Spin-glass ground state in a triangular-lattice compound YbZnGaO4_4

We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO$_4$ to be spin glass, including no long-range magnetic order, prominent broad excitation continua, and absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature a.c. susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion to hold also for its sister compound YbMgGaO$_4$, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.Comment: Version as accepted to PR

Indium Tin Oxide@Carbon Core–Shell Nanowire and Jagged Indium Tin Oxide Nanowire

This paper reports two new indium tin oxide (ITO)-based nanostructures, namely ITO@carbon core–shell nanowire and jagged ITO nanowire. The ITO@carbon core–shell nanowires (~50 nm in diameter, 1–5 μm in length,) were prepared by a chemical vapor deposition process from commercial ITO nanoparticles. A carbon overlayer (~5–10 in thickness) was observed around ITO nanowire core, which was in situ formed by the catalytic decomposition of acetylene gas. This carbon overlayer could be easily removed after calcination in air at an elevated temperature of 700°C, thus forming jagged ITO nanowires (~40–45 nm in diameter). The growth mechanisms of ITO@carbon core–shell nanowire and jagged ITO nanowire were also suggested

Genome-Wide Association Studies Using 3VmrMLM Model Provide New Insights into Branched-Chain Amino Acid Contents in Rice Grains

Rice (Oryza sativa L.) is a globally important food source providing carbohydrates, amino acids, and dietary fiber for humans and livestock. The branched-chain amino acid (BCAA) level is a complex trait related to the nutrient quality of rice. However, the genetic mechanism underlying the BCAA (valine, leucine, and isoleucine) accumulation in rice grains remains largely unclear. In this study, the grain BCAA contents and 239,055 SNPs of a diverse panel containing 422 rice accessions were adopted to perform a genome-wide association study (GWAS) using a recently proposed 3VmrMLM model. A total of 357 BCAA-content-associated main-effect quantitative trait nucleotides (QTNs) were identified from 15 datasets (12 BCAA content datasets and 3 BLUP datasets of BCAA). Furthermore, the allelic variation of two novel candidate genes, LOC_Os01g52530 and LOC_Os06g15420, responsible for the isoleucine (Ile) content alteration were identified. To reveal the genetic basis of the potential interactions between the gene and environmental factor, 53 QTN-by-environment interactions (QEIs) were detected using the 3VmrMLM model. The LOC_Os03g24460, LOC_Os01g55590, and LOC_Os12g31820 were considered as the candidate genes potentially contributing to the valine (Val), leucine (Leu), and isoleucine (Ile) accumulations, respectively. Additionally, 10 QTN-by-QTN interactions (QQIs) were detected using the 3VmrMLM model, which were putative gene-by-gene interactions related to the Leu and Ile contents. Taken together, these findings suggest that the implementation of the 3VmrMLM model in a GWAS may provide new insights into the deeper understanding of BCAA accumulation in rice grains. The identified QTNs/QEIs/QQIs serve as potential targets for the genetic improvement of rice with high BCAA levels

A Novel Concurrent Generalized Deadlock Detection Algorithm In Distributed Systems

Detecting deadlocks has been considered an important problem in distributed systems. Many approaches are proposed to handle this issue; however, little attention has been paid on coordinating concurrent execution of distributed deadlock detection algorithms. Previous approaches may report incorrect results (false negatives), and they are inefficient due to lack of proper coordination of concurrent execution. In this paper, we present a novel concurrent coordination algorithm for distributed generalized deadlock detection. The proposed algorithm aims to avoid false negatives and improve the performance when concurrently executing deadlock detection in a distributed system. Our algorithm adopts diffusion computation to distribute probe messages and employs priority-based method to coordinate concurrent algorithm instances. Priority carried in the received probe messages will be locally recorded by each initiator. Instead of being suspended by higher priority algorithm instances, lower priority algorithm instances can accomplish deadlock detection locally. The initiator with the highest priority will receive and collect all related resource requests information from lower priority instances in a hierarchical manner and perform global deadlock detection at last. We evaluate our algorithm on a bunch of event-driven simulations. The experimental results show that our approach can achieve better accuracy and efficiency compared to previous approaches

A Leader Election Based Deadlock Detection Algorithm In Distributed Systems

Deadlock detection is an important and challenge work in distributed systems. Thing becomes more complex when multiple deadlock detection algorithm instances executing currently in the system. In this paper, we propose a leader election based deadlock detection algorithm in distributed system. Our algorithm aims to improve the performance in the condition of concurrent execution. In addition, our algorithm can provide a certain extent of fault tolerance after a current leader fails. We have proved the liveness and safety property of our algorithm. Simulation results show that our algorithm obtains an order of magnitude performance improvement on message complexity

Detecting And Resolving Deadlocks In Mobile Agent Systems

Mobile agents environment is a new application paradigm with unique features such as mobility and autonomy. Traditional deadlock detection algorithms in distributed computing systems do not work well in mobile agent systems due to the unique feature property of the mobile agent. Existing deadlock detection and resolution algorithms in mobile agent systems have limitations such as performance inefficiency and duplicate detection/resolution when multiple mobile agents simultaneously detect/resolve the same deadlock. To address these problems, we propose an improved deadlock detection and resolution algorithm that adopts priority-based technique and lazy reaction strategy. The priority-based technique aims to ensure that there is only one instance of deadlock detection and resolution, and it also helps reduce mobile agent movement and data traffic together with the lazy reaction strategy. The liveness and safety properties of the proposed algorithm are proved in this paper. Theoretical analysis and experimental results show that the proposed algorithm provides better performance in terms of agent movement, data traffic, and execution time

A Fault Tolerant Election-Based Deadlock Detection Algorithm In Distributed Systems

Deadlock detection in a distributed system without shared memory is important to ensure the reliability of the system. It becomes more complex when multiple deadlock detection algorithm instances execute concurrently in the system. In addition, the problem of communication disconnection between computing nodes or processes makes deadlock detection more difficult. Existing centralized algorithms suffer from single point failure of the central controller (due to communication disconnection), and they are performance-inefficient in the case of concurrent execution. In this paper, we extend our previous work (Lu et al. 2016) and propose a fault tolerant deadlock detection algorithm in distributed systems. The extended proposed algorithm can tolerate a certain extent of communication disconnection between computing nodes or processes. A central controller is used to collect requesting conditions, construct a wait-for graph, and detect deadlocks. The proposed algorithm can select a new central controller if the current central leader fails due to communication disconnections. The liveness and safety properties of the proposed algorithm are proved in this paper. Experimental results show that the proposed algorithm provides better performance than most of existing algorithms in terms of message number, data traffic, and execution time. In addition, the proposed algorithm provides additional fault tolerance compared to existing deadlock detection algorithms in the case of communication disconnection

A Novel Priority-Based Deadlock Detection And Resolution Algorithm In Mobile Agent Systems

Deadlock detection and resolution is one of the challenges in mobile agent systems, especially, when concurrent execution (i.e., more than one algorithm instances executing simultaneously) of algorithm instances. In this paper, we propose a deadlock detection and resolution algorithm in mobile agent systems. Priority-based approach is adopted in our algorithm to coordinate concurrent execution of algorithm instances. The liveness and safety properties of our algorithm are proved. Analysis and simulation results indicate that our algorithm can provide better performance and avoid duplicate detection and resolutions of the same deadlock in condition of concurrent execution