Strategies and payoffs in quantum minority games

Game theory is the mathematical framework for analyzing strategic interactions in conflict and competition situations. In recent years quantum game theory has earned the attention of physicists, and has emerged as a branch of quantum information theory [1]. With the aid of entanglement and linear superposition of strategies, quantum games are shown to yield signifcant advantage over their classical counterparts. In this paper we explore optimal and equilibrium solutions to quantum minority games. Initial states with different level of entanglement are investigated. Focus will be on 4 and 6 player games with some N-player generalizations.Comment: 5 pages, 6 figures; Proceedings of the International Conference on Advances in Quantum Theory, Volume 1327, AIP,(2011

CEO Childhood Socioeconomic Status and Corporate Social Responsibility

Chief Executive Officers (CEOs) have been an important focus in strategy research for the past decade. Prior literature has explored several different CEO demographics, such as education, social ties, social capital, power, and their impact on behavior. While preceding literature has linked CEO demographics to different behavioral aspects, the focus on CEO upbringing is rather rare. Surprisingly, no research has focused on CEO childhood and its impact on corporate social responsibility. This study examines how CEO socioeconomic status (SES) during developmental years (childhood to adulthood) impacts CSR. Drawing on theory from psychology I hypothesize that firms led by CEOs with humble upbringings will invest more in CSR than other firms and that this effect is strengthened when the CEO is narcissistic. I find support for my hypotheses within a dataset of Fortune 100 firms between 2000 and 2013

Resource Allocation in Vehicular Cloud Computing

Recently, we have witnessed the emergence of Cloud Computing, a paradigm shift adopted by information technology (IT) companies with a large installed infrastructure base that often goes under-utilized. The unmistakable appeal of cloud computing is that it provides scalable access to computing resources and to a multitude of IT services. Cloud computing and cloud IT services have seen and continue to see a phenomenal adoption rate around the world. Recently, Professor Olariu and his coworkers through series of research introduced a new concept, Vehicular Cloud Computing. A Vehicular Cloud (VC) is a network of vehicles in a parking lot that can provide computation services to users. In this model each vehicle is a computation node. Some of the applications of a VC include a datacenter at the airport, a data cloud in a parking lot, and a datacenter at the mall. The defining difference between vehicular and conventional clouds lies in the distributed ownership and, consequently, the unpredictable availability of computational resources. As cars enter and leave the parking lot, new computational resources become available while others depart, creating a dynamic environment where the task of efficiently assigning jobs to cars becomes very challenging. Our main contribution is a number of scheduling and fault-tolerant job assignment strategies, based on redundancy, that mitigate the effect of resource volatility in vehicular clouds. We offer a theoretical analysis of the expected job completion time in the case where cars do not leave during a checkpoint operation and also in the case where cars may leave while checkpointing is in progress, leading to system failure. A comprehensive set of simulations have shown that our theoretical predictions are accurate. We considered two different environments for scheduling strategy: deterministic and stochastic. In a deterministic environment the arrival and departure of cars are known. This scenario is for environments like universities where employees should be present at work with known schedules and the university rents out its employees\u27 cars as computation nodes to provide services as a vehicular cloud. We presented a scheduling model for a vehicular cloud based on mixed integer linear programming. This work investigates a job scheduling problem involving non-preemptive tasks with known processing time where job migration is allowed. Assigning a job to resources is valid if the job has been executed fully and continuously (no interruption). A job cannot be executed in parallel. In our approach, the determination of an optimal job schedule can be formulated as maximizing the utilization of VC and minimizing the number of job migrations. Utilization can be calculated as a time period that vehicles have been used as computation resources. For dynamic environment in terms of resource availability, we presented a stochastic model for job assignment. We proposed to make job assignment in VC fault tolerant by using a variant of the checkpointing strategy. Rather than saving the state of the computation, at regular times, the state of the computation is only recorded as needed. Also, since we do not assume a central server that stores checkpointed images, like conventional cloud providers do, in our strategy checkpointing is performed by a car and the resulting image is stored by the car itself. Once the car leaves, the image is lost. We consider two scenarios: in the first one, cars do not leave during checkpointing; in the second one, cars may leave during checkpointing, leading to system failure. Our main contribution is to offer theoretical predictions of the job execution time in both scenarios mentioned above. A comprehensive set of simulations have shown that our theoretical predictions are accurate

Development of an Instrumented and Powered Exoskeleton for the Rehabilitation of the Hand

With improvements in actuation technology and sensory systems, it is becoming increasingly feasible to create powered exoskeletal garments that can assist with the movement of human limbs. This class of robotics referred to as human-machine interfaces will one day be used for the rehabilitation of paralysed, damaged or weak upper and lower extremities. The focus of this project was the development of an exoskeletal interface for the rehabilitation of the hands. A novel sensor was designed for use in such a device. The sensor uses simple optical mechanisms centred on a spring to measure force and position simultaneously. In addition, the sensor introduces an elastic element between the actuator and its corresponding hand joint. This will allow series elastic actuation (SEA) to improve control and safely of the system. The Hand Rehabilitation Device requires multiple actuators. To stay within volume and weight constraints, it is therefore imperative to reduce the size, mass and efficiency of each actuator without losing power. A method was devised that allows small efficient actuating subunits to work together and produce a combined collective output. This work summation method was successfully implemented with Shape Memory Alloy (SMA) based actuators. The actuation, sensory, control system and human-machine interface concepts proposed were evaluated together using a single-joint electromechanical harness. This experimental setup was used with volunteer subjects to assess the potentials of a full-hand device to be used for therapy, assessment and function of the hand. The Rehabilitation Glove aims to bring significant new benefits for improving hand function, an important aspect of human independence. Furthermore, the developments in this project may one day be used for other parts of the body helping bring human-machine interface technology into the fields of rehabilitation and therapy

An Experimental Comparison of the Refrigerant Flow through Adiabatic and Non-Adiabatic Helical Capillary Tubes

Capillary tubes are used as refrigerant controlling devices, expansion devices and also as heart of a small vapor compression refrigeration cycle. It connects outlet condenser to the inlet evaporator and balances the refrigeration cycle pressure and controls the refrigerant mass flux. Capillary tubes are relatively cheap, resulting in extensive implementations in small household refrigerators and freezers with nearly constant refrigeration load. In general, the inner diameter and length of a capillary tube ranges are from 0.5-2.0 mm, and 2-6 m, respectively. In some vapor compression refrigeration cycle applications (VCRC), capillary tubes are coiled to minimize the space. The fluid flow in coiled capillary tubes is subjected to the centrifugal force which causes secondary flow effect. Some researchers have referred to Dean effect to describe this secondary flow. Dean Number is defined as De = Re (d/D)0.5 that affects the amount of heat transfer, momentum, and mass flux in both kinds of coiled tubes. Generally, in domestic refrigerators, the capillary tube and suction line is soldered to each other in order to increase the heat transfer between them, which results in increasing cooling capacity, and avoid the entering of liquid into the compressor. The refrigerant flow through capillary tube flow is notably affected by the heat transfer to the suction line. The adiabatic flow follows a path that is close to an isenthalpic line, whilst the non-adiabatic flow is projected toward the line of saturated liquid, increasing the amount of liquid in the two-phase mixture and decreasing the vapor quality at the evaporator inlet. As a consequence, the refrigerating effect in the evaporator is increased. This paper presents experimental study of refrigerant flow through helical non-adiabatic (diabatic) capillary tubes. This model is validated by previously published experimental data and also by test results performed and presented in this work for R-134a.The effect of capillary tube inner diameter, length, relative roughness and coil diameter, and also various test conditions such as inlet pressure, inlet temperature, and sub-cooling degree of refrigerants is investigated. Pressure distribution and temperature variation are obtained experimentally. Furthermore, main subject of this study is experimental investigation of diabatic helical capillary tubes. Therefore this experimental set up is used for investigation of metastable flow, re-condensation, choked and hysteresis phenomenon. The experimental results illustrated that critical ratio (Gc/Gs) is main parameters that affect metastable flow through coiled diabatic capillary tube. If mass flux in the coiled capillary tube (Gc) is constant, the rate of heat transfer from the capillary tube to the suction decreases with a decrease of the mass flux in the suction line (Gs). Therefore, an increase of the mass flux ratio represents a decrease of the heat transfer rate between the capillary tube and suction line. The results show that metastable flow in the diabatic coiled capillary tube with 1.397 mm inner diameter, 30 mm coil diameter,4360 mm length, 4 mm inner diameter of suction line, exists when the heat transfer rate between the coiled capillary tube and the suction line is weak with Gc/Gs\u3e343