In this paper, based on the existing research, we define the parameters for the number of ignition devices to be applied to the pyrovalve, the operation and airtightness according to the temperature, the material of the nipple and the thickness of the fractured part, and ANSYS Ver. 19.2 was used to analyze the FEA model, and a comparative analysis was conducted through structure analysis according to the piston shape of the pyrovalve. In addition, an experimental study was conducted by manufacturing a prototype according to the design variables. As a result, high-strength pyrovalves can stably supply working fluids such as fuel and oxidizer for space launch vehicle propulsion engines, as well as precisely control flow path switching was confirmed.

In turbopump type liquid rocket engines, ignition and starting are known to be the most unstable and risky section among all operating sections of the projectile. The operation of the liquid rocket engine is the process of ignition and combustion of the main combustor after the turbo pump is driven into a stable section due to the turbine driving of the turbo pump and the ignition and combustion of the gas generator by the pyro starter. In this process, the driving of related components directly influences each other, so each component must be operated with sufficient reliability. In particular, if the igniter does not supply sufficient ignition energy at a predetermined time, an explosion may occur due to stagnation of the fuel/oxidant mixture, so reliability is more important. In this study, the fracture analysis of the gas generator igniter rupture disk according to the shape was performed using computational analysis. As a result, comparative analysis was performed to obtain the optimal dimensions according to each variable condition.

Interest rate spreads indicate the conditions of the economy and serve as an indicator of the recession. The purpose of this study is to predict Korea's interest rate spreads using US data with long-term continuity. To this end, 27 US economic data were used, and the entire data was reduced to 5 dimensions through principal component analysis to build a dataset necessary for prediction. In the prediction model of this study, three RNN models (BasicRNN, LSTM, and GRU) predict the US interest rate spread and use the predicted results in the SVR ensemble model to predict the Korean interest rate spread. The SVR ensemble model predicted Korea's interest rate spread as RMSE 0.0658, which showed more accurate predictive power than the general ensemble model predicted as RMSE 0.0905, and showed excellent performance in terms of tendency to respond to fluctuations. In addition, improved prediction performance was confirmed through period division according to policy changes. This study presented a new way to predict interest rates and yielded better results. We predict that if you use refined data that represents the global economic situation through follow-up studies, you will be able to show higher interest rate predictions and predict economic conditions in Korea as well as other countries.

In this paper, optical infrared thermography simulation using thermal wave imaging technique is performed to analyze the thermal characteristics of delamination defects. In this study, lock-in thermography(LIT) and pulsed thermography(PT) simulation was performed to analyze the samples of european traditional tiles with delamination defects, and the analytical modeler was developed through the ANSYS 19.2 transient thermal analysis tool. Applied sinusoidal heating with modulation frequency according to pulse heating and phase locking technique. The thermal response of the sample surface by heating was recorded and then data analysis was performed. The temperature gradient characteristics of each technique were compared, and phase angle was calculated for the LIT to analyze the parameters for the experiment setting. The simulation model was developed as a useful data for practical optical infrared thermography tests.

The 3-way valve have been used as a valve for opening and closing the valve by the flow control in the pressure system of the cryogenic and high pressure environment. In this paper, numerical analysis and experimental study on fracture nipple of 3-way ultra high pressure valve applied to space launch vehicle was carried out. We have developed a 3-way valve numerical simulation modeler of cryogenic environment using commercial software ANSYS 18.2. As results of numerical analysis, optimum nipple condition was derived. In addition, a 3-way valve prototype was fabricated and the fracture test was performed and compared with the numerical analysis results.

Nondestructive testing is a method of inspecting particular target objects without destructing them in industrial sites. Infrared thermal imaging is one of the nondestructive testing techniques. Among them, lock-in infrared thermography technique is a technique to detect a defect by generating a temperature difference of an object using periodic heat waves. This paper deals with the development of lock-in infrared thermography technique by using numerical analysis model for SM45C metal specimens. As a result, the appropriate frequency was determined for defect detection in SM45C metal specimen by using the established thermal behavior mechanism by periodic heat wave.

Infrared thermography provides the colorful images of concerning area where local changes of surface temperature occurs and can be used to measure the fine temperature of human body. Unlike the radiography technique, it is determined by the presence or absence of existing anatomical principles capable of quantitative evaluation and visible to the physiological and functional state of the human body. In this paper, it was studied the characteristics of dynamic motion conditions in the hands due to physiological changes of temperature distribution. The results showed that the difference between the change in temperature characteristics for the left and right hand.

Dental brackets are widely used by the orthodontists to correct the misalignment of teeth in the mouth over a long period of time. In this study, finite element analysis of orthodontic bracket has been carried out for the observation of the stress distribution and deformation pattern in the different materials bracket (Stainless Steel, Ceramic, Titanium, Polycarbonate and Nitinol) when subjected to arch wire torsion and tipping force. The simulation results were further optimized with respect to bracket attachment surface. It was found that it is possible to know the change in result is correlated with the attachment surface of the stress and deformation due to change in diameter. The results confirmed that the finite element method has proved to be successful for proper design analysis for future development of the teeth bracket.

Orthodontic is important to apply the optimal orthodontic force. The orthodontic bracket is deformed and the stress caused by tension and torsion of the wire. In this study, using the ANSYS the material that is currently widely used in orthodontic bracket material of stainless steel, ceramic, titanium, polycarbonate, by applying the nitinol analyzed the strain and the stress distribution on the bracket side. Simulation results on the stress distribution and deformation, and it was found a difference of each material.

Numerous experiments have demonstrated that infrared thermographic methods are effective for detection of subsurface defects in the materials. The response of the material to the thermal stimulus is dependent on the existence of subsurface defects and their features. In order to obtain the information about defects, the material’s response to the thermal stimulus is studied. In this study, image processing was applied to infrared thermography images to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, thermal images were often not appropriate. Thus, four point method was used for processing of every pixel of thermal images using MATLAB program for quantitative evaluation of defect detection and characterization which increased the infrared non-destructive testing capabilities since subtle defects signature became apparent..

To minimize damage from disasters, various aspects of prevention, preparation, and response, etc. are being managed. A system that can share the identical disaster information based on prompt disaster management and prediction must be developed and constructed for integrated disaster management.