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Chinese Physics B 2022年第1期31卷 711-719页

作者： Semba Sherehe Huiyun Wan Changgui Gu Huijie Yang Department of Systems Science University of Shanghai for Science and TechnologyShanghai 200093China Faculty of Science Dar es Salaam University College of EducationUniversity of Dar es SalaamDar es SalaamTanzania

Stock markets in the world are linked by complicated and dynamical relationships into a temporal *** works have provided us with rich findings from the topological properties and their evolutionary trajectories,but the underlying dynamical mechanism is still not in *** the present work,we proposed a technical scheme to reveal the dynamical law from the temporal *** index records for the global stock markets form a multivariate time *** separates the series into segments and calculates the information flows between the markets,resulting in a temporal market network representing the state and its *** the technique of the Koopman decomposition operator is adopted to find the law stored in the information *** results show that the stock market system has a high flexibility,i.e.,it jumps easily between different *** information flows mainly from high to low volatility stock *** the dynamical process of information flow is composed of many dynamic modes distribute homogenously in a wide range of periods from one month to several ten years,but there exist only nine modes dominating the macroscopic patterns.

关键词： transfer entropy Koopman operator stock markets

Geochemistry and Sm-Nd systematics of the 1.67 Ga Buanji Group of southwestern Tanzania: Paleo-weathering, provenance and paleo-tectonic setting implications

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Geoscience Frontiers 2017年第5期8卷 1025-1037页

作者： Charles H.Kasanzu Makenya A.H.Maboko Shukrani Manya Department of Geology University of Dar es Salaam P.O. Box 35052 Dar es Salaam Tanzania

We present major and trace and Nd-isotopic data of the^1.67 Ga Buanji Group of southwestern Tanzania in order to constrain the nature of their protolith and the intensity of chemical weathering in the source terranes and make inferences on the nature of climatic conditions during the late Paleoproterozoic in the region. Major and trace element contents of the shales from three stratigraphic formations are comparable to those of the post-Archaean Australian Shale(PAAS) and the average Proterozoic Shale(PS). They are characterized by enrichments in LREE relative to HREE((La/Yb)_(CN)=9.07-13.2;(Gd/Yb)cN = 1.51-1.85) and negative Eu anomalies(Eu/Eu~* = 0.61-0.81); features which are comparable to those of PAAS and PS, indicating upper continental sources. Provenance proxy ratios,together with abundances of Cr, Ni, Co and V that increase up-stratigraphy suggest a decreasing input of felsic detritus up-stratigraphy. Chemical Indices of Alteration(CIA) for the lower, middle and upper Buanji formations are 81. 76 and 79, respectively. These indices largely indicate intermediate(ca. 60-80)to extreme(>80) weathering intensities of the precursor rocks. These observations may suggest the prevalence of warm, humid climates during the late Paleoproterozoic in the *** lower Buanji Formation yielded a depleted mantle Nd model age(T_(DM)) of 、2100 Ma which indicates an Eburnean parentage. T_(DM) ages of 2486-2155 Ma and 2535-2379 Ma obtained from middle and upper Buanji formations, respectively, suggest a progressive increase of sedimentary input from the Tanzania Craton up-stratigraphy. The Eburnean T_(DM) ages of the lower Buanji rocks are attributed to their derivation through denudation of a decaying topographic high composed predominantly of rocks that were generated during the Palaeoproterozoic Ubendian orogenesis, possibly in the realm of Columbian Supercontinent assembly. Overlapping T_(DM) ages between the middle and upper Buanji formations suggest multiple sources i

关键词： Buanji Group Shales Source weathering conditions Provenance

Apatite fission track and (U-Th)/He thermochronology from the Archean Tanzania Craton: Contributions to cooling histories of Tanzanian basement rocks

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Geoscience Frontiers 2017年第5期8卷 999-1007页

作者： Charles H. Kasanzu Department of Geology University of Dar es Salaam P.O.Box 35052 Dar es Salaam Tanzania

Borehole and surface samples from the Archean Tanzania Craton were analysed for apatite fission track(AFT) and(U-Th)/He data with the aim of deciphering cooling histories of the basement rocks. Fission track dates from borehole and outcrop samples are Carboniferous-Permian(345± 33.3 Ma to271±31.7 Ma) whereas(U-Th)/He dates are Carboniferous-Triassic(336±45.8 Ma to 213±29 Ma) for outcrop grains and are consistently younger than corresponding AFT dates. Single grain(U-Th)/He dates from the borehole are likely to be flawed by excessive helium implantation due to their very low effective uranium contents, radiation damage and grain sizes. All AFT and(U-Th)/He dates are significantly younger than the stratigraphic ages of their host rocks, implying that the samples have experienced Phanerozoic elevated paleo-temperatures. Considerations of the data indicate removal of up to 9 km overburden since the *** modelling reveals a protracted rapid cooling event commencing during the early Carboniferous(ca. 350 Ma) at rates of 46 m/Ma ending in the Triassic(ca. 220 Ma). The model also suggests minor cooling during the Cretaceous of the samples to surface temperatures. The suggested later cooling event remains to be tested. The major cooling phase during the Carboniferous is interpreted to be associated with compressional tectonics during the Variscan Orogeny sensu far field induced stresses. Coeval sedimentation in the Karoo basins in the region suggests that most of the cooling of cratonic rocks during the Carboniferous was associated with denudation.

关键词： Thermochronology Exhumation Tanzania Craton

Diversity and distribution pattern of riparian plant species in the Wami River system, Tanzania

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Journal of Plant Ecology 2017年第2期10卷 259-270页

作者： Cosmas Mligo Department of Botany University of Dar es SalaamPO Box 35060Dar es SalaamTanzania

Aims The Wami River system is among the most important rivers for ripar-ian plant biodiversity conservation but it is potentially threatened by anthropogenic *** study was aimed to determine riparian plant species diversity and distribution patterns in relation to the anthropogenic *** The transect method was used to collect vegetation *** were established perpendicular to the river at intervals of 50 m downstream and five plots were systematically established,sepa-rated by 5-m distance along each *** Findings A total of 261 plant species in 68 families were recorded in the Wami River system with a Shannon diversity index in the range of 1.63-2.94 and a significantly decreasing trend *** the two-way indicator species analysis(TWiNSPAN),three plant communities(A,B and C)emerged based on variations in riparian plant species composition among *** correspondence analysis(CCA)indicated that the spatial pattern of riparian plant species was significantly influenced by environmental *** implies that the plant species composition gradients and spatial assemblages of vegetation communities are a result of human *** of the fragile nature of the riparian system,some species are more vulnerable than others and hence there is an urgent need for better land use planning to conserve riparian plant biodiversity in the sub-basin of Wami River.

关键词： communities CCA disturbances diversity riparian vegetation Wami River

Learning a Deep Predictive Coding Network for a Semi-Supervised 3D-Hand Pose estimation

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1371-1379页

作者： Jamal Banzi Isack Bulugu Zhongfu Ye Sokoine university Morogoro 3000Tanzania university of dar-es-salaam Dar-es-Salaam 35091Tanzania Department of Electronic Engineering and Information Science University of Science and Technology of ChinaHefei 230026China IEEE

In this paper we present a CNN based approach for a real time 3 D-hand pose estimation from the depth *** discriminative approaches have achieved remarkable success but are facing two main challenges:Firstly,the methods are fully supervised hence require large numbers of annotated training data to extract the dynamic information from a hand ***,unreliable hand detectors based on strong assumptions or a weak detector which often fail in several situations like complex environment and multiple *** contrast to these methods,this paper presents an approach that can be considered as semi-supervised by performing predictive coding of image sequences of hand poses in order to capture latent features underlying a given image without *** hand is modelled using a novel latent tree dependency model(LDTM)which transforms internal joint location to an explicit *** the modeled hand topology is integrated with the pose estimator using data dependent method to jointly learn latent variables of the posterior pose appearance and the pose configuration ***,an unsupervised error term which is a part of the recurrent architecture ensures smooth estimations of the final *** on three challenging public datasets,ICVL,MSRA,and NYU demonstrate the significant performance of the proposed method which is comparable or better than state-of-the-art approaches.

关键词： Convolutional neural networks deep learning hand pose estimation human-machine interaction predictive coding recurrent neural networks unsupervised learning

SmartMicro Grid Energy System Management Based on Optimum Running Cost for Rural Communities in Rwanda

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Energy Engineering 2024年第7期121卷 1805-1821页

作者： Fabien Mukundufite Jean Marie Vianney Bikorimana Alexander Kyaruzi Lugatona Electrical and Electronic Engineering Department University of RwandaKigaliRwanda Electrical Engineering Department University of Dar es SalaamDar es SalaamTanzania

The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by ***,the aforementioned goal is challenged by households that are scattered in remote *** far,Solar Home Systems(SHS)have mostly been applied to increase electricity access in rural *** have continuous constraints to meet electricity demands and cannot run income-generating *** current research presents the feasibility study of electrifying Remera village with the smart microgrid as a case *** renewable energy resources available in Remera are the key sources of electricity in that *** generation capacity is estimated based on the load *** microgrid configurations are simulated with HOMER,and the genetic algorithm is used to analyze the optimum *** analyzing the impact of operation and maintenance costs,the results show that the absence of subsidies increases the levelized cost of electricity(COE)five times greater than the electricity price from the public *** microgrid made up of PV,diesel generator,and batteries proved to be the most viable solution and ensured continuous power supply to *** considering the subsidies,COE reaches 0.186$/kWh,a competitive price with electricity from public utilities in Rwanda.

关键词： Load demand load profile optimum running cost power demand satisfaction smart meters and smart micro grid

Citizen sensors or extreme publics? Transparency and accountability interventions on the mobile geoweb

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International Journal of Digital Earth 2014年第7期7卷 516-533页

作者： Y.Georgiadou J.H.Lungo C.Richter Faculty of Geo-information Science and Earth Observation(ITC) University TwenteEnschedeThe Netherlands College of Information and Communication Technologies(CoICT) University Dar es SalaamDar es SalaamTanzania

Transparency and Accountability(T&A)interventions are emergent social technologies in middle and low-income *** bring together citizen sensors,mobile communications,geo-browsers and social organization to raise public awareness on the extent of governance deficits,and monitor government’s(in)*** to their novelty,almost all we know about the effectiveness of T&A interventions comes from gray *** citizen sensors radically increase the transparency of the state,or are changes brought about by T&A interventions more likely to be incremental?We review the literature on transparency policies and describe their drivers,characteristics and supply-demand *** discuss promising cases of T&A interventions in East Africa,the empirical focus of an on-going collaborative research *** conclude that the effect of T&A interventions is more likely to be incremental and mediated by existing organizations and professional users who populate the space between the state and *** elements at the interface between supply and demand seem rather crucial for designers of T&A interventions:accountability-relevant data and extreme publics.

关键词： citizen sensors transparency accountability-relevant data extreme publics mobile geoweb

Deep Earth Processes,Their Effects in the Interior,on the Surface,to Living Organims and Biodiversities

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地学前缘 2009年第S1期16卷 215-216页

作者： Didas Makoye M Malimi Sapiance university of dar es salaam

Interior earth is very hot but consists of concentric layers of varying chemical compositions,pressure and *** concentric layers(shells)are the crust which is the outermost shell,mantle which is the middle layer and c... 详细信息

关键词： internal structure of the Earth driving force mechanisms products and their effects solutions

The Opportunities and Challenges of Geotourism:A Case Study in Oldonyo Lengai in Tanzania

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地学前缘 2009年第S1期16卷 293-294页

作者： Stephen Joseph Nyagonde Constantine Deus Shirati College of Natural and Applied Science University of Dar es Salaam College of Arts and Social Science University of Dar es Salaam

Both geoparks and geosites are unique geological features of spectacular importance to earth science (global scientific importance) and the surrounding *** Oldonyo Lengai(The God for the Maasai people and unique activ... 详细信息

关键词： Oldonyo Lengai geotourism opportuneities and challenges