Measurements and physical-layer modelling of transmission loss for gas turbine engine sensor networks

The aim of this study is to extract a physical-layer wireless channel model from a set of channel measurements, in support of the wider, collaborative, WIDAGATE project to assess the potential of wireless sensor networks for the condition monitoring of gas turbine engines. The collaborative partners in WIDAGATE are Rolls-Royce, Selex and University College London. The resulting model is being incorporated into a complete system protocol stack as part of the wider project. The physical layer channel model incorporates interference [1] and noise in addition to signal transmission characteristics

A Potts model for the distortion transition in LaMnO3_3

The Jahn-Teller distortive transition of \lmo is described by a modified 3-state Potts model. The interactions between the three possible orbits depends both on the orbits and their relative orientation on the lattice. Values of the two exchange parameters which are chosen to give the correct low temperature phase and the correct value for the transition temperature are shown to be consistent with microscopy theory. The model predicts a first order transitions and also a value for the entropy above the transition in good agreement with experiment. The theory with the same parameters also predicts the temperature dependence of the order parameter of orbital ordering agreeing well with published experimental results. Finally, the type of the transition is shown to be close to one of the most disordered phases of the generalised Potts model. The short range order found experimentally above the transition is investigated by this model.Comment: 16 pages, 7 figures and no tables. Re-submitted to Phys. Rev.

OSU-AGRANI Bank Rural Deposit Mobilization Experiment

Three models of incentive mechanisms to mobilize rural bank deposits were experimented with between February 1, 1986 and April 30, 1986 in three branches in each of two regions in Bangladesh. One model, the Tangible Incentive Model, was designed to test tangible incentives given to depositors, in addition to the normal interest income, for opening a new account or adding to an existing account and maintaining in those accounts an additional deposit of Tk. 500 or more for at least 90 days. Prize bonds valued at one percent of the eligible deposit balance were given to the depositors. Another model, the Marketing Model, was designed to test the impact of cash incentives paid to two specially appointed Field Assistants in the branch for marketing of bank deposits. The Field Assistants were paid Tk. 150 per month for incidental expenses, and an incentive bonus of one percent of eligible deposits mobilized of Tk. 1000 or more, and 10 or more accounts opened or reactivated. The third model, Employee Incentive Model, was designed to test additional financial incentives given to existing branch staff beyond the benefits currently provided. The branch staff, except the Manager, received the same incentive bonus and at the same rate as the Field Assistants in the Marketing Model. Over 800 new accounts were opened or dormant accounts reactivated in the six branches through the experiment. Total deposits of Tk. 1.4 billion were mobilized by these accounts. These deposits ranged from one percent to over eight percent of the branch's existing deposit base. The increase in number of accounts ranged from over one-half of one percent to almost thirteen percent of the branch's existing number of accounts. The Tangible Incentive Model produced the most cost effective result in generating new deposits and deposit accounts at the lowest cost per taka or per account mobilized. This model clearly shows that rural deposits can be mobilized by direct incentives. The overall implication of the experiment is that banks can mobilize rural deposits if serious efforts are made to reach this objective with appropriate incentive schemes

Evaluating Maintainability Prejudices with a Large-Scale Study of Open-Source Projects

Exaggeration or context changes can render maintainability experience into prejudice. For example, JavaScript is often seen as least elegant language and hence of lowest maintainability. Such prejudice should not guide decisions without prior empirical validation. We formulated 10 hypotheses about maintainability based on prejudices and test them in a large set of open-source projects (6,897 GitHub repositories, 402 million lines, 5 programming languages). We operationalize maintainability with five static analysis metrics. We found that JavaScript code is not worse than other code, Java code shows higher maintainability than C# code and C code has longer methods than other code. The quality of interface documentation is better in Java code than in other code. Code developed by teams is not of higher and large code bases not of lower maintainability. Projects with high maintainability are not more popular or more often forked. Overall, most hypotheses are not supported by open-source data.Comment: 20 page

Optimal Sizing of Standalone PV-Wind Hybrid Energy System in Rural Area North Egypt

This paper studies the sizing of stand-alone renewable energy system applied in rural areas in the north of Egypt. The available renewable energy sources in these areas are investigated to be integrated to supply the different types of electrical loads. The quality and quantity of these sources over various weather and climate changes are studied to construct a robust energy system. The load demand in such areas is determined according to all activities require electrical energy. This study considers the different economic levels and technologies which affect the load demand value. The technique and economical indices required to obtain the optimal are investigated and applied in the various estimated cases. The genetic algorithm (GA) technique is applied to determine the size and number of photovoltaic panels and wind turbines. The obtained solution takes into account the loss of power supply probability and the minimization of system cost. This study presents an essential phase in the sustainable development of such rural areas

A WiFi-based Reliable Network Architecture for Rural Regions

WiFi is being considered as an attractive option in providing low cost Internet connectivity to rural areas, and thereby reducing Digital Divide with urban areas. Most of the WiFi-based Long Distance network architectures extend Internet to rural regions through a single gateway node which is connected to high speed Internet. If the gateway node fails in such single gateway-based rural networks, the entire network gets collapsed. In this paper, we propose a reliable and low-cost WiFi based rural network architecture using multi-gateway concept. The proposed network architecture also allows load balancing among the available gateways. In such multi-gateway architecture, the network recovers from gateway failure and reestablishes the ongoing communication within 2-4 seconds time. The simulation results in NS-2 validate the claims of the paperKeywords—Digital Divide, WiFi, WiFi based Long Distance Network