Discrete‐time sector based hands‐off control for nonlinear system

This article presents a hands‐off control design for discrete‐time nonlinear system with a special type of nonlinear sector termed as “discrete‐time sector.” The design method to define the boundary of a discrete‐time sector is done with control‐Lyapunov function. The generalization of nonlinear system is viewed in the perspective of a comparison function. By means of a proposed sector, a switching control is designed such that no control action is experienced inside the sector thus, saving unnecessary control efforts. However, to study the robustness for discrete‐time system, a hands‐off control is modified to ensure the monotonic decrease in the energy of the system. Finally, the proposed approach is verified with the simulation results.     

Forensic image analysis using inconsistent noise pattern

With the advancement of image acquisition devices and social networking services, a huge volume of image data is generated. Using different image and video processing applications, these image data are manipulated, and thus, original images get tampered. These tampered images are the prime source of spreading fake news, defaming the personalities and in some cases (when used as evidence) misleading the law bodies. Hence before relying totally on the image data, the authenticity of the image must be verified. Works of the literature are reported for the verification of the authenticity of an image based on noise inconsistency. However, these works suffer from limitations of confusion between edges and noise, post-processing operation for localization and need of prior knowledge about an image. To handle these limitations, a noise inconsistency-based technique has been presented here to detect and localize a false region in an image. This work consists of three major steps of pre-processing, noise estimation and post-processing. For the experimental purpose two, publicly available datasets are used. The result is discussed in terms of precision, recall, accuracy and f1-score on the pixel level. The result of the presented work is also compared with the recent state-of-the-art techniques. The average accuracy of the proposed work on datasets is 91.70%, which is highest among state-of-the-art techniques.

     

A cone penetration test for workability of fibre reinforced concrete

An attempt is made to develop a new workability test for fibre-reinforced concrete. The depth of penetration by a cone of specific dimensions and weight is observed to consistently reflect the workability of fibre-reinforced concrete in the fresh state. An extensive experimental investigation in which various conventional workability tests and the new cone penetration, test are conducted on fresh fibre concrete is described. The effect of fibre content, fibre geometry and water/cement ratio on workability as reflected by slump, ACI inverted cone, V-B time and the new cone penetration test are reported. Cones of different weights and angles are tried and it is observed that the penetration in millimetres by a cone of 4 kg weight and 30° apex angle may be taken as a measure of the workability.     

A survey on analyzing encrypted network traffic of mobile devices

International Journal of Information Security - Over the years, use of smartphones has come to dominate several areas, improving our lives, offering us convenience, and reshaping our daily work...     

Adaptive reallocation of cybersecurity analysts to sensors for balancing risk between sensors

Cyber Security Operations Center (CSOC) is a service-oriented system. Analysts work in shifts, and the goal at the end of each shift is to ensure that all alerts from each sensor (client) are analyzed. The goal is often not met because the CSOC is faced with adverse conditions such as variations in alert generation rates or in the time taken to thoroughly analyze new alerts. Current practice at many CSOCs is to pre-assign analysts to sensors based on their expertise, and the alerts from the sensors are triaged, queued, and presented to analysts. Under adverse conditions, some sensors have more number of unanalyzed alerts (backlogs) than others, which results in a major security gap for the clients if left unattended. Hence, there is a need to dynamically reallocate analysts to sensors; however, there does not exist a mechanism to ensure the following objectives: (i) balancing the number of unanalyzed alerts among sensors while maximizing the number of alerts investigated by optimally reallocating analysts to sensors in a shift, (ii) ensuring desirable properties of the CSOC: minimizing the disruption to the analyst to sensor allocation made at the beginning of the shift when analysts report to work, balancing of workload among analysts, and maximizing analyst utilization. The paper presents a technical solution to achieve the objectives and answers two important research questions: (i) detection of triggers, which determines when-to reallocate, and (ii) how to optimally reallocate analysts to sensors, which enable a CSOC manager to effectively use reallocation as a decision-making tool.     

A new single-component low-cost emitter etch-back process for silicon wafer solar cells

A way of achieving lightly doped emitter is a combination of a heavy emitter diffusion and emitter etch back, which has an added advantage of phosphorous diffusion gettering. However, this chemical emitter etch-back process must fulfil some critical requirements, e.g. cost-effectiveness, near-conformal Si etching even after deep emitter etch back, controlled Si etch rate, post-etch clean Si surface and lowest safety issues in chemical handling and drainage. In this work, we report a new low-cost (less than 1 US Cents/wafer), single-chemical, non-acidic, high-throughput emitter etch-back process for tube-diffused emitters for crystalline Si wafers. This process uses only sodium hypochlorite solution at 80 °C as the Si etchant. This process is versatile with its applications on phosphorous and boron tube-diffused monocrystalline Si and phosphorous tube-diffused multicrystalline Si wafers. The preparation, usage and drainage of this highly diluted solution are easy and safe. The Si etching process leads to excellent spatial uniformity over large-area Si wafers (243 cm²). With deep etch back resulting in a change of sheet resistance by ~60 Ω/sq, the standard deviation value changes by only 2.7%. High surface conformity in the etch-back surface is evident from reflectance studies. Quasi-steady-state photoconductance and photoluminescence imaging are used to demonstrate improved electrical parameters of the etch-back wafers.     

Multipronged,strategic delivery of paclitaxel-topotecan using engineered liposomes to ovarian cancer

Context: Synergistically active combinations have been used to enhance therapeutic efficacy for ovarian cancer chemotherapy.

Objective: The synergistically active combination of paclitaxel-topotecan (Pac-Top; 20:1, w/w) were loaded into folate-anchored PEGylated liposomes (FPL-Pac-Top) for safe and effective treatment of ovarian cancer.

Materials and methods: Coupling reactions were carried out using carbodiimide chemistry and confirmed by infrared spectral analysis. These liposomes were studied for shape and physical interaction (and integrity), in vitro drug release kinetics, hemolytic toxicity, ex vivo pharmacodynamics in OVCAR-3 cell lines, and pharmacokinetics in ovarian tumor-bearing mice.

Results: The differential scanning calorimeter studies exhibited melting of liposomes (～150?nm) at ～41?°C. The drug(s) release from liposomes followed Fickian diffusion model. The hematological studies revealed insignificant toxicity to blood cells. In vivo studies showed long circulatory behavior (increased AUC_0–t and AUMC_0–t and MRT) and selective accumulation of FPL-Pac-Top in the ovaries. FPL-Pac-Top showed less necrosis and more apoptosis in flow cytometry. Kaplan–Meier survival analysis revealed the doubling of the survival time with FPL-Pac-Top in comparison to Pac-Top solution.

Discussion and conclusion: Potentiated anti-cancer activity of FPL-Pac-Top was attributed to multiple features viz. thermosensitivity, long circulatory nature and targetability. Such approach could be a paradigm chemotherapeutic approach for safe and effective targeting of cancer.     

A wideband rectangular and circular ring‐shaped patch antenna with gap coupled meandered parasitic elements for wireless applications

A new design of a gap coupled rectangular patch antenna with meandered parasitic elements and a circular ring at the feed line has been proposed for Bluetooth, WLAN, WiMAX, C, and X band applications. Multibands at 1.26 to 1.36 GHz, 1.83 to 3.81 GHz, 7.6 to 7.85 GHz, 9.6 to 10.74 GHz, and 13.58 to 14.23 GHz with impedance bandwidth of 6.0% and 70.21%, 3.23%, 11.2%, and 4.67%, respectively, are observed. Multiple bandwidth enhancement techniques such as using symmetrical meandered parasitic patches, gap coupling, and defected ground have been employed in one design. Circular ring feed structure and meandered parasitic patches enhance the percentage impedance bandwidth from 12.11% to 70.21%.     

A High Resolution Assessment of Water Footprint of Wheat to Understand Yield and Water Use Heterogeneity

Efficient water use remains a major challenge globally. Semi-arid regions of the eastern plains of the state of Uttar Pradesh are no different. With stagnating yields and increased input achieving homogeneity in crop yield remains the only way to increase production. Water being the main drive, its judicious use is to be encouraged. Heterogeneity in water usage resulting in yield heterogeneity has to be quantified. It explains the extent of problem. This research conducted at Samrakalwana village at Allahabad reveals that a 36.12 % heterogeneity in water usage results in wheat yield heterogeneity of 44.04 %. Based upon this, management practices can be recommended to the farmers to minimize yield gap. Water footprints for wheat were obtained. The obtained water footprints for wheat were found to vary between 9844 to 2951 l/Kg. The water productivity ranged from 3.88 to 1.01 Tonnes/m³. This huge variation also explains the large heterogeneity is present in utilizing existing water as a resource at the Samrakalwana village.