• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.10
• /
• pp.1935-1940
• /
• 2011

The control logic of steam temperature was redesigned, tested and applied to the power plant after its steam temperature equipments had been revised. This power plant use the ancillary gas gotten in the process of making iron in the steel mill. The boiler of power plant has the superheater and reheater to make the superheated steam. The superheater and reheater have the spray valve to control their temperature. The reheater has the gas bypass damper additionally in this plant. The control logics were redesigned in cascade forms and the initial parameters of control logics were calculated from the several step tests. The final parameters could be obtained through the several repeated tests and the feedforward functions were added by temperature deviation and air flow. The power plant is being commercially-operated normally by improved control logics and It is expected that this improved controls help the efficiency improvement and safe operation of plant.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.2
• /
• pp.129-134
• /
• 2017

The process of producing a fish trap frame is very complicated and manual, so it is expensive, the quality of the product is unstable, the quality is not guaranteed, the durability is weak, and it cannot be used for a long time. Therefore, we made a fish trap frame-making machine to reduce the manpower and costs and to make robust products. This machine cuts the wire of mild steel to a certain size and then makes the connecting parts into a trapezoid shape by spot welding. In this study, the weld point shear strength between manual and automatic operation was compared and analyzed.

• Journal of Engineering Education Research
• /
• v.15 no.5
• /
• pp.36-41
• /
• 2012

Student members from The University of Tokushima worked voluntarily at the science school for elementary school children and high school students under the support of Japan Science and Technology Agency. The teaching classes for the science school were held in 2010 as follows: (1) Science handicraft class for children on "Wonder in light, sound, temperature and force", (2) Family Science School for children and parents on "Measurement of length, temperature, weight and energy", (3) "Tatara steel making" for high school students, (4) "Wave motion in strings" for high school students. This paper describes how the students prepared the teaching materials and what they obtained from the teaching activities.

• Smart Structures and Systems
• /
• v.4 no.3
• /
• pp.291-304
• /
• 2008

Piezoelectric materials have been widely used in ultrasonic nondestructive testing (NDT). PZT ceramics can be used to receive and generate surface acoustic waves. It is a common application to attach PZT transducers to the surface of structures for detecting cracks in nondestructive testing. However, not until recently have piezoelectric polymers attracted more and more attention to be the material for interdigitated (IDT) surface and guided-wave transducers. In this paper, an interdigitated gold-on-polyvinylidene fluoride (PVDF) transducer for actuating and sensing Lamb waves has been introduced. A specific etching technology is employed for making the surface electrodes into a certain finger pattern, the spacings of which yield different single mode responses of Lamb waves. Experiments have been performed on steel and carbon fiber composite plates. Results from PVDF IDT sensors have been compared with those from PZT transducers for verification.

• 한국연소학회:학술대회논문집
• /
• 2001.11a
• /
• pp.161-168
• /
• 2001

Sintering bed of iron ore in the steel making process is one of typical applications of solid fuel bed, which has relatively uniform progress of fuel and simple processes of combustion. The sintering bed was modelled as an unsteady one-dimensional progress of fuel layer containing the two phases of solid and gas. Cokes added to the raw mix of which the amount is about 3.5% of the total weight was assumed to form a single particle with other components. In the early predition results presented in this paper, the flame propagation within the bed was not sustained after the top surface of the bed was ignited with hot gas. It suggests that the model should be extended to consider the multiple solid phase, which can treat the ore particles and the coke particles separately.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.11a
• /
• pp.633-636
• /
• 2006

In order to determine new settings of key process variables optimally, a new rule induction method through a historical data is proposed without using an explicit functional model between process and quality variables. First, a partial least square is used to reduce the dimensionality of the process variables. Then new process settings that yield the best quality variable are identified by sequentially partitioning the reduced latent variable space using a patient rule induction method. The proposed method is illustrated with a case study obtained from steel-making processes. We also show, through simulation, that the proposed method gives more stable results than estimating an explicit function even when the form of the function is known in advance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.57-60
• /
• 2009

Exothermic and ignition characteristic of igniter is very important factor in engine performance. Since the igniter performance is effected by Hydrogen Peroxide decomposition rate, we have to test the preliminary catalyst performance test. In this report, after making igniter using hydrogen peroxide/kerosene, a thermal characteristic were examined by comparing hydrogen peroxide mass and catalyst mass. And then we study ignition characteristic of the affects of O/F ratio using the previous data.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.10a
• /
• pp.262-269
• /
• 2004

Ship structures are basically an assembly of plate elements and the load-carrying capacity or the ultimate strength is one of the most important criteria for safety assessment and economic design. Also, Structural elements making up ship plated structures do not work separately, resulting in high degree of redundancy and complexity, in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy needed and the degree of complexity of the analysis to be used. On this study, to investigate effect of analysis range, the finite element method are used and their results are compared varying the analysis ranges. The model has been selected from bottom panels of large merchant ship structures. For FEA, three types of structural modeling are adopted in terms of the extent of the analysis. The purpose of the present study is to numerically calculate the characteristics of ultimate strength behavior according to the analysis ranges of stiffened panels subject to uniaxial compressive loads.

• Steel and Composite Structures
• /
• v.6 no.2
• /
• pp.87-101
• /
• 2006

The deformation and dynamic behavior mechanism of submerged shell-like lattice structures with membranes are in principle of a non-conservative nature as circulatory system under hydrostatic pressure and disturbance forces of various types, existing in a marine environment. This paper deals with a characteristic analysis on quasi-periodic and chaotic behavior of a circular arch under follower forces with small disturbances. The stability region chart of the disturbed equilibrium in an excitation field was calculated numerically. Then, the periodic and chaotic behaviors of a circular arch were investigated by executing the time histories of motion, power spectrum, phase plane portraits and the Poincare section. According to the results of these studies, the state of a dynamic aspect scenario of a circular arch could be shifted from one of quasi-oscillatory motion to one of chaotic motion. Moreover, the correlation dimension of fractal dynamics was calculated corresponding to stochastic behaviors of a circular arch. This research indicates the possibility of making use of the correlation dimension as a stability index.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.347-348
• /
• 2009

This study is epoch-making for CO$_2$ reduction. Lay out for this, I used the malting furnace slag which produced in the steel palnt It confirmed the physical properties of the paste that it mixes the gypsum and the clinker.