• Journal of the korean Society of Automotive Engineers
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• v.14 no.6
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• pp.113-126
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• 1992

Recently the multi-kind, small-amount manufacturing system has been replacing the mass manufacturing system, and domestic machining inustry also is eager to absorb the new technology because of its high productivity and cost reduction. The optimization of the cutting condition has been a vital problem in the machining industry, which would help increase the productivity and raise the international competitiveness. It is intended in this study to investigate the machining costs per unit time which is essential to the analysis of the optimal cutting condition, to computer the cutting speed that lead to the minimum machining costs and the maximum production to suggest the cutting speed range that enables efficient speed cutting, and to review the machining economy in relation to cutting depth and feed. Also considered are the optimal cutting speed and prodution rated in rrelation with feed. It is found that the minimum-cost cutting speed increases and the efficient cutting speed range is reduced as machining cost per unit time increases since the cutting speed for maximum production remains almost constant. The machining cost is also lowered and the production rate increases as the feed increases, and the feed should be selected to satisfy the required surface roughness. The machining cost and production rate are hardly affected by the cutting depth if the cutting speed stays below 100m/min, however, they are subject to change at larger cutting depth and the high-efficient speed range also is restricted. It can be established an adaptive optimal cutting conditions can be established in workshop by the auto-selection progam for optimal operation. It is expected that this method for choosing the optimal cutting conditions might contribute to the improvement of the productivity and reduced the cost. It is highly recommended to prepare the optimal cutting conditionthus obtained for future use in the programing of G-function of CNC machines. If proper programs that automatically select the optimal cutting conditions should be developed, it would be helpful to the works being done in the machine shops and would result in noticeable production raise and cost reduction.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.79-83
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• 2000

A sliding mode fuzzy control (SMFC) with disturbance estimator is applied to design a controller for the third generation benchmark problem on an wind-excited building. A distinctive feature in vibration control of large civil infrastructure is the existence of large disturbances, such as wind, earthquake, and sea wave forces. Those disturbances govern the behavior of the structure, however, they cannot be precisely measured, especially for the case of wind-induced vibration control. Since the structural accelerations are measured only at a limited number of locations without the measurement of the wind forces, the structure of the conventional control may have the feed-back loop only. General structure of the SMFC is composed of a compensation part and a convergent part. The compensation part prevents the system diverge, and the convergent part makes the system converge to the sliding surface. The compensation part uses not only the structural response measurement but also the disturbance measurement, so the SMFC has a feed-back loop and a feed-forward loop. To realize the virtual feed-forward loop for the wind-induced vibration control, disturbance estimation filter is introduced. the structure of the filter is constructed based on an auto regressive model for the stochastic wind force. This filter estimates the wind force at each time instance based on the measured structural responses and the stochastic information of the wind force. For the verification of the proposed algorithm, a numerical simulation is carried out on the benchmark problem of a wind-excited building. The results indicate that the present control algorithm is very efficient for reducing the wind-induced vibration and that the performance indices improve as the filter for wind force estimation is employed.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1282-1287
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• 2011

The objective of this study was to assess the effect of xylanase on net energy for production, performance, nutrient digestion and gut microflora of broilers fed corn/soy-based diet. Eighty-four day-old male broiler chicks were allocated to two groups receiving two treatments, respectively. Each treatment had six replicate cages with seven broilers per cage. The diets were based on corn and soybean. The treatments were: i) basal diet reduced in apparent metabolizable energy (-0.63 MJ/kg compared to commercial diet specifications); ii) basal diet supplemented xylanase at 4,000 u/kg feed. The experiment used the auto-control, open circuit respiration calorimetry apparatus to examine the heat production and net energy for production. The results revealed that xylanase supplementation did not affect growth performance and diet AME value, but increased $NE_p$ value by 18.2% (p<0.05) and decreased daily heat production per $kg^{0.75}$ by 31.7% (p<0.05). There was no effect (p>0.05) of xylanase supplementation on the ileal digestibility of N and hemicelluloses, but the ileum digestibility of energy was increased by 2% by xylanase supplementation (p<0.05). Xylanase supplementation increased (p<0.05) the count of lactobacillus and bifidobacterial in the caecum.

• East Asian Journal of Business Economics (EAJBE)
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• v.1 no.1
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• pp.17-21
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• 2013

Purpose: Forecasting of petroleum consumption is useful in planning and management of petroleum production and control of air pollution. Research Design, Data and Methodology: ARMA models, sometimes called Box-Jenkins models after the iterative Box-Jenkins methodology usually used to estimate them, are typically applied to auto correlated time series data. Results: Petroleum consumption modeling plays a role key in big urban air pollution planning and management. In this study three models as, MLFF, MLFF with GARCH (1,1) and ARMA(1,1), have been investigated to model the petroleum consumption forecasts. Certain standard statistical parameters were used to evaluate the performance of the models developed in this study. Based upon the results obtained in this study and the consequent comparative analysis, it has been found that the MLFF with GARCH (1,1) have better forecasting results.. Conclusions: Survey of data reveals that deposit of government policies in recent yeas, petroleum consumption rises in Tehran and unfortunately more petroleum use causes to air pollution and bad environmental problems.

• Journal of Biosystems Engineering
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• v.5 no.2
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• pp.40-57
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• 1980

The aim of this study was to promote extensive use of strain gage for accurate measurement in the area of farm machinery research. The results are summarized as follows. 1. Although many strain gate transducers commercially available such as load-cells , accelerometers and pressure transducers have been used in the area of farm machinery research, many types of transducers had to be developed due to the inadaptability or high cost commercial transducers, in many instances. 2. A strain -gaged cantilever beam could be used as a good educational material to demonstrate the methods of Wheatstone bridge arrangement, calibration and theoreticval computation. A ring type load-cell and shaft torque transducer also could be used for the same purpose. 3. The torque and angular speed transducers for an auto-feed thresher and the displacement and pressure transducers for a rice whitener were made and gave satisfactory results. 4. Based on the above results, it is possible to develop simple and low-cost transducers to measure displacement, angular speed , torque and pressure of farm machine elements.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.660-663
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• 1996

There has been many activity to increase accuracy in machining center by reducing tracking error. The tracking error can cause bad effect in high speed rigid tapping in which syncronization servo motor with spindle is relatively important. To reduce tracking error, feed forward control has been used, but no method is provided knowing motor dynamics, force variation, etc. In this paper, we observe that, despite of tracking error of relevant axis, high speed tapping could be possible by reducing contour error of axis to be syncronized. We present the method to increase accuracy in high speed tapping to minimize contour error by automatically fitting gains of servo and spindle.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.363-366
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• 2003

We propose the system that automatically adjusts the white balance on display products to a standard value according to several nations. We replace manual or semi-auto method with fully automatic method using windows application program. And we use RS-232C serial interface to communicate PC with display products which we want to adjust white balance. The PC generates patterns for measuring color information and Color Analyzer measures color and brightness. This value is transmitted through RS-232C serial interface to PC. The PC's algorithm analyzes this information and then decides which RGB Gain value is best for optimal white balance. This RGB Gain value is transmitted through RS-232C serial interface to display products. The modified color value is measured again and feed back to PC. This sequence is repeated until optimum white balance is obtained.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.441-446
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• 2000

Although the net-shape molding of composites is generally recommended, molded composites frequently required cutting or grinding due to the dimensional inaccuracy for precision machine elements. During the composite machining operations such as cutting and grinding, the temperature at the grinding area may increase beyond the allowed limit due to the low thermal conductivity of composites, which might degrade the matrix of composite. Therefore, in this work, the temperature at the grinding point during surface grinding of carbon fiber epoxy composite was measured. The grinding temperature and surface roughness were also measured to investigate the surface grinding characteristics of the composited. The experiments were performed both under dry and wet grinding conditions with respect to cutting speed, feed speed, depth of cut and stacking angle. From the experimental investigation, the optimal conditions for the composite plain grinding were suggested.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.143-148
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• 1999

G code has to be made after changing the drawing information to DXF file, the converting file. When the information is changed, the converted file had the unnecessary time of rapid feed during working and the large DATA capacity. It need for arranging the information ordered irregularly. This CAM program based AutoCAD can be decreased uncomfortableness in contrast to use of each system. Also it can be increased productivity by arranging information. And it can be used easily for the beginner of the minor enterprises. its program can be decreased system error between others by using one system and increased work efficiency by using DCL.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.6
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• pp.548-555
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• 2014

As a considerable, experimental approach, an Auto-carriage type of $CO_2$ welding machine and a MIG(Metal Inert Gas) welding robot under inert gas atmosphere were utilized in order to realize Al 5083 welding applied to hull and relevant components of green Al leisure ships. This study aims at investigating the effect of welding conditions(current, voltage, welding speed, etc) on thermal deformation that occurs as welding operation and tensile characteristics after welding, by using Al 5083, non-ferrous material, applied to manufacturing of co-environmental Al leisure ships. With respect to welding condition to minimize the thermal deformation, 150A and 16V at the wire-feed rate of 6mm/sec were acquired in the process of welding Al 5083 through an auto carriage type of $CO_2$ welding feeder. As to tensile characteristics of Al 5083 welding through a MIG welding robot, most of tensile specimens showed the fracture behavior on HAZ(Heat Affected Zone) located at the area joined with weld metal, except for some cases. Especially, for the case of the Al specimen with 5mm thickness, 284.62MPa of tensile strength and 11.41% of elongation were obtained as an actual allowable tensile stress-strain value. Mostly, after acquiring the optimum welding condition, the relevant welding data and technical requirements might be provided for actual welding operation site and welding procedure specification(WPS).