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Stock-Price Forecasting Based on XGBoost and LSTM

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Computer Systems Science & engineering 2022年第1期40卷 237-246页

作者： Pham Hoang Vuong Trinh Tan dat Tieu khoi Mai Pham Hoang Uyen Pham The Bao Information Science Faculty Sai Gon UniversityHo Chi Minh City700000Vietnam University of economics and Law Ho Chi Minh City700000Vietnam

Using time-series data analysis for stock-price forecasting(SPF)is complex and challenging because many factors can influence stock prices(e.g.,inflation,seasonality,economic policy,societal behaviors).Such factors can be analyzed over time for *** learning and deep learning have been shown to obtain better forecasts of stock prices than traditional *** study,therefore,proposed a method to enhance the performance of an SPF system based on advanced machine learning and deep learning ***,we applied extreme gradient boosting as a feature-selection technique to extract important features from high-dimensional time-series data and remove redundant ***,we fed selected features into a deep long short-term memory(LSTM)network to forecast stock *** deep LSTM network was used to reflect the temporal nature of the input time series and fully exploit future con-textual *** complex structure enables this network to capture more stochasticity within the stock *** method does not change when applied to stock data or Forex *** results based on a Forex dataset covering 2008–2018 showed that our approach outperformed the baseline autoregressive integrated moving average approach with regard to mean absolute error,mean squared error,and root-mean-square error.

关键词： stock-price forecasting ARIMA XGBoost LSTM deep learning

Nitroxy-and azidomethyl azofurazans as advanced energetic materials

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Defence Technology（防务技术） 2022年第8期18卷 1369-1381页

作者： Aleksei B.Sheremetev Svetlana F.Mel'nikova elizaveta S.kokareva Ruslan e.Nekrutenko kirill V.Strizhenko kyrill Yu Suponitsky Thanh dat Pham Alla N.Pivkina Valery P.Sinditskii Zelinsky Institute of Organic Chemistry Russian Academy of Sciences47 Leninsky ProspMoscow119991Russia Saint Petersburg State Institute of Technology 26 Moskovskii PrSt Petersburg190013Russia Mendeleev University of Chemical Technology Moscow125047Russia N.N.Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences4 Kosygina Str119991MoscowRussia

Progress in the rocket industry is only possible on the basis of new, higher performance and more environmentally friendly materials compared to up-to-date propellant ingredients for liquid, solid, gelled and hybrid propellant systems. In this work, synthetic methods have been developed for the preparation of new energetic azofurazans bearing nitroxymethyl or azidomethyl groups. All prepared compounds were fully characterized by multinuclear NMR and IR spectroscopies, as well as elemental analyses. An analysis of the structural features based on the X-ray single-crystal diffraction made it possible to discuss their influence on the densities of the azofurazans of this study. Thermal decomposition and combustion of nitroxymethyl and azidomethyl azofurazans were studied using a number of complementary experimental techniques, namely thermogravimetry, differential scanning calorimetry, manometry, microthermocouple measurements in the combustion wave. The structural and physical characteristics of these new energetic analogues illustrate the extent to which the nature of the explosophoric groups can be used to tune the performace of the azofurazan framework. These azofurazans possess positive calculated enthalpy of formation and are promising candidates for new environmentally friendly energetic materials.

关键词： Azofurazan Azide Nitrate ester X-ray Combustion

engineering electrode interfaces for telecom-band photodetection in MoS_(2)/Au heterostructures via sub-band light absorption

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Light(Science & Applications) 2023年第12期12卷 2677-2687页

作者： Chengyun Hong Saejin Oh Vu khac dat Sangyeon Pak SeungNam Cha kyung-Hun ko Gyung-Min Choi Tony Low Sang-Hyun Oh Ji-Hee kim Department of energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea Center for Integrated Nanostructure Physics(CINAP) Institute for Basic Science(IBS)Sungkyunkwan UniversitySuwon 16419Republic of Korea School of electronic and electrical engineering Hongik UniversitySeoul 04066Republic of Korea Department of Physics Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of electrical and Computer engineering University of MinnesotaMinneapolisMN 55455USA Department of Physics Pusan National UniversityBusan 46241Republic of Korea

Transition metal dichalcogenide(TMD)layered semiconductors possess immense potential in the design of photonic,electronic,optoelectronic,and sensor ***,the sub-bandgap light absorption of TMD in the range from near-infrared(NIR)to short-wavelength infrared(SWIR)is insufficient for applications beyond the bandgap ***,we report that the sub-bandgap photoresponse of MoS_(2)/Au heterostructures can be robustly modulated by the electrode fabrication method *** observed up to 60%sub-bandgap absorption in the MoS_(2)/Au heterostructure,which includes the hybridized interface,where the Au layer was applied via sputter *** greatly enhanced absorption of sub-bandgap light is due to the planar cavity formed by MoS_(2) and Au;as such,the absorption spectrum can be tuned by altering the thickness of the MoS_(2) *** in the SWIR wavelength range increases due to increased absorption,which means that broad wavelength detection from visible toward SWIR is *** also achieved rapid photoresponse(~150μs)and high responsivity(17 mA W^(-1))at an excitation wavelength of *** findings demonstrate a facile method for optical property modulation using metal electrode engineering and for realizing SWIR photodetection in wide-bandgap 2D materials.

关键词： MoS_(2) absorption electrode

Catalytic Properties of Pt Cluster-Decorated CeO2 Nanostructures

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Nano Research 2011年第1期4卷 61-71页

作者： Lin Feng dat Tien Hoang Chia-kuang Tsung Wenyu Huang Sylvia Hsiao-Yun Lo Jennifer B. Wood Hungta Wang dinyao Tang Peidong Yang Department of Chemistry University of California Berkeley California 94720 USA Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry Merkert Chemistry Center Boston College 2609 Beacon Street Chestnut Hill Massachusetts 02467 USA

Uniform clusters of Pt have been deposited on the surface of capping-agent-free CeO2 nanooctahedra and nanorods using electron beam （e-beam） evaporation. The coverage of the Pt nanocluster layer can be controlled by adjusting the e-beam evaporation time. The resulting e-beam evaporated Pt nanocluster layers on the CeO2 surfaces have a clean surface and clean interface between Pt and CeO2. Different growth behaviors of Pt on the two types of CeO2 nanocrystals were observed, with epitaxial growth of Pt on CeO2 nanooctahedra and random growth of Pt on CeO2 nanorods. The structures of the Pt clusters on the two different types of CeO2 nanocrystals have been studied and compared by using them as catalysts for model reactions. The results of hydrogenation reactions clearly showed the clean and similar chemical surface of the Pt clusters in both catalysts. The support- dependent activity of these catalysts was demonstrated by CO oxidation. The Pt/CeO2 nanorods showed much higher activity compared with Pt/CeO2 nanooctahedra because of the higher concentration of oxygen vacancies in the CeO2 nanorods. The structure-dependent selectivity of dehydrogenation reactions indicates that the structures of the Pt on CeO2 nanorods and nanooctahedra are different. Thes differences arise because the metal deposition behaviors are modulated by the strong metal-metal oxide interactions.

关键词： Nanocrystals nanoclusters interface catalysis

A new section of kaili Formation (Cambrian) and a biostratigraphic study of the boundary interval across the undefined Cambrian Series 2 and Series 3 at Jianshan,Jianhe County,China with a discussion of global correlation based on the first appearance dat

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Progress in Natural Science:Materials International 2008年第12期18卷 1549-1556页

作者： Loren e.Babcock School of earth Sciences Ohio State UniversityColumbusOH 43210USA

A trilobite biostratigraphic study of a new section of the kaili Formation at Jianshan,Chuandong Village,Jianhe County, Guizhou is *** occurrences of key species associated with the Ovatoryctocara granulata-Bathynotus holopygus Zone and the overlying Oryctocephalus indicus Zone that were originally defined from the trilobite assemblages at the Wuliu- Zengjiayan section of the kaili are reported from this new *** first appearance datum (FAD) of Oryctocephalus indicus occurs at the 44.52 m above the base of the *** on study of abundant specimens (n=800) from the kaili Formation, we argue that Oryctocephalus indicus is a widespread taxon with a global *** (Lermontova,1940) from the middle part of the kounamkites Zone of the Amganian Stage in the Molodo River region of Siberia and *** (Sundberg and McCollum,2003) from Nevada,North America are similar to representatives of *** which occur in the *** Zone of the kaili *** and *** are here synonymized with *** (Reed,1910).This study strengthens the Wuliu-Zengjiayan section of the kaili Formation as a candidate section for a Global Stratotype for the base of the unnamed Cambrian Series 3.

关键词： Jianshan section kaili Formation Boundary Cambrian Series 3 Guizhou China

高原鼠兔Ochotona curzoniae自然寿命研究

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兽类学报 1989年第1期9卷 56-62页

作者：王学高戴克华中国科学院西北高原生物研究所

1984至1987年2月在青海湖黑马河地区,以耳标观察法对高原鼠兔Ochotona curzoniae的自然寿命进行了研究。其结果,高原鼠兔的生存曲线呈L型。最大寿命957天,平均寿命119.9天。1986年出生的幼体,第1胎雄鼠平均寿命108天,雌鼠106天,第2胎雄... 详细信息

1984至1987年2月在青海湖黑马河地区,以耳标观察法对高原鼠兔Ochotona curzoniae的自然寿命进行了研究。其结果,高原鼠兔的生存曲线呈L型。最大寿命957天,平均寿命119.9天。1986年出生的幼体,第1胎雄鼠平均寿命108天,雌鼠106天,第2胎雄鼠为58天,雌鼠为66.3天;第3胎雄鼠为24.8天,雌鼠为15.4天。

关键词：高原鼠兔生命表自然寿命鼠兔

efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

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Rice science 2012年第1期19卷 55-63页

作者： k. VIJAY kRISHNA kUMAR S. kR. YeLLAReDDYGARI M. S. ReDDY J. W. kLOePPeR k. S. LAWReNCe X. G. ZHOU H. SUDINI D. e. GROTH S. kRISHNAM RAJU M. e. MILLeR Department of entomology ＆ Plant Pathology Auburn University Auburn Alabama 36849 USA ＆ Acharya N G Ranga Agricultural University Hyderabad 500030 India Department of entomology ＆ Plant Pathology Auburn University Auburn Alabama 36849 USA Texas A ＆ M University Agri-Life Research ＆ Extension Center Texas 77713 USA International Crops Research Institute fo)r the Semi-Arid Tropics (ICRISAT) Hyderabad 502324 India Rice Research Station LSU AgCenter LA 70578 USA Andhra Pradesh Rice Research Institute Maruteru AP 534122 India Department of Biological Sciences Auburn University Auburn Alabama 36849 USA

Rice sheath blight disease （ShB）, caused by Rhizoctonia solani, gives rise to significant grain yield losses. The present study evaluated the efficacy of Integral, the commercial liquid formulation of Bacillus subtilis strain MBI 600, against rice ShB and for plant growth promotion. In greenhouse studies, four log concentrations of Integral （from 2.2×10^6 to 2.2×10^9 cfu/mL） were used as seed treatment （ST）. After 25 d, seedlings were dipped （SD） into Integral prior to transplanting. At 30 d after transplanting （dat）, leaf sheaths were inoculated with immature sclerotia of the pathogen. At 45 dat, a foliar spray （FS） with Integral was applied to some treatments. The fungicide control was 50% carbendazim at 1.0 g/L, and a nontreated control was also included. Overall, there were 10 treatments, each with five replications. ShB severity was rated at 52 dat, and seedling height and number of tillers per plant were rated at 60 dat. In 2009, two field trials evaluated Integral at 2.2×10^8 and 2.2×10^9 cfu/mL. Integral was applied as ST, and seedlings were produced in a nursery bed. After 32 d, seedlings were treated with Integral as SD and transplanted into 10 m^2 blocks. Foliar sprays were given at 45 and 60 dat. There were seven treatments, each with eight replications arranged as a factorial randomized complete block design. At 20 dat, the plots were broadcast inoculated with R. solani produced on rice grains. Seedling height before transplanting, ShB severity at 90 dat, and grain yield at harvest were recorded. Integral at 2.2×10^9 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions. The Integral treatments of ST ＋ SD ＋ FS at 2.2×10^9 cfu/mL significantly suppressed ShB over other treatments. In field studies, Integral provided significant increase of seedling height in nursery, and number of tillers per plant, compared with the control. ShB severity was significantly suppressed with higher concentrations of Integ

关键词： rice sheath blight Rhizoctonia solani plant growth-promoting rhizobacterium Bacillus subtilis

Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem

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Science China(Life Sciences) 2005年第Z2期48卷 980-987页

作者： A.M.Puste P.k.Sarkar D.k.Das Department of Agronomy Faculty of Agriculture Bidhan Chandra Krishi Viswavidyalaya (Agricultural University) Mohanpur-741 252NadiaWest BengalIndia Department of Agricultural Chemistry and Soil Science Faculty of Agriculture Bidhan Chandra Krishi Viswavidyalaya (Agricultural University) Mohanpur-741 252NadiaWest BengalIndia

In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying 'Tal' situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.571 ha-1), matured nut yield of makhana (3.06 t ha-1) and flower stalks of water-lily as vegetables (6.38 t ha-1) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha-1) and inorganic sources (NPk @ 30:20:20 kg ha-1 along with spraying of NPk @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYe (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was favourably

关键词： aquatic food crops INM nitrogen soil & water characterization economics wetland ecosystem.

Tolerance of Maize (<i>Zea mays</i>L.) and Soybean [<i>Glycine max</i>(L.) Merr.] to Late Applications of Postemergence Herbicides

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Agricultural Sciences 2014年第11期5卷 1007-1014页

作者： kris J. Mahoney Robert e. Nurse Peter H. Sikkema University of Guelph Ridgetown Campus Ridgetown Canada Agriculture and Agri-Food Canada Harrow Canada

Seven maize (Zea mays L.) and three soybean [Glycine max (L.) Merr.] field experiments were conducted from 2006 to 2009 at various locations in southern Ontario, Canada to determine the tolerance of these crops to late applications of the maximum labeled herbicide dose. Single and sequential (simulating a spray overlap) applications were evaluated for visible injury, plant height, and crop yield in the absence of weed competition. Maize exhibited excellent tolerance to herbicides applied at the 9- to 10-leaf growth stage as visible injury levels for almost all tested herbicides was similar to the untreated control 7 days after treatment (dat). However, the sequential application of dicamba/diflufenzopyr or foramsulfuron caused 6 and 8% injury 7 dat and 8 and 14% reduction in maize height 28 dat, respectively. The observed injury and stunting were transient as there were no differences in yield at harvest. Soybean displayed good tolerance to most herbicides applied at the 7th trifoliate leaf growth stage as visible injury levels were similar to the untreated control. However, thifensulfuron-methyl was injurious regardless of application and imazethapyr was injurious with sequential applications. For example, single thifensulfuron-methyl, sequential thifensulfuron-methyl, and sequential imazethapyr application treatments caused 35, 48, and 25% injury 7 dat, respectively. Sequential thifensulfuron-methyl treatments also caused a 28 and 17% reduction in soybean height 14 and 28 dat, respectively. Visual injury continued to be detected up to 56 dat for single thifensulfuron-methyl, sequential thifensulfuron-methyl, and sequential imazethapyr treatments. But, soybean yields were reduced by 10% for only sequential thifensulfuron-methyl application treatments. For all other herbicides tested, the yields at harvest were similar to the untreated control. This research demonstrated that maize had exceptional tolerance to all the herbicides used in this study whereas soybean wa

关键词： Critical Weed-Free Period Injury Yield