Privacy Games: Optimal User-Centric Data Obfuscation

In this paper, we design user-centric obfuscation mechanisms that impose the minimum utility loss for guaranteeing user's privacy. We optimize utility subject to a joint guarantee of differential privacy (indistinguishability) and distortion privacy (inference error). This double shield of protection limits the information leakage through obfuscation mechanism as well as the posterior inference. We show that the privacy achieved through joint differential-distortion mechanisms against optimal attacks is as large as the maximum privacy that can be achieved by either of these mechanisms separately. Their utility cost is also not larger than what either of the differential or distortion mechanisms imposes. We model the optimization problem as a leader-follower game between the designer of obfuscation mechanism and the potential adversary, and design adaptive mechanisms that anticipate and protect against optimal inference algorithms. Thus, the obfuscation mechanism is optimal against any inference algorithm

Reducing the delivery lead time in a food distribution SME through the implementation of six sigma methodology

Purpose – Six sigma is a systematic data driven approach to reduce the defect and improve the quality in any type of business. The purpose of this paper is to present the findings from the application of six sigma in a food service “small to medium sized enterprise” (SME) in a lean environment to reduce the waste in this field. Design/methodology/approach – A simplified version of six sigma is adopted through the application of appropriate statistical tools in order to focus on customer's requirements to identify the defect, the cause of the defect and improve the delivery process by implementing the optimum solution. Findings – The result suggests that modification in layout utilization reduced the number of causes of defect by 40 percent resulting in jumping from 1.44 sigma level to 2.09 Sigma level which is substantial improvement in SME. Research limitations/implications – Simplicity of six sigma is important to enabling any SME to identify the problem and minimize its cause through a systematic approach. Practical implications – Integrating of supply chain objectives with any quality initiatives such as lean and six sigma has a substantial effect on achieving to the targets. Originality/value – This paper represents a potential area in which six sigma methodology along side the lean management can promote supply chain management objectives for a food distribution SME

Millimeter Wave Ad Hoc Networks: Noise-limited or Interference-limited?

In millimeter wave (mmWave) communication systems, narrow beam operations overcome severe channel attenuations, reduce multiuser interference, and thus introduce the new concept of noise-limited mmWave wireless networks. The regime of the network, whether noise-limited or interference-limited, heavily reflects on the medium access control (MAC) layer throughput and on proper resource allocation and interference management strategies. Yet, alternating presence of these regimes and, more importantly, their dependence on the mmWave design parameters are ignored in the current approaches to mmWave MAC layer design, with the potential disastrous consequences on the throughput/delay performance. In this paper, tractable closed-form expressions for collision probability and MAC layer throughput of mmWave networks, operating under slotted ALOHA and TDMA, are derived. The new analysis reveals that mmWave networks may exhibit a non-negligible transitional behavior from a noise-limited regime to an interference-limited regime, depending on the density of the transmitters, density and size of obstacles, transmission probability, beamwidth, and transmit power. It is concluded that a new framework of adaptive hybrid resource allocation procedure, containing a proactive contention-based phase followed by a reactive contention-free one with dynamic phase durations, is necessary to cope with such transitional behavior.Comment: accepted in IEEE GLOBECOM'1