A comer radius error, an uncut width and a kerf were measured and evaluated.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.323-327
• /
• 1995

A new air knife system for coating thickness control in hot dip galvanizing process had been developed and installed on the CGL in Pohang Steel Works, POSCO. This new system consists of air knives with remotely adjustable nozzle slot and an automatic control system which can control both longitudinal and traverse coating deviations. Based on the optimal control algorithm, a traverse coating deviation control was designed. The controller controls the lip profile of the air knives with flexible structure according to the deviation of coating weight. From the measured values which are dependent on the strip width, the lip gaps are calculated with optimal algorithm and the model of the coating deviation. Time delay between knives and a coating thickness gauge is solved by the Smith Predictor.

• The KIPS Transactions:PartD
• /
• v.12D no.6 s.102
• /
• pp.817-828
• /
• 2005

The main research problems in a mining frequent itemsets are reducing memory usage and processing time of the mining process, and most of the previous algorithms for finding frequent itemsets are based on an Apriori-property, and they are multi-scan algorithms. Moreover, their processing time are greatly increased as the length of a maximal frequent itemset. To overcome this drawback, another approaches had been actively proposed in previous researches to reduce the processing time. However, they are not efficient on a sparse .data set This paper proposed an efficient mining algorithm for finding frequent itemsets. A novel tree structure, called an $L_2$-tree, was proposed int, and an efficient mining algorithm of frequent itemsets using $L_2$-tree, called an $L_2$-traverse algorithm was also proposed. An $L_2$-tree is constructed from $L_2$, i.e., a set of frequent itemsets of size 2, and an $L_2$-traverse algorithm can find its mining result in a short time by traversing the $L_2$-tree once. To reduce the processing more, this paper also proposed an optimized algorithm $C_3$-traverse, which removes previously an itemset in $L_2$ not to be a frequent itemsets of size 3. Through various experiments, it was verified that the proposed algorithms were efficient in a sparse data set.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.246-251
• /
• 2001

This study is aimed to develop system that can export height automatically with Hierarchical Delaunay Triangulation and finally provide profile of hydraulic channel using 3D terrain geometry model. In this study, by using the object-oriented technique, we developed the traverse and cross-section design system of agricultural facilities, which maintain a consistency in the irrigation design process. This system can design the traverse and cross-section profile for the line type facilities. The results of this study, as for the design based on geography, after carrying out the modeling by using TIN of which employs Delaunays algorithm, it was found that the latitudinal design of the facility is feasible. And, as for the formulation of TIN, we obtained more precise result from using contour, stream, and road data rather than using the contour by itself.

• Journal of the Semiconductor & Display Technology
• /
• v.14 no.4
• /
• pp.30-37
• /
• 2015

This research aims to develop Look Ahead position interpolation algorithm for small size CNC machine controlled by PC based controller. Look Ahead scheme can process a bundle of CNC's linear interpolation commands simultaneously, which reduces acceleration and deceleration time within single linear interpolation command. The algorithm is derived as simple analytical form which can be adapted to PC based CNC system by C language programming. The performance of the algorithm was verified by tail stock machining G codes experimentally. The average traverse speed of the CNC machine was increased by 27.5% and the total traverse time also reduced by 27.2% with the Look Ahead scheme.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.24-32
• /
• 2007

Laser surface hardening is beneficially used for surface treatment of structural steel. Due to very rapid heating and cooling rates, structural low-alloy steel(SCM4) can be hardened as self quenching. The aim of this research project is to improve the influence of the process laser parameters: laser power, spot size, surface roughness, and traverse speed. The laser beam is allowed to scan on the surface of the workpiece at the constant power(1095W), varying the traverse speed at 0.3m/min, 0.5m/min and 0.8m/min. The optical lens with the elliptical profile is designed to obtain a wide surface hardening area with uniform hardness. From the results of the experiment, it has been shown that the stable hardness is about 600$\sim$700Hv, when the laser power, focal position and the traverse speed are P=1095W, z=0mm and v=0.3m/min.

• Economic and Environmental Geology
• /
• v.16 no.1
• /
• pp.11-18
• /
• 1983

Gyeongsang Basin in the southeastern part of the Korean peninsular is characterized by many fault systems. To decipher the geotectonical evolution of the Korean peninsular and marginal basins in her adjacent areas it is prerequisite to understand the spatial distribution pattern and mutual relationships of these fault systems. Because of difficulties in finding any criterion to recognize the faults in field, their extension and mutual relationships in ages are not very clear yet. As an attempt to find geophysical criteria to recognize the fault, geoelectrical resistivity survey was carried out in this study. With the Wenner configuration four resistivity soundings and twenty seven resistivity profilings were done. The electrode distance used was up to 50m. From the results of the resistivity soundings and boring data of earlier groundwater investigations the depth of alluvial and weathered zone was established to be at most 20m in the study area. In the resistivity profiling low resistivity anomaly zones are detected on every traverse, which are interpreted as caused by fractures, fault clays and mylonites in the fault zone. The width of the fault zone amounts to 0.3-1km. By correlating and connecting the negative anomaly zones from traverse to traverse one can determine the trend of th of the faultzone and therefore that of fault itself. The recognized fault trend in this way was $N15^{\circ}-20^{\circ}E$ and this coincides with the direction of the inferred fault line from earlier geological surface mapping. With the help of this characteristical negative anomaly the existance of another $N80^{\circ}W$ trending fault was estabished. This study has shown that geoelectrical resistivity survey can be applied successfully to the problem of tracing fault line insofar as a fault zone has been developed along fault line.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.585-590
• /
• 2002

Abrasive water-jet(AWJ) machining is a new cutting technology. The AWJ can cut various materials touch as metal, glass and stone. However, the AWJ machining makes troubles including kerf, rounding and side taper. In this study, we investigated the correlation between parameters of abrasive water-jet machining arid cutting characteristics. The machining parameter were the material thickness and the traverse speed. The experiment was conducted to cut the stainless steel(STS41) and the mild steel(SS41) specimens. The results of the experiment weirs presented as the relation between cutting conditions and trouble of a dimension error, a conner error, an uncut width and a kerf.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.984-987
• /
• 2002

Abrasive water-jet(AWJ) machining is a new cutting technology. The AWJ can cut various materials such as metal, glass and stone. However, the AWJ machining makes troubles including kerf, rounding and side taper. In this study, we investigated the correlation between parameters of abrasive water-jet machining and cutting characteristics. The machining parameters were the material thickness and the traverse speed. The experiment was conducted to cut the stainless steel(STS41) and the mild steel(SS41) specimens. The results of the experiment were presented as the relation between cutting conditions and troubles of a dimension error, a conner error, an uncut width and a kerf.