Proposal of an alternating bending technique for evaluating low‐to‐high cycle fatigue of structural steels

This paper proposes an alternating bending technique for evaluating fatigue life in the low‐to‐high cycle fatigue regime. A method was developed for estimating the stress, elastic strain, and plastic strain ranges of a plastically deformed specimen subjected to alternating bending with consideration of stress and strain distributions. To evaluate its effectiveness, fatigue testing was conducted using a specimen made of a steel used for pressure vessels. The stress, elastic strain, and plastic strain ranges could be obtained during cyclic bending. The elastic strain amplitude life and plastic strain amplitude life curves were linear in a log–log plot in the low‐to‐high cycle fatigue regime. Hence, the fatigue life under alternating bending could be evaluated using the proposed strain‐based approach. However, these curves could not be predicted using equations with parameters obtained from tensile testing, such as the universal slope method, due to the strain gradient in the specimen.     

Photoluminescent distinction among plant life forms using phosphate buffered saline extract solutions

Photoluminescence of plant extract solutions has been investigated for discrimination of plant life forms (grasses, forbs, and shrubs) using principal component analysis (PCA). Clippings from each of six plant species representing three different plant life forms potentially found in the diets of free-ranging herbivores in the Chihuahuan Desert of North America were investigated for possible discernment. These plants included Sporobolus flexuosus (mesa dropseed, a grass), Pleuraphis mutica (tobosa, a grass), Dimorphocarpa wislizenii (spectacle pod, a forb), Sphaeralcea incana (pale globemallow, a forb), Flourensia cernua leaves (tarbush, a shrub), and Atriplex canescens leaves and stems (fourwing saltbush, a shrub). Emission spectra (370-600 nm) from phosphate buffered saline (PBS) extract solutions (pH 2.2, 7.5 and 12.5) were recorded for each plant with excitation at 365 nm. Use of PBS minimized chlorophyll interference. Discernment among plant life forms within these plant species was achieved.     

Design and analysis of two stream ciphers based on chaotic coupling and multiplexing techniques

In this paper, we design and implement two new stream ciphers based on Pseudo Chaotic Number Generators (PCNGs) which integrate discrete chaotic maps, namely, Piecewise Linear Chaotic Map (PWLCM), Skewtent and Logistic map. They are weakly coupled by a predefined matrix A for the first PCNG and they are coupled by a binary diffusion matrix D for the second one. Each PCNG includes a chaotic multiplexing technique that allows the enhancement of the robustness of the system. The structure is implemented with finite precision N = 32 bits in C language. Security performance of the proposed stream ciphers is analysed and several cryptanalytic and statistical tests are applied. Experimental results highlight robustness as well as efficiency in terms of computation time of these two stream ciphers.     

An approach to radar imaging using the spherical projection density concept*

High resolution radar imaging is used to perform target signature analysis. In this paper, we present a comparative study of diverse 2- D imaging methods on spherical waves, such as sar processing and its modes, ssar and isar as well as holography, whose mathematical formulation is identical by using the spherical projection density function, although the measurement technique are quite different. We show that azimuth processing is unified, and under some conditions range processing can be unified. In order to reconstruct the fixed target side looking radar image, we have developed an idea based on the transformation of antenna lateral displacement as a function of equivalent angular displacement, and then the 1- D images coherent summation algorithm of classical holography can be used.     

An optimization tool for operational tolerances allocation, work in process inventory minimization, and machines assignment in a discrete part manufacturing environment

In the last two decades, many researchers have addressed the superior system performance resulted from the integration of process planning and scheduling functions. However, most of the published solution methods in this field fall short in three accounts. First, while integrating with scheduling, they ignore the checking of process planning feasibility with respect to tolerances allocation. Thus, operational tolerances may stackup beyond the blue print tolerances making the process plans infeasible. Second, they ignore the machines capabilities during the integration modeling which make these solution models practically inapplicable. Third, they focus on time consideration, such as makespan or lateness, and do not consider manufacturing cost related to operations-machines assignment. This paper presents an innovative model for the integration of process planning and scheduling in a job-shop environment. The model simultaneously serves three purposes: allocating operational tolerances while minimizing its manufacturing cost, minimizing the work in process inventory, and figuring the operation-machine assignments. The preemptive-goal programming method is used to solve the proposed multiobjective non-linear mixed integer model, and an implementation example is presented to demonstrate the effectiveness of the proposed modeling approach.     

Using an electronic spreadsheet to analyze manufacturing flow systems

Contemporary use of electronic spreadsheets has centered on financial- and accounting-type analysis. Models are described in this paper that facilitate the use of an electronic spreadsheet for analyzing the flow of work in process through manufacturing system. It is shown that the spreadsheet-modeled analytic approach works best for the flow shop configuration: however, some job shop deviations can be considered. Stochastic elements must be approximated, but results are surprisingly close to those that come from the same system modeled with FORTRAN-based languages such as SLAM or INSIGHT. [A. A. Pritsker & C. D. Pegden, Introduction to Simulation and SLAM. Halsted Press, New York (1979); S. D. Roberts, Simulation Modeling and Analysis with INSIGHT. Regenstrief Institute for Health Care, Indianapolis (1982).] The advantages, limitations and assumptions of spreadsheet simulation and analysis models are discussed at length.     

Polarimetric observation of forest cover in radar remote sensing

In this paper, and from the received waves, we investigate a number of Polarimetric radar techniques to characterize the polarization response of forest cover, using the example of the Landes Forest. Magnitude, as well as phase difference and amplitude ratios between the Polarimetrie channels, which are closely related to the texture of the scene, offer reliable means for data characterization and discrimination purposes. The statistical properties of high resolution Polarimetrie sar are investigated, using the K distribution to model the received amplitude of each area selected. This distribution is derived with a parameter, a, which is closely related to the heterogeneity of the ground cover, and thus provides a good tool for discriminating among different regions. From the Stokes matrix, the co- and crosspola-rized signatures are constructed, for both clear cut and full-grown tree regions, in order to identify the predominant scattering mechanisms contributing to total measured backscatter.