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In this paper the conventional circular patch has been reshaped by two circular arcs with the FR4 Epoxy material for substrate. This is supported by the mathematical calculations of resonant frequencies with the help of Bressels function. The proposed antenna has been designed and simulated using Ansys HFSS version 15 software. The modifications which are implemented on the conventional circular patch leads to a unique geometry having two arcs separated by a certain distance. Here an optimized distance, equal to the free space wavelength λ 0 has been taken into account. An optimized circular slot is also implemented to enhance the bandwidth. The simulated and the measured results of the parameters like S 11 , VSWR have been compared. The results for the antenna gain, directivity, radiation efficiency also included in this paper. 15 GHz design frequency has been chosen as it is allocated for the 5G communication.

This article introduces a hybrid architecture of cryptography and coding technique to provide security in 5G communication networks. There are various types of attacks in 5G communication systems. Apart from contemporary attacks, we refer some of the peculiar attacks including DOS, DDOS, bot attack, Mantis Botnet, Mirai Botnet etc. These attacks jeopardize the security systems. To overcome the situation, we propose an architecture, which makes use of modified DES encryption followed by Hamming code. In transmitter section, the 256-bit input data is encrypted by 224-bit cipher key, which is then encoded with Hamming code (448, 256) to produce 448-bit of encrypted data. The reverse scheme is applicable in receiver section. We have used Xilinx software to simulate the proposed model. Simulation results show that the duration of both the encryption and encoding are in nano seconds. The intruders shall get very less time to interfere. Therefore, the proposed architecture shall improve the security in current 5G communication systems.

We study a model of voting with two alternatives in a symmetric environment. We characterize the interim allocation probabilities that can be implemented by a symmetric voting rule. We show that every such interim allocation probability can be implemented as a convex combination of two families of deterministic voting rules: qualified majority and qualified anti-majority. We also provide analogous results by requiring implementation by a symmetric monotone (strategy-proof) voting rule and by a symmetric unanimous voting rule. We apply our results to show that an ex ante Rawlsian rule is a convex combination of a pair of qualified majority rules.

We explore the consequences of weakening the notion of incentive compatibility from strategy-proofness to ordinal Bayesian incentive compatibility (OBIC) in the random assignment model. If the common prior of the agents is the uniform prior, then a large class of random mechanisms are OBIC with respect to this prior—this includes the probabilistic serial mechanism. We then introduce a robust version of OBIC: a mechanism is locally robust OBIC if it is OBIC with respect all independent and identical priors in some neighborhood of a given independent and identical prior. We show that every locally robust OBIC mechanism satisfying a mild property called elementary monotonicity is strategy-proof. This leads to a strengthening of the impossibility result in Bogomolnaia and Moulin (J Econ Theory 100:295–328, 2001): if there are at least four agents, there is no locally robust OBIC and ordinally efficient mechanism satisfying equal treatment of equals.

We study dominant strategy incentive compatibility in a mechanism design setting with contingent contracts where the payoff of each agent is observed by the principal and can be contracted upon. Our main focus is on the class of linear contracts (one of the most commonly used contingent contracts) which consist of a transfer and a flat rate of profit sharing. We characterize outcomes implementable by linear contracts and provide a foundation for them by showing that, in finite type spaces, every social choice function that can be implemented using a more general nonlinear contingent contract can also be implemented using a linear contract. We then qualitatively describe the set of implementable outcomes. We show that a general class of social welfare criteria can be implemented. This class contains social choice functions (such as the Rawlsian) which cannot be implemented using (uncontingent) transfers. Under additional conditions, we show that only social choice functions in this class are implementable.

Dexamethasone as an adjuvant to bupivacaine for supraclavicular brachial plexus (SCBP) block prolongs motor and sensory blockade. However, the effect of dexamethasone (8 mg) when added to levobupivacaine has not been well studied. This study was conducted to find out analgesic efficacy of dexamethasone as adjuvant to levobupivacaine in SCBP block. Ultrasound- guided SCBP block was given to sixty patients, randomly assigned into two groups. Group S (thirty patients) received 2 mL normal saline with 25 mL levobupivacaine (0.5%) and Group D (thirty patients) received 2 mL of dexamethasone (8 mg) with 25 mL of levobupivacaine (0.5%), respectively. Time for the first rescue analgesia, number of rescue analgesics required in 24 h and different block characteristics was assessed. Chi-square test and Student's -test were used for statistical analysis. Time for request of the first rescue analgesia was 396.13 ± 109.42 min in Group S and 705.80 ± 121.46 min in Group D ( < 0.001). The requirement for rescue analgesics was more in Group S when compared to Group D. The onset of sensory and motor block was faster in Group D when compared to Group S. The mean duration of sensory and motor block was significantly longer in Group D than Group S. The addition of dexamethasone to levobupivacaine in SCBP blockade prolonged time for first rescue analgesia and reduced the requirement of rescue analgesics with faster onset and prolonged duration of sensory and motor block.

This paper studies a model of mechanism design with transfers where agents' preferences need not be quasilinear. In such a model, (1) we characterize dominant strategy incentive compatible mechanisms using a monotonicity property; (2) we establish a revenue uniqueness result: for every dominant strategy implementable allocation rule, there is a unique payment rule that can implement it; and (3) we show that every dominant strategy incentive compatible, individually rational, and revenue-maximizing mechanism must charge zero payment for the worst alternative (outside option). These results are applicable in a wide variety of problems (single object auction, multiple object auction, public good provision etc.) under suitable richness of type space. In particular, our results are applicable to two important type spaces: (a) type space containing an arbitrarily small perturbation of quasilinear type space and (b) type space containing all positive income effect preferences.

In the private values single object auction model, we construct a satisfactory mechanism—a dominant strategy incentive compatible and budget-balanced mechanism satisfying equal treatment of equals. Our mechanism allocates the object with positive probability to only those agents who have the highest value and satisfies ex-post individual rationality. This probability is at least $\\left( {1 - \\frac{{\\text{2}}}{n}} \\right)$, where n is the number of agents. Hence, our mechanism converges to efficiency at a linear rate as the number of agents grow. Our mechanism has a simple interpretation: a fixed allocation probability is allocated using a second-price Vickrey auction whose revenue is redistributed among all the agents in a simple way. We show that our mechanism maximizes utilitarian welfare among all satisfactory mechanisms that allocate the object only to the highest-valued agents.

We study mechanism design in quasi-linear private values environments when there are two alternatives. We show that under a mild range condition, every implementable allocation rule is a generalized utility function maximizer. In unbounded domains, if we replace our range condition by an independence condition, then every implementable allocation rule is an affine maximizer. Our results extend Roberts' affine maximizer theorem (Roberts, In: Laffont J-J (ed) The characterization of implementable choice rules, 1979) to the case of two alternatives.

Mechanism design is the study of designing procedures for interaction of strategic agents such that the designer's objective is achieved in an equilibrium. The main challenge in mechanism design is that strategic (i.e. utility maximizing) agents have private information not known to the designer. Multidimensional mechanism design deals with mechanism design when strategic agents have multidimensional information, i.e. private information consists of different components. This article briefly surveys the literature on mechanism design where monetary transfers are allowed and agents have multidimensional private information. It identifies some of the fundamental results in the literature and some interesting open research issues.