• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.359-364
• /
• 1999

Due to rapid growth of die and mould industries, it is urgently required to maximize the productivity and the efficiency of machining. In recent years, owing to the development of new kinds of material, die and mould materials are much harder and it is more difficult to cut. In this study, the workpiece SKD11(HRC45) is cut with TiAlN coated tungsten-carbide cutting tools. To find the general characteristics of difficult-to-cut materials, orthogonal turning test is performed. Orthogonal cutting theory can be expanded to oblique cutting model. The oblique cutting process in the small cutting edge element has been analyzed as orthogonal cutting process in the plane containing the cutting velocity vector and chip-flow vector. Hence, with the orthogonal cutting data obtained from orthogonal turning test, the cutting forces can be analyzed through oblique cutting model. The simulation results have shown a fairy good agreement with the test results.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.6
• /
• pp.158-163
• /
• 2000

High speed machining of difficult-to-cut materials generates the concentrated thermal/frictional damage at the cutting edge of the tool and rapidly decreases the tool life. In this paper, the cutting environments, such as dry, fluid coolant, and compressed chilly air coolant, were investigated to improve the tool life. For this study, the compressed chilly air system was manufactured. The experiments were performed for various difficult-to-cut materials and various coated tools. The effectiveness of the developed methods on the basis of tool life was estimated. The results show that the cutting environment using compressed chilly air coolant provided better tool life than using the fluid coolant or using the dry.

• Journal of Sericultural and Entomological Science
• /
• v.13 no.2
• /
• pp.151-154
• /
• 1971

In the silkworm egg production, cutting of the cocoon's edge formed by silkworms forced to aid the emergence, and emergence is related to the amount of alkaloid liquid in the sucking stomach in certain varieties. In this study, there was no difference between cutting of portion and sex, and no significant between cutting of both sides and one side cocoons when comparing their emergence ratio. Expenditures and emergence ratio between both sides and one side cutting off must be studied in coming future.

• Communications of the Korean Mathematical Society
• /
• v.19 no.3
• /
• pp.577-584
• /
• 2004

In a 4-valent multi 3-gon graph, every cut-through curve forms a simple closed circuit. Hence it is a weak arrangement of simple curves that is defined by Branko Grunbaum. In this paper, we study the edge properties of the 4-valent multi 3-gon graphs from the point of view of arrangement, and we show that they are 3 colorable.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.23 no.60
• /
• pp.23-36
• /
• 2000

A probabilistic model of burr formation in face milling of gray cast iron is proposed. During a face milling operation, an irregular pattern of the edge profile consisting of burrs and edge breakouts is observed at the end of cut. Based on the metal cutting theory, we derive a probabilistic model. The operational bayesian modeling approach is adopted to include the relevant theory in the model.

• Journal of Korean Ophthalmic Optics Society
• /
• v.4 no.2
• /
• pp.57-63
• /
• 1999

The optical absorption and transmittance of cow' crystalline were measured by spectrophotometer in the 200~800nm wavelength regions. The optical absorptions of crystalline composed of a high absorption band in the UV-A, UV-B, and appeared the light transmittance edge in the 400nm wavelength region, and completely transmitted without the absorption in the high wavelength regions than 400nm. Also, the optical absorption and transmittance had no temperature dependence. The optical transmittance spectrum of crystalline concord with the thin film structure of $n_0/(0.5H)L(LH)^6(0.5H)/n_s$ and $n_0{\mid}(0.5LH0.5L)^kL/1.25{\mid}4.0$ of long-pass edge filter form. In the artificial crystalline and inter lens layout, long-pass edge filter layout can UV cut off.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.2
• /
• pp.11-23
• /
• 2011

In this paper, an accurate and fully automatic video object segmentation method is proposed for video conferencing systems in which the real-time performance is required. The proposed method consists of two steps: 1) accurate object extraction on the initial frame, 2) real-time object extraction from the next frame using the result of the first step. Object extraction on the initial frame starts with generating a cumulative edge map obtained from frame differences in the beginning. This is because we can estimate the initial shape of the foreground object from the cumulative motion. This estimated shape is used to assign the seeds for both object and background, which are needed for Graph-Cut segmentation. Once the foreground object is extracted by Graph-Cut segmentation, real-time object extraction is conducted using the extracted object and the double edge map obtained from the difference between two successive frames. Experimental results show that the proposed method is suitable for real-time processing even in VGA resolution videos contrary to previous methods, being a useful tool for immersive video conferencing systems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.10C
• /
• pp.1414-1424
• /
• 2004

In this paper, an algorithm using wavelet transform for detecting a cut that is a radical scene transition point, and fade and dissolve that are gradual scene transition points is proposed. The conventional methods using wavelet transform for this purpose is using features in both spatial and frequency domain. But in the proposed algorithm, the color space of an input image is converted to YUV and then luminance component Y is transformed in frequency domain using 2-level lifting. Then, the histogram of only low frequency subband that may contain some spatial domain features is compared with the previous one. Edges obtained from other higher bands can be divided into global, semi-global and local regions and the histogram of each edge region is compared. The experimental results show the performance improvement of about 17% in recall and 18% in precision and also show a good performance in fade and dissolve detection.

• The Korean Journal of Food And Nutrition
• /
• v.20 no.3
• /
• pp.295-303
• /
• 2007

As a result of life-style changes, consumer's concerns of food have shifted from calories and nutrition to health and convenience. Fresh-cut products are one such new direction for fruit and vegetable consumption. In this study, the vitamin C, mineral, and pesticide contents of various fresh-cut products were analyzed. According to sensory evaluations, the key reason for a lower than expected overall acceptability of many fresh-cut products is that they are likely to have browning and can easily lose their freshness. Also, the sensory evaluation showed that shriveling, the degree of browning, softening around the cut edge, and off-flavors were the primary factors affecting the quality of fresh-cut products. As a nutritional factor of quality, vitamin C content was not practical with regard to fresh-cut lettuce because the level was very low. For product safety, residual pesticides were detected in the fresh-cut products, but the results showed that all items were under permitted levels and considered safe. In evaluation of the microbial levels of the fresh-cut market products, the levels of viable cells, mold, yeast, coliform bacteria, and enterobacteriaceae were not significantly different based on the summer and winter seasons. The levels of S. aureus and Listeria spp. in the products were higher during the summer season than the winter.

• Journal of Welding and Joining
• /
• v.24 no.4
• /
• pp.32-38
• /
• 2006

The objective of present research works is to investigate the effects of process parameters, including the power of laser, cutting speed, material thickness, and the edge angle, on the melted area in the sharp edge of the cut material fur the case of cutting of a low carbon steel sheet using high-power CW Nd:YAG laser. In order to investigate the influence of edge angle and size of loop on the melted area in the sharp edge, angular cutting tests and loop cutting tests have been carried out. From the results of angular cutting tests, the relationship between the edge angle and the melted area has been obtained. The results of the experiments have been shown that the melted area is rapidly reduced from $120^{\circ}$ of the edge angle and the melted area is nearly zero at $150^{\circ}$ of the edge angle. Through the results of loop cutting experiments, the relationship between the cutting angle on the melted area in the edge according to the size of loop have been obtained. In addition, it has been shown that a proper size of loop is nearly 3 mm as the corner angle is greater than $90^{\circ}$ and 5 mm as the comer angle is less than $90^{\circ}$. The results of above experiments will be reflected on the knowledge base to generate optimal cutting path of the laser.