• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.207-212
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• 2020

To decide a separation distance of the redundant vital equipment in a naval ship, the damage radius due to an aerial explosion should be estimated. In this research, a simplified formula for the damage radius has been developed by using existing empirical formulae for reflected shock pressure and shock lethality value of equipment. As a numerical example, the damage radius for a typical pump aboard a naval ship has been calculated by the developed formula and compared with the results calculated by Measure of Total Integrated Ship Survivability (MOTISS) which is one of survivability analysis codes verified, validated and accredited by the US Navy. Also, comparison with the results calculated by existing other simplified formulae has been made.

• Journal of Korea Water Resources Association
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• v.38 no.7 s.156
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• pp.585-593
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• 2005

Recent concerns regarding protecting, identifying, isolating, redundant routing and dewatering of subsystems of water distribution networks have led to the realization of the importance of valves in these systems. Valves serve two purposes namely, flow and pressure control and isolating subsystems due to breakage or contaminant containment. In this paper, valves are considered from the point of view of subsystem isolation. When a water main is required to be closed, it may be in general necessary to close several other pipes in addition to the broken pipe itself depending on the distribution of adjacent valves. This set of pipes is defined as a segment. In this paper a segment analysis for isolating pipes is present and based on the segment analysis, we suggested the Valve Importance Index and the 7 performance indicators to evaluate the system performance. The suggested methodology is applied to a real network to verify the applicability of the methodology.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.199-204
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• 2002

Since motion estimation and motion compensation methods remove the redundant data to employ the temporal redundancy in images, it plays an important role in digital video compression. Because of its high computational complexity, however, it is difficult to apply to high-resolution applications in real time environments. If we have information about the motion of an image block before the motion estimation, the location of a better starting point for the search of an exact motion vector can be determined to expedite the searching process. In this paper, we present an adaptive motion estimation approach bated on temporal correlations of consecutive image frames that defines the search pattern and determines the location of the initial search point adaptively. Through experiments, compared with DS(Diamond Search) algorithm, the proposed algorithm is about 0.1∼0.5(dB) better than DS in terms of PSNR(Peak Signal to Noise Ratio) and improves as high as 50% compared with DS in terms of average number of search point per motion vector estimation.

• The Journal of Korea Robotics Society
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• v.7 no.3
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• pp.182-193
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• 2012

This paper presents a new behavior planning scheme for autonomous robots, allowing them to handle various objects used in our daily lives. The key idea underlying the proposed scheme is to use affordance concepts that provide a robot with action possibilities triggered by a relation between the robot and objects around it. Specifically, the robot attempts to find the affordances and to determine the most adequate action among them. Through a series of the perception processes, robot motions can be planned and performed to complete assigned tasks. What is of particular importance from the practical point of view is a decision making capability to determine the best choice by comparing the human's body characteristics and behavioral patterns as criteria with action possibilities as alternatives. For this, the analytic hierarchy process (AHP) technique is employed to systematically evaluate the correlation between the criteria and the alternatives. Moreover, the alternatives arranged in order of priority through the decision making process enable the robot to have redundant solutions for the assigned task, resulting in flexible motion generation. The effectiveness and validity of the proposed scheme are verified by performing extensive simulations using objects of our daily use.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.65-74
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• 2012

In this paper, we explore the application of 2-D dual-tree discrete wavelet transform (DDWT), which is a directional and redundant transform, for image coding. DDWT introduces limited redundancy and allows the transform to provide approximate shift invariance and directionally selective filters while preserving the usual properties of perfect reconstruction and computational efficiency with good well-balanced frequency responses. Also, quincunx lattice yields a non separable 2D-wavelet transform, which is also symmetric in both horizontal and vertical direction. And non-separable wavelet transformation can generate sub-images of multiple degrees rotated versions. The proposed 2-D non-separable DDWT can provide efficient approximation for directional features of images schemes, such as edges and contours in images that are not aligned with the horizontal or vertical direction. Finally, non-separable image processing using DDWT services good performance.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.1-12
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• 2014

Recently, the need for non-stop service is increasing by the business mission-critical Internet banking, e-payment, e-commerce, home shopping, securities trading, and petition business increases, clustered in a single database of existing, redundant research on high-availability technologies related to technique, etc. is increasing. It provides an API based on the Active Log in addition to the technique of redundancy, ALTIBASE$^{TM}$ Log Analyzer (below, ALA), provides scalability and communication of the same model or between heterogeneous. In this paper, we evaluated the performance of ALA by presenting the design of the database system that you can use the ALA, to satisfy all the synchronization features high scalability and high availability, real-time.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.303-311
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• 2017

As new information technology emerges, companies are introducing an Enterprise Security Management system to cope with new security threats, reducing redundant investments and waste of resources and counteracting security threats. Therefore, it is necessary to construct a security evaluation metric based on related standards to demonstrate that the Enterprise Security Management(ESM) System meets security. Therefore, in order to construct a metric for evaluating the security of the ESM, this study analyzed the security quality related requirements of the ESM and constructed a metric for measuring the degree of satisfaction. This metric provides synergies through the unification of security assessments that comply with ISO/IEC 15408 and ISO/IEC 25000 standards. It is expected that the evaluation model of the security quality level of ESM will be established and the evaluation method of ESM will be standardized in the future.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.631-643
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• 2016

Currently, General Number Field Sieve(GNFS) is known as the most efficient way for factoring large numbers. CADO-NFS is an open software based on GNFS, that was used to factor RSA-704. Polynomial selection in CADO-NFS can be divided into two stages - polynomial selection, and optimization of selected polynomial. However, optimization of selected polynomial in CADO-NFS is an immense procedure which takes 90% of time in total polynomial selection. In this paper, we introduce modification of optimization stage in CADO-NFS. We implemented precomputation table and modified optimization algorithm to reduce redundant calculation for faster optimization. As a result, we select same polynomial as CADO-NFS, with approximately 40% decrease in time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.4
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• pp.705-719
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• 2014

Recently the importance of operational risk is gradually increasing in risk management of financial institute. Especially the service interruption caused by system failure can lead to customer complaints, decrease of profit and customer secession. Thus, financial industry makes diverse effort to minimize the impact caused by the system failure of IT application. Common modules are used in IT system in financial industry to exclude redundant development and to use the system efficiently. However, when a failure in common module is occurred, the risk that affects all the tasks using the common module exists. In this study, the damage affected by a failure in application program is prevented separating common module which has a large risk by task in the perspective of IT operational risk. In order to cope with damage, the research on the factors related to common module is conducted and proposes the separating common module standard for decrease of operational risk of the financial IT.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1212-1217
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• 2004

The main back-bone operation in elliptic curve cryptosystems is scalar point multiplication. The most frequently used method implementing the scalar point multiplication, which is performed in the upper level of GF multiplication and GF division, has been the double-and-add algorithm, which is recently challenged by NAF(Non-Adjacent Format) algorithm. In this paper, we propose a more efficient and novel scalar multiplication method than existing double-and-add by applying redundant receding which originates from radix-4 Booth's algorithm. After deriving the novel quad-and-add algorithm, we created a new operation, named point quadruple, and verified with real application calculation to utilize it. Derived numerical expressions were verified using both C programs and HDL (Hardware Description Language) in real applications. Proposed method of elliptic curve scalar point multiplication can be utilized in many elliptic curve security applications for handling efficient and fast calculations.