• Journal of the Korean Society of Industry Convergence
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• v.5 no.1
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• pp.27-32
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• 2002

In this study, estimate of Mechanical Properties depending on Injected direction in Polymer for Automobile Application. The used materials is polyamid(nylon6), polypropylene(PP) of a simple component and its mixed, reinforced glass fiber(15%) in polyamid. One side direction of a simple component is highest strength and the two sides direction of multicomponent appear lowest strength. This is caused by effects of weldline, imperfect fusion and impregnation of multicomponent. To improve mechanical properties, it is necessary to minimize of weldline, compatibility, perfect fusion and impregnation in multicomponent polymer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1427-1437
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• 2000

In the authors＇ preceeding paper, an improved component mode synthesis (CMS) technique in which experimental data as well as finite-element data are available in sub-systems has been proposed. Thi s technique, called an improved experimental free-interface method (IEFIM), has been proved to be more accurate and more efficient than the conventional experimental CMS method based on McNeal's formulation. It is due to the facts that dynamic residual terms as well as static ones are compensated from experimentally obtained FRFs and that FRFs measured on any frequencies can be used for the compensation. In this paper, the technique is applied to the component mode synthesis of a car body structure. As a result, the applicability of the technique to a large structure is demonstrated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.548-555
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• 2007

Typical helicopter simulation programs rely on differential equations of a closed form. However, since these equations are derived using various assumptions, their usefulness is limited to small flight regions and specific model types. This paper presents a component based rotorcraft simulation program. The program adopts methods of multi-body dynamics and is written in an object-oriented programming language. The program was validated using an AH-1G helicopter simulation. The trim results are well matched with flight test data. It is also shown that program is capable of running in real-time on a desktop computer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2289-2295
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• 2015

The paper presents the incidence rates of malignant tumors of the central nervous system assessed by the component analysis. The data on primary registered cases of malignant tumors of the central nervous system in the country were used as the material of the study for the period from 2004 to 2011. A general trend of increase in the number of patients with malignant tumors of the central nervous system in Kazakhstan was determined and the potential of their increase was evaluated, which can be due to changes in the morbidity risk and age specifics, as well as the increase in population.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.69-77
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• 2011

In a large scale robot system, one of important problems is software integration, which involves three elements: modularity, reusability and stability. By these issues, the degree of convenience of system integration, its required time and the performance of the system stability can be determined. In addition, the convenience of system management can be determined by the degree of completion of service components. This paper explains the template based service component (TBSC) for the integration of service components in networked robot. The important characteristics of TBSC are automatical execution and recovery process by a PnP supporting robot framework, which helps a system operator to manage a robot system comfortably. For easy implementation and system stability, we provide a service component creator and a verification tool to developers.

• Journal of Aerospace System Engineering
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• v.6 no.1
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• pp.13-18
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• 2012

This paper presents a structural health monitoring method of aircraft reciprocating engine using Principal Component Analysis (PCA) which analyzes vibration expressed by Averaged Normalized Power Spectral Density (ANPSD). Because ANPSD of the rotating shaft is sensitive to the rotating speed, this paper proposes to use a post-processing method of ANPSD is used to reduce the sensitivity. The PCA extracts compressed information from the post-processed ANPSDs and the information means the difference between current and normal cases of the engine. The experimental results demonstrate the feasibility and effectiveness of the proposed method to detect abnormal cases of the engine.

• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.22-28
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• 2006

Operation of a microturbine was simulated on the basis of component characteristic parameters obtained from performance test. Characteristic parameters, such as compressor and turbine efficiencies, recuperator effectiveness as well as turbine inlet temperature, were obtained for a wide operation range. Component characteristics including performance maps and characteristic curves were generated using measured data. Based on the component characteristics, a simulation program was constructed and operation of the microturbine was simulated, and the simulated results were compared with the measured data to verify the program. Also, influence of variation in the power control scheme on the operating characteristic and performance of the engine was simulated. The simulation program can be used for predicting operation of both healthy and degraded engine conditions.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.709-729
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• 2008

This paper describes a three-dimensional dynamic finite element analysis of two/multiple shots impacting on a metallic component. The model is validated against a published numerical study. An extensive parametric study is conducted to investigate the effect of shot impacting with overlap on the resulting residual stress profile within the component, including time interval between shot impacts, separation distance between the impacting points, and impacting velocity of successive shots. Several meaningful conclusions can be drawn regarding the effect of shot impacting with overlap.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.142-150
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• 2018

This paper describes the algorithm that lowers the dimension, maintains the object recognition and significantly reduces the eigenspace configuration time by combining the edge orientation histogram and principle component analysis. By using the detected object region as a recognition input image, in this paper the object recognition method combined with principle component analysis and the multi-layer network which is one of the intelligent classification was suggested and its performance was evaluated. As a pre-processing algorithm of input object image, this method computes the eigenspace through principle component analysis and expresses the training images with it as a fundamental vector. Each image takes the set of weights for the fundamental vector as a feature vector and it reduces the dimension of image at the same time, and then the object recognition is performed by inputting the multi-layer neural network.

• The Korean Journal of Applied Statistics
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• v.21 no.6
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• pp.1109-1116
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• 2008

Biplots are the multivariate analogue of scatter plots. They are useful for giving a graphical description of the data matrix, for detecting patterns and for displaying results found by more formal methods of analysis. Nevertheless, when some values are missing in data matrix, most biplots are not directly applicable. In particular, we are interested in the shape variability of principal component biplot which is the most popular in biplots with missing values. For this, we estimate the missing data using the EM algorithm and mean imputation according to missing rates. Even though we estimate missing values of biplot of incomplete data, we have different shapes of biplots according to the imputation methods and missing rates. Therefore we propose a RMS(root mean square) for measuring and comparing the shape variability between the original biplots and the estimated biplots.