• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.12
• /
• pp.1035-1044
• /
• 2013

Because of the high specific stiffness and strength inherent in the sandwich structure composed of facesheet that resists in-plane loads and a core that resists out-of-plane loads, it is often used for large and light-weighted structures. However, inevitably the increased flexibility allows greater deformation-based disturbances in the structures. Thus, it is necessary to analyze the structural safety. To obtain more accurate analytical results, the input disturbances must more closely simulate real load conditions; to improve accuracy, non-linear elements such as gust effects were considered. In addition, the structural safety was analyzed for the iso-grid sandwich panel structure using fluid-structure interactions. For a more realistic simulation, flow velocity fields, which consider the effects of irregular gust fluctuation, were generated and the coupled field was analyzed by mapping the pressure and displacement.

• Journal of Labour Economics
• /
• v.39 no.3
• /
• pp.1-32
• /
• 2016

The purpose of this article is to examine the change of employment expectation using the wave 7-11 (2010-2014) of Korea Education and Employment Panel(KEEP). The three main variables are the reservation wage, which has been studied by labor economists for a long time, the convenient working environment factor, the desired job factor. Last two of which are extracted from the 15 survey questions about employment expectation using the factor analysis. Our estimates suggest that male have a higher reservation wage than female while female have a higher level of expectation overall. Women attach more importance to working environment especially. Also, university students have a higher reservation wage and set a higher value on the desired job than employees and job seekers.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.4
• /
• pp.365-373
• /
• 2011

Damage of reinforced concrete panel subjected to blast load using parallel and domain decomposition is analyzed. The numerical results are sensitive to the mesh size because blast waves are generated during the extremely short term. In order to investigate the effect of mesh size on the blast wave, the analysis results from various wave mesh size using AUTODYN, the explicit finite element analysis program, were compared with existing experimental results. The smaller mesh size was, the higher accuracy was. However, in this case, the analysis was inefficient. Therefore, in order to increase numerical efficiency, the parallel analysis using decomposed method based on Euler and Lagrangian description was performed. Finally, the decomposed method using both the structure domain based on Lagrange description and the blast wave domain based on Euler description was more efficient than the decomposed method using only the Lagrange mesh on structure domain.

• 한국체육학회지인문사회과학편
• /
• v.54 no.2
• /
• pp.285-297
• /
• 2015

This study aimed to research customer reward program factors of ski resorts in Korea through surveying the expert panel side and the customer side. This study conducted survey for 28 practicians that have been working for the department of customer reception of 6 different ski resorts all over the country and 7 faculties quited well-known in the academic circles. Delphi technique has been used to conduct survey customer reward program factors of the supplier side till the 3rd survey as the final. Based on this survey, an interview and a questionnaire survey have been used to conduct survey customer reward program factors that have been aware by the 50 customers, who have visited the ski resorts in 2014, and compared those two surveys above. In order to process the data, descriptive statistic analysis and Kendall W test have been utilized PASWWIN Ver. 18.0. The results were as follows: discount factor 8 articles, promotion factor 10 articles, package factor 5 articles, and convenience factor 6 articles have been produced as a good result.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.6 s.183
• /
• pp.136-142
• /
• 2006

Optimization of the aircraft panel assembly constructed by skin and stringers is investigated. For the design of panel assembly of the aircraft structure, it is necessary to determine the best shape of the stringer which accomplishes lowest weight under the condition of no instability. A panel assembly can fail in a variety of instability modes under compression. Overall modes of flexure or torsion can occur and these can interact in a combined flexural/torsion mode. Flexure and torsion can occur symmetrically or anti-symmetrically. Local instabilities can also occur. The local instabilities considered in this paper are buckling of the free and attached flanges, the stiffener web and the inter-rivet buckling. A program is developed to find out critical load for each instability mode at the specific stringer shape. Based on the developed program, optimization is performed to find optimum stringer shape. The developed instability analysis program is not adequate for sensitivity analysis, therefore RSM (Response Surface Method) is utilized instead to model weight and instability constraints. Since the problem has many local minimum, Genetic algorithm is utilized to find global optimum.

• Journal of Korean Institute of Fire Investigation
• /
• v.11 no.1
• /
• pp.83-88
• /
• 2008

The fire outbreaking origin of vehicle fire would be classified into two positions such as engine room and passenger room of vehicle. As a firewall is installed between engine room and passenger room, in case of engine fire, it could be assumed that it takes about 10 to 15 minutes for the fire to spread into passenger room There are two different vehicle engine layouts such as transversal and lateral layout, and the fire spreading process and resulting damage patterns on left and right side dash-panel are different depending on the engine layouts. In accordance, the first thing to do for correct and speedy finding of the fire origin place is considered to be an investigation into the dash-panel damage in case of engine room fire investigation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.1
• /
• pp.13-20
• /
• 2010

The development of the console for exterior advertizing LCD Panel(LCD Console) is the purpose of this study with regard to importance of display industry. In this study, the most important point is to develop the cooling system for LCD Console. It is developed by using systematic application techniques and statistical tests and analysis to integrate commercial components, cooling fan, heat sink, thermo electronic modules etc, of it. This study, at first, shows design/manufacturing process of the cooling system and the setting process of control factors to control through experimentation. Next, after constructing the complete console, 46 inch LCD Panel and the cooling system are built in, the performance test of it is shown through experimentation.

• Journal of the Korean Vacuum Society
• /
• v.11 no.2
• /
• pp.108-112
• /
• 2002

We investigated the secondary electron emission characteristics of MgO layer used as the protecting material in a.c. plasma display panel(a.c.-PDPs) using a pulsed ion beam technique, where the surface charging can be effectively suppressed during the measurement. The measurement of the secondary electron emission coefficients ($\gamma$) on the surface of $SiO_2$ was carried out and then, it was found that the yields were dependent on incident ion energies. In addition, it was clearly demonstrated that the sputtering on MgO surface leads to lower yields, which suggests that the surface plays a key role on the operating conditions, such as life time, fast response, and etc.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.154-155
• /
• 2016

Although there is an increase in demand for free-form buildings, there are several problems such as increased cost and duration and decreased constructability arising from difficult member production and installation. To solve these problems, a technology to produce free-form panels using CNC machine was developed. According to the technology, the information on free-form buildings designed is delivered to the CNC machine, a form is shaped using the delivered information and free-form concrete panels are produced using the form. The limited construction site, duration and project cost as well as interferences with other work types should be considered upon in-situ production of free-form concrete panels. Thus, the purpose of this study is to conduct a base study on in-situ production layout of free-form concrete panels by system dynamics. With this study, we will discover the causal relationship of influence factors on in-situ production of free-form concrete panels, and improved productivity is expected through the production layout.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.1
• /
• pp.13-20
• /
• 2021

In this paper, a new algorithm is proposed to estimate the damage size by combining the reflected area with the reflected position and extracting contours in proportion to the maximum value of pixels from the visible image. The cumulative summation feature vector algorithm is used to obtain the area of the reflected signal. To get the position of the reflected signal, the signal correlation algorithm is used to decompose the reflected signal from the damage. The proposed algorithm is tested and validated for composite panels. Repetitive experiments are performed and it is confirm that the proposed algorithm is reproducible. Further, it is verified that the damage size can be estimated appropriately by the proposed algorithm.