Refik Samet

A new approach to the reconstruction of contour lines extracted from topographic maps

It is known that after segmentation and morphological operations on topographic maps, gaps occur in contour lines. It is also well known that filling these gaps and reconstruction of contour lines with high accuracy is not an easy problem. In this paper, a nontrivial semi-automatic approach to solve this problem is proposed. The main idea of the proposed approach is based on local and geometric properties such as (1) parabolic and opposite directions, (2) the differences of y-ordinate of end points, (3) changing the directions of x-axis and y-ordinate to the nearest clockwise direction and (4) avoiding the use of the second end point of a small piece of any contour line in the same mask if its other end point is used. The proposed approach was implemented on the base of many topographic maps with different resolutions and complexity. The obtained results show that the proposed approach increases accuracy and performance.

Advanced contour reconnection in scanned topographic maps

This paper presents an advanced reconnection of contour lines extracted from scanned topographic maps. In other words, this paper refers to the problem of gap filling. New properties such as 1) controlling a search mask for even number end points, 2) using the parabolic directions, and 3) back tracing less than ten pixels are added to the classical semi-automatic method to improve performance and accuracy. Proposed method has been applied to many different maps and the results of two implementations are given in this paper. An analysis and comparison of obtained results show that proposed method improves run time and accuracy about 22–44% and 12–14%, respectively.

Fault‐tolerant procedures for redundant computer systems

Real-time computer systems deployed in life-critical control applications must be designed to meet stringent reliability specifications. The minimum acceptable degree of reliability for systems of this type is ‘7 nines’, which is not generally achieved. This paper aims at contributing to the achievement of that degree of reliability. To this end, this paper proposes a classification scheme of the fault-tolerant procedures for redundant computer systems (RCSs). The proposed classification scheme is developed on the basis of the number of counteracted fault types. Table I is created to relate the characteristics of the RCSs to the characteristics of the fault-tolerant procedures. A selection algorithm is proposed, which allows designers to select the optimal type of fault-tolerant procedures according to the system characteristics and capabilities. The fault-tolerant procedure, which is selected by this algorithm, provides the required degree of reliability for a given RCS. According to the proposed graphical model only a part of the fault-tolerant procedure is executed depending on the absence or presence (type and sort) of faults. The proposed methods allow designers to counteract Byzantine and non-Byzantine fault types during degradation of RCSs from N to 3, and only the non-Byzantine fault type during degradation from 3 to 1 with optimal checkpoint time period. Copyright

A Low Complexity Algorithm for H.264/AVC Intra Prediction

Intra prediction plays an important role in H.264/AVC. To reduce the complexity of the intra prediction of H.264/AVC, this paper proposes an efficient intra prediction algorithm. First, we determine if a macro block (MB) is flat or detailed rich by comparing its texture feature with dual thresholds criterion. Then, the flat MBs will be encoded in Intra 16×16 mode and those relatively rich MBs are encoded in Intra 4×4 mode. Second, an efficient Intra 4×4 mode selection algorithm is also proposed to reduce the number of candidates of intra prediction modes. The experimental results show that the encoding time of I-frame is reduced by an average of 30%, and both the increment in output bit rate and decrement in Peak Signal-to-Noise Ratio (PSNR) are negligible.

Transfer Characteristic of a Goto Pair in Small-Size Josephson Junctions

The response of a Goto pair, based on small-size Josephson junctions, to voltage jumps has been studied within the framework of a resistive model. An analytical formula for the time of establishment of the transfer characteristic is obtained and the corresponding estimates are calculated.

Metamodeling Methodology for Modeling Cyber-Physical Systems

ABSTRACT Existing metamodeling approaches cannot effectively capture the properties of heterogeneous and multidimensional cyber-physical domains. To contribute to this area, a new metamodeling methodology for the development of metamodels with different mathematical semantics is proposed in this article. The new metamodeling architecture and the method for the development of metamodels as integrated formal systems are discussed. To prove the concept, a geometrical meta-metamodel, which allows linking physical properties of multidimensional domains with their spatial structures, is proposed.

Geometrical Meta-Metamodel for Cyber-Physical Modelling

Existing metamodels are not able to effectively capture the knowledge of multidimensional cyber-physical domains. In order to contribute to this area the approach for development of metamodels for modelling the multidimensional cyber-physical systems is considered in the paper. The geometrical meta-metamodel, allowing to link the physical properties of domains with its spatial structure, is proposed. The implementation of the metamodelling approach in the Visual Environment for Cyber-Physical Modelling is considered. The example of using the geometrical meta-metamodel for metamaterials design is given. Investigation, modeling, design and implementation of cyber-physical systems have to be considered as a new and essential part of cyber worlds.

Fuzzy Rule-Based Image Segmentation technique for rock thin section images

Image segmentation is a process of partitioning the images into meaningful regions that are ready to analyze. Segmentation of rock thin section images is not trivial task due to the unpredictable structures and features of minerals. In this paper, we propose Fuzzy Rule-Based Image Segmentation technique to segment rock thin section images. Proposed technique uses RGB images of rock thin sections as input and gives segmented into minerals images as output. In order to show an advantage of proposed technique the rock thin section images were also segmented by known Fuzzy C-Means technique. Both techniques were applied to many different rock thin section images. The obtained results of proposed Fuzzy Rule-Based Image Segmentation and Fuzzy C-Means techniques were compared. Implementation results showed that proposed image segmentation technique has better accuracy than known ones.

Recovery Device for Real-Time Dual-Redundant Computer Systems

This paper proposes the design of specialized hardware, called Recovery Device, for a dual-redundant computer system that operates in real-time. Recovery Device executes all fault-tolerant services including fault detection, fault type determination, fault localization, recovery of system after temporary (transient) fault, and reconfiguration of system after permanent fault. The paper also proposes the algorithms for determination of fault type (whether the fault is temporary or permanent) and localization of faulty computer without using self-testing techniques and diagnosis routines. Determination of fault type allows us to eliminate only the computer with a permanent fault. In other words, the determination of fault type prevents the elimination of nonfaulty computer because of short temporary fault. On the other hand, localization of faulty computer without using self-testing techniques and diagnosis routines shortens the recovery point time period and reduces the probability that a fault will occur during the execution of fault-tolerant procedure. This is very important for real-time fault-tolerant systems. These contributions bring both an increase in system performance and an increase in the degree of system reliability.

Design and implementation of highly reliable dual-computer systems

Two of the main parameters of real-time computer systems are reliability and performance. Researchers are always looking for solutions to increase the values of these parameters, which is the goal of this study. To this end, we propose an architecture for a dual-computer system that operates in real-time with fault tolerance implemented purely by hardware. The hardware, as designed and implemented, performs the following key services: 1) determination of the fault type (temporary or permanent) and 2) localization of the faulty computer without using self-testing techniques or diagnostic routines. Our design has several benefits: 1) the designed hardware shortens the recovery point time period; 2) the proposed nontrivial sequence of fault-tolerant services reduces (to two) the number of logical segments that must be re-run to recover computational processes; and 3) the determination of the fault type allows for the elimination of only computers with permanent faults. These contributions yield improvements in both the performance and reliability of the system.