Papers by Author: Dong Jo Yang

Abstract: In this investigation, we evaluated diagnoses of a defect concerning coating of land-base gas turbine using infrared thermography camera. In this camera method has a strong point which is able to save time and costs compared with former method. Because it can be long field acquire temperature distribution by using non-contact method. But it has a week point that method applies thermal load about inspection sample. Presently, Method used widely in detection of crack is ultrasonic inspection. But this method, There is problem in application in place that uneven surface. In order to check cracks on a blade coating of a gas turbine, a part with cracks in a waste blade disposed after having been used in the field was extracted to produce a sample. So we apply the method by a infrared thermography camera to the produced sample, the sample was heated by means of a halogen lamp. In this paper, we want to describe production of land-base turbine sample, a method of applying thermal load at produced sample, infrared thermography camera technique, an analysis technique of thermography, a defect analysis of coating of land-base gas turbine blades.

Abstract: After Industrial Revolution, energy has been recognized as an important factor which enhances the motive power for industry in the industrial society. However, recently the excessive consumption of energy pursuant to the rapid expansion of industry created serious problems of the exhaustion of fossil fuels as well as unusual change in the weather due to the mass discharge of carbon dioxide. We can say that after all proposals will boil down to the development of New & Renewable energy. The most suitable source of energy for this required change is solar energy. The advantages of solar energy are that it is renewable, infinite supplied and environmentally safe energy source, and the method of energy supply is in small scale and is decentralized. However, solar energy related products have the problems such as the limitation for installation, problems in maintenance and insufficient reliability, which have been the barrier to consumers to satisfy the purchase need for solar heat related products. In this research will perform thermodynamic analysis through the application of infrared ray thermal imaging camera and will discuss about the applicability of solar energy system and other fields as well.

Abstract: The main purpose of this investigation was to evaluate the performance of the solar hot water heater for dwellings in a long period of time. In order to evaluate the performance, there were 11 solar hot water heaters located in Gwangju Chosun University examined for their performance in 30 month period as a long term. The specific monitoring systems of each heater were constructed for the demonstrational research and the data base associated to each monitoring systems were assembled for an extensive analysis for variety of data obtained. The demonstrational experiments were conducted through following the routine procedures of 4 specific tests (the replicated drainage test, the daily drain test, the daily agitation test, the short-term test). The performance evaluation was based on the performances in insulating and solar collecting and the experimental routines and the performance experiments had incorporated the consumers’ use and need of the product. The ultimate goals of this investigation were to achieve consumers’ trust on the products and to promote the extensive distributions of the solar hot water heaters. The demonstrational research of this investigation was to evaluate the performance of the solar hot water heater for the residents for a long period of time. This research will be continued extensively.

Abstract: Tires are the only means for connecting a vehicle to the ground. The forces such as driving force, braking force, rotation force and the like occur on the contact surface between the tire and the ground and thus determine the motion of the vehicle. A general tire generates separation that continues to repeat tension and compression by the load of the vehicle. The separation raises the temperature of the tire, resulting in loosening between tire members and in the end damages the tire. Since a tire has a composite structure, which consists of rubber and reinforcements, many problems arise in the analysis of the tire. In this study, a tire of a composite structure was analyzed for heat transfer under the same condition as in the running state, so as to examine temperature distribution at tread. Theoretical results were verified using a thermal vision camera a non-contact non-destructive temperature measurement instrument.

Abstract: The purpose of this research is stability estimation of plant structure through classification and recognition about welding flaw in SWP(Spiral Welding Pipe). And, In this research, we used nondestructive test based on ultrasonic test as inspection method, and made up inspection robot in order to control of ultrasonic probe on the SWP surface, and programmed to signal processing code and pattern classifying code by user made programming code. Inspection robot is simply constructed as 2-axes because of welding bead with fixed pitch. So, inspection of welding part can be possible as composition of inspection part for tracking on welding line. For evaluation of flaw signal is reflected on welding flaw, user-made program codes are composed of signal processing and Bayesian classifier and perceptron neural network and back-propagation neural network. And then, we confirmed to superiority of neural network method compared with Bayesian classifier for classification and recognition rate. According to this result, we selected back-propagation neural network as classification and recognition method about the system of SWP stability Estimation[2]. Through this process, we proved efficiency on the system of SWP stability Estimation, and constructed on the base of the system of SWP stability Estimation for the application in industrial fields.