On Backtracking in Real-time Heuristic Search

Real-time heuristic search algorithms are suitable for situated agents that need to make their decisions in constant time. Since the original work by Korf nearly two decades ago, numerous extensions have been suggested. One of the most intriguing extensions is the idea of backtracking wherein the agent decides to return to a previously visited state as opposed to moving forward greedily. This idea has been empirically shown to have a significant impact on various performance measures. The studies have been carried out in particular empirical testbeds with specific real-time search algorithms that use backtracking. Consequently, the extent to which the trends observed are characteristic of backtracking in general is unclear. In this paper, we present the first entirely theoretical study of backtracking in real-time heuristic search. In particular, we present upper bounds on the solution cost exponential and linear in a parameter regulating the amount of backtracking. The results hold for a wide class of real-time heuristic search algorithms that includes many existing algorithms as a small subclass

32nd Annual Report 2023 : Convention on Long-range Transboundary Air Pollution : International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems

The Integrated Monitoring Programme (ICP IM) is part of the effect-oriented activities under the 1979 Convention on Long-range Transboundary Air Pollution, which covers the region of the United Nations Economic Commission for Europe (UNECE). The main aim of ICP IM is to provide a framework to observe and understand the complex changes occurring in natural/semi natural ecosystems. This report summarizes the work carried out by the ICP IM Programme Centre and several collaborating institutes. The emphasis of the report is in the work done during the programme year 2022/2023 including:• A short summary of previous data assessments• A status report of the ICP IM activities, content of the IM database, and geographical coverage of the monitoring network• Brief summary of forthcoming publication on heavy metal concentrations trend analysis• Update on developing co-operation with eLTER• Proposed workplan for the next period• Report on IM participation in Canadian led mercury sampling• National Reports on ICP IM activitie

RCK Domain Model of Calcium Activation in BK Channels

Potassium ion channels are ubiquitously expressed from bacteria to mammals where they are involved in various processes ranging from the regulation of osmotic pressure in a single cell to the electrical response in muscle fibers to the generation of action potentials in neurons. The B K channel family (BK for Big K+ conductance) is an interesting subfamily of K+ channels responsive to both membrane voltage and intracellular calcium ion. The unique, high-affinity Ca2+ sensitivity of B K channels is critical to their physiological function in various cell types. The mechanism by which Ca2+ activates B K channel gating, however, is not well understood. Here we present a structure-based approach to the study of B K channels with the goal of providing a structural and functional model of the Ca2+-activation mechanism. Sequence analysis of BK channel C-terminal domains and domains from prokaryotic homologs reveals the conservation of unique positions defining a novel regulatory domain associated with K conduction, the R C K domain. Crystal structures of R C K domains from prokaryotic sources relate the conservation of sequence to the structure, assembly and function of these domains. W e propose a hypothetical model for the structure and function of the Cterminal domains of B K as a set of R C K domains that conduct the Ca -activation mechanism. The features and constraints predicted by the R C K domain model are tested by the electrophysiological assay of a variety of human B K constructs. The results support a domain structure and assembly consistent with the proposed model for the B K C-terminus. In addition, the results identify residues and regions involved in Ca + activation: the Ca2+-binding event and the transduction of the binding energy through protein conformational changes to the channel domain. The R C K domain model thus provides a framework for the study of Ca2+ activation in B K channels

Ecological study of the tidal segment of the James River encompassing Hog Point : 1977 final technical report

Section I: CONTENTS River Biota Studies at the VEPCO Surry Nuclear Power Station by R. A. Jordan, P. A. Goodwin, R. K. Carpenter, and C. E. Sutton Section Ila: Plant Entrainment of Ichthyoplankton at the VEPCO Nuclear Power Plant by J. V. Merriner, A. D. Estes, and R. K. Dias Section lIb: Thermal Plume Entrainment of Ichthyoplankton at VEPCO Nuclear Power Station by J. V. Merriner, A. D. Estes, and R. K. Dia

IPLIB (Image processing library) user's manual

IPLIB is a collection of HP FORTRAN 77 subroutines and functions that facilitate the use of a COMTAL image processing system driven by an HP-1000 computer. It is intended for programmers who want to use the HP 1000 to drive the COMTAL Vision One/20 system. It is assumed that the programmer knows HP 1000 FORTRAN 77 or at least one FORTRAN dialect. It is also assumed that the programmer has some familiarity with the COMTAL Vision One/20 system

Assessment of the NPP VIIRS RVS for the Thermal Emissive Bands Using the First Pitch Maneuver Observations

The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key sensor carried on Suomi NPP (National Polar-orbiting Partnership) satellite (http://npp.gsfc.nasa.gov/viirs.html) (launched in October 2011). VIIRS sensor design draws on heritage instruments including AVHRR, OLS, SeaWiFS and MODIS. It has on-board calibration components including a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB), a V-groove blackbody for the thermal emissive bands (TEB), and a space view (SV) port for background subtraction. These on-board calibrators are located at fixed scan angles. The VIIRS response versus scan angle (RVS) was characterized prelaunch in lab ambient conditions and is currently used to characterize the on-orbit response for all scan angles relative to the calibrator scan angle (SD for RSB and blackbody for TEB). Since the RVS is vitally important to the quality of calibrated radiance products, several independent studies were performed to analyze the prelaunch RVS measurement data. A spacecraft level pitch maneuver was scheduled during the first three months of intensive Cal/Val. The NPP pitch maneuver provided a rare opportunity for VIIRS to make observations of deep space over the entire range of scan angles, which can be used to characterize the TEB RVS. This study will provide our analysis of the pitch maneuver data and assessment of the derived TEB RVS. A comparison between the RVS determined by the pitch maneuver observations and prelaunch lab tests will be conducted for each band, detector, and half angle mirror (HAM) sid

Impact of genotypic errors with equal and unequal family contribution on accuracy of genomic prediction in aquaculture using simulation

Genotypic errors, conflict between recorded genotype and the true genotype, can lead to false or biased population genetic parameters. Here, the effect of genotypic errors on accuracy of genomic predictions and genomic relationship matrix are investigated using a simulation study based on population and genomic structure comparable to black tiger prawn, Penaeus monodon. Fifty full-sib families across five generations with phenotypic and genotypic information on 53 K SNPs were simulated. Ten replicates of different scenarios with three heritability estimates, equal and unequal family contributions were generated. Within each scenario, four SNP densities and three genotypic error rates in each SNP density were implemented. Results showed that family contribution did not have a substantial impact on accuracy of predictions across different datasets. In the absence of genotypic errors, 3 K SNP density was found to be efficient in estimating the accuracy, whilst increasing the SNP density from 3 to 20 K resulted in a marginal increase in accuracy of genomic predictions using the current population and genomic parameters. In addition, results showed that the presence of even 10% errors in a 10 and 20 K SNP panel might not have a severe impact on accuracy of predictions. However, below 10 K marker density, even a 5% error can result in lower accuracy of predictions