• Journal of Ocean Engineering and Technology
• /
• v.21 no.5
• /
• pp.55-60
• /
• 2007

Bellows are mechanical components which prevent the damage of system by absorption of the vibration and the displacement of axle and radial direction. Thermal piping system is expanded by the fluid of the high temperature from the heat engine inside. At this time, bellows prevent the damage of the piping due to the thermal expansion. Recently, design of bellows is required to fit some other operational environments which are not suggested in the E.J.M.A code book. And it is difficult to produce and to maintain bellows of high temperature and high pressure bemuse of its complicated shape and this causes the manufacturing cost to rise. The objective of this study is to determine optimum shape of bellows which can endure in the high temperature and high pressure. The maximum stress has an effect on the fatigue life of bellows, therefore it needs to be minimized. This study attempts to find a shape which minimizes the stress occurring in the bellows by the design of experiment. The model used in this study is not presented in the E.J.M.A code book, therefore, from the result of design of experiment we find the factors which give effects on the characteristic value and we presents the recession model using the RSM, which can predict the characteristic values depending on the change of factor values.

• The Research Journal of the Costume Culture
• /
• v.15 no.3 s.68
• /
• pp.420-430
• /
• 2007

Noting that there is an increasing trend of the so-called 'neo-single life style' among women these days, this research aims to make a product development for these neo-single women in this era of families of a single member by analyzing their concepts and characteristics. We payed a particular attention to the data from such sources as newspapers, magazines or the articles in the Internet. The essence of our research lies in the analysis of target market, in the suggestions in the brand planning and product development and in the designs of fashion and interior products for them. The result of this research is as follows. First, it turns out that these neo-single women enjoy a kind of multi-mixing code lifestyle rather than showing a preference for a particular brand. For this reason, we have decided to pursue a multi-concept brand fonn as a right direction for brand planning for them. Second, as for a philosophy behind the brands, we suggest a concept of 'small utopia' for neo-single women and express such as new aristocracy, happiness and pleasure. Third, we adopt 'YOU' as the name of the brand as it reflects their various life styles and characteristics. Fourth, as for the product development of F/W in 2007, we have decided on 'Minimal Natural' as it mixes up the concepts of the controlled beauty of sophistication and multi-functional elements and 'Modern Primitive' as it expresses the ethnic elements on modern images having craft factors and modern images. We have performed concrete tasks in creating images, coloring, making fabrics for each theme. Fifth, we have chosen and suggested other products that are suitable for these neo-single women who seek for multi-functional but simple kinds after surveying a wide range of products in magazines or in the Internet.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.8
• /
• pp.747-757
• /
• 2010

The ice accreted on the airfoil is one of the critical drivers that causes the degradation of aerodynamic performance as well as aircraft accidents. Hence, an efficient numerical code to predict the accreted ice shape is crucial for the successful design of de-icing and anti-icing devices. To this end, a numerical code has been developed for the prediction of glaze ice accretion shape on 2D airfoil. Constant Source-Doublet method is used for the purpose of computational efficiency and heat transfer in the icing process is accounted for by Messinger model. The computational results are thoroughly compared against available experiments and other computation codes such as LEWICE and TRAJICE. The direction and thickness of ice horn are shown to yield similar results compared to the experiments and other codes. In addition, the effects of various parameters - temperature, free-stream velocity, liquid water contents, and droplet diameter - on the ice shape are systematically analyzed through parametric studies.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.4
• /
• pp.40-47
• /
• 2010

This study deals with the investigation about the effect of the pilot and split injection strategies on the spray-atomization characteristics of biodiesel fuel derived from a soybean oil. Experimental results were compared with the calculation results obtained from the numerical analysis. Fuel properties of biodiesel according to the variation of the fuel temperature were inserted to the fuel library in the KIVA code. The amount of fuel injection is divided into equal mass for each split and main injection. In this work, the pilot injection strategy can be achieved by the amount of fuel injection shortly before the start of the main injection. A spray tip penetration, radial distance and spray area were measured for the analysis of macroscopic spray characteristics. In addition, the local and overall droplet size distribution were calculated by using KIVA-3V code to study the effect of split and pilot injection on the atomization performance under high ambient pressure. From these studies, the experimental results showed the multiple injection induced the decrease of the spray tip penetration due to the reduction and division of the spray momentum compared to single injection. In the atomization performance, the droplet size increased in the case of the multiple injection a little. Moreover, the SMD slightly increased as the fuel droplets goes through the axial direction. The spray behavior of numerical results were well predicted the experimental multiple spray characteristics of biodiesel fuel.

• International Journal of High-Rise Buildings
• /
• v.2 no.3
• /
• pp.257-269
• /
• 2013

This study presents the development of an advanced multiple database-enabled design module for high-rise buildings (DEDM-HR), which seamlessly pools databases of multiple high frequency base balance measurements from geographically dispersed locations and merges them together to expand the number of available building configurations for the preliminary design. This feature offers a new direction for the research and professional communities that can be utilized to efficiently pool multiple databases therefore expanding the capability of an individual database and improving the reliability of design estimates. This is demonstrated, in this study, by the unprecedented fusion of two major established databases, which facilitates interoperability. The DEDM-HR employs a cyberbased on-line framework designed with user-friendly/intuitive web interfaces for the convenient estimation of wind-induced responses in the alongwind, acrosswind and torsional directions with minimal user input. In addition, the DEDM-HR embeds a novel feature that allows the use of wind characteristics defined in a code/standard to be used in conjunction with the database. This supplements the provisions of a specific code/standard as in many cases guidance on the acrosswind and torsional response estimates is lacking. Through an example, results from several international codes and standards and the DEDM-HR with the embedded features are compared. This provision enhances the scope of the DEDM-HR in providing an alternative design tool with nested general provisions of various international codes and standards.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.18 no.6
• /
• pp.797-807
• /
• 2008

This paper proposes a new algorithm of extracting forward vehicle areas using the acquired lanes and road area information on road images with complex background to improve the efficiency of the vehicle detection. In the first stage, lanes are detected by taking into account the connectivity among the edges which are determined from a method of chain code. Once the lanes proceeding to the same direction with the running vehicle are detected, neighborhood roadways are found from the width and vanishing point of the acquired roadway of the running vehicle. And finally, vehicle areas, where forward vehicles are located on the road area including the center and neighborhood roadways, are extracted. Therefore, the proposed scheme of extracting forward vehicle area improves the rate of vehicle detection on the road images with complex background, and is highly efficient because of detecting vehicles within the confines of the acquired vehicle area. The superiority of the proposed algorithm is verified from experiments of the vehicle detection on road images with complex background.

• Management & Information Systems Review
• /
• v.4
• /
• pp.257-284
• /
• 2000

According as the drivers increase who have their cars, the comprehensive studies on the automobile for the traffic safety have been raised as the important problems. Visual Recognition System for radio-controled driving is a part of the sensor processor of Unmanned Autonomous Vehicle System. When a driver drives his car on an unknown highway or general road, it produces a model from the successively inputted road traffic information. The suggested Recognition System of the Road Traffic Safety Information Board is to recognize and distinguish automatically a Road Traffic Safety Information Board as one of road traffic information. The whole processes of Recognition System of the Road Traffic Safety Information Board suggested in this study are as follows. We took the photographs of Road Traffic Safety Information Board with a digital camera in order to get an image and normalize bitmap image file with a size of $200{\times}200$ byte with Photo Shop 5.0. The existing True Color is made up the color data of sixteen million kinds. We changed it with 256 Color, because it has large capacity, and spend much time on calculating. We have practiced works of 30 times with erosion and dilation algorithm to remove unnecessary images. We drawing out original image with the Region Splitting Technique as a kind of segmentation. We made three kinds of grouping(Attention Information Board, Prohibit Information Board, and Introduction Information Board) by RYB( Red, Yellow, Blue) color segmentation. We minimized the image size of board, direction, and the influence of rounding. We also minimized the Influence according to position. and the brightness of light and darkness with Eigen Vector and Eigen Value. The data sampling this feature value appeared after building the learning Code Book Database. The suggested Recognition System of the Road Traffic Safety Information Board firstly distinguished three kinds of groups in the database of learning Code Book, and suggested in order to recognize after comparing and judging the board want to recognize within the same group with Nearest Neighborhood Decision Making.

• Nuclear Engineering and Technology
• /
• v.52 no.10
• /
• pp.2221-2229
• /
• 2020

After the Fukushima Daiichi nuclear power plant (NPP) accident, level 3 probabilistic safety assessment (PSA) has emerged as an important task in order to assess the risk level of the multi-unit NPPs in a single nuclear site. Accurate calculation of the radionuclide concentrations and exposure doses to the public is required if a nuclear site has multi-unit NPPs and large number of people live near NPPs. So, there has been a great need to develop a new method or procedure for the fast and accurate offsite consequence calculation for the multi-unit NPP accident analysis. Since the multi-unit level 3 PSA is being currently performed assuming that all the NPPs are located at the same position such as a center of mass (COM) or base NPP position, radionuclide concentrations or exposure doses near NPPs can be drastically distorted depending on the locations, multi-unit NPP alignment, and the wind direction. In order to overcome this disadvantage of the COM method, the idea of a new multiple location (ML) method was proposed and implemented into a new tool MURCC (multi-unit radiological consequence calculator). Furthermore, the MURCC code was further improved for the multi-unit level 3 PSA that has the arbitrary number of multi-unit NPPs. The objectives of this study are to (1) qualitatively and quantitatively compare COM and ML methods, and (2) demonstrate the strength and efficiency of the ML method. The strength of the ML method was demonstrated by the applications to the multi-unit long-term station blackout (LTSBO) accidents at the four-unit Vogtle NPPs. Thus, it is strongly recommended that this ML method be employed for the offsite consequence analysis of the multi-unit NPP accidents.

• International Journal of Railway
• /
• v.3 no.2
• /
• pp.39-45
• /
• 2010

The RF-CBTC (Radio Frequency-Communication Based Train Control) System is a communication system in railroad systems. The communication method of RF-CBTC system is the wireless between the wayside device and on-board device. The wayside device collects its location and speed from each train and transmits the distance from the forwarding train to the speed-limit position to it. The on-board device controlling device controls the speed optimum for the train. In the case of the RF-CBTC system used in Korea, transmission frequency is 2.4 [GHz]. It is the range of ISM(Industrial Scientific and Medical equipment) band and transmission of voice and data is performed by CDMA (Code Division Multiple Access) method. So noises are made in the AWGN (Additive White Gaussian Noise) and fading environment. Currently, the SNR (Signal to Noise Ratio) is about 20 [dB], so due to bit errors made by noises, transmission of reliable information to the train is not easy. Also, in the case that two tracks are put to a single direction, it is needed that two trains transmit reliable voice and data to a wayside device. But, by noises, it is not easy that just a train transmits reliable information. In this paper, we estimated the BER (Bit Error Rate) related to the SNR of voice and data transmission in the environment such as AWGN and fading from the RF-CBTC system using the CDMA method. Also, we supposed the SNR which is required to meet the BER standard for voice and data transmission. By increasing the processing gain that is a ratio of chip transmission to voice and data transmission, we made possible voice and data transmission from maximally two trains to a wayside device, and demonstrated it by using Matlab program.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.10
• /
• pp.2489-2496
• /
• 2014

The existing ship repair tool management system based on hand writing has many problems such as frequent loss of tool and overdue. To solve this problem, same systems have adopted the bar-code system. However, the systems can't cope with a problem to substitute spurious tool for genuine one on bar-code damage. Therefore, additional validation steps are necessary in order to manage expensive ship repair tool. In this paper, we propose an image comparison method for ship repair tool management. To be more concrete, we propose a normalization method and determination conditions for image comparison to use characteristics of mobile device. The normalization method makes use of the characteristics of mobile device that provides functions of real time recording, overlapping and cropping images. The proposed method applies three conditions(sum of inner angles, size of angle, position of corner coordinates) into the comparison module. The implemented system shows good performance on change direction, lighting, size and etc. The accuracy is more than 95%.