Reconsiderations on the Equivalence of Convergence between Mann and Ishikawa Iterations for Asymptotically Pseudocontractive Mappings

Our aim in this paper is to illustrate that the proof of main theorem of Rhoades and Şoltuz (2003) concerning the equivalence between the convergences of Ishikawa and Mann iterations for uniformly L-Lipschitzian asymptotically pseudocontractive maps is incorrect and to provide its correct version

Auto Search Indexer for End-to-End Document Retrieval

Generative retrieval, which is a new advanced paradigm for document retrieval, has recently attracted research interests, since it encodes all documents into the model and directly generates the retrieved documents. However, its power is still underutilized since it heavily relies on the "preprocessed" document identifiers (docids), thus limiting its retrieval performance and ability to retrieve new documents. In this paper, we propose a novel fully end-to-end retrieval paradigm. It can not only end-to-end learn the best docids for existing and new documents automatically via a semantic indexing module, but also perform end-to-end document retrieval via an encoder-decoder-based generative model, namely Auto Search Indexer (ASI). Besides, we design a reparameterization mechanism to combine the above two modules into a joint optimization framework. Extensive experimental results demonstrate the superiority of our model over advanced baselines on both public and industrial datasets and also verify the ability to deal with new documents.Comment: EMNLP 202

Calibrating LLM-Based Evaluator

Recent advancements in large language models (LLMs) on language modeling and emergent capabilities make them a promising reference-free evaluator of natural language generation quality, and a competent alternative to human evaluation. However, hindered by the closed-source or high computational demand to host and tune, there is a lack of practice to further calibrate an off-the-shelf LLM-based evaluator towards better human alignment. In this work, we propose AutoCalibrate, a multi-stage, gradient-free approach to automatically calibrate and align an LLM-based evaluator toward human preference. Instead of explicitly modeling human preferences, we first implicitly encompass them within a set of human labels. Then, an initial set of scoring criteria is drafted by the language model itself, leveraging in-context learning on different few-shot examples. To further calibrate this set of criteria, we select the best performers and re-draft them with self-refinement. Our experiments on multiple text quality evaluation datasets illustrate a significant improvement in correlation with expert evaluation through calibration. Our comprehensive qualitative analysis conveys insightful intuitions and observations on the essence of effective scoring criteria.Comment: 22 pages,11 figure

Investigation on physical activation of some Mongolian coals

Activation characteristics of four different Mongolian coals were investigated. The coals were carbonized at temperatures of 550 °C and the obtained samples were activated by preheated steam. The pore size, pore volume and surface areas of all activated carbons (AC) have been determined by adsorption of nitrogen (N2) gas. The BET surface areas of Aduunchuluun (ACAC), Shivee Ovoo (SCAC), Baganuur (BCAC) coal and Ulaan Ovoo coals (UCAC) are 283, 205, 251 and 460 m2/g respectively. Langmuir surface area is 283 m2/g of ACAC, 230 m2/g of SCAC, 537 m2/g in UCAC and 254 m2/g in BCAC

Genome Sequence of the Versatile Fish Pathogen Edwardsiella tarda Provides Insights into its Adaptation to Broad Host Ranges and Intracellular Niches

BACKGROUND:Edwardsiella tarda is the etiologic agent of edwardsiellosis, a devastating fish disease prevailing in worldwide aquaculture industries. Here we describe the complete genome of E. tarda, EIB202, a highly virulent and multi-drug resistant isolate in China. METHODOLOGY/PRINCIPAL FINDINGS:E. tarda EIB202 possesses a single chromosome of 3,760,463 base pairs containing 3,486 predicted protein coding sequences, 8 ribosomal rRNA operons, and 95 tRNA genes, and a 43,703 bp conjugative plasmid harboring multi-drug resistant determinants and encoding type IV A secretion system components. We identified a full spectrum of genetic properties related to its genome plasticity such as repeated sequences, insertion sequences, phage-like proteins, integrases, recombinases and genomic islands. In addition, analysis also indicated that a substantial proportion of the E. tarda genome might be devoted to the growth and survival under diverse conditions including intracellular niches, with a large number of aerobic or anaerobic respiration-associated proteins, signal transduction proteins as well as proteins involved in various stress adaptations. A pool of genes for secretion systems, pili formation, nonfimbrial adhesions, invasions and hemagglutinins, chondroitinases, hemolysins, iron scavenging systems as well as the incomplete flagellar biogenesis might feature its surface structures and pathogenesis in a fish body. CONCLUSION/SIGNIFICANCE:Genomic analysis of the bacterium offered insights into the phylogeny, metabolism, drug-resistance, stress adaptation, and virulence characteristics of this versatile pathogen, which constitutes an important first step in understanding the pathogenesis of E. tarda to facilitate construction of a practical effective vaccine used for combating fish edwardsiellosis

Numerical simulation of canopy flow and carbon dioxide flux at the west coast flux station

Using an eddy covariance-approach to estimate net-ecosystem-exchange (NEE) of carbon dioxide (CO₂) requires that advection is negligible. This approach assumes flat and homogenous terrain. Sloping and heterogeneous topography may contribute to errors in estimating carbon sequestration or loss of an ecosystem. The complex topography at the West Coast Flux station on Vancouver Island raises uncertainties on the estimation of NEE. This research employs a high-resolution atmospheric model to study the effects of a deep forest canopy on atmospheric boundary-layer flow, and to evaluate the roles of mesoscale flow and the advection effects on NEE estimates. The model is refined to include tree-drag, radiation effects of canopy on surface energy budget, CO₂ budget and soil conduction. Over an idealized two-dimensional mountain of similar horizontal and vertical scales as Vancouver Island, the numerical simulations capture the first-order effects of diurnal heating/cooling on the sloping terrain during fair-weather. The volume exchange of heat, momentum and CO₂ above and within the canopy appears to be strongly affected by the local flows resulting from diurnal thermal forcing, land/sea breezes and convective thermals. Synoptic-scale forcing is neglected. The simulated CO₂ concentration shows significant variation and gradients near the surface, corresponding to the diurnal change of stability in the atmospheric boundary layer. The time evolution of CO₂ spatial field exhibits the transport processes at night by drainage flows. The CO₂ budget analysis further quantifies the contributions of horizontal and vertical advection. The estimated NEE by only using the sum of the storage change and vertical flux results in large fluctuation during daytime and underestimation of nocturnal respiration by about 40%. When we reduce the effects of strong convection by subtracting a half-hour average from instantaneous variables, as is done in eddy-covariance approach, the daytime fluctuations of estimated NEE are strongly decreased and the estimated nocturnal respiration is within 20% of the prescribed source. Back-streakline analysis shows that the advection source areas of CO₂ reaching the flux towers during fall are mainly from the northwest and southeast along Georgia Strait with a larger advective source area during daytime and a smaller one at night.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat

Analysis of Sequential Micromixing Driven by Sinusoidally Shaped Induced-Charge Electroosmotic Flow

Multi-fluid micromixing, which has rarely been explored, typically represents a highly sought-after technique in on-chip biochemical and biomedical assays. Herein, we propose a novel micromixing approach utilizing induced-charge electroosmosis (ICEO) to implement multicomplex mixing between parallel streams. The variations of ICEO microvortices above a sinusoidally shaped floating electrode (SSFE) are first investigated to better understand the microvortex development and the resultant mixing process within a confined channel. On this basis, a mathematical model of the vortex index is newly developed to predict the mixing degree along the microchannel. The negative exponential distribution obtained between the vortex index and mixing index demonstrates an efficient model to describe the mixing performance without solving the coupled diffusion and momentum equations. Specifically, sufficient mixing with a mixing index higher than 0.9 can be achieved when the vortex index exceeds 51, and the mixing efficiency reaches a plateau at an AC frequency close to 100 Hz. Further, a rectangle floating electrode (RFE) is deposited before SSFE to enhance the controlled sequence for three-fluid mixing. One side fluid can fully mix with the middle fluid with a mixing index of 0.623 above RFE in the first mixing stage and achieve entire-channel mixing with a mixing index of 0.983 above SSFE in the second mixing stage, thereby enabling on-demand sequential mixing. As a proof of concept, this work can provide a robust alternative technique for multi-objective issues and structural design related to mixers

Effect of Vertical Permeability Heterogeneity in Stratified Formation on Electricity Generation Performance of Enhanced Geothermal System

Because geologic sedimentation and hydrofracturing processes are not homogeneous, the reservoirs of enhanced geothermal systems (EGSs) are also heterogeneous; this has a significant influence on the electricity generation performance of EGS. Presently, there are a lack of systematic and profound studies on the effect of vertical permeability heterogeneity in stratified formation on the electricity generation performance of EGS. In order to uncover the effect of vertical permeability heterogeneity on electricity generation performance of EGS, in this work we analyzed the influence of vertical permeability heterogeneity on electricity generation performance of EGS through a numerical method based on geological data at the Yangbajing geothermal field. The results indicate that when the average permeability of stratified formations is constant for a homogeneous reservoir, the system attains maximum water production rate, maximum electric power, minimum reservoir impedance and maximum pump power; with the increasing of the vertical permeability heterogeneity, the water production rate gradually decreases, the electric power gradually declines, the reservoir impedance gradually increases and the pump power gradually declines. When the average permeability of stratified formations is constant, with the increasing of the vertical permeability heterogeneity, the injection pressure and energy efficiency only changes very slightly; this indicates that the vertical permeability heterogeneity is not the main factor affecting the system injection pressure and energy efficiency