The wireless sensor network (WSN) signifies to a gathering of spatially spread and committed sensors for observing and logging the physical states of the environment and for organizing the information gathered at the central Base station. Many security threats may affect the functioning of these networks. Security of the data in the system depends on the cryptographic procedure and the methods where encryption and decryption keys are developed among the sensors. Symmetric key foundation is one of the best applicable ideal models for safe exchanges in WSNs. The main goal is to improve and evaluate certain issues, such as node attack, to provide better key strength, connectivity, security for node interaction, and throughput. Uniform Balanced Incomplete Block design (UBIBD) is used to generate the keys allocated by the base station to the cluster head. The cluster head distributes keys to its members using Symmetric Balanced Incomplete Block design (SBIBD), and the keys are refreshed on a regular basis to avoid out-of-date entries. In wireless sensor networks, compromised nodes can be used to inject false reports. The concept of interacting between sensor nodes using keys and establishing a secure connection aids in ensuring the network's security.

The widespread and daily increasing application of heterogeneous catalysts in the industry has caused to using new techniques in catalysts design for reducing costs and accelerating research, development and commercialization. The application of combinatorial catalysis methods as new techniques in catalysts design are under development. At this paper, combinatorial catalysis methods including of experimental design, genetic algorithm and meta-modeling has been reviewed.

Key distribution is an important problem in wireless sensor networks where sensor nodes are randomly scattered in adversarial environments. Due to the random deployment of sensors, a list of keys must be pre-distributed to each sensor node before deployment. To establish a secure communication, two nodes must share common key from their key-rings. Otherwise, they can find a key- path in which ensures that either two neighboring nodes have a key in common from source to destination. combinatorial designs are powerful mathematical tools with comprehensive and simple structures. Recently, many researchers have used combinatorial designs as key pre-distribution scheme in wireless sensor networks. In this paper we consider a hybrid key pre-distribution scheme based on Balanced Incomplete Block design. We consider a new approach for choosing key-rings in the hybrid symmetric design to improve the connectivity and resilience. Performance and security properties of the proposed scheme are studied both analytically and computationally. The obtained results show that our scheme provides better resilience than symmetric design.

Introduction: Compressed air is a versatile energy source used in various applications. However, pumping water with compressed air requires specific designs. Various designs have been proposed for pumping water using compressed air. Some of these designs include Air jet pumps, air-lift pumps, diaphragm pumps, and hydro-pneumatic pumps (discrete flow). The hydro-pneumatic pump is composed of a chamber with two unidirectional valves for intake and discharge, separated by a well. Additionally, it includes an internal tube connected from the top to the outlet unidirectional valve. As compressed air enters the chamber, it applies pressure on the water surface within the chamber, resulting in the closure of the intake valve and the opening of the outlet valve, facilitating the upward pumping of water through the internal tube. Studies have been carried out in the field of jet pumps and air-lift pumps. However, the notion of enhancing flow rate and efficiency by integrating the pumping mechanisms of these pumps gave rise to the original idea of developing a hybrid water pump with a compressed air driver. The primary goal was to approach the efficiency of a hydro-pneumatic pump and simplify the design, allowing water pumping without the need for sensors or control systems. Materials and Methods: To assess the compressed air water pump and compare its performance with a hydro-pneumatic pump, a prototype with similar dimensions was constructed. By turning on or off and combining three compressed air nozzles within the pump structure, it was possible to operate the combinatorial compressed air pump in four different modes. During field experiments, the performance, which included measuring input air pressure, flow rate, and water pumping height, was measured. Additionally, the efficiency of the combinatorial compressed air pump was calculated under experimental conditions. Field experiments was conducted using a factorial design in randomized blocks. Treated variables included immersion depth (4 levels), inlet air pressure (6 levels), pump types and their working modes (5 levels). Discharge flow rates and water pumping height were measured across four replicates. at post processing, pumping efficiency calculated. Analysis of variance and post-hoc tests were conducted to analyze the significant effects of treatment variables and their interactions. to identify the best level for each treatment across different levels of other treatments, interaction slicing was employed. result was presented in charts and tables.Results: The variance analysis revealed a significant difference at the 1% confidence level among pump types, Immersion depth, input air pressure, and their interactions on water pump flow rate. Increasing submergence depth led to higher flow rates in the hydro-pneumatic pump, combinatorial pneumatic pump, Bubble pump, Bubble & Airlift combined pump, and air-lift pump. Additionally, raising input air flow resulted in increased water pumping rates for all types of pumps.The hydro-pneumatic pump exhibited higher flow rates compared to other pumps, attributed to its positive displacement structure. The flow rate in all pumps increased with higher input air pressure due to the increase in air flow.The variance analysis on pump efficiency showed significant differences at the 1% confidence level in input air pressure levels, Immersion depth, pump type, and their interactions. With increased Immersion depth, pump efficiency rose in the following order: combinatorial pneumatic pump, hydro-pneumatic pump, Bubble pump, Bubble & Airlift combined pump and air-lift pump, and air-lift pump. The combinatorial pneumatic pump showed the most positive impact of Immersion depth on efficiency.Immersion depth, inlet air pressure, and pump type significantly impacted discharge rate and pump efficiency. With increased immersion depth and air pressure, discharge and efficiency rose for all pump models and operating modes. The hydro-Pneumatic pump achieved higher efficiency and discharge due to its different structure. At 2m immersion depth, the best performance among all pump models and modes was observed: Airlift pump (10.3% efficiency), Bubble pump (20.8%), Bubble & Airlift Combined pump (19.3%), Pneumatic Combined Pump (27.1%), and Hydro-Pneumatic pump (25.2%). Discussion: While the hydro-Pneumatic pump offered superior performance, the compressed air pump's simpler structure and lack of electronic control circuitry present advantages. Future research could explore optimizing the compressed air pump design for improved efficiency while maintaining its structural simplicity. Due to structural differences, the hydro-pneumatic pump exhibits significantly higher efficiency (approximately 54%). It was expected that this efficiency would be maintained with increasing pressure, but due to the limited immersion depth in the experiments and dimensional mismatch of the pump with high input air pressure, we observed a decrease in efficiency at higher pressures. This indicates that for each submergence depth and pump head, there is an optimal pressure that the pump dimensions should be designed to suit.

In this paper, effect of the different random road inputs in the form of combinatorial profile on the nonlinear and active quarter car model with two-degree of freedom has been analyzed. Bi-objective optimization processes using differential evolution algorithm with fuzzified mutation along with non-dominated sorting algorithm and crowding distance criterion have been carried out. Further, in current work, the hybrid usage of sliding mode control with skyhook and inertial delay control has been applied for modeling of the active suspension system with nonlinear parameters under the combination of three different random roads excitation, namely, class A, B and C. It is important to notice that the two objective functions which have been selected to be simultaneously optimized are, namely, vertical sprung mass acceleration and relative displacement between sprung mass and unsprung mass. The obtained results have been depicted in Pareto frontiers. Comparison of the results of this work with the ones in the literature has proved the superiority of methodology of this work. In fact, in 75% of outputs of application tests, the proposed design of this work has conquered the ones of previous works, and it shows the proper behavior of the suggested design of this work.

combinatorial choice models are based on the implicit assumption that decision-makers consider all possible combinations that can be made by the options in a given set. Therefore, these models assumed that the chosen combination is the most preferable combination. However, decision-makers may not consider all possible combinations due to the limited attention. Thus, the chosen combination is not necessarily the best. This paper presents a model that can explain such choice behaviors. After presenting the model, we investigate its revealed preference implications and explain how one can make inferences about individuals’,preferences considering their choices in the new context. Finally, for the model to be testable, we present its characterizing axiom and show that it is equivalent to the model.

Objective: Despite advances in revascularization therapy, coronary artery disease (CAD) poising a leading cause of morbidity and mortality risks worldwide, continues to challenge the medical community. This study aimed at examining the efficacy of bone marrow stem cells combination therapy used for cardiovascular regenerative therapies, and also to identify isolation procedure of autologous bone marrow stem cells (ABMSCs) might affect cell functionality and therapeutic efficacy, administrated through intra-myocardial and during coronary artery bypass graft (CABG).Materials and Methods: The Yazd Cardiovascular research center was investigating to establish a xeno-free protocol with lees processing steps for cell therapy and treatment of cardiovascular disease. After thoughtful consideration of both statistical and clinical principles, we recruited 15 patients to receive either combinations of ABMSCs or placebo. The overall baseline age of the patients was 60+9 years, and due to severe ischemic cardiomyopathy, need to have coronary bypass surgery. Each patient received a median of 5×107±1×107 ABMSC combinations harvested by the special procedure or an equal volume of diluent (placebo). Changes in left ventricular ejection fraction from baseline and wall motion, examined by magnetic resonance imaging and by echocardiography, respectively.Results: ABMSC delivery was successful in all patients with no arrhythmias, no elevated cardiac enzymes or complications related to the delivery. Compared with the placebo-control group, the ABMSC group had significant changes in routine clinical and biochemical test values (p<0.05). Weekly angina frequency was significantly lower in the cell-injected group than in placebo group. Left ventricular ejection fraction, end-systolic volume and wall motion was found to be significantly improved in the ABMSC group compared to the placebo group over the follow-up period.Conclusion: The designed protocol should be considered as an alternative method of ABMSC application in clinical trial for improving blood flow and contractile function of the heart, and also to safely deliver large number of cells regardless of different stem cell processing steps and RBC or xeno-contamination. This study indicates that the beneficial effect of special way which we used for ABMSC transplantation, would be pronounced in CAD patients.

In this paper, we consider statistics on permutations of lengthn represented geometrically as bargraphs having the same number of horizontal steps. More precisely, we nd the joint distribution of the descent and up step statistics on the bargraph representations, thereby obtaining a new rened count of permutations of a given length. To do so, we consider the distribution of the parameters on permutations of a more general multiset of which Sn is a subset. In addition to nding an explicit formula for the joint distribution on this multiset, we provide counts for the total number of descents and up steps of all its members, supplying both algebraic and combinatorial proofs. Finally, we derive explicit expressions for the sign balance of these statistics, from which the comparable results on permutations follow as special cases.

This article is intended to be a survey on some combinatorial topics in group theory. The bibliography at the end is neither claimed to be exhaustive, nor is it necessarily connected with a reference in the text. I include it as I see it revolves around the concepts which are discussed in the text.

Intracytoplasmic sperm injection (ICSI) is one of the most successful techniques of Assisted Reproductive Technology (ART) and is mostly in use for the treatment of infertility with male factors. In this method, before injecting sperm into the intracytoplasmic of the oocyte, cumulus cells around the oocyte must be stripped to facilitate the injection process. To achieve this, both enzymatic and mechanical methods are used in embryological laboratories for denudation, which has major deficiencies, including the possibility of damaging the oocyte prior to the injection process. In this research, a microfluidic-based device is introduced for the separation of cumulus cells around the oocyte with minimum manual operations. The results prove high efficiency, and non-destructive denudation of the oocyte with the reduced amount of culture medium leads to the low-cost preparation process of oocytes. The process can also be integrated with ICSI chips under development and will be reported shortly.