Joint TAS and power allocation for D2D cooperative networks

The outage probability (OP) performance of transmit antenna selection (TAS) in decode-and-forward (DF) relaying device-to-device (D2D) networks over N-Nakagami fading channels is investigated in this paper. Exact closed-form expressions for the OP of two TAS schemes are derived. The power allocation problem is formulated to determine how the transmit power should be divided between the broadcast and relay phases to optimize performance. The OP performance under different conditions is evaluated through numerical simulation to verify the analysis. These results show that the optimal TAS scheme provides better OP performance than the suboptimal scheme, but the performance gap is reduced as the number of antennas at the source is increased. The fading coefficient, number of cascaded components, relative geometrical gain, power allocation parameter, and number of transmit antennas are shown to have a significant influence on the OP performance.     

Two-Way Interconnection with Partial Consumer Participation

This paper incorporates partial consumer participation in a model of competition between telecommunications networks with two-way interconnection. It is shown, in contrast to the results of similar models with full participation, that the firms' equilibrium profits depend on the level of a reciprocal access charge under two-part retail pricing. Under some simplifying assumptions, it is shown that firms prefer the access charge be set equal to the marginal cost of termination, which coincides with the social optimum. Without these additional assumptions the model is analytically complex and simulation results are presented that suggest firms prefer the access charge to be less than marginal cost, while the socially optimal access charge may be above or below cost depending on the differentiation of the firms.     

Closed-loop drip irrigation control using a hybrid wireless sensor and actuator network

In this research, a closed-loop drip irrigation control hybrid wireless sensor and actuator network (HWSAN) prototype were developed and deployed in a crop field for soil property precise measurement and precision irrigation in accordance with the measured soil property. The HWSAN was composed of a wireless sensor and actuator network (WSAN) used for in-field soil property monitoring and irrigation control and a laboratory supervising system. The WSAN included ten sensor nodes, five irrigation control nodes...     

Remote sensing of vegetation and land-cover change in Arctic Tundra Ecosystems

The objective of this paper is to review research conducted over the past decade on the application of multi-temporal remote sensing for monitoring changes of Arctic tundra lands. Emphasis is placed on results from the National Science Foundation Land-Air-Ice Interactions (LAII) program and on optical remote sensing techniques. Case studies demonstrate that ground-level sensors on stationary or moving track platforms and wide-swath imaging sensors on polar orbiting satellites are particularly useful for capturing optical remote sensing data at sufficient frequency to study tundra vegetation dynamics and changes for the cloud prone Arctic. Less frequent imaging with high spatial resolution instruments on aircraft and lower orbiting satellites enable more detailed analyses of land cover change and calibration/validation of coarser resolution observations.The strongest signals of ecosystem change detected thus far appear to correspond to expansion of tundra shrubs and changes in the amount and extent of thaw lakes and ponds. Changes in shrub cover and extent have been documented by modern repeat imaging that matches archived historical aerial photography. NOAA Advanced Very High Resolution Radiometer (AVHRR) time series provide a 20-year record for determining changes in greenness that relates to photosynthetic activity, net primary production, and growing season length. The strong contrast between land materials and surface waters enables changes in lake and pond extent to be readily measured and monitored.     

Mood modeling: accuracy depends on active logging and reflection

Current behavior change systems often demand extremely advanced sensemaking skills, requiring users to interpret personal datasets in order to understand and change behavior. We describe EmotiCal, a system to help people better manage their emotions, that finesses such complex sensemaking by directly recommending specific mood-boosting behaviors to users. This paper first describes how we develop the accurate mood models that underlie these mood-boosting recommendations. We go on to analyze what types of information contribute most to the predictive power of such models, and how we might design systems to reliably collect such predictive information. Our results show that we can derive very accurate mood models with relatively small samples of just 70 users. These models explain 61% of variance by combining: (a) user reflection about the effects of different activities on mood, (b) user explanations of how different activities affect mood, and (c) individual differences. We discuss the implications of these findings for the design of behavior change systems, as well as for theory and practice. Contrary to many recent approaches, our findings argue for the importance of active user reflection rather than passive sensing.     

The Coolest Way to Generate Binary Strings

Pick a binary string of length n and remove its first bit b. Now insert b after the first remaining 10, or insert $\overline{b}$ at the end if there is no remaining 10. Do it again. And again. Keep going! Eventually, you will cycle through all 2 ⁿ of the binary strings of length n. For example, are the binary strings of length n=4, where and . And if you only want strings with weight (number of 1s) between ? and u? Just insert b instead of $\overline{b}$ when the result would have too many 1s or too few 1s. For example, are the strings with n=4, ?=0 and u=2. This generalizes ‘cool-lex’ order by Ruskey and Williams (The coolest way to generate combinations, Discrete Mathematics) and we present two applications of our ‘cooler’ order. First, we give a loopless algorithm for generating binary strings with any weight range in which successive strings have Levenshtein distance two. Second, we construct de Bruijn sequences for (i) ?=0 and any u (maximum specified weight), (ii) any ? and u=n (minimum specified weight), and (iii) odd u?? (even size weight range). For example, all binary strings with n=6, ?=1, and u=4 appear once (cyclically) in . We also investigate the recursive structure of our order and show that it shares certain sublist properties with lexicographic order.     

The Flexible Rare Event Sampling Harness System (FRESHS)

We present the software package FRESHS (http://www.freshs.org) for parallel simulation of rare events using sampling techniques from the ‘splitting’ family of methods. Initially, Forward Flux Sampling (FFS) and Stochastic Process Rare Event Sampling (SPRES) have been implemented. These two methods together make rare event sampling available for both quasi-static and full non-equilibrium regimes. Our framework provides a plugin system for software implementing the underlying physics of the system of interest. At present, example plugins exist for our framework to steer the popular MD packages GROMACS, LAMMPS and ESPResSo, but due to the simple interface of our plugin system, it is also easy to attach other simulation software or self-written code. Use of our framework does not require recompilation of the simulation program. The modular structure allows the flexible implementation of further sampling methods or physics engines and creates a basis for objective comparison of different sampling algorithms.     

Overview or "underview"? Comment on Satz and Fletcher's "Emergent trends in neuropsychology: An overview."

Argues that P. Satz and J. M. Fletcher (see record 1982-05864-001) ignored research contradicting their dismissal of evidence of the greater plasticity and recovery from damage of the infant than adult brain as "myths." It is also argued that their overview also failed to consider critical complications that may limit or reverse patterns of recovery and overlooked accumulating evidence of principles not only underlying the pathogenic mechanism in earlier or later disorganizations of cerebral functions and principles of their organization but especially their reorganization following brain insults in infants and adults. (56 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of boron in boron fibres

The structure of noncrystalline, chemically vapour-deposited boron fibres was investigated by computer modelling the experimentally obtained X-ray diffraction patterns. The diffraction patterns from the models were computed using the Debye scattering equation. The modelling was done utilizing the minimum nearest-neighbour distance, the density of the model, and the broadening and relative intensity of the various peaks as boundary conditions. The results suggest that the fibres consist of a continuous network of randomly oriented regions of local atomic order, about 2 nm in diameter, containing boron atoms arranged in icosahedra. Approximately half of these regions have a tetragonal structure and the remaining half a distorted rhombohedral structure. The model also indicates the presence of many partial icosahedra and loose atoms not associated with any icosahedra. The partial icosahedra and loose atoms indicated in the present model are in agreement with the relaxing sub-units which have been suggested to explain the anelastic behaviour of fibre boron and the loosely bound boron atoms which have been postulated to explain the strengthening mechanism in boron fibres during thermal treatment.