• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.3-6
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• 2002

This paper presents the cutting simulation system for prediction and regulation of cutting force in CNC machining. The cutting simulation system includes geometric model, cutting force model, and off-line fred rate scheduling model. ME Z-map(Moving Edge node Z-map) is constructed for cutting configuration calculation. The cutting force models using cutting-condition-independent coefficients are developed for flat-end milling and ball-end milling. The off-line feed rate scheduling model is derived from the developed cutting force model. The scheduled feed rates are automatically added to a given set of NC code, which regulates the maximum resultant cutting force to the reference force preset by an operator. The cutting simulation system can be used as an effective tool for improvement of productivity in CNC machining.

• Journal of Welding and Joining
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• 제30권4호
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• pp.44-48
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• 2012

H-beam used for stiffening the upper structure of ocean plant is cut in the various shapes. The cutting process of the H-beam is done manually and requires a long time and high cost. Therefore, automation of H-beam cutting is an important task. This research aims to develop a 3-D simulator to build the automatic H-beam cutting system and to determine the optimal cutting method. The automatic H-beam cutting system composes of 6 robots including 2 cutting robots hang to a crane and 1 conveyer. The appropriate system layout for covering the various sizes and types of H-beam was tested and determined using the simulator. The H-beam cutting system uses a hybrid type of plasma and gas cutting because of special cutting shapes of H-beam. The cutting area of each cutting method should be properly divided according to the size and shape of H-beam to shorten the total cutting time. Additionally the collision between a robot and a robot or a robot and H-beam should be avoided. The optimal cutting method for the shortest cutting time without the collision could be found for the various cutting conditions by use of the simulator. 2 simulation samples shows the availability of the simulator to find the optimal cutting method.

• 산업공학
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• 제9권1호
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• pp.1-10
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• 1996

In this study, expert system for the selection of the optimal cutting speed and feed rate was developed using NEXPERT system shell. The NC system has been usually used inefficiently because the input command, which contains cutting speed, feed-rate and the depth of cut, is fixed value which depends on principally operator's experience and machining handbooks providing a guideline for applicable ranges. On the other hand, the optimal cutting conditions vary with time, and depend on tool and machine characteristics, work materials, and cost factor and so on. In this study, if cutting factors, such as, cutting method, material type, cutting depth, and tool nose radius are specified, our expert system gets the information about the standard cutting speed form the cutting speed database, and provides optimum feed rate for these cutting conditions. This cutting speed database can be updated by inputting valid cutting speed which is obtained form the practices.

• Structural Engineering and Mechanics
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• 제65권2호
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• pp.203-211
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• 2018

This paper introduces the development process of NCC(New Concrete Cutting) system and analyzes first verification test. Based on the first verification test results, some problems of NCC system have been newly modified. We carry out the second verification test. We tried to verify cutting performance and dust control efficiency of NCC system through the cutting test of concrete bridge piers. In particular, this verification test strives to solve the problem of concrete dust, which is the biggest problem of dry cutting method. The remaining dust problems in cutting section tried to solve through this verification test. This verification test of the NCC system shows that the dust problem of dry cutting method is closely controlled and solved. In conclusion, the proposed NCC method is superior to the dry cutting method in all aspects, including cutting performance, dust vacuum efficiency and cooling effect. The proposed NCC system is believed to be able to provide eco-friendly cutting technology to various industries, such as the removal of the SOC structures and the dismantling of nuclear plants, which have recently become a hot issue in the field of concrete cutting.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1054-1058
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• 1995

There have been many research works for the indirect cutting force measurement in machining process, which deal with the case of one-axis cutting process. In multi-axis cutting process, the main difficulties to estimate the cutting forces occur when the feed direction is reversed. This paper presents the indirect cutting force measurement method in contour NC milling processes by using current signals of servo motors. An artificial neural network (ANN) system are suggested. An artificial neural network(ANN) system is also implemented with a training set of experimental cutting data to measure cutting force indirectly. The input variables of the ANN system are the motor currents and the feedrates of x and y-axis servo motors, and output variable is the cutting force of each axis. A series of experimental works on the circular interpolated contour milling process with the path of a complete circle has been performed. It is concluded that by comparing the ANN system with a dynamometer measuring cutting force directil, the ANN system has a good performance.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.370-375
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• 2004

This paper presents an accurate cutting simulation and feedrate scheduling system for CNC machining. This system is composed of a cutting simulation part and a feedrate scheduling part. The cutting simulation part computes the geometric informations and calculates the cutting forces in CNC machining. The cutting force model using cutting-condition-independent coefficients was introduced for flat end milling and ball end milling. The feedrate scheduling part divides original blocks of NC code into smaller ones with optimized feedrates to adjust the peak value of cutting forces to reference forces. Some machining examples show that the developed system can control the cutting force at desired levels.

• Journal of Biosystems Engineering
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• 제29권5호
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• pp.451-456
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• 2004

To establish a Altari radish pre-processing system far kimchi, the leaves and root tail of the Altari radish cutting de-vices were developed. The cutting resistances depend on the edge angles, oblique angles and cutting speeds were measured and analyzed. The experiments were performed to reveal the optimal conditions that showed the minimum cutting resistances acting on the materials. As the results, the optimum conditions that acting on the leaves were at edge angle $25^{\circ}$, oblique angle $40^{\circ}$ and cutting speed 0.5 m/s, and those acting on the root tails were at edge angle $20^{\circ}$, oblique angle $30^{\circ}$ and cutting speed 0.5 m/s, respectively. Considered a safety conception, the oblique angle of the leaves cutting device was adjusted as $20^{\circ}$, and then the cutting efficiencies of the both devices at these conditions were showed perfect performances.

• Journal of Welding and Joining
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• 제12권3호
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• pp.71-81
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• 1994

Laser cutting is experiencing a rising worldwide acceptance in the industry. Expert systems are necessary for the systematic arrangement and searching of experimental data existing in journal papers, job handbooks, etc.. This paper proposes an expert system for the selection of the appropriate laser cutting variables from the available database. Optimum cutting conditions according to the given cutting velocity were searched and qualitative comments which are difficult to be used as database variables were shown at each velocity using the binary and fuzzy inference. These comments could be informative to unskilled operators of the laser cutting process. Typical cutting conditions of the mild steel and stainless steel were included and the working range and quality variations were displayed graphically. The proposed algorithm was implemented in an IBM compatible personal computer as an expert system for CO$_{2}$ laser cutting to derive the optimum cutting conditions by using the turbo prolog.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.630-635
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• 2000

Previous research has not evaluated the effects of various rates and frequencies of manure application and frequencies of cutting on yield and stand persistence of cool-season grasses and alfalfa-grass mixtures. The primary objective of this study was to compare the effects of cutting management systems on herbage yield and stand persistence of orchardgrass (Dactylis glomerata L.) and an alfalfa (Medicago sativa L.)-orchardgrass mixture from various rates and frequencies of dairy slurry application. A randomized complete block design with treatments in a sub-subplot arrangement with four replicates was used. The main plot consisted of 2 cutting management systems (4 and 5 annual cuttings). The subplots were 9 fertility treatments: 7 slurry rate and frequency of application treatments, one inorganic fertilizer treatment, and an unfertilized control. The split-split-plots were the two forage species: orchardgrass and alfalfa-orchardgrass mixture. The study was initiated after 1st cutting in 1995. Cumulative yields of the 2nd and subsequent cuttings of both orchardgrass and alfalfa-orchardgrass in 1995 were higher for the 5-cutting system than the 4-cutting system. The 1995 growing season was abnormally dry. In 1996, an abnormally wet year, the reverse was true, total herbage yields being higher for the 4-cutting system than the 5-cutting system. Species response to fertility rate/frequency treatments was different in both years. Higher application rates early in the season and carryover of nutrients from late season applications the previous year appear to be responsible for the yield increases of those fertility treatments having significant yield differences between the cutting management systems. The stand ratings of orchardgrass were not affected by cutting management. In the spring of 1997, however, the stand ratings of alfalfa-orchardgrass in the 4-cutting management system were significantly greater than the 5-cutting management system. The very high manure application rate significantly reduced the stand ratings of alfalfa-orchardgrass in the 5-cutting system.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.1145-1151
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• 2022

A hybrid cutting using both plasma and end mill was developed for safe and efficient dismantling of nuclear facilities. In this cutting method, a moving arc plasma heats up the workpiece before milling. Thermally softened part of the workpiece is then removed quickly and deeply with an end mill. For the cutting experiments, a three-axis numerical control (NC) milling machine was combined with a commercialized arc plasma torch and used to cut 25 mm thick stainless steel plates. Experimental results revealed that pre-heating by arc plasmas can improve the cutting volume per unit time higher than 40% by reducing the cutting load and increasing the cuttable depth when using an end mill without cutting fluids. These advantages of a hybrid cutting process are expected to contribute to quick and safe segmentations of metal structures with radioactively contaminated inner surfaces.