Woodfuel Use and Its Influence on People’s Livelihood in Ethiopia : Comparison among Three Peasant Associations in Wondo Genet

This study scrutinizes the domestic fuel consumption pattern and relating issues using survey data for households in three Peasant Associations Wosha, Kela, and Basha in Wondo Genet, south-central Ethiopia. It is found that in this region, households are still heavily reliant on traditional biomass fuels, particularly woodfuels (fuelwood and charcoal). Fuelwood is the most common and important fuel type for the majority of households and there are normally three sources for it, namely self-collection from non-private forests, private plantation, and market fuelwood sellers. A multinomial probit model is employed for the empirical analysis and it indicates in Wondo Genet, the probability for households obtaining fuelwood from these three sources is 0.1825, 0.0867, and 0.7308 respectively. Purchasing fuelwood from markets has replaced self-collection as the primary fuelwood source for households. Household size, economic status, availability of crop residues and modern fuels, and location are the main factors affecting households’ choices. In addition, charcoal is the main fuel substitute/ supplement to fuelwood and is also widely used. Transition towards use of modern fuels is taking place slowly among wealthy households, largely restrained by limitations in people’s perception, infrastructure, fuel supply, etc. This implies that the role of government is of extreme importance in the process of energy transition and development of people’s livelihood

Single spin asymmetry in πp\pi p Drell-Yan process

We study the single spin asymmetries for the $\pi p^\uparrow\rightarrow\mu^+\mu^-X$ process. We consider the asymmetries contributed by the coupling of the Boer-Mulders function with the transversity distribution and the pretzelosity distribution, characterized by the $\sin(\phi+\phi_S)$ and $\sin(3\phi-\phi_S)$ azimuthal angular dependence, respectively. We estimate the magnitude of these asymmetries at COMPASS by using proper weighting functions. We find that the $\sin(\phi+\phi_S)$ asymmetry is of the size of a few percent and can be measured through the experiment. The $\sin(3\phi-\phi_S)$ asymmetry is smaller than the $\sin(\phi+\phi_S)$ asymmetry. After a cut on $q_T$, we succeed in enhancing the asymmetry.Comment: 11 pages, 2 figures, final version to appear in PL

Bis(2,4-dichloro­phen­oxy­acetato-κ2 O 1,O 1′)(5,5′-dimethyl-2,2′-bipyridine-κ2 N,N′)cobalt(II)

In the title compound, [Co(C8H5Cl2O3)(C12H12N2)], the CoII atom, lying on a twofold rotation axis, is coordinated by four O atoms from two chelating 2,4-dichloro­phen­oxy­acetate ligands and two N atoms from a 5,5′-dimethyl-2,2′-bipyridine ligand, displaying a distorted octa­hedral geometry. A three-dimensional supra­molecular structure is formed through inter­molecular C—H⋯O hydrogen bonds and π–π stacking inter­actions between the pyridine and benzene rings [centroid–centroid distance = 3.779 (2) Å]

(5,5′-Dimethyl-2,2′-bipyridine-κ2 N,N′)(1-naphthyl­acetato-κO)(1-naphthyl­acetato-κ2 O,O′)zinc hemihydrate

In the title compound, [Zn(C12H9O2)2(C12H12N2)]·0.5H2O, the water mol­ecule lies on a twofold rotation axis. The ZnII atom is coordinated by three O atoms from two 1-naphthyl­acetate ligands, one monodentate and the other asymmetric bidentate chelate, and two N atoms from a 5,5′-dimethyl-2,2′-bipyridine ligand, giving an irregular environment. In the crystal, the complex mol­ecules are inter­linked through the water mol­ecule by O—H⋯Ocarboxyl­ate hydrogen bonds, together with weak C—H⋯O and bipyridine ring π–π stacking inter­actions [ring centroid separation = 3.761 (2) Å], giving a two-dimensional network structure

Discrete-Event Simulation of Ground-Based Timber Harvesting Operations

Operational studies are necessary to support production and management decisions of forest industries. A time study (TS) approach is widely used in timber harvesting operations to understand the performance of individual harvesting machines as well as the entire system. However, several limitations of the TS approach include the use of generalized utilization rates, incapability of capturing interactions among equipment, and model extrapolation in sensitivity analysis. In this study, we demonstrated the use of discrete event simulation (DES) techniques in modeling a ground-based timber harvesting system, and compared the DES results with those of the TS model developed with the same observed data. Although both TS and DES models provided similar estimation results for individual machine cycle times and productivities, the estimated machine utilization rates were somewhat different due to the difference in synthesizing machine processes in each approach. Our sensitivity analysis and model expansion to simulate a hypothetical harvesting system suggest that the DES approach may become an appropriate method for analyzing complex systems especially where interactions among different machine processes are unknown

Novel mesoporous TiO2(B) whisker-supported sulfated solid superacid with unique acid characteristics and catalytic performances

Mesoporous TiO2(B) whisker was firstly applied as a support for synthesizing the novel sulfated solid superacid (SO42−/TiO2(B)). According to NH3-TPD, TG and Py-IR characterization results, it was found that the similar amount of sulfate group on TiO2(B) and anatase showed significantly different acid characteristics and catalytic performances. The total acid amount of SO42−/TiO2(B) was about 1.8 times as anatase-supported sulfated solid superacid (SO42−/Anatase). Simultaneously, the SO42−/TiO2(B) possessed higher percentage of Brønsted acid and more weak-medium acid strength than SO42−/Anatase. These acidic properties endowed SO42−/TiO2(B) with the increased esterification reaction rate and decreased alkylation byproduct selectivity compared with that of SO42−/Anatase. Structure-performance analysis exhibited that there were more bridged bidentate sulfate groups coordinated to the TiO2(B) in SO42−/TiO2(B), which could induce more Ti cations than that of the chelating one. This was the key factor to be responsible for the unique acid characteristics of SO42−/TiO2(B). The present work provides a novel solid superacid and might open a strategy to mediate the acid characteristic for sulfated solid superacid

RocketQAv2: A Joint Training Method for Dense Passage Retrieval and Passage Re-ranking

In various natural language processing tasks, passage retrieval and passage re-ranking are two key procedures in finding and ranking relevant information. Since both the two procedures contribute to the final performance, it is important to jointly optimize them in order to achieve mutual improvement. In this paper, we propose a novel joint training approach for dense passage retrieval and passage re-ranking. A major contribution is that we introduce the dynamic listwise distillation, where we design a unified listwise training approach for both the retriever and the re-ranker. During the dynamic distillation, the retriever and the re-ranker can be adaptively improved according to each other's relevance information. We also propose a hybrid data augmentation strategy to construct diverse training instances for listwise training approach. Extensive experiments show the effectiveness of our approach on both MSMARCO and Natural Questions datasets. Our code is available at https://github.com/PaddlePaddle/RocketQA.Comment: EMNLP 202

Left-right asymmetry for pion and kaon production in the semi-inclusive deep inelastic scattering process

We analyze the left-right asymmetry in the semi-inclusive deep inelastic scattering (SIDIS) process without introducing any weighting functions. With the current theoretical understanding, we find that the Sivers effect plays a key role in our analysis. We use the latest parametrization of the Sivers and fragmentation functions to reanalyze the $\pi^\pm$ production process and find that the results are sensitive to the parametrization. We also extend our calculation on the $K^{\pm}$ production, which can help us know more about the Sivers distribution of the sea quarks and the unfavored fragmentation processes. HERMES kinematics with a proton target, COMPASS kinematics with a proton, deuteron, and neutron target (the information on the neutron target can be effectively extracted from the $^3$He target), and JLab kinematics (both 6 GeV and 12 GeV) with a proton and neutron target are considered in our paper.Comment: 7 latex pages, 11 figures, final version for publication, with references update

A Novel Selective Ensemble Algorithm for Imbalanced Data Classification Based on Exploratory Undersampling

Learning with imbalanced data is one of the emergent challenging tasks in machine learning. Recently, ensemble learning has arisen as an effective solution to class imbalance problems. The combination of bagging and boosting with data preprocessing resampling, namely, the simplest and accurate exploratory undersampling, has become the most popular method for imbalanced data classification. In this paper, we propose a novel selective ensemble construction method based on exploratory undersampling, RotEasy, with the advantage of improving storage requirement and computational efficiency by ensemble pruning technology. Our methodology aims to enhance the diversity between individual classifiers through feature extraction and diversity regularized ensemble pruning. We made a comprehensive comparison between our method and some state-of-the-art imbalanced learning methods. Experimental results on 20 real-world imbalanced data sets show that RotEasy possesses a significant increase in performance, contrasted by a nonparametric statistical test and various evaluation criteria