Throughput Analysis for Wireless Networks with Full-Duplex Radios

This paper investigates the throughput for wireless network with full-duplex radios using stochastic geometry. Full-duplex (FD) radios can exchange data simultaneously with each other. On the other hand, the downside of FD transmission is that it will inevitably cause extra interference to the network compared to half-duplex (HD) transmission. In this paper, we focus on a wireless network of nodes with both HD and FD capabilities and derive and optimize the throughput in such a network. Our analytical result shows that if the network is adapting an ALOHA protocol, the maximal throughput is always achieved by scheduling all concurrently transmitting nodes to work in FD mode instead of a mixed FD/HD mode or HD mode regardless of the network configurations. Moreover, the throughput gain of using FD transmission over HD transmission is analytically lower and upper bounded.Comment: 4 figure

An atomistic investigation of nanometric cutting process using a multi-tip single crystal diamond tool

In recent years great efforts are being made for the design and fabrication of periodic nanostructures used in emerging nano-products, such as plasmonic lens, nano-grating and high density hard disk etc. In our previous research work, a deterministic fabrication approach to cost-effectively manufacturing nano gratings over large area has been developed through single point diamond turning by using a multi-tip nano-scale single crystal diamond tool fabricated by FIB (Focus Ion Beam). However, the machining mechanism and technical limits of this approach i.e. the minimum dimension of nanostructures that can be obtained has not known yet. Due to the limitation of real-time detect equipment as well as the high research cost, it is difficult to obtain a quick answer through experimental work. On the other hand molecular dynamics (MD) simulation provides a cost-effective solution for this problem. Based on the merit offered by the large-scale molecular dynamics simulation method and new progresses made in high performance computing (HPC) technique, this paper proposes a new MD model for nanometric cutting process using a multi-tip single crystal diamond (SCD) tools to machine single crystal copper workpieces. By using centrosymmetry parameter (CSP) method and combining it with the dislocation nucleation and propagation theory, the machining mechanism and generation of nanostructures are studied through MD simulation. In order to reveal the dependence of the depth of cut on the integrality of generated nanostructures, a number of MD simulations have been carried out under depth of cut varying from 0.5, 1.0, 1.5, 2.0, and 3.0nm. The simulation results show that the depth of cut has significant influence on the integrality of the machined nanostructured surfaces and cutting force. A concept of maximum depth of cut to obtain high precision nanostructured surfaces in a single cutting pass is proposed based on analysis of the dimensional accuracy of the integrality machined nanostructures. In all simulations the cutting forces fluctuate around a constant value after chip formation

Systems of interacting diffusions with partial annihilation through membranes

We introduce an interacting particle system in which two families of reflected diffusions interact in a singular manner near a deterministic interface $I$. This system can be used to model the transport of positive and negative charges in a solar cell or the population dynamics of two segregated species under competition. A related interacting random walk model with discrete state spaces has recently been introduced and studied in Chen and Fan (2014). In this paper, we establish the functional law of large numbers for this new system, thereby extending the hydrodynamic limit in Chen and Fan (2014) to reflected diffusions in domains with mixed-type boundary conditions, which include absorption (harvest of electric charges). We employ a new and direct approach that avoids going through the delicate BBGKY hierarchy.Comment: Published at http://dx.doi.org/10.1214/15-AOP1047 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Aryl Hydrocarbon Receptor-Mediated Induction of CYP1A1 and CYP1B1 Enzymes in Brain: A Preliminary Exploration of the Role of Oxylipins in Lung Cancer Metastasis to Brain

Lung cancer is one of the most frequent diagnosis cancers in the U.S. Importantly, primary lung cancer frequently metastasizes to brain, but the survival and treatment of lung cancer brain metastasis are both poor. Aryl Hydrocarbon Receptor (AHR) mediated induction of Cytochrome P450 enzymes has been linked to cancer progression via binding to AHR agonists like 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). The exposure of TCDD significantly increases CYP 1A1 and CYP 1B1 in the lung and liver. The western diet typically contains a high ratio of omega-6 (-6) to omega-3 (-3) polyunsaturated fatty acids (PUFA). Recently, our group has demonstrated that the action of -6 and -3 PUFA metabolism on tumor progression is an AHR dependent process. TCDD promotes tumor growth and metastasis under -6 enriched diets but inhibits tumor growth and metastasis under -3 enriched diets. This finding indicates that TCDD impact on lung cancer progression can be modified by dietary PUFA. Based on this new research ground, it is also interesting to evaluate TCDD’s action on primary lung cancer metastasis to the brain depending on different ratio of -6 to -3 PUFA in diet. We hypothesized that the lung tumor increases the metastasis to the brain through, an AHR agonist like TCDD, which induce the expression of some cytochrome P450 in the brain of the mice that were fed with rich-⍵6 diet. To evaluate our hypothesis, we performed immunohistochemistry, digital pathology, RT-PCR, and liquid chromatography with tandem mass spectrometry. Our data demonstrated that the brain metastasis was found in mice fed with rich- ω-6 diet in mice treated with TCDD as compared with untreated mice. Further, TCDD significantly induced CYP 1A1 and CYP 1B1 in mice brain tissue under ω-6 enriched diet. In addition, the levels of oxylipins in plasma demonstrated that epoxides 5,6 EET are increases after TCCD treatment, as well as various diols like 5,6-DiHETrE, 11,12-DiHETrE, and 14,15-DiHETrE.These results provide us a future research direction on combining effects of diets and environment carcinogens to analyze the mechanism to be involved in the metastasis to the brain from the lung tumor cells

Investigation of the shape transferability of nanoscale multi-tip diamond tools in the diamond turning of nanostructures

In this article, the shape transferability of using nanoscale multi-tip diamond tools in the diamond turning for scale-up manufacturing of nanostructures has been demonstrated. Atomistic multi-tip diamond tool models were built with different tool geometries in terms of the difference in the tip cross-sectional shape, tip angle, and the feature of tool tip configuration, to determine their effect on the applied forces and the machined nano-groove geometries. The quality of machined nanostructures was characterized by the thickness of the deformed layers and the dimensional accuracy achieved. Simulation results show that diamond turning using nanoscale multi-tip tools offers tremendous shape transferability in machining nanostructures. Both periodic and non-periodic nano-grooves with different cross-sectional shapes can be successfully fabricated using the multi-tip tools. A hypothesis of minimum designed ratio of tool tip distance to tip base width (L/Wf) of the nanoscale multi-tip diamond tool for the high precision machining of nanostructures was proposed based on the analytical study of the quality of the nanostructures fabricated using different types of the multi-tip tools. Nanometric cutting trials using nanoscale multi-tip diamond tools (different in L/Wf) fabricated by focused ion beam (FIB) were then conducted to verify the hypothesis. The investigations done in this work imply the potential of using the nanoscale multi-tip diamond tool for the deterministic fabrication of period and non-periodic nanostructures, which opens up the feasibility of using the process as a versatile manufacturing technique in nanotechnology