On identifying codes in the hexagonal mesh

It is shown that, if r?2, there exists an (r,?2)-identifying code in the infinite hexagonal mesh with density (5r+2)/((r+2)(2r+1)) for even r and (5r+1)/((r+1)(2r+1)) for odd r. The optimal density of a (1,?2)-identifying code in the infinite hexagonal mesh is shown to be 2/3 and the optimal densities of (1,?3)- and (2,?3)-identifying codes are shown to be 1.     

Approximability of identifying codes and locating-dominating codes

We study the approximability and inapproximability of finding identifying codes and locating-dominating codes of the minimum size. In general graphs, we show that it is possible to approximate both problems within a logarithmic factor, but sublogarithmic approximation ratios are intractable. In bounded-degree graphs, there is a trivial constant-factor approximation algorithm, but arbitrarily low approximation ratios remain intractable. In so-called local graphs, there is a polynomial-time approximation scheme. We also consider fractional packing of codes and a related problem of finding minimum-weight codes.     

On perfect codes that do not contain Preparata-like codes

We show that for every length of the form 4^k - 1 there exists a binary 1-perfect code that does not contain any Preparata-like code.     

On the design of control systems that are robust in terms of performance index

A plant can typically operate in normal and emergency modes. A method of correcting the controller that is optimal in normal mode so as to make it operate satisfactorily in the emergency mode is described. The available approaches to the solution of this class of problems (see [1?C4]) are elabo-rated. In distinction from the solution of one such problem in [4], the requirement that the numbers of right poles of the transfer functions of the plant in the normal and emergency modes be identical is removed.     

Automatically identifying changes that impact code-to-design traceability during evolution

An approach is presented that automatically determines if a given source code change impacts the design (i.e., UML class diagram) of the system. This allows code-to-design traceability to be consistently maintained as the source code evolves. The approach uses lightweight analysis and syntactic differencing of the source code changes to determine if the change alters the class diagram in the context of abstract design. The intent is to support both the simultaneous updating of design documents with code changes and bringing old design documents up to date with current code given the change history. An efficient tool was developed to support the approach and is applied to an open source system. The results are evaluated and compared against manual inspection by human experts. The tool performs better than (error prone) manual inspection. The developed approach and tool were used to empirically investigate and understand how changes to source code (i.e., commits) break code-to-design traceability during evolution and the benefits from such understanding. Commits are categorized as design impact or no impact. The commits of four open source projects over 3-year time durations are extracted and analyzed. The results of the study show that most of the code changes do not impact the design and these commits have a smaller number of changed files and changed less lines compared to commits with design impact. The results also show that most bug fixes do not impact design.     

MEMS resonators that are robust to process-induced feature width variations

A stability analysis and design method for MEMS resonators is presented. The frequency characteristics of a laterally vibrating resonator are analyzed. With the fabrication error on the sidewall of the structure being considered, the first and second order frequency sensitivities to the fabrication error are derived. A simple relationship between the proof mass area and perimeter, and the beam width, is developed for single material structures, which expresses that the proof mass perimeter times the beam width should equal six times the area of the proof mass. Design examples are given for the single material and multi-layer structures. The results and principles presented in the paper can be used to analyze and design other MEMS resonators.     

Controlled systems that are robust with respect to initial data

The notion of robustness with respect to initial data is introduced. This means that several control actions map a fixed initial state to the same final state, and the same control actions map any other initial states to the same final one. The following theorem is proved: a controlled system is robust with respect to initial data iff it admits the maximal group of state symmetries. Examples of investigation of specific controlled systems on robustness with respect to initial conditions are presented.     

Team task analysis: identifying tasks and jobs that are team based

This paper presents initial information on the development and validation of three team task analysis scales. These scales were designed to quantitatively assess the extent to which a group of tasks or a job is team based. During a 2-week period, 52 male students working in 4-person teams were trained to perform a complex highly interdependent computer-simulated combat mission consisting of both individual- and team-based tasks. Our results indicated that the scales demonstrated high levels of interrater agreement. In addition, the scales differentiated between tasks that were predetermined to be individual versus team based. Finally, the results indicated that job-level ratings of team workflow were more strongly related to team performance than were aggregated task-level ratings of team-relatedness or team workflow. These results suggest that the scales presented here are an effective means of quantifying the extent to which tasks or jobs are team based. A research and practical implication of our findings is that the team task analysis scales could serve as criterion measures in the evaluation of team training interventions or predictors of team performance.     

Study on the odor classification in dynamical concentration robust against humidity and temperature changes

In this paper, we propose a method for enhancing the robustness of odor classification against the changes of humidity and temperature when the odor concentration is changing dynamically. We used amplitudes of frequency components of sensor responses at particular frequencies, instead of response magnitudes, to compose a pattern vector for the odor classification. The frequency analysis was done by using a short-time Fourier transform (STFT) and the selection of the frequency components by using a stepwise discriminant analysis. Besides the use of the STFT, we also improved the classification performance by including the humidity and temperature values to the pattern vector. Using a learning vector quantization (LVQ) neural network and training the network with wide-range data, we successfully achieved high robustness against various environment conditions even if the odor concentration was changing dynamically and irregularly under various humidity and temperature.     

On proving that certain languages are not ETOL

Summary In this paper a partial characterization for a subclass of ETOL languages is obtained. The main result binds together the number of occurrences (in words of a given ETOL language) of letters, from a given set, with their distribution. It provides a very helpful tool to prove that certain languages are not ETOL.     

Binary generalized (L,G) codes that are perfect in a weighted hamming metric

We propose a class of binary generalized (L,G) codes that are perfect in a weighted Hamming metric.     

A comparison of approaches for finding minimum identifying codes on graphs

In order to formulate mathematical conjectures likely to be true, a number of base cases must be determined. However, many combinatorial problems are NP-hard and the computational complexity makes this research approach difficult using a standard brute force approach on a typical computer. One sample problem explored is that of finding a minimum identifying code. To work around the computational issues, a variety of methods are explored and consist of a parallel computing approach using MATLAB, an adiabatic quantum optimization approach using a D-Wave quantum annealing processor, and lastly using satisfiability modulo theory (SMT) and corresponding SMT solvers. Each of these methods requires the problem to be formulated in a unique manner. In this paper, we address the challenges of computing solutions to this NP-hard problem with respect to each of these methods.     

A class of robust edge detectors based on latin squares

The theory of Latin Square experimental designs is extended to edge detection of multi-grey level pictorial data. Latin Square designs are realized using mask operations either as a square or in linear forms using ANOVA to estimate the model parameters. The test statistics are based upon the robust F-test and the thresholds are selected by an empirical interactive process. A post hoc comparison method is used to confine the edge element ambiguities to 2-pixel layer thickness in masks greater than 2 × 2 × k. Computer simulations are shown to verify the theory.     

On edge detection

Edge detection is the process that attempts to characterize the intensity changes in the image in terms of the physical processes that have originated them. A critical, intermediate goal of edge detection is the detection and characterization of significant intensity changes. This paper discusses this part of the edge detection problem. To characterize the types of intensity changes derivatives of different types, and possibly different scales, are needed. Thus, we consider this part of edge detection as a problem in numerical differentiation. We show that numerical differentiation of images is an ill-posed problem in the sense of Hadamard. Differentiation needs to be regularized by a regularizing filtering operation before differentiation. This shows that this part of edge detection consists of two steps, a filtering step and a differentiation step. Following this perspective, the paper discusses in detail the following theoretical aspects of edge detection. 1) The properties of different types of filters-with minimal uncertainty, with a bandpass spectrum, and with limited support-are derived. Minimal uncertainty filters optimize a tradeoff between computational efficiency and regularizing properties. 2) Relationships among several 2-D differential operators are established. In particular, we characterize the relation between the Laplacian and the second directional derivative along the gradient. Zero crossings of the Laplacian are not the only features computed in early vision. 3) Geometrical and topological properties of the zero crossings of differential operators are studied in terms of transversality and Morse theory.     

A robust salient object detection using edge enhanced global topographical saliency

Multimedia Tools and Applications - Complex salient object detection is the most challenging task in clutter background images. In this prevailing problem, global contrast-based methods are...     

Real-time video watermarking techniques robust against re-encoding

This paper presents a real-time watermarking codec that is robust against re-encoding attacks for high-definition videos. The codec uses a segmentation function and texture detector techniques for applying real-time watermarking to human visual systems. Experimental results confirm that the proposed scheme satisfies the requirements of invisibility, real-time processing, and robustness against format conversion and low bit-rate encoding. The proposed algorithm has the advantages of simplicity, flexibility, and low computational burden; thus, it is a suitable candidate for many novel and interesting applications such as video fingerprinting for set-top boxes, Internet protocol television, personal video recorders, and satellite boxes.     

抗几何失真的视频Hashing算法研究

文中提出了一种基于视频灰度直方图形状的Hashing算法,能有效抵抗各种常见的几何失真和视频处理操作.算法的鲁棒性原理如下:1)由于直方图的形状与像素位置无关,故基于直方图的视频Hashing算法能有效抵抗各种常见的几何攻击;2)由于在计算Hashing前对视频帧进行了平滑预处理,故算法对加噪攻击、模糊滤波、有损压缩等处理操作有很好的鲁棒性;3)由于计算Hashing前在时间轴上进行了低通滤波预处理,故算法能抵抗帧率变化、帧丢失等时域同步攻击.实验结果表明,所提出的Hashing算法有良好的唯一性和鲁棒性能.     

Perceptual video hashing robust against geometric distortions

In this paper,we propose a robust perceptual hashing algorithm by using video luminance histogram in shape.The underlying robustness principles are based on three main aspects:1) Since the histogram is independent of position of a pixel,the algorithm is resistant to geometric deformations; 2) the hash is extracted from the spatial Gaussian-filtering low-frequency component for those common video processing operations such as noise corruption,low-pass filtering,lossy compression,etc.; 3) a temporal Gaussian-filtering operation is designed so that the hash is resistant to temporal desynchronization operations,such as frame rate change and dropping.As a result,the hash function is robust to common geometric distortions and video processing operations.Experimental results show that the proposed hashing strategy can provide satisfactory robustness and uniqueness.