• Journal of Ocean Engineering and Technology
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• v.22 no.6
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• pp.83-87
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• 2008

Although a great deal of research has been carried out to solve the plate forming problem and to improve the effectiveness and productivity of the plate forming process, no practical way of automating the plate forming process has been proposed yet. Since characteristics of heating machines may vary, it is necessary to investigate the thermal deformation characteristics of the heating machine that will be used in the automation system its characteristics may be modified as new information about thermal deformation by heating becomes available. In this paper, experiments for line heating have been carried out to calculate the formula of predicting thermal deformation due to line heating with varying affecting parameters, and numerical study has been carried out to produce data beyond the range where a line heating test is impractical. Formulas of predicting transverse distortion and shrinkage have been proposed and derived, based on the present experimental and numerical works. This paper also illustrates how the formula has been modified as new experimental data are added.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1901-1907
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• 2018

This paper is a study for accurate iron loss calculation of a cylindrical linear machine for free piston engine. This study presents that it is possible to accurately predict power loss in ferromagnetic laminations under magnetic flux by specially considering the dependence of hysteresis, classical, and excess loss components on the magnetic induction derivative. Significant iron loss in the armature core will not only compromise the machine efficiency, but may also result in excessive heating, which could lead to irreversible deterioration in the machine performance. Thus, correct prediction of power losses under a distorted flux waveform is therefore an important prerequisite to machine design, particularly when dealing with large apparatus where stringent efficiency standards are required. Finally, it will be discussed about the iron loss in various materials of cylindrical linear electric machine by geometric and electrical parameters. It will give elaborate information about the perfect design and design rules of cylindrical linear machine and in parallel tools for the calculation, simulation and design will be available.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.9-15
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• 2012

Vibrational film has been more employed in ear-phones or small type of speakers along with a wide use of portable multi-media equipments such as MP3 and MP4. However, the current hand work production process of diaphragms is inefficient. In this study, a die-and-mold and a single production forming machine are developed, and they result in a multi-production forming machine. The multi-production forming machine consists primarily of a film feeding unit and an unwinding unit. A vacuum suction device provides the film feeding unit, while the unwinding unit is obtained using an appropriate damper. The advantage of the developed single production forming machine is shown according to a proper voice test.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.233-236
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• 2003

In this Paper, the temperature control error and cooling characteristics of inverter typ coolers are evaluated to predict application validity of coolers under heating pattern and amount The temperature control error of coolers small in 15~70% range of the max. cooling ability. At less than 15% of max. cooling ability has the inverter type cooler a basic temperature control error $\pm0.5^{\circ}C$ and acts as on/off type coolers. The inverter type cooler is unsuitable for precision temperature control under the complex heating pattern. But PID control of cooler including the heating system is an alternative for the case.

• Steel and Composite Structures
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• v.9 no.3
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• pp.209-221
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• 2009

Heating correction, through heating and flattening a structure with a pressing machine, is the in-situ method used to repair buckled steel structures. The primary purpose of this investigation is to develop an FEM model which can predict the mechanical response of heat-corrected plates accurately. Our model clarifies several unsolved problems. In previous research, the location of the imperfection was limited to the center of the specimen although the mechanical behavior is strongly affected by the location of the imperfection. Our research clarifies the relationship between the location of the imperfection and the mechanical behavior. In addition, we propose further reinforcement methods and validate their effectiveness. Our research concludes that the strength of a buckled specimen can be recovered by heating correction and the use of an adequate stiffener.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.530-535
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• 1999

In recently, annealing process of cold rolled sheet tend to change to continuous annealing process for improving quality, saving yield. In the meantime as demand for various kind and small lot of products has been increasing, batch annealing has been appreciated for its small restriction for the operation. So, we tested on the effect for the proper heating temperatures, heating time of cycle, cooling time and total cycle time in this annealing process of hi tensile strength steel for automobile. As a result of several investigation. we confirmed for the following characteristics; In this process, we knew that 68$0^{\circ}C$ is suitable for this heating temp. cycle heating time of 38 Hr, cooling time of 31 Hr and total cycle time of 70 Hr. Still more, we could know that it is proper for cold rolling before annealing to be managed by 7 pass because of the act on high pressure.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.139-147
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• 2005

The lubricant impregnated MC nylon has good frictional properties, but its mechanical strength is inferior to steel for the mechanical elements. For the tribological application Nylon as gears, sliding bearings, cam and etc, the steel shafts are fitted in pre-heated nylon cylinder by a process of interference expansion fit and bonded by induction heating method. The joint shear strength of the two materials was measured by a universal test machine. From the study, the adhesive shear strength between these two materials was affected by the factors of the interference between nylon and steel, the size of nylon cylinder, knurl of steel shaft and inducting heating conditions. The most effective jointing conditions were analyzed and decided for the practical application in the industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.659-663
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• 1998

Mook is a traditional Korean food made from the sediment of mungbean, cowpea, buckwheat or acorn. The air-dried sediment of cowpea(6~9%, dry basis) was heated to 80~95$^{\circ}C$ by continuous(method A) or instantaneous(method B) heating method and held at that temperature for 20min and then cooled at 15$^{\circ}C$ for 3hrs. The optimum deformation rate for the measurements of hardness and cohesiveness of cowpea mook by Instron Universal Testing Machine was 55~65% by method A and 60~70% by method B. The hardness of mook made by method A was the highest at heating temperature of 9$0^{\circ}C$, whereas that by method B was linearly decreased as the heating temperature increased at all concentrations. The mook made by method B had higher cohesiveness than that by method A. The ratio of cohesiveness to hardness was also higher in mook made by method B.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.68-72
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• 2003

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.11-17
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• 2002