A Full Connectable and High Scalable Key Pre-distribution Scheme Based on Combinatorial Designs for Resource-Constrained Devices in IoT Network

Considering the internet of things (IoT), end nodes such as wireless sensor network, RFID and embedded systems are used in many applications. These end nodes are known as resource-constrained devices in the IoT network. These devices have limitations such as computing and communication power, memory capacity and power. Key pre-distribution schemes (KPSs) have been introduced as a lightweight solution to key distribution in these devices. Key pre-distribution is a special type of key agreement that aims to select keys called session keys in order to establish secure communication between devices. One of these design types is the using of combinatorial designs in key pre-distribution, which is a deterministic scheme in key pre-distribution and has been considered in recent years. In this paper, by introducing a key pre-distribution scheme of this type, we stated that the model introduced in the two benchmarks of KPSs comparability had full connectivity and scalability among the designs introduced in recent years. Also, in recent years, among the combinatorial design-based key pre-distribution schemes, in order to increase resiliency as another criterion for comparing KPSs, attempts were made to include changes in combinatorial designs or they combine them with random key pre-distribution schemes and hybrid schemes were introduced that would significantly reduce the design connectivity. In this paper, using theoretical analysis and maintaining full connectivity, we showed that the strength of the proposed design was better than the similar designs while maintaining higher scalability.

     

Flexible poly(styrene-ethylene-butadiene-styrene) hybrid nanofibers for bioengineering and water filtration applications

Among the thermoplastic elastomers that play important roles in the polymer industry due to their superior properties, styrene-based species and polyurethane block copolymers are of great interest. Poly(styrene-ethylene-butadiene-styrene) (SEBS) as a triblock copolymer seems to have the potential to meet many demands in different applications due to various industrial requirements where durability, biocompatibility, breaking elongation, and interfacial adhesion are important. In this study, the SEBS triblock copolymer was functionalized with natural (Satureja hortensis, SH) and synthetic (nanopowder, TiO₂) agents to obtain composite nanofibers by electrospinning and electrospraying methods for use in biomedical and water filtration applications. The results were compared with thermoplastic polyurethane (TPU) composite nanofibers, which are commonly used in these fields. Here, functionalized SEBS nanofibers exhibited antibacterial effect while at the same time improving cell viability. In addition, because of successful water filtration by using the SEBS composite nanofibers, the material may have a good potential to be used comparably to TPU for the application.     

Effect of fortification with asparagus powder on the qualitative properties of processed cheese

The qualitative properties of processed cheese (PC) fortified with different levels of asparagus powder (AP) (0.5%, 1% and 1.5% wt/wt) were evaluated during storage. AP decreased the pH and lipolysis indexes and increased the phenolic content, antioxidant activity and proteolysis of the processed cheeses. AP made the structure of the cheese more elastic, increased the rigidity and decreased the spreadability compared with the control sample, which corresponded to the results obtained using dynamic oscillatory rheometry. The results showed that AP as a rich source of bioactive components could be used for the fortification of processed cheeses.     

A Novel Approach to Analyzing the Occupancy of the Geo/Geo/∞ Queueing System

Discrete time queueing systems have been successfully used to model packet queues in computer and digital communications systems. In this article we introduce a novel approach to analyzing the Geo^X/Geo^Y/∞ queueing system, which is suitable for modelling high speed computer and communications systems. The approach is based on characterizing the system by a functional equation which is then solved recursively to give identical results to those obtained using other approaches.     

A quick neural network for computer vision of gray images

This paper presents a comparison between the traditional image processing method and the area vector concept as well as the new technique of artificial neural networks. Freeman chain coding is considered in the study, and the principle of segmentation may be based and implemented for further investigations resulting from the proposed work. The pattern recognition concept is analyzed and defined through the sigmoid function and the determination of the threshold of a gray image for an object. The block schemes for the given protocols are summarized in a single scheme for illustration and comparison purposes. The synthetic pictures are generated and investigated regarding the dependence of computer vision on the contents of the artificial neural network. The normalization technique is included to eliminate noise and zooming problems. The minimum computational time for image processing with the generated pictures is also determined. The rate of deflection in the computational time is recommended for sensing the minimum computational time according to the variation of the number of hidden units in the hidden layer. A three-layer neural network has been used. The study of gray binary imaging for color pictures is illustrated to save computational time and effort.     

Anaphylaxis in Association with Heparin-Induced Thrombocytopenia

Heparin is almost universally used as an anticoagulant during hemodialysis. Rare but serious side effects of heparin therapy include heparin‐induced thrombocytopenia (HIT) and anaphylaxis, and these may lead to significant mortality and morbidity if left unrecognized. We are reporting a patient who developed HIT followed by an anaphylactoid reaction. This 8‐year‐old girl with Joubert's syndrome developed end‐stage renal disease secondary to nephronophthisis. She had a Permacath double‐lumen hemodialysis catheter placed in the right internal jugular vein and was started on hemodialysis using an Asahi B10 65 Dialyzer on 1/28/03. The platelet count at that time was 246 × 10³/mL. Beef lung heparin was used for anticoagulation. She was admitted for living related donor renal transplant on 2/10/03 but was found to be thrombocytopenic with a platelet count of 49 × 10³/mL. The transplant was postponed, a sepsis work‐up was performed, and she was started on antibiotics pending culture results. Hemodialysis was continued with heparin anticoagulation, and despite an improvement in the platelet count she had an acute anaphylactoid reaction 2 days later. The reaction occurred 20 min after starting her hemodialysis treatment and presented as acute onset of bronchospasm, agitation, and chest discomfort. She improved with nebulized albuterol and subcutaneous epinephrine. A review of her records revealed that she had received 6 hemodialysis treatments. The platelet count on 2/3/03, after 3 hemodialysis treatments, had been 242 × 10³/mL and on 2/8/03 after 5 treatments the platelet count was 72 × 10³/mL. HIT with anaphylaxis was suspected. Heparin was discontinued and the platelet count had returned to normal within 2 days. The diagnosis was confirmed by a positive heparin‐associated antibody test. While HIT is recognized as a complication in 1–5% of patients treated with heparin and has been well described in the literature, we could only find 2 reported cases of heparin‐induced anaphylaxis and in both cases there was accompanying thrombocytopenia. This patient further illustrates a possible linkage between these two phenomena. HIT is an important cause of thrombocytopenia in a patient on hemodialysis and continued exposure to heparin may induce anaphylaxis.