402 research outputs found
Interference Channel with a Half-Duplex Out-of-Band Relay
A Gaussian interference channel (IC) aided by a half-duplex relay is
considered, in which the relay receives and transmits in an orthogonal band
with respect to the IC. The system thus consists of two parallel channels, the
IC and the channel over which the relay is active, which is referred to as
Out-of-Band Relay Channel (OBRC). The OBRC is operated by separating a multiple
access phase from the sources to the relay and a broadcast phase from the relay
to the destinations. Conditions under which the optimal operation, in terms of
the sum-capacity, entails either signal relaying and/or interference forwarding
by the relay are identified. These conditions also assess the optimality of
either separable or non-separable transmission over the IC and OBRC.
Specifically, the optimality of signal relaying and separable coding is
established for scenarios where the relay-to-destination channels set the
performance bottleneck with respect to the source-to-relay channels on the
OBRC. Optimality of interference forwarding and non-separable operation is also
established in special cases.Comment: 5 pages, 5 figures, to appear in Proceedings of IEEE ISIT 201
Just Desert
In this paper I examine the relevance of moral desert with regards to compatibilist accounts of moral responsibility. I look at two types of moral desert: (1) desert with relation to an agent and a moral community and (2) desert with relation to the moral worth of an agent or action. I begin by discussing Pereboom’s four cases and the problem that might arise for compatibilists given which view of moral desert they affirm. From there I explicate these two opposing conceptions of desert relevant to moral responsibility. I look at one example of the latter kind of desert: desert-as-merit. Then I examine two examples of the first kind of desert: desert-as-fit and desert-as-fairness. By showing the problems that arise for these two types of desert, I hope to weaken the compatibilist account
Performance Evaluation of Multiterminal Backhaul Compression for Cloud Radio Access Networks
In cloud radio access networks (C-RANs), the baseband processing of the
available macro- or pico/femto-base stations (BSs) is migrated to control
units, each of which manages a subset of BS antennas. The centralized
information processing at the control units enables effective interference
management. The main roadblock to the implementation of C-RANs hinges on the
effective integration of the radio units, i.e., the BSs, with the backhaul
network. This work first reviews in a unified way recent results on the
application of advanced multiterminal, as opposed to standard point-to-point,
backhaul compression techniques. The gains provided by multiterminal backhaul
compression are then confirmed via extensive simulations based on standard
cellular models. As an example, it is observed that multiterminal compression
strategies provide performance gains of more than 60% for both the uplink and
the downlink in terms of the cell-edge throughput.Comment: A shorter version of the paper has been submitted to CISS 201
Ultra-Reliable Cloud Mobile Computing with Service Composition and Superposition Coding
An emerging requirement for 5G systems is the ability to provide wireless
ultra-reliable communication (URC) services with close-to-full availability for
cloud-based applications. Among such applications, a prominent role is expected
to be played by mobile cloud computing (MCC), that is, by the offloading of
computationally intensive tasks from mobile devices to the cloud. MCC allows
battery-limited devices to run sophisticated applications, such as for gaming
or for the "tactile" internet. This paper proposes to apply the framework of
reliable service composition to the problem of optimal task offloading in MCC
over fading channels, with the aim of providing layered, or composable,
services at differentiated reliability levels. Inter-layer optimization
problems, encompassing offloading decisions and communication resources, are
formulated and addressed by means of successive convex approximation methods.
The numerical results demonstrate the energy savings that can be obtained by a
joint allocation of computing and communication resources, as well as the
advantages of layered coding at the physical layer and the impact of channel
conditions on the offloading decisions.Comment: 8 pages, 5 figures, To be presented at CISS 201
Prevention of medication related osteonecrosis of the jaw after dentoalveolar surgery : an institution's experience
Dentoalveolar surgery is a predisposing factor for medication related osteonecrosis of the jaw (MRONJ). The aim of our study was to evaluate the described surgical procedures to prevent the development of MRONJ after dentoalveolar surgery in patients receiving bisphosphonates. In this retrospective study, sixty-three dentoalveolar surgeries were performed on 44 patients taking bisphosphonate in accordance with the treatment procedures we described. The following procedures were applied to patients 1) use of antibiotics 2) performed dentoalveolar surgical procedures 3) fill the socket with leukocyte- and platelet-rich fibrin (L-PRF) 4) post-operative application of low level laser therapy through Nd: YAG laser 5) sutures were removed on post-op 14th day 6) long-term results were evaluated. Healing of all patients was uneventful. Complete mucosal healing was achieved in all patients at 1 month. There is no failure was observed in long-term follow-up. Because of the pathophysiology of MRONJ is not fully understood and has many risk factors, definitive protocols on prevention and treatment have not been established yet. Personal risk assessment is required for the prevention and treatment of MRONJ. The described surgical protocol may be considered to reduce the risk of developing MRONJ after dentoalveolar surgery due to its high success rate
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