Security analysis and improvement of an active watermarking system for image tampering detection using a self-recovery scheme

Multimedia Tools and Applications - This paper analyses the security of an effective SVD-based image tampering detection and self-recovery scheme that has been recently proposed by S. Dadkhah et...     

Asymmetric Thioethers as Building Blocks for Chiral Monolayers

There is a growing interest in chirality at surfaces from both a fundamental and an enantioselective reactions/separations viewpoint. We report on the homochiral self-assembly of asymmetric thioethers that become chiral upon binding to a surface. We focus on the adsorption of butyl methyl sulfide and a fluorinated analogue on Au(111) surfaces.     

A New Full‐Order Sliding Mode Observer Based Rotor Speed and Stator Resistance Estimation for Sensorless Vector Controlled Pmsm Drives

Sensorless control of a permanent magnetsynchronous motor (PMSM) at low speed remains a challenging task. In this paper, a sensorless vector control of PMSM using a new structure of a sliding mode observer (SMO) is proposed. To remove the mechanical sensors, a full‐order (FO‐SMO) is built to estimate the rotor position and speed of PMSM drives. The FO‐SMO, which replaces a sign function by a sigmoid function, can reduce the chattering phenomenon. In order to overcome time delay, we cancel the low pass filter. This sensorless speed control shows great sensitivity to stator resistance and system noise. To improve the robustness of sensorless vector control, a full‐order SMO technique has been used for stator resistance estimation. A novel stator resistance estimator is incorporated into the sensorless drive to compensate for the effects of stator resistance variation. The validity of the proposed FO‐SMO with a 1.1 kw low‐speed PMSM sensorless vector control is demonstrated by experiments. In this paper, experimental results for FO‐SMO, back‐EMF SMO and MRAS techniques were obtained with fixed point DSP‐based (TMS320F240).     

Simulating the task-level control of human motion: a methodology and framework for implementation

A task-level control framework is proposed for providing feedback control in the simulation of goal-directed human motion. An operational space approach, adapted from the field of robotics, is used for this purpose. This approach is augmented by a significant new extension directed at addressing the control of muscle-driven systems. Task/posture decomposition is intrinsically exploited, allowing human musculoskeletal properties to direct postural behavior during the performance of a task. This paper also describes a simulation architecture for generating musculoskeletal simulations of human characters. The evolving capabilities of the collective environment are directed toward autonomously generating realistic motion control for virtual actors in interactive computer graphics applications, as well as synthesizing the control of human-like motion in robotic systems.     

Thymoquinone-Loaded Chitosan Nanoparticles as Natural Preservative Agent in Cosmetic Products

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, the natural terpene thymoquinone was encapsulated in chitosan nanoparticles. The nanoparticles were characterized by DLS and TEM, showing a particle size of 20 nm. The chemical structure, thermal properties, and release profile of thymoquinone were evaluated and showed a successful stabilization and sustained release of terpenes. The antimicrobial properties of the nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing high antimicrobial properties. Furthermore, natural moisturizing cream inoculated with the aforementioned microorganisms was formulated with thymoquinone-chitosan nanoparticles to evaluate the preservative efficiency, indicating its promising use as a preservative in cosmetics.     

An accurate time-to-digital converter based on a self-timed ring oscillator for on-the-fly time measurement

This paper proposes a new architecture of a time-to-digital converter (TDC) based on a self-timed ring (STR) oscillator with sub-gate delay resolution. The proposed TDC can virtually achieve as fine as desired time resolution by simply increasing its number of stages thanks to the STR unique features. Exploiting the phase difference between events propagating in the same STR without collision, this TDC benefit from a uniform phase distribution. Thus, under certain conditions, a regular time base can be generated and a compact readout algorithm can be applied. Moreover, the proposed technique allows on-the-fly time measurement on fast non-periodic signals. As a proof-of-concept, an STR-based TDC with only 9-stages has been simulated using 28 nm FDSOI technology. A time resolution of 8.9 ps has been achieved. Without using calibration, the measured DNL and INL are 0.44 and 0.40 LSB, respectively. Simulation results point out the advantage of this TDC in terms of measurement accuracy and state the limit of the on-the-fly measurement according to the dependency between the jitter and the time resolution.     

Contribution of imaging in intestinal intussusception in the adult. Apropos of a case of ileocolic intussusception secondary to cecal lipoma

On the basis of a case of ileocolonic intussusception in a 35-year-old patient secondary to an obstructive lipoma of the caecum, the authors review the literature and discuss the clinical and radiological aspects of this disease. The diagnosis was established by CT scan and barium enema before surgery. Adult intussusception is a rare disease, which does not have any specific clinical features. Radiological imaging is the only complementary investigation which can suggest the diagnosis.     

Structural,Elastic, Electronic,and Magnetic Properties of the Full-Heusler Compounds Ti<Subscript>2</Subscript>Ni<Emphasis Type="Italic">X</Emphasis> (<Emphasis Type="Italic">X</Emphasis>= Al,Ga, and In)

We present a quantum-mechanical first-principle calculation of the structural, elastic, electronic, and magnetic properties of the full-Heusler compounds Ti₂NiX (X= Al, Ga, and In). The calculation uses the full-potential linearized augmented plane waves plus local orbital method to describe Ti₂-based Heusler alloys. The results show that these compounds exhibit half metallic characteristics over a wide range of mesh parameters and obey the Slater–Pauling rule, which states that the total magnetic moment per unit cell M _t = Z _t? 18 for half-Heusler compounds XYZ and M _t = Z _t? 24 for full-Heusler X ₂ YZ compounds. For these new alloys Ti₂NiX (X= Al, Ga, and In), we initially considered the two possible L2₁ structures AlCu₂Mn and CuHg₂Ti. However, two subsequent structural studies showed that only the CuHg₂Ti-like structure is half metallic. Over a wide range of mesh parameters, the calculations give a total magnetic moment of 3.00 μ _B. These results suggest that Ti₂NiX (X= Al, Ga, and In) are promising materials for spintronic applications.     

Pivoting based manipulation by a humanoid robot

In this paper we address whole-body manipulation of bulky objects by a humanoid robot. We adopt a “pivoting” manipulation method that allows the humanoid to displace an object without lifting, but by the support of the ground contact. First, the small-time controllability of pivoting is demonstrated. On its basis, an algorithm for collision-free pivoting motion planning is established taking into account the naturalness of motion as nonholonomic constraints. Finally, we present a whole-body motion generation method by a humanoid robot, which is verified by experiments.     

Economic growth and pollutant emissions in Tunisia: An empirical analysis of the environmental Kuznets curve

This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961–2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO₂) and sulfur dioxide (SO₂) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO₂ emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO₂ emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one of unidirectional causality with income causing environmental changes and not vice versa, both in the short-run and long-run. This implies that an emission reduction policies and more investment in pollution abatement expense will not hurt economic growth. It could be a feasible policy tool for Tunisia to achieve its sustainable growth in the long-run.