• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.124-130
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• 2007

The emphasis of this paper is to find out the changes in length of nose in line with speed improvement and changes of the tendency in the shape of the nose in line with time series based on the Shinkansen vehicle. The length of the nose on the lines of high speed tends to get longer, however there is no proportion between the speed and the nose according to optimal design that was designed to reduce micro-pressure wave and air resistance. The Shinkansen vehicles, according to the shape, can be classified in to an Advanced Paraboloid shape, a Sharp-nosed shape, a Flat-nosed shape and an Organic Double-edged shape and is gradually changing in the trend of diversity and distinction. Hereafter, the design of the nose will be developed better into the design that will comprehend identity of manufacturer, region and culture on the basis of optimized aerodynamic shape.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.86-92
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• 2021

As interest and demand for high value-added industries, including the global automobile and aerospace industries, have increased recently, demand for line centers with excellent performance that can respond to the production system for producing high value-added products is also rapidly increasing. A line center improves productivity based on the installed area using a multi-spindle compared to a conventional machining center. However, as the number of spindles increases, the weight increases and results in structural problems owing to the heat and vibration generated by each spindle. Therefore, it is necessary to improve machining precision through the structural improvement of the line center. This study presents research on the stabilization design of the line center through structural stability analysis through structural analysis to develop a compact multi-axis line center. An optimization model of the line center has been proposed to improve the processing precision and increase the rigidity by performing weight reduction based on the structural analysis results.

• Journal of the Korean Chemical Society
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• v.21 no.5
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• pp.362-371
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• 1977

In this paper application of the projection operator technique to the study of NMR absorption line shape and free induction decay curve is explored. It is found that the projection operator technique can provide a convenient means for deriving a set of hierarchy equations which may serve as a good starting point for theoretical calculation of the absorption line and free induction decay function by successive approximation or by an appropriate decoupling approximation. A brief review of linear response theory of NMR line shape and the relation between the absorption line shape and free induction decay function are also described.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.156-162
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• 2000

Model experiments for a purse seine were carried out in order to measure the geometry of net shape and to estimate an enclosed volume by using 1177 scale model purse seine of 12.62m float line from an offshore mackerel purse seine. A model purse seine was set from a net box of shooting equipments and then pursing and hauling net by hauling equipment. The 3- D geometry shape of the purse seine net during hauling operation was measured by video image processing and tension of purse line by load cell. The 3-D geometry of the model purse seine during hauling operation could be represented with variables such as a ratio of shooting diameter or maximum net depth and a ratio of hauling operation time. Horizontal shapes of float line and lead line were varied from a circle after shooting to an ellipse with pursing and hauling. Projected lateral shape of purse line was observed and formulated as a shape of a water drop. The cross sectional shapes of curved net from two directions were varied such as sine function or polynomial curves. Therefore, enclosed volume of a purse seine in relation to fish school behaviour can be approximated using two main variables from relevant equations.

• Transactions on Electrical and Electronic Materials
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• v.17 no.6
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• pp.363-368
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• 2016

Rectangular shape detection plays an important role in many image recognition systems. However, it requires continued research for its improved performance. In this study, we propose a strong rectangular shape detection algorithm, which combines the canny edge and line detection algorithms based on the perpendicularity and parallelism of a rectangle. First, we use the canny edge detection algorithm in order to obtain an image edge map. We then find the edge of the contour by using the connected component and find each edge contour from the edge map by using a DP (douglas-peucker) algorithm, and convert the contour into a polyline segment by using a DP algorithm. Each of the segments is compared with each other to calculate parallelism, whether or not the segment intersects the perpendicularity intersecting corner necessary to detect the rectangular shape. Using the perpendicularity and the parallelism, the four best line segments are selected and whether a determined the rectangular shape about the combination. According to the result of the experiment, the proposed rectangular shape detection algorithm strongly showed the size, location, direction, and color of the various objects. In addition, the proposed algorithm is applied to the license plate detecting and it wants to show the strength of the results.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.10
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• pp.1443-1454
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• 2002

The purposes of this study were to classify body type of adult males into several kind of shape and to provide the characteristics of size of each group which has same shape. As the sample, subjects were 1290 males of 20 to 54 year-old. The procedure and results were follows; 1. As the result of the previous reserch, the front line of body was classified in X, H, Y and A types. 2. The principal component analysis was used to obtain the shape factor of the side line of the trunk. 9 factors in the side were extracted. As the result of the cluster analysis of factor scores, the side line of body was classified in 5 types. It was named X, A, Y and H type in the front and S, D1, d, I and D2 type in the side. 3. In order to consider the shape of body as a whole, the body shape of the front and side were compounded. The whole body shapes of adult male were very various, and 6 body shapes, XS, YS, Yd, YI, AD2 and HD1 were selected as the basic types. In each type of body, several groups were classified by size factor, height and chest girth and master size was selected considering appearance frequency.

• Transactions of Materials Processing
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• v.27 no.2
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• pp.87-92
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• 2018

Auto industries have tried to employ lightweight alloys to improve the fuel efficiency of manufactured vehicles, as the environmental concern becomes an important issue. Even though the aluminum alloy is one of the most appropriate lightweight alloys for auto parts, the low formability of an aluminum alloy has been an obstacle to its application. In order to resolve the low formability problem, a recent study (Lee et al., 2017 [1]) showed that the infrared (IR) local heat treatment can improve the formability with a reduction of heating energy. However, the aforementioned study was limited to only a linear line heating. Since many of the available auto parts as applicable to vehicle manufacturing have a curved line shape, the heating experiments for a curved line should be studied. The possibility of building IR lamps having complex shapes is an advantage of the IR lamp, since it can control the heating shape. This work conducted the IR local heat treatment for the curved line. The experimental results show that the IR local heat treatment can improve the formability of the aluminum alloy for curved line. Additionally, it is shown that the IR local heat treatment also reduces the heating energy when it is compared with the furnace heating which heats a blank as a whole. A numerical simulation with a stress-based forming limit diagram also supports the experimental results.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.525-532
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• 2005

Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using response surface method and three-dimensional Navier-Stokes analysis. Three design variables of blade sweep. lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor. the adiabatic efficiency is increased by reducing the tub comer and tip losses. Separation line due to the interference between a passage shock and surface boundary layer on the blade suction surface is moved downstream for the optimized blade compared to the reference one.

• Transactions of Materials Processing
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• v.24 no.1
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• pp.28-36
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• 2015

After a short review of the iterative optimal blank method, a new method of measuring the shape error for stamped parts with 3D contour lines, which is an essential component of the optimal blank design, is proposed. When the contour line of the target shape does not exist in a plane, but exists in 3D space, especially when the shape of the target contour line is very complicated as in the real automotive parts, then the measurement of the shape error is critical. In the current study, a method of shape error measurement based on the minimum distance is suggested as an evolution of the radius vector method. With the proposed method, the optimal blank shapes of real automotive parts were found and compared to the results of the radius vector method. From the current investigation the new method is found to resolve the issues with the radius vector method.

• Journal of computational fluids engineering
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• v.13 no.1
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• pp.1-6
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• 2008

Direct Write Technologies are being utilized in various industrial fields such as antennas, engineered structures, sensors and tissue engineering. With Direct Write Technologies, producing features have the mesoscale range, from 1 to 100 microns. One form of the Direct Write Technologies is based on aerosol dynamics. The shape of deposited aerosols determine the form of products in the Direct Write Technology based on aerosol dynamics. To predict shape of deposited aerosol, a prediction model is created. In this study, we estimated Line-Width and Line-Thickness from the prediction model. Results of prediction model is valid from comparison with experimental results.