This work presents four mathematical remarks concluded from the mathematical analysis for the interrelationships between the dependent and independent variables that control the measures: perimeter, floor area, walls surface area and total surface area in the regular forms that have a given volume. Such forms include prismatic and pyramidal forms. The work consists of four parts, of which this first part presents the remarks of the isosceles triangular right prism. The first remark examines the effect of θ, the angle of the triangular base, on the total surface area. The second remark calculates the minimum total surface area in two cases, depending on whether angle θ is constant or variable. The third remark calculates the walls ratio and the critical walls ratio. The last remark studies the required conditions for the numerical equality in two cases, where the perimeter is equal to the area, and where the total surface area is equal to the volume. 相似文献
Indium tin oxide‐coated thin films (200 nm) are deposited on glass substrates by using R.f. sputtering technique. Here, we investigate the influence of new technique of treatment, which is called as “oil thermal annealing” on the nano‐structured indium tin oxide thin films at fixed temperature (150 °C) which improves adhesion strength, electrical conductivity and optical properties (transmittance) of the films. Oil thermal annealing is used to reduce inherent defects that may be introduced during the prepared thin film and cooling processes. Proposed technique is highly suitable for liquid crystal displays, solar cells and organic light emitting diodes, and many other display‐related applications. 相似文献
The stoichiometric association constants, K, the thermodynamic association constant, KA, and the other thermodynamic parameters such as ΔS°, ΔH° and ΔG° for the association between each of the Ca and Mg ions with benzoate, o-toloate, o-chlorobenzoate and salycylate have been determined at 25°C, 35°C and 45°C in aqueous media. Ion-selective electrode technique has been used in the measurements of Ca and Mg ion activitiesThe trend of association behavior of both Ca and Mg aromatic salts could not be explained on the basis of pKa of the mother organic acids but could be explained based on the trend of Hammet function σ of these salts themselves relative to the corresponding benzoate salt. 相似文献
Shea butter is used as an edible vegetable fat in many African countries. It can be utilized as a substitute or complete replacement for cocoa butter in various applications and plays an important role in traditional African medicinal practice. Although detection of volatile compounds by solid‐phase micro‐extraction gas‐chromatography mass‐spectroscopy (SPME‐GC‐MS) is a very reliable and reproducible technique, which can be used as an important part of authenticity checking, production monitoring and contamination detection, no published data about volatile compounds of shea butter are available so far. In this investigation, the characteristic volatiles in the headspace of original African shea butter samples were identified by using SPME‐capillary‐GC coupled to a mass selective detector. Almost 100 different volatile components were identified, e.g. fatty acids, saturated and unsaturated aldehydes and ketones, terpenes, and typical Maillard reaction products such as methylfuranes and pyrazines. Furthermore, the samples have been olfactorily evaluated by a panel of professional flavorists and trained analytical chemists. It can be stated that variations in processing conditions of shea butter result in considerable differences in the composition of headspace volatiles, detected by SPME‐GC‐MS and human olfaction. 相似文献
Multimedia Tools and Applications - Nowadays, web users frequently explore multimedia contents to satisfy their information needs. The exploration approaches usually provide linear interaction... 相似文献
Security threats are crucial challenges that deter Mixed reality (MR) communication in medical telepresence. This research aims to improve the security by reducing the chances of types of various attacks occurring during the real-time data transmission in surgical telepresence as well as reduce the time of the cryptographic algorithm and keep the quality of the media used. The proposed model consists of an enhanced RC6 algorithm in combination. Dynamic keys are generated from the RC6 algorithm mixed with RC4 to create dynamic S-box and permutation table, preventing various known attacks during the real-time data transmission. For every next session, a new key is created, avoiding possible reuse of the same key from the attacker. The results obtained from our proposed system are showing better performance compared to the state of art. The resistance to the tested attacks is measured throughout the entropy, Pick to Signal Noise Ratio (PSNR) is decreased for the encrypted image than the state of art, structural similarity index (SSIM) closer to zero. The execution time of the algorithm is decreased for an average of 20%. The proposed system is focusing on preventing the brute force attack occurred during the surgical telepresence data transmission. The paper proposes a framework that enhances the security related to data transmission during surgeries with acceptable performance.
Most schemes exhibit low robustness due to LSB’s (Least Significant Bit) and MSB’s (Most Significant Bit) based information hiding in the cover image. However, most of these IW schemes have low imperceptibility as the cover image distortion reveals to the attacker due to information hiding in MSB’s. In this paper, a hybrid image watermarking scheme is proposed based on integrating Robust Principal Component Analysis (R-PCA), Discrete Tchebichef Transform (DTT), and Singular Value Decomposition (SVD). A grayscale watermark image is twisted/scrambled using a 2D Discrete Hyper-chaotic Encryption System (2D-DHCES) to boost up the robustness/heftiness and security. The original cover image is crumbled into sparse components using R-PCA and using DTT the substantial component is additionally decomposed and the watermark will be embedded in the cover image using SVD processing. In DTT, scarcer coefficients hold the utmost energy, also provide an optimum sparse depiction of the substantial image edges and features that supports proficient retrieval of the watermark image even after unadorned image distortion based channel attacks. The imperceptibility and robustness of the proposed method are corroborated against a variety of signal processing channel attacks (salt and pepper noise, multi-directional shearing, cropping, and frequency filtering, etc.). The visual and quantifiable outcomes reveal that the proposed image watermarking scheme is much effective and delivers high forbearance against several image processing and geometric attacks.