scholarly journals Mechanisms of Mining Seismicity under Large Scale Exploitation with Multikey Strata

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hu He ◽  
Linming Dou ◽  
Anye Cao ◽  
Jun Fan
Keyword(s):  
Large Scale ◽  
Coal Mines ◽  
Mining Seismicity ◽  
Key Strata ◽  
Time Space ◽  
Released Energy ◽  
Chinese Coal ◽  
Mining Tremors ◽  
Limit Span ◽  
Observing Systems

The dynamic disasters are aggravating with the increase of exploitation scale and intensity in Chinese coal mines, to further understand this problem, we studied the mechanisms of mining tremors induced by key strata movement and instability under large scale exploitation. First the mechanisms were categorized into two groups that is main key strata fracture and movement as well as subkey strata instability again under adjacent mining activities. Based on the key strata theory in ground control we revealed three basic mechanisms of key strata destabilization that are rotary and sliding of low subkey strata, shear sliding of the high subkey strata, and the main key strata rupture and cave at limit span, respectively. The microseismic observing systems were applied to monitor the mining tremor events and verify the theoretical analysis in different coal mines. The characteristics of time-space evolution of tremors show that low inferior key strata causing the most, followed by the high inferior key strata and the main key strata least, however the released energy was just opposite.

Time–Space Characteristics of Diurnal Rainfall over Borneo and Surrounding Oceans as Observed by TRMM-PR

2006 ◽  
Vol 19 (7) ◽  
pp. 1238-1260 ◽  
Author(s):  
Hiroki Ichikawa ◽  
Tetsuzo Yasunari
Keyword(s):  
Diurnal Cycle ◽  
Large Scale ◽  
Intraseasonal Variability ◽  
Phase Speed ◽  
Tropical Rainfall Measuring Mission ◽  
Heavy Precipitation ◽  
Circulation Pattern ◽  
Leeward Side ◽  
Convective Rainfall ◽  
Time Space

Abstract Five years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data were used to investigate the time and space characteristics of the diurnal cycle of rainfall over and around Borneo, an island in the Maritime Continent. The diurnal cycle shows a systematic modulation that is associated with intraseasonal variability in the large-scale circulation pattern, with regimes associated with low-level easterlies or westerlies over the island. The lower-tropospheric westerly (easterly) components correspond to periods of active (inactive) convection over the island that are associated with the passage of intraseasonal atmospheric disturbances related to the Madden–Julian oscillation. A striking feature is that rainfall activity propagates to the leeward side of the island between midnight and morning. The inferred phase speed of the propagation is about 3 m s−1 in the easterly regime and 7 m s−1 in the westerly regime. Propagation occurs over the entire island, causing a leeward enhancement of rainfall. The vertical structure of the developed convection/rainfall system differs remarkably between the two regimes. In the easterly regime, stratiform rains are widespread over the island at midnight, whereas in the westerly regime, local convective rainfall dominates. Over offshore regions, convective rainfall initially dominates then gradually decreases in both regimes, while the storms develop into deeper convective systems in the easterly regime. Aside from leeward rainfall propagation, shallow storms develop over the South China Sea region during the westerly regime, resulting in heavy precipitation from midnight through morning.

Variations in Pathogenicity of Three Different Forms of Rhizoctonia Inoculum and Assessment of Cultivar Resistance of Sugar Beet

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Haque ME ◽  
◽  
Parvin MS ◽  
Keyword(s):  
Seed Germination ◽  
Sugar Beet ◽  
Root Rot ◽  
Large Scale ◽  
Culture Media ◽  
Damping Off ◽  
Require Time ◽  
Time Space ◽  
The Usa

Rhizoctonia solani causes pre-emergence and post-emergence damping-off, as well as crown and root rot of sugar beet (Beta vulgaris L.), which significantly affects the yield returns in the USA and Europe. The pathogen overwinters as sclerotia or melanized mycelium. Traditionally, the resistance of cultivars to R. solani is evaluated by scoring disease reactions at the crowns and roots of older seedlings, thus resistance is not evaluated during seed germination. Moreover, earlier studies evaluated cultivars resistance to R. solani using colonized whole barley or wheat grains which, unlike sclerotia, are artificial inocula of the pathogen that require time, space and technical know-how to produce. Moreover, colonized grains are prone to contamination with other pathogens, consumed by rodents/birds while applied in the field, and are often uneconomic. Considering those limitations, a study was undertaken (1) to develop in vitro methods to generate large-scale sclerotia, (2) to compare pathogenic potentials of sclerotia, mycelia, and colonized barley grains for optimization of dampingoff assays, and (3) to evaluate Rhizoctonia resistance of selected commercial cultivars during the seed germination phase. Comparing six different culture media, we found that R. solani had the highest radial growth (8.9 ± 0.04, cm³) at 8-days and the maximum number of sclerotia produced (203 ± 4.6) at 28-days in CV8 medium. We demonstrated significant differences in pathogenicity of the three different forms of R. solani inocula and susceptibility of cultivars to preand post-emergence damping-off. The highest pre-emergence damping-off and root rot were observed with sclerotia, and the highest post-emergence dampingoff was recorded with both sclerotial and colonized barley inocula. In addition, varietal differences in susceptibility to pre- and post-emergence damping-off were noted. The highest pre-emergence damping-off was recorded on cv Crystal 101RR and lowest in Maribo MA 504. The highest post-emergence damping-off was recorded on BTS 8500 and the lowest in Crystal 467. The maximum mean root rot was observed in BTS 8500, BTS 8606, and Crystal 101R. Our studies demonstrated that sclerotia serve as efficient natural inocula, reemphasized that host-pathogen interactions differ at the early vs. late stages of sugar beet growth, and highlighted the need to reevaluate commercial sugar beet cultivars for resistance at the seed germination stage.

Empirical Studies on the Functional Complexity of Software in Large-Scale Software Systems

2011 ◽  
Vol 3 (3) ◽  
pp. 23-42 ◽  
Author(s):  
Yingxu Wang ◽  
Vincent Chiew
Keyword(s):  
Cognitive Complexity ◽  
Large Scale ◽  
Complexity Analysis ◽  
Software Systems ◽  
Development Effort ◽  
Analysis Tool ◽  
Software System ◽  
Time Space ◽  
Functional Complexity ◽  
Scope Problem

Functional complexity is one of the most fundamental properties of software because almost all other software attributes and properties such as functional size, development effort, costs, quality, and project duration are highly dependent on it. The functional complexity of software is a macro-scope problem concerning the semantic properties of software and human cognitive complexity towards a given software system; while the computational complexity is a micro-scope problem concerning algorithmic analyses towards machine throughput and time/space efficiency. This paper presents an empirical study on the functional complexity of software known as cognitive complexity based on large-scale samples using a Software Cognitive Complexity Analysis Tool (SCCAT). Empirical data are obtained with SCCAT on 7,531 programs and five formally specified software systems. The theoretical foundation of software functional complexity is introduced and the metric of software cognitive complexity is formally modeled. The functional complexities of a large-scale software system and the air traffic control systems (ATCS) are rigorously analyzed. A novel approach to represent software functional complexities and their distributions in software systems is developed. The nature of functional complexity of software in software engineering is rigorously explained. The relationship between the symbolic and functional complexities of software is quantitatively analyzed.

Optimizing Cash Management for Large Scale Bank Operations

2010 ◽  
Vol 1 (2) ◽  
pp. 17-31
Author(s):  
Mark Frost ◽  
Jeff Kennington ◽  
Anusha Madhavan
Keyword(s):  
Federal Reserve ◽  
Large Scale ◽  
Programming Model ◽  
Cash Management ◽  
Cost Component ◽  
Time Space ◽  
Currency Management ◽  
The Cost ◽  
Reserve System ◽  
Computational Solution

The Federal Reserve System (Fed) provides currency services to banks, including sorting currency into fit and non-fit bills and repackaging bills for redistribution. To reduce the cost of currency management operations, many banks make Fed deposits and withdrawals of the same denomination each week. In July 2007, the Fed introduced fees for making both deposits and withdrawals during a given Monday through Friday. Recognizing an opportunity, Fiserv Corporation initiated a project to optimize bank vault inventories across time and space. This article presents the integer programming model developed to assist Fiserv clients reduce the logistics cost component of cash management. The model is implemented in software using OPL. The underlying configuration is a time-space multi-commodity network with a fixed-charge cost structure. The authors report on a successful pilot study and present an efficient heuristic procedure that can be used to reduce computational solution times from hours to a few minutes.

scholarly journals Precambrian faulting episodes and insights into the tectonothermal history of North Australia: Microstructural evidence and K–Ar, <sup>40</sup>Ar–<sup>39</sup>Ar, and Rb–Sr dating of syntectonic illite from the intracratonic Millungera Basin

2020 ◽  
Author(s):  
I. Tonguç Uysal ◽  
Claudio Delle Piane ◽  
Andrew Todd ◽  
Horst Zwingmann
Keyword(s):  
Large Scale ◽  
Active Tectonics ◽  
Mineral Resources ◽  
Sedimentary Basins ◽  
Integrated Approach ◽  
Space Distribution ◽  
Seismic Survey ◽  
North Central ◽  
Time Space ◽  
Central Australia

Abstract. Australian terranes concealed beneath Mesozoic cover record complex Precambrian tectonic histories involving a successive development of several Proterozoic to Paleozoic orogenic systems. This study presents an integrated approach combining K–Ar, 40Ar–39Ar, and Rb–Sr geochronology of Precambrian authigenic illites from the recently discovered Millungera Basin in north-central Australia. Brittle deformation and repeated fault activity are evident from the sampled cores and their microstructures, probably associated with the large-scale faults inferred from interpretations of seismic survey. Rb–Sr isochron, 40Ar–39Ar total gas, and K–Ar ages are largely consistent indicating late Mesoproterozoic and early Proterozoic episodes (~ 1115 ± 26 Ma, ~ 1070 ± 25 Ma, ~ 1040 ± 24 Ma, ~ 1000 ± 23 Ma, and ~ 905 ± 21 Ma) of active tectonics in north-central Australia. K–Ar results show that illites from fault gouges and authigenic matrix illites in undeformed adjacent sandstones precipitated contemporaneously, indicating that advection of tectonically mobilised fluids extended into the undeformed wall rocks above or below the fracture and shear (fault gouge) zones. This study provides insight into the enigmatic time-space distribution of Precambrian tectonic zones in central Australia, which are responsible for the formation of a number of sedimentary basins with significant energy and mineral resources.

scholarly journals Time-space characterization of droughts in the São Francisco river catchment using the Standard Precipitation Index and continuous wavelet transform

RBRH ◽  
2019 ◽  
Vol 24 ◽  
Author(s):  
Marcus Suassuna Santos ◽  
Veber Afonso Figueiredo Costa ◽  
Wilson dos Santos Fernandes ◽  
Rafael Pedrollo de Paes
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Continuous Wavelet Transform ◽  
Large Scale ◽  
Continuous Wavelet ◽  
River Catchment ◽  
Time Space ◽  
L Moments ◽  
Space Characterization

ABSTRACT This paper focuses on time-space characterization of drought conditions in the São Francisco River catchment, on the basis of wavelet analysis of Standardized Precipitation Index (SPI) time series. In order to improve SPI estimation, the procedures for regional analysis with L-moments were employed for defining statistically homogeneous regions. The continuous wavelet transform was then utilized for extracting time-frequency information from the resulting SPI time series in a multiresolution framework and for investigating possible teleconnections of these signals with those obtained from samples of the large-scale climate indexes ENSO and PDO. The use of regional frequency analysis with L-moments resulted in improvements in the estimation of SPI time series. It was observed that by aggregating regional information more reliable estimates of low frequency rainfall amounts were obtained. The wavelet analysis of climate indexes suggests that the more extreme dry periods in the study area are observed when the cold phase of both ENSO and the PDO coincides. While not constituting a strict cause effect relationship, it was clear that the more extreme droughts are consistently observed in this situation. However, further investigation is necessary for identifying particularities in rainfall patterns that are not associated to large-scale climate anomalies.

scholarly journals GPS–Cellular Drifter Technology for Coastal Ocean Observing Systems

2005 ◽  
Vol 22 (9) ◽  
pp. 1381-1388 ◽  
Author(s):  
J. Carter Ohlmann ◽  
Peter F. White ◽  
Andrew L. Sybrandy ◽  
P. Peter Niiler
Keyword(s):  
Real Time ◽  
Coastal Ocean ◽  
Hf Radar ◽  
Near Surface ◽  
Spatial And Temporal Scales ◽  
Time Space ◽  
Position Data ◽  
Ocean Observing ◽  
Ocean Observing Systems ◽  
Observing Systems

Abstract A drifter for observing small spatial and temporal scales of motion in the coastal zone is presented. The drifter uses GPS to determine its position, and the Mobitex terrestrial cellular communications system to transmit the position data in near–real time. This configuration allows position data with order meter accuracy to be sampled every few minutes and transmitted inexpensively. Near-real-time transmission of highly accurate position data enables the drifters to be retrieved and redeployed, further increasing economy. Drifter slip measurements indicate that the drifter follows water to within ∼1–2 cm s−1 during light wind periods. Slip values &gt;1 cm s−1 are aligned with the direction of surface wave propagation and are 180° out of phase, so that the drifter “walks” down waves. Nearly 200 drifter tracks collected off the Santa Barbara, California, coast show comparisons with high-frequency (HF) radar observations of near-surface currents that improve by roughly 50% when the average drifter values are computed from more than 25 observations within a 2-km square HF radar bin. The improvement is the result of drifter resolution of subgrid-scale eddies that are included in time–space-averaged HF radar fields. The average eddy kinetic energy on 2-km space and hour time scales is 25 cm2 s−2, when computed for bins with more than 25 drifter observations. Comparisons with trajectories that are computed from HF radar data show mean separation velocities of 5 and 9 cm s−1 in the along- and across-shore directions, respectively. The drifters resolve scales of motion that are not present in HF radar fields, and are thus complementary to HF radar in coastal ocean observing systems.

Recent geological advances in the understanding of the Torres Basin

2013 ◽  
Vol 53 (2) ◽  
pp. 459
Author(s):  
Michael Swift
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Regional Scale ◽  
Coastal Region ◽  
Petroleum Potential ◽  
Structural Style ◽  
Time Space ◽  
Australian Plate ◽  
History Of ◽  
Geological Section

The Torres Basin is a recently discovered Mesozoic basin in the Papuan Plateau, southeast Papua New Guinea. Newly acquired deepwater offshore seismic data and older regional data have been (re)interpreted with the view of defining structural regimes in line with the onshore geological maps and conceptual cross sections. A regional time-space plot has been developed to elucidate the breakup of the northeastern Australian Plate with a focus on the geological history of the Papuan Plateau, which holds the Torres Basin geological section. This in turn has led to a re-evaluation of the structural style and history of the southern coastal region incorporating the East Australian Early Cretaceous Island Arc; it highlights that a significant horizontal structural grain needs to be considered when evaluating the petroleum potential of the region. The southern margin is characterised as a frontal thrust system, similar to the nearby Papuan Basin. A series of regional strike lines in conjunction with the dip lines is used to divide the region into prospective and non-prospective exploration play fairways. The role of transfer faults, basement-detachments faults, regional-scale thrust faults, and recent normal faulting is discussed in the compartmentalisation of the geological section. There is basement-involved anticlinal development on a large scale and a complementary smaller-scale thin-skinned anticlinal trend. These trends are characterised as having significant strike length and breadth. Anticlinal trap fairways have been defined and have similar size and distribution as that of the Papuan Basin.

The Role of Epidemiological Investigation in the Detection of Environmental Carcinogenic Risks

1968 ◽  
Vol 54 (1) ◽  
pp. 23-46
Author(s):  
Rodolfo Saracci ◽  
Umberto Veronesi
Keyword(s):  
Large Scale ◽  
Retrospective Studies ◽  
Space Distribution ◽  
Epidemiological Methods ◽  
Laboratory Studies ◽  
Cancer Etiology ◽  
Common Basis ◽  
Time Space ◽  
Morbidity Data

An introductory review is presented of the uses and limitations of epidemiological methods for investigating cancer etiology. Uses of epidemiological methods can be grouped under three main headings: search af etiological indications, test of etiological hypotheses, and assessment of the effect of large scale prophylactic or therapeutic treatments. The search of etiological indications is chiefly performed through an analysis of mortality and/or morbidity data: time and space distribution of cancers are usually studied and sometimes an investigation on time-space association is added. On this basis etiological hypotheses are formulated and tested using retrospective studies and/or prospective studies: typical examples of these are found in oncological literature. Assessment of the effect of large scale prophylactic or therapeutic treatments, where feasible, is a further check on the soundness of an etiological hypothesis. Limitations intrinsic to the epidemiological approach (as to any merely observational approach) can be partly overcome through close linkage between epidemiologic and experimental oncology; use of mathematical models to interpret on a common basis data from epidemiological and laboratory studies can make easier this task.

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