• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.23-27
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• 2009

The joint dispatch of regional electricity markets can improve the overall economic efficiency of interconnected markets by increasing the combined social welfare of the interconnected markets. This paper presents a new decentralized optimization technique based on Augmented Lagrangian Relaxation (ALR) to perform the joint dispatch of interconnected electricity markets. The Block Coordinate Descent (BCD) technique is applied to decompose the inseparable quadratic term of the augmented Lagrangian equation into individual market optimization problems. The Interior Point/Cutting Plane (IP/CP) method is used to update the Lagrangian multiplier in the decomposed market optimization problem. The numerical example is presented to validate the effectiveness of the proposed decentralized method.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.219-223
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• 2005

Nowadays laser cutting is the most promising method of cutting FPD(Flat Panel Display) glass in mass-production line. And this method can also be used to cut other brittle materials such as quartz, sapphire, ceramic and semiconductor The concept of this method is shown in picture 1. Laser beam heats glass up to strain point, not to melting point and cooling system chills glass to induce maximun thermal stress in glass surface and then the thermal stress generates micro thermal crack, in other words blind depth of crack, along laser beam and cooling line.

• The Mathematical Education
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• v.40 no.2
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• pp.335-343
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• 2001

Algebra is important part of mathematics education. Recent days, many mathematics educators emphasize on real world situation. Form real situation, pupils make sense of concepts, and mathematize it by reflective thinking. After that they formalize the concepts in abstract. For example, operation in numbers develops these course. Operation in natural number is an arithmetic, but operation on real number is algebra. Transition from arithmetic to algebra has the cutting point in representing the concepts to mathematics sign system. In this note, we see the cognitive tendency of 10th grade about operation of real number, their cutting point of transition from arithmetic to algebra, and show some methods of helping pupils.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.28-33
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• 2017

Recently, the operation of precision pocket machining has been studied for the high speed and accuracy in industry to increase production and quality. Moreover, the demand for products with complex 3D free-curved surface shapes has increasing rapidly in the development of computer systems, CNC machining, and CAM software in various manufacturing fields, especially in automotive engineering. The type of aluminum (Al6061) that is widely used in aerospace fields was used in this study, and end-mill down cutting was conducted in fillet cutting at a corner with end-mill tools for various process conditions. The experimental results may demonstrate that the end mill cutter with four blades is more advantageous than that of the two blades on shape forming in the same condition precise machining conditions. It was also found that cutting forces and tool deformation increased as the cutting speed increased. When the tool was located at $45^{\circ}$ (four locations), the corner was found to conduct the maximum cutting force rather than the start point of the workpiece. The experimental research is expected to increase efficiency when the economical precision machining methods are required for various cutting conditions in industry.

• Macromolecular Research
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• v.16 no.6
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• pp.492-502
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• 2008

This study examined the adsorption of a synthetic cutting fluid and cutting fluid effluent on chitosan and SDS-modified chitosan, Chitosan and SDS-modified chitosan were prepared in form of beads and fibers. A series of batch experiments were carried out as a function of the initial concentration of cutting fluid, contact time and pH of the fluid. The contact angle study suggested that the SDS-modified chitosan was more hydrophobic than chitosan. The Zeta potential study showed that chitosan, SDS-modified chitosan and synthetic cutting fluid had a point of zero charge (PZC) at pH 7.8, 9 and 3.2, respectively. SDS-modified chitosan has a greater adsorption capacity than chitosan. The experimental results show that adsorption capacity of the cutting fluid on 1.0 g of SDS-modified chitosan at pH 3 and for a contact time of 120 min was approximately 2,500 g/kg. The adsorption capacity of chitosan and SDS-modified chitosan increased with decreasing pH. The Langmuir, Freundlich, and Brunauer Emmett and Teller (BET) adsorption models were used to explain the adsorption isotherm. The Langmuir isotherm fitted well with the experimental data of chitosan while the BET isotherm fitted well with the SDS-modified chitosan data. Pseudo first- and second-order kinetic models and intraparticle diffusion model were used to examine the kinetic data. The experimental data was fitted well to a pseudo second-order kinetic model. The significant uptake of cutting fluid on chitosan and SDS-modified chitosan were demonstrated by FT-IR spectroscopy, SEM and heat of combustion.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.71-76
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• 2006

Treatment performance and microbial community structure were investigated in water-soluble cutting oil treatment process using biological activated carbon. DOC removal in BACI column at $15^{\circ}C$ was higher than at $25^{\circ}C$, but those of BAC3 column after 60days was high at$25^{\circ}C$. Also, quinone content of first-step reactors at $25^{\circ}C$ and $15^{\circ}C$ was much the same, but those of the third-step reactor at $25^{\circ}C$ was higher than at $15^{\circ}C$. The dominant type of two apparatus was ubquinone (UQ)-l 0 followed by UQ-8. Menaquinones were detected from $25^{\circ}C$ apparatus and effluent. This suggested that DOC removal at $25^{\circ}C$ was advanced degradation by attached microorganisms on the activated carbon surface. The DOC removal in long-term activated carbon apparatus increased with going in BAC3 column. This indicated the influent of POC was a result of DOC removal efficiency decrease. Integrated DOC removal from start point in experiment to break point and quinone content were showed a tendency of increasing with going last-step activated carbon apparatus. Therefore, the biological activated carbon apparatus used by this study was effective treatment process in contaminated groundwater by water-soluble cutting oil.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.39-47
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• 2004

In mold machining, there are many concave machining regions where chatter and tool deflection occur since MRR(material removal rate) increases as curvature increases even though cutting speed and depth of cut are constant. Boolean operation between stock and tool model is widely used to compute MRR in NC milling simulation. In finish cutting, the side step is reduced to about 0.3mm and tool path length is sometimes over loom, so Boolean operation takes long computation time and includes much error if the resolution of stock and tool model is larger than the side step. In this paper, curvature of CL (cutter location) surface and side step of tool path is used to compute the feedrate for constant MRR machining. The data structure of CL surface is Z-map generated from NC tool path. The algorithm to get local curvature from discrete data was developed and applied to compute local curvature of CL surface. The side step of tool path was computed by point density map which includes cutter location point density at each grid element. The feedrate computed from curvature and side step is inserted to new tool path to regulate MRR. The resultants were applied to feedrate optimization system which generates new tool path with feedrate from NC codes for finish cutting. The system was applied to the machining of speaker and cellular phone mold. The finishing time was reduced to 12.6%, tool wear was reduced from 2mm to 1.1mm and chatter marks and over cut on corner were reduced, compared to the machining by constant feedrate. The machining time was shorter to 17% and surface quality and tool was also better than the conventional federate regulation using curvature of the tool path.

• Journal of Powder Materials
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• v.11 no.5
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• pp.412-420
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• 2004

The purpose of the present study is to determine an optimum composition using cheaper powders keeping with high performance of hard rock cutting diamond saw blade. With 50Fe-20(Cu . Sn)-30Co specimen, a part of Co was replaced by Ni(5%, 10%, and 15%, respectively). These specimens were hot pressed and sintered for predetermined time at various temperature. Sintering is performed by two different methods of temperature controlled method and specimen dimension controlled method. In order to determine the property of the sintered diamond saw blade, 3 point bending tester, X-ray diffractometer, and SEM were used. As the Co in the bond alloy was replaced by Ni, the hardness of the specimen increased. Thus the 50Fe-20(CuㆍSn)-15Co-15Ni specimen showed the maximum hardness of 104(HRB). The results of 3 point bending test showed that flexure strength decreased along with increase in Ni content. This is attributed to the formation of intermetallic compound(Ni$_{x}$Sn) determined by X-ray diffraction. The fracture surface after 3 point bending test showed that diamond was fractured in the specimen containing 0%, 5%, and 10%Ni, and the fracture occurred at the interface between diamond and matrix in the specimen containing 15%Ni. The cutting ability test showed that the abrasive property was not changed in the specimen containing 0%, 5%, and 10%Ni. The optimum composition determined in this study is 50Fe-20(CuㆍSn)-20Co-10Ni.

• International Journal of CAD/CAM
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• v.11 no.1
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• pp.18-26
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• 2011

This paper proposes a new solid-shape modeling system based on a lusterware-image illustration. The proposed method reconstructs a three dimensional solid shape from a set of rough sketches that are typically drawn in the early stages of the design process. The sketches do not have to be strictly accurate, and this tolerance to the roughness of the input sketches is one of the major advantages of the proposed method. The proposed system creates an initial shape based on the silhouette of the input lusterware-images. Then the user can edit the initial shape with intuitive cutting and dishing-up operations, which are based on sketching user interface. To achieve the goal, the system retains the geometric model with two representations: a point-set data and a volume data. This dual data structure allows the program to create an initial shape from the input images with little computational cost, and the user can apply cutting and dishing-up operations without substantially increasing computational and memory requirements. In this research, we have tested the proposed system by reconstructing solid models of some mechanical parts from rough sketches. The experimental results indicate that the proposed method is useful for the prototyping of a solid shape.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.749-754
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• 1988

The texture measurement of Chinese cabbage leaves used for Kimchi preparation were con ducted by cutting and compression test and the results were compared to the sensory evaluation. The cutting force of cabbage leaf stalk increased by blanching or salting, and a maximum cutting force was attained by salting in 15% salt solution for 5 hours. The compression force and recovered height measured by compression test of Chinese cabbage leaf stalk decreased by blanching or salting, and the breaking point disappeared. Treatment with $CaCl_2$ solution increased the cutting force compression force and breaking strength of fresh leaves, but the effect disappeared by salting or blanching. Cutting strength could be used as a parameter indicating the hardness and chewiness of salted cabbage. Compression force and breaking strength could indicate the textural changes of blanched leaves, but were not useful for the measurement of hardness and chewiness of salted leave.