• Current Industrial and Technological Trends in Aerospace
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• v.7 no.2
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• pp.106-114
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• 2009

Until now, The Market of aviation parts had led by OEM(Original Equipment Manufacturer) parts because of aviation industry's nature required higher reliability and safety. But recently, The interest about PMA parts in aviation market is increasing continuously with various environmental changes, such as economic stagnation, oil price rise, development of the manufacture technique and newly rising market of Asia-Pacific region. Actually, after 2006, FAA PMA approval parts are increasing at a rate of around 40,000 parts per year and 2.5% of PMA parts penetration, in 2007, in Asia-Pacific market is forecast to enlarge up to 8% in 2017. So, this paper introduces the process requirements of FAA PMA / EASA EPA and the status of PMA market in order to enhance understanding for certification for aviation parts and to review a new PMA market.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.711-721
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• 2018

In order to address housing issues, alleviate the concentration of urban populations, and resolve other issues regarding residential spaces, large residential complexes have been developed in Korea since the 1970s. The changes to the residential culture due to such development projects propagated rapidly, making the apartment complexes the most representative form of housing in Korea. In developing such large-scale complexes, plans for public open spaces, which play an important role in formulating the quality of residential environment, have been mostly the same, only utilizing the spaces remaining after planning other types of spaces. The current study looks at the case of Tama New Town development project, a Japanese new town development project that has a similar public open space system in large scale residential complex development projects in Korea. In doing so, the current study aims to identify the features of public open space plans. In the conclusion, the study first finds that various public open spaces must be reviewed and introduced in term of predicting social demands. Second, the study suggests the policy-makers should actively introduce pedestrian paths as a public open space. Third, the study deduces the planning implications of applying the principle of original landscape preservation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.8
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• pp.418-428
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• 2005

In this paper, a new probabilistic generation modeling method which can address the characteristics of changed electricity industry is proposed. The major contribution of this paper can be captured in the development of a probabilistic generation modeling considering generator maintenance outage and in the classification of market demand into multiple demand clusters for the applications to electricity markets. Conventional forced outage rates of generators are conceptually combined with maintenance outage of generators and, consequently, effective outage rates of generators are newly defined in order to properly address the probabilistic characteristic of generation in electricity markets. Then, original market demands are classified into several distinct demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the original demand. We have found that generators have different effective outage rates values at each classified demand cluster, depending on the market situation. From this, therefore, it can be seen that electricity markets can also be classified into several groups which show similar patterns and that the fundamental characteristics of power systems can be more efficiently analyzed in electricity markets perspectives, for this classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.385-399
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• 2017

Nowadays, with the development of signal processing technique, the protection to the integrity and authenticity of images has become a topic of great concern. A blind image authentication technology with high tamper detection accuracy for different common attacks is urgently needed. In this paper, an improved fragile watermarking method based on local binary pattern (LBP) is presented for blind tamper location in images. In this method, a binary watermark is generated by LBP operator which is often utilized in face identification and texture analysis. In order to guarantee the safety of the proposed algorithm, Arnold transform and logistic map are used to scramble the authentication watermark. Then, the least significant bits (LSBs) of original pixels are substituted by the encrypted watermark. Since the authentication data is constructed from the image itself, no original image is needed in tamper detection. The LBP map of watermarked image is compared to the extracted authentication data to determine whether it is tampered or not. In comparison with other state-of-the-art schemes, various experiments prove that the proposed algorithm achieves better performance in forgery detection and location for baleful attacks.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.85-92
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• 2007

This paper presents a design optimization of a new Advanced Active Blade Twist (AATR-II) blade incorporating single crystal Macro Fiber Composites (MFC) and conducts vibratory loads reduction analysis using an obtained optimal blade configuration. Due to the high actuation performance of the single crystal MFC, the AATR blade may reduce the helicopter vibration more efficiently even with a lower input-voltage as compared with the previous ATR blades. The design optimization provides the optimal cross-sectional configuration to maximize the tip twist actuation when a certain input-voltage is given. In order to maintain the properties of the original ATR blade, various constraints and bounds are considered for the design variables selected. After the design optimization is completed successfully, vibratory load reduction analysis of the optimized AATR-II blade in forward flight condition is conducted. The numerical result shows that the hub vibratory loads are reduced significantly although 20% input-voltage of the original ATR blade is used.

• Korean Institute of Interior Design Journal
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• v.14 no.1
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• pp.142-150
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• 2005

This study is arranged the principles of the preservation and restoration in pre-modern architecture, presented guideline of the Intoner restoration in there, and attempted relative-analysis by cases of Japan in curtain of Saporo Houheikan. The method of Original- restorations and Repairs must be preserved In materials and technologies in order to hand over the future generations. The process and method of restorations are the important Cultural Properties as Architecture's itself. And Restorations of industrial manufactures hold the the important position in restoration of pre-modern Architectures. Because industrial technologies are developed and forgotten in rapid. Specially, because industrial materials as curtains were apt to recognize as consumption goods, historicity in that are contained the history of fabric, industrial technologies, and relations of traditional technologies. Conclusionaly, restorations of interior materials in our country are required of \circled1the construction of workframe in search and restoration for original preservation, \circled2the conception of refaires and establishment of investigation, \circled3the stocking of restoration-technologies of pre-modern cultural properties of architectures, \circled4the recognitions of record-preservation, \circled5the improvement of organization, upbring of technicians, establishment of theorical systems.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.6
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• pp.283-291
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• 2012

In order to increase the anti-oxidation property during the tailor welding blanked hot press forming process for a high strength boron steel sheet, we performed a different coating method on the boron-steel sheet such as 87% Al - 13% Si and Fe - 8.87 Zn dipping plating procedure. However, during laser welding process, the Al-Si coated steel sheet has showed a low tensile strength and about half value of elongation than the original boron-steel sheet. Aluminum and silicon, elements of coating layer were diffused into the boron-steel matrix and have shown a low strength result than non-coated specimen. On the other hand, Zinc-coated boron-steel has expectedly showed a excellent tensile strength and micro-harness value in the welded area like original boron-steel.

• Journal of Korean Medical classics
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• v.18 no.1 s.28
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• pp.33-48
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• 2005

The purpose of this study is that translates ${\ulcorner}$Sun Gi Il Il Bun Wi Sa Si${\lrcorner}$ in the ${\ulcorner}$Young Chu(靈樞)${\lrcorner}$ as a modern words because it is hard to understand which was written by classical words. We revised the original text with the 7 other classic books and classified annotations of the 6 annotated books according to the similar contents. We classified this volume by 3 chapters, and added Hangul suffixes to the original text. The Five types of changes(五變) in the second chapter is meaning to the mutual relationships among the Five viscera and Color, Time, Day, Note, Taste. The word order of contents in the second chapter must be unified follow the Color, Time, Day, Note, Tastes. The Five types of changes in the third chapter must be revise the Five types of diseases(五病) on the bases of the ${\ulcorner}$You Kyoung(類經)${\lrcorner}$.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.804-806
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• 2005

In this paper, a new probabilistic generation modeling method which can address the characteristics of changed electricity industry is proposed. The major contribution of this paper can be captured in the development of a probabilistic generation modeling considering generator maintenance outage and in the classification of market demand into multiple demand clusters for the applications to electricity markets. Conventional forced outage rates of generators are conceptually combined with maintenance outage of generators and, consequently, effective outage rates of generators are new iy defined in order to properly address the probabilistic characteristic of generation in electricity markets. Then, original market demands are classified into several distinct demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the original demand. We have found that generators have different effective outage rates values at each classified demand cluster, depending on the market situation. From this, therefore, it can be seen that electricity markets can also be classified into several groups which show similar patterns and that the fundamental characteristics of power systems can be more efficiently analyzed in electricity markets perspectives, for this classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.2
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• pp.93-100
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• 2006

In this paper, a new-type Extended Kalman Filter (EKF) is proposed as a robust nonlinear filter for a stochastic nonlinear system. The original EKF is widely used for various nonlinear system applications. But it is fragile to its estimation errors because they give rise to linearization errors that affect the system mode1 as the modeling errors. The linearization errors are nonlinear functions of the estimation errors therefore it is very difficult to obtain the accurate error covariance of the EKF using the linear form. The inaccurately estimated error covariance hinders the EKF from being a sub-optimal estimator. The proposed filter tries to obtain the upper bound of the error covariance tolerating the uncertainty of the error covariance instead of trying to obtain the accurate one. It treats the linearization errors as uncertain modeling errors that can be handled by the robust linear filtering. In order to be more robust to the estimation errors than the original EKF, the proposed filter minimizes the upper bound like the robust linear filter that is applied to the linear model with uncertainty. The in-flight alignment problem of the inertial navigation system with GPS position measurements is a good example that the proposed robust filter is applicable to. The simulation results show the efficiency of the proposed filter in the robustness to initial estimation errors of the filter.