Molecular communication in fluid media: The additive inverse Gaussian noise channel

We consider molecular communication, with information conveyed in the time of release of molecules. The main contribution of this paper is the development of a theoretical foundation for such a communication system. Specifically, we develop the additive inverse Gaussian (IG) noise channel model: a channel in which the information is corrupted by noise with an inverse Gaussian distribution. We show that such a channel model is appropriate for molecular communication in fluid media - when propagation between transmitter and receiver is governed by Brownian motion and when there is positive drift from transmitter to receiver. Taking advantage of the available literature on the IG distribution, upper and lower bounds on channel capacity are developed, and a maximum likelihood receiver is derived. Theory and simulation results are presented which show that such a channel does not have a single quality measure analogous to signal-to-noise ratio in the AWGN channel. It is also shown that the use of multiple molecules leads to reduced error rate in a manner akin to diversity order in wireless communications. Finally, we discuss some open problems in molecular communications that arise from the IG system model.Comment: 28 pages, 8 figures. Submitted to IEEE Transactions on Information Theory. Corrects minor typos in the first versio

Data-efficient Neuroevolution with Kernel-Based Surrogate Models

Surrogate-assistance approaches have long been used in computationally expensive domains to improve the data-efficiency of optimization algorithms. Neuroevolution, however, has so far resisted the application of these techniques because it requires the surrogate model to make fitness predictions based on variable topologies, instead of a vector of parameters. Our main insight is that we can sidestep this problem by using kernel-based surrogate models, which require only the definition of a distance measure between individuals. Our second insight is that the well-established Neuroevolution of Augmenting Topologies (NEAT) algorithm provides a computationally efficient distance measure between dissimilar networks in the form of "compatibility distance", initially designed to maintain topological diversity. Combining these two ideas, we introduce a surrogate-assisted neuroevolution algorithm that combines NEAT and a surrogate model built using a compatibility distance kernel. We demonstrate the data-efficiency of this new algorithm on the low dimensional cart-pole swing-up problem, as well as the higher dimensional half-cheetah running task. In both tasks the surrogate-assisted variant achieves the same or better results with several times fewer function evaluations as the original NEAT.Comment: In GECCO 201

Harnessing Wisdom for Managing Watersheds: Honey Bee Perspective on Innovations, Institutions and Policies for Marginal Environments

Participatory approaches for watershed management are now considered essential for sustainable natural resources management and yet there is very little opportunity for intellectual participation by the people. This requires understanding of the local knowledge systems and their institutional context. In this paper, we provide an overview of the conceptual framework which can facilitate such participation. The full report being published separately includes case studies of farmers’ innovations in natural resources management.

Implementation of FPGA in the Design of Embedded Systems

The use of FPGAs (Field Programmable Gate Arrays) and configurable processors is an interesting new phenomenon in embedded development. FPGAs offer all of the features needed to implement most complex designs. Clock management is facilitated by on-chip PLL (phase-locked loop) or DLL (delay-locked loop) circuitry. Dedicated memory blocks can be configured as basic single-port RAMs, ROMs, FIFOs, or CAMs. Data processing, as embodied in the devices’ logic fabric, varies widely. The ability to link the FPGA with backplanes, high-speed buses, and memories is afforded by support for various single ended and differential I/O standards. Also found on today’s FPGAs are system-building resources such as high speed serial I/Os, arithmetic modules, embedded processors, and large amounts of memory. Here in our project we have tried to implement such powerful FPGAs in the design of possible embedded systems that can be designed, burned and deployed at the site of operation for handling of many kinds of applications. In our project we have basically dealt with two of such applications –one the prioritized traffic light controller and other a speech encrypting and decrypting system

An Optimal Harvesting Strategy of a Three Species Syn-ecosystem with Commensalism and Stochasticity

In this paper we have studied the stability of three typical species syn-ecosystem. The system comprises of one commensal S1 and two hosts S2 and S3 . Both S2 and S2 benefit S1 without getting themselves affected either positively or adversely. Further S2 is a commensal of S3 and S3 is a host of both S1 and S2. Limited resources have been considered for all the three species in this case. The model equations of the system constitute a set of three first order non-linear ordinary differential equations. The possible equilibrium points of the model are identified. We have also studied the local and global stabilities. We have analyzed the bionomic equilibrium and optimal harvesting strategy using Pontryagin’s maximum principle. We have investigated the inhabitant intensities of the fluctuations (variances) around the positive equilibrium due to noise and have investigated the stability. We have also checked the MATLAB numerical simulations for stability of the system

Development of a creep data base management system for engineering materials

A fully menu driven creep data base management system has been developed for various high temperature materials using the client /server (C/S) architecture with Sybase system. 10 as backend and power builder 4.0 as an inter-face. The relational data base constitutes of various classes of materials, their heat treatment, prior history and the related creep properties at different test condit-ions, in addition to the source process route and chemical composition details.Top-down approach has been adopted in designing the entity-relationship (E-R) model. The creep data is organized into the third normal form, and the entire system is divided into manageable modules. Coding for the system is done using Transact-SQL for data defin- ition, manipulation and control operations, and power script language for application development. This article briefly outlines the formulation of data base design, and the implemented E-R model, in addition , to the prese-ntation of various screen formats used for data entry and retrieval modules

Evaluation and Analysis of Customer Specific Distribution Reliability Indices

Reliability of electrical distribution network is significant in ensuring quality service for customers. Reliability indices based on load and sustained interruptions are used to evaluate the reliability of distribution network. In this paper, taking the data from a chosen area of electrical distribution network in A.P, the reliability indices are computed Keywords: Distribution system, reliability indices, sustained interruption indices, matlab

Peripheral blood and ovarian levels of sex steroids in the cyclic hamster

Changes in progesterone (P), testosterone (T), estrone (E1) and estradiol-17β (E2) in peripheral blood, ovary, corpora lutea (CL) and in the nonluteal portion of the ovary (NLO) were studied in the cyclic hamster by RIA. In addition, androstenedione (A) was measured, but only in serum. Serum P levels were the same on Days 1 (day of ovulation) and 2 at 0900 h (5 ng/ml), but declined markedly on Day 3 and on the morning of Day 4 (proestrus). After the LH surge on the afternoon of Day 4, serum and ovarian levels of P increased abruptly until 1900 h to 11-18 ng/ml and declined slowly thereafter. Peak T levels in both serum (209 pg/ml) and the ovary occurred between 1400-1500 h of Day 4, paralleling the rising P levels. However, T levels declined rapidly after 1600 h to undetectable levels by 1900 h, but there was a second peak of T by 2300 h in serum which was matched by the ovary. Serum levels of E1 and E2 began to rise on Day 2, reaching peak values by Day 4 between 1200 and 1400 h (41 pg/ml and 152 pg/ml, respectively). Peak ovarian concentrations of E1 and E2 were reached on Day 4 at 0900 h. These high levels were maintained up to 1600 h of Day 4 and declined rapidly thereafter. The serum levels of E1 were about one-third as high as E2 and were not as drastically affected on the evening of Day 4. Serum androstenedione ranged from 1-2 ng/ml, but changes throughout the cycle were not as striking as for the other steroids. However, increased levels of A were associated with decreased levels of estrogens and vice-versa. Therefore, the circulating levels of A probably reflect altered secretion rates of other steroids. Administration of 5 μ g LH on the evening of Day 4 (when all steroid levels are declining) caused significant increases in P and T but not E2. Hence, the refractory period of estrogen synthesis on the evening of Day 4 cannot be attributed to insufficient levels of LH during the preovulatory period