International inter-rater agreement in scoring acne severity utilizing cloud-based image sharing of mobile phone photographs.

Science.gov (United States)

Foolad, Negar; Ornelas, Jennifer N; Clark, Ashley K; Ali, Ifrah; Sharon, Victoria R; Al Mubarak, Luluah; Lopez, Andrés; Alikhan, Ali; Al Dabagh, Bishr; Firooz, Alireza; Awasthi, Smita; Liu, Yu; Li, Chin-Shang; Sivamani, Raja K

2017-09-01

Cloud-based image sharing technology allows facilitated sharing of images. Cloud-based image sharing technology has not been well-studied for acne assessments or treatment preferences, among international evaluators. We evaluated inter-rater variability of acne grading and treatment recommendations among an international group of dermatologists that assessed photographs. This is a prospective, single visit photographic study to assess inter-rater agreement of acne photographs shared through an integrated mobile device, cloud-based, and HIPAA-compliant platform. Inter-rater agreements for global acne assessment and acne lesion counts were evaluated by the Kendall's coefficient of concordance while correlations between treatment recommendations and acne severity were calculated by Spearman's rank correlation coefficient. There was good agreement for the evaluation of inflammatory lesions (KCC = 0.62, P cloud-based image sharing for acne assessment. Cloud-based sharing may facilitate acne care and research among international collaborators. © 2017 The International Society of Dermatology.

3rd International Symposium on Big Data and Cloud Computing Challenges

CERN Document Server

Neelanarayanan, V

2016-01-01

This proceedings volume contains selected papers that were presented in the 3rd International Symposium on Big data and Cloud Computing Challenges, 2016 held at VIT University, India on March 10 and 11. New research issues, challenges and opportunities shaping the future agenda in the field of Big Data and Cloud Computing are identified and presented throughout the book, which is intended for researchers, scholars, students, software developers and practitioners working at the forefront in their field. This book acts as a platform for exchanging ideas, setting questions for discussion, and sharing the experience in Big Data and Cloud Computing domain.

International Conference on Aerosols, Clouds and the Indian Monsoon

Science.gov (United States)

Singh, Ramesh P.; Tare, Vinod; Tripathi, S. N.

2005-06-01

In recent years, dense haze and fog problems in the northern parts of India have affected the 460 million people living in the Indo-Gangetic basin. Substantial Indian research activities related to aerosols, clouds, and monsoon are taking place in the central and southern parts of India. To attract attention to the problems, a three-day International Conference on Aerosols, Clouds and Indian Monsoon was recently held at the Indian Institute of Technology, Kanpur, in the central part of the Indo-Gangetic basin. About 120 delegates from India, Germany, Greece, Japan, Taiwan, and the United States attended the conference.

Progress in Understanding the Impacts of 3-D Cloud Structure on MODIS Cloud Property Retrievals for Marine Boundary Layer Clouds

Science.gov (United States)

Zhang, Zhibo; Werner, Frank; Miller, Daniel; Platnick, Steven; Ackerman, Andrew; DiGirolamo, Larry; Meyer, Kerry; Marshak, Alexander; Wind, Galina; Zhao, Guangyu

2016-01-01

Theory: A novel framework based on 2-D Tayler expansion for quantifying the uncertainty in MODIS retrievals caused by sub-pixel reflectance inhomogeneity. (Zhang et al. 2016). How cloud vertical structure influences MODIS LWP retrievals. (Miller et al. 2016). Observation: Analysis of failed MODIS cloud property retrievals. (Cho et al. 2015). Cloud property retrievals from 15m resolution ASTER observations. (Werner et al. 2016). Modeling: LES-Satellite observation simulator (Zhang et al. 2012, Miller et al. 2016).

Evaluation of NCMRWF unified model vertical cloud structure with CloudSat over the Indian summer monsoon region

Science.gov (United States)

Jayakumar, A.; Mamgain, Ashu; Jisesh, A. S.; Mohandas, Saji; Rakhi, R.; Rajagopal, E. N.

2016-05-01

Representation of rainfall distribution and monsoon circulation in the high resolution versions of NCMRWF Unified model (NCUM-REG) for the short-range forecasting of extreme rainfall event is vastly dependent on the key factors such as vertical cloud distribution, convection and convection/cloud relationship in the model. Hence it is highly relevant to evaluate the vertical structure of cloud and precipitation of the model over the monsoon environment. In this regard, we utilized the synergy of the capabilities of CloudSat data for long observational period, by conditioning it for the synoptic situation of the model simulation period. Simulations were run at 4-km grid length with the convective parameterization effectively switched off and on. Since the sample of CloudSat overpasses through the monsoon domain is small, the aforementioned methodology may qualitatively evaluate the vertical cloud structure for the model simulation period. It is envisaged that the present study will open up the possibility of further improvement in the high resolution version of NCUM in the tropics for the Indian summer monsoon associated rainfall events.

The structure of the clouds distributed operating system

Science.gov (United States)

Dasgupta, Partha; Leblanc, Richard J., Jr.

1989-01-01

A novel system architecture, based on the object model, is the central structuring concept used in the Clouds distributed operating system. This architecture makes Clouds attractive over a wide class of machines and environments. Clouds is a native operating system, designed and implemented at Georgia Tech. and runs on a set of generated purpose computers connected via a local area network. The system architecture of Clouds is composed of a system-wide global set of persistent (long-lived) virtual address spaces, called objects that contain persistent data and code. The object concept is implemented at the operating system level, thus presenting a single level storage view to the user. Lightweight treads carry computational activity through the code stored in the objects. The persistent objects and threads gives rise to a programming environment composed of shared permanent memory, dispensing with the need for hardware-derived concepts such as the file systems and message systems. Though the hardware may be distributed and may have disks and networks, the Clouds provides the applications with a logically centralized system, based on a shared, structured, single level store. The current design of Clouds uses a minimalist philosophy with respect to both the kernel and the operating system. That is, the kernel and the operating system support a bare minimum of functionality. Clouds also adheres to the concept of separation of policy and mechanism. Most low-level operating system services are implemented above the kernel and most high level services are implemented at the user level. From the measured performance of using the kernel mechanisms, we are able to demonstrate that efficient implementations are feasible for the object model on commercially available hardware. Clouds provides a rich environment for conducting research in distributed systems. Some of the topics addressed in this paper include distributed programming environments, consistency of persistent data

Generating Free-Form Grid Truss Structures from 3D Scanned Point Clouds

Directory of Open Access Journals (Sweden)

Hui Ding

2017-01-01

Full Text Available Reconstruction, according to physical shape, is a novel way to generate free-form grid truss structures. 3D scanning is an effective means of acquiring physical form information and it generates dense point clouds on surfaces of objects. However, generating grid truss structures from point clouds is still a challenge. Based on the advancing front technique (AFT which is widely used in Finite Element Method (FEM, a scheme for generating grid truss structures from 3D scanned point clouds is proposed in this paper. Based on the characteristics of point cloud data, the search box is adopted to reduce the search space in grid generating. A front advancing procedure suit for point clouds is established. Delaunay method and Laplacian method are used to improve the quality of the generated grids, and an adjustment strategy that locates grid nodes at appointed places is proposed. Several examples of generating grid truss structures from 3D scanned point clouds of seashells are carried out to verify the proposed scheme. Physical models of the grid truss structures generated in the examples are manufactured by 3D print, which solidifies the feasibility of the scheme.

A Modeling Study of the Spatial Structure of Electric Fields Generated by Electrified Clouds with Screening Layers

Science.gov (United States)

Biagi, C. J.; Cummins, K. L.

2015-12-01

The growing possibility of inexpensive airborne observations of electric fields using one or more small UAVs increases the importance of understanding what can be determined about cloud electrification and associated electric fields outside cloud boundaries. If important information can be inferred from carefully selected flight paths outside of a cloud, then the aircraft and its instrumentation will be much cheaper to develop and much safer to operate. These facts have led us to revisit this long-standing topic using quasi-static, finite-element modeling inside and outside arbitrarily shaped clouds with a variety of internal charge distributions. In particular, we examine the effect of screening layers on electric fields outside of electrified clouds by comparing modeling results for charged clouds having electrical conductivities that are both equal to and lower than the surrounding clear air. The comparisons indicate that the spatial structure of the electric field is approximately the same regardless of the difference in the conductivities between the cloud and clear air and the formation of a screening layer, even for altitude-dependent electrical conductivities. This result is consistent with the numerical modeling results reported by Driscoll et al [1992]. The similarity of the spatial structure of the electric field outside of clouds with and without a screening layer suggests that "bulk" properties related to cloud electrification might be determined using measurements of the electric field at multiple locations in space outside the cloud, particularly at altitude. Finally, for this somewhat simplified model, the reduction in electric field magnitude outside the cloud due to the presence of a screening layer exhibits a simple dependence on the difference in conductivity between the cloud and clear air. These results are particularly relevant for studying clouds that are not producing lightning, such as developing thunderstorms and decaying anvils

Jovian cloud structure and velocity fields

International Nuclear Information System (INIS)

Mitchell, J.L.; Terrile, R.J.; Collins, S.A.; Smith, B.A.; Muller, J.P.; Ingersoll, A.P.; Hunt, G.E.; Beebe, R.F.

1979-01-01

A regional comparison of the cloud structures and velocity fields (meridional as well as zonal velocities) in the jovian atmosphere (scales > 200 km) as observed by the Voyager 1 imaging system is given. It is shown that although both hemispheres of Jupiter show similar patterns of diminishing and alternating eastward and westward jets as one progresses polewards, there is a pronounced asymmetry in the structural appearance of the two hemispheres. (UK)

Ultraviolet interstellar absorption toward stars in the small Magellanic Cloud. III. THe structure and kinematics of Small Magellanic Cloud

International Nuclear Information System (INIS)

Fitzpatrick, A.L.

1985-01-01

The structure and kinematical properties of the Small Magellanic Cloud (SMC) are investigated by combining ultraviolet data obtained from the International Ultraviolet Explorer (IUE) satellite with existing optical and radio data. The SMC structure is complicated, undoubtedly a result of gravitational interaction with the Milky Way and the Large Magellanic Cloud, and is poorly understood. It has been known for some time that most of the H I in the SMC is concentrated in two complexes at velocities of approximately 134 and 167 km s -1 (heliocentric). Recent 21 cm emission surveys have revealed two additional, widespread H I components at approx.100 and approx.200 km s -1 . With the radio data alone, however, the relative line-of-sight locations of those complexes cannot be determined, nor can the associations of stars with the complexes be deduced. By using the ultraviolet interstellar absorption-line data in conjunction with radio and optical data, the stellar-interstellar kinematical and morphological relationships can be established. We find that in the southwest region of the SMC, most of the stars observed by IUE, including a group with only low-dispersion IUE spectra, are associated with the 134 km s -1 H I complex

Lxcloud: a prototype for an internal cloud in HEP. Experiences and lessons learned

International Nuclear Information System (INIS)

Goasguen, Sebastien; Moreira, Belmiro; Roche, Ewan; Schwickerath, Ulrich

2012-01-01

Born out of the desire to virtualize our batch compute farm CERN has developed an internal cloud known as lxcloud. Since December 2010 it has been used to run a small but sufficient part of our batch workload thus allowing operational and development experience to be gained. Recently, this service has evolved to a public cloud allowing selected physics users an alternate way of accessing resources.

Turbulence and star formation in molecular clouds

International Nuclear Information System (INIS)

Larson, R.B.

1981-01-01

Data for many molecular clouds and condensations show that the internal velocity dispersion of each region is well correlated with its size and mass, and these correlations are approximately of power-law form. The dependence of velocity dispersion on region size is similar to the Kolmogoroff law for subsonic turbulence, suggesting that the observed motions are all part of a common hierarchy of interstellar turbulent motions. The regions studied are mostly gravitationally bound and in approximate virial equilibrium. However, they cannot have formed by simple gravitational collapse, and it appears likely that molecular clouds and their substructures have been created at least partly by processes of supersonic hydrodynamics. The hierarchy of subcondensations may terminate with objects so small that their internal motions are no longer supersonic; this predicts a minimum protostellar mass of the order of a few tenths of a solar mass. Massive 'protostellar' clumps always have supersonic internal motions and will therefore develop complex internal structures, probably leading to the formation of many pre-stellar condensation nuclei that grow by accretion to produce the final stellar mass spectrum. Molecular clouds must be transient structures, and are probably dispersed after not much more than 10 7 yr. (author)

Observations and Measurements on Unsteady Cloud Cavitation Flow Structures

International Nuclear Information System (INIS)

Gu, L X; Yan, G J; Huang, B

2015-01-01

The objectives of this paper are to investigate the unsteady structures and hydrodynamics of cavitating flows. Experimental results are presented for a Clark-Y hydrofoil, which is fixed at α=0°, 5° and 8°. The high-speed video camera and Particle Image Velocimetry (PIV) are applied to investigate the transient flow structures. The dynamic measurement system is used to record the dynamic characteristics. The cloud cavitation exhibits noticeable unsteady characteristics. For the case of α=0°, there exit strong interactions between the attached cavity and the re-entrant flow. While for the case of α=8°, the re-entrant flow is relatively thin and the interaction between the cavity and re-entrant flow is limited. The results also present that the periodic collapse and shedding of the large-scale cloud cavitation, which leads to substantial increase of turbulent velocity fluctuations in the cavity region. Experimental evidence indicates that the hydrodynamics are clearly affected by the cavitating flow structures, the amplitude of load fluctuation are much higher for the cloud cavitating cases. (paper)

Observations and Measurements on Unsteady Cloud Cavitation Flow Structures

Science.gov (United States)

Gu, L. X.; Yan, G. J.; Huang, B.

2015-12-01

The objectives of this paper are to investigate the unsteady structures and hydrodynamics of cavitating flows. Experimental results are presented for a Clark-Y hydrofoil, which is fixed at α=0°, 5° and 8°. The high-speed video camera and Particle Image Velocimetry (PIV) are applied to investigate the transient flow structures. The dynamic measurement system is used to record the dynamic characteristics. The cloud cavitation exhibits noticeable unsteady characteristics. For the case of α=0°, there exit strong interactions between the attached cavity and the re-entrant flow. While for the case of α=8°, the re-entrant flow is relatively thin and the interaction between the cavity and re-entrant flow is limited. The results also present that the periodic collapse and shedding of the large-scale cloud cavitation, which leads to substantial increase of turbulent velocity fluctuations in the cavity region. Experimental evidence indicates that the hydrodynamics are clearly affected by the cavitating flow structures, the amplitude of load fluctuation are much higher for the cloud cavitating cases.

Photoionization-regulated star formation and the structure of molecular clouds

Science.gov (United States)

Mckee, Christopher F.

1989-01-01

A model for the rate of low-mass star formation in Galactic molecular clouds and for the influence of this star formation on the structure and evolution of the clouds is presented. The rate of energy injection by newly formed stars is estimated, and the effect of this energy injection on the size of the cloud is determined. It is shown that the observed rate of star formation appears adequate to support the observed clouds against gravitational collapse. The rate of photoionization-regulated star formation is estimated and it is shown to be in agreement with estimates of the observed rate of star formation if the observed molecular cloud parameters are used. The mean cloud extinction and the Galactic star formation rate per unit mass of molecular gas are predicted theoretically from the condition that photionization-regulated star formation be in equilibrium. A simple model for the evolution of isolated molecular clouds is developed.

Internal structure and stability of an interstellar cloud heated by an external flux of soft X-rays

International Nuclear Information System (INIS)

Sabano, Yutaka; Tosa, Makoto

1975-01-01

We study the properties of an interstellar gas cloud which is heated by an external flux of soft X-rays and has a uniform pressure distribution. The heating flux is significantly attenuated inside the cloud even for a rather small cloud, and the central region of the cloud is much cooler and denser than that heated uniformly, hence the cloud can be compressed easier. The stability of such a gas cloud and its implications for the process of star formation are discussed on the basis of the two-phase model of the interstellar medium. The large scale galactic shock seems important as a triggering mechanism for the formation of a dense cloud and for the gravitational collapse leading to star formation. (author)

FOREIGN EXPERIENCE OF USING CLOUD SERVICES FOR THE INFORMATION-ANALYTICAL SUPPORT OF THE ORGANIZATION OF INTERNATIONAL COOPERATION OF UNIVERSITIES

Directory of Open Access Journals (Sweden)

Kravchenko A.

2017-12-01

Full Text Available Foreign experience of using cloud services for the information-analytical support of the organization of international cooperation of universities is presented in the article. The best practices of using cloud services like new analytical tools and platforms for solving complex problems of optimization of the management of scientific and international activities of universities are analyzed. Architecture of the cloud computing environment as a system is analysed; it consists of 4 blocks: hardware; infrastructure; platforms and applications and cloud taxonomy for the organization of the scientific, academic and international activities of the University support, as well as taxonomy of the main cloud technologies to support the University's academic and international activities. The activities of the leading universities of the world for 2016-2017 are monitored and the expert results of Quacquarelli Symonds specialists’ are presented according to the World University Ratings. The evaluation was carried out based on more than 50 different indicators, such as: academic reputation; employer's reputation; faculty / student rate; reference (quotation about the faculty; international correlation of faculties; international student rate; assessment of the quality of researches of scientists and determination of productivity of the university; number of quotes; graduate university rewards; assessment of teaching quality; employment opportunity; Internationalization, which includes statistical indicators for the number of foreign students styding at University; number of exchange students; number of international partnership Agreements with other universities; accessibility; the possibility of distance learning; social responsibility; innovation; art and culture; inclusiveness, etc.

THE DEPENDENCE OF PRESTELLAR CORE MASS DISTRIBUTIONS ON THE STRUCTURE OF THE PARENTAL CLOUD

International Nuclear Information System (INIS)

Parravano, Antonio; Sánchez, Néstor; Alfaro, Emilio J.

2012-01-01

The mass distribution of prestellar cores is obtained for clouds with arbitrary internal mass distributions using a selection criterion based on the thermal and turbulent Jeans mass and applied hierarchically from small to large scales. We have checked this methodology by comparing our results for a log-normal density probability distribution function with the theoretical core mass function (CMF) derived by Hennebelle and Chabrier, namely a power law at large scales and a log-normal cutoff at low scales, but our method can be applied to any mass distributions representing a star-forming cloud. This methodology enables us to connect the parental cloud structure with the mass distribution of the cores and their spatial distribution, providing an efficient tool for investigating the physical properties of the molecular clouds that give rise to the prestellar core distributions observed. Simulated fractional Brownian motion (fBm) clouds with the Hurst exponent close to the value H = 1/3 give the best agreement with the theoretical CMF derived by Hennebelle and Chabrier and Chabrier's system initial mass function. Likewise, the spatial distribution of the cores derived from our methodology shows a surface density of companions compatible with those observed in Trapezium and Ophiucus star-forming regions. This method also allows us to analyze the properties of the mass distribution of cores for different realizations. We found that the variations in the number of cores formed in different realizations of fBm clouds (with the same Hurst exponent) are much larger than the expected root N statistical fluctuations, increasing with H.

The International Symposium on Grids and Clouds

Science.gov (United States)

The International Symposium on Grids and Clouds (ISGC) 2012 will be held at Academia Sinica in Taipei from 26 February to 2 March 2012, with co-located events and workshops. The conference is hosted by the Academia Sinica Grid Computing Centre (ASGC). 2012 is the decennium anniversary of the ISGC which over the last decade has tracked the convergence, collaboration and innovation of individual researchers across the Asia Pacific region to a coherent community. With the continuous support and dedication from the delegates, ISGC has provided the primary international distributed computing platform where distinguished researchers and collaboration partners from around the world share their knowledge and experiences. The last decade has seen the wide-scale emergence of e-Infrastructure as a critical asset for the modern e-Scientist. The emergence of large-scale research infrastructures and instruments that has produced a torrent of electronic data is forcing a generational change in the scientific process and the mechanisms used to analyse the resulting data deluge. No longer can the processing of these vast amounts of data and production of relevant scientific results be undertaken by a single scientist. Virtual Research Communities that span organisations around the world, through an integrated digital infrastructure that connects the trust and administrative domains of multiple resource providers, have become critical in supporting these analyses. Topics covered in ISGC 2012 include: High Energy Physics, Biomedicine & Life Sciences, Earth Science, Environmental Changes and Natural Disaster Mitigation, Humanities & Social Sciences, Operations & Management, Middleware & Interoperability, Security and Networking, Infrastructure Clouds & Virtualisation, Business Models & Sustainability, Data Management, Distributed Volunteer & Desktop Grid Computing, High Throughput Computing, and High Performance, Manycore & GPU Computing.

International Symposium on Grids and Clouds (ISGC) 2014

Science.gov (United States)

The International Symposium on Grids and Clouds (ISGC) 2014 will be held at Academia Sinica in Taipei, Taiwan from 23-28 March 2014, with co-located events and workshops. The conference is hosted by the Academia Sinica Grid Computing Centre (ASGC).“Bringing the data scientist to global e-Infrastructures” is the theme of ISGC 2014. The last decade has seen the phenomenal growth in the production of data in all forms by all research communities to produce a deluge of data from which information and knowledge need to be extracted. Key to this success will be the data scientist - educated to use advanced algorithms, applications and infrastructures - collaborating internationally to tackle society’s challenges. ISGC 2014 will bring together researchers working in all aspects of data science from different disciplines around the world to collaborate and educate themselves in the latest achievements and techniques being used to tackle the data deluge. In addition to the regular workshops, technical presentations and plenary keynotes, ISGC this year will focus on how to grow the data science community by considering the educational foundation needed for tomorrow’s data scientist. Topics of discussion include Physics (including HEP) and Engineering Applications, Biomedicine & Life Sciences Applications, Earth & Environmental Sciences & Biodiversity Applications, Humanities & Social Sciences Application, Virtual Research Environment (including Middleware, tools, services, workflow, ... etc.), Data Management, Big Data, Infrastructure & Operations Management, Infrastructure Clouds and Virtualisation, Interoperability, Business Models & Sustainability, Highly Distributed Computing Systems, and High Performance & Technical Computing (HPTC).

A novel approach for introducing cloud spatial structure into cloud radiative transfer parameterizations

Science.gov (United States)

Huang, Dong; Liu, Yangang

2014-12-01

Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Although some parameterizations started to address the issue of subgrid variability by introducing a subgrid probability distribution function for relevant quantities, the spatial structure has been typically ignored and thus the subgrid-scale interactions cannot be accounted for physically. Here we present a new statistical-physics-like approach whereby the spatial autocorrelation function can be used to physically capture the net effects of subgrid cloud interaction with radiation. The new approach is able to faithfully reproduce the Monte Carlo 3D simulation results with several orders less computational cost, allowing for more realistic representation of cloud radiation interactions in large-scale models.

Investigation into electron cloud effects in the International Linear Collider positron damping ring

Energy Technology Data Exchange (ETDEWEB)

Crittenden, J. A.; Conway, J.; Dugan, G. F.; Palmer, M. A.; Rubin, D. L.; Shanks, J.; Sonnad, K. G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M. A.; Guiducci, S.; Pivi, M. T. F.; Wang, L.

2014-03-01

We report modeling results for electron cloud buildup and instability in the International Linear Collider positron damping ring. Updated optics, wiggler magnets, and vacuum chamber designs have recently been developed for the 5 GeV, 3.2-km racetrack layout. An analysis of the synchrotron radiation profile around the ring has been performed, including the effects of diffuse and specular photon scattering on the interior surfaces of the vacuum chamber. The results provide input to the cloud buildup simulations for the various magnetic field regions of the ring. The modeled cloud densities thus obtained are used in the instability threshold calculations. We conclude that the mitigation techniques employed in this model will suffice to allow operation of the damping ring at the design operational specifications

MEASURING THE FRACTAL STRUCTURE OF INTERSTELLAR CLOUDS

NARCIS (Netherlands)

VOGELAAR, MGR; WAKKER, BP

To study the structure of interstellar matter we have applied the concept of fractal curves to the brightness contours of maps of interstellar clouds and from these estimated the fractal dimension for some of them. We used the so-called perimeter-area relation as the basis for these estimates. We

MEASURING THE FRACTAL STRUCTURE OF INTERSTELLAR CLOUDS

NARCIS (Netherlands)

VOGELAAR, MGR; WAKKER, BP

1994-01-01

To study the structure of interstellar matter we have applied the concept of fractal curves to the brightness contours of maps of interstellar clouds and from these estimated the fractal dimension for some of them. We used the so-called perimeter-area relation as the basis for these estimates. We

Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

International Nuclear Information System (INIS)

Blumenthal, G.R.; Mathews, W.G.

1979-01-01

The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

Satellite-Observed Vertical Structures of Clouds over the Amazon Basin

Science.gov (United States)

Wu, M.; Lee, J. E.

2017-12-01

The long wet season of the Amazon basin currently plays a critical role in the terrestrial ecosystem, regulating carbon balance and supporting high biodiversity. It has been argued that the land surface processes are important in maintaining high precipitation; yet, how the land-atmosphere interactions modulate the atmospheric processes are not completely understood. As a first step toward solving this problem, here we examine the vertical structures of clouds and the thermodynamics of the atmosphere over the entire basin at the different time of the year. We combine the vertical distribution of cloud water content from CloudSat, and the atmospheric thermodynamic conditions from the ECMWF ERA-interim reanalysis to compare and contrast the atmospheric condition at different time of the year-the wet, dry, and dry-to-wet transition seasons-and in different regions-ever-wet evergreen broadleaf forests, wet evergreen broadleaf forests with a dry season, and dry wooded grasslands/woodlands-following water stress gradient. In the ever-wet and wet regions, a large amount of cloud ice water is present in the upper atmosphere (above 11km) and convective available potential energy (CAPE) is high during the transition season, supporting the claim that the convective activity is strongest during the transition season. In the dry region, there are more cloud water above 8km over woodlands than over wooded grasslands during the dry and transition seasons, indicating the influence of the land cover. We also classified our data following the large-scale circulation pattern, and the CloudSat data support more deep convective activities in the wet and dry regions when the wind blows from the east during the wet and transition seasons. As a next step, we will focus more on linking the cloud structure to the large-scale circulation and surface processes.

Investigation on HL-1M pellet shape and cloud structure

International Nuclear Information System (INIS)

Zheng Yinjia

2001-01-01

When hydrogen multi-pellet flied out from the gun exit and was injected into the HL-1M plasma, the pellet injection and ablation cloud were observed by using a 2D CCD camera SensiCam 360LF. The shape of flight pellet from the gun exit was obtained with the photos taken. The pellet ablation process and the structure of its cloud were analyzed by means of photos with multiple exposure (exp. 100 ns) and long exposure. The experimental setup is described, the results of the pellet injection experiment and characteristic of ablation cloud are presented

A novel approach for introducing cloud spatial structure into cloud radiative transfer parameterizations

International Nuclear Information System (INIS)

Huang, Dong; Liu, Yangang

2014-01-01

Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Although some parameterizations started to address the issue of subgrid variability by introducing a subgrid probability distribution function for relevant quantities, the spatial structure has been typically ignored and thus the subgrid-scale interactions cannot be accounted for physically. Here we present a new statistical-physics-like approach whereby the spatial autocorrelation function can be used to physically capture the net effects of subgrid cloud interaction with radiation. The new approach is able to faithfully reproduce the Monte Carlo 3D simulation results with several orders less computational cost, allowing for more realistic representation of cloud radiation interactions in large-scale models. (letter)

11th International Conference on P2P, Parallel, Grid, Cloud and Internet Computing

CERN Document Server

Barolli, Leonard; Amato, Flora

2017-01-01

P2P, Grid, Cloud and Internet computing technologies have been very fast established as breakthrough paradigms for solving complex problems by enabling aggregation and sharing of an increasing variety of distributed computational resources at large scale. The aim of this volume is to provide latest research findings, innovative research results, methods and development techniques from both theoretical and practical perspectives related to P2P, Grid, Cloud and Internet computing as well as to reveal synergies among such large scale computing paradigms. This proceedings volume presents the results of the 11th International Conference on P2P, Parallel, Grid, Cloud And Internet Computing (3PGCIC-2016), held November 5-7, 2016, at Soonchunhyang University, Asan, Korea.

Hurricane Satellite (HURSAT) from International Satellite Cloud Climatology Project (ISCCP) B1, Version 6

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Hurricane Satellite (HURSAT) from derived International Satellite Cloud Climatology Project (ISCCP) B1 observations of tropical cyclones worldwide. The B1 data...

A network approach to the geometric structure of shallow cloud fields

Science.gov (United States)

Glassmeier, F.; Feingold, G.

2017-12-01

The representation of shallow clouds and their radiative impact is one of the largest challenges for global climate models. While the bulk properties of cloud fields, including effects of organization, are a very active area of research, the potential of the geometric arrangement of cloud fields for the development of new parameterizations has hardly been explored. Self-organized patterns are particularly evident in the cellular structure of Stratocumulus (Sc) clouds so readily visible in satellite imagery. Inspired by similar patterns in biology and physics, we approach pattern formation in Sc fields from the perspective of natural cellular networks. Our network analysis is based on large-eddy simulations of open- and closed-cell Sc cases. We find the network structure to be neither random nor characteristic to natural convection. It is independent of macroscopic cloud fields properties like the Sc regime (open vs closed) and its typical length scale (boundary layer height). The latter is a consequence of entropy maximization (Lewis's Law with parameter 0.16). The cellular pattern is on average hexagonal, where non-6 sided cells occur according to a neighbor-number distribution variance of about 2. Reflecting the continuously renewing dynamics of Sc fields, large (many-sided) cells tend to neighbor small (few-sided) cells (Aboav-Weaire Law with parameter 0.9). These macroscopic network properties emerge independent of the Sc regime because the different processes governing the evolution of closed as compared to open cells correspond to topologically equivalent network dynamics. By developing a heuristic model, we show that open and closed cell dynamics can both be mimicked by versions of cell division and cell disappearance and are biased towards the expansion of smaller cells. This model offers for the first time a fundamental and universal explanation for the geometric pattern of Sc clouds. It may contribute to the development of advanced Sc parameterizations

Automatic Generation of Structural Building Descriptions from 3D Point Cloud Scans

DEFF Research Database (Denmark)

Ochmann, Sebastian; Vock, Richard; Wessel, Raoul

2013-01-01

We present a new method for automatic semantic structuring of 3D point clouds representing buildings. In contrast to existing approaches which either target the outside appearance like the facade structure or rather low-level geometric structures, we focus on the building’s interior using indoor...... scans to derive high-level architectural entities like rooms and doors. Starting with a registered 3D point cloud, we probabilistically model the affiliation of each measured point to a certain room in the building. We solve the resulting clustering problem using an iterative algorithm that relies...... on the estimated visibilities between any two locations within the point cloud. With the segmentation into rooms at hand, we subsequently determine the locations and extents of doors between adjacent rooms. In our experiments, we demonstrate the feasibility of our method by applying it to synthetic as well...

Automatic Generation of Structural Building Descriptions from 3D Point Cloud Scans

DEFF Research Database (Denmark)

Ochmann, Sebastian; Vock, Richard; Wessel, Raoul

2013-01-01

We present a new method for automatic semantic structuring of 3D point clouds representing buildings. In contrast to existing approaches which either target the outside appearance like the facade structure or rather low-level geometric structures, we focus on the building’s interior using indoor...... scans to derive high-level architectural entities like rooms and doors. Starting with a registered 3D point cloud, we probabilistically model the affiliation of each measured point to a certain room in the building. We solve the resulting clustering problem using an iterative algorithm that relies...

A COMPACT HIGH VELOCITY CLOUD NEAR THE MAGELLANIC STREAM: METALLICITY AND SMALL-SCALE STRUCTURE

Energy Technology Data Exchange (ETDEWEB)

Kumari, Nimisha [Ecole Polytechnique, Route de Saclay, F-91128 Palaiseau (France); Fox, Andrew J.; Tumlinson, Jason; Thom, Christopher; Ely, Justin [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Westmeier, Tobias [ICRAR, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia)

2015-02-10

The Magellanic Stream (MS) is a well-resolved gaseous tail originating from the Magellanic Clouds. Studies of its physical properties and chemical composition are needed to understand its role in Galactic evolution. We investigate the properties of a compact HVC (CHVC 224.0-83.4-197) lying close on the sky to the MS to determine whether it is physically connected to the Stream and to examine its internal structure. Our study is based on analysis of HST/COS spectra of three QSOs (Ton S210, B0120-28, and B0117-2837) all of which pass through this single cloud at small angular separation (≲0.°72), allowing us to compare physical conditions on small spatial scales. No significant variation is detected in the ionization structure from one part of the cloud to the other. Using Cloudy photoionization models, toward Ton S210 we derive elemental abundances of [C/H] = –1.21 ± 0.11, [Si/H] = –1.16 ± 0.11, [Al/H] = –1.19 ± 0.17, and [O/H] = –1.12 ± 0.22, which agree within 0.09 dex. The CHVC abundances match the 0.1 solar abundances measured along the main body of the Stream. This suggests that the CHVC (and by extension the extended network of filaments to which it belongs) has an origin in the MS. It may represent a fragment that has been removed from the Stream as it interacts with the gaseous Galactic halo.

DSaaS: A cloud service for persistent data structures

CSIR Research Space (South Africa)

Le Roux, PB

2016-04-01

Full Text Available 2CSIR/SU Centre for Artificial Intelligence Research pierrebleroux@gmail.com, kroon@sun.ac.za, whkbester@cs.sun.ac.za Keywords: DaaS, SaaS, Cloud Computing, Persistent Data Structure, Version...

Lost in Cloud

Science.gov (United States)

Maluf, David A.; Shetye, Sandeep D.; Chilukuri, Sri; Sturken, Ian

2012-01-01

Cloud computing can reduce cost significantly because businesses can share computing resources. In recent years Small and Medium Businesses (SMB) have used Cloud effectively for cost saving and for sharing IT expenses. With the success of SMBs, many perceive that the larger enterprises ought to move into Cloud environment as well. Government agency s stove-piped environments are being considered as candidates for potential use of Cloud either as an enterprise entity or pockets of small communities. Cloud Computing is the delivery of computing as a service rather than as a product, whereby shared resources, software, and information are provided to computers and other devices as a utility over a network. Underneath the offered services, there exists a modern infrastructure cost of which is often spread across its services or its investors. As NASA is considered as an Enterprise class organization, like other enterprises, a shift has been occurring in perceiving its IT services as candidates for Cloud services. This paper discusses market trends in cloud computing from an enterprise angle and then addresses the topic of Cloud Computing for NASA in two possible forms. First, in the form of a public Cloud to support it as an enterprise, as well as to share it with the commercial and public at large. Second, as a private Cloud wherein the infrastructure is operated solely for NASA, whether managed internally or by a third-party and hosted internally or externally. The paper addresses the strengths and weaknesses of both paradigms of public and private Clouds, in both internally and externally operated settings. The content of the paper is from a NASA perspective but is applicable to any large enterprise with thousands of employees and contractors.

Molecular clouds in the North American and Pelican Nebulae: structures

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shaobo; Xu, Ye; Yang, Ji, E-mail: shbzhang@pmo.ac.cn [Purple Mountain Observatory, and Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008 (China)

2014-03-01

We present observations of a 4.25 deg{sup 2} area toward the North American and Pelican Nebulae in the J = 1-0 transitions of {sup 12}CO, {sup 13}CO, and C{sup 18}O. Three molecules show different emission areas with their own distinct structures. These different density tracers reveal several dense clouds with a surface density of over 500 M {sub ☉} pc{sup –2} and a mean H{sub 2} column density of 5.8, 3.4, and 11.9 × 10{sup 21} cm{sup –2} for {sup 12}CO, {sup 13}CO, and C{sup 18}O, respectively. We obtain a total mass of 5.4 × 10{sup 4} M {sub ☉} ({sup 12}CO), 2.0 × 10{sup 4} M {sub ☉} ({sup 13}CO), and 6.1 × 10{sup 3} M {sub ☉} (C{sup 18}O) in the complex. The distribution of excitation temperature shows two phases of gas: cold gas (∼10 K) spreads across the whole cloud; warm gas (>20 K) outlines the edge of the cloud heated by the W80 H II region. The kinetic structure of the cloud indicates an expanding shell surrounding the ionized gas produced by the H II region. There are six discernible regions in the cloud: the Gulf of Mexico, Caribbean Islands and Sea, and Pelican's Beak, Hat, and Neck. The areas of {sup 13}CO emission range within 2-10 pc{sup 2} with mass of (1-5) × 10{sup 3} M {sub ☉} and line width of a few km s{sup –1}. The different line properties and signs of star-forming activity indicate they are in different evolutionary stages. Four filamentary structures with complicated velocity features are detected along the dark lane in LDN 935. Furthermore, a total of 611 molecular clumps within the {sup 13}CO tracing cloud are identified using the ClumpFind algorithm. The properties of the clumps suggest that most of the clumps are gravitationally bound and at an early stage of evolution with cold and dense molecular gas.

1 Vertical structure of orographic precipitating clouds observed over ...

Indian Academy of Sciences (India)

11

The present study explores the vertical structure of precipitating clouds associated with orographic features in South .... The PR, by design, detects PLW and not CLW. Dryness of ...... Organization of Asian Monsoon Convection*; J. Clim. 19(14) ...

Variability of oceanic deep convective system vertical structures observed by CloudSat in Indo-Pacific regions associated with the Madden-Julian oscillation

Science.gov (United States)

Yuan, Jian

2016-09-01

Vertical structures of deep convective systems during the Madden-Julian oscillation (MJO) are investigated using CloudSat radar measurements in Indo-Pacific oceanic areas. In active phases of the MJO, relatively more large systems and connected mesoscale convective systems (CMCSs) occur. The occurrence frequency of CMCSs peaks in the onset phase, a phase earlier than separated mesoscale convective systems (SMCSs). Compared with SMCSs, CMCSs of all sizes have weaker reflectivity above 8 km in their deep precipitating portions and thick anvil clouds closely linked to them, suggesting more "stratiform" physics associated with them. SMCSs and CMCSs together produce relatively the least anvil clouds in the onset phase, while their deep precipitating portions show stronger/weaker reflectivity above 8 km before/after the onset phase. Thus, after the onset phase of the MJO, mesoscale convective systems shift toward a more "convective" organization because SMCSs maximize after the onset, while their internal structures appear more stratiform because internally they have weaker reflectivity above 8 km. CMCSs coincide with a more humid middle troposphere spatially, even at the same locations a few days before they occur. Middle-tropospheric moistening peaks in the onset phase. Moistening of the free troposphere around deep convective systems shows relatively stronger moistening/drying below 700 hPa before/after the onset phase than domain-mean averages. Low-topped clouds occur most frequently around CMCSs and in active phases, consistent with the presence of a moister free troposphere. Coexistence of these phenomena suggests that the role of middle troposphere moisture in the formation of CMCSs should be better understood.

Tropical cloud and precipitation regimes as seen from near-simultaneous TRMM, CloudSat, and CALIPSO observations and comparison with ISCCP

Science.gov (United States)

Luo, Zhengzhao Johnny; Anderson, Ricardo C.; Rossow, William B.; Takahashi, Hanii

2017-06-01

Although Tropical Rainfall Measuring Mission (TRMM) and CloudSat/CALIPSO fly in different orbits, they frequently cross each other so that for the period between 2006 and 2010, a total of 15,986 intersect lines occurred within 20 min of each other from 30°S to 30°N, providing a rare opportunity to study tropical cloud and precipitation regimes and their internal vertical structure from near-simultaneous measurements by these active sensors. A k-means cluster analysis of TRMM and CloudSat matchups identifies three tropical cloud and precipitation regimes: the first two regimes correspond to, respectively, organized deep convection with heavy rain and cirrus anvils with moderate rain; the third regime is a convectively suppressed regime that can be further divided into three subregimes, which correspond to, respectively, stratocumulus clouds with drizzle, cirrus overlying low clouds, and nonprecipitating cumulus. Inclusion of CALIPSO data adds to the dynamic range of cloud properties and identifies one more cluster; subcluster analysis further identifies a thin, midlevel cloud regime associated with tropical mountain ranges. The radar-lidar cloud regimes are compared with the International Satellite Cloud Climatology Project (ISCCP) weather states (WSs) for the extended tropics. Focus is placed on the four convectively active WSs, namely, WS1-WS4. ISCCP WS1 and WS2 are found to be counterparts of Regime 1 and Regime 2 in radar-lidar observations, respectively. ISCCP WS3 and WS4, which are mainly isolated convection and broken, detached cirrus, do not have a strong association with any individual radar and lidar regimes, a likely effect of the different sampling strategies between ISCCP and active sensors and patchy cloudiness of these WSs.

Structure and characteristics of diffuse interstellar clouds

International Nuclear Information System (INIS)

Arshutkin, L.N.; Kolesnik, I.G.

1978-01-01

The results of model calculations for spherically symmetrical interstellar clouds being under external pressure are given. Thermal balance of gas clouds is considered. Ultraviolet radiation fields in clouds and equilibrium for chemical elements are calculated for this purpose. Calculations were carried out in the case when cooling is under way mainly by carbon atoms and ions. The clouds with mass up to 700 Msub(sun) under external pressure from 800 to 3000 K cm -3 are considered. In typical for Galactic disk conditions, clouds have dense n > or approximately 200 cm -3 , and cold T approximately 20-30 K state clouds depending on external pressure is given. The critical mass for clouds at the Galactic disk is approximately 500-600 Msub(sun). It is less than the isothermal solution by a factor of approximately 1.5. The massive gas-dust cloud formation problem is discussed

The cloud computational environment – a blueprint for applications in nuclear structure physics

International Nuclear Information System (INIS)

Mishev, S.

2013-01-01

The utility of the cloud computational model for studies in the field of the nuclear structure theory is addressed. In particular, a class of theoretical many-body approaches which could benefit from this technology is delineated. An architecture suitable for dealing with high performance computations for nuclear structure theories in a cloud is outlined. Alongside that, a nuclear theory aggregation software platform for presenting reports on calculations from various models is discussed. (author)

STRUCTURAL AND FUNCTIONAL MODEL OF CLOUD ORIENTED LEARNING ENVIRONMENT FOR BACHELORS OF INFORMATICS TRAINING

Directory of Open Access Journals (Sweden)

Tetiana A. Vakaliuk

2017-06-01

Full Text Available The article summarizes the essence of the category "model". There are presented the main types of models used in educational research: structural, functional, structural and functional model as well as basic requirements for building these types of models. The national experience in building models and designing cloud-based learning environment of educational institutions (both higher and secondary is analyzed. It is presented structural and functional model of cloud-based learning environment for Bachelor of Informatics. Also we describe each component of cloud-based learning environment model for bachelors of informatics training: target, managerial, organizational, content and methodical, communication, technological and productive. It is summarized, that COLE should solve all major tasks that relate to higher education institutions.

The Magellanic clouds

International Nuclear Information System (INIS)

1989-01-01

As the two galaxies nearest to our own, the Magellanic Clouds hold a special place in studies of the extragalactic distance scale, of stellar evolution and the structure of galaxies. In recent years, results from the South African Astronomical Observatory (SAAO) and elsewhere have shown that it is possible to begin understanding the three dimensional structure of the Clouds. Studies of Magellanic Cloud Cepheids have continued, both to investigate the three-dimensional structure of the Clouds and to learn more about Cepheids and their use as extragalactic distance indicators. Other research undertaken at SAAO includes studies on Nova LMC 1988 no 2 and red variables in the Magellanic Clouds

Cloud Infrastructure Security

OpenAIRE

Velev , Dimiter; Zlateva , Plamena

2010-01-01

Part 4: Security for Clouds; International audience; Cloud computing can help companies accomplish more by eliminating the physical bonds between an IT infrastructure and its users. Users can purchase services from a cloud environment that could allow them to save money and focus on their core business. At the same time certain concerns have emerged as potential barriers to rapid adoption of cloud services such as security, privacy and reliability. Usually the information security professiona...

Continued rise of the cloud advances and trends in cloud computing

CERN Document Server

Mahmood, Zaigham

2014-01-01

Cloud computing is no-longer a novel paradigm, but instead an increasingly robust and established technology, yet new developments continue to emerge in this area. Continued Rise of the Cloud: Advances and Trends in Cloud Computing captures the state of the art in cloud technologies, infrastructures, and service delivery and deployment models. The book provides guidance and case studies on the development of cloud-based services and infrastructures from an international selection of expert researchers and practitioners. A careful analysis is provided of relevant theoretical frameworks, prac

Variability of Oceanic Mesoscale Convective System Vertical Structures Observed by CloudSat in Indo-Pacific Regions Associated with the Madden-Julian Oscillation

Science.gov (United States)

Yuan, J.

2016-12-01

Vertical structures of mesoscale convective systems (MCSs) during the Madden-Julian-Oscillation (MJO) are investigated using 2006-2011 CloudSat radar measurements for Indo-Pacific oceanic areas. In active phases of the MJO relatively more large MCSs and connected MCSs occur. The frequency of occurrence of connected MCSs peaks in the onset phase, a phase earlier than separated MCSs. Compared to separated MCSs, connected MCSs in all sizes have weaker reflectivity above 8 km in their deep precipitating portions and thick anvil clouds closely linked to them, suggesting more "stratiform" physics associated with them. Separated MCSs and connected MCSs together produce relatively the least anvil clouds in the onset phase while their deep precipitating portions show stronger/weaker reflectivity above 8 km before/after the onset phase. Thus after the onset phase of the MJO, MCSs shift toward more "convective" organization because separated MCSs maximize after the onset, while their internal structures appear more "stratiform" because internally they have weaker reflectivity above 8km. Connected MCSs coincide with a more humid middle troposphere spatially, even at the same places a few days before they occur. Middle-tropospheric moistening peaks in the onset phase. Moistening of the free troposphere around deep convective systems shows relatively stronger moistening/drying below the 700 hPa before/after the onset phase compared to domain-mean averages. Lower-topped clouds occur most frequently around CMCSs and in active phases, consistent with the presence of a moister free troposphere. Coexistence of these phenomena suggests that the role of middle troposphere moisture in the formation of CMCSs needs to be better understood.

A simple model for the initial phase of a water plasma cloud about a large structure in space

International Nuclear Information System (INIS)

Hastings, D.E.; Gatsonis, N.A.; Mogstad, T.

1988-01-01

Large structures in the ionosphere will outgas or eject neutral water and perturb the ambient neutral environment. This water can undergo charge exchange with the ambient oxygen ions and form a water plasma cloud. Additionally, water dumps or thruster firings can create a water plasma cloud. A simple model for the evolution of a water plasma cloud about a large space structure is obtained. It is shown that if the electron density around a large space structure is substantially enhanced above the ambient density then the plasma cloud will move away from the structure. As the cloud moves away, it will become unstable and will eventually break up into filaments. A true steady state will exist only if the total electron density is unperturbed from the ambient density. When the water density is taken to be consistent with shuttle-based observations, the cloud is found to slowly drift away on a time scale of many tens of milliseconds. This time is consistent with the shuttle observations

Multiple scattering of light by water cloud droplets with external and internal mixing of black carbon aerosols

International Nuclear Information System (INIS)

Wang Hai-Hua; Sun Xian-Ming

2012-01-01

The mixture of water cloud droplets with black carbon impurities is modeled by external and internal mixing models. The internal mixing model is modeled with a two-layered sphere (water cloud droplets containing black carbon (BC) inclusions), and the single scattering and absorption characteristics are calculated at the visible wavelength of 0.55 μm by using the Lorenz—Mie theory. The external mixing model is developed assuming that the same amount of BC particles are mixed with the water droplets externally. The multiple scattering characteristics are computed by using the Monte Carlo method. The results show that when the size of the BC aerosol is small, the reflection intensity of the internal mixing model is bigger than that of the external mixing model. However, if the size of the BC aerosol is big, the absorption of the internal mixing model will be larger than that of the external mixing model. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

STRUCTURE LINE DETECTION FROM LIDAR POINT CLOUDS USING TOPOLOGICAL ELEVATION ANALYSIS

Directory of Open Access Journals (Sweden)

C. Y. Lo

2012-07-01

Full Text Available Airborne LIDAR point clouds, which have considerable points on object surfaces, are essential to building modeling. In the last two decades, studies have developed different approaches to identify structure lines using two main approaches, data-driven and modeldriven. These studies have shown that automatic modeling processes depend on certain considerations, such as used thresholds, initial value, designed formulas, and predefined cues. Following the development of laser scanning systems, scanning rates have increased and can provide point clouds with higher point density. Therefore, this study proposes using topological elevation analysis (TEA to detect structure lines instead of threshold-dependent concepts and predefined constraints. This analysis contains two parts: data pre-processing and structure line detection. To preserve the original elevation information, a pseudo-grid for generating digital surface models is produced during the first part. The highest point in each grid is set as the elevation value, and its original threedimensional position is preserved. In the second part, using TEA, the structure lines are identified based on the topology of local elevation changes in two directions. Because structure lines can contain certain geometric properties, their locations have small relieves in the radial direction and steep elevation changes in the circular direction. Following the proposed approach, TEA can be used to determine 3D line information without selecting thresholds. For validation, the TEA results are compared with those of the region growing approach. The results indicate that the proposed method can produce structure lines using dense point clouds.

Jupiter's Deep Cloud Structure Revealed Using Keck Observations of Spectrally Resolved Line Shapes

Science.gov (United States)

Bjoraker, G. L.; Wong, M.H.; de Pater, I.; Adamkovics, M.

2015-01-01

Technique: We present a method to determine the pressure at which significant cloud opacity is present between 2 and 6 bars on Jupiter. We use: a) the strength of a Fraunhofer absorption line in a zone to determine the ratio of reflected sunlight to thermal emission, and b) pressure- broadened line profiles of deuterated methane (CH3D) at 4.66 meters to determine the location of clouds. We use radiative transfer models to constrain the altitude region of both the solar and thermal components of Jupiter's 5-meter spectrum. Results: For nearly all latitudes on Jupiter the thermal component is large enough to constrain the deep cloud structure even when upper clouds are present. We find that Hot Spots, belts, and high latitudes have broader line profiles than do zones. Radiative transfer models show that Hot Spots in the North and South Equatorial Belts (NEB, SEB) typically do not have opaque clouds at pressures greater than 2 bars. The South Tropical Zone (STZ) at 32 degrees South has an opaque cloud top between 4 and 5 bars. From thermochemical models this must be a water cloud. We measured the variation of the equivalent width of CH3D with latitude for comparison with Jupiter's belt-zone structure. We also constrained the vertical profile of H2O in an SEB Hot Spot and in the STZ. The Hot Spot is very dry for a probability less than 4.5 bars and then follows the H2O profile observed by the Galileo Probe. The STZ has a saturated H2O profile above its cloud top between 4 and 5 bars.

Revised cloud storage structure for light-weight data archiving in LHD

International Nuclear Information System (INIS)

Nakanishi, Hideya; Masaki, Ohsuna; Mamoru, Kojima; Setsuo, Imazu; Miki, Nonomura; Masahiko, Emoto; Takashi, Yamamoto; Yoshio, Nagayama; Takahisa, Ozeki; Noriyoshi, Nakajima; Katsumi, Ida; Osamu, Kaneko

2014-01-01

Highlights: • GlusterFS is adopted to replace IznaStor cloud storage in LHD. • GlusterFS and OpenStack/Swift are compared. • SSD-based GlusterFS distributed replicated volume is separated from normal RAID storage. • LABCOM system changes the storage technology every 4 years for cost efficiency. - Abstract: The LHD data archiving system has newly selected GlusterFS distributed filesystem for the replacement of the present cloud storage software named “IznaStor/dSS”. Even though the prior software provided many favorable functionalities of hot plug and play node insertion, internal auto-replication of data files, and symmetric load balancing between all member nodes, it revealed a poor feature in recovering from an accidental malfunction of a storage node. Once a failure happened, the recovering process usually took at least several days or sometimes more than a week with a heavy cpu load. In some cases they fell into the so-called “split-brain” or “amnesia” condition, not to get recovered from it. Since the recovery time tightly depends on the capacity size of the fault node, individual HDD management is more desirable than large volumes of HDD arrays. In addition, the dynamic mutual awareness of data location information may be removed if some other static data distribution method can be applied. In this study, the candidate middleware of “OpenStack/Swift” and “GlusterFS” has been tested by using the real mass of LHD data for more than half a year, and finally GlusterFS has been selected to replace the present IznaStor. It has implemented very limited functionalities of cloud storage but a simplified RAID10-like structure, which may consequently provide lighter-weight read/write ability. Since the LABCOM data system is implemented to be independent of the storage structure, it is easy to plug off the IznaStor and on the new GlusterFS. The effective I/O speed is also confirmed to be on the same level as the estimated one from raw

Revised cloud storage structure for light-weight data archiving in LHD

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Hideya, E-mail: nakanisi@nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Masaki, Ohsuna; Mamoru, Kojima; Setsuo, Imazu; Miki, Nonomura; Masahiko, Emoto; Takashi, Yamamoto; Yoshio, Nagayama [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Takahisa, Ozeki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Noriyoshi, Nakajima; Katsumi, Ida; Osamu, Kaneko [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan)

2014-05-15

Highlights: • GlusterFS is adopted to replace IznaStor cloud storage in LHD. • GlusterFS and OpenStack/Swift are compared. • SSD-based GlusterFS distributed replicated volume is separated from normal RAID storage. • LABCOM system changes the storage technology every 4 years for cost efficiency. - Abstract: The LHD data archiving system has newly selected GlusterFS distributed filesystem for the replacement of the present cloud storage software named “IznaStor/dSS”. Even though the prior software provided many favorable functionalities of hot plug and play node insertion, internal auto-replication of data files, and symmetric load balancing between all member nodes, it revealed a poor feature in recovering from an accidental malfunction of a storage node. Once a failure happened, the recovering process usually took at least several days or sometimes more than a week with a heavy cpu load. In some cases they fell into the so-called “split-brain” or “amnesia” condition, not to get recovered from it. Since the recovery time tightly depends on the capacity size of the fault node, individual HDD management is more desirable than large volumes of HDD arrays. In addition, the dynamic mutual awareness of data location information may be removed if some other static data distribution method can be applied. In this study, the candidate middleware of “OpenStack/Swift” and “GlusterFS” has been tested by using the real mass of LHD data for more than half a year, and finally GlusterFS has been selected to replace the present IznaStor. It has implemented very limited functionalities of cloud storage but a simplified RAID10-like structure, which may consequently provide lighter-weight read/write ability. Since the LABCOM data system is implemented to be independent of the storage structure, it is easy to plug off the IznaStor and on the new GlusterFS. The effective I/O speed is also confirmed to be on the same level as the estimated one from raw

Observations of Local Positive Low Cloud Feedback Patterns and Their Role in Internal Variability and Climate Sensitivity

Science.gov (United States)

Yuan, Tianle; Oreopoulos, Lazaros; Platnick, Steven E.; Meyer, Kerry

2018-05-01

Modeling studies have shown that cloud feedbacks are sensitive to the spatial pattern of sea surface temperature (SST) anomalies, while cloud feedbacks themselves strongly influence the magnitude of SST anomalies. Observational counterparts to such patterned interactions are still needed. Here we show that distinct large-scale patterns of SST and low-cloud cover (LCC) emerge naturally from objective analyses of observations and demonstrate their close coupling in a positive local SST-LCC feedback loop that may be important for both internal variability and climate change. The two patterns that explain the maximum amount of covariance between SST and LCC correspond to the Interdecadal Pacific Oscillation and the Atlantic Multidecadal Oscillation, leading modes of multidecadal internal variability. Spatial patterns and time series of SST and LCC anomalies associated with both modes point to a strong positive local SST-LCC feedback. In many current climate models, our analyses suggest that SST-LCC feedback strength is too weak compared to observations. Modeled local SST-LCC feedback strength affects simulated internal variability so that stronger feedback produces more intense and more realistic patterns of internal variability. To the extent that the physics of the local positive SST-LCC feedback inferred from observed climate variability applies to future greenhouse warming, we anticipate significant amount of delayed warming because of SST-LCC feedback when anthropogenic SST warming eventually overwhelm the effects of internal variability that may mute anthropogenic warming over parts of the ocean. We postulate that many climate models may be underestimating both future warming and the magnitude of modeled internal variability because of their weak SST-LCC feedback.

Radiation pressure - a stabilizing agent of dust clouds in comets?

International Nuclear Information System (INIS)

Froehlich, H.E.; Notni, P.

1988-01-01

The internal dynamics of an illuminated dust cloud of finite optical thickness is investigated. The dependence of the radiation pressure on the optical depth makes the individual particles oscillate, in one dimension, around the accelerated centre of gravity of the cloud. The cloud moves as an entity, irrespectively of the velocity dispersion of the particles and their efficiency for radiation pressure. If the optical depth does not change, i.e. if the cloud does not expand laterally, its lifetime is unlimited. A contraction caused by energy dissipation in mechanical collisions between the dust particles is expected. The range of particle sizes which can be transported by such a 'coherent cloud' is estimated, as well as the acceleration of the whole cloud. The structure of the cloud in real space and in velocity space is investigated. A comparison with the 'striae' observed in the dust tails of great comets shows that the parent clouds of these striae may have been of the kind considered. (author)

International Symposium on Grids and Clouds (ISGC) 2016

Science.gov (United States)

The International Symposium on Grids and Clouds (ISGC) 2016 will be held at Academia Sinica in Taipei, Taiwan from 13-18 March 2016, with co-located events and workshops. The conference is hosted by the Academia Sinica Grid Computing Centre (ASGC). The theme of ISGC 2016 focuses on“Ubiquitous e-infrastructures and Applications”. Contemporary research is impossible without a strong IT component - researchers rely on the existence of stable and widely available e-infrastructures and their higher level functions and properties. As a result of these expectations, e-Infrastructures are becoming ubiquitous, providing an environment that supports large scale collaborations that deal with global challenges as well as smaller and temporal research communities focusing on particular scientific problems. To support those diversified communities and their needs, the e-Infrastructures themselves are becoming more layered and multifaceted, supporting larger groups of applications. Following the call for the last year conference, ISGC 2016 continues its aim to bring together users and application developers with those responsible for the development and operation of multi-purpose ubiquitous e-Infrastructures. Topics of discussion include Physics (including HEP) and Engineering Applications, Biomedicine & Life Sciences Applications, Earth & Environmental Sciences & Biodiversity Applications, Humanities, Arts, and Social Sciences (HASS) Applications, Virtual Research Environment (including Middleware, tools, services, workflow, etc.), Data Management, Big Data, Networking & Security, Infrastructure & Operations, Infrastructure Clouds and Virtualisation, Interoperability, Business Models & Sustainability, Highly Distributed Computing Systems, and High Performance & Technical Computing (HPTC), etc.

A TRUSTWORTHY CLOUD FORENSICS ENVIRONMENT

OpenAIRE

Zawoad , Shams; Hasan , Ragib

2015-01-01

Part 5: CLOUD FORENSICS; International audience; The rapid migration from traditional computing and storage models to cloud computing environments has made it necessary to support reliable forensic investigations in the cloud. However, current cloud computing environments often lack support for forensic investigations and the trustworthiness of evidence is often questionable because of the possibility of collusion between dishonest cloud providers, users and forensic investigators. This chapt...

November 17-18, 1975: A clue to an internal structure of magnetic clouds?

Czech Academy of Sciences Publication Activity Database

Vandas, Marek; Geranios, A.

2001-01-01

Roč. 106, A2 (2001), s. 1849-1858 ISSN 0148-0227 R&D Projects: GA ČR GA205/99/1712; GA AV ČR KSK1042603; GA MŠk ME 183 Institutional research plan: CEZ:AV0Z1003909 Keywords : magnetic cloud s * coronal mass ejections * interplanetary magnetic filed Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.609, year: 2001

The Cloud-Aerosol Transport System (CATS): A New Lidar for Aerosol and Cloud Profiling from the International Space Station

Science.gov (United States)

Welton, Ellsworth J.; McGill, Mathew J.; Yorks. John E.; Hlavka, Dennis L.; Hart, William D.; Palm, Stephen P.; Colarco, Peter R.

2012-01-01

Spaceborne lidar profiling of aerosol and cloud layers has been successfully implemented during a number of prior missions, including LITE, ICESat, and CALIPSO. Each successive mission has added increased capability and further expanded the role of these unique measurements in wide variety of applications ranging from climate, to air quality, to special event monitoring (ie, volcanic plumes). Many researchers have come to rely on the availability of profile data from CALIPSO, especially data coincident with measurements from other A-Train sensors. The CALIOP lidar on CALIPSO continues to operate well as it enters its fifth year of operations. However, active instruments have more limited lifetimes than their passive counterparts, and we are faced with a potential gap in lidar profiling from space if the CALIOP lidar fails before a new mission is operational. The ATLID lidar on EarthCARE is not expected to launch until 2015 or later, and the lidar component of NASA's proposed Aerosols, Clouds, and Ecosystems (ACE) mission would not be until after 2020. Here we present a new aerosol and cloud lidar that was recently selected to provide profiling data from the International Space Station (ISS) starting in 2013. The Cloud-Aerosol Transport System (CATS) is a three wavelength (1064,532,355 nm) elastic backscatter lidar with HSRL capability at 532 nm. Depolarization measurements will be made at all wavelengths. The primary objective of CATS is to continue the CALIPSO aerosol and cloud profile data record, ideally with overlap between both missions and EarthCARE. In addition, the near real time (NRT) data capability ofthe ISS will enable CATS to support operational applications such as aerosol and air quality forecasting and special event monitoring. The HSRL channel will provide a demonstration of technology and a data testbed for direct extinction retrievals in support of ACE mission development. An overview of the instrument and mission will be provided, along with a

The fourth International Conference on Information Science and Cloud Computing

Science.gov (United States)

This book comprises the papers accepted by the fourth International Conference on Information Science and Cloud Computing (ISCC), which was held from 18-19 December, 2015 in Guangzhou, China. It has 70 papers divided into four parts. The first part focuses on Information Theory with 20 papers; the second part emphasizes Machine Learning also containing 21 papers; in the third part, there are 21 papers as well in the area of Control Science; and the last part with 8 papers is dedicated to Cloud Science. Each part can be used as an excellent reference by engineers, researchers and students who need to build a knowledge base of the most current advances and state-of-practice in the topics covered by the ISCC conference. Special thanks go to Professor Deyu Qi, General Chair of ISCC 2015, for his leadership in supervising the organization of the entire conference; Professor Tinghuai Ma, Program Chair, and members of program committee for evaluating all the submissions and ensuring the selection of only the highest quality papers; and the authors for sharing their ideas, results and insights. We sincerely hope that you enjoy reading papers included in this book.

Orion infrared nebula/molecular cloud

International Nuclear Information System (INIS)

Zuckerman, B.; Palmer, P.

1975-01-01

Observational and theoretical studies of the Orion Nebula and the associated molecular clouds have greatly increased our understanding of this and other regions in which star formation is taking place. Fundamental questions remain unanswered; and in this Letter we address three of them: (1) the chemical composition of the molecular cloud, (2) its internal motions, and (3) the role of magnetic fields in its evolution. We show that the gas phase chemistry and internal motions in one part of the cloud are distinctly different from those in the rest of the cloud, and two recent estimates of the magnetic field strengths are very uncertain. (auth)

Lidar studies of extinction in clouds in the ECLIPS project

International Nuclear Information System (INIS)

Martin, C.; Platt, R.; Young, S.A.; Patterson, G.P.

1992-01-01

The Experimental Cloud Lidar Pilot Study (ECLIPS) project has now had two active phases in 1989 and 1991. A number of laboratories around the world have taken part in the study. The observations have yielded new data on cloud height and structure, and have yielded some useful new information on the retrieval of cloud optical properties, together with the uncertainties involved. Clouds have a major impact on the climate of the earth. They have the effect of reducing the mean surface temperature from 30 C for a cloudless planet to a value of about 15 C for present cloud conditions. However, it is not at all certain how clouds would react to a change in the planetary temperature in the event of climate change due to a radiative forcing from greenhouse gases. Clouds both reflect out sunlight (negative feedback) and enhance the greenhouse effect (positive feedback), but the ultimate sign of cloud feedback is unknown. Because of these uncertainties, campaigns to study clouds intensely were initiated. The International Satellite Cloud Climatology (ISCPP) and the FIRE Campaigns (cirrus and stratocumulus) are examples. The ECLIPS was set up similarly to the above experiments to obtain information specifically on cloud base, but also cloud top (where possible), optical properties, and cloud structure. ECLIPS was designed to allow as many laboratories as possible globally to take part to get the largest range of clouds. It involves observations with elastic backscatter lidar, supported by infrared fluxes at the ground and radiosonde data, as basic instrumentation. More complex experiments using beam filter radiometers, solar pyranometers, and satellite data and often associated with other campaigns were also encouraged to join ECLIPS

pCloud: A Cloud-based Power Market Simulation Environment

Energy Technology Data Exchange (ETDEWEB)

Rudkevich, Aleksandr; Goldis, Evgeniy

2012-12-02

. - Competitive pricing structure, which will make high-volume usage of simulation services affordable. - Availability and affordability of high quality power simulators, which presently only large corporate clients can afford, will level the playing field in developing regional energy policies, determining prudent cost recovery mechanisms and assuring just and reasonable rates to consumers. - Users that presently do not have the resources to internally maintain modeling capabilities will now be able to run simulations. This will invite more players into the industry, ultimately leading to more transparent and liquid power markets.

Structural and parameteric uncertainty quantification in cloud microphysics parameterization schemes

Science.gov (United States)

van Lier-Walqui, M.; Morrison, H.; Kumjian, M. R.; Prat, O. P.; Martinkus, C.

2017-12-01

Atmospheric model parameterization schemes employ approximations to represent the effects of unresolved processes. These approximations are a source of error in forecasts, caused in part by considerable uncertainty about the optimal value of parameters within each scheme -- parameteric uncertainty. Furthermore, there is uncertainty regarding the best choice of the overarching structure of the parameterization scheme -- structrual uncertainty. Parameter estimation can constrain the first, but may struggle with the second because structural choices are typically discrete. We address this problem in the context of cloud microphysics parameterization schemes by creating a flexible framework wherein structural and parametric uncertainties can be simultaneously constrained. Our scheme makes no assuptions about drop size distribution shape or the functional form of parametrized process rate terms. Instead, these uncertainties are constrained by observations using a Markov Chain Monte Carlo sampler within a Bayesian inference framework. Our scheme, the Bayesian Observationally-constrained Statistical-physical Scheme (BOSS), has flexibility to predict various sets of prognostic drop size distribution moments as well as varying complexity of process rate formulations. We compare idealized probabilistic forecasts from versions of BOSS with varying levels of structural complexity. This work has applications in ensemble forecasts with model physics uncertainty, data assimilation, and cloud microphysics process studies.

The International Satellite Cloud Climatology Project H-Series climate data record product

Science.gov (United States)

Young, Alisa H.; Knapp, Kenneth R.; Inamdar, Anand; Hankins, William; Rossow, William B.

2018-03-01

This paper describes the new global long-term International Satellite Cloud Climatology Project (ISCCP) H-series climate data record (CDR). The H-series data contain a suite of level 2 and 3 products for monitoring the distribution and variation of cloud and surface properties to better understand the effects of clouds on climate, the radiation budget, and the global hydrologic cycle. This product is currently available for public use and is derived from both geostationary and polar-orbiting satellite imaging radiometers with common visible and infrared (IR) channels. The H-series data currently span July 1983 to December 2009 with plans for continued production to extend the record to the present with regular updates. The H-series data are the longest combined geostationary and polar orbiter satellite-based CDR of cloud properties. Access to the data is provided in network common data form (netCDF) and archived by NOAA's National Centers for Environmental Information (NCEI) under the satellite Climate Data Record Program (https://doi.org/10.7289/V5QZ281S" target="_blank">https://doi.org/10.7289/V5QZ281S). The basic characteristics, history, and evolution of the dataset are presented herein with particular emphasis on and discussion of product changes between the H-series and the widely used predecessor D-series product which also spans from July 1983 through December 2009. Key refinements included in the ISCCP H-series CDR are based on improved quality control measures, modified ancillary inputs, higher spatial resolution input and output products, calibration refinements, and updated documentation and metadata to bring the H-series product into compliance with existing standards for climate data records.

A Variational Method to Retrieve the Extinction Profile in Liquid Clouds Using Multiple Field-of-View Lidar

Science.gov (United States)

Pounder, Nicola L.; Hogan, Robin J.; Varnai, Tamas; Battaglia, Alessandro; Cahalan, Robert F.

2011-01-01

While liquid clouds playa very important role in the global radiation budget, it's been very difficult to remotely determine their internal cloud structure. Ordinary lidar instruments (similar to radars but using visible light pulses) receive strong signals from such clouds, but the information is limited to a thin layer near the cloud boundary. Multiple field-of-view (FOV) lidars offer some new hope as they are able to isolate photons that were scattered many times by cloud droplets and penetrated deep into a cloud before returning to the instrument. Their data contains new information on cloud structure, although the lack of fast simulation methods made it challenging to interpret the observations. This paper describes a fast new technique that can simulate multiple-FOV lidar signals and can even estimate the way the signals would change in response to changes in cloud properties-an ability that allows quick refinements in our initial guesses of cloud structure. Results for a hypothetical airborne three-FOV lidar suggest that this approach can help determine cloud structure for a deeper layer in clouds, and can reliably determine the optical thickness of even fairly thick liquid clouds. The algorithm is also applied to stratocumulus observations by the 8-FOV airborne "THOR" lidar. These tests demonstrate that the new method can determine the depth to which a lidar provides useful information on vertical cloud structure. This work opens the way to exploit data from spaceborne lidar and radar more rigorously than has been possible up to now.

Evaluating cloudiness in an AGCM with Cloud Vertical Structure classes and their radiative effects

Science.gov (United States)

Lee, D.; Cho, N.; Oreopoulos, L.; Barahona, D.

2017-12-01

Clouds are recognized not only as the main modulator of Earth's Radiation Budget but also as the atmospheric constituent carrying the largest uncertainty in future climate projections. The presentation will showcase a new framework for evaluating clouds and their radiative effects in Atmospheric Global Climate Models (AGCMs) using Cloud Vertical Structure (CVS) classes. We take advantage of a new CVS reference dataset recently created from CloudSat's 2B-CLDCLASS-LIDAR product and which assigns observed cloud vertical configurations to nine simplified CVS classes based on cloud co-occurrence in three standard atmospheric layers. These CVS classes can also be emulated in GEOS-5 using the subcolumn cloud generator currently paired with the RRTMG radiation package as an implementation of the McICA scheme. Comparisons between the observed and modeled climatologies of the frequency of occurrence of the various CVS classes provide a new vantage point for assessing the realism of GEOS-5 clouds. Furthermore, a comparison between observed and modeled cloud radiative effects according to their CVS is also possible thanks to the availability of CloudSat's 2B-FLXHR-LIDAR product and our ability to composite radiative fluxes by CVS class - both in the observed and modeled realm. This latter effort enables an investigation of whether the contribution of the various CVS classes to the Earth's radiation budget is represented realistically in GEOS-5. Making this new pathway of cloud evaluation available to the community is a major step towards the improved representation of clouds in climate models.

Cloud computing patterns fundamentals to design, build, and manage cloud applications

CERN Document Server

Fehling, Christoph; Retter, Ralph; Schupeck, Walter; Arbitter, Peter

2014-01-01

The current work provides CIOs, software architects, project managers, developers, and cloud strategy initiatives with a set of architectural patterns that offer nuggets of advice on how to achieve common cloud computing-related goals. The cloud computing patterns capture knowledge and experience in an abstract format that is independent of concrete vendor products. Readers are provided with a toolbox to structure cloud computing strategies and design cloud application architectures. By using this book cloud-native applications can be implemented and best suited cloud vendors and tooling for i

Cloud Computing:Strategies for Cloud Computing Adoption

OpenAIRE

Shimba, Faith

2010-01-01

The advent of cloud computing in recent years has sparked an interest from different organisations, institutions and users to take advantage of web applications. This is a result of the new economic model for the Information Technology (IT) department that cloud computing promises. The model promises a shift from an organisation required to invest heavily for limited IT resources that are internally managed, to a model where the organisation can buy or rent resources that are managed by a clo...

Jovian cloud structure from 5-mu M images

Science.gov (United States)

Ortiz, J. L.; Moreno, F.; Molina, A.; Roos-Serote, M.; Orton, G. S.

1999-09-01

Most radiative transfer studies place the cloud clearings responsible for the 5-mu m bright areas at pressure levels greater than 1.5 bar whereas the low-albedo clouds are placed at lower pressure levels, in the so-called ammonia cloud. If this picture is correct, and assuming that the strong vertical shear of the zonal wind detected by the Galileo Entry Probe exists at all latitudes in Jupiter, the bright areas at 5 mu m should drift faster than the dark clouds, which is not observed. At the Galileo Probe Entry latitude this can be explained by a wave, but this is not a likely explanation for all regions where the anticorrelation between 5-mu m brightness and red-nIR reflectivity is observed. Therefore, either the vertical zonal wind shears are not global or cloud clearings and dark clouds are located at the same pressure level. We have developed a multiple scattering radiative transfer code to model the limb-darkening at several jovian features derived from IRTF 4.8-mu m images, in order to retrieve information on the cloud levels. The limb darkening coefficients range from 1.4 at hot spots to 0.58 at the Equatorial Region. We also find that reflected light is dominant over thermal emission in the Equatorial Region, as already pointed out by other investigators. Preliminary results from our code tend to favor the idea that the ammonia cloud is a very high-albedo cloud with little influence on the contrast seen in the red and nIR and that a deeper cloud at P >1.5 bar can be responsible for the cloud clearings and for the low-albedo features simultaneously. This research was supported by the Comision Interministerial de Ciencia y Tecnologia under contract ESP96-0623.

Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method.

Science.gov (United States)

Shen, Yueqian; Lindenbergh, Roderik; Wang, Jinhu

2016-12-24

A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis.

Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method

Directory of Open Access Journals (Sweden)

Yueqian Shen

2016-12-01

Full Text Available A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis.

Cloud Computing Value Chains: Understanding Businesses and Value Creation in the Cloud

Science.gov (United States)

Mohammed, Ashraf Bany; Altmann, Jörn; Hwang, Junseok

Based on the promising developments in Cloud Computing technologies in recent years, commercial computing resource services (e.g. Amazon EC2) or software-as-a-service offerings (e.g. Salesforce. com) came into existence. However, the relatively weak business exploitation, participation, and adoption of other Cloud Computing services remain the main challenges. The vague value structures seem to be hindering business adoption and the creation of sustainable business models around its technology. Using an extensive analyze of existing Cloud business models, Cloud services, stakeholder relations, market configurations and value structures, this Chapter develops a reference model for value chains in the Cloud. Although this model is theoretically based on porter's value chain theory, the proposed Cloud value chain model is upgraded to fit the diversity of business service scenarios in the Cloud computing markets. Using this model, different service scenarios are explained. Our findings suggest new services, business opportunities, and policy practices for realizing more adoption and value creation paths in the Cloud.

Cloud type comparisons of AIRS, CloudSat, and CALIPSO cloud height and amount

Directory of Open Access Journals (Sweden)

B. H. Kahn

2008-03-01

Full Text Available The precision of the two-layer cloud height fields derived from the Atmospheric Infrared Sounder (AIRS is explored and quantified for a five-day set of observations. Coincident profiles of vertical cloud structure by CloudSat, a 94 GHz profiling radar, and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO, are compared to AIRS for a wide range of cloud types. Bias and variability in cloud height differences are shown to have dependence on cloud type, height, and amount, as well as whether CloudSat or CALIPSO is used as the comparison standard. The CloudSat-AIRS biases and variability range from −4.3 to 0.5±1.2–3.6 km for all cloud types. Likewise, the CALIPSO-AIRS biases range from 0.6–3.0±1.2–3.6 km (−5.8 to −0.2±0.5–2.7 km for clouds ≥7 km (<7 km. The upper layer of AIRS has the greatest sensitivity to Altocumulus, Altostratus, Cirrus, Cumulonimbus, and Nimbostratus, whereas the lower layer has the greatest sensitivity to Cumulus and Stratocumulus. Although the bias and variability generally decrease with increasing cloud amount, the ability of AIRS to constrain cloud occurrence, height, and amount is demonstrated across all cloud types for many geophysical conditions. In particular, skill is demonstrated for thin Cirrus, as well as some Cumulus and Stratocumulus, cloud types infrared sounders typically struggle to quantify. Furthermore, some improvements in the AIRS Version 5 operational retrieval algorithm are demonstrated. However, limitations in AIRS cloud retrievals are also revealed, including the existence of spurious Cirrus near the tropopause and low cloud layers within Cumulonimbus and Nimbostratus clouds. Likely causes of spurious clouds are identified and the potential for further improvement is discussed.

Molecular clouds and galactic spiral structure

International Nuclear Information System (INIS)

Dame, T.M.

1984-02-01

Galactic CO line emission at 115 GHz was surveyed in order to study the distribution of molecular clouds in the inner galaxy. Comparison of this survey with similar H1 data reveals a detailed correlation with the most intense 21 cm features. To each of the classical 21 cm H1 spiral arms of the inner galaxy there corresponds a CO molecular arm which is generally more clearly defined and of higher contrast. A simple model is devised for the galactic distribution of molecular clouds. The modeling results suggest that molecular clouds are essentially transient objects, existing for 15 to 40 million years after their formation in a spiral arm, and are largely confined to spiral features about 300 pc wide

Giant molecular cloud collisions as triggers of star formation. VI. Collision-induced turbulence

Science.gov (United States)

Wu, Benjamin; Tan, Jonathan C.; Nakamura, Fumitaka; Christie, Duncan; Li, Qi

2018-05-01

We investigate collisions between giant molecular clouds (GMCs) as potential generators of their internal turbulence. Using magnetohydrodynamic (MHD) simulations of self-gravitating, magnetized, turbulent GMCs, we compare kinematic and dynamic properties of dense gas structures formed when such clouds collide compared to those that form in non-colliding clouds as self-gravity overwhelms decaying turbulence. We explore the nature of turbulence in these structures via distribution functions of density, velocity dispersions, virial parameters, and momentum injection. We find that the dense clumps formed from GMC collisions have higher effective Mach number, greater overall velocity dispersions, sustain near-virial equilibrium states for longer times, and are the conduit for the injection of turbulent momentum into high density gas at high rates.

A flattened cloud core in NGC 2024

Science.gov (United States)

Ho, Paul T. P.; Peng, Yun-Lou; Torrelles, Jose M.; Gomez, Jose F.; Rodriguez, Luis F.; Canto, Jorge

1993-01-01

The (J, K) (1, 1) and (2, 2) NH3 lines were mapped toward a molecular cloud core in NGC 2024 using the VLA in its C/D-configuration. This region is associated with one of the most highly collimated molecular outflows. We find that the molecular condensations associated with the far-infrared sources FIR 5, FIR 6, and FIR 7 have kinetic temperatures of about 40 K. We also find line broadening toward FIR 6 and FIR 7. This suggests that these condensations may not be protostars heated by gravitational energy released during collapse but that they have an internal heating source. A flattened structure of ammonia emission is found extending parallel to the unipolar CO outflow structure, but displaced systematically to the east. If the NH3 emission traces the denser gas environment, there is no evidence that a dense gas structure is confining the molecular outflow. Instead, the location of the high-velocity outflow along the surface of the NH3 structure suggests that a wind is sweeping material from the surface of this elongated cloud core.

Near Real Time Vertical Profiles of Clouds and Aerosols from the Cloud-Aerosol Transport System (CATS) on the International Space Station

Science.gov (United States)

Yorks, J. E.; McGill, M. J.; Nowottnick, E. P.

2015-12-01

Plumes from hazardous events, such as ash from volcanic eruptions and smoke from wildfires, can have a profound impact on the climate system, human health and the economy. Global aerosol transport models are very useful for tracking hazardous plumes and predicting the transport of these plumes. However aerosol vertical distributions and optical properties are a major weakness of global aerosol transport models, yet a key component of tracking and forecasting smoke and ash. The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar designed to provide vertical profiles of clouds and aerosols while also demonstrating new in-space technologies for future Earth Science missions. CATS has been operating on the Japanese Experiment Module - Exposed Facility (JEM-EF) of the International Space Station (ISS) since early February 2015. The ISS orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three-day repeat cycle. The ISS orbit also provides CATS with excellent coverage over the primary aerosol transport tracks, mid-latitude storm tracks, and tropical convection. Data from CATS is used to derive properties of clouds and aerosols including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The measurements of atmospheric clouds and aerosols provided by the CATS payload have demonstrated several science benefits. CATS provides near-real-time observations of cloud and aerosol vertical distributions that can be used as inputs to global models. The infrastructure of the ISS allows CATS data to be captured, transmitted, and received at the CATS ground station within several minutes of data collection. The CATS backscatter and vertical feature mask are part of a customized near real time (NRT) product that the CATS processing team produces within 6 hours of collection. The continuous near real time CATS data

Clouds and the Near-Earth Environment: Possible Links

Directory of Open Access Journals (Sweden)

Condurache-Bota Simona

2015-12-01

Full Text Available Climate variability is a hot topic not only for scientists and policy-makers, but also for each and every one of us. The anthropogenic activities are considered to be responsible for most climate change, however there are large uncertainties about the magnitude of effects of solar variability and other extraterrestrial influences, such as galactic cosmic rays on terrestrial climate. Clouds play an important role due to feedbacks of the radiation budget: variation of cloud cover/composition affects climate, which, in turn, affects cloud cover via atmospheric dynamics and sea temperature variations. Cloud formation and evolution are still under scientific scrutiny, since their microphysics is still not understood. Besides atmospheric dynamics and other internal climatic parameters, extraterrestrial sources of cloud cover variation are considered. One of these is the solar wind, whose effect on cloud cover might be modulated by the global atmospheric electrical circuit. Clouds height and composition, their seasonal variation and latitudinal distribution should be considered when trying to identify possible mechanisms by which solar energy is transferred to clouds. The influence of the solar wind on cloud formation can be assessed also through the ap index - the geomagnetic storm index, which can be readily connected with interplanetary magnetic field, IMF structure. This paper proposes to assess the possible relationship between both cloud cover and solar wind proxies, as the ap index, function of cloud height and composition and also through seasonal studies. The data covers almost three solar cycles (1984-2009. Mechanisms are looked for by investigating observed trends or correlation at local/seasonal scale

Dynamics of magnetic clouds in interplanetary space

International Nuclear Information System (INIS)

Yeh, T.

1987-01-01

Magnetic clouds observed in interplanetary space may be regarded as extraneous bodies immersed in the magnetized medium of the solar wind. The interface between a magnetic cloud and its surrounding medium separates the internal and external magnetic fields. Polarization currents are induced in the peripheral layer to make the ambient magnetic field tangential. The motion of a magnetic cloud through the interplanetary medium may be partitioned into a translational motion of the magnetic cloud as a whole and an expansive motion of the volume relative to the axis of the magnetic cloud. The translational motion is determined by two kinds of forces, i.e., the gravitational force exerted by the Sun, and the hydromagnetic buoyancy force exerted by the surrounding medium. On the other hand, the expansive motion is determined by the pressure gradient sustaining the gross difference between the internal and external pressures and by the self-induced magnetic force that results from the interaction among the internal currents. The force resulting from the internal and external currents is a part of the hydromagnetic buoyancy force, manifested by a thermal stress caused by the inhomogeneity of the ambient magnetic pressure

Dynamics of magnetic clouds in interplanetary space

Science.gov (United States)

Yeh, Tyan

1987-09-01

Magnetic clouds observed in interplanetary space may be regarded as extraneous bodies immersed in the magnetized medium of the solar wind. The interface between a magnetic cloud and its surrounding medium separates the internal and external magnetic fields. Polarization currents are induced in the peripheral layer to make the ambient magnetic field tangential. The motion of a magnetic cloud through the interplanetary medium may be partitioned into a translational motion of the magnetic cloud as a whole and an expansive motion of the volume relative to the axis of the magnetic cloud. The translational motion is determined by two kinds of forces, i.e., the gravitational force exerted by the Sun, and the hydromagnetic buoyancy force exerted by the surrounding medium. On the other hand, the expansive motion is determined by the pressure gradient sustaining the gross difference between the internal and external pressures and by the self-induced magnetic force that results from the interaction among the internal currents. The force resulting from the internal and external currents is a part of the hydromagnetic buoyancy force, manifested by a thermal stress caused by the inhomogeneity of the ambient magnetic pressure.

More Than Filaments and Cores: Statistical Study of Structure Formation and Dynamics in Nearby Molecular Clouds

Science.gov (United States)

Chen, How-Huan; Goodman, Alyssa

2018-01-01

In the past decade, multiple attempts at understanding the connection between filaments and star forming cores have been made using observations across the entire epectrum. However, the filaments and the cores are usually treated as predefined--and well-defined--entities, instead of structures that often come at different sizes, shapes, with substantially different dynamics, and inter-connected at different scales. In my dissertation, I present an array of studies using different statistical methods, including the dendrogram and the probability distribution function (PDF), of structures at different size scales within nearby molecular clouds. These structures are identified using observations of different density tracers, and where possible, in the multi-dimensional parameter space of key dynamic properties--the LSR velocity, the velocity dispersion, and the column density. The goal is to give an overview of structure formation in nearby star-forming clouds, as well as of the dynamics in these structures. I find that the overall statistical properties of a larger structure is often the summation/superposition of sub-structures within, and that there could be significant variations due to local physical processes. I also find that the star formation process within molecular clouds could in fact take place in a non-monolithic manner, connecting potentially merging and/or transient structures, at different scales.

Development of a Cloud Computing-Based Pier Type Port Structure Stability Evaluation Platform Using Fiber Bragg Grating Sensors.

Science.gov (United States)

Jo, Byung Wan; Jo, Jun Ho; Khan, Rana Muhammad Asad; Kim, Jung Hoon; Lee, Yun Sung

2018-05-23

Structure Health Monitoring is a topic of great interest in port structures due to the ageing of structures and the limitations of evaluating structures. This paper presents a cloud computing-based stability evaluation platform for a pier type port structure using Fiber Bragg Grating (FBG) sensors in a system consisting of a FBG strain sensor, FBG displacement gauge, FBG angle meter, gateway, and cloud computing-based web server. The sensors were installed on core components of the structure and measurements were taken to evaluate the structures. The measurement values were transmitted to the web server via the gateway to analyze and visualize them. All data were analyzed and visualized in the web server to evaluate the structure based on the safety evaluation index (SEI). The stability evaluation platform for pier type port structures involves the efficient monitoring of the structures which can be carried out easily anytime and anywhere by converging new technologies such as cloud computing and FBG sensors. In addition, the platform has been successfully implemented at “Maryang Harbor” situated in Maryang-Meyon of Korea to test its durability.

Global Distribution and Vertical Structure of Clouds Revealed by CALIPSO

Science.gov (United States)

Yi, Y.; Minnis, P.; Winker, D.; Huang, J.; Sun-Mack, S.; Ayers, K.

2007-12-01

Understanding the effects of clouds on Earth's radiation balance, especially on longwave fluxes within the atmosphere, depends on having accurate knowledge of cloud vertical location within the atmosphere. The Cloud- Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite mission provides the opportunity to measure the vertical distribution of clouds at a greater detail than ever before possible. The CALIPSO cloud layer products from June 2006 to June 2007 are analyzed to determine the occurrence frequency and thickness of clouds as functions of time, latitude, and altitude. In particular, the latitude-longitude and vertical distributions of single- and multi-layer clouds and the latitudinal movement of cloud cover with the changing seasons are examined. The seasonal variablities of cloud frequency and geometric thickness are also analyzed and compared with similar quantities derived from the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) using the Clouds and the Earth's Radiant Energy System (CERES) cloud retrieval algorithms. The comparisons provide an estimate of the errors in cloud fraction, top height, and thickness incurred by passive algorithms.

Spatial and mass distributions of molecular clouds and spiral structure

International Nuclear Information System (INIS)

Kwan, J.; Valdes, F.; National Optical Astronomy Observatories, Tucson, AZ)

1987-01-01

The growth of molecular clouds resulting from cloud-cloud collisions and coalescence in the Galactic ring between 4 and 8 kpc are modeled, taking into account the presence of a spiral potential and the mutual cloud-cloud gravitational attraction. The mean lifetime of molecular clouds is determined to be about 200 million years. The clouds are present in both spiral arm and interarm regions, but a spiral pattern in their spatial distribution is clearly discernible, with the more massive clouds showing a stronger correlation with the spiral arms. As viewed from within the Galactic disk, however, it is very difficult to ascertain that the molecular cloud distribution in longitude-velocity space has a spiral pattern. 19 references

Ash cloud aviation advisories

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

1992-06-25

During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

CloudGC: Recycling Idle Virtual Machines in the Cloud

OpenAIRE

Zhang , Bo; Al-Dhuraibi , Yahya; Rouvoy , Romain; Paraiso , Fawaz; Seinturier , Lionel

2017-01-01

International audience; Cloud computing conveys the image of a pool of unlimited virtual resources that can be quickly and easily provisioned to accommodate the user requirements. However, this flexibility may require to adjust physical resources at the infrastructure level to keep the pace of user requests. While elasticity can be considered as the de facto solution to support this issue, this elasticity can still be broken by budget requirements or physical limitations of a private cloud. I...

a Point Cloud Classification Approach Based on Vertical Structures of Ground Objects

Science.gov (United States)

Zhao, Y.; Hu, Q.; Hu, W.

2018-04-01

This paper proposes a novel method for point cloud classification using vertical structural characteristics of ground objects. Since urbanization develops rapidly nowadays, urban ground objects also change frequently. Conventional photogrammetric methods cannot satisfy the requirements of updating the ground objects' information efficiently, so LiDAR (Light Detection and Ranging) technology is employed to accomplish this task. LiDAR data, namely point cloud data, can obtain detailed three-dimensional coordinates of ground objects, but this kind of data is discrete and unorganized. To accomplish ground objects classification with point cloud, we first construct horizontal grids and vertical layers to organize point cloud data, and then calculate vertical characteristics, including density and measures of dispersion, and form characteristic curves for each grids. With the help of PCA processing and K-means algorithm, we analyze the similarities and differences of characteristic curves. Curves that have similar features will be classified into the same class and point cloud correspond to these curves will be classified as well. The whole process is simple but effective, and this approach does not need assistance of other data sources. In this study, point cloud data are classified into three classes, which are vegetation, buildings, and roads. When horizontal grid spacing and vertical layer spacing are 3 m and 1 m respectively, vertical characteristic is set as density, and the number of dimensions after PCA processing is 11, the overall precision of classification result is about 86.31 %. The result can help us quickly understand the distribution of various ground objects.

INTERNATIONAL EXPERIENCE OF CLOUD ORIENTED LEARNING ENVIRONMENT DESIGN IN SECONDARY SCHOOLS

Directory of Open Access Journals (Sweden)

Svitlana G. Lytvynova

2014-06-01

Full Text Available The article highlights the foreign experience of designing of cloud oriented learning environments (COLE in general secondary education. The projects in Russia, Germany, Czech Republic, Australia, China, Israel, Africa, Singapore, Brazil, Egypt, Colombia and the United States are analyzed. The analysis of completed projects found out the common problems of implementing of cloud oriented learning environments (security of personal data, technical problems of integration of cloud environments with existing systems, and productivity of cloud services and their advantages for secondary education (mobility of participants, volumetric cloud data storage, universally accessibility, regular software updating, ease of use, etc..

GPU-Based Point Cloud Superpositioning for Structural Comparisons of Protein Binding Sites.

Science.gov (United States)

Leinweber, Matthias; Fober, Thomas; Freisleben, Bernd

2018-01-01

In this paper, we present a novel approach to solve the labeled point cloud superpositioning problem for performing structural comparisons of protein binding sites. The solution is based on a parallel evolution strategy that operates on large populations and runs on GPU hardware. The proposed evolution strategy reduces the likelihood of getting stuck in a local optimum of the multimodal real-valued optimization problem represented by labeled point cloud superpositioning. The performance of the GPU-based parallel evolution strategy is compared to a previously proposed CPU-based sequential approach for labeled point cloud superpositioning, indicating that the GPU-based parallel evolution strategy leads to qualitatively better results and significantly shorter runtimes, with speed improvements of up to a factor of 1,500 for large populations. Binary classification tests based on the ATP, NADH, and FAD protein subsets of CavBase, a database containing putative binding sites, show average classification rate improvements from about 92 percent (CPU) to 96 percent (GPU). Further experiments indicate that the proposed GPU-based labeled point cloud superpositioning approach can be superior to traditional protein comparison approaches based on sequence alignments.

Molecular clouds and galactic spiral structure

International Nuclear Information System (INIS)

Dame, T.M.

1983-01-01

Galactic CO line emission at 115 GHz has been surveyed in the region 12 0 less than or equal to l less than or equal to 60 0 and -1 0 less than or equal to b less than or equal to 1 0 in order to study the distribution of molecular clouds in the inner galaxy; an inner strip 0 0 .5 wide has been sampled every beamwidth (0 0 .125), the rest every two beamwidths. Comparison of the survey with similar HI data reveals a detailed correlation with the most intense 21-cm features, implying that the CO and HI trace the same galactic features and have the same large-scale kinematics. To each of the classical 21-cm (HI) spiral arms of the inner galaxy there corresponds a CO molecular arm which is generally more clearly defined and of higher contrast. A simple model is developed in which all of the CO emission from the inner galaxy arises from spiral arms. The modeling results suggest that molecular clouds are essentially transient objects, existing for 15 to 40 million years after their formation in a spiral arm, and are largely confined to spiral features about 300 pc wide. A variety of methods are employed to estimate distances and masses for the largest clouds detected by the inner-galaxy survey and a catalogue is compiled. The catalogued clouds, the largest of which have masses of several 10 6 M/sub sunmass/ and linear dimensions in excess of 100 pc, are found to be excellent spiral-arm tracers. One of the nearest of the clouds, that associated with the supernova remnant W44, is fully mapped in both CO and 13 CO and is discussed in detail

Computing patient data in the cloud: practical and legal considerations for genetics and genomics research in Europe and internationally.

Science.gov (United States)

Molnár-Gábor, Fruzsina; Lueck, Rupert; Yakneen, Sergei; Korbel, Jan O

2017-06-20

Biomedical research is becoming increasingly large-scale and international. Cloud computing enables the comprehensive integration of genomic and clinical data, and the global sharing and collaborative processing of these data within a flexibly scalable infrastructure. Clouds offer novel research opportunities in genomics, as they facilitate cohort studies to be carried out at unprecedented scale, and they enable computer processing with superior pace and throughput, allowing researchers to address questions that could not be addressed by studies using limited cohorts. A well-developed example of such research is the Pan-Cancer Analysis of Whole Genomes project, which involves the analysis of petabyte-scale genomic datasets from research centers in different locations or countries and different jurisdictions. Aside from the tremendous opportunities, there are also concerns regarding the utilization of clouds; these concerns pertain to perceived limitations in data security and protection, and the need for due consideration of the rights of patient donors and research participants. Furthermore, the increased outsourcing of information technology impedes the ability of researchers to act within the realm of existing local regulations owing to fundamental differences in the understanding of the right to data protection in various legal systems. In this Opinion article, we address the current opportunities and limitations of cloud computing and highlight the responsible use of federated and hybrid clouds that are set up between public and private partners as an adequate solution for genetics and genomics research in Europe, and under certain conditions between Europe and international partners. This approach could represent a sensible middle ground between fragmented individual solutions and a "one-size-fits-all" approach.

Cloud Computing: An Overview

Science.gov (United States)

Qian, Ling; Luo, Zhiguo; Du, Yujian; Guo, Leitao

In order to support the maximum number of user and elastic service with the minimum resource, the Internet service provider invented the cloud computing. within a few years, emerging cloud computing has became the hottest technology. From the publication of core papers by Google since 2003 to the commercialization of Amazon EC2 in 2006, and to the service offering of AT&T Synaptic Hosting, the cloud computing has been evolved from internal IT system to public service, from cost-saving tools to revenue generator, and from ISP to telecom. This paper introduces the concept, history, pros and cons of cloud computing as well as the value chain and standardization effort.

A STATISTICAL STUDY OF THE MASS AND DENSITY STRUCTURE OF INFRARED DARK CLOUDS

International Nuclear Information System (INIS)

Peretto, N.; Fuller, G. A.

2010-01-01

How and when the mass distribution of stars in the Galaxy is set is one of the main issues of modern astronomy. Here, we present a statistical study of mass and density distributions of infrared dark clouds (IRDCs) and fragments within them. These regions are pristine molecular gas structures and progenitors of stars and so provide insights into the initial conditions of star formation. This study makes use of an IRDC catalog, the largest sample of IRDC column density maps to date, containing a total of ∼11,000 IRDCs with column densities exceeding N H 2 = 1x10 22 cm -2 and over 50,000 single-peaked IRDC fragments. The large number of objects constitutes an important strength of this study, allowing a detailed analysis of the completeness of the sample and so statistically robust conclusions. Using a statistical approach to assigning distances to clouds, the mass and density distributions of the clouds and the fragments within them are constructed. The mass distributions show a steepening of the slope when switching from IRDCs to fragments, in agreement with previous results of similar structures. IRDCs and fragments are divided into unbound/bound objects by assuming Larson's relation and calculating their virial parameter. IRDCs are mostly gravitationally bound, while a significant fraction of the fragments are not. The density distribution of gravitationally unbound fragments shows a steep characteristic slope such as ΔN/Δlog(n) ∝ n -4.0±0.5 , rather independent of the range of fragment mass. However, the incompleteness limit at a number density of ∼10 3 cm -3 does not allow us to exclude a potential lognormal density distribution. In contrast, gravitationally bound fragments show a characteristic density peak at n ≅ 10 4 cm -3 but the shape of the density distributions changes with the range of fragment masses. An explanation for this could be the differential dynamical evolution of the fragment density with respect to their mass as more massive

Giant molecular cloud scaling relations: the role of the cloud definition

Science.gov (United States)

Khoperskov, S. A.; Vasiliev, E. O.; Ladeyschikov, D. A.; Sobolev, A. M.; Khoperskov, A. V.

2016-01-01

We investigate the physical properties of molecular clouds in disc galaxies with different morphologies: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our N-body/hydrodynamical simulations take into account non-equilibrium H2 and CO chemical kinetics, self-gravity, star formation and feedback processes. For the simulated galaxies, the scaling relations of giant molecular clouds, or so-called Larson's relations, are studied for two types of cloud definition (or extraction method): the first is based on total column density position-position (PP) data sets and the second is indicated by the CO (1-0) line emission used in position-position-velocity (PPV) data. We find that the cloud populations obtained using both cloud extraction methods generally have similar physical parameters, except that for the CO data the mass spectrum of clouds has a tail with low-mass objects M ˜ 103-104 M⊙. Owing toa varying column density threshold, the power-law indices in the scaling relations are significantly changed. In contrast, the relations are invariant to the CO brightness temperature threshold. Finally, we find that the mass spectra of clouds for PPV data are almost insensitive to the galactic morphology, whereas the spectra for PP data demonstrate significant variation.

X.509 Authentication/Authorization in FermiCloud

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyunwoo [Fermilab; Timm, Steven [Fermilab

2014-11-11

We present a summary of how X.509 authentication and authorization are used with OpenNebula in FermiCloud. We also describe a history of why the X.509 authentication was needed in FermiCloud, and review X.509 authorization options, both internal and external to OpenNebula. We show how these options can be and have been used to successfully run scientific workflows on federated clouds, which include OpenNebula on FermiCloud and Amazon Web Services as well as other community clouds. We also outline federation options being used by other commercial and open-source clouds and cloud research projects.

Simple structure diffusion cloud chamber for educational purpose

International Nuclear Information System (INIS)

Hrehuss, Gy.; Molnar, B.

1982-01-01

A simple structure diffusion cloud chamber was designed and built with educational aim. The source of alpha particles is Am-241 radioisotope smeared on steel foil, the source of vapor is a felt disc saturated with methanol. Five minutes after covering the chamber the system achieves the thermodynamic equilibrium and alpha particle tracks of 5 cm length become visible in the centre of the chamber. Life-time of a track is about 0.5-1 second, the frequency is 2-3 tracks/s. The presented diffusion chamber can be built simply and easily, using cheap common materials and components. (D.Gy.)

Detailed Information Security in Cloud Computing

OpenAIRE

Pavel Valerievich Ivonin

2013-01-01

The object of research in this article is technology of public clouds, structure and security system of clouds. Problems of information security in clouds are considered, elements of security system in public clouds are described.

Star formation induced by cloud-cloud collisions and galactic giant molecular cloud evolution

Science.gov (United States)

Kobayashi, Masato I. N.; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro; Fukui, Yasuo

2018-05-01

Recent millimeter/submillimeter observations towards nearby galaxies have started to map the whole disk and to identify giant molecular clouds (GMCs) even in the regions between galactic spiral structures. Observed variations of GMC mass functions in different galactic environments indicates that massive GMCs preferentially reside along galactic spiral structures whereas inter-arm regions have many small GMCs. Based on the phase transition dynamics from magnetized warm neutral medium to molecular clouds, Kobayashi et al. (2017, ApJ, 836, 175) proposes a semi-analytical evolutionary description for GMC mass functions including a cloud-cloud collision (CCC) process. Their results show that CCC is less dominant in shaping the mass function of GMCs than the accretion of dense H I gas driven by the propagation of supersonic shock waves. However, their formulation does not take into account the possible enhancement of star formation by CCC. Millimeter/submillimeter observations within the Milky Way indicate the importance of CCC in the formation of star clusters and massive stars. In this article, we reformulate the time-evolution equation largely modified from Kobayashi et al. (2017, ApJ, 836, 175) so that we additionally compute star formation subsequently taking place in CCC clouds. Our results suggest that, although CCC events between smaller clouds are more frequent than the ones between massive GMCs, CCC-driven star formation is mostly driven by massive GMCs ≳ 10^{5.5} M_{⊙} (where M⊙ is the solar mass). The resultant cumulative CCC-driven star formation may amount to a few 10 percent of the total star formation in the Milky Way and nearby galaxies.

Cloud computing and services science

NARCIS (Netherlands)

Ivanov, Ivan; van Sinderen, Marten J.; Shishkov, Boris

2012-01-01

This book is essentially a collection of the best papers of the International Conference on Cloud Computing and Services Science (CLOSER), which was held in Noordwijkerhout, The Netherlands on May 7–9, 2011. The conference addressed technology trends in the domain of cloud computing in relation to a

Implementation of a Parallel Protein Structure Alignment Service on Cloud

Directory of Open Access Journals (Sweden)

Che-Lun Hung

2013-01-01

Full Text Available Protein structure alignment has become an important strategy by which to identify evolutionary relationships between protein sequences. Several alignment tools are currently available for online comparison of protein structures. In this paper, we propose a parallel protein structure alignment service based on the Hadoop distribution framework. This service includes a protein structure alignment algorithm, a refinement algorithm, and a MapReduce programming model. The refinement algorithm refines the result of alignment. To process vast numbers of protein structures in parallel, the alignment and refinement algorithms are implemented using MapReduce. We analyzed and compared the structure alignments produced by different methods using a dataset randomly selected from the PDB database. The experimental results verify that the proposed algorithm refines the resulting alignments more accurately than existing algorithms. Meanwhile, the computational performance of the proposed service is proportional to the number of processors used in our cloud platform.

High energy physics and cloud computing

International Nuclear Information System (INIS)

Cheng Yaodong; Liu Baoxu; Sun Gongxing; Chen Gang

2011-01-01

High Energy Physics (HEP) has been a strong promoter of computing technology, for example WWW (World Wide Web) and the grid computing. In the new era of cloud computing, HEP has still a strong demand, and major international high energy physics laboratories have launched a number of projects to research on cloud computing technologies and applications. It describes the current developments in cloud computing and its applications in high energy physics. Some ongoing projects in the institutes of high energy physics, Chinese Academy of Sciences, including cloud storage, virtual computing clusters, and BESⅢ elastic cloud, are also described briefly in the paper. (authors)

The cloud security ecosystem technical, legal, business and management issues

CERN Document Server

Ko, Ryan

2015-01-01

Drawing upon the expertise of world-renowned researchers and experts, The Cloud Security Ecosystem comprehensively discusses a range of cloud security topics from multi-disciplinary and international perspectives, aligning technical security implementations with the most recent developments in business, legal, and international environments. The book holistically discusses key research and policy advances in cloud security - putting technical and management issues together with an in-depth treaties on a multi-disciplinary and international subject. The book features contributions from key tho

A boundary-layer cloud study using Southern Great Plains Cloud and radiation testbed (CART) data

Energy Technology Data Exchange (ETDEWEB)

Albrecht, B.; Mace, G.; Dong, X.; Syrett, W. [Pennsylvania State Univ., University Park, PA (United States)] [and others

1996-04-01

Boundary layer clouds-stratus and fairweather cumulus - are closely coupled involves the radiative impact of the clouds on the surface energy budget and the strong dependence of cloud formation and maintenance on the turbulent fluxes of heat and moisture in the boundary layer. The continuous data collection at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site provides a unique opportunity to study components of the coupling processes associated with boundary layer clouds and to provide descriptions of cloud and boundary layer structure that can be used to test parameterizations used in climate models. But before the CART data can be used for process studies and parameterization testing, it is necessary to evaluate and validate data and to develop techniques for effectively combining the data to provide meaningful descriptions of cloud and boundary layer characteristics. In this study we use measurements made during an intensive observing period we consider a case where low-level stratus were observed at the site for about 18 hours. This case is being used to examine the temporal evolution of cloud base, cloud top, cloud liquid water content, surface radiative fluxes, and boundary layer structure. A method for inferring cloud microphysics from these parameters is currently being evaluated.

Georeferenced Point Clouds: A Survey of Features and Point Cloud Management

Directory of Open Access Journals (Sweden)

Johannes Otepka

2013-10-01

Full Text Available This paper presents a survey of georeferenced point clouds. Concentration is, on the one hand, put on features, which originate in the measurement process themselves, and features derived by processing the point cloud. On the other hand, approaches for the processing of georeferenced point clouds are reviewed. This includes the data structures, but also spatial processing concepts. We suggest a categorization of features into levels that reflect the amount of processing. Point clouds are found across many disciplines, which is reflected in the versatility of the literature suggesting specific features.

Cloud prediction of protein structure and function with PredictProtein for Debian.

Science.gov (United States)

Kaján, László; Yachdav, Guy; Vicedo, Esmeralda; Steinegger, Martin; Mirdita, Milot; Angermüller, Christof; Böhm, Ariane; Domke, Simon; Ertl, Julia; Mertes, Christian; Reisinger, Eva; Staniewski, Cedric; Rost, Burkhard

2013-01-01

We report the release of PredictProtein for the Debian operating system and derivatives, such as Ubuntu, Bio-Linux, and Cloud BioLinux. The PredictProtein suite is available as a standard set of open source Debian packages. The release covers the most popular prediction methods from the Rost Lab, including methods for the prediction of secondary structure and solvent accessibility (profphd), nuclear localization signals (predictnls), and intrinsically disordered regions (norsnet). We also present two case studies that successfully utilize PredictProtein packages for high performance computing in the cloud: the first analyzes protein disorder for whole organisms, and the second analyzes the effect of all possible single sequence variants in protein coding regions of the human genome.

The photoevaporation of interstellar clouds

International Nuclear Information System (INIS)

Bertoldi, F.

1989-01-01

The dynamics of the photoevaporation of interstellar clouds and its consequences for the structure and evolution of H II regions are studied. An approximate analytical solution for the evolution of photoevaporating clouds is derived under the realistic assumption of axisymmetry. The effects of magnetic fields are taken into account in an approximate way. The evolution of a neutral cloud subjected to the ionizing radiation of an OB star has two distinct stages. When a cloud is first exposed to the radiation, the increase in pressure due to the ionization at the surface of the cloud leads to a radiation-driven implosion: an ionization front drives a shock into the cloud, ionizes part of it and compresses the remaining into a dense globule. The initial implosion is followed by an equilibrium cometary stage, in which the cloud maintains a semistationary comet-shaped configuration; it slowly evaporates while accelerating away from the ionizing star until the cloud has been completely ionized, reaches the edge of the H II region, or dies. Expressions are derived for the cloud mass-loss rate and acceleration. To investigate the effect of the cloud photoevaporation on the structure of H II regions, the evolution of an ensemble of clouds of a given mass distribution is studied. It is shown that the compressive effect of the ionizing radiation can induce star formation in clouds that were initially gravitationally stable, both for thermally and magnetically supported clouds

Can CFMIP2 models reproduce the leading modes of cloud vertical structure in the CALIPSO-GOCCP observations?

Science.gov (United States)

Wang, Fang; Yang, Song

2018-02-01

Using principal component (PC) analysis, three leading modes of cloud vertical structure (CVS) are revealed by the GCM-Oriented CALIPSO Cloud Product (GOCCP), i.e. tropical high, subtropical anticyclonic and extratropical cyclonic cloud modes (THCM, SACM and ECCM, respectively). THCM mainly reflect the contrast between tropical high clouds and clouds in middle/high latitudes. SACM is closely associated with middle-high clouds in tropical convective cores, few-cloud regimes in subtropical anticyclonic clouds and stratocumulus over subtropical eastern oceans. ECCM mainly corresponds to clouds along extratropical cyclonic regions. Models of phase 2 of Cloud Feedback Model Intercomparison Project (CFMIP2) well reproduce the THCM, but SACM and ECCM are generally poorly simulated compared to GOCCP. Standardized PCs corresponding to CVS modes are generally captured, whereas original PCs (OPCs) are consistently underestimated (overestimated) for THCM (SACM and ECCM) by CFMIP2 models. The effects of CVS modes on relative cloud radiative forcing (RSCRF/RLCRF) (RSCRF being calculated at the surface while RLCRF at the top of atmosphere) are studied in terms of principal component regression method. Results show that CFMIP2 models tend to overestimate (underestimated or simulate the opposite sign) RSCRF/RLCRF radiative effects (REs) of ECCM (THCM and SACM) in unit global mean OPC compared to observations. These RE biases may be attributed to two factors, one of which is underestimation (overestimation) of low/middle clouds (high clouds) (also known as stronger (weaker) REs in unit low/middle (high) clouds) in simulated global mean cloud profiles, the other is eigenvector biases in CVS modes (especially for SACM and ECCM). It is suggested that much more attention should be paid on improvement of CVS, especially cloud parameterization associated with particular physical processes (e.g. downwelling regimes with the Hadley circulation, extratropical storm tracks and others), which

Comparison of the Cloud Morphology Spatial Structure Between Jupiter and Saturn Using JunoCam and Cassini ISS

Science.gov (United States)

Garland, Justin; Sayanagi, Kunio M.; Blalock, John J.; Gunnarson, Jacob; McCabe, Ryan M.; Gallego, Angelina; Hansen, Candice; Orton, Glenn S.

2017-10-01

We present an analysis of the spatial-scales contained in the cloud morphology of Jupiter’s southern high latitudes using images captured by JunoCam in 2016 and 2017, and compare them to those on Saturn using images captured using the Imaging Science Subsystem (ISS) on board the Cassini orbiter. For Jupiter, the characteristic spatial scale of cloud morphology as a function of latitude is calculated from images taken in three visual (600-800, 500-600, 420-520 nm) bands and a near-infrared (880- 900 nm) band. In particular, we analyze the transition from the banded structure characteristic of Jupiter’s mid-latitudes to the chaotic structure of the polar region. We apply similar analysis to Saturn using images captured using Cassini ISS. In contrast to Jupiter, Saturn maintains its zonally organized cloud morphology from low latitudes up to the poles, culminating in the cyclonic polar vortices centered at each of the poles. By quantifying the differences in the spatial scales contained in the cloud morphology, our analysis will shed light on the processes that control the banded structures on Jupiter and Saturn. Our work has been supported by the following grants: NASA PATM NNX14AK07G, NASA MUREP NNX15AQ03A, and NSF AAG 1212216.

Vertical structure of orographic precipitating clouds observed over ...

Indian Academy of Sciences (India)

Shailendra Kumar

2017-11-23

Nov 23, 2017 ... the highest over the Western Ghats and the eastern Arabian Sea. ... Shallow clouds; mixed phase clouds; TRMM PR; Western Ghats; radar reflectivity. ..... The focus in the present work is on iden- ... A similar behaviour, but at.

Two-dimensional positive column structure with dust cloud: Experiment and nonlocal kinetic simulation

Science.gov (United States)

Zobnin, A. V.; Usachev, A. D.; Petrov, O. F.; Fortov, V. E.; Thoma, M. H.; Fink, M. A.

2018-03-01

The influence of a dust cloud on the structure of the positive column of a direct current gas discharge in a cylindrical glass tube under milligravity conditions has been studied both experimentally and numerically. The discharge was produced in neon at 60 Pa in a glass tube with a diameter of 30 mm at a discharge current 1 mA. Spherical monodisperse melamine formaldehyde dust particles with a diameter of 6.86 μm were injected into the positive column and formed there a uniform dust cloud with a maximum diameter of 14.4 mm. The shape of the cloud and the dust particle number density were measured. The cloud was stationary in the radial direction and slowly drifted in the axial direction. It was found that in the presence of the dust cloud, the intensity of the neon spectral line with a wavelength by 585.25 nm emitted by the discharge plasma increased by 2.3 times and 2 striations appeared on the anode side of the cloud. A numerical simulation of the discharge was performed using the 2D (quasi-3D) nonlocal self-consistent kinetic model of a longitudinally inhomogeneous axially symmetric positive column [Zobnin et al., Phys. Plasmas 21, 113503 (2014)], which was supplemented by a program module performing a self-consistent calculation of dust particle charges, the plasma recombination rate on dust particles, and ion scattering on dust particles. A new approach to the calculation of particle charges and the screening radius in dense dust clouds is proposed. The results of the simulation are presented, compared with experimental data and discussed. It is demonstrated that for the best agreement between simulated and experimental data, it is necessary to take into account the reflection of electrons from the dust particle surface in order to correctly describe the recombination rate in the cloud, its radial stability, and the dust particle charges.

Thin Cloud Detection Method by Linear Combination Model of Cloud Image

Science.gov (United States)

Liu, L.; Li, J.; Wang, Y.; Xiao, Y.; Zhang, W.; Zhang, S.

2018-04-01

The existing cloud detection methods in photogrammetry often extract the image features from remote sensing images directly, and then use them to classify images into cloud or other things. But when the cloud is thin and small, these methods will be inaccurate. In this paper, a linear combination model of cloud images is proposed, by using this model, the underlying surface information of remote sensing images can be removed. So the cloud detection result can become more accurate. Firstly, the automatic cloud detection program in this paper uses the linear combination model to split the cloud information and surface information in the transparent cloud images, then uses different image features to recognize the cloud parts. In consideration of the computational efficiency, AdaBoost Classifier was introduced to combine the different features to establish a cloud classifier. AdaBoost Classifier can select the most effective features from many normal features, so the calculation time is largely reduced. Finally, we selected a cloud detection method based on tree structure and a multiple feature detection method using SVM classifier to compare with the proposed method, the experimental data shows that the proposed cloud detection program in this paper has high accuracy and fast calculation speed.

Cloud Computing Governance Lifecycle

Directory of Open Access Journals (Sweden)

Soňa Karkošková

2016-06-01

Full Text Available Externally provisioned cloud services enable flexible and on-demand sourcing of IT resources. Cloud computing introduces new challenges such as need of business process redefinition, establishment of specialized governance and management, organizational structures and relationships with external providers and managing new types of risk arising from dependency on external providers. There is a general consensus that cloud computing in addition to challenges brings many benefits but it is unclear how to achieve them. Cloud computing governance helps to create business value through obtain benefits from use of cloud computing services while optimizing investment and risk. Challenge, which organizations are facing in relation to governing of cloud services, is how to design and implement cloud computing governance to gain expected benefits. This paper aims to provide guidance on implementation activities of proposed Cloud computing governance lifecycle from cloud consumer perspective. Proposed model is based on SOA Governance Framework and consists of lifecycle for implementation and continuous improvement of cloud computing governance model.

The structure of the Orion A molecular cloud

International Nuclear Information System (INIS)

Gerola, H.; Sofia, S.

1975-01-01

A consistent model of the Orion A molecular cloud is obtained by making use of the observed brightness temperature distributions of the J=2→1 and the J=1→0 transitions of the CO molecule, and the central component (F=2→1) of the J=1→0 transition of HCN, as well as the observed line profiles of the J=2→1 transition of CO, and the J=1→0 transition of HCN. The modeling is accomplished by fitting simultaneously all of these observations through solutions of the coupled equations of statistical equilibrium and radiative transfer for a spherical cloud having a kinetic temperature gradient, and different density and velocity distributions. We find that Orion A is strongly gravitationally bound and contracting, and that it can maintain the observed temperature distribution only by virtue of internal energy sources other than the contraction. This last conclusion is reached by computing the radiative losses due to the CO and HD cooling, as well as the losses due to the CO and HD cooling, as well as the losses due to inelastic collisions between the gas and the dust. Our results show that while the contraction rate is just about sufficient to balance the rate of radiation by CO, it is less than one-tenth of the rate at which energy is radiated by HD, and less than 0.001 of that at which energy could be lost to cool grains through totally inelastic collisions

Molecular Cloud Structures and Massive Star Formation in N159

Science.gov (United States)

Nayak, O.; Meixner, M.; Fukui, Y.; Tachihara, K.; Onishi, T.; Saigo, K.; Tokuda, K.; Harada, R.

2018-02-01

The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar objects (YSOs) that include 10 newly identified YSOs based on our search. We use dendrogram analysis to identify properties of the molecular clumps, such as flux, mass, linewidth, size, and virial parameter. We relate the YSO properties to the molecular gas properties. We find that the CS gas clumps have a steeper size–linewidth relation than the 12CO or 13CO gas clumps. This larger slope could potentially occur if the CS gas is tracing shocks. The virial parameters of the 13CO gas clumps in N159W and N159E are low (<1). The threshold for massive star formation in N159W is 501 M ⊙ pc‑2, and the threshold for massive star formation in N159E is 794 M ⊙ pc‑2. We find that 13CO is more photodissociated in N159E than N159W. The most massive YSO in N159E has cleared out a molecular gas hole in its vicinity. All the massive YSO candidates in N159E have a more evolved spectral energy distribution type in comparison to the YSO candidates in N159W. These differences lead us to conclude that the giant molecular cloud complex in N159E is more evolved than the giant molecular cloud complex in N159W.

Studies of the Structure of C Pellet Ablation Clouds in W7-AS

International Nuclear Information System (INIS)

Bakhareva, O.A.; Sergeev, V.Yu.; Kuteev, B.V.; Skokov, V.G.; Timokhin, V.M.; Burhenn, R.

2005-01-01

The structure of the ablation clouds surrounding carbon pellets injected into the ECR-heated Wendelstein 7-AS plasma has been studied. Snapshot and integrated photographs obtained in the spectral ranges containing the CII (720 ± 5 nm and 723 ± 1 nm) and CIII (770 ± 5 nm) spectral lines were analyzed over a wide range of the bulk plasma parameters. It is found that the cloud luminosity profile along the magnetic field is exponential with either one or two characteristic decay lengths of about a few millimeters and a few centimeters. The smaller length corresponds to the zone closer to the pellet. There is good agreement between the characteristic decay lengths deduced from snapshot and integrated photographs. The characteristic decay lengths were obtained along the entire pellet trajectory and were found to change weakly in the central region and to grow at the plasma periphery (generally, in inverse proportion to the plasma electron density). In the central region, the characteristic decay lengths are about a few millimeters and 1 cm. They depend weakly on the bulk plasma temperature and decrease with increasing bulk plasma density. These lengths agree fairly well with estimates of the ionization length of carbon ions into the C 2+ , C 3+ , and C 4+ charge states, respectively, assuming that ionization is provided by the hot electrons of the bulk plasma and that the cloud expands with the ion-acoustic velocity at a temperature of ∼1 eV. The results obtained prove that the cloud structure in the vicinity of the pellet is mainly determined by the bulk plasma electrons

Cloud structure evolution of heavy rain events from the East-West Pacific Ocean: a combined global observation analysis

Science.gov (United States)

Sekaranom, A. B.; Nurjani, E.; Pujiastuti, I.

2018-04-01

Heavy rain events are often associated with flood hazards as one of the most devastating events across the globe. It is therefore essential to identify the evolution of heavy rainfall cloud structures, primarily from global satellite observation, as a tool to provide better disaster early warning systems. To identify the mechanism of heavy rainfall systems and its relationship with cloud development, especially over The Pacific Ocean, we aim to study the westward evolution of the convective systems over this area. Several datasets from Tropical Rainfall Measuring Mission (TRMM), CloudSat GEOPROF product, and ECMWF-reanalysis (ERA) interim were utilized to characterize the evolution. Geolocation and orbital time-lag analysis of the three different datasets for more than 8 years (2006-2014) could provide information related to the evolution of cloud structures associated with heavy rain events. In the first step, a heavy rainfall database was generated from TRMM. The CloudSat coordinate and time position were then matched with TRMM coordinate and time position. All of the processes were programatically conducted in fortran programming language. The result shows a transition between East and West Pacific ocean for TMI data.

Cloud computing challenges, limitations and R&D solutions

CERN Document Server

Mahmood, Zaigham

2014-01-01

This important text/reference reviews the challenging issues that present barriers to greater implementation of the cloud computing paradigm, together with the latest research into developing potential solutions. Exploring the strengths and vulnerabilities of cloud provision and cloud environments, Cloud Computing: Challenges, Limitations and R&D Solutions provides case studies from a diverse selection of researchers and practitioners of international repute. The implications of emerging cloud technologies are also analyzed from the perspective of consumers. Topics and features: presents

THE MAGELLANIC MOPRA ASSESSMENT (MAGMA). I. THE MOLECULAR CLOUD POPULATION OF THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Wong, Tony; Chu, You-Hua; Gruendl, Robert A.; Looney, Leslie W.; Seale, Jonathan; Welty, Daniel E.; Hughes, Annie; Maddison, Sarah; Ott, Jürgen; Muller, Erik; Fukui, Yasuo; Kawamura, Akiko; Mizuno, Yoji; Pineda, Jorge L.; Bernard, Jean-Philippe; Paradis, Deborah; Henkel, Christian; Klein, Ulrich

2011-01-01

We present the properties of an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) mapped at 11 pc resolution in the CO(1-0) line. Targets were chosen based on a limiting CO flux and peak brightness as measured by the NANTEN survey. The observations were conducted with the ATNF Mopra Telescope as part of the Magellanic Mopra Assessment. We identify clouds as regions of connected CO emission and find that the distributions of cloud sizes, fluxes, and masses are sensitive to the choice of decomposition parameters. In all cases, however, the luminosity function of CO clouds is steeper than dN/dL∝L –2 , suggesting that a substantial fraction of mass is in low-mass clouds. A correlation between size and linewidth, while apparent for the largest emission structures, breaks down when those structures are decomposed into smaller structures. We argue that the correlation between virial mass and CO luminosity is the result of comparing two covariant quantities, with the correlation appearing tighter on larger scales where a size-linewidth relation holds. The virial parameter (the ratio of a cloud's kinetic to self-gravitational energy) shows a wide range of values and exhibits no clear trends with the CO luminosity or the likelihood of hosting young stellar object (YSO) candidates, casting further doubt on the assumption of virialization for molecular clouds in the LMC. Higher CO luminosity increases the likelihood of a cloud harboring a YSO candidate, and more luminous YSOs are more likely to be coincident with detectable CO emission, confirming the close link between giant molecular clouds and massive star formation.

Toward low-cloud-permitting cloud superparameterization with explicit boundary layer turbulence

Science.gov (United States)

Parishani, Hossein; Pritchard, Michael S.; Bretherton, Christopher S.; Wyant, Matthew C.; Khairoutdinov, Marat

2017-07-01

Systematic biases in the representation of boundary layer (BL) clouds are a leading source of uncertainty in climate projections. A variation on superparameterization (SP) called "ultraparameterization" (UP) is developed, in which the grid spacing of the cloud-resolving models (CRMs) is fine enough (250 × 20 m) to explicitly capture the BL turbulence, associated clouds, and entrainment in a global climate model capable of multiyear simulations. UP is implemented within the Community Atmosphere Model using 2° resolution (˜14,000 embedded CRMs) with one-moment microphysics. By using a small domain and mean-state acceleration, UP is computationally feasible today and promising for exascale computers. Short-duration global UP hindcasts are compared with SP and satellite observations of top-of-atmosphere radiation and cloud vertical structure. The most encouraging improvement is a deeper BL and more realistic vertical structure of subtropical stratocumulus (Sc) clouds, due to stronger vertical eddy motions that promote entrainment. Results from 90 day integrations show climatological errors that are competitive with SP, with a significant improvement in the diurnal cycle of offshore Sc liquid water. Ongoing concerns with the current UP implementation include a dim bias for near-coastal Sc that also occurs less prominently in SP and a bright bias over tropical continental deep convection zones. Nevertheless, UP makes global eddy-permitting simulation a feasible and interesting alternative to conventionally parameterized GCMs or SP-GCMs with turbulence parameterizations for studying BL cloud-climate and cloud-aerosol feedback.

Remote Sensing of Crystal Shapes in Ice Clouds

Science.gov (United States)

van Diedenhoven, Bastiaan

2017-01-01

Ice crystals in clouds exist in a virtually limitless variation of geometries. The most basic shapes of ice crystals are columnar or plate-like hexagonal prisms with aspect ratios determined by relative humidity and temperature. However, crystals in ice clouds generally display more complex structures owing to aggregation, riming and growth histories through varying temperature and humidity regimes. Crystal shape is relevant for cloud evolution as it affects microphysical properties such as fall speeds and aggregation efficiency. Furthermore, the scattering properties of ice crystals are affected by their general shape, as well as by microscopic features such as surface roughness, impurities and internal structure. To improve the representation of ice clouds in climate models, increased understanding of the global variation of crystal shape and how it relates to, e.g., location, cloud temperature and atmospheric state is crucial. Here, the remote sensing of ice crystal macroscale and microscale structure from airborne and space-based lidar depolarization observations and multi-directional measurements of total and polarized reflectances is reviewed. In addition, a brief overview is given of in situ and laboratory observations of ice crystal shape as well as the optical properties of ice crystals that serve as foundations for the remote sensing approaches. Lidar depolarization is generally found to increase with increasing cloud height and to vary with latitude. Although this variation is generally linked to the variation of ice crystal shape, the interpretation of the depolarization remains largely qualitative and more research is needed before quantitative conclusions about ice shape can be deduced. The angular variation of total and polarized reflectances of ice clouds has been analyzed by numerous studies in order to infer information about ice crystal shapes from them. From these studies it is apparent that pristine crystals with smooth surfaces are generally

Cloud microphysical characteristics versus temperature for three Canadian field projects

Directory of Open Access Journals (Sweden)

I. Gultepe

2002-11-01

Full Text Available The purpose of this study is to better understand how cloud microphysical characteristics such as liquid water content (LWC and droplet number concentration (Nd change with temperature (T. The in situ observations were collected during three research projects including: the Radiation, Aerosol, and Cloud Experiment (RACE which took place over the Bay of Fundy and Central Ontario during August 1995, the First International Regional Arctic Cloud Experiment (FIRE.ACE which took place in the Arctic Ocean during April 1998, and the Alliance Icing Research Study (AIRS which took place in the Ontario region during the winter of 1999–2000. The RACE, FIRE.ACE, and AIRS projects represent summer mid-latitude clouds, Arctic clouds, and mid-latitude winter clouds, respectively. A LWC threshold of 0.005 g m-3 was used for this study. Similar to other studies, LWC was observed to decrease with decreasing T. The LWC-T relationship was similar for all projects, although the range of T conditions for each project was substantially different, and the variability of LWC within each project was considerable. Nd also decreased with decreasing T, and a parameterization for Nd versus T is suggested that may be useful for modeling studies.Key words. Atmospheric composition and structure (cloud physics and chemistry – Meteorology and atmospheric dynamics (climatology; general circulation

GIANT MOLECULAR CLOUD FORMATION IN DISK GALAXIES: CHARACTERIZING SIMULATED VERSUS OBSERVED CLOUD CATALOGS

Energy Technology Data Exchange (ETDEWEB)

Benincasa, Samantha M.; Pudritz, Ralph E.; Wadsley, James [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Tasker, Elizabeth J. [Department of Physics, Faculty of Science, Hokkaido University, Kita-ku, Sapporo 060-0810 (Japan)

2013-10-10

We present the results of a study of simulated giant molecular clouds (GMCs) formed in a Milky Way-type galactic disk with a flat rotation curve. This simulation, which does not include star formation or feedback, produces clouds with masses ranging between 10{sup 4} M{sub ☉} and 10{sup 7} M{sub ☉}. We compare our simulated cloud population to two observational surveys: the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey and the BIMA All-Disk Survey of M33. An analysis of the global cloud properties as well as a comparison of Larson's scaling relations is carried out. We find that simulated cloud properties agree well with the observed cloud properties, with the closest agreement occurring between the clouds at comparable resolution in M33. Our clouds are highly filamentary—a property that derives both from their formation due to gravitational instability in the sheared galactic environment, as well as to cloud-cloud gravitational encounters. We also find that the rate at which potentially star-forming gas accumulates within dense regions—wherein n{sub thresh} ≥ 10{sup 4} cm{sup –3}—is 3% per 10 Myr, in clouds of roughly 10{sup 6} M{sub ☉}. This suggests that star formation rates in observed clouds are related to the rates at which gas can be accumulated into dense subregions within GMCs via filamentary flows. The most internally well-resolved clouds are chosen for listing in a catalog of simulated GMCs—the first of its kind. The cataloged clouds are available as an extracted data set from the global simulation.

Cloud2IR: Infrared thermography and environmental sensors integrated in an autonomoussystem for long term monitoring of structures

Science.gov (United States)

Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barroso, Guillermo

2016-04-01

acquisition scenario the local storage management and the network management through SFTP or SOAP for the OGC frame. The data side only need an XML configuration file and if a configuration change occurs in time the system is automatically restarted with the new value. Cloud2IR has been deployed on field since several Monthat the SenseCity outdoor test bed in Marne La Vallée (France)[4]. The next step will be the full standardisation of the system and possibly the full separation between the sensor side and the data side which can be seen at term as an external framework. References: [1] A Crinière, J Dumoulin, L Mevel, G Andrade-Barosso, M Simonin. The Cloud2SM Project.European Geosciences Union General Assembly (EGU2015), Apr 2015, Vienne, Austria. 2015. [2] J Dumoulin, A Criniere, and R Averty. The detection and thermal characterization of the inner structure of the 'musmeci' bridge deck by infrared thermography monitoring. Journal Of Geophysics And Engineering doi:10.1088/1742-2132/10/6/064003, Vol 10, 2013. [3] J Dumoulin, R Averty. Development of an infrared system coupled with a weather station for real time atmospheric corrections using GPU computing: Application to bridge monitoring, in Proc of 11 th International Conference on Quantitative InfraRed Thermography, Naples Italy, 2012. [4] F Derkx, B Lebental, T Bourouina, Frédéric B, C Cojocaru, and al..The Sense-City project.XVIIIth Symposium on Vibrations, Shocks and Noise, Jul 2012, France. 9p, 2012.

Measurement errors in cirrus cloud microphysical properties

Directory of Open Access Journals (Sweden)

H. Larsen

Full Text Available The limited accuracy of current cloud microphysics sensors used in cirrus cloud studies imposes limitations on the use of the data to examine the cloud's broadband radiative behaviour, an important element of the global energy balance. We review the limitations of the instruments, PMS probes, most widely used for measuring the microphysical structure of cirrus clouds and show the effect of these limitations on descriptions of the cloud radiative properties. The analysis is applied to measurements made as part of the European Cloud and Radiation Experiment (EUCREX to determine mid-latitude cirrus microphysical and radiative properties.

Key words. Atmospheric composition and structure (cloud physics and chemistry · Meteorology and atmospheric dynamics · Radiative processes · Instruments and techniques

Factors influencing the organizational adoption of cloud computing: a survey among cloud workers

Directory of Open Access Journals (Sweden)

Mark Stieninger

2018-01-01

Full Text Available Cloud computing presents an opportunity for organizations to leverage affordable, scalable, and agile technologies. However, even with the demonstrated value of cloud computing, organizations have been hesitant to adopt such technologies. Based on a multi-theoretical research model, this paper provides an empirical study targeted to better understand the adoption of cloud services. An online survey addressing the factors derived from literature for three specific popular cloud application types (cloud storage, cloud mail and cloud office was undertaken. The research model was analyzed by using variance-based structural equation modelling. Results show that the factors of compatibility, relative advantage, security and trust, as well as, a lower level of complexity lead to a more positive attitude towards cloud adoption. Complexity, compatibility, image and security and trust have direct and indirect effects on relative advantage. These factors further explain a large part of the attitude towards cloud adoption but not of its usage.

Security and Privacy Implications of Cloud Computing – Lost in the Cloud

OpenAIRE

Tchifilionova , Vassilka

2010-01-01

Part 4: Security for Clouds; International audience; Cloud computing - the new paradigm, the future for IT consumer utility, the economy of scale approach, the illusion of un infinite resources availability, yet the debate over security and privacy issues is still undergoing and a common policy framework is missing. Research confirms that users are concern when presented with scenarios in which companies may put their data to uses of which they may not be aware. Therefore, privacy and securit...

2nd International Workshop on Learning Technology for Education in Cloud

CERN Document Server

Tao, Yu-Hui; Yang, Hsin-Chang; Ting, I-Hsien

2014-01-01

Proceedings from the 2013 LTEC conference in Kaohsiung,Taiwan. The papers examine diverse aspects of Learning Technology for Education in Cloud environments, including social, technical and infrastructure implications. Also addressed is the question of how cloud computing can be used to design applications to support real time on demand learning using technologies. The workshop proceedings provide opportunities for delegates to discuss the latest research in TEL (Technology Enhanced Learning) and its impacts for learners and institutions, using cloud technolgies.

Intercomparison of Vertical Structure of Storms Revealed by Ground-Based (NMQ and Spaceborne Radars (CloudSat-CPR and TRMM-PR

Directory of Open Access Journals (Sweden)

Veronica M. Fall

2013-01-01

Full Text Available Spaceborne radars provide great opportunities to investigate the vertical structure of clouds and precipitation. Two typical spaceborne radars for such a study are the W-band Cloud Profiling Radar (CPR and Ku-band Precipitation Radar (PR, which are onboard NASA’s CloudSat and TRMM satellites, respectively. Compared to S-band ground-based radars, they have distinct scattering characteristics for different hydrometeors in clouds and precipitation. The combination of spaceborne and ground-based radar observations can help in the identification of hydrometeors and improve the radar-based quantitative precipitation estimation (QPE. This study analyzes the vertical structure of the 18 January, 2009 storm using data from the CloudSat CPR, TRMM PR, and a NEXRAD-based National Mosaic and Multisensor QPE (NMQ system. Microphysics above, within, and below the melting layer are studied through an intercomparison of multifrequency measurements. Hydrometeors’ type and their radar scattering characteristics are analyzed. Additionally, the study of the vertical profile of reflectivity (VPR reveals the brightband properties in the cold-season precipitation and its effect on the radar-based QPE. In all, the joint analysis of spaceborne and ground-based radar data increases the understanding of the vertical structure of storm systems and provides a good insight into the microphysical modeling for weather forecasts.

Secure Cloud Computing Implementation Study For Singapore Military Operations

Science.gov (United States)

2016-09-01

50 Figure 7. Basic Military Cloud Features Integrated into the OODA Loop Figure 8. Process...demand via the network” to cloud users [2]. International Business Machines (IBM) defines it as “the delivery of on-demand computing resources...to Statista [6], the public cloud computing market has shown continuous revenue growth in cloud services, beginning with a notable increase in 5

Cloud-particle galactic gas dynamics and star formation

International Nuclear Information System (INIS)

Roberts, W.W. Jr.

1983-01-01

Galactic gas dynamics, spiral structure, and star formation are discussed in the context of N-body computational studies based on a cloud-particle model of the interstellar medium. On the small scale, the interstellar medium appears to be cloud-dominated and supernova-perturbed. The cloud-particle model simulates cloud-cloud collisions, the formation of stellar associations, and supernova explosions as dominant local processes. On the large scale in response to a spiral galactic gravitational field, global density waves and galactic shocks develop with large-scale characteristics similar to those found in continuum gas dynamical studies. Both the system of gas clouds and the system of young stellar associations forming from the clouds share in the global spiral structure. However, with the attributes of neither assuming a continuum of gas (as in continuum gas dynamical studies) nor requiring a prescribed equation of state such as the isothermal condition so often employed, the cloud-particle picture retains much of the detail lost in earlier work: namely, the small-scale features and structures so important in understanding the local, turbulent state of the interstellar medium as well as the degree of raggedness often observed superposed on global spiral structure. (Auth.)

Cloud Detours: A Non-intrusive Approach for Automatic Software Adaptation to the Cloud

OpenAIRE

Maia , Paulo; Vasconcelos , Michel; Mendonça , Nabor ,

2015-01-01

Part 1: Research Track; International audience; A major challenge facing cloud migration is the need to change a legacy (on-premise) application’s source code so that it can better benefit from the inherit cloud computing characteristics, such as resource elasticity and high scalability. When performed manually, those changes are error-prone and may require a great effort from application developers. This paper presents a novel approach to support organizations in automatically adapting their...

Simulating the evolution of optically dark HI clouds in the Virgo cluster : will no-one rid me of this turbulent sphere ?

Science.gov (United States)

Taylor, R.; Wünsch, R.; Palouš, J.

2018-05-01

Most detected neutral atomic hydrogen (HI) at low redshift is associated with optically bright galaxies. However, a handful of HI clouds are known which appear to be optically dark and have no nearby potential progenitor galaxies, making tidal debris an unlikely explanation. In particular, 6 clouds identified by the Arecibo Galaxy Environment Survey are interesting due to the combination of their small size, isolation, and especially their broad line widths atypical of other such clouds. A recent suggestion is that these clouds exist in pressure equilibrium with the intracluster medium, with the line width arising from turbulent internal motions. Here we explore that possibility by using the FLASH code to perform a series of 3D hydro simulations. Our clouds are modelled using spherical Gaussian density profiles, embedded in a hot, low-density gas representing the intracluster medium. The simulations account for heating and cooling of the gas, and we vary the structure and strength of their internal motions. We create synthetic HI spectra, and find that none of our simulations reproduce the observed cloud parameters for longer than ˜100 Myr : the clouds either collapse, disperse, or experience rapid heating which would cause ionisation and render them undetectable to HI surveys. While the turbulent motions required to explain the high line widths generate structures which appear to be inherently unstable, making this an unlikely explanation for the observed clouds, these simulations demonstrate the importance of including the intracluster medium in any model seeking to explain the existence of these objects.

Cloud Computing Governance Lifecycle

OpenAIRE

Soňa Karkošková; George Feuerlicht

2016-01-01

Externally provisioned cloud services enable flexible and on-demand sourcing of IT resources. Cloud computing introduces new challenges such as need of business process redefinition, establishment of specialized governance and management, organizational structures and relationships with external providers and managing new types of risk arising from dependency on external providers. There is a general consensus that cloud computing in addition to challenges brings many benefits but it is uncle...

The morphological evolution and internal convection of ExB-drifting plasma clouds: Theory, dielectric-in-cell simulations, and N-body dielectric simulations

International Nuclear Information System (INIS)

Borovsky, J.E.; Hansen, P.J.

1998-01-01

The evolution of ExB-drifting plasma clouds is investigated with the aid of a computational technique denoted here as open-quotes dielectric-in-cell.close quotes Many of the familiar phenomena associated with clouds of collisionless plasma are seen and explained and less-well-known phenomena associated with convection patterns, with the stripping of cloud material, and with the evolution of plasma clouds composed of differing ion species are investigated. The effects of spatially uniform diffusion are studied with the dielectric-in-cell technique and with another computational technique denoted as open-quotes N-body dielectric;close quotes the suppression of convection, the suppression of structure growth, the increase in material stripping, and the evolution of cloud anisotropy are examined. copyright 1998 American Institute of Physics

Ultimate internal pressure capacity assessment of SC structure

International Nuclear Information System (INIS)

Park, Hyungkui; Choi, Inkil

2013-01-01

An SC structure applied to a containment building can be quite effective. However, an SC structure cannot be applied to a containment building, because its internal pressure resistance performance has not been verified. The containment building, which undergoes ultimate internal pressure, resists the internal pressure through a pre-stress tendon. It is hard to apply a tendon to an SC structure because of its structural characteristics. Therefore, the internal pressure resistance performance of the SC structure itself should be ensured to apply it to a structure with internal pressure resistance. In this study, the suitability of an SC structure as a substitution for the tendon of a pressure resistant structure was evaluated. A containment structure model was used in this study, because it was representative structures that resistance of ultimate internal pressure be required. In this study, a nonlinear analysis was performed to evaluate and compare the behaviors of tendon model and SC structure model. By comparing the internal pressure-displacement according to the structure type, the stability of SC structure model was assessed

Trust: A Requirement for Cloud Technology Adoption

OpenAIRE

Akinwale O. Akinwunmi; Emmanuel A. Olajubu; G. Adesola Aderounmu

2015-01-01

Cloud computing is a recent model for enabling convenient, on-demand network access to a shared pool of configurable computing resources such as networks, servers, storage, applications, and services; that can be rapidly provisioned and released with minimal management effort or service provider interaction. Studies have shown that cloud computing has the potential to benefit establishments, industries, national and international economies. Despite the enormous benefits cloud computing techno...

Moving to the cloud corporation how to face the challenges and harness the potential of cloud computing

CERN Document Server

Willcocks, Leslie; Whitley, Edgar A

2013-01-01

Drawing on an international survey of over 1,000 business and executives, this book provides a management perspective on cloud technology. It outlines the need to know information for strategic decisions on cloud technology including its capabilities, how it can be implemented securely and the way forward for the next ten years.

Star clouds of Magellan

International Nuclear Information System (INIS)

Tucker, W.

1981-01-01

The Magellanic Clouds are two irregular galaxies belonging to the local group which the Milky Way belongs to. By studying the Clouds, astronomers hope to gain insight into the origin and composition of the Milky Way. The overall structure and dynamics of the Clouds are clearest when studied in radio region of the spectrum. One benefit of directly observing stellar luminosities in the Clouds has been the discovery of the period-luminosity relation. Also, the Clouds are a splendid laboratory for studying stellar evolution. It is believed that both Clouds may be in the very early stage in the development of a regular, symmetric galaxy. This raises a paradox because some of the stars in the star clusters of the Clouds are as old as the oldest stars in our galaxy. An explanation for this is given. The low velocity of the Clouds with respect to the center of the Milky Way shows they must be bound to it by gravity. Theories are given on how the Magellanic Clouds became associated with the galaxy. According to current ideas the Clouds orbits will decay and they will spiral into the Galaxy

AUTOMATED VOXEL MODEL FROM POINT CLOUDS FOR STRUCTURAL ANALYSIS OF CULTURAL HERITAGE

Directory of Open Access Journals (Sweden)

G. Bitelli

2016-06-01

Full Text Available In the context of cultural heritage, an accurate and comprehensive digital survey of a historical building is today essential in order to measure its geometry in detail for documentation or restoration purposes, for supporting special studies regarding materials and constructive characteristics, and finally for structural analysis. Some proven geomatic techniques, such as photogrammetry and terrestrial laser scanning, are increasingly used to survey buildings with different complexity and dimensions; one typical product is in form of point clouds. We developed a semi-automatic procedure to convert point clouds, acquired from laserscan or digital photogrammetry, to a filled volume model of the whole structure. The filled volume model, in a voxel format, can be useful for further analysis and also for the generation of a Finite Element Model (FEM of the surveyed building. In this paper a new approach is presented with the aim to decrease operator intervention in the workflow and obtain a better description of the structure. In order to achieve this result a voxel model with variable resolution is produced. Different parameters are compared and different steps of the procedure are tested and validated in the case study of the North tower of the San Felice sul Panaro Fortress, a monumental historical building located in San Felice sul Panaro (Modena, Italy that was hit by an earthquake in 2012.

Surveying the Dense Gas in Barnard 1 and NGC 1333 from Cloud to Core Scales

Science.gov (United States)

Storm, Shaye; Mundy, Lee; Teuben, Peter; Lee, Katherine; Fernandez-Lopez, Manuel; Looney, Leslie; Rosolowsky, Erik; Classy Collaboration

2013-07-01

The CARMA Large Area Star formation Survey (CLASSy) is mapping molecular emission across large areas of the nearby Perseus and Serpens Molecular Clouds. With an angular resolution of 7 arcsec, CLASSy probes dense gas on scales from a few thousand AU to parsecs with CARMA-23 and single-dish observations. The resulting maps of N2H+, HCN, and HCO+ J=1-0 trace the kinematics and structure of the high-density gas in regions covering a wide range of intrinsic star formation activity. This poster presents an overview of three completed CLASSy fields, NGC 1333, Barnard 1, and Serpens Main, and then focuses on the dendrogram analysis that CLASSy is using to characterize the emission structure. We have chosen a dendrogram analysis over traditional clump finding because dendrograms better encode the hierarchical nature of cloud structure and better facilitate analysis of cloud properties across the range of size scales probed by CLASSy. We present a new dendrogram methodology that allows for non-binary mergers of kernels, which results in a gas hierarchy that is more true to limitations of the S/N in the data. The resulting trees from Barnard 1 and NGC 1333 are used to derive physical parameters of the identified gas structures, and to probe the kinematic relationship between gas structures at different spatial scales and evolutionary stages. We derive a flat relation between mean internal turbulence and structure size for the dense gas in both regions, but find a difference between the magnitude of the internal turbulence in regions with and without protostars; the dense gas in the B1 main core and NGC 1333 are characterized by mostly transonic to supersonic turbulence, while the B1 filaments and clumps southwest of the main core have mostly subsonic turbulence. These initial results, along with upcoming work analyzing the completed CLASSy observations, will be used to test current theories for star formation in turbulent molecular clouds.

Rozšíření SOA do platformy cloud computing

OpenAIRE

Qylafku, Denis

2010-01-01

The aim of my diploma thesis is to introduce cloud computing as an alternative to traditional internal information technology and its benefits for a company. Diploma thesis focuses on three main goals. The first one concerns advantages and disadvantages of cloud computing in comparison to internal information technology. The second one is identification of possible processes and services available for migration into cloud computing. The third goal of the diploma thesis is development of inves...

Software engineering frameworks for the cloud computing paradigm

CERN Document Server

Mahmood, Zaigham

2013-01-01

This book presents the latest research on Software Engineering Frameworks for the Cloud Computing Paradigm, drawn from an international selection of researchers and practitioners. The book offers both a discussion of relevant software engineering approaches and practical guidance on enterprise-wide software deployment in the cloud environment, together with real-world case studies. Features: presents the state of the art in software engineering approaches for developing cloud-suitable applications; discusses the impact of the cloud computing paradigm on software engineering; offers guidance an

Cloud-Based Evaluation of Anatomical Structure Segmentation and Landmark Detection Algorithms : VISCERAL Anatomy Benchmarks

OpenAIRE

Jimenez-del-Toro, Oscar; Muller, Henning; Krenn, Markus; Gruenberg, Katharina; Taha, Abdel Aziz; Winterstein, Marianne; Eggel, Ivan; Foncubierta-Rodriguez, Antonio; Goksel, Orcun; Jakab, Andres; Kontokotsios, Georgios; Langs, Georg; Menze, Bjoern H.; Fernandez, Tomas Salas; Schaer, Roger

2016-01-01

Variations in the shape and appearance of anatomical structures in medical images are often relevant radiological signs of disease. Automatic tools can help automate parts of this manual process. A cloud-based evaluation framework is presented in this paper including results of benchmarking current state-of-the-art medical imaging algorithms for anatomical structure segmentation and landmark detection: the VISCERAL Anatomy benchmarks. The algorithms are implemented in virtual machines in the ...

Coherent Radiation of Electron Cloud

International Nuclear Information System (INIS)

Heifets, S.

2004-01-01

The electron cloud in positron storage rings is pinched when a bunch passes by. For short bunches, the radiation due to acceleration of electrons of the cloud is coherent. Detection of such radiation can be used to measure the density of the cloud. The estimate of the power and the time structure of the radiated signal is given in this paper

Ice crystallization in ultrafine water-salt aerosols: nucleation, ice-solution equilibrium, and internal structure.

Science.gov (United States)

Hudait, Arpa; Molinero, Valeria

2014-06-04

solution. We predict that micrometer-sized particles and nanoparticles have the same equilibrium internal structure. The variation of liquid-vapor surface tension with solute concentration is a key factor in determining whether a solution-embedded ice core or vapor-exposed ice cap is the equilibrium structure of the aerosols. In agreement with experiments, we predict that the structure of mixed-phase HNO3-water particles, representative of polar stratospheric clouds, consists of an ice core surrounded by freeze-concentrated solution. The results of this work are important to determine the phase state and internal structure of sea spray ultrafine aerosols and other mixed-phase particles under atmospherically relevant conditions.

Do Clouds Compute? A Framework for Estimating the Value of Cloud Computing

Science.gov (United States)

Klems, Markus; Nimis, Jens; Tai, Stefan

On-demand provisioning of scalable and reliable compute services, along with a cost model that charges consumers based on actual service usage, has been an objective in distributed computing research and industry for a while. Cloud Computing promises to deliver on this objective: consumers are able to rent infrastructure in the Cloud as needed, deploy applications and store data, and access them via Web protocols on a pay-per-use basis. The acceptance of Cloud Computing, however, depends on the ability for Cloud Computing providers and consumers to implement a model for business value co-creation. Therefore, a systematic approach to measure costs and benefits of Cloud Computing is needed. In this paper, we discuss the need for valuation of Cloud Computing, identify key components, and structure these components in a framework. The framework assists decision makers in estimating Cloud Computing costs and to compare these costs to conventional IT solutions. We demonstrate by means of representative use cases how our framework can be applied to real world scenarios.

THE MASS-SIZE RELATION FROM CLOUDS TO CORES. I. A NEW PROBE OF STRUCTURE IN MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Kauffmann, J.; Shetty, R.; Goodman, A. A.; Pillai, T.; Myers, P. C.

2010-01-01

We use a new contour-based map analysis technique to measure the mass and size of molecular cloud fragments continuously over a wide range of spatial scales (0.05 ≤ r/pc ≤ 10), i.e., from the scale of dense cores to those of entire clouds. The present paper presents the method via a detailed exploration of the Perseus molecular cloud. Dust extinction and emission data are combined to yield reliable scale-dependent measurements of mass. This scale-independent analysis approach is useful for several reasons. First, it provides a more comprehensive characterization of a map (i.e., not biased toward a particular spatial scale). Such a lack of bias is extremely useful for the joint analysis of many data sets taken with different spatial resolution. This includes comparisons between different cloud complexes. Second, the multi-scale mass-size data constitute a unique resource to derive slopes of mass-size laws (via power-law fits). Such slopes provide singular constraints on large-scale density gradients in clouds.

The Musca cloud: A 6 pc-long velocity-coherent, sonic filament

Science.gov (United States)

Hacar, A.; Kainulainen, J.; Tafalla, M.; Beuther, H.; Alves, J.

2016-03-01

Filaments play a central role in the molecular clouds' evolution, but their internal dynamical properties remain poorly characterized. To further explore the physical state of these structures, we have investigated the kinematic properties of the Musca cloud. We have sampled the main axis of this filamentary cloud in 13CO and C18O (2-1) lines using APEX observations. The different line profiles in Musca shows that this cloud presents a continuous and quiescent velocity field along its ~6.5 pc of length. With an internal gas kinematics dominated by thermal motions (I.e. σNT/cs ≲ 1) and large-scale velocity gradients, these results reveal Musca as the longest velocity-coherent, sonic-like object identified so far in the interstellar medium. The transonic properties of Musca present a clear departure from the predicted supersonic velocity dispersions expected in the Larson's velocity dispersion-size relationship, and constitute the first observational evidence of a filament fully decoupled from the turbulent regime over multi-parsec scales. This publication is based on data acquired with the Atacama Pathfinder Experiment (APEX). APEX is a collaboration between the Max-Planck-Institut fuer Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory (ESO programme 087.C-0583).The reduced datacubes as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A97

Assessment of global cloud datasets from satellites: Project and database initiated by the GEWEX radiation panel

OpenAIRE

Stubenrauch , C.J.; Rossow , W.B.; Kinne , S.; Ackerman , S.; Cesana , G.; Chepfer , H.; Di Girolamo , L.; Getzewich , B.; Guignard , A.; Heidinger , A.; Maddux , B.C.; Menzel , W.P.; Minnis , P.; Pearl , C.; Platnick , S.

2013-01-01

International audience; The Global Energy and Water Cycle Experiment (GEWEX) Radiation Panel initiated the GEWEX Cloud Assessment in 2005 to compare available, global, long-term cloud data products with the International Satellite Cloud Climatology Project (ISCCP). The GEWEX Cloud Assessment database included cloud properties retrieved from different satellite sensor measurements, taken at various local times and over various time periods. The relevant passive satellite sensors measured radia...

Privacy and legal issues in cloud computing

CERN Document Server

Weber, Rolf H

2015-01-01

Adopting a multi-disciplinary and comparative approach, this book focuses on emerging and innovative attempts to tackle privacy and legal issues in cloud computing, such as personal data privacy, security and intellectual property protection. Leading international academics and practitioners in the fields of law and computer science examine the specific legal implications of cloud computing pertaining to jurisdiction, biomedical practice and information ownership. This collection offers original and critical responses to the rising challenges posed by cloud computing.

Software Product Lines for Multi-Cloud Microservices-Based Applications

OpenAIRE

Sousa , Gustavo; Rudametkin , Walter; Duchien , Laurence

2016-01-01

International audience; Multi-cloud computing is the use of resources and services from multiple independent cloud providers. It is used to avoid vendor lock-in, comply with location regulations, and optimize reliability, performance and costs. Microservices is an architectural style becoming increasingly used in cloud computing as it allows for better resources usage. However, building multi-cloud systems is a very complex and time consuming task, which calls for automation and supporting to...

Trusted computing strengthens cloud authentication.

Science.gov (United States)

Ghazizadeh, Eghbal; Zamani, Mazdak; Ab Manan, Jamalul-lail; Alizadeh, Mojtaba

2014-01-01

Cloud computing is a new generation of technology which is designed to provide the commercial necessities, solve the IT management issues, and run the appropriate applications. Another entry on the list of cloud functions which has been handled internally is Identity Access Management (IAM). Companies encounter IAM as security challenges while adopting more technologies became apparent. Trust Multi-tenancy and trusted computing based on a Trusted Platform Module (TPM) are great technologies for solving the trust and security concerns in the cloud identity environment. Single sign-on (SSO) and OpenID have been released to solve security and privacy problems for cloud identity. This paper proposes the use of trusted computing, Federated Identity Management, and OpenID Web SSO to solve identity theft in the cloud. Besides, this proposed model has been simulated in .Net environment. Security analyzing, simulation, and BLP confidential model are three ways to evaluate and analyze our proposed model.

Trusted Computing Strengthens Cloud Authentication

Directory of Open Access Journals (Sweden)

Eghbal Ghazizadeh

2014-01-01

Full Text Available Cloud computing is a new generation of technology which is designed to provide the commercial necessities, solve the IT management issues, and run the appropriate applications. Another entry on the list of cloud functions which has been handled internally is Identity Access Management (IAM. Companies encounter IAM as security challenges while adopting more technologies became apparent. Trust Multi-tenancy and trusted computing based on a Trusted Platform Module (TPM are great technologies for solving the trust and security concerns in the cloud identity environment. Single sign-on (SSO and OpenID have been released to solve security and privacy problems for cloud identity. This paper proposes the use of trusted computing, Federated Identity Management, and OpenID Web SSO to solve identity theft in the cloud. Besides, this proposed model has been simulated in .Net environment. Security analyzing, simulation, and BLP confidential model are three ways to evaluate and analyze our proposed model.

Trusted Computing Strengthens Cloud Authentication

Science.gov (United States)

2014-01-01

Cloud computing is a new generation of technology which is designed to provide the commercial necessities, solve the IT management issues, and run the appropriate applications. Another entry on the list of cloud functions which has been handled internally is Identity Access Management (IAM). Companies encounter IAM as security challenges while adopting more technologies became apparent. Trust Multi-tenancy and trusted computing based on a Trusted Platform Module (TPM) are great technologies for solving the trust and security concerns in the cloud identity environment. Single sign-on (SSO) and OpenID have been released to solve security and privacy problems for cloud identity. This paper proposes the use of trusted computing, Federated Identity Management, and OpenID Web SSO to solve identity theft in the cloud. Besides, this proposed model has been simulated in .Net environment. Security analyzing, simulation, and BLP confidential model are three ways to evaluate and analyze our proposed model. PMID:24701149

SUNYA Regional Climate Model Simulations of East Asia Summer Monsoon: Effects of Cloud Vertical Structure on the Surface Energy Balance

Directory of Open Access Journals (Sweden)

Wei Gong and Wei-Chyung Wang

2007-01-01

-seasonal variation of shortwave CRF, indicating the importance of cloud vertical structure. The strong negative feedbacks from the responses of latent and sensible heat flux tend to limit the effects of low clouds on the surface temperature simulations, as evidently the surface air temperatures bias of only _ in the EASM simulations while the variances of the surface radiative fluxes and heat fluxes are, respectively, in the ranges of 100 - 200 and 60 - 110 Wm-2 when total cloud cover are all near 80%. Therefore, it is also concluded that surface air temperature, precipitation, and total cloud cover, which are three frequently examined variables for climate models, are not sufficient for model evaluation, but instead the cloud vertical structure needs to be examined.

Molecular clouds near supernova remnants

International Nuclear Information System (INIS)

Wootten, H.A.

1978-01-01

The physical properties of molecular clouds near supernova remnants were investigated. Various properties of the structure and kinematics of these clouds are used to establish their physical association with well-known remmnants. An infrared survey of the most massive clouds revealed embedded objects, probably stars whose formation was induced by the supernova blast wave. In order to understand the relationship between these and other molecular clouds, a control group of clouds was also observed. Excitation models for dense regions of all the clouds are constructed to evaluate molecular abundances in these regions. Those clouds that have embedded stars have lower molecular abundances than the clouds that do not. A cloud near the W28 supernova remnant also has low abundances. Molecular abundances are used to measure an important parameter, the electron density, which is not directly observable. In some clouds extensive deuterium fractionation is observed which confirms electron density measurements in those clouds. Where large deuterium fractionation is observed, the ionization rate in the cloud interior can also be measured. The electron density and ionization rate in the cloud near W28 are higher than in most clouds. The molecular abundances and electron densities are functions of the chemical and dynamical state of evolution of the cloud. Those clouds with lowest abundances are probably the youngest clouds. As low-abundance clouds, some clouds near supernova remnants may have been recently swept from the local interstellar material. Supernova remnants provide sites for star formation in ambient clouds by compressing them, and they sweep new clouds from more diffuse local matter

Structured Cloud Federation for Carrier and ISP Infrastructure

OpenAIRE

Xhagjika, Vamis; Vlassov, Vladimir; Molin, Magnus; Toma, Simona

2014-01-01

Cloud Computing in recent years has seen enhanced growth and extensive support by the research community and industry. The advent of cloud computing realized the concept of commodity computing, in which infrastructure (resources) can be allocated on demand giving the illusion of infinite resource availability. The state-of-art Carrier and ISP infrastructure technology is composed of tightly coupled software services with the underlying customized hardware architecture. The fast growth of clou...

The Impact Of Cloud Computing Technology On The Audit Process And The Audit Profession

Directory of Open Access Journals (Sweden)

Yati Nurhajati

2015-08-01

Full Text Available In the future cloud computing audits will become increasingly The use of that technology has influenced of the audit process and be a new challenge for both external and the Internal Auditors to understand IT and learn how to use cloud computing and cloud services that hire in cloud service provider CSP and considering the risks of cloud computing and how to audit cloud computing by risk based audit approach. The wide range of unique risks and depend on the type and model of the cloud solution the uniqueness of the client environmentand the specifics of data or an application make this an complicated subject. The internal audit function is well positioned through its role as a guarantor function of the organization to assist management and the board of the Committee to identify and consider the risks in using cloud computing technology for internal audit can help determine whether the risk has been managed appropriately in a cloud computing environment. Assesses the current impact of cloud computing technology on the audit process and discusses the implications of cloud computing future technological trends for the auditing profession . More specifically Provides a summary of how that information technology has impacted the audit framework.

Marine Cloud Brightening

Energy Technology Data Exchange (ETDEWEB)

Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

2012-09-07

The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

Marine cloud brightening.

Science.gov (United States)

Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

2012-09-13

The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could-subject to satisfactory resolution of technical and scientific problems identified herein-have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

High-Resolution Imaging of Dense Gas Structure and Kinematics in Nearby Molecular Clouds with the CARMA Large Area Star Formation Survey

Science.gov (United States)

Storm, Shaye

This thesis utilizes new observations of dense gas in molecular clouds to develop an empirical framework for how clouds form structures which evolve into young cores and stars. Previous observations show the general turbulent and hierarchical nature of clouds. However, current understanding of the star formation pathway is limited by existing data that do not combine angular resolution needed to resolve individual cores with area coverage required to capture entire star-forming regions and with tracers that can resolve gas motions. The original contributions of this thesis to astrophysical research are the creation and analysis of the largest-area high-angular-resolution maps of dense gas in molecular clouds to-date, and the development of a non-binary dendrogram algorithm to quantify the hierarchical nature and three-dimensional morphology of cloud structure. I first describe the CARMA Large Area Star Formation Survey, which provides spectrally imaged N2H+, HCO+, and HCN (J = 1→0) emission across diverse regions of the Perseus and Serpens Molecular Clouds. I then present a detailed analysis of the Barnard 1 and L1451 regions in Perseus. A non-binary dendrogram analysis of Barnard 1 N2H emission and all L1451 emission shows that the most hierarchically complex gas corresponds with sub-regions actively forming young stars. I estimate the typical depth of molecular emission in each region using the spatial and kinematic properties of dendrogram-identified structures. Barnard 1 appears to be a sheet-like region at the largest scales with filamentary substructure, while the L1451 region is composed of more spatially distinct ellipsoidal structures. I then do a uniform comparison of the hierarchical structure and young stellar content of all five regions. The more evolved regions with the most young stellar objects (YSOs) and strongest emission have formed the most hierarchical levels. However, all regions show similar mean branching properties at each level

Definition of "banner clouds" based on time lapse movies

OpenAIRE

Schween , J. H.; Kuettner , J.; Reinert , D.; Reuder , J.; Wirth , V.

2007-01-01

International audience; Banner clouds appear on the leeward side of a mountain and resemble a banner or a flag. This article provides a comprehensive definition of "banner clouds". It is based primarily on an extensive collection of time lapse movies, but previous attempts at an explanation of this phenomenon are also taken into account. The following ingredients are considered essential: the cloud must be attached to the mountain but not appear on the windward side; the cloud must originate ...

Electron-Cloud Build-Up: Summary

International Nuclear Information System (INIS)

Furman, M.A.

2007-01-01

I present a summary of topics relevant to the electron-cloud build-up and dissipation that were presented at the International Workshop on Electron-Cloud Effects 'ECLOUD 07' (Daegu, S. Korea, April 9-12, 2007). This summary is not meant to be a comprehensive review of the talks. Rather, I focus on those developments that I found, in my personal opinion, especially interesting. The contributions, all excellent, are posted in http://chep.knu.ac.kr/ecloud07/

Virial theorem analysis of the structure and stability of magnetized clouds

International Nuclear Information System (INIS)

Zweibel, E.G.

1990-01-01

The tensor virial theorem is used to analyze the structure and stability of self-gravitating, magnetized spheroids surrounded by a low-density medium with pressure and magnetic field. Analytical expressions are developed for the effect of a weak field and calculate critical states when the effect of the field is arbitrarily strong, comparing the results with full magnetohydrostatic calculations. This analysis suggests that a magnetic field may prevent gravitational collapse but may also be destabilizing, depending on its degree of concentration within the cloud. 34 refs

CloudNeo: a cloud pipeline for identifying patient-specific tumor neoantigens.

Science.gov (United States)

Bais, Preeti; Namburi, Sandeep; Gatti, Daniel M; Zhang, Xinyu; Chuang, Jeffrey H

2017-10-01

We present CloudNeo, a cloud-based computational workflow for identifying patient-specific tumor neoantigens from next generation sequencing data. Tumor-specific mutant peptides can be detected by the immune system through their interactions with the human leukocyte antigen complex, and neoantigen presence has recently been shown to correlate with anti T-cell immunity and efficacy of checkpoint inhibitor therapy. However computing capabilities to identify neoantigens from genomic sequencing data are a limiting factor for understanding their role. This challenge has grown as cancer datasets become increasingly abundant, making them cumbersome to store and analyze on local servers. Our cloud-based pipeline provides scalable computation capabilities for neoantigen identification while eliminating the need to invest in local infrastructure for data transfer, storage or compute. The pipeline is a Common Workflow Language (CWL) implementation of human leukocyte antigen (HLA) typing using Polysolver or HLAminer combined with custom scripts for mutant peptide identification and NetMHCpan for neoantigen prediction. We have demonstrated the efficacy of these pipelines on Amazon cloud instances through the Seven Bridges Genomics implementation of the NCI Cancer Genomics Cloud, which provides graphical interfaces for running and editing, infrastructure for workflow sharing and version tracking, and access to TCGA data. The CWL implementation is at: https://github.com/TheJacksonLaboratory/CloudNeo. For users who have obtained licenses for all internal software, integrated versions in CWL and on the Seven Bridges Cancer Genomics Cloud platform (https://cgc.sbgenomics.com/, recommended version) can be obtained by contacting the authors. jeff.chuang@jax.org. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

RACORO Extended-Term Aircraft Observations of Boundary-Layer Clouds

Science.gov (United States)

Vogelmann, Andrew M.; McFarquhar, Greg M.; Ogren, John A.; Turner, David D.; Comstock, Jennifer M.; Feingold, Graham; Long, Charles N.; Jonsson, Haflidi H.; Bucholtz, Anthony; Collins, Don R.;

Plane-parallel biases computed from inhomogeneous Arctic clouds and sea ice

Science.gov (United States)

Rozwadowska, Anna; Cahalan, Robert F.

2002-10-01

Monte Carlo simulations of the expected influence of nonuniformity in cloud structure and surface albedo on shortwave radiative fluxes in the Arctic atmosphere are presented. In particular, plane-parallel biases in cloud albedo and transmittance are studied for nonabsorbing, low-level, all-liquid stratus clouds over sea ice. The "absolute bias" is defined as the difference between the cloud albedo or transmittance for the uniform or plane-parallel case, and the albedo or transmittance for nonuniform conditions with the same mean cloud optical thickness and the same mean surface albedo, averaged over a given area (i.e., bias > 0 means plane-parallel overestimates). Ranges of means and standard deviations of input parameters typical of Arctic conditions are determined from the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment Artic Cloud Experiment (FIRE/ACE)/Surface Heat Budget of the Arctic Ocean (SHEBA)/Atmospheric Radiation Measurement Program (ARM) experiment, a cooperative effort of the Department of Energy, NASA, NSF, the National Oceanic and Atmospheric Administration, the Office of Naval Research, and the Atmospheric Environment Service. We determine the sensitivity of the bias with respect to the following: domain averaged means and spatial variances of cloud optical thickness and surface albedo, shape of the surface reflectance function, presence of a scattering layer under the clouds, and solar zenith angle. The simulations show that the biases in Arctic conditions are generally lower than in subtropical stratocumulus. The magnitudes of the absolute biases are unlikely to exceed 0.02 for albedo and 0.05 for transmittance. The "relative bias" expresses the absolute bias as a percentage of the actual cloud albedo or transmittance. The magnitude of the relative bias in albedo is typically below 2% over the reflective Arctic surface, while the magnitude of the relative bias in transmittance can exceed 10%.

Cloud chamber photographs of the cosmic radiation

CERN Document Server

Rochester, George Dixon

1952-01-01

Cloud Chamber Photographs of the Cosmic Radiation focuses on cloud chamber and photographic emulsion wherein the tracks of individual subatomic particles of high energy are studied. The publication first offers information on the technical features of operation and electrons and cascade showers. Discussions focus on the relationship in time and space of counter-controlled tracks; techniques of internal control of the cloud chamber; cascade processes with artificially-produced electrons and photons; and nuclear interaction associated with an extensive shower. The manuscript then elaborates on

HammerCloud: A Stress Testing System for Distributed Analysis

International Nuclear Information System (INIS)

Ster, Daniel C van der; García, Mario Úbeda; Paladin, Massimo; Elmsheuser, Johannes

2011-01-01

Distributed analysis of LHC data is an I/O-intensive activity which places large demands on the internal network, storage, and local disks at remote computing facilities. Commissioning and maintaining a site to provide an efficient distributed analysis service is therefore a challenge which can be aided by tools to help evaluate a variety of infrastructure designs and configurations. HammerCloud is one such tool; it is a stress testing service which is used by central operations teams, regional coordinators, and local site admins to (a) submit arbitrary number of analysis jobs to a number of sites, (b) maintain at a steady-state a predefined number of jobs running at the sites under test, (c) produce web-based reports summarizing the efficiency and performance of the sites under test, and (d) present a web-interface for historical test results to both evaluate progress and compare sites. HammerCloud was built around the distributed analysis framework Ganga, exploiting its API for grid job management. HammerCloud has been employed by the ATLAS experiment for continuous testing of many sites worldwide, and also during large scale computing challenges such as STEP'09 and UAT'09, where the scale of the tests exceeded 10,000 concurrently running and 1,000,000 total jobs over multi-day periods. In addition, HammerCloud is being adopted by the CMS experiment; the plugin structure of HammerCloud allows the execution of CMS jobs using their official tool (CRAB).

Effect of remote clouds on surface UV irradiance

Energy Technology Data Exchange (ETDEWEB)

Deguenther, M.; Meerkoetter, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

2000-06-01

Clouds affect local surface UV irradiance, even if the horizontal distance from the radiation observation site amounts to several kilometers. In order to investigate this effect, which we call remote clouds effect, a 3-dimensional radiative transfer model is applied. Assuming the atmosphere is subdivided into a quadratic based sector and its surrounding, we quantify the influence of changing cloud coverage within this surrounding from 0% to 100% on surface UV irradiance at the sector center. To work out this remote clouds influence as a function of sector base size, we made some calculations for different sizes between 10 km x 10 km and 100 km x 100 km. It appears that in the case of small sectors (base size {<=}20 km x 20 km) the remote clouds effect is highly variable: Depending on cloud structure, solar zenith angle and wavelength, the surface UV irradiance may be enhanced up to 15% as well as reduced by more than 50%. In contrast, for larger sectors it is always the case that enhancements become smaller by 5% if sector base size exceeds 60 km x 60 km. However, these values are upper estimates of the remote cloud effects and they are found only for special cloud structures. Since these structures might occur but cannot be regarded as typical, different satellite observed cloud formations (horizontal resolution about 1 km x 1 km) have also been investigated. For these more common cloud distributions we find remote cloud effects to be distinctly smaller than the corresponding upper estimates, e.g., for a sector with base size of 25 km x 25 km the surface UV irradiance error due to ignoring the actual remote clouds and replacing their influence with periodic horizontal boundary conditions is less than 3%, whereas the upper estimate of remote clouds effect would suggest an error close to 10%. (orig.)

Shock–Cloud Interaction in the Solar Corona

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Takuya, E-mail: takahashi@kwasan.kyoto-u.ac.jp [Department of Astronomy, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan)

2017-02-20

Flare-associated coronal shock waves sometimes interact with solar prominences, leading to large-amplitude prominence oscillations (LAPOs). Such prominence activation gives us a unique opportunity to track the time evolution of shock–cloud interaction in cosmic plasmas. Although the dynamics of interstellar shock–cloud interaction has been extensively studied, coronal shock–solar prominence interaction is rarely studied in the context of shock–cloud interaction. Associated with the X5.4 class solar flare that occurred on 2012 March 7, a globally propagated coronal shock wave interacted with a polar prominence, leading to LAPO. In this paper, we studied bulk acceleration and excitation of the internal flow of the shocked prominence using three-dimensional magnetohydrodynamic (MHD) simulations. We studied eight MHD simulation runs, each with different mass density structure of the prominence, and one hydrodynamic simulation run, and we compared the result. In order to compare the observed motion of activated prominence with the corresponding simulation, we also studied prominence activation by injection of a triangular-shaped coronal shock. We found that the prominence is first accelerated mainly by magnetic tension force as well as direct transmission of the shock, and later decelerated mainly by magnetic tension force. The internal flow, on the other hand, is excited during the shock front sweeps through the prominence and damps almost exponentially. We construct a phenomenological model of bulk momentum transfer from the shock to the prominence, which agreed quantitatively with all the simulation results. Based on the phenomenological prominence activation model, we diagnosed physical parameters of the coronal shock wave. The estimated energy of the coronal shock is several percent of the total energy released during the X5.4 flare.

Cloud System Evolution in the Trades—CSET

Science.gov (United States)

Albrecht, B. A.; Zuidema, P.; Bretherton, C. S.; Wood, R.; Ghate, V. P.

2015-12-01

The Cloud System Evolution in the Trades (CSET) study was designed to describe and explain the evolution of the boundary layer aerosol, cloud, and thermodynamic structures along trajectories within the north-Pacific trade-winds. The observational component of this study centered on 7 round-trips made by the NSF NCAR Gulfstream V (GV) between Sacramento, CA and Kona, Hawaii between 1 July and 15 August 2015. The CSET observing strategy used a Lagrangian approach to sample aerosol, cloud, and boundary layer properties upwind from the transition zone over the North Pacific and to resample these areas two days later. GFS forecast trajectories were used to plan the outbound flight to Hawaii and then updated forecast trajectories helped set the return flight plan two days later. Two key elements of the CSET observing system were the newly developed HIAPER Cloud Radar (HCR) and the HIAPER Spectral Resolution Lidar (HSRL). Together they provided unprecedented characterizations of aerosol, cloud and precipitation structures. A full suite of probes on the aircraft were used for in situ measurements of aerosol, cloud, precipitation, and turbulence properties during the low-level aircraft profiling portions of the flights. A wide range of boundary layer structures and aerosol, cloud, and precipitation conditions were observed during CSET. The cloud systems sampled included solid stratocumulus infused with smoke from Canadian wildfires, mesoscale (100-200 km) cloud-precipitation complexes, and patches of shallow cumuli in environments with accumulation mode aerosol concentrations of less than 50 cm-3. Ultra clean layers (UCLs with accumulation mode concentrations of less than 10 cm-3) were observed frequently near the top of the boundary layer and were often associated with shallow, gray (optically thin) layered clouds—features that are the subject of focused investigations by the CSET science team. The extent of aerosol, cloud, drizzle and boundary layer sampling that was

Enforcing Privacy in Cloud Databases

OpenAIRE

Moghadam, Somayeh Sobati; Darmont, Jérôme; Gavin, Gérald

2017-01-01

International audience; Outsourcing databases, i.e., resorting to Database-as-a-Service (DBaaS), is nowadays a popular choice due to the elasticity, availability, scalability and pay-as-you-go features of cloud computing. However, most data are sensitive to some extent, and data privacy remains one of the top concerns to DBaaS users, for obvious legal and competitive reasons.In this paper, we survey the mechanisms that aim at making databases secure in a cloud environment, and discuss current...

SMART POINT CLOUD: DEFINITION AND REMAINING CHALLENGES

Directory of Open Access Journals (Sweden)

F. Poux

2016-10-01

Full Text Available Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

Marine cloud brightening

Science.gov (United States)

Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

2012-01-01

The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action

Cloud Infrastructure & Applications - CloudIA

Science.gov (United States)

Sulistio, Anthony; Reich, Christoph; Doelitzscher, Frank

The idea behind Cloud Computing is to deliver Infrastructure-as-a-Services and Software-as-a-Service over the Internet on an easy pay-per-use business model. To harness the potentials of Cloud Computing for e-Learning and research purposes, and to small- and medium-sized enterprises, the Hochschule Furtwangen University establishes a new project, called Cloud Infrastructure & Applications (CloudIA). The CloudIA project is a market-oriented cloud infrastructure that leverages different virtualization technologies, by supporting Service-Level Agreements for various service offerings. This paper describes the CloudIA project in details and mentions our early experiences in building a private cloud using an existing infrastructure.

ID based cryptography for secure cloud data storage

OpenAIRE

Kaaniche , Nesrine; Boudguiga , Aymen; Laurent , Maryline

2013-01-01

International audience; This paper addresses the security issues of storing sensitive data in a cloud storage service and the need for users to trust the commercial cloud providers. It proposes a cryptographic scheme for cloud storage, based on an original usage of ID-Based Cryptography. Our solution has several advantages. First, it provides secrecy for encrypted data which are stored in public servers. Second, it offers controlled data access and sharing among users, so that unauthorized us...

Mesoscale to Synoptic Scale Cloud Variability

Science.gov (United States)

Rossow, William B.

1998-01-01

The atmospheric circulation and its interaction with the oceanic circulation involve non-linear and non-local exchanges of energy and water over a very large range of space and time scales. These exchanges are revealed, in part, by the related variations of clouds, which occur on a similar range of scales as the atmospheric motions that produce them. Collection of comprehensive measurements of the properties of the atmosphere, clouds and surface allows for diagnosis of some of these exchanges. The use of a multi-satellite-network approach by the International Satellite Cloud Climatology Project (ISCCP) comes closest to providing complete coverage of the relevant range space and time scales over which the clouds, atmosphere and ocean vary. A nearly 15-yr dataset is now available that covers the range from 3 hr and 30 km to decade and planetary. This paper considers three topics: (1) cloud variations at the smallest scales and how they may influence radiation-cloud interactions, and (2) cloud variations at "moderate" scales and how they may cause natural climate variability, and (3) cloud variations at the largest scales and how they affect the climate. The emphasis in this discussion is on the more mature subject of cloud-radiation interactions. There is now a need to begin similar detailed diagnostic studies of water exchange processes.

Fragmentation of rotating protostellar clouds

International Nuclear Information System (INIS)

Tohline, J.E.

1980-01-01

We examine, with a three-dimensional hydrodynamic computer code, the behavior of rotating, isothermal gas clouds as they collapse from Jeans unstable configurations, in order to determine whether they are susceptible to fragmentation during the initial dynamic collapse phase of their evolution. We find that a gas cloud will not fragment unless (a) it begins collapsing from a radius much smaller than the Jeans radius (i.e., the cloud initially encloses many Jeans masses) and (b) irregularities in the cloud's initial structure (specifically, density inhomogeneities) enclose more than one Jeans mass of material. Gas pressure smooths out features that are not initially Jeans unstable while rotation plays no direct role in damping inhomogeneities. Instead of fragmenting, most of our models collapse to a ring configuration (as has been observed by other investigators in two-dimensional, axisymmetric models). The rings appear to be less susceptible to gragmentation from arbitrary perturbations in their structure than has previously been indicated in other work. Because our models, which include the effects of gas pressure, do not readily fragment during a phase of dynamic collapse, we suggest that gas clouds in the galactic disk undergo fragmentation only during quasi-equilibrium phases of their evolution

The International Symposium on Grids and Clouds and the Open Grid Forum

Science.gov (United States)

The International Symposium on Grids and Clouds 20111 was held at Academia Sinica in Taipei, Taiwan on 19th to 25th March 2011. A series of workshops and tutorials preceded the symposium. The aim of ISGC is to promote the use of grid and cloud computing in the Asia Pacific region. Over the 9 years that ISGC has been running, the programme has evolved to become more user community focused with subjects reaching out to a larger population. Research communities are making widespread use of distributed computing facilities. Linking together data centers, production grids, desktop systems or public clouds, many researchers are able to do more research and produce results more quickly. They could do much more if the computing infrastructures they use worked together more effectively. Changes in the way we approach distributed computing, and new services from commercial providers, mean that boundaries are starting to blur. This opens the way for hybrid solutions that make it easier for researchers to get their job done. Consequently the theme for ISGC2011 was the opportunities that better integrated computing infrastructures can bring, and the steps needed to achieve the vision of a seamless global research infrastructure. 2011 is a year of firsts for ISGC. First the title - while the acronym remains the same, its meaning has changed to reflect the evolution of computing: The International Symposium on Grids and Clouds. Secondly the programming - ISGC 2011 has always included topical workshops and tutorials. But 2011 is the first year that ISGC has been held in conjunction with the Open Grid Forum2 which held its 31st meeting with a series of working group sessions. The ISGC plenary session included keynote speakers from OGF that highlighted the relevance of standards for the research community. ISGC with its focus on applications and operational aspects complemented well with OGF's focus on standards development. ISGC brought to OGF real-life use cases and needs to be

THE CALIFORNIA MOLECULAR CLOUD

International Nuclear Information System (INIS)

Lada, Charles J.; Lombardi, Marco; Alves, Joao F.

2009-01-01

We present an analysis of wide-field infrared extinction maps of a region in Perseus just north of the Taurus-Auriga dark cloud complex. From this analysis we have identified a massive, nearby, but previously unrecognized, giant molecular cloud (GMC). Both a uniform foreground star density and measurements of the cloud's velocity field from CO observations indicate that this cloud is likely a coherent structure at a single distance. From comparison of foreground star counts with Galactic models, we derive a distance of 450 ± 23 pc to the cloud. At this distance the cloud extends over roughly 80 pc and has a mass of ∼ 10 5 M sun , rivaling the Orion (A) molecular cloud as the largest and most massive GMC in the solar neighborhood. Although surprisingly similar in mass and size to the more famous Orion molecular cloud (OMC) the newly recognized cloud displays significantly less star formation activity with more than an order of magnitude fewer young stellar objects than found in the OMC, suggesting that both the level of star formation and perhaps the star formation rate in this cloud are an order of magnitude or more lower than in the OMC. Analysis of extinction maps of both clouds shows that the new cloud contains only 10% the amount of high extinction (A K > 1.0 mag) material as is found in the OMC. This, in turn, suggests that the level of star formation activity and perhaps the star formation rate in these two clouds may be directly proportional to the total amount of high extinction material and presumably high density gas within them and that there might be a density threshold for star formation on the order of n(H 2 ) ∼ a few x 10 4 cm -3 .

Optical Instruments Synergy in Determination of Optical Depth of Thin Clouds

Energy Technology Data Exchange (ETDEWEB)

Vladutescu, Daniela V.; Schwartz, Stephen E.

2017-06-25

Optically thin clouds have a strong radiative effect and need to be represented accurately in climate models. Cloud optical depth of thin clouds was retrieved using high resolution digital photography, lidar, and a radiative transfer model. The Doppler Lidar was operated at 1.5 μm, minimizing return from Rayleigh scattering, emphasizing return from aerosols and clouds. This approach examined cloud structure on scales 3 to 5 orders of magnitude finer than satellite products, opening new avenues for examination of cloud structure and evolution.

Study of the Evolution of the Electric Structure of a Convective Cloud Using the Data of a Numerical Nonstationary Three-Dimensional Model

Science.gov (United States)

Veremey, N. E.; Dovgalyuk, Yu. A.; Zatevakhin, M. A.; Ignatyev, A. A.; Morozov, V. N.

2014-04-01

Numerical nonstationary three-dimensional model of a convective cloud with parameterized description of microphysical processes with allowance for the electrization processes is considered. The results of numerical modeling of the cloud evolution for the specified atmospheric conditions are presented. The spatio-temporal distribution of the main cloud characteristics including the volume charge density and the electric field is obtained. The calculation results show that the electric structure of the cloud is different at its various life stages, i.e., it varies from unipolar to dipolar and then to tripolar. This conclusion is in fair agreement with the field studies.

Information Security in the Age of Cloud Computing

Science.gov (United States)

Sims, J. Eric

2012-01-01

Information security has been a particularly hot topic since the enhanced internal control requirements of Sarbanes-Oxley (SOX) were introduced in 2002. At about this same time, cloud computing started its explosive growth. Outsourcing of mission-critical functions has always been a gamble for managers, but the advantages of cloud computing are…

A Cloud Based Data Integration Framework

OpenAIRE

Jiang , Nan; Xu , Lai; Vrieze , Paul ,; Lim , Mian-Guan; Jarabo , Oscar

2012-01-01

Part 7: Cloud-Based Support; International audience; Virtual enterprise (VE) relies on resource sharing and collaboration across geographically dispersed and dynamically allied businesses in order to better respond to market opportunities. It is generally considered that effective data integration and management is crucial to realise the value of VE. This paper describes a cloud-based data integration framework that can be used for supporting VE to discover, explore and respond more emerging ...

Formation of Massive Molecular Cloud Cores by Cloud-cloud Collision

OpenAIRE

Inoue, Tsuyoshi; Fukui, Yasuo

2013-01-01

Recent observations of molecular clouds around rich massive star clusters including NGC3603, Westerlund 2, and M20 revealed that the formation of massive stars could be triggered by a cloud-cloud collision. By using three-dimensional, isothermal, magnetohydrodynamics simulations with the effect of self-gravity, we demonstrate that massive, gravitationally unstable, molecular cloud cores are formed behind the strong shock waves induced by the cloud-cloud collision. We find that the massive mol...

Clouds, Wind and the Biogeography of Central American Cloud Forests: Remote Sensing, Atmospheric Modeling, and Walking in the Jungle

Science.gov (United States)

Lawton, R.; Nair, U. S.

2011-12-01

Cloud forests stand at the core of the complex of montane ecosystems that provide the backbone to the multinational Mesoamerican Biological Corridor, which seeks to protect a biodiversity conservation "hotspot" of global significance in an area of rapidly changing land use. Although cloud forests are generally defined by frequent and prolonged immersion in cloud, workers differ in their feelings about "frequent" and "prolonged", and quantitative assessments are rare. Here we focus on the dry season, in which the cloud and mist from orographic cloud plays a critical role in forest water relations, and discuss remote sensing of orographic clouds, and regional and atmospheric modeling at several scales to quantitatively examine the distribution of the atmospheric conditions that characterize cloud forests. Remote sensing using data from GOES reveals diurnal and longer scale patterns in the distribution of dry season orographic clouds in Central America at both regional and local scales. Data from MODIS, used to calculate the base height of orographic cloud banks, reveals not only the geographic distributon of cloud forest sites, but also striking regional variation in the frequency of montane immersion in orographic cloud. At a more local scale, wind is known to have striking effects on forest structure and species distribution in tropical montane ecosystems, both as a general mechanical stress and as the major agent of ecological disturbance. High resolution regional atmospheric modeling using CSU RAMS in the Monteverde cloud forests of Costa Rica provides quantitative information on the spatial distribution of canopy level winds, insight into the spatial structure and local dynamics of cloud forest communities. This information will be useful in not only in local conservation planning and the design of the Mesoamerican Biological Corridor, but also in assessments of the sensitivity of cloud forests to global and regional climate changes.

Clouds vertical properties over the Northern Hemisphere monsoon regions from CloudSat-CALIPSO measurements

Science.gov (United States)

Das, Subrata Kumar; Golhait, R. B.; Uma, K. N.

2017-01-01

The CloudSat spaceborne radar and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) space-borne lidar measurements, provide opportunities to understand the intriguing behavior of the vertical structure of monsoon clouds. The combined CloudSat-CALIPSO data products have been used for the summer season (June-August) of 2006-2010 to present the statistics of cloud macrophysical (such as cloud occurrence frequency, distribution of cloud top and base heights, geometrical thickness and cloud types base on occurrence height), and microphysical (such as ice water content, ice water path, and ice effective radius) properties of the Northern Hemisphere (NH) monsoon region. The monsoon regions considered in this work are the North American (NAM), North African (NAF), Indian (IND), East Asian (EAS), and Western North Pacific (WNP). The total cloud fraction over the IND (mostly multiple-layered cloud) appeared to be more frequent as compared to the other monsoon regions. Three distinctive modes of cloud top height distribution are observed over all the monsoon regions. The high-level cloud fraction is comparatively high over the WNP and IND. The ice water content and ice water path over the IND are maximum compared to the other monsoon regions. We found that the ice water content has little variations over the NAM, NAF, IND, and WNP as compared to their macrophysical properties and thus give an impression that the regional differences in dynamics and thermodynamics properties primarily cause changes in the cloud frequency or coverage and only secondary in the cloud ice properties. The background atmospheric dynamics using wind and relative humidity from the ERA-Interim reanalysis data have also been investigated which helps in understanding the variability of the cloud properties over the different monsoon regions.

MVC for content management on the cloud

OpenAIRE

McGruder, Crystal A.

2011-01-01

Approved for public release; distribution is unlimited. Cloud computing portrays a new model for providing IT services over the Internet. In cloud computing, resources are accessed from the Internet through web-based tools. Although cloud computing offers reduced cost, increased storage, high automation, flexibility, mobility, and the ability of IT to shift focus, there are other concerns such as the management, organization and structure of content on the cloud that large organizations sh...

Retrieving latent heating vertical structure from cloud and precipitation profiles—Part II: Deep convective and stratiform rain processes

International Nuclear Information System (INIS)

Li, Rui; Min, Qilong; Wu, Xiaoqing; Fu, Yunfei

2013-01-01

An exploratory study on physical based latent heat (LH) retrieval algorithm is conducted by parameterizing the physical linkages between observed cloud and precipitation profiles to the major processes of phase change of atmospheric water. Specifically, rain is segregated into three rain types: warm, convective, and stratiform rain, based on their dynamical and thermodynamical characteristics. As the second of series, both convective and stratiform rain LH algorithms are presented and evaluated here. For convective and stratiform rain, the major LH-related microphysical processes including condensation, deposition, evaporation, sublimation, and freezing–melting are parameterized with the aid of Cloud Resolving Model (CRM) simulations. The condensation and deposition processes are parameterized in terms of rain formation processes through the precipitation formation theory. LH associated with the freezing–melting process is relatively small and is assumed to be a fraction of total condensation and deposition LH. The evaporation and sublimation processes are parameterized for three unsaturated scenarios: rain out of the cloud body, clouds at cloud boundary and clouds and rain in downdraft region. The evaluation or self-consistency test indicates the retrievals capture the major features of LH profiles and reproduce the double peaks at right altitudes. The LH products are applicable at various stages of cloud system life cycle for high-resolution models, as well as for large-scale climate models. -- Highlights: ► An exploratory study on physics-based cold rain latent heat retrieval algorithm. ► Utilize the full information of the vertical structures of cloud and rainfall. ► Include all major LH-related microphysical processes (in ice and liquid phase). ► Directly link water mass measurements to latent heat at instantaneous pixel level. ► Applicable at various stages of cloud system life cycle

Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

OpenAIRE

Y. Liu; W. Wu; M. P. Jensen; T. Toto

2011-01-01

This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surfaced-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fractio...

A reexamination and extension of international strategy-structure theory

OpenAIRE

Wolf, Joachim; Egelhoff, William G.

2001-01-01

Using a sample of 95 German firms, the study finds general support for the traditional fits of international strategy-structure theory. Employing an information-processing perspective, the study conceptually and empirically extends existing theory (1) to address strategy-structure fit for various types of matrix structure, and (2) by adding two new elements of international strategy to the existing international strategy-structure model: the level of international transfers and level of forei...

How chemistry influences cloud structure, star formation, and the IMF

NARCIS (Netherlands)

Hocuk, S.; Cazaux, S.; Spaans, M.; Caselli, P.

2016-01-01

In the earliest phases of star-forming clouds, stable molecular species, such as CO, are important coolants in the gas phase. Depletion of these molecules on dust surfaces affects the thermal balance of molecular clouds and with that their whole evolution. For the first time, we study the effect of

Near Real Time Structural Health Monitoring with Multiple Sensors in a Cloud Environment

Science.gov (United States)

Bock, Y.; Todd, M.; Kuester, F.; Goldberg, D.; Lo, E.; Maher, R.

2017-12-01

A repeated near real time 3-D digital surrogate representation of critical engineered structures can be used to provide actionable data on subtle time-varying displacements in support of disaster resiliency. We describe a damage monitoring system of optimally-integrated complementary sensors, including Global Navigation Satellite Systems (GNSS), Micro-Electro-Mechanical Systems (MEMS) accelerometers coupled with the GNSS (seismogeodesy), light multi-rotor Unmanned Aerial Vehicles (UAVs) equipped with high-resolution digital cameras and GNSS/IMU, and ground-based Light Detection and Ranging (LIDAR). The seismogeodetic system provides point measurements of static and dynamic displacements and seismic velocities of the structure. The GNSS ties the UAV and LIDAR imagery to an absolute reference frame with respect to survey stations in the vicinity of the structure to isolate the building response to ground motions. The GNSS/IMU can also estimate the trajectory of the UAV with respect to the absolute reference frame. With these constraints, multiple UAVs and LIDAR images can provide 4-D displacements of thousands of points on the structure. The UAV systematically circumnavigates the target structure, collecting high-resolution image data, while the ground LIDAR scans the structure from different perspectives to create a detailed baseline 3-D reference model. UAV- and LIDAR-based imaging can subsequently be repeated after extreme events, or after long time intervals, to assess before and after conditions. The unique challenge is that disaster environments are often highly dynamic, resulting in rapidly evolving, spatio-temporal data assets with the need for near real time access to the available data and the tools to translate these data into decisions. The seismogeodetic analysis has already been demonstrated in the NASA AIST Managed Cloud Environment (AMCE) designed to manage large NASA Earth Observation data projects on Amazon Web Services (AWS). The Cloud provides

Cloud cover over the equatorial eastern Pacific derived from July 1983 International Satellite Cloud Climatology Project data using a hybrid bispectral threshold method

Science.gov (United States)

Minnis, Patrick; Harrison, Edwin F.; Gibson, Gary G.

1987-01-01

A set of visible and IR data obtained with GOES from July 17-31, 1983 is analyzed using a modified version of the hybrid bispectral threshold method developed by Minnis and Harrison (1984). This methodology can be divided into a set of procedures or optional techniques to determine the proper contaminate clear-sky temperature or IR threshold. The various optional techniques are described; the options are: standard, low-temperature limit, high-reflectance limit, low-reflectance limit, coldest pixel and thermal adjustment limit, IR-only low-cloud temperature limit, IR clear-sky limit, and IR overcast limit. Variations in the cloud parameters and the characteristics and diurnal cycles of trade cumulus and stratocumulus clouds over the eastern equatorial Pacific are examined. It is noted that the new method produces substantial changes in about one third of the cloud amount retrieval; and low cloud retrievals are affected most by the new constraints.

A Velocity Structure Analysis of Giant Molecular Cloud Associated with HII Region S152

Directory of Open Access Journals (Sweden)

Woo-Yeol Choi

2005-06-01

Full Text Available S152 is a small bright emission nebula located in the Perseus arm. Its optical diameter corresponds to 1.5 pc for an adopted distance 3.5 kpc. However, S152 is a part of a giant molecular cloud complex, which consists of several dense cores, containing active star-forming sites, and well aligned arm-like features. We analyzed the FCRAO 12CO (J = 1→0 Outer Galaxy Survey data in this region to study the kinematical structure of this region, which resembles a big ``scorpion". We found that there exist three different velocity components, about --54.5, --50.4, --48.8 km s-1, depending on the position of the ``scorpion". There also exist velocity gradients of 0.21 km s-1 pc-1 and 0.16 km s-1 pc-1 through the whole extent of the ``scorpion". Interestingly, these two velocity gradients show an opposite direction with each other. It is likely that the velocity structure of this region may result from the mergence of different gas clouds, and the interaction with the SNR 109.1-1.0 occurred later, mostly at the region around the ``head of the scorpion" only.

Quantifying Biomass from Point Clouds by Connecting Representations of Ecosystem Structure

Science.gov (United States)

Hendryx, S. M.; Barron-Gafford, G.

2017-12-01

Quantifying terrestrial ecosystem biomass is an essential part of monitoring carbon stocks and fluxes within the global carbon cycle and optimizing natural resource management. Point cloud data such as from lidar and structure from motion can be effective for quantifying biomass over large areas, but significant challenges remain in developing effective models that allow for such predictions. Inference models that estimate biomass from point clouds are established in many environments, yet, are often scale-dependent, needing to be fitted and applied at the same spatial scale and grid size at which they were developed. Furthermore, training such models typically requires large in situ datasets that are often prohibitively costly or time-consuming to obtain. We present here a scale- and sensor-invariant framework for efficiently estimating biomass from point clouds. Central to this framework, we present a new algorithm, assignPointsToExistingClusters, that has been developed for finding matches between in situ data and clusters in remotely-sensed point clouds. The algorithm can be used for assessing canopy segmentation accuracy and for training and validating machine learning models for predicting biophysical variables. We demonstrate the algorithm's efficacy by using it to train a random forest model of above ground biomass in a shrubland environment in Southern Arizona. We show that by learning a nonlinear function to estimate biomass from segmented canopy features we can reduce error, especially in the presence of inaccurate clusterings, when compared to a traditional, deterministic technique to estimate biomass from remotely measured canopies. Our random forest on cluster features model extends established methods of training random forest regressions to predict biomass of subplots but requires significantly less training data and is scale invariant. The random forest on cluster features model reduced mean absolute error, when evaluated on all test data in leave

Statistical thermodynamics and the size distributions of tropical convective clouds.

Science.gov (United States)

Garrett, T. J.; Glenn, I. B.; Krueger, S. K.; Ferlay, N.

2017-12-01

Parameterizations for sub-grid cloud dynamics are commonly developed by using fine scale modeling or measurements to explicitly resolve the mechanistic details of clouds to the best extent possible, and then to formulating these behaviors cloud state for use within a coarser grid. A second is to invoke physical intuition and some very general theoretical principles from equilibrium statistical thermodynamics. This second approach is quite widely used elsewhere in the atmospheric sciences: for example to explain the heat capacity of air, blackbody radiation, or even the density profile or air in the atmosphere. Here we describe how entrainment and detrainment across cloud perimeters is limited by the amount of available air and the range of moist static energy in the atmosphere, and that constrains cloud perimeter distributions to a power law with a -1 exponent along isentropes and to a Boltzmann distribution across isentropes. Further, the total cloud perimeter density in a cloud field is directly tied to the buoyancy frequency of the column. These simple results are shown to be reproduced within a complex dynamic simulation of a tropical convective cloud field and in passive satellite observations of cloud 3D structures. The implication is that equilibrium tropical cloud structures can be inferred from the bulk thermodynamic structure of the atmosphere without having to analyze computationally expensive dynamic simulations.

Making Cloud-based Systems Elasticity Testing Reproducible

OpenAIRE

Albonico , Michel; Mottu , Jean-Marie; Sunyé , Gerson; Alvares , Frederico

2017-01-01

International audience; Elastic cloud infrastructures vary computational resources at runtime, i. e., elasticity, which is error-prone. That makes testing throughout elasticity crucial for those systems. Those errors are detected thanks to tests that should run deterministically many times all along the development. However, elasticity testing reproduction requires several features not supported natively by the main cloud providers, such as Amazon EC2. We identify three requirements that we c...

MCloud: Secure Provenance for Mobile Cloud Users

Science.gov (United States)

2016-10-03

Feasibility of Smartphone Clouds, 2015 15th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid). 04-MAY- 15, Shenzhen, China...compromised kernel, with the highest privilege. MCloud context data gathered by smartphone sensors can now be relayed correctly and with integrity...aspects of people’s daily online and physical activities. Yet, in critical settings it is especially difficult to ascertain and assert an acceptable level

Interconnection Structures, Management and Routing Challenges in Cloud-Service Data Center Networks: A Survey

Directory of Open Access Journals (Sweden)

Ahmad Nahar Quttoum

2018-01-01

Full Text Available Today’s data center networks employ expensive networking equipments in associated structures that were not designed to meet the increasing requirements of the current large-scale data center services. Limitations that vary between reliability, resource utilization, and high costs are challenging. The era of cloud computing represents a promise to enable large-scale data centers. Computing platforms of such cloud service data centers consist of large number of commodity low-price servers that, with a theme of virtualization on top, can meet the performance of the expensive high-level servers at only a fraction of the price. Recently, the research in data center networks started to evolve rapidly. This opened the path for addressing many of its design and management challenges, these like scalability, reliability, bandwidth capacities, virtual machines’ migration, and cost. Bandwidth resource fragmentation limits the network agility, and leads to low utilization rates, not only for the bandwidth resources, but also for the servers that run the applications. With Traffic Engineering methods, managers of such networks can adapt for rapid changes in the network traffic among their servers, this can help to provide better resource utilization and lower costs. The market is going through exciting changes, and the need to run demanding-scale services drives the work toward cloud networks. These networks that are enabled by the notation of autonomic management, and the availability of commodity low-price network equipments. This work provides the readers with a survey that presents the management challenges, design and operational constraints of the cloud-service data center networks

Semantic-less Breach Detection of Polymorphic Malware in Federated Cloud

OpenAIRE

Yahav Biran; George Collins; Borky John M; Joel Dubow

2017-01-01

Cloud computing is one of the largest emerging utility services that is expected to grow enormously over the next decade. Many organizations are moving into hybrid cloud/hosted computing models. Single cloud service provider introduces cost and environmental challenges. Also, multi-cloud solution implemented by the Cloud tenant is suboptimal as it requires expensive adaptation costs. Cloud Federation is a useful structure for aggregating cloud based services under a single umbrella to share r...

Two cloud-point phenomena in tetrabutylammonium perfluorooctanoate aqueous solutions: anomalous temperature-induced phase and structure transitions.

Science.gov (United States)

Yan, Peng; Huang, Jin; Lu, Run-Chao; Jin, Chen; Xiao, Jin-Xin; Chen, Yong-Ming

2005-03-24

This paper reported the phase behavior and aggregate structure of tetrabutylammonium perfluorooctanoate (TBPFO), determined by differential scanning calorimeter, electrical conductivity, static/dynamic light scattering, and rheology methods. We found that above a certain concentration the TBPFO solution showed anomalous temperature-dependent phase behavior and structure transitions. Such an ionic surfactant solution exhibits two cloud points. When the temperature was increased, the solution turned from a homogeneous-phase to a liquid-liquid two-phase system, then to another homogeneous-phase, and finally to another liquid-liquid two-phase system. In the first homogeneous-phase region, the aggregates of TBPFO were rodlike micelles and the solution was Newtonian fluid. While in the second homogeneous-phase region, the aggregates of TBPFO were large wormlike micelles, and the solution behaved as pseudoplastic fluid that also exhibited viscoelastic behavior. We thought that the first cloud point might be caused by the "bridge" effect of the tetrabutylammonium counterion between the micelles and the second one by the formation of the micellar network.

Organizational Structures that Support Internal Program Evaluation

Science.gov (United States)

Lambur, Michael T.

2008-01-01

This chapter explores how the structure of large complex organizations such as Cooperative Extension affects their ability to support internal evaluation of their programs and activities. Following a literature review of organizational structure and its relation to internal evaluation capacity, the chapter presents the results of interviews with…

Molecular Clouds, Star Formation and Galactic Structure.

Science.gov (United States)

Scoville, Nick; Young, Judith S.

1984-01-01

Radio observations show that the gigantic clouds of molecules where stars are born are distributed in various ways in spiral galaxies, perhaps accounting for the variation in their optical appearance. Research studies and findings in this area are reported and discussed. (JN)

Impact of aerosol intrusions on sea-ice melting rates and the structure Arctic boundary layer clouds

Science.gov (United States)

Cotton, W.; Carrio, G.; Jiang, H.

2003-04-01

The Los Alamos National Laboratory sea-ice model (LANL CICE) was implemented into the real-time and research versions of the Colorado State University-Regional Atmospheric Modeling System (RAMS@CSU). The original version of CICE was modified in its structure to allow module communication in an interactive multigrid framework. In addition, some improvements have been made in the routines involved in the coupling, among them, the inclusion of iterative methods that consider variable roughness lengths for snow-covered ice thickness categories. This version of the model also includes more complex microphysics that considers the nucleation of cloud droplets, allowing the prediction of mixing ratios and number concentrations for all condensed water species. The real-time version of RAMS@CSU automatically processes the NASA Team SSMI F13 25km sea-ice coverage data; the data are objectively analyzed and mapped to the model grid configuration. We performed two types of cloud resolving simulations to assess the impact of the entrainment of aerosols from above the inversion on Arctic boundary layer clouds. The first series of numerical experiments corresponds to a case observed on May 4 1998 during the FIRE-ACE/SHEBA field experiment. Results indicate a significant impact on the microstructure of the simulated clouds. When assuming polluted initial profiles above the inversion, the liquid water fraction of the cloud monotonically decreases, the total condensate paths increases and downward IR tends to increase due to a significant increase in the ice water path. The second set of cloud resolving simulations focused on the evaluation of the potential effect of aerosol concentration above the inversion on melting rates during spring-summer period. For these multi-month simulations, the IFN and CCN profiles were also initialized assuming the 4 May profiles as benchmarks. Results suggest that increasing the aerosol concentrations above the boundary layer increases sea-ice melting

Structure shielding from cloud and fallout gamma ray sources for assessing the consequences of reactor accidents

International Nuclear Information System (INIS)

Burson, Z.G.; Profio, A.E.

1975-12-01

Radiation shielding provided by transportation vehicles and structures typical of where people live and work were estimated for cloud and fallout gamma-ray sources resulting from a hypothetical reactor accident. Dose reduction factors are recommended for a variety of situations for realistically assessing the consequences of reactor accidents

Potential profiles obtained from applied dust cloud perturbations

International Nuclear Information System (INIS)

Thomas, Edward Jr.

2002-01-01

This paper details an experimental investigation of the local potential structure within a cloud of suspended microparticles - a 'dusty' or 'complex' plasma - using particle image velocimetry (PIV) techniques. Applied perturbations, synchronized to the PIV measurements, are used to force a cloud of suspended microparticles to become unconfined. From the free-streaming motion of the particles during the loss of confinement and subsequent reformation of the dust cloud, an analysis of the potential is performed. Furthermore, a new method of analyzing the potential structure from the motion of free-streaming microparticles in the plasma is presented

Retrieving latent heating vertical structure from cloud and precipitation Profiles—Part I: Warm rain processes

International Nuclear Information System (INIS)

Min, Qilong; Li, Rui; Wu, Xiaoqing; Fu, Yunfei

2013-01-01

An exploratory study on physical based latent heat (LH) retrieval algorithm is conducted by parameterizing the physical linkages of hydrometeor profiles of cloud and precipitation to the major processes related to the phase change of atmospheric water. Specifically, rain events are segregated into three rain types: warm, convective, and stratiform, based on their dynamical and thermodynamical characteristics. As the first of the series, only the warm rain LH algorithm is presented and evaluated here. The major microphysical processes of condensation and evaporation for warm rain are parameterized through traditional rain growth theory, with the aid of Cloud Resolving Model (CRM) simulations. The evaluation or the self-consistency tests indicate that the physical based retrievals capture the fundamental LH processes associated with the warm rain life cycle. There is no significant systematic bias in terms of convection strength, illustrated by the month-long CRM simulation as the mesoscale convective systems (MCSs) experience from initial, mature, to decay stages. The overall monthly-mean LH comparison showed that the total LH, as well as condensation heating and evaporation cooling components, agree with the CRM simulation. -- Highlights: ► An exploratory study on physics-based warm rain latent heat retrieval algorithm. ► Utilize the full information of the vertical structures of cloud and rainfall. ► Directly link water mass measurements to latent heat at instantaneous pixel level. ► Applicable at various stages of cloud system life cycle

Cloud-Top Entrainment in Stratocumulus Clouds

Science.gov (United States)

Mellado, Juan Pedro

2017-01-01

Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

Composition and structure of fresh ammonia clouds on Jupiter based on quantitative analysis of Galileo/NIMS and New Horizons/LEISA spectra

Science.gov (United States)

Sromovsky, L. A.; Fry, P. M.

2018-06-01

Ammonia gas has long been assumed to be the main source of condensables for the upper cloud layer on Jupiter, but distinctive spectral features associated with ammonia have been seen only rarely. Since both ammonia and NH4SH absorb in the 3 μm region, and widespread absorption in the 3 μm region was present (Sromovsky and Fry, 2010), identification of the 2 μm absorption feature of NH3 provided an opportunity to clearly establish its presence in Jovian clouds. Baines et al. (2002) succeeded in finding in Near Infrared Mapping Spectrometer (NIMS) observations one feature that had both 2 μm and 3 μm absorption, and many which were known to have absorption at 2.73 μm. They named these Spectrally Identifiable Ammonia Clouds (SIACs). They also argued that these were fresh ammonia clouds that would eventually succumb to some process that would obscure their absorption features. Detection of many more of the 2 μm features was later achieved by New Horizon's Linear Etalon Imaging Spectral Array (LEISA) instrument, which provided both the spatial and spectral resolution needed to identify these features. Here we report on the first quantitative modeling that uses NIMS spectra over a broad (1-5.2 μm) spectral range and LEISA spectra over a much narrower (1.25-2.5 μm) spectral range to constrain the cloud structure and composition of these rare cloud features and compare them to background clouds. We find that the absorption signature at 2 μm, which is well characterized in LEISA spectra, is relatively subtle and easily matched by model clouds containing spherical particles of ammonia ice with radii of 2-4 μm. The NIMS spectra, which cover both reflected sunlight as well as thermal emission regions are more difficult to model with cloud materials plausibly present in Jupiter's atmosphere. The best signal/noise spectra obtained from NIMS provide a relatively sparse sampling of the spectrum, which does not establish the detailed shape of the 3 μm absorption region

The Impact Of Cloud Computing Technology On The Audit Process And The Audit Profession

OpenAIRE

Yati Nurhajati

2015-01-01

In the future cloud computing audits will become increasingly The use of that technology has influenced of the audit process and be a new challenge for both external and the Internal Auditors to understand IT and learn how to use cloud computing and cloud services that hire in cloud service provider CSP and considering the risks of cloud computing and how to audit cloud computing by risk based audit approach. The wide range of unique risks and depend on the type and model of the cloud soluti...

DIDACTIC POTENTIAL OF CLOUD TECHNOLOGIES FOR MENAGMENT OF EDUCATIONAL INSTITUTION

Directory of Open Access Journals (Sweden)

А А Заславский

2016-12-01

Full Text Available The article introduces the basic definitions and differences between Services in the cloud, cloud services, cloud applications and cloud storage data. The basic cloud types that can be used on the Internet and the LAN of educational organization (Intranet. Possibilities of use of cloud services to improve of effective management at educational organization of internal and external communications of educational organizations, as well as to ensure joint work of employees of the educational organization.A list of core competencies an employee of an educational organization, which will be developed for use in the activity of cloud services and cloud applications. We describe the positive aspects of the use of cloud services and cloud-based technologies for the management of the educational institution, identifies possible risks of using cloud technologies, presents options for the use of cloud technology over the Internet and the Intranet network. We present a list of software included with every category of cloud services described types: storage and file synchronization, storage of bookmarks and notes, time management, software applications. At the article is introduced the basic definition and classification of cloud services, offered examples of methodical use of cloud services in the management of the educational organization.

A comparison of shock-cloud and wind-cloud interactions: effect of increased cloud density contrast on cloud evolution

Science.gov (United States)

Goldsmith, K. J. A.; Pittard, J. M.

2018-05-01

The similarities, or otherwise, of a shock or wind interacting with a cloud of density contrast χ = 10 were explored in a previous paper. Here, we investigate such interactions with clouds of higher density contrast. We compare the adiabatic hydrodynamic interaction of a Mach 10 shock with a spherical cloud of χ = 103 with that of a cloud embedded in a wind with identical parameters to the post-shock flow. We find that initially there are only minor morphological differences between the shock-cloud and wind-cloud interactions, compared to when χ = 10. However, once the transmitted shock exits the cloud, the development of a turbulent wake and fragmentation of the cloud differs between the two simulations. On increasing the wind Mach number, we note the development of a thin, smooth tail of cloud material, which is then disrupted by the fragmentation of the cloud core and subsequent `mass-loading' of the flow. We find that the normalized cloud mixing time (tmix) is shorter at higher χ. However, a strong Mach number dependence on tmix and the normalized cloud drag time, t_{drag}^' }, is not observed. Mach-number-dependent values of tmix and t_{drag}^' } from comparable shock-cloud interactions converge towards the Mach-number-independent time-scales of the wind-cloud simulations. We find that high χ clouds can be accelerated up to 80-90 per cent of the wind velocity and travel large distances before being significantly mixed. However, complete mixing is not achieved in our simulations and at late times the flow remains perturbed.

Cloud Computing, Tieto Cloud Server Model

OpenAIRE

Suikkanen, Saara

2013-01-01

The purpose of this study is to find out what is cloud computing. To be able to make wise decisions when moving to cloud or considering it, companies need to understand what cloud is consists of. Which model suits best to they company, what should be taken into account before moving to cloud, what is the cloud broker role and also SWOT analysis of cloud? To be able to answer customer requirements and business demands, IT companies should develop and produce new service models. IT house T...

Collapse and equilibrium of rotating, adiabatic clouds

International Nuclear Information System (INIS)

Boss, A.P.

1980-01-01

A numerical hydrodynamics computer code has been used to follow the collapse and establishment of equilibrium of adiabatic gas clouds restricted to axial symmetry. The clouds are initially uniform in density and rotation, with adiabatic exponents γ=5/3 and 7/5. The numerical technique allows, for the first time, a direct comparison to be made between the dynamic collapse and approach to equilibrium of unconstrained clouds on the one hand, and the results for incompressible, uniformly rotating equilibrium clouds, and the equilibrium structures of differentially rotating polytropes, on the other hand

Evolution Of The Cloud Field And Wind Structure Of Ntb Disturbance

Science.gov (United States)

Barrado-Izagirre, Naiara; Pérez-Hoyos, S.; García-Melendo, E.; Sánchez-Lavega, A.

2009-09-01

The banded visual aspect of cloud patterns in Jupiter hides markedly turbulent areas visible in high resolution images. The North Temperate Belt (NTB) at 21° N planetocentric latitude where the most intense Jovian jet resides (with speeds of 160 - 180 m/s) is a region of particular interest because it is known to suffer almost every 15 years an eruption or disturbance which dramatically changes its appearance. This phenomenon is known as NTB Disturbance (NTBD). The last one of such disturbances happened in 2007 and was captured by the Hubble Space Telescope and with lower resolution by the "International Outer Planet Watch” (IOPW) network [Sánchez-Lavega et al., 2008. Depth of a strong Jovian jet from a planetary-scale disturbance driven by storms, Nature 451.]. In this work we make use of these observations to characterize the morphology of the disturbed cloud field in the wake of the plumes which originated the perturbation. This is done mostly in terms of the brightness spectral distribution in order to characterize the typical spatial frequency of the perturbation and its wavy and turbulent nature. In addition we make a comparison of the jet profile in the NTB just after the disturbance ended (June 2007) with one obtained year later (July 2008). It shows that a change occurred in its anticyclonic side producing a reinforced westward jet at 17°N with a speed change of 30 m/s. Acknowledgments: This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07

Changes in forest structure and composition after fire in tropical montane cloud forests near the Andean treeline

NARCIS (Netherlands)

Oliveras Menor, I.; Malhi, Y.; Salinas, N.; Huaman, V.; Urquiaga-Flores, E.; Kala-Mamani, J.; Quintano-Loaiza, J.A.; Cuba-Torres, I.; Lizarraga-Morales, N.; Roman-Cuesta, R.M.

2014-01-01

Background: In tropical montane cloud forests (TMCFs) fires can be a frequent source of disturbance near the treeline. Aims: To identify how forest structure and tree species composition change in response to fire and to identify fire-tolerant species, and determine which traits or characteristics

Conditions of external loading of nuclear power plant structures by vapor cloud explosions and design requirements

International Nuclear Information System (INIS)

Geiger, W.

1977-01-01

In the design of nuclear power plant structures in the Federal Republic of Germany (FRG) the external loading by pressure waves from unconfined vapor cloud explosions is taken into account. The loading conditions used are based on simplified model considerations for the sequence of events which generates the pressure wave. The basic assumption is that the explosion of unconfined vapor clouds can evolve only in the form of a deflagration wave with a maximum overpressure of 0.3 bar. The research on gas explosions conducted in the FRG with a view to external reactor safety just as similar work in other countries demonstrates that there are still various problems which need further clarification. The principal issues are the maximum conceivable load and the modes of structrual response. This paper presents the main results of a status report commissioned by the German Ministry of the Inertior in which the whole sequence of events leading to the external loading of nuclear power plants and the corresponding response of the structure was scrutinized. Constitutive in establishing the status report have been thorough discussions with experts of the various fields. The following problem areas are discussed in the paper. Incidents leading to the release of large amounts of liquefied gas; Formation of explosive vapor clouds, ignition conditions; Development of the explosion, generation of the pressure wave; Interaction between pressure wave and reactor building. It is outlined where definite statements are possible and where uncertainties and information gaps exist. (Auth.)

AP-Cloud: Adaptive Particle-in-Cloud method for optimal solutions to Vlasov–Poisson equation

International Nuclear Information System (INIS)

Wang, Xingyu; Samulyak, Roman; Jiao, Xiangmin; Yu, Kwangmin

2016-01-01

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes of computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.

Star-Forming Clouds Feed, Churn, and Fall

Science.gov (United States)

Kohler, Susanna

2017-12-01

clouds, the authors zoom in and explore three clouds in high-resolution to learn more about the details.Watching Clouds EvolveIbez-Meja and collaborators find that mass accretion occurring after the molecular clouds form plays an important role in the clouds evolution, increasing the mass available to form stars and carrying kinetic energy into the cloud. The accretion process is driven both by background turbulent flows and gravitational attraction as the cloud draws in the gas in its nearby environment.Plots of the cloud mass and radius (top) and mass accretion rate (bottom) for one of the three zoomed-in clouds, shown as a function of time over the 10-Myr simulation. [Adapted from Ibez-Meja et al. 2017]The simulations show that nearby supernovae have two opposing effects on a cloud. On one hand, the blast waves from supernovae compress the envelope of the cloud, increasing the instantaneous rate of accretion. On the other hand, the blast waves disrupt parts of the envelope and erode mass from the clouds surface, decreasing accretion overall. These events ensure that the mass accretion rate of molecular clouds is non-uniform, regularly punctuated by sporadic increases and decreases as the clouds are battered by nearby explosions.Lastly, Ibez-Meja and collaborators show that mass accretion alone isnt enough to power the turbulent internal motions we observe inside molecular clouds. Instead, they conclude, the cloud motions must be primarily powered by gravitational potential energy being converted into kinetic energy as the cloud contracts.The authors simulations therefore show that molecular clouds exist in a state of precarious balance, prevented from collapsing by internal turbulence driven by interactions with their environment and by their own contraction. These results give us an intriguing glimpse into the complex environments in which stars are born.BonusCheck out the animated figure below, which displays how the clouds in the authors simulations evolve over the

Manifestations of electric currents in interstellar molecular clouds

International Nuclear Information System (INIS)

Carlqvist, P.; Gahm, G.F.

1991-12-01

We draw the attention to filamentary structures in molecular clouds and point out the existence of subfilaments of sinusoidal shape and also of helix-like structures. For two dark clouds, the Lynds 204 complex and the Sandqvist 187-188 complex (The Norma 'sword') we make a detailed study of such shapes and in addition we find the possible existence of helices wound around the main filaments. All these features are highly reminiscent of morphologies encountered in solar ascending prominences and in experiments in plasma physics and suggest the existence of electric currents and magnetic fields in these clouds. On the basis of a generalization of the Bennett pinch model, we derive the magnitudes of the currents expected to flow in the filaments. Values of column densities, magnetic field strengths, and direction of the fields are derived from observations. Magnetic fields with both toroidal and axial components are considered. This study shows that axial currents of the order of a few times 10 13 A are necessary for the clouds to be in equilibrium. The corresponding mean current densities are very small and even at the very low values of the fractional abundance of electrons encountered in these clouds, the mean electron velocities are of the order of 10 -2 -10 -5 m s -1 , much lower than the thermal velocities in the clouds. We suggest that helical structures may evolve as a result of various instabilities in the pinched clouds. We also call the attention to the kink intability in connection with the sinusoidal shapes. The existence of electromagnetically controlled features in the interstellar clouds can be tested by further observations. (au)

Automatic registration of Iphone images to LASER point clouds of the urban structures using shape features

Directory of Open Access Journals (Sweden)

B. Sirmacek

2013-10-01

Full Text Available Fusion of 3D airborne laser (LIDAR data and terrestrial optical imagery can be applied in 3D urban modeling and model up-dating. The most challenging aspect of the fusion procedure is registering the terrestrial optical images on the LIDAR point clouds. In this article, we propose an approach for registering these two different data from different sensor sources. As we use iPhone camera images which are taken in front of the interested urban structure by the application user and the high resolution LIDAR point clouds of the acquired by an airborne laser sensor. After finding the photo capturing position and orientation from the iPhone photograph metafile, we automatically select the area of interest in the point cloud and transform it into a range image which has only grayscale intensity levels according to the distance from the image acquisition position. We benefit from local features for registering the iPhone image to the generated range image. In this article, we have applied the registration process based on local feature extraction and graph matching. Finally, the registration result is used for facade texture mapping on the 3D building surface mesh which is generated from the LIDAR point cloud. Our experimental results indicate possible usage of the proposed algorithm framework for 3D urban map updating and enhancing purposes.

Dusty Cloud Acceleration by Radiation Pressure in Rapidly Star-forming Galaxies

Science.gov (United States)

Zhang, Dong; Davis, Shane W.; Jiang, Yan-Fei; Stone, James M.

2018-02-01

We perform two-dimensional and three-dimensional radiation hydrodynamic simulations to study cold clouds accelerated by radiation pressure on dust in the environment of rapidly star-forming galaxies dominated by infrared flux. We utilize the reduced speed of light approximation to solve the frequency-averaged, time-dependent radiative transfer equation. We find that radiation pressure is capable of accelerating the clouds to hundreds of kilometers per second while remaining dense and cold, consistent with observations. We compare these results to simulations where acceleration is provided by entrainment in a hot wind, where the momentum injection of the hot flow is comparable to the momentum in the radiation field. We find that the survival time of the cloud accelerated by the radiation field is significantly longer than that of a cloud entrained in a hot outflow. We show that the dynamics of the irradiated cloud depends on the initial optical depth, temperature of the cloud, and intensity of the flux. Additionally, gas pressure from the background may limit cloud acceleration if the density ratio between the cloud and background is ≲ {10}2. In general, a 10 pc-scale optically thin cloud forms a pancake structure elongated perpendicular to the direction of motion, while optically thick clouds form a filamentary structure elongated parallel to the direction of motion. The details of accelerated cloud morphology and geometry can also be affected by other factors, such as the cloud lengthscale, reduced speed of light approximation, spatial resolution, initial cloud structure, and dimensionality of the run, but these have relatively little affect on the cloud velocity or survival time.

Cosmic ray decreases affect atmospheric aerosols and clouds

DEFF Research Database (Denmark)

Svensmark, Henrik; Bondo, Torsten; Svensmark, J.

2009-01-01

Close passages of coronal mass ejections from the sun are signaled at the Earth's surface by Forbush decreases in cosmic ray counts. We find that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can...... diminish by as much as 7%. Cloud water content as gauged by the Special Sensor Microwave/Imager (SSM/I) reaches a minimum ≈7 days after the Forbush minimum in cosmic rays, and so does the fraction of low clouds seen by the Moderate Resolution Imaging Spectroradiometer (MODIS) and in the International...

Virtualized cloud data center networks issues in resource management

CERN Document Server

Tsai, Linjiun

2016-01-01

This book discusses the characteristics of virtualized cloud networking, identifies the requirements of cloud network management, and illustrates the challenges in deploying virtual clusters in multi-tenant cloud data centers. The book also introduces network partitioning techniques to provide contention-free allocation, topology-invariant reallocation, and highly efficient resource utilization, based on the Fat-tree network structure. Managing cloud data center resources without considering resource contentions among different cloud services and dynamic resource demands adversely affects the performance of cloud services and reduces the resource utilization of cloud data centers. These challenges are mainly due to strict cluster topology requirements, resource contentions between uncooperative cloud services, and spatial/temporal data center resource fragmentation. Cloud data center network resource allocation/reallocation which cope well with such challenges will allow cloud services to be provisioned with ...

Spiral structure and star formation. II. Stellar lifetimes and cloud kinematics

International Nuclear Information System (INIS)

Hausman, M.A.; Roberts, W.W. Jr.

1984-01-01

We present further results of our model, introduced in Paper I, of star formation and star-gas interactions in the cloud-dominated ISMs of spiral density wave galaxies. The global density distribution and velocity field of the gas clouds are virtually independent of stellar parameters and even of mean free path for the wide range of values studied, but local density variations are found which superficially resemble cloud complexes. Increasing the average life span of ''spiral tracer'' stellar associations beyond about 20 Myr washes out the spiral pattern which younger associations show. Allowing clouds to form several successive associations (sequential star formation) slightly increases the frequency of interarm, young-star spurs and substantially increases the average star formation rate. The mean velocity field of clouds shows tipped oval streamlines, similar to both continuum gas dynamical models and stellar-kinematic models of spiral density waves. These streamlines are almost ballistic orbits except close to the spiral arms. Newly formed stellar associations leave the spiral density peak with initial tangential velocitie shigher than ''postshock'' values and do not fall back into the ''preshock'' region. By varying our stellar parametes within physically reasonable limits, we may reproduce spiral galaxies with a wide range of morphological appearaces

+Cloud: An Agent-Based Cloud Computing Platform

OpenAIRE

González, Roberto; Hernández de la Iglesia, Daniel; de la Prieta Pintado, Fernando; Gil González, Ana Belén

2017-01-01

Cloud computing is revolutionizing the services provided through the Internet, and is continually adapting itself in order to maintain the quality of its services. This study presents the platform +Cloud, which proposes a cloud environment for storing information and files by following the cloud paradigm. This study also presents Warehouse 3.0, a cloud-based application that has been developed to validate the services provided by +Cloud.

The sensitivities of in cloud and cloud top phase distributions to primary ice formation in ICON-LEM

Science.gov (United States)

Beydoun, H.; Karrer, M.; Tonttila, J.; Hoose, C.

2017-12-01

Mixed phase clouds remain a leading source of uncertainty in our attempt to quantify cloud-climate and aerosol-cloud climate interactions. Nevertheless, recent advances in parametrizing the primary ice formation process, high resolution cloud modelling, and retrievals of cloud phase distributions from satellite data offer an excellent opportunity to conduct closure studies on the sensitivity of the cloud phase to microphysical and dynamical processes. Particularly, the reliability of satellite data to resolve the phase at the top of the cloud provides a promising benchmark to compare model output to. We run large eddy simulations with the new ICOsahedral Non-hydrostatic atmosphere model (ICON) to place bounds on the sensitivity of in cloud and cloud top phase to the primary ice formation process. State of the art primary ice formation parametrizations in the form of the cumulative ice active site density ns are implemented in idealized deep convective cloud simulations. We exploit the ability of ICON-LEM to switch between a two moment microphysics scheme and the newly developed Predicted Particle Properties (P3) scheme by running our simulations in both configurations for comparison. To quantify the sensitivity of cloud phase to primary ice formation, cloud ice content is evaluated against order of magnitude changes in ns at variable convective strengths. Furthermore, we assess differences between in cloud and cloud top phase distributions as well as the potential impact of updraft velocity on the suppression of the Wegener-Bergeron-Findeisen process. The study aims to evaluate our practical understanding of primary ice formation in the context of predicting the structure and evolution of mixed phase clouds.

12MAP: Cloud Disaster Recovery Based on Image-Instance Mapping

OpenAIRE

Nadgowda , Shripad; Jayachandran , Praveen; Verma , Akshat

2013-01-01

Part 2: Cloud Computing; International audience; Virtual machines (VMs) in a cloud use standardized ‘golden master’ images, standard software catalog and management tools. This facilitates quick provisioning of VMs and helps reduce the cost of managing the cloud by reducing the need for specialized software skills. However, knowledge of this similarity is lost post-provisioning, as VMs could experience different changes and may drift away from one another. In this work, we propose the 12MAP s...

Microphysical processing of aerosol particles in orographic clouds

Science.gov (United States)

Pousse-Nottelmann, S.; Zubler, E. M.; Lohmann, U.

2015-08-01

An explicit and detailed treatment of cloud-borne particles allowing for the consideration of aerosol cycling in clouds has been implemented into COSMO-Model, the regional weather forecast and climate model of the Consortium for Small-scale Modeling (COSMO). The effects of aerosol scavenging, cloud microphysical processing and regeneration upon cloud evaporation on the aerosol population and on subsequent cloud formation are investigated. For this, two-dimensional idealized simulations of moist flow over two bell-shaped mountains were carried out varying the treatment of aerosol scavenging and regeneration processes for a warm-phase and a mixed-phase orographic cloud. The results allowed us to identify different aerosol cycling mechanisms. In the simulated non-precipitating warm-phase cloud, aerosol mass is incorporated into cloud droplets by activation scavenging and released back to the atmosphere upon cloud droplet evaporation. In the mixed-phase cloud, a first cycle comprises cloud droplet activation and evaporation via the Wegener-Bergeron-Findeisen (WBF) process. A second cycle includes below-cloud scavenging by precipitating snow particles and snow sublimation and is connected to the first cycle via the riming process which transfers aerosol mass from cloud droplets to snowflakes. In the simulated mixed-phase cloud, only a negligible part of the total aerosol mass is incorporated into ice crystals. Sedimenting snowflakes reaching the surface remove aerosol mass from the atmosphere. The results show that aerosol processing and regeneration lead to a vertical redistribution of aerosol mass and number. Thereby, the processes impact the total aerosol number and mass and additionally alter the shape of the aerosol size distributions by enhancing the internally mixed/soluble Aitken and accumulation mode and generating coarse-mode particles. Concerning subsequent cloud formation at the second mountain, accounting for aerosol processing and regeneration increases

Cloud computing for protein-ligand binding site comparison.

Science.gov (United States)

Hung, Che-Lun; Hua, Guan-Jie

2013-01-01

The proteome-wide analysis of protein-ligand binding sites and their interactions with ligands is important in structure-based drug design and in understanding ligand cross reactivity and toxicity. The well-known and commonly used software, SMAP, has been designed for 3D ligand binding site comparison and similarity searching of a structural proteome. SMAP can also predict drug side effects and reassign existing drugs to new indications. However, the computing scale of SMAP is limited. We have developed a high availability, high performance system that expands the comparison scale of SMAP. This cloud computing service, called Cloud-PLBS, combines the SMAP and Hadoop frameworks and is deployed on a virtual cloud computing platform. To handle the vast amount of experimental data on protein-ligand binding site pairs, Cloud-PLBS exploits the MapReduce paradigm as a management and parallelizing tool. Cloud-PLBS provides a web portal and scalability through which biologists can address a wide range of computer-intensive questions in biology and drug discovery.

Structure of molecules and internal rotation

CERN Document Server

Mizushima, San-Ichiro

1954-01-01

Structure of Molecules and Internal Rotation reviews early studies on dihalogenoethanes. This book is organized into two parts encompassing 8 chapters that evaluate the Raman effect in ethane derivatives, the energy difference between rotational isomers, and the infrared absorption of ethane derivatives. Some of the topics covered in the book are the potential barrier to internal rotation; nature of the hindering potential; entropy difference between the rotational isomers; internal rotation in butane, pentane, and hexane; and internal rotation in long chain n-paraffins. Other chapters deal wi

Point Cloud Management Through the Realization of the Intelligent Cloud Viewer Software

Science.gov (United States)

Costantino, D.; Angelini, M. G.; Settembrini, F.

2017-05-01

The paper presents a software dedicated to the elaboration of point clouds, called Intelligent Cloud Viewer (ICV), made in-house by AESEI software (Spin-Off of Politecnico di Bari), allowing to view point cloud of several tens of millions of points, also on of "no" very high performance systems. The elaborations are carried out on the whole point cloud and managed by means of the display only part of it in order to speed up rendering. It is designed for 64-bit Windows and is fully written in C ++ and integrates different specialized modules for computer graphics (Open Inventor by SGI, Silicon Graphics Inc), maths (BLAS, EIGEN), computational geometry (CGAL, Computational Geometry Algorithms Library), registration and advanced algorithms for point clouds (PCL, Point Cloud Library), advanced data structures (BOOST, Basic Object Oriented Supporting Tools), etc. ICV incorporates a number of features such as, for example, cropping, transformation and georeferencing, matching, registration, decimation, sections, distances calculation between clouds, etc. It has been tested on photographic and TLS (Terrestrial Laser Scanner) data, obtaining satisfactory results. The potentialities of the software have been tested by carrying out the photogrammetric survey of the Castel del Monte which was already available in previous laser scanner survey made from the ground by the same authors. For the aerophotogrammetric survey has been adopted a flight height of approximately 1000ft AGL (Above Ground Level) and, overall, have been acquired over 800 photos in just over 15 minutes, with a covering not less than 80%, the planned speed of about 90 knots.

POINT CLOUD MANAGEMENT THROUGH THE REALIZATION OF THE INTELLIGENT CLOUD VIEWER SOFTWARE

Directory of Open Access Journals (Sweden)

D. Costantino

2017-05-01

Full Text Available The paper presents a software dedicated to the elaboration of point clouds, called Intelligent Cloud Viewer (ICV, made in-house by AESEI software (Spin-Off of Politecnico di Bari, allowing to view point cloud of several tens of millions of points, also on of “no” very high performance systems. The elaborations are carried out on the whole point cloud and managed by means of the display only part of it in order to speed up rendering. It is designed for 64-bit Windows and is fully written in C ++ and integrates different specialized modules for computer graphics (Open Inventor by SGI, Silicon Graphics Inc, maths (BLAS, EIGEN, computational geometry (CGAL, Computational Geometry Algorithms Library, registration and advanced algorithms for point clouds (PCL, Point Cloud Library, advanced data structures (BOOST, Basic Object Oriented Supporting Tools, etc. ICV incorporates a number of features such as, for example, cropping, transformation and georeferencing, matching, registration, decimation, sections, distances calculation between clouds, etc. It has been tested on photographic and TLS (Terrestrial Laser Scanner data, obtaining satisfactory results. The potentialities of the software have been tested by carrying out the photogrammetric survey of the Castel del Monte which was already available in previous laser scanner survey made from the ground by the same authors. For the aerophotogrammetric survey has been adopted a flight height of approximately 1000ft AGL (Above Ground Level and, overall, have been acquired over 800 photos in just over 15 minutes, with a covering not less than 80%, the planned speed of about 90 knots.

Structure, richness and composition of arboreal plants in a cloud thinning forest of Tolima (Colombia)

International Nuclear Information System (INIS)

Campo Kurmen, Juan Manuel

2010-01-01

Structure, richness, and floristic composition of the woody elements of the selective logging forest of the Vereda Dantas, (Ibague, Tolima, Colombia), where studied in a 0.1 ha plot sampled for all individuals ≥2.5 cm dbh. the forest is characterized by scarcity of lianas and hemiepiphytic, absence of typical families of the Colombian cloud forests between 2000 and 2500 m (Araceae, Ericaceae, Myrtaceae, Meliaceae and Aquifoliaceae), and richness increment of the Sabiaceae and Euphorbiaceae. Compared to others cloud forest from the Colombian Andes and the Neotropic, it has, fewer individuals (237 individuals ≥2.5 cm dbh per 0.1 ha) and more large trees (39.7% of individuals ≥10 cm dbh per 0.1 ha). The forest has a lower woody species richness (75 species ≥2.5 cm dbh per 0.1 ha). Apparently, the effects of selective timber extraction on structure, richness, and floristic composition are decrease floristic richness and density of individuals, decrease of lianas density and richness, and more individuals of secondary species, likes: Hedyosmum goudotianum Slms-Laubach var. goudatianum, Miconia resima Naud, and Palicourea calophlebia Standl.

Cloud residues and interstitial aerosols from non-precipitating clouds over an industrial and urban area in northern China

Science.gov (United States)

Li, Weijun; Li, Peiren; Sun, Guode; Zhou, Shengzhen; Yuan, Qi; Wang, Wenxing

2011-05-01

Most studies of aerosol-cloud interactions have been conducted in remote locations; few have investigated the characterization of cloud condensation nuclei (CCN) over highly polluted urban and industrial areas. The present work, based on samples collected at Mt. Tai, a site in northern China affected by nearby urban and industrial air pollutant emissions, illuminates CCN properties in a polluted atmosphere. High-resolution transmission electron microscopy (TEM) was used to obtain the size, composition, and mixing state of individual cloud residues and interstitial aerosols. Most of the cloud residues displayed distinct rims which were found to consist of soluble organic matter (OM). Nearly all (91.7%) cloud residues were attributed to sulfate-related salts (the remainder was mostly coarse crustal dust particles with nitrate coatings). Half the salt particles were internally mixed with two or more refractory particles (e.g., soot, fly ash, crustal dust, CaSO 4, and OM). A comparison between cloud residues and interstitial particles shows that the former contained more salts and were of larger particle size than the latter. In addition, a somewhat high number scavenging ratio of 0.54 was observed during cloud formation. Therefore, the mixtures of salts with OMs account for most of the cloud-nucleating ability of the entire aerosol population in the polluted air of northern China. We advocate that both size and composition - the two influential, controlling factors for aerosol activation - should be built into all regional climate models of China.

Silicon Photonics Cloud (SiCloud)

DEFF Research Database (Denmark)

DeVore, P. T. S.; Jiang, Y.; Lynch, M.

2015-01-01

Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths.......Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths....

The VMC survey - XXVI. Structure of the Small Magellanic Cloud from RR Lyrae stars

Science.gov (United States)

Muraveva, T.; Subramanian, S.; Clementini, G.; Cioni, M.-R. L.; Palmer, M.; van Loon, J. Th.; Moretti, M. I.; de Grijs, R.; Molinaro, R.; Ripepi, V.; Marconi, M.; Emerson, J.; Ivanov, V. D.

2018-01-01

We present results from the analysis of 2997 fundamental mode RR Lyrae variables located in the Small Magellanic Cloud (SMC). For these objects, near-infrared time series photometry from the VISTA survey of the Magellanic Clouds system (VMC) and visual light curves from the OGLE IV (Optical Gravitational Lensing Experiment IV) survey are available. In this study, the multi-epoch Ks-band VMC photometry was used for the first time to derive intensity-averaged magnitudes of the SMC RR Lyrae stars. We determined individual distances to the RR Lyrae stars from the near-infrared period-absolute magnitude-metallicity (PM_{K_s}Z) relation, which has some advantages in comparison with the visual absolute magnitude-metallicity (MV-[Fe/H]) relation, such as a smaller dependence of the luminosity on interstellar extinction, evolutionary effects and metallicity. The distances we have obtained were used to study the three-dimensional structure of the SMC. The distribution of the SMC RR Lyrae stars is found to be ellipsoidal. The actual line-of-sight depth of the SMC is in the range 1-10 kpc, with an average depth of 4.3 ± 1.0 kpc. We found that RR Lyrae stars in the eastern part of the SMC are affected by interactions of the Magellanic Clouds. However, we do not see a clear bimodality observed for red clump stars, in the distribution of RR Lyrae stars.

Closing the Skill Gap of Cloud CRM Application Services in Cloud Computing for Evaluating Big Data Solutions

Directory of Open Access Journals (Sweden)

You-Shyang Chen

2016-12-01

Full Text Available Information systems (IS continually motivate various improvements in the state-of-the-art of issues and solutions for advanced geo-information technologies in cloud computing. Reducing IS project risks and improving organizational performance has become an important issue. This study proposes a research framework, constructed from the Stimulus-Organism-Response (S-O-R framework, in order to address the issues comprising the stimulus of project risk, the organism of project management, and the response of organizational performance for cloud service solutions. Cloud customer relationship management (cloud CRM experts, based on cloud computing, with many years of project management experience, were selected for the interview sample in this study. Decision Making Trial and Evaluation Laboratory–based analytical network process (DEMATEL based-ANP, DANP is a multiple-criteria decision-making (MCDM analysis tool that does not have prior assumptions and it was used to experience the dynamic relationships among project risk, project management, and organizational performance. The study results include three directions: (a Improving the internal business process performance can improve the efficiency of cloud CRM project processes and activities; (b The emphasis on financial performance management can reduce the cost of a cloud CRM project so that the project can be completed within the approved budget; (c Meeting user needs can improve user risk and reduce negative cloud CRM user experience. The scientific value of this study can be extended in order to study different projects, through research methods and frameworks, in order to explore project risk management and corporate performance improvements.

Microphysical processing of aerosol particles in orographic clouds

Directory of Open Access Journals (Sweden)

S. Pousse-Nottelmann

2015-08-01

aerosol cycling in clouds has been implemented into COSMO-Model, the regional weather forecast and climate model of the Consortium for Small-scale Modeling (COSMO. The effects of aerosol scavenging, cloud microphysical processing and regeneration upon cloud evaporation on the aerosol population and on subsequent cloud formation are investigated. For this, two-dimensional idealized simulations of moist flow over two bell-shaped mountains were carried out varying the treatment of aerosol scavenging and regeneration processes for a warm-phase and a mixed-phase orographic cloud. The results allowed us to identify different aerosol cycling mechanisms. In the simulated non-precipitating warm-phase cloud, aerosol mass is incorporated into cloud droplets by activation scavenging and released back to the atmosphere upon cloud droplet evaporation. In the mixed-phase cloud, a first cycle comprises cloud droplet activation and evaporation via the Wegener–Bergeron–Findeisen (WBF process. A second cycle includes below-cloud scavenging by precipitating snow particles and snow sublimation and is connected to the first cycle via the riming process which transfers aerosol mass from cloud droplets to snowflakes. In the simulated mixed-phase cloud, only a negligible part of the total aerosol mass is incorporated into ice crystals. Sedimenting snowflakes reaching the surface remove aerosol mass from the atmosphere. The results show that aerosol processing and regeneration lead to a vertical redistribution of aerosol mass and number. Thereby, the processes impact the total aerosol number and mass and additionally alter the shape of the aerosol size distributions by enhancing the internally mixed/soluble Aitken and accumulation mode and generating coarse-mode particles. Concerning subsequent cloud formation at the second mountain, accounting for aerosol processing and regeneration increases the cloud droplet number concentration with possible implications for the ice crystal number

Using Amazon's Elastic Compute Cloud to dynamically scale CMS computational resources

International Nuclear Information System (INIS)

Evans, D; Fisk, I; Holzman, B; Pordes, R; Tiradani, A; Melo, A; Sheldon, P; Metson, S

2011-01-01

Large international scientific collaborations such as the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider have traditionally addressed their data reduction and analysis needs by building and maintaining dedicated computational infrastructure. Emerging cloud computing services such as Amazon's Elastic Compute Cloud (EC2) offer short-term CPU and storage resources with costs based on usage. These services allow experiments to purchase computing resources as needed, without significant prior planning and without long term investments in facilities and their management. We have demonstrated that services such as EC2 can successfully be integrated into the production-computing model of CMS, and find that they work very well as worker nodes. The cost-structure and transient nature of EC2 services makes them inappropriate for some CMS production services and functions. We also found that the resources are not truely 'on-demand' as limits and caps on usage are imposed. Our trial workflows allow us to make a cost comparison between EC2 resources and dedicated CMS resources at a University, and conclude that it is most cost effective to purchase dedicated resources for the 'base-line' needs of experiments such as CMS. However, if the ability to use cloud computing resources is built into an experiment's software framework before demand requires their use, cloud computing resources make sense for bursting during times when spikes in usage are required.

Cloud Processed CCN Suppress Stratus Cloud Drizzle

Science.gov (United States)

Hudson, J. G.; Noble, S. R., Jr.

2017-12-01

Conversion of sulfur dioxide to sulfate within cloud droplets increases the sizes and decreases the critical supersaturation, Sc, of cloud residual particles that had nucleated the droplets. Since other particles remain at the same sizes and Sc a size and Sc gap is often observed. Hudson et al. (2015) showed higher cloud droplet concentrations (Nc) in stratus clouds associated with bimodal high-resolution CCN spectra from the DRI CCN spectrometer compared to clouds associated with unimodal CCN spectra (not cloud processed). Here we show that CCN spectral shape (bimodal or unimodal) affects all aspects of stratus cloud microphysics and drizzle. Panel A shows mean differential cloud droplet spectra that have been divided according to traditional slopes, k, of the 131 measured CCN spectra in the Marine Stratus/Stratocumulus Experiment (MASE) off the Central California coast. K is generally high within the supersaturation, S, range of stratus clouds (< 0.5%). Because cloud processing decreases Sc of some particles, it reduces k. Panel A shows higher concentrations of small cloud droplets apparently grown on lower k CCN than clouds grown on higher k CCN. At small droplet sizes the concentrations follow the k order of the legend, black, red, green, blue (lowest to highest k). Above 13 µm diameter the lines cross and the hierarchy reverses so that blue (highest k) has the highest concentrations followed by green, red and black (lowest k). This reversed hierarchy continues into the drizzle size range (panel B) where the most drizzle drops, Nd, are in clouds grown on the least cloud-processed CCN (blue), while clouds grown on the most processed CCN (black) have the lowest Nd. Suppression of stratus cloud drizzle by cloud processing is an additional 2nd indirect aerosol effect (IAE) that along with the enhancement of 1st IAE by higher Nc (panel A) are above and beyond original IAE. However, further similar analysis is needed in other cloud regimes to determine if MASE was

Circumstellar Disks and Outflows in Turbulent Molecular Cloud Cores: Possible Formation Mechanism for Misaligned Systems

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Tomoaki [Faculty of Sustainability Studies, Hosei University, Fujimi, Chiyoda-ku, Tokyo 102-8160 (Japan); Machida, Masahiro N. [Department of Earth and Planetary Sciences, Kyushu University, Fukuoka 812-8581 (Japan); Inutsuka, Shu-ichiro, E-mail: matsu@hosei.ac.jp [Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)

2017-04-10

We investigate the formation of circumstellar disks and outflows subsequent to the collapse of molecular cloud cores with the magnetic field and turbulence. Numerical simulations are performed by using an adaptive mesh refinement to follow the evolution up to ∼1000 years after the formation of a protostar. In the simulations, circumstellar disks are formed around the protostars; those in magnetized models are considerably smaller than those in nonmagnetized models, but their size increases with time. The models with stronger magnetic fields tend to produce smaller disks. During evolution in the magnetized models, the mass ratios of a disk to a protostar is approximately constant at ∼1%–10%. The circumstellar disks are aligned according to their angular momentum, and the outflows accelerate along the magnetic field on the 10–100 au scale; this produces a disk that is misaligned with the outflow. The outflows are classified into two types: a magnetocentrifugal wind and a spiral flow. In the latter, because of the geometry, the axis of rotation is misaligned with the magnetic field. The magnetic field has an internal structure in the cloud cores, which also causes misalignment between the outflows and the magnetic field on the scale of the cloud core. The distribution of the angular momentum vectors in a core also has a non-monotonic internal structure. This should create a time-dependent accretion of angular momenta onto the circumstellar disk. Therefore, the circumstellar disks are expected to change their orientation as well as their sizes in the long-term evolutions.

Radiative effect differences between multi-layered and single-layer clouds derived from CERES, CALIPSO, and CloudSat data

International Nuclear Information System (INIS)

Li Jiming; Yi Yuhong; Minnis, Patrick; Huang Jianping; Yan Hongru; Ma Yuejie; Wang Wencai; Kirk Ayers, J.

2011-01-01

Clouds alter general circulation through modification of the radiative heating profile within the atmosphere. Their effects are complex and depend on height, vertical structure, and phase. The instantaneous cloud radiative effect (CRE) induced by multi-layered (ML) and single-layer (SL) clouds is estimated by analyzing data collected by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), CloudSat, and Clouds and Earth's Radiation Energy Budget System (CERES) missions from March 2007 through February 2008. The CRE differences between ML and SL clouds at the top of the atmosphere (TOA) and at the surface were also examined. The zonal mean shortwave (SW) CRE differences between the ML and SL clouds at the TOA and surface were positive at most latitudes, peaking at 120 W m -2 in the tropics and dropping to -30 W m -2 at higher latitudes. This indicated that the ML clouds usually reflected less sunlight at the TOA and transmitted more to the surface than the SL clouds, due to their higher cloud top heights. The zonal mean longwave (LW) CRE differences between ML and SL clouds at the TOA and surface were relatively small, ranging from -30 to 30 W m -2 . This showed that the ML clouds only increased the amount of thermal radiation at the TOA relative to the SL clouds in the tropics, decreasing it elsewhere. In other words, ML clouds tended to cool the atmosphere in the tropics and warm it elsewhere when compared to SL clouds. The zonal mean net CRE differences were positive at most latitudes and dominated by the SW CRE differences.

Submm-Wave Radiometry for Cloud/Humidity/Precipitation Sciences

Science.gov (United States)

Wu, Dong L.

2011-01-01

Although active sensors can provide cloud profiles at good vertical resolution, clouds are often coupled with dynamics to form fast and organized structures. Lack of understanding of these organized systems leads to great challenge for numerical models. The deficiency is partly reflected, for example, in poorly modeled intraseasonal variations (e.g., MJD). Remote sensing clouds in the middle and upper troposphere has been challenging from space. Vis/IR sensors are sensitive to the topmost cloud layers whereas low-frequency MW techniques are sensitivity to liquid and precipitation at the bottom of cloud layers. The middle-level clouds, mostly in the ice phase, require a sensor that has moderate penetration and sensitivity to cloud scattering, in order to measure cloud water content. Sensors at submm wavelengths provide promising sensitivity and coverage with the spatial resolution needed to measure cloud water content floating in the upper air. In addition, submm-wave sensors are able to provide better measurements of upper-tropospheric humidity than traditional microwave instruments.

Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

Science.gov (United States)

Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

2014-11-01

We have investigated the cloud top structure of Venus by analyzing ground-based images taken at the mid-infrared wavelengths of 8.66 μm and 11.34 μm. Venus at a solar phase angle of ∼90°, with the morning terminator in view, was observed by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope, during the period October 25-29, 2007. The disk-averaged brightness temperatures for the observation period are ∼230 K and ∼238 K at 8.66 μm and 11.34 μm, respectively. The obtained images with good signal-to-noise ratio and with high spatial resolution (∼200 km at the sub-observer point) provide several important findings. First, we present observational evidence, for the first time, of the possibility that the westward rotation of the polar features (the hot polar spots and the surrounding cold collars) is synchronized between the northern and southern hemispheres. Second, after high-pass filtering, the images reveal that streaks and mottled and patchy patterns are distributed over the entire disk, with typical amplitudes of ∼0.5 K, and vary from day to day. The detected features, some of which are similar to those seen in past UV images, result from inhomogeneities of both the temperature and the cloud top altitude. Third, the equatorial center-to-limb variations of brightness temperatures have a systematic day-night asymmetry, except those on October 25, that the dayside brightness temperatures are higher than the nightside brightness temperatures by 0-4 K under the same viewing geometry. Such asymmetry would be caused by the propagation of the migrating semidiurnal tide. Finally, by applying the lapse rates deduced from previous studies, we demonstrate that the equatorial center-to-limb curves in the two spectral channels give access to two parameters: the cloud scale height H and the cloud top altitude zc. The acceptable models for data on October 25 are obtained at H = 2.4-4.3 km and zc = 66-69 km; this supports

Fractal properties and denoising of lidar signals from cirrus clouds

NARCIS (Netherlands)

Heuvel, J.C. van den; Driesenaar, M.L.; Lerou, R.J.L.

2000-01-01

Airborne lidar signals of cirrus clouds are analyzed to determine the cloud structure. Climate modeling and numerical weather prediction benefit from accurate modeling of cirrus clouds. Airborne lidar measurements of the European Lidar in Space Technology Experiment (ELITE) campaign were analyzed by

ON THE STAR FORMATION RATES IN MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Lada, Charles J.; Lombardi, Marco; Alves, Joao F.

2010-01-01

In this paper, we investigate the level of star formation activity within nearby molecular clouds. We employ a uniform set of infrared extinction maps to provide accurate assessments of cloud mass and structure and compare these with inventories of young stellar objects within the clouds. We present evidence indicating that both the yield and rate of star formation can vary considerably in local clouds, independent of their mass and size. We find that the surface density structure of such clouds appears to be important in controlling both these factors. In particular, we find that the star formation rate (SFR) in molecular clouds is linearly proportional to the cloud mass (M 0.8 ) above an extinction threshold of A K ∼ 0.8 mag, corresponding to a gas surface density threshold of Σ gas ∼ 116 M sun pc 2 . We argue that this surface density threshold corresponds to a gas volume density threshold which we estimate to be n(H 2 ) ∼ 10 4 cm -3 . Specifically, we find SFR (M sun yr -1 ) = 4.6 ± 2.6 x 10 -8 M 0.8 (M sun ) for the clouds in our sample. This relation between the rate of star formation and the amount of dense gas in molecular clouds appears to be in excellent agreement with previous observations of both galactic and extragalactic star-forming activity. It is likely the underlying physical relationship or empirical law that most directly connects star formation activity with interstellar gas over many spatial scales within and between individual galaxies. These results suggest that the key to obtaining a predictive understanding of the SFRs in molecular clouds and galaxies is to understand those physical factors which give rise to the dense components of these clouds.

Cloud vertical profiles derived from CALIPSO and CloudSat and a comparison with MODIS derived clouds

Science.gov (United States)

Kato, S.; Sun-Mack, S.; Miller, W. F.; Rose, F. G.; Minnis, P.; Wielicki, B. A.; Winker, D. M.; Stephens, G. L.; Charlock, T. P.; Collins, W. D.; Loeb, N. G.; Stackhouse, P. W.; Xu, K.

2008-05-01

CALIPSO and CloudSat from the a-train provide detailed information of vertical distribution of clouds and aerosols. The vertical distribution of cloud occurrence is derived from one month of CALIPSO and CloudSat data as a part of the effort of merging CALIPSO, CloudSat and MODIS with CERES data. This newly derived cloud profile is compared with the distribution of cloud top height derived from MODIS on Aqua from cloud algorithms used in the CERES project. The cloud base from MODIS is also estimated using an empirical formula based on the cloud top height and optical thickness, which is used in CERES processes. While MODIS detects mid and low level clouds over the Arctic in April fairly well when they are the topmost cloud layer, it underestimates high- level clouds. In addition, because the CERES-MODIS cloud algorithm is not able to detect multi-layer clouds and the empirical formula significantly underestimates the depth of high clouds, the occurrence of mid and low-level clouds is underestimated. This comparison does not consider sensitivity difference to thin clouds but we will impose an optical thickness threshold to CALIPSO derived clouds for a further comparison. The effect of such differences in the cloud profile to flux computations will also be discussed. In addition, the effect of cloud cover to the top-of-atmosphere flux over the Arctic using CERES SSF and FLASHFLUX products will be discussed.

A Cloud Top Pressure Algorithm for DSCOVR-EPIC

Science.gov (United States)

Min, Q.; Morgan, E. C.; Yang, Y.; Marshak, A.; Davis, A. B.

2017-12-01

The Earth Polychromatic Imaging Camera (EPIC) sensor on the Deep Space Climate Observatory (DSCOVR) satellite presents unique opportunities to derive cloud properties of the entire daytime Earth. In particular, the Oxygen A- and B-band and corresponding reference channels provide cloud top pressure information. In order to address the in-cloud penetration depth issue—and ensuing retrieval bias—a comprehensive sensitivity study has been conducted to simulate satellite-observed radiances for a wide variety of cloud structures and optical properties. Based on this sensitivity study, a cloud top pressure algorithm for DSCOVR-EPIC has been developed. Further, the algorithm has been applied to EPIC measurements.

The simulation of molecular clouds formation in the Milky Way

Science.gov (United States)

Khoperskov, S. A.; Vasiliev, E. O.; Sobolev, A. M.; Khoperskov, A. V.

2013-01-01

Using 3D hydrodynamic calculations we simulate formation of molecular clouds in the Galaxy. The simulations take into account molecular hydrogen chemical kinetics, cooling and heating processes. Comprehensive gravitational potential accounts for contributions from the stellar bulge, two- and four-armed spiral structure, stellar disc, dark halo and takes into account self-gravitation of the gaseous component. Gas clouds in our model form in the spiral arms due to shear and wiggle instabilities and turn into molecular clouds after t ≳ 100 Myr. At the times t ˜ 100-300 Myr the clouds form hierarchical structures and agglomerations with the sizes of 100 pc and greater. We analyse physical properties of the simulated clouds and find that synthetic statistical distributions like mass spectrum, `mass-size' relation and velocity dispersion are close to those observed in the Galaxy. The synthetic l-v (galactic longitude-radial velocity) diagram of the simulated molecular gas distribution resembles observed one and displays a structure with appearance similar to molecular ring of the Galaxy. Existence of this structure in our modelling can be explained by superposition of emission from the galactic bar and the spiral arms at ˜3-4 kpc.

Scanning Cloud Radar Observations at Azores: Preliminary 3D Cloud Products

Energy Technology Data Exchange (ETDEWEB)

Kollias, P.; Johnson, K.; Jo, I.; Tatarevic, A.; Giangrande, S.; Widener, K.; Bharadwaj, N.; Mead, J.

2010-03-15

The deployment of the Scanning W-Band ARM Cloud Radar (SWACR) during the AMF campaign at Azores signals the first deployment of an ARM Facility-owned scanning cloud radar and offers a prelude for the type of 3D cloud observations that ARM will have the capability to provide at all the ARM Climate Research Facility sites by the end of 2010. The primary objective of the deployment of Scanning ARM Cloud Radars (SACRs) at the ARM Facility sites is to map continuously (operationally) the 3D structure of clouds and shallow precipitation and to provide 3D microphysical and dynamical retrievals for cloud life cycle and cloud-scale process studies. This is a challenging task, never attempted before, and requires significant research and development efforts in order to understand the radar's capabilities and limitations. At the same time, we need to look beyond the radar meteorology aspects of the challenge and ensure that the hardware and software capabilities of the new systems are utilized for the development of 3D data products that address the scientific needs of the new Atmospheric System Research (ASR) program. The SWACR observations at Azores provide a first look at such observations and the challenges associated with their analysis and interpretation. The set of scan strategies applied during the SWACR deployment and their merit is discussed. The scan strategies were adjusted for the detection of marine stratocumulus and shallow cumulus that were frequently observed at the Azores deployment. Quality control procedures for the radar reflectivity and Doppler products are presented. Finally, preliminary 3D-Active Remote Sensing of Cloud Locations (3D-ARSCL) products on a regular grid will be presented, and the challenges associated with their development discussed. In addition to data from the Azores deployment, limited data from the follow-up deployment of the SWACR at the ARM SGP site will be presented. This effort provides a blueprint for the effort required

Challenges for Cloud Modeling in the Context of Aerosol–Cloud–Precipitation Interactions

Energy Technology Data Exchange (ETDEWEB)

Lebo, Zachary J. [Department of Atmospheric Science, University of Wyoming, Laramie, Wyoming; Shipway, Ben J. [Met Office, Exeter, United Kingdom; Fan, Jiwen [Pacific Northwest National Laboratory, Richland, Washington; Geresdi, Istvan [Faculty of Science, University of Pécs, Pécs, Hungary; Hill, Adrian [Met Office, Exeter, United Kingdom; Miltenberger, Annette [School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Morrison, Hugh [Mesoscale and Microscale Meteorology Laboratory, National Center for Atmospheric Research, Boulder, Colorado; Rosenberg, Phil [School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Varble, Adam [Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah; Xue, Lulin [Research Applications Laboratory, National Center for Atmospheric Research, Boulder, Colorado

2017-08-01

The International Cloud Modeling Workshop (CMW) has been a longstanding tradition in the cloud microphysics modeling community and is typically held the week prior to the International Conference on Clouds and Precipitation (ICCP). For the Ninth CMW, more than 40 participants from 10 countries convened at the Met Office in Exeter, United Kingdom. The workshop included 4 detailed case studies (described in more detail below) rooted in recent field campaigns. The overarching objective of these cases was to utilize new observations to better understand inter-model differences and model deficiencies, explore new modeling techniques, and gain physical insight into the behavior of clouds. As was the case at the Eighth CMW, there was a general theme of understanding the role of aerosol impacts in the context of cloud-precipitation interactions. However, an additional objective was the focal point of several cases at the most recent workshop: microphysical-dynamical interactions. Many of the cases focused less on idealized small-domain simulations (as was the general focus of previous workshops) and more on large-scale nested configurations examining effects at various scales.

CubeSat Constellation Cloud Winds(C3Winds) A New Wind Observing System to Study Mesoscale Cloud Dynamics and Processes

Science.gov (United States)

Wu, D. L.; Kelly, M.A.; Yee, J.-H.; Boldt, J.; Demajistre, R.; Reynolds, E. L.; Tripoli, G. J.; Oman, L. D.; Prive, N.; Heidinger, A. K.;

Characteristics of bacterial community in cloud water at Mt Tai: similarity and disparity under polluted and non-polluted cloud episodes

Science.gov (United States)

Wei, Min; Xu, Caihong; Chen, Jianmin; Zhu, Chao; Li, Jiarong; Lv, Ganglin

2017-04-01

Bacteria are widely distributed in atmospheric aerosols and are indispensable components of clouds, playing an important role in the atmospheric hydrological cycle. However, limited information is available about the bacterial community structure and function, especially for the increasing air pollution in the North China Plain. Here, we present a comprehensive characterization of bacterial community composition, function, variation, and environmental influence for cloud water collected at Mt Tai from 24 July to 23 August 2014. Using Miseq 16S rRNA gene sequencing, the highly diverse bacterial community in cloud water and the predominant phyla of Proteobacteria, Bacteroidetes, Cyanobacteria, and Firmicutes were investigated. Bacteria that survive at low temperature, radiation, and poor nutrient conditions were found in cloud water, suggesting adaption to an extreme environment. The bacterial gene functions predicted from the 16S rRNA gene using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) suggested that the pathways related to metabolism and disease infections were significantly correlated with the predominant genera. The abundant genera Acinetobacter, Stenotrophomonas, Pseudomonas, and Empedobacter originated from a wide range of habitats including cloud condensation nuclei and ice nuclei active species, opportunistic pathogens, and functional species, demonstrating the importance of ecology and health in cloud water. Cluster analysis including hierarchical cluster (Hcluster) and principal coordinate analysis (PCoA) indicated a significant disparity between polluted and non-polluted samples. Linear discriminant analysis effect size (LEfSe) demonstrated that potential pathogens were enriched in the polluted cloud samples, whereas the diverse ecological function groups were significant in the non-polluted samples. Discrepant community structure determined by redundancy analysis (RDA) indicated that the major ions in

A cloud climatology of the Southern Great Plains ARM CART

Energy Technology Data Exchange (ETDEWEB)

Lazarus, S.M.; Krueger, S.K.; Mace, G.G.

2000-05-15

Cloud amount statistics from three different sources were processed and compared. Surface observations from a National Centers for Environmental Prediction dataset were used. The data (Edited Cloud Report; ECR) consist of synoptic weather reports that have been edited to facilitate cloud analysis. Two stations near the Southern Great Plains (SGP) Cloud and Radiation Test Bed (CART) in north-central Oklahoma (Oklahoma City, Oklahoma and Wichita, Kansas) were selected. The ECR data span a 10-yr period from December 1981 to November 1991. The International Satellite Cloud Climatology Project (ISCCP) provided cloud amounts over the SGP CART for an 8-yr period (1983--91). Cloud amounts were also obtained from Micro Pulse Lidar (MPL) and Belfort Ceilometer (BLC) cloud-base height measurements made at the SGP CART over a 1-yr period. The annual and diurnal cycles of cloud amount as a function of cloud height and type were analyzed. The three datasets closely agree for total cloud amount. Good agreement was found in the ECR and MPL-BLC monthly low cloud amounts. With the exception of summer and midday in other seasons, the ISCCP low cloud amount estimates are generally 5%--10% less than the others. The ECR high cloud amount estimates are typically 10%--15% greater than those obtained from either the ISCCP or MPL-BLC datasets. The observed diurnal variations of altocumulus support the authors' model results of radiatively induced circulations.

The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model

Directory of Open Access Journals (Sweden)

A. Teller

2006-01-01

Full Text Available Numerical experiments were carried out using the Tel-Aviv University 2-D cloud model to investigate the effects of increased concentrations of Cloud Condensation Nuclei (CCN, giant CCN (GCCN and Ice Nuclei (IN on the development of precipitation and cloud structure in mixed-phase sub-tropical convective clouds. In order to differentiate between the contribution of the aerosols and the meteorology, all simulations were conducted with the same meteorological conditions. The results show that under the same meteorological conditions, polluted clouds (with high CCN concentrations produce less precipitation than clean clouds (with low CCN concentrations, the initiation of precipitation is delayed and the lifetimes of the clouds are longer. GCCN enhance the total precipitation on the ground in polluted clouds but they have no noticeable effect on cleaner clouds. The increased rainfall due to GCCN is mainly a result of the increased graupel mass in the cloud, but it only partially offsets the decrease in rainfall due to pollution (increased CCN. The addition of more effective IN, such as mineral dust particles, reduces the total amount of precipitation on the ground. This reduction is more pronounced in clean clouds than in polluted ones. Polluted clouds reach higher altitudes and are wider than clean clouds and both produce wider clouds (anvils when more IN are introduced. Since under the same vertical sounding the polluted clouds produce less rain, more water vapor is left aloft after the rain stops. In our simulations about 3.5 times more water evaporates after the rain stops from the polluted cloud as compared to the clean cloud. The implication is that much more water vapor is transported from lower levels to the mid troposphere under polluted conditions, something that should be considered in climate models.

Similar complex kinematics within two massive, filamentary infrared dark clouds

Science.gov (United States)

Barnes, A. T.; Henshaw, J. D.; Caselli, P.; Jiménez-Serra, I.; Tan, J. C.; Fontani, F.; Pon, A.; Ragan, S.

2018-04-01

Infrared dark clouds (IRDCs) are thought to be potential hosts of the elusive early phases of high-mass star formation. Here, we conduct an in-depth kinematic analysis of one such IRDC, G034.43+00.24 (Cloud F), using high sensitivity and high spectral resolution IRAM-30m N2H+ (1-0) and C18O (1-0) observations. To disentangle the complex velocity structure within this cloud, we use Gaussian decomposition and hierarchical clustering algorithms. We find that four distinct coherent velocity components are present within Cloud F. The properties of these components are compared to those found in a similar IRDC, G035.39-00.33 (Cloud H). We find that the components in both clouds have high densities (inferred by their identification in N2H+), trans-to-supersonic non-thermal velocity dispersions with Mach numbers of ˜1.5-4, a separation in velocity of ˜3 km s-1, and a mean red-shift of ˜0.3 km s-1 between the N2H+ (dense gas) and C18O emission (envelope gas). The latter of these could suggest that these clouds share a common formation scenario. We investigate the kinematics of the larger-scale Cloud F structures, using lower-density-tracing 13CO(1-0) observations. A good correspondence is found between the components identified in the IRAM-30m observations and the most prominent component in the 13CO data. We find that the IRDC Cloud F is only a small part of a much larger structure, which appears to be an inter-arm filament of the Milky Way.

Atlas2 Cloud: a framework for personal genome analysis in the cloud.

Science.gov (United States)

Evani, Uday S; Challis, Danny; Yu, Jin; Jackson, Andrew R; Paithankar, Sameer; Bainbridge, Matthew N; Jakkamsetti, Adinarayana; Pham, Peter; Coarfa, Cristian; Milosavljevic, Aleksandar; Yu, Fuli

2012-01-01

Until recently, sequencing has primarily been carried out in large genome centers which have invested heavily in developing the computational infrastructure that enables genomic sequence analysis. The recent advancements in next generation sequencing (NGS) have led to a wide dissemination of sequencing technologies and data, to highly diverse research groups. It is expected that clinical sequencing will become part of diagnostic routines shortly. However, limited accessibility to computational infrastructure and high quality bioinformatic tools, and the demand for personnel skilled in data analysis and interpretation remains a serious bottleneck. To this end, the cloud computing and Software-as-a-Service (SaaS) technologies can help address these issues. We successfully enabled the Atlas2 Cloud pipeline for personal genome analysis on two different cloud service platforms: a community cloud via the Genboree Workbench, and a commercial cloud via the Amazon Web Services using Software-as-a-Service model. We report a case study of personal genome analysis using our Atlas2 Genboree pipeline. We also outline a detailed cost structure for running Atlas2 Amazon on whole exome capture data, providing cost projections in terms of storage, compute and I/O when running Atlas2 Amazon on a large data set. We find that providing a web interface and an optimized pipeline clearly facilitates usage of cloud computing for personal genome analysis, but for it to be routinely used for large scale projects there needs to be a paradigm shift in the way we develop tools, in standard operating procedures, and in funding mechanisms.

Job Scheduling with Efficient Resource Monitoring in Cloud Datacenter

Directory of Open Access Journals (Sweden)

Shyamala Loganathan

2015-01-01

Full Text Available Cloud computing is an on-demand computing model, which uses virtualization technology to provide cloud resources to users in the form of virtual machines through internet. Being an adaptable technology, cloud computing is an excellent alternative for organizations for forming their own private cloud. Since the resources are limited in these private clouds maximizing the utilization of resources and giving the guaranteed service for the user are the ultimate goal. For that, efficient scheduling is needed. This research reports on an efficient data structure for resource management and resource scheduling technique in a private cloud environment and discusses a cloud model. The proposed scheduling algorithm considers the types of jobs and the resource availability in its scheduling decision. Finally, we conducted simulations using CloudSim and compared our algorithm with other existing methods, like V-MCT and priority scheduling algorithms.

MAGNETICALLY DOMINATED PARALLEL INTERSTELLAR FILAMENTS IN THE INFRARED DARK CLOUD G14.225-0.506

International Nuclear Information System (INIS)

Santos, Fábio P.; Busquet, Gemma; Girart, Josep Miquel; Franco, Gabriel A. P.; Zhang, Qizhou

2016-01-01

The infrared dark cloud G14.225-0.506 (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous studies of dust emission and molecular lines have speculated whether magnetic fields could have played an important role in the formation of such elongated structures, which are hosts to numerous young stellar sources. In this work we have conducted a vast polarimetric survey at optical and near-infrared wavelengths in order to study the morphology of magnetic field lines in IRDC G14.2 through the observation of background stars. The orientation of interstellar polarization, which traces magnetic field lines, is perpendicular to most of the filamentary features within the cloud. Additionally, the larger-scale molecular cloud as a whole exhibits an elongated shape also perpendicular to magnetic fields. Estimates of magnetic field strengths indicate values in the range 320–550 μ G, which allow sub-alfvénic conditions, but do not prevent the gravitational collapse of hub–filament structures, which in general are close to the critical state. These characteristics suggest that magnetic fields played the main role in regulating the collapse from large to small scales, leading to the formation of series of parallel elongated structures. The morphology is also consistent with numerical simulations that show how gravitational instabilities develop when subjected to strong magnetic fields. Finally, the results corroborate the hypothesis that strong support from internal magnetic fields might explain why the cloud seems to be contracting on a timescale 2–3 times longer than what is expected from a free-fall collapse.

MAGNETICALLY DOMINATED PARALLEL INTERSTELLAR FILAMENTS IN THE INFRARED DARK CLOUD G14.225-0.506

Energy Technology Data Exchange (ETDEWEB)

Santos, Fábio P. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Busquet, Gemma; Girart, Josep Miquel [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N E-08193 Bellaterra, Catalunya (Spain); Franco, Gabriel A. P. [Departamento de Física—ICEx—UFMG, Caixa Postal 702, 30.123-970 Belo Horizonte, MG (Brazil); Zhang, Qizhou, E-mail: fabiops@northwestern.edu, E-mail: busquet@ice.cat, E-mail: girart@ice.cat, E-mail: franco@fisica.ufmg.br, E-mail: qzhang@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60, Garden Street, Cambridge, MA 02138 (United States)

2016-12-01

The infrared dark cloud G14.225-0.506 (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous studies of dust emission and molecular lines have speculated whether magnetic fields could have played an important role in the formation of such elongated structures, which are hosts to numerous young stellar sources. In this work we have conducted a vast polarimetric survey at optical and near-infrared wavelengths in order to study the morphology of magnetic field lines in IRDC G14.2 through the observation of background stars. The orientation of interstellar polarization, which traces magnetic field lines, is perpendicular to most of the filamentary features within the cloud. Additionally, the larger-scale molecular cloud as a whole exhibits an elongated shape also perpendicular to magnetic fields. Estimates of magnetic field strengths indicate values in the range 320–550 μ G, which allow sub-alfvénic conditions, but do not prevent the gravitational collapse of hub–filament structures, which in general are close to the critical state. These characteristics suggest that magnetic fields played the main role in regulating the collapse from large to small scales, leading to the formation of series of parallel elongated structures. The morphology is also consistent with numerical simulations that show how gravitational instabilities develop when subjected to strong magnetic fields. Finally, the results corroborate the hypothesis that strong support from internal magnetic fields might explain why the cloud seems to be contracting on a timescale 2–3 times longer than what is expected from a free-fall collapse.

The global atmospheric electric circuit and its effects on cloud microphysics

International Nuclear Information System (INIS)

Tinsley, B A

2008-01-01

This review is an overview of progress in understanding the theory and observation of the global atmospheric electric circuit, with the focus on its dc aspects, and its short and long term variability. The effects of the downward ionosphere-earth current density, J z , on cloud microphysics, with its variability as an explanation for small observed changes in weather and climate, will also be reviewed. The global circuit shows responses to external as well as internal forcing. External forcing arises from changes in the distribution of conductivity due to changes in the cosmic ray flux and other energetic space particle fluxes, and at high magnetic latitudes from solar wind electric fields. Internal forcing arises from changes in the generators and changes in volcanic and anthropogenic aerosols in the troposphere and stratosphere. All these result in spatial and temporal variation in J z . Variations in J z affect the production of space charge in layer clouds, with the charges being transferred to droplets and aerosol particles. New observations and new analyses are consistent with non-negligible effects of the charges on the microphysics of such clouds. Observed effects are small, but of high statistical significance for cloud cover and precipitation changes, with resulting atmospheric temperature, pressure and dynamics changes. These effects are detectable on the day-to-day timescale for repeated J z changes of order 10%, and are thus second order electrical effects. The implicit first order effects have not, as yet, been incorporated into basic cloud and aerosol physics. Long term (multidecadal through millennial) global circuit changes, due to solar activity modulating the galactic cosmic ray flux, are an order of magnitude greater at high latitudes and in the stratosphere, as can be inferred from geological cosmogenic isotope records. Proxies for climate change in the same stratified depositories show strong correlations of climate with the inferred global

The global atmospheric electric circuit and its effects on cloud microphysics

Energy Technology Data Exchange (ETDEWEB)

Tinsley, B A [Physics Department and Center for Space Sciences, WT15, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX, 75080-3021 (United States)], E-mail: Tinsley@UTDallas.edu

2008-06-15

This review is an overview of progress in understanding the theory and observation of the global atmospheric electric circuit, with the focus on its dc aspects, and its short and long term variability. The effects of the downward ionosphere-earth current density, J{sub z}, on cloud microphysics, with its variability as an explanation for small observed changes in weather and climate, will also be reviewed. The global circuit shows responses to external as well as internal forcing. External forcing arises from changes in the distribution of conductivity due to changes in the cosmic ray flux and other energetic space particle fluxes, and at high magnetic latitudes from solar wind electric fields. Internal forcing arises from changes in the generators and changes in volcanic and anthropogenic aerosols in the troposphere and stratosphere. All these result in spatial and temporal variation in J{sub z}. Variations in J{sub z} affect the production of space charge in layer clouds, with the charges being transferred to droplets and aerosol particles. New observations and new analyses are consistent with non-negligible effects of the charges on the microphysics of such clouds. Observed effects are small, but of high statistical significance for cloud cover and precipitation changes, with resulting atmospheric temperature, pressure and dynamics changes. These effects are detectable on the day-to-day timescale for repeated J{sub z} changes of order 10%, and are thus second order electrical effects. The implicit first order effects have not, as yet, been incorporated into basic cloud and aerosol physics. Long term (multidecadal through millennial) global circuit changes, due to solar activity modulating the galactic cosmic ray flux, are an order of magnitude greater at high latitudes and in the stratosphere, as can be inferred from geological cosmogenic isotope records. Proxies for climate change in the same stratified depositories show strong correlations of climate with the

Using Amazon's Elastic Compute Cloud to scale CMS' compute hardware dynamically.

CERN Document Server

Melo, Andrew Malone

2011-01-01

Large international scientific collaborations such as the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider have traditionally addressed their data reduction and analysis needs by building and maintaining dedicated computational infrastructure. Emerging cloud-computing services such as Amazon's Elastic Compute Cloud (EC2) offer short-term CPU and storage resources with costs based on usage. These services allow experiments to purchase computing resources as needed, without significant prior planning and without long term investments in facilities and their management. We have demonstrated that services such as EC2 can successfully be integrated into the production-computing model of CMS, and find that they work very well as worker nodes. The cost-structure and transient nature of EC2 services makes them inappropriate for some CMS production services and functions. We also found that the resources are not truely on-demand as limits and caps on usage are imposed. Our trial workflows allow us t...

Scavenging of particulate elemental carbon into stratus cloud

Energy Technology Data Exchange (ETDEWEB)

Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

1995-12-31

The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

Scavenging of particulate elemental carbon into stratus cloud

Energy Technology Data Exchange (ETDEWEB)

Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

1996-12-31

The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

Stratocumulus Cloud Top Radiative Cooling and Cloud Base Updraft Speeds

Science.gov (United States)

Kazil, J.; Feingold, G.; Balsells, J.; Klinger, C.

2017-12-01

Cloud top radiative cooling is a primary driver of turbulence in the stratocumulus-topped marine boundary. A functional relationship between cloud top cooling and cloud base updraft speeds may therefore exist. A correlation of cloud top radiative cooling and cloud base updraft speeds has been recently identified empirically, providing a basis for satellite retrieval of cloud base updraft speeds. Such retrievals may enable analysis of aerosol-cloud interactions using satellite observations: Updraft speeds at cloud base co-determine supersaturation and therefore the activation of cloud condensation nuclei, which in turn co-determine cloud properties and precipitation formation. We use large eddy simulation and an off-line radiative transfer model to explore the relationship between cloud-top radiative cooling and cloud base updraft speeds in a marine stratocumulus cloud over the course of the diurnal cycle. We find that during daytime, at low cloud water path (CWP correlated, in agreement with the reported empirical relationship. During the night, in the absence of short-wave heating, CWP builds up (CWP > 50 g m-2) and long-wave emissions from cloud top saturate, while cloud base heating increases. In combination, cloud top cooling and cloud base updrafts become weakly anti-correlated. A functional relationship between cloud top cooling and cloud base updraft speed can hence be expected for stratocumulus clouds with a sufficiently low CWP and sub-saturated long-wave emissions, in particular during daytime. At higher CWPs, in particular at night, the relationship breaks down due to saturation of long-wave emissions from cloud top.

A State-of-the-Art Review of Cloud Forensics

Directory of Open Access Journals (Sweden)

Sameera Abdulrahman Almulla

2014-12-01

Full Text Available Cloud computing and digital forensics are emerging fields of technology. Unlike traditional digital forensics where the target environment can be almost completely acquired, isolated and can be under the investigators control; in cloud environments, the distribution of computation and storage poses unique and complex challenges to the investigators.Recently, the term "cloud forensics" has an increasing presence in the field of digital forensics. In this state-of-the-art review, we included the most recent research efforts that used "cloud forensics" as a keyword and then classify the literature in to three dimensions, (1 survey-based, (2 technology-based and (3 forensics procedural-based.We discuss widely accepted international standard bodies and their efforts to cope with the current trend of cloud forensics. Our aim is not only to reference related work based on the discussed dimensions, but also to analyze them and generate a mind map that will help in identifying research gaps. Finally, we summarize existing digital forensics tools and, the available simulation environments that can be used for evidence acquisition, examination and cloud forensics test purposes.

Modelling microphysical and meteorological controls on precipitation and cloud cellular structures in Southeast Pacific stratocumulus

Directory of Open Access Journals (Sweden)

H. Wang

2010-07-01

Full Text Available Microphysical and meteorological controls on the formation of open and closed cellular structures in the Southeast Pacific are explored using model simulations based on aircraft observations during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx. The effectiveness of factors such as boundary-layer moisture and temperature perturbations, surface heat and moisture fluxes, large-scale vertical motion and solar heating in promoting drizzle and open cell formation for prescribed aerosol number concentrations is explored. For the case considered, drizzle and subsequent open cell formation over a broad region are more sensitive to the observed boundary-layer moisture and temperature perturbations (+0.9 g kg⁻¹; −1 K than to a five-fold decrease in aerosol number concentration (150 vs. 30 mg⁻¹. When embedding the perturbations in closed cells, local drizzle and pockets of open cell (POC formation respond faster to the aerosol reduction than to the moisture increase, but the latter generates stronger and more persistent drizzle. A local negative perturbation in temperature drives a mesoscale circulation that prevents local drizzle formation but promotes it in a remote area where lower-level horizontal transport of moisture is blocked and converges to enhance liquid water path. This represents a potential mechanism for POC formation in the Southeast Pacific stratocumulus region whereby the circulation is triggered by strong precipitation in adjacent broad regions of open cells. A simulation that attempts to mimic the influence of a coastally induced upsidence wave results in an increase in cloud water but this alone is insufficient to initiate drizzle. An increase of surface sensible heat flux is also effective in triggering local drizzle and POC formation.

Both open and closed cells simulated with observed initial conditions exhibit distinct diurnal variations in cloud properties. A

Cloud networking understanding cloud-based data center networks

CERN Document Server

Lee, Gary

2014-01-01

Cloud Networking: Understanding Cloud-Based Data Center Networks explains the evolution of established networking technologies into distributed, cloud-based networks. Starting with an overview of cloud technologies, the book explains how cloud data center networks leverage distributed systems for network virtualization, storage networking, and software-defined networking. The author offers insider perspective to key components that make a cloud network possible such as switch fabric technology and data center networking standards. The final chapters look ahead to developments in architectures

Structure and trapping of three-dimensional dust clouds in a capacitively coupled rf-discharge

International Nuclear Information System (INIS)

Arp, O.; Block, D.; Piel, A.

2005-01-01

In this survey the recently found 'Coulomb balls' are discussed, which show an unusual kind of crystalline order. These three-dimensional dust clouds consisting of hundreds or thousands of micrometer-sized dust particles have a spherical shape and exist in a wide range of plasma conditions. Coulomb balls are optically highly transparent and have macroscopic dimensions of several millimeters in diameter. The clouds allow for the observation of each single particle and thus the complete reconstruction of the crystal structure by means of video microscopy techniques. The particles are arranged in distinct nested shells in which they form patterns with mostly five and six neighbors. The confinement of Coulomb balls by dielectric walls involves electric forces, surface charges, ion drag forces, and thermophoretic levitation. The thermophoretic force field is measured with tracer particles and particle image velocimetry (PIV). The electric forces are derived from simulations with the two-dimensional SIGLO-2D code. It is shown the the sum of all confining forces results in a stable potential well that describes levitation and spherical confinement of the Coulomb ball

Heat sources for bright-rimmed molecular clouds: CO observations of NGC 7822

International Nuclear Information System (INIS)

Elmegreen, B.G.; Dickinson, D.F.; Lada, C.J.

1978-01-01

Observations of the 2.6 mm carbon monoxide line in the bright rim NGC 7822 reveal that the peak excitation and column density of the molecule lie in a ridge ahead of the ionization front. Several possibilities for the excitation of this ridge are discussed. Cosmic rays are shown to provide an excellent heat source for Bok globules, but they can account for only approx.20% of the required heating in NGC 7822. Direct shock or compressional heating of the gas could be adequate only if the pressure inside the cloud is much larger than the thermal pressure. If, in fact, this internal pressure is determined by the source of line broadening (e.g., magnetic fields or turbulence), then shock or compressional heating could be important, and pressure equilibrium may exist between the neutral cloud and the bright rim. Heating by warm grains or by the photoelectric effect is also considered, but such mechanisms are probably not important if the only source of radiation is external to the cloud. This is primarily a result of the low cloud density (approx.10 3 cm -3 ) inferred from our observations. The extent to which unknown embedded stars may provide the required gaseous heating cannot be estimated from our observations of NGC 7822.An interesting and new heat source is suggested which may have important applications to bright-rimmed clouds or to any other predominantly neutral clouds that may have undergone some recent compression. We suggest that the heat input to neutral gas due to the relaxation of internal magnetic fields will be greatly enhanced during cloud compression (with or without a shock). We show that the power input to the gas will increase more with increasing density than will the cooling rate. As a result, cloud compression can lead to an increase in the gas temperature for a period lasting several million years, which is the decay time of the compressed field. The observed ridge in NGC 7822 may be due to stimulated release of internal magnetic energy

Comparison of Cloud and Aerosol Detection between CERES Edition 3 Cloud Mask and CALIPSO Version 2 Data Products

Science.gov (United States)

Trepte, Qing; Minnis, Patrick; Sun-Mack, Sunny; Trepte, Charles

Clouds and aerosol play important roles in the global climate system. Accurately detecting their presence, altitude, and properties using satellite radiance measurements is a crucial first step in determining their influence on surface and top-of-atmosphere radiative fluxes. This paper presents a comparison analysis of a new version of the Clouds and Earth's Radiant Energy System (CERES) Edition 3 cloud detection algorithms using Aqua MODIS data with the recently released Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Version 2 Vertical Feature Mask (VFM). Improvements in CERES Edition 3 cloud mask include dust detection, thin cirrus tests, enhanced low cloud detection at night, and a smoother transition from mid-latitude to polar regions. For the CALIPSO Version 2 data set, changes to the lidar calibration can result in significant improvements to its identification of optically thick aerosol layers. The Aqua and CALIPSO satellites, part of the A-train satellite constellation, provide a unique opportunity for validating passive sensor cloud and aerosol detection using an active sensor. In this paper, individual comparison cases will be discussed for different types of clouds and aerosols over various surfaces, for daytime and nighttime conditions, and for regions ranging from the tropics to the poles. Examples will include an assessment of the CERES detection algorithm for optically thin cirrus, marine stratus, and polar night clouds as well as its ability to characterize Saharan dust plumes off the African coast. With the CALIPSO lidar's unique ability to probe the vertical structure of clouds and aerosol layers, it provides an excellent validation data set for cloud detection algorithms, especially for polar nighttime clouds.

Plasma cloud expansion in the ionosphere: Three-dimensional simulation

International Nuclear Information System (INIS)

Ma, T.Z.; Schunk, R.W.

1991-01-01

A three-dimensional time-dependent model was developed to study the characteristics of a plasma cloud expansion in the ionosphere. The electrostatic potential is solved in three dimensions taking into account the large parallel-to-perpendicular conductivity ratio. Three sample simulations are presented: a plasma expansion of a nearly spherical 1 km Ba + cloud, both with and without a background neutral wind, and a long thin Ba + cloudlet. With or without the neutral wind the effective potential, which is different from the electrostatic potential if the electron temperature is included, is constant along the magnetic field for typical cloud sizes. The expanding plasma clouds become elongated in the magnetic field direction. The released Ba + ions push the background O + ions away along the magnetic field as they expand. Consequently, a hole develops in the background O + distribution at the cloud location and on the two sides of the cloud O + bumps form. The entire three-dimensional structure, composed of the plasma cloud and the background plasma embedded in the cloud, slowly rotates about the magnetic field, with the ions and electrons rotating in opposite directions. The cloud configuration takes the shape of a rotating ellipsoid with a major axis that expands with time. Perpendicular to the magnetic field, in the absence of the neutral wind the motion is insignificant compared to the parallel motion. With a neutral wind the motion along the magnetic field and the rotational motion are qualitatively unchanged, but the cloud and the perturbed background structure move in the direction of the wind, with a speed less than the wind speed. Perpendicular to the magnetic field the deformation of the cloud indiced by the wind is characterized by steepening of the backside

The MJO Transition from Shallow to Deep Convection in CloudSat/CALIPSO Data and GISS GCM Simulations

Science.gov (United States)

DelGenio, Anthony G.; Chen, Yonghua; Kim, Daehyun; Yao, Mao-Sung

2013-01-01

The relationship between convective penetration depth and tropospheric humidity is central to recent theories of the Madden-Julian oscillation (MJO). It has been suggested that general circulation models (GCMs) poorly simulate the MJO because they fail to gradually moisten the troposphere by shallow convection and simulate a slow transition to deep convection. CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data are analyzed to document the variability of convection depth and its relation to water vapor during the MJO transition from shallow to deep convection and to constrain GCM cumulus parameterizations. Composites of cloud occurrence for 10MJO events show the following anticipatedMJO cloud structure: shallow and congestus clouds in advance of the peak, deep clouds near the peak, and upper-level anvils after the peak. Cirrus clouds are also frequent in advance of the peak. The Advanced Microwave Scanning Radiometer for EarthObserving System (EOS) (AMSR-E) columnwater vapor (CWV) increases by;5 mmduring the shallow- deep transition phase, consistent with the idea of moisture preconditioning. Echo-top height of clouds rooted in the boundary layer increases sharply with CWV, with large variability in depth when CWV is between;46 and 68 mm. International Satellite Cloud Climatology Project cloud classifications reproduce these climatological relationships but correctly identify congestus-dominated scenes only about half the time. A version of the Goddard Institute for Space Studies Model E2 (GISS-E2) GCM with strengthened entrainment and rain evaporation that produces MJO-like variability also reproduces the shallow-deep convection transition, including the large variability of cloud-top height at intermediate CWV values. The variability is due to small grid-scale relative humidity and lapse rate anomalies for similar values of CWV. 1.

The International Standards Organisation offshore structures standard

International Nuclear Information System (INIS)

Snell, R.O.

1994-01-01

The International Standards Organisation has initiated a program to develop a suite of ISO Codes and Standards for the Oil Industry. The Offshore Structures Standard is one of seven topics being addressed. The scope of the standard will encompass fixed steel and concrete structures, floating structures, Arctic structures and the site specific assessment of mobile drilling and accommodation units. The standard will use as base documents the existing recommended practices and standards most frequently used for each type of structure, and will develop them to incorporate best published and recognized practice and knowledge where it provides a significant improvement on the base document. Work on the Code has commenced under the direction of an internationally constituted sub-committee comprising representatives from most of the countries with a substantial offshore oil and gas industry. This paper outlines the background to the code and the format, content and work program

Investigation of Seasonal Landscape Freeze/Thaw Cycles in Relation to Cloud Structure in the High Northern Latitudes

Science.gov (United States)

Smith, Cosmo

2011-01-01

The seasonal freezing and thawing of Earth's cryosphere (the portion of Earth's surface permanently or seasonally frozen) has an immense impact on Earth's climate as well as on its water, carbon and energy cycles. During the spring, snowmelt and the transition between frozen and non-frozen states lowers Earth's surface albedo. This change in albedo causes more solar radiation to be absorbed by the land surface, raising surface soil and air temperatures as much as 5 C within a few days. The transition of ice into liquid water not only raises the surface humidity, but also greatly affects the energy exchange between the land surface and the atmosphere as the phase change creates a latent energy dominated system. There is strong evidence to suggest that the thawing of the cryosphere during spring and refreezing during autumn is correlated to local atmospheric conditions such as cloud structure and frequency. Understanding the influence of land surface freeze/thaw cycles on atmospheric structure can help improve our understanding of links between seasonal land surface state and weather and climate, providing insight into associated changes in Earth's water, carbon, and energy cycles that are driven by climate change.Information on both the freeze/thaw states of Earth's land surface and cloud characteristics is derived from data sets collected by NOAA's Special Sensor Microwave/Imager (SSM/I), the Advanced Microwave Scanning Radiometer on NASA's Earth Observing System(AMSR-E), NASA's CloudSat, and NASA's SeaWinds-on-QuickSCAT Earth remote sensing satellite instruments. These instruments take advantage of the microwave spectrum to collect an ensemble of atmospheric and land surface data. Our analysis uses data from radars (active instruments which transmit a microwave signal toward Earth and measure the resultant backscatter) and radiometers (passive devices which measure Earth's natural microwave emission) to accurately characterize salient details on Earth's surface

Normalization and calibration of geostationary satellite radiances for the International Satellite Cloud Climatology Project

Science.gov (United States)

Desormeaux, Yves; Rossow, William B.; Brest, Christopher L.; Campbell, G. G.

1993-01-01

Procedures are described for normalizing the radiometric calibration of image radiances obtained from geostationary weather satellites that contributed data to the International Satellite Cloud Climatology Project. The key step is comparison of coincident and collocated measurements made by each satellite and the concurrent AVHRR on the 'afternoon' NOAA polar-orbiting weather satellite at the same viewing geometry. The results of this comparison allow transfer of the AVHRR absolute calibration, which has been established over the whole series, to the radiometers on the geostationary satellites. Results are given for Meteosat-2, 3, and 4, for GOES-5, 6, and 7, for GMS-2, 3, and 4 and for Insat-1B. The relative stability of the calibrations of these radiance data is estimated to be within +/- 3 percent; the uncertainty of the absolute calibrations is estimated to be less than 10 percent. The remaining uncertainties are at least two times smaller than for the original radiance data.

Internal structure of magnetic endosomes

Science.gov (United States)

Rivière, C.; Wilhelm, C.; Cousin, F.; Dupuis, V.; Gazeau, F.; Perzynski, R.

2007-01-01

The internal structure of biological vesicles filled with magnetic nanoparticles is investigated using the following complementary analyses: electronic transmission microscopy, dynamic probing by magneto-optical birefringence and structural probing by Small Angle Neutron Scattering (SANS). These magnetic vesicles are magnetic endosomes obtained via a non-specific interaction between cells and anionic magnetic iron oxide nanoparticles. Thanks to a magnetic purification process, they are probed at two different stages of their formation within HeLa cells: (i) adsorption of nanoparticles onto the cellular membrane and (ii) their subsequent internalisation within endosomes. Differences in the microenvironment of the magnetic nanoparticles at those two different stages are highlighted here. The dynamics of magnetic nanoparticles adsorbed onto cellular membranes and confined within endosomes is respectively 3 and 5 orders of magnitude slower than for isolated magnetic nanoparticles in aqueous media. Interestingly, SANS experiments show that magnetic endosomes have an internal structure close to decorated vesicles, with magnetic nanoparticles locally decorating the endosome membrane, inside their inner-sphere. These results, important for future biomedical applications, suggest that multiple fusions of decorated vesicles are the biological processes underlying the endocytosis of that kind of nanometric materials.

Evaluation of Passive Multilayer Cloud Detection Using Preliminary CloudSat and CALIPSO Cloud Profiles

Science.gov (United States)

Minnis, P.; Sun-Mack, S.; Chang, F.; Huang, J.; Nguyen, L.; Ayers, J. K.; Spangenberg, D. A.; Yi, Y.; Trepte, C. R.

2006-12-01

During the last few years, several algorithms have been developed to detect and retrieve multilayered clouds using passive satellite data. Assessing these techniques has been difficult due to the need for active sensors such as cloud radars and lidars that can "see" through different layers of clouds. Such sensors have been available only at a few surface sites and on aircraft during field programs. With the launch of the CALIPSO and CloudSat satellites on April 28, 2006, it is now possible to observe multilayered systems all over the globe using collocated cloud radar and lidar data. As part of the A- Train, these new active sensors are also matched in time ad space with passive measurements from the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer - EOS (AMSR-E). The Clouds and the Earth's Radiant Energy System (CERES) has been developing and testing algorithms to detect ice-over-water overlapping cloud systems and to retrieve the cloud liquid path (LWP) and ice water path (IWP) for those systems. One technique uses a combination of the CERES cloud retrieval algorithm applied to MODIS data and a microwave retrieval method applied to AMSR-E data. The combination of a CO2-slicing cloud retireval technique with the CERES algorithms applied to MODIS data (Chang et al., 2005) is used to detect and analyze such overlapped systems that contain thin ice clouds. A third technique uses brightness temperature differences and the CERES algorithms to detect similar overlapped methods. This paper uses preliminary CloudSat and CALIPSO data to begin a global scale assessment of these different methods. The long-term goals are to assess and refine the algorithms to aid the development of an optimal combination of the techniques to better monitor ice 9and liquid water clouds in overlapped conditions.

Single-Column Model Simulations of Subtropical Marine Boundary-Layer Cloud Transitions Under Weakening Inversions: SCM SIMULATIONS OF CLOUD TRANSITIONS

Energy Technology Data Exchange (ETDEWEB)

Neggers, R. A. J. [Institute for Geophysics and Meteorology, Department of Geosciences, University of Cologne, Cologne Germany; Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Ackerman, A. S. [NASA Goddard Institute for Space Studies, New York NY USA; Angevine, W. M. [CIRES, University of Colorado, Boulder CO USA; NOAA Earth System Research Laboratory, Boulder CO USA; Bazile, E. [Météo France/CNRM, Toulouse France; Beau, I. [Météo France/ENM, Toulouse France; Blossey, P. N. [Department of Atmospheric Sciences, University of Washington, Seattle WA USA; Boutle, I. A. [Met Office, Exeter UK; de Bruijn, C. [Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Cheng, A. [NOAA Center for Weather and Climate Prediction, Environmental Modeling Center, College Park MD USA; van der Dussen, J. [Department of Geoscience and Remote Sensing, Delft University of Technology, Delft The Netherlands; Fletcher, J. [Department of Atmospheric Sciences, University of Washington, Seattle WA USA; University of Leeds, Leeds UK; Dal Gesso, S. [Institute for Geophysics and Meteorology, Department of Geosciences, University of Cologne, Cologne Germany; Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Jam, A. [Météo-France/CNRM & CNRS/IPSL/LMD, Toulouse France; Kawai, H. [Meteorological Research Institute, Climate Research Department, Japan Meteorological Agency, Tsukuba Japan; Cheedela, S. K. [Department of Atmosphere in the Earth System, Max-Planck Institut für Meteorologie, Hamburg Germany; Larson, V. E. [Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee WI USA; Lefebvre, M. -P. [Météo-France/CNRM & CNRS/IPSL/LMD, Toulouse France; Lock, A. P. [Met Office, Exeter UK; Meyer, N. R. [Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee WI USA; de Roode, S. R. [Department of Geoscience and Remote Sensing, Delft University of Technology, Delft The Netherlands; de Rooy, W. [Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Sandu, I. [Section of Physical Aspects, European Centre for Medium-Range Weather Forecasts, Reading UK; Xiao, H. [University of California at Los Angeles, Los Angeles CA USA; Pacific Northwest National Laboratory, Richland WA USA; Xu, K. -M. [NASA Langley Research Centre, Hampton VI USA

2017-10-01

Results are presented of the GASS/EUCLIPSE single-column model inter-comparison study on the subtropical marine low-level cloud transition. A central goal is to establish the performance of state-of-the-art boundary-layer schemes for weather and climate mod- els for this cloud regime, using large-eddy simulations of the same scenes as a reference. A novelty is that the comparison covers four different cases instead of one, in order to broaden the covered parameter space. Three cases are situated in the North-Eastern Pa- cific, while one reflects conditions in the North-Eastern Atlantic. A set of variables is considered that reflects key aspects of the transition process, making use of simple met- rics to establish the model performance. Using this method some longstanding problems in low level cloud representation are identified. Considerable spread exists among models concerning the cloud amount, its vertical structure and the associated impact on radia- tive transfer. The sign and amplitude of these biases differ somewhat per case, depending on how far the transition has progressed. After cloud breakup the ensemble median ex- hibits the well-known “too few too bright” problem. The boundary layer deepening rate and its state of decoupling are both underestimated, while the representation of the thin capping cloud layer appears complicated by a lack of vertical resolution. Encouragingly, some models are successful in representing the full set of variables, in particular the verti- cal structure and diurnal cycle of the cloud layer in transition. An intriguing result is that the median of the model ensemble performs best, inspiring a new approach in subgrid pa- rameterization.

Cloud Computing Fundamentals

Science.gov (United States)

Furht, Borko

In the introductory chapter we define the concept of cloud computing and cloud services, and we introduce layers and types of cloud computing. We discuss the differences between cloud computing and cloud services. New technologies that enabled cloud computing are presented next. We also discuss cloud computing features, standards, and security issues. We introduce the key cloud computing platforms, their vendors, and their offerings. We discuss cloud computing challenges and the future of cloud computing.

Effect of chemical structure on the cloud point of some new non-ionic surfactants based on bisphenol in relation to their surface active properties

Directory of Open Access Journals (Sweden)

A.M. Al-Sabagh

2011-06-01

Full Text Available A series of non-ionic surfactants were prepared from bisphenol derived from acetone (A, acetophenone (AC and cyclohexanone (CH. The prepared bisphenols were ethoxylated at different degrees of ethylene oxide (27, 35, 43. The ethoxylated bisphenols were non-esterified by fatty acids; decanoic, lauric, myristic, palmitic, stearic, oleic, linoloic and linolinic. Some surface active properties for these surfactants were measured and calculated such as, surface tension [γ], critical micelle concentration [CMC], minimum area per molecule [Amin], surface excess [Cmax], free energy of micellization and adsorption [ΔGmic] and [ΔGads]. At a certain temperature, the cloud point was measured for these surfactants. From the obtained data it was found that; the cloud point is very sensitive to the increase of the alkyl chain length, content of ethylene oxide and degree of unsaturation. The core of bisphenol affected the cloud point sharply and they are ranked regarding bisphenol structure as BA > BCH > BAC. By inspection of the surface active properties of these surfactants, a good relation was obtained with their cloud points. The data were discussed on the light of their chemical structures.

Non-linear Q-clouds around Kerr black holes

International Nuclear Information System (INIS)

Herdeiro, Carlos; Radu, Eugen; Rúnarsson, Helgi

2014-01-01

Q-balls are regular extended ‘objects’ that exist for some non-gravitating, self-interacting, scalar field theories with a global, continuous, internal symmetry, on Minkowski spacetime. Here, analogous objects are also shown to exist around rotating (Kerr) black holes, as non-linear bound states of a test scalar field. We dub such configurations Q-clouds. We focus on a complex massive scalar field with quartic plus hexic self-interactions. Without the self-interactions, linear clouds have been shown to exist, in synchronous rotation with the black hole horizon, along 1-dimensional subspaces – existence lines – of the Kerr 2-dimensional parameter space. They are zero modes of the superradiant instability. Non-linear Q-clouds, on the other hand, are also in synchronous rotation with the black hole horizon; but they exist on a 2-dimensional subspace, delimited by a minimal horizon angular velocity and by an appropriate existence line, wherein the non-linear terms become irrelevant and the Q-cloud reduces to a linear cloud. Thus, Q-clouds provide an example of scalar bound states around Kerr black holes which, generically, are not zero modes of the superradiant instability. We describe some physical properties of Q-clouds, whose backreaction leads to a new family of hairy black holes, continuously connected to the Kerr family

Meteorological observations in support of a hill cap cloud experiment

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Morten

1998-06-01

Humid air flows form a hill cap cloud over the Agana mountain ridge in the north-east of Tenerife. The HILLCLOUD project utilised this cloud formation to investigate the chemical and physical properties of cloud aerosols by land based observations. The project was part of the second Aerosol characterisation Experiment (ACE-2) of the International Global Atmospheric chemistry project (IGAC). The present report describes meteorological observations in support of the hill cap cloud experiment. Time-series of wind speed, wind direction, temperature and humidity were collected at ground-based meteorological stations during a period starting one year in advance of the main campaign. A series of radiosonde detecting the upstream stability and wind profile were launched during the main campaign. (au) 5 tabs., 32 ills., 6 refs.

Internal structure of reactor building for Madras Atomic Power Project

International Nuclear Information System (INIS)

Pandit, D.P.

1975-01-01

The structural configuration and analysis of structural elements of the internal structure of reactor building for the Madras Atomic Power Project has been presented. Two methods of analysis of the internal structure, viz. Equivalent Plane Frame and Finite Element Method, are explained and compared with the use of bending moments obtained. (author)

Relationships among cloud occurrence frequency, overlap, and effective thickness derived from CALIPSO and CloudSat merged cloud vertical profiles

Science.gov (United States)

Kato, Seiji; Sun-Mack, Sunny; Miller, Walter F.; Rose, Fred G.; Chen, Yan; Minnis, Patrick; Wielicki, Bruce A.

2010-01-01

A cloud frequency of occurrence matrix is generated using merged cloud vertical profiles derived from the satellite-borne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and cloud profiling radar. The matrix contains vertical profiles of cloud occurrence frequency as a function of the uppermost cloud top. It is shown that the cloud fraction and uppermost cloud top vertical profiles can be related by a cloud overlap matrix when the correlation length of cloud occurrence, which is interpreted as an effective cloud thickness, is introduced. The underlying assumption in establishing the above relation is that cloud overlap approaches random overlap with increasing distance separating cloud layers and that the probability of deviating from random overlap decreases exponentially with distance. One month of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat data (July 2006) support these assumptions, although the correlation length sometimes increases with separation distance when the cloud top height is large. The data also show that the correlation length depends on cloud top hight and the maximum occurs when the cloud top height is 8 to 10 km. The cloud correlation length is equivalent to the decorrelation distance introduced by Hogan and Illingworth (2000) when cloud fractions of both layers in a two-cloud layer system are the same. The simple relationships derived in this study can be used to estimate the top-of-atmosphere irradiance difference caused by cloud fraction, uppermost cloud top, and cloud thickness vertical profile differences.

Security and Interdependency in a Public Cloud: A Game Theoretic Approach

Science.gov (United States)

2014-08-29

maximum utility can be reached (i.e., Pareto efficiency). However, the examples of perverse incentives and information inequality (where this feedback...interdependent structure. Cloud computing gives way to two types of interdependent relationships: cloud host-to- client and cloud client -to- client ... Client -to- client interdependency is much less studied than to the above-mentioned cloud host-to- client relationship. Although, it can still carry the

EEC-sponsored theoretical studies of gas cloud explosion pressure loadings

International Nuclear Information System (INIS)

Briscoe, F.; Curtress, N.; Farmer, C.L.; Fogg, G.J.; Vaughan, G.J.

1979-01-01

Estimates of the pressure loadings produced by unconfined gas cloud explosions on the surface of structures are required to assist the design of strong secondary containments in countries where the protection of nuclear installations against these events is considered to be necessary. At the present time, one difficulty in the specification of occurate pressure loadings arises from our lack of knowledge concerning the interaction between the incident pressure waves produced by unconfined gas cloud explosions and large structures. Preliminary theoretical studies include (i) general theoretical considerations, especially with regard to scaling (ii) investigations of the deflagration wave interaction with a wall based on an analytic solution for situations with planar symmetry and the application of an SRD gas cloud explosion code (GASEX 1) for situations with planar and spherical symmetry, and (iii) investigations of the interaction between shock waves and structures for situations with two-dimensional symmetry based on the application of another SRD gas cloud explosion code (GASEX 2)

High-mass star formation possibly triggered by cloud-cloud collision in the H II region RCW 34

Science.gov (United States)

Hayashi, Katsuhiro; Sano, Hidetoshi; Enokiya, Rei; Torii, Kazufumi; Hattori, Yusuke; Kohno, Mikito; Fujita, Shinji; Nishimura, Atsushi; Ohama, Akio; Yamamoto, Hiroaki; Tachihara, Kengo; Hasegawa, Yutaka; Kimura, Kimihiro; Ogawa, Hideo; Fukui, Yasuo

2018-05-01

We report on the possibility that the high-mass star located in the H II region RCW 34 was formed by a triggering induced by a collision of molecular clouds. Molecular gas distributions of the 12CO and 13CO J = 2-1 and 12CO J = 3-2 lines in the direction of RCW 34 were measured using the NANTEN2 and ASTE telescopes. We found two clouds with velocity ranges of 0-10 km s-1 and 10-14 km s-1. Whereas the former cloud is as massive as ˜1.4 × 104 M⊙ and has a morphology similar to the ring-like structure observed in the infrared wavelengths, the latter cloud, with a mass of ˜600 M⊙, which has not been recognized by previous observations, is distributed to just cover the bubble enclosed by the other cloud. The high-mass star with a spectral type of O8.5V is located near the boundary of the two clouds. The line intensity ratio of 12CO J = 3-2/J = 2-1 yields high values (≳1.0), suggesting that these clouds are associated with the massive star. We also confirm that the obtained position-velocity diagram shows a similar distribution to that derived by a numerical simulation of the supersonic collision of two clouds. Using the relative velocity between the two clouds (˜5 km s-1), the collisional time scale is estimated to be ˜0.2 Myr with the assumption of a distance of 2.5 kpc. These results suggest that the high-mass star in RCW 34 was formed rapidly within a time scale of ˜0.2 Myr via a triggering of a cloud-cloud collision.

High-performance scientific computing in the cloud

Science.gov (United States)

Jorissen, Kevin; Vila, Fernando; Rehr, John

2011-03-01

Cloud computing has the potential to open up high-performance computational science to a much broader class of researchers, owing to its ability to provide on-demand, virtualized computational resources. However, before such approaches can become commonplace, user-friendly tools must be developed that hide the unfamiliar cloud environment and streamline the management of cloud resources for many scientific applications. We have recently shown that high-performance cloud computing is feasible for parallelized x-ray spectroscopy calculations. We now present benchmark results for a wider selection of scientific applications focusing on electronic structure and spectroscopic simulation software in condensed matter physics. These applications are driven by an improved portable interface that can manage virtual clusters and run various applications in the cloud. We also describe a next generation of cluster tools, aimed at improved performance and a more robust cluster deployment. Supported by NSF grant OCI-1048052.

Clustering, randomness, and regularity in cloud fields: 2. Cumulus cloud fields

Science.gov (United States)

Zhu, T.; Lee, J.; Weger, R. C.; Welch, R. M.

1992-12-01

During the last decade a major controversy has been brewing concerning the proper characterization of cumulus convection. The prevailing view has been that cumulus clouds form in clusters, in which cloud spacing is closer than that found for the overall cloud field and which maintains its identity over many cloud lifetimes. This "mutual protection hypothesis" of Randall and Huffman (1980) has been challenged by the "inhibition hypothesis" of Ramirez et al. (1990) which strongly suggests that the spatial distribution of cumuli must tend toward a regular distribution. A dilemma has resulted because observations have been reported to support both hypotheses. The present work reports a detailed analysis of cumulus cloud field spatial distributions based upon Landsat, Advanced Very High Resolution Radiometer, and Skylab data. Both nearest-neighbor and point-to-cloud cumulative distribution function statistics are investigated. The results show unequivocally that when both large and small clouds are included in the cloud field distribution, the cloud field always has a strong clustering signal. The strength of clustering is largest at cloud diameters of about 200-300 m, diminishing with increasing cloud diameter. In many cases, clusters of small clouds are found which are not closely associated with large clouds. As the small clouds are eliminated from consideration, the cloud field typically tends towards regularity. Thus it would appear that the "inhibition hypothesis" of Ramirez and Bras (1990) has been verified for the large clouds. However, these results are based upon the analysis of point processes. A more exact analysis also is made which takes into account the cloud size distributions. Since distinct clouds are by definition nonoverlapping, cloud size effects place a restriction upon the possible locations of clouds in the cloud field. The net effect of this analysis is that the large clouds appear to be randomly distributed, with only weak tendencies towards

International Symposium on Grids and Clouds (ISGC) 2017

Science.gov (United States)

2017-03-01

The International Symposium on Grids and Clouds (ISGC) 2017 will be held at Academia Sinica in Taipei, Taiwan from 5-10 March 2017, with co- located events and workshops. The main theme of ISGC 2017 is "Global Challenges: From Open Data to Open Science". The unprecedented progress in ICT has transformed the way education is conducted and research is carried out. The emerging global e-Infrastructure, championed by global science communities such as High Energy Physics, Astronomy, and Bio- medicine, must permeate into other sciences. Many areas, such as climate change, disaster mitigation, and human sustainability and well-being, represent global challenges where collaboration over e-Infrastructure will presumably help resolve the common problems of the people who are impacted. Access to global e-Infrastructure helps also the less globally organized, long-tail sciences, with their own collaboration challenges. Open data are not only a political phenomenon serving government transparency; they also create an opportunity to eliminate access barriers to all scientific data, specifically data from global sciences and regional data that concern natural phenomena and people. In this regard, the purpose of open data is to improve sciences, accelerating specifically those that may benefit people. Nevertheless, to eliminate barriers to open data is itself a daunting task and the barriers to individuals, institutions and big collaborations are manifold. Open science is a step beyond open data, where the tools and understanding of scientific data must be made available to whoever is interested to participate in such scientific research. The promotion of open science may change the academic tradition practiced over the past few hundred years. This change of dynamics may contribute to the resolution of common challenges of human sustainability where the current pace of scientific progress is not sufficiently fast. ISGC 2017 created a face-to-face venue where individual

Cloud Computing for Mission Design and Operations

Science.gov (United States)

Arrieta, Juan; Attiyah, Amy; Beswick, Robert; Gerasimantos, Dimitrios

2012-01-01

The space mission design and operations community already recognizes the value of cloud computing and virtualization. However, natural and valid concerns, like security, privacy, up-time, and vendor lock-in, have prevented a more widespread and expedited adoption into official workflows. In the interest of alleviating these concerns, we propose a series of guidelines for internally deploying a resource-oriented hub of data and algorithms. These guidelines provide a roadmap for implementing an architecture inspired in the cloud computing model: associative, elastic, semantical, interconnected, and adaptive. The architecture can be summarized as exposing data and algorithms as resource-oriented Web services, coordinated via messaging, and running on virtual machines; it is simple, and based on widely adopted standards, protocols, and tools. The architecture may help reduce common sources of complexity intrinsic to data-driven, collaborative interactions and, most importantly, it may provide the means for teams and agencies to evaluate the cloud computing model in their specific context, with minimal infrastructure changes, and before committing to a specific cloud services provider.

Comparison of cloud top heights derived from FY-2 meteorological satellites with heights derived from ground-based millimeter wavelength cloud radar

Science.gov (United States)

Wang, Zhe; Wang, Zhenhui; Cao, Xiaozhong; Tao, Fa

2018-01-01

Clouds are currently observed by both ground-based and satellite remote sensing techniques. Each technique has its own strengths and weaknesses depending on the observation method, instrument performance and the methods used for retrieval. It is important to study synergistic cloud measurements to improve the reliability of the observations and to verify the different techniques. The FY-2 geostationary orbiting meteorological satellites continuously observe the sky over China. Their cloud top temperature product can be processed to retrieve the cloud top height (CTH). The ground-based millimeter wavelength cloud radar can acquire information about the vertical structure of clouds-such as the cloud base height (CBH), CTH and the cloud thickness-and can continuously monitor changes in the vertical profiles of clouds. The CTHs were retrieved using both cloud top temperature data from the FY-2 satellites and the cloud radar reflectivity data for the same time period (June 2015 to May 2016) and the resulting datasets were compared in order to evaluate the accuracy of CTH retrievals using FY-2 satellites. The results show that the concordance rate of cloud detection between the two datasets was 78.1%. Higher consistencies were obtained for thicker clouds with larger echo intensity and for more continuous clouds. The average difference in the CTH between the two techniques was 1.46 km. The difference in CTH between low- and mid-level clouds was less than that for high-level clouds. An attenuation threshold of the cloud radar for rainfall was 0.2 mm/min; a rainfall intensity below this threshold had no effect on the CTH. The satellite CTH can be used to compensate for the attenuation error in the cloud radar data.

Recent Trends of the Tropical Hydrological Cycle Inferred from Global Precipitation Climatology Project and International Satellite Cloud Climatology Project data

Science.gov (United States)

Zhou, Y. P.; Xu, Kuan-Man; Sud, Y. C.; Betts, A. K.

2011-01-01

Scores of modeling studies have shown that increasing greenhouse gases in the atmosphere impact the global hydrologic cycle; however, disagreements on regional scales are large, and thus the simulated trends of such impacts, even for regions as large as the tropics, remain uncertain. The present investigation attempts to examine such trends in the observations using satellite data products comprising Global Precipitation Climatology Project precipitation and International Satellite Cloud Climatology Project cloud and radiation. Specifically, evolving trends of the tropical hydrological cycle over the last 20-30 years were identified and analyzed. The results show (1) intensification of tropical precipitation in the rising regions of the Walker and Hadley circulations and weakening over the sinking regions of the associated overturning circulation; (2) poleward shift of the subtropical dry zones (up to 2deg/decade in June-July-August (JJA) in the Northern Hemisphere and 0.3-0.7deg/decade in June-July-August and September-October-November in the Southern Hemisphere) consistent with an overall broadening of the Hadley circulation; and (3) significant poleward migration (0.9-1.7deg/decade) of cloud boundaries of Hadley cell and plausible narrowing of the high cloudiness in the Intertropical Convergence Zone region in some seasons. These results support findings of some of the previous studies that showed strengthening of the tropical hydrological cycle and expansion of the Hadley cell that are potentially related to the recent global warming trends.

Comparisons of characteristics of magnetic clouds and cloud-like structures during 1995-2012

Science.gov (United States)

Lepping, R. P.; Wu, C. C.; Liou, K.

2014-12-01

Using eighteen years (1995-2012) of solar wind plasma and magnetic field data (observed by the Wind spacecraft), solar activity (e.g., sunspot number: SSN), and geomagnetic activity index (Dst), we have identified 168 magnetic clouds (MCs) and 197 magnetic cloud-like structures (MCLs), and we made relevant comparisons. The following features are found during seven different periods [Total Period (TP) during 1995-2012, first and second half period during 1995-2003 (P1) and 2004-2012 (P2), Quiet periods during 1995-1997 (Q1) and 2007-2009 (Q2), Active periods during 1998-2006 (A1) and 2010-2012 (A2)]. (1) During 1995-2012 the yearly occurrence frequency is TP = 9.3 for MCs and TP =10.9 for MCLs. (2) In the quiet periods, Q1,Q2 is higher than Q1,Q2 (i.e., Q1 > Q1 and Q2 > Q2), but Q1,Q2 is lower than during the active periods (i.e., A1 A1 and A2 A2). This is probably due to the lower interaction rate between MCs/MCLs and the quiet background solar wind during lower solar active periods in Q1, Q2, and higher interaction rate and highly disturbed background solar wind during the active periods in A1 and A2. (3) The minimum Bz (Bzmin) inside of a MC is well correlated with the intensity of geomagnetic activity, Dstmin (minimum Dst found within a storm event) for MCs (correlation coefficient, c.c. = 0.75 and the fitting function is Dstmin = -1.74+ 7.23 Bzmin), but Bzmin is not well correlated with MCLs (c.c. = 0.57). (4) MCs play a major role in producing geomagnetic storms: the absolute value of the average Dstmin for MCs (MC = -70 nT) associated geomagnetic storms is two times stronger than that for MCLs (MCL = -35 nT) due to the difference in the IMF (interplanetary magnetic field) strength. (5) Over the Total Period the SSN is not correlated with TP (c.c. = 0.27), but is well associated with TP (c.c. = 0.85). Note that the c.c. for SSN vs. P2 is better than that for SSN vs. P2. (6) Averages of IMF, solar wind speed, and density inside of the MCs are larger than those

Electron Cloud Effect in the Linear Colliders

International Nuclear Information System (INIS)

Pivi, M

2004-01-01

Beam induced multipacting, driven by the electric field of successive positively charged bunches, may arise from a resonant motion of electrons, generated by secondary emission, bouncing back and forth between opposite walls of the vacuum chamber. The electron-cloud effect (ECE) has been observed or is expected at many storage rings [1]. In the beam pipe of the Damping Ring (DR) of a linear collider, an electron cloud is produced initially by ionization of the residual gas and photoelectrons from the synchrotron radiation. The cloud is then sustained by secondary electron emission. This electron cloud can reach equilibrium after the passage of only a few bunches. The electron-cloud effect may be responsible for collective effects as fast coupled-bunch and single-bunch instability, emittance blow-up or incoherent tune shift when the bunch current exceeds a certain threshold, accompanied by a large number of electrons in the vacuum chamber. The ECE was identified as one of the most important R and D topics in the International Linear Collider Report [2]. Systematic studies on the possible electron-cloud effect have been initiated at SLAC for the GLC/NLC and TESLA linear colliders, with particular attention to the effect in the positron main damping ring (MDR) and the positron Low Emittance Transport which includes the bunch compressor system (BCS), the main linac, and the beam delivery system (BDS). We present recent computer simulation results for the main features of the electron cloud generation in both machine designs. Thus, single and coupled-bunch instability thresholds are estimated for the GLC/NLC design

Aerosol and Cloud Experiments in Eastern North Atlantic (ACE-ENA) Science Plan

Energy Technology Data Exchange (ETDEWEB)

Wang, Jian [Brookhaven National Lab. (BNL), Upton, NY (United States); Dong, Xiquan [Univ. of North Dakota, Grand Forks, ND (United States); Wood, Robert [Univ. of Washington, Seattle, WA (United States)

2016-04-01

With their extensive coverage, low clouds greatly impact global climate. Presently, low clouds are poorly represented in global climate models (GCMs), and the response of low clouds to changes in atmospheric greenhouse gases and aerosols remains the major source of uncertainty in climate simulations. The poor representations of low clouds in GCMs are in part due to inadequate observations of their microphysical and macrophysical structures, radiative effects, and the associated aerosol distribution and budget in regions where the aerosol impact is the greatest. The Eastern North Atlantic (ENA) is a region of persistent but diverse subtropical marine boundary-layer (MBL) clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. Boundary-layer aerosol in the ENA region is influenced by a variety of sources, leading to strong variations in cloud condensation nuclei (CCN) concentration and aerosol optical properties. Recently a permanent ENA site was established by the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility on Graciosa Island in the Azores, providing invaluable information on MBL aerosol and low clouds. At the same time, the vertical structures and horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol, the radiative properties, precipitation efficiency, and lifecycle of MBL clouds, and the cloud response to aerosol perturbations. Much of this data can be obtained only through aircraft-based measurements. In addition, the interconnected aerosol and cloud processes are best investigated by a study involving simultaneous in situ aerosol, cloud, and thermodynamics measurements. Furthermore, in situ measurements are also necessary for validating and improving ground-based retrieval algorithms at the ENA site. This project is motivated by the need

Opto-mechanical design of small infrared cloud measuring device

Science.gov (United States)

Zhang, Jiao; Yu, Xun; Tao, Yu; Jiang, Xu

2018-01-01

In order to make small infrared cloud measuring device can be well in a wide temperature range and day-night environment, a design idea using catadioptric infrared panoramic imaging optical system and simple mechanical structure for realizing observation clode under all-weather conditions was proposed. Firstly, the optical system of cloud measuring device was designed. An easy-to-use numerical method was proposed to acquire the profile of a catadioptric mirror, which brought the property of equidistance projection and played the most important role in a catadioptric panoramic lens. Secondly, the mechanical structure was studied in detail. Overcoming the limitations of traditional primary mirror support structure, integrative design was used for refractor and mirror support structure. Lastly, temperature adaptability and modes of the mirror support structure were analyzed. Results show that the observation range of the cloud measuring device is wide and the structure is simple, the fundamental frequency of the structure is greater than 100 Hz, the surface precision of the system reflector reaches PV of λ/10 and RMS of λ/40under the load of temperature range - 40 60°C, it can meet the needs of existing meteorological observation.

Cloud occurrences and cloud radiative effects (CREs) from CERES-CALIPSO-CloudSat-MODIS (CCCM) and CloudSat radar-lidar (RL) products

Science.gov (United States)

Ham, Seung-Hee; Kato, Seiji; Rose, Fred G.; Winker, David; L'Ecuyer, Tristan; Mace, Gerald G.; Painemal, David; Sun-Mack, Sunny; Chen, Yan; Miller, Walter F.

2017-08-01

Two kinds of cloud products obtained from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), CloudSat, and Moderate Resolution Imaging Spectroradiometer (MODIS) are compared and analyzed in this study: Clouds and the Earth's Radiant Energy System (CERES)-CALIPSO-CloudSat-MODIS (CCCM) product and CloudSat radar-lidar products such as GEOPROF-LIDAR and FLXHR-LIDAR. Compared to GEOPROF-LIDAR, low-level (40°). The difference occurs when hydrometeors are detected by CALIPSO lidar but are undetected by CloudSat radar. In the comparison of cloud radiative effects (CREs), global mean differences between CCCM and FLXHR-LIDAR are mostly smaller than 5 W m-2, while noticeable regional differences are found. For example, CCCM shortwave (SW) and longwave (LW) CREs are larger than FXLHR-LIDAR along the west coasts of Africa and America because the GEOPROF-LIDAR algorithm misses shallow marine boundary layer clouds. In addition, FLXHR-LIDAR SW CREs are larger than the CCCM counterpart over tropical oceans away from the west coasts of America. Over midlatitude storm-track regions, CCCM SW and LW CREs are larger than the FLXHR-LIDAR counterpart.

Relation of Cloud Occurrence Frequency, Overlap, and Effective Thickness Derived from CALIPSO and CloudSat Merged Cloud Vertical Profiles

Science.gov (United States)

Kato, Seiji; Sun-Mack, Sunny; Miller, Walter F.; Rose, Fred G.; Chen, Yan; Minnis, Patrick; Wielicki, Bruce A.

2009-01-01

A cloud frequency of occurrence matrix is generated using merged cloud vertical profile derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Cloud Profiling Radar (CPR). The matrix contains vertical profiles of cloud occurrence frequency as a function of the uppermost cloud top. It is shown that the cloud fraction and uppermost cloud top vertical pro les can be related by a set of equations when the correlation distance of cloud occurrence, which is interpreted as an effective cloud thickness, is introduced. The underlying assumption in establishing the above relation is that cloud overlap approaches the random overlap with increasing distance separating cloud layers and that the probability of deviating from the random overlap decreases exponentially with distance. One month of CALIPSO and CloudSat data support these assumptions. However, the correlation distance sometimes becomes large, which might be an indication of precipitation. The cloud correlation distance is equivalent to the de-correlation distance introduced by Hogan and Illingworth [2000] when cloud fractions of both layers in a two-cloud layer system are the same.

Planck intermediate results: XXXV. Probing the role of the magnetic field in the formation of structure in molecular clouds

International Nuclear Information System (INIS)

Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.; Arnaud, M.; Arzoumanian, D.

2016-01-01

Within ten nearby (d < 450 pc) Gould belt molecular clouds we evaluate in this paper statistically the relative orientation between the magnetic field projected on the plane of sky, inferred from the polarized thermal emission of Galactic dust observed by Planck at 353 GHz, and the gas column density structures, quantified by the gradient of the column density, N_H. The selected regions, covering several degrees in size, are analysed at an effective angular resolution of 10' FWHM, thus sampling physical scales from 0.4 to 40 pc in the nearest cloud. The column densities in the selected regions range from N_H≈ 10"2"1 to10"2"3 cm"-"2, and hence they correspond to the bulk of the molecular clouds. The relative orientation is evaluated pixel by pixel and analysed in bins of column density using the novel statistical tool called “histogram of relative orientations”. Throughout this study, we assume that the polarized emission observed by Planck at 353 GHz is representative of the projected morphology of the magnetic field in each region, i.e., we assume a constant dust grain alignment efficiency, independent of the local environment. Within most clouds we find that the relative orientation changes progressively with increasing N_H, from mostly parallel or having no preferred orientation to mostly perpendicular. In simulations of magnetohydrodynamic turbulence in molecular clouds this trend in relative orientation is a signature of Alfvénic or sub-Alfvénic turbulence, implying that the magnetic field is significant for the gas dynamics at the scales probed by Planck. Finally, we compare the deduced magnetic field strength with estimates we obtain from other methods and discuss the implications of the Planck observations for the general picture of molecular cloud formation and evolution.

A holistic image segmentation framework for cloud detection and extraction

Science.gov (United States)

Shen, Dan; Xu, Haotian; Blasch, Erik; Horvath, Gregory; Pham, Khanh; Zheng, Yufeng; Ling, Haibin; Chen, Genshe

2013-05-01

Atmospheric clouds are commonly encountered phenomena affecting visual tracking from air-borne or space-borne sensors. Generally clouds are difficult to detect and extract because they are complex in shape and interact with sunlight in a complex fashion. In this paper, we propose a clustering game theoretic image segmentation based approach to identify, extract, and patch clouds. In our framework, the first step is to decompose a given image containing clouds. The problem of image segmentation is considered as a "clustering game". Within this context, the notion of a cluster is equivalent to a classical equilibrium concept from game theory, as the game equilibrium reflects both the internal and external (e.g., two-player) cluster conditions. To obtain the evolutionary stable strategies, we explore three evolutionary dynamics: fictitious play, replicator dynamics, and infection and immunization dynamics (InImDyn). Secondly, we use the boundary and shape features to refine the cloud segments. This step can lower the false alarm rate. In the third step, we remove the detected clouds and patch the empty spots by performing background recovery. We demonstrate our cloud detection framework on a video clip provides supportive results.

All-sky photogrammetry techniques to georeference a cloud field

Science.gov (United States)

Crispel, Pierre; Roberts, Gregory

2018-01-01

In this study, we present a novel method of identifying and geolocalizing cloud field elements from a portable all-sky camera stereo network based on the ground and oriented towards zenith. The methodology is mainly based on stereophotogrammetry which is a 3-D reconstruction technique based on triangulation from corresponding stereo pixels in rectified images. In cases where clouds are horizontally separated, identifying individual positions is performed with segmentation techniques based on hue filtering and contour detection algorithms. Macroscopic cloud field characteristics such as cloud layer base heights and velocity fields are also deduced. In addition, the methodology is fitted to the context of measurement campaigns which impose simplicity of implementation, auto-calibration, and portability. Camera internal geometry models are achieved a priori in the laboratory and validated to ensure a certain accuracy in the peripheral parts of the all-sky image. Then, stereophotogrammetry with dense 3-D reconstruction is applied with cameras spaced 150 m apart for two validation cases. The first validation case is carried out with cumulus clouds having a cloud base height at 1500 m a.g.l. The second validation case is carried out with two cloud layers: a cumulus fractus layer with a base height at 1000 m a.g.l. and an altocumulus stratiformis layer with a base height of 2300 m a.g.l. Velocity fields at cloud base are computed by tracking image rectangular patterns through successive shots. The height uncertainty is estimated by comparison with a Vaisala CL31 ceilometer located on the site. The uncertainty on the horizontal coordinates and on the velocity field are theoretically quantified by using the experimental uncertainties of the cloud base height and camera orientation. In the first cumulus case, segmentation of the image is performed to identify individuals clouds in the cloud field and determine the horizontal positions of the cloud centers.

The Cloud2SM Project

Science.gov (United States)

Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barosso, Guillermo; Simonin, Matthieu

2015-04-01

From the past decades the monitoring of civil engineering structure became a major field of research and development process in the domains of modelling and integrated instrumentation. This increasing of interest can be attributed in part to the need of controlling the aging of such structures and on the other hand to the need to optimize maintenance costs. From this standpoint the project Cloud2SM (Cloud architecture design for Structural Monitoring with in-line Sensors and Models tasking), has been launched to develop a robust information system able to assess the long term monitoring of civil engineering structures as well as interfacing various sensors and data. The specificity of such architecture is to be based on the notion of data processing through physical or statistical models. Thus the data processing, whether material or mathematical, can be seen here as a resource of the main architecture. The project can be divided in various items: -The sensors and their measurement process: Those items provide data to the main architecture and can embed storage or computational resources. Dependent of onboard capacity and the amount of data generated it can be distinguished heavy and light sensors. - The storage resources: Based on the cloud concept this resource can store at least two types of data, raw data and processed ones. - The computational resources: This item includes embedded "pseudo real time" resources as the dedicated computer cluster or computational resources. - The models: Used for the conversion of raw data to meaningful data. Those types of resources inform the system of their needs they can be seen as independents blocks of the system. - The user interface: This item can be divided in various HMI to assess maintaining operation on the sensors or pop-up some information to the user. - The demonstrators: The structures themselves. This project follows previous research works initiated in the European project ISTIMES [1]. It includes the infrared

Relationship between Trustworthiness, Transparency, and Security in Cloud Computing Environments: A Regression Analysis

Science.gov (United States)

Ibrahim, Sara

2017-01-01

The insider security threat causes new and dangerous dimensions in cloud computing. Those internal threats are originated from contractors or the business partners' input that have access to the systems. A study of trustworthiness and transparency might assist the organizations to monitor employees' activity more cautiously on cloud technologies…

Contrasting Cloud Composition Between Coupled and Decoupled Marine Boundary Layer Clouds

Science.gov (United States)

WANG, Z.; Mora, M.; Dadashazar, H.; MacDonald, A.; Crosbie, E.; Bates, K. H.; Coggon, M. M.; Craven, J. S.; Xian, P.; Campbell, J. R.; AzadiAghdam, M.; Woods, R. K.; Jonsson, H.; Flagan, R. C.; Seinfeld, J.; Sorooshian, A.

2016-12-01

Marine stratocumulus clouds often become decoupled from the vertical layer immediately above the ocean surface. This study contrasts cloud chemical composition between coupled and decoupled marine stratocumulus clouds. Cloud water and droplet residual particle composition were measured in clouds off the California coast during three airborne experiments in July-August of separate years (E-PEACE 2011, NiCE 2013, BOAS 2015). Decoupled clouds exhibited significantly lower overall mass concentrations in both cloud water and droplet residual particles, consistent with reduced cloud droplet number concentration and sub-cloud aerosol (Dp > 100 nm) number concentration, owing to detachment from surface sources. Non-refractory sub-micrometer aerosol measurements show that coupled clouds exhibit higher sulfate mass fractions in droplet residual particles, owing to more abundant precursor emissions from the ocean and ships. Consequently, decoupled clouds exhibited higher mass fractions of organics, nitrate, and ammonium in droplet residual particles, owing to effects of long-range transport from more distant sources. Total cloud water mass concentration in coupled clouds was dominated by sodium and chloride, and their mass fractions and concentrations exceeded those in decoupled clouds. Conversely, with the exception of sea salt constituents (e.g., Cl, Na, Mg, K), cloud water mass fractions of all species examined were higher in decoupled clouds relative to coupled clouds. These results suggest that an important variable is the extent to which clouds are coupled to the surface layer when interpreting microphysical data relevant to clouds and aerosol particles.

Survey on Security Issues in File Management in Cloud Computing Environment

Science.gov (United States)

Gupta, Udit

2015-06-01

Cloud computing has pervaded through every aspect of Information technology in past decade. It has become easier to process plethora of data, generated by various devices in real time, with the advent of cloud networks. The privacy of users data is maintained by data centers around the world and hence it has become feasible to operate on that data from lightweight portable devices. But with ease of processing comes the security aspect of the data. One such security aspect is secure file transfer either internally within cloud or externally from one cloud network to another. File management is central to cloud computing and it is paramount to address the security concerns which arise out of it. This survey paper aims to elucidate the various protocols which can be used for secure file transfer and analyze the ramifications of using each protocol.

Chemistry and structure of giant molecular clouds in energetic environments

Science.gov (United States)

Anderson, Crystal Nicole

2016-09-01

Throughout the years many studies on Galactic star formation have been conducted. This resulted in the idea that giant molecular clouds (GMCs) are hierarchical in nature with substructures spanning a large range of sizes. The physical processes that determine how molecular clouds fragment, form clumps/cores and then stars depends strongly on both recent radiative and mechanical feed- back from massive stars and, on longer term, from enhanced cooling due to the buildup of metals. Radiative and mechanical energy input from stellar populations can alter subsequent star formation over a large part of a galaxy and hence is relevant to the evolution of galaxies. Much of our knowledge of star formation on galaxy wide scales is based on scaling laws and other parametric descriptions. But to understand the overall evolution of star formation in galaxies we need to watch the feedback processes at work on giant molecular cloud (GMC) scales. By doing this we can begin to answer how strong feedback environments change the properties of the substructure in GMCs. Tests of Galactic star formation theory to other galaxies has been a challenging process due to the lack of resolution with current instruments. Thus, only the nearest galaxies allow us to resolve GMCs and their substructures. The Large Magellanic Cloud (LMC), is one of the closest low metallicity dwarf galaxies (D˜ 50 kpc) and is close enough that current instruments can resolve the sub- structure of its GMCs to molecular gas tracers (e.g. HCO+, HCN, HNC, CS, C2H, N2H+) detected in the LMC at 1.5-40 pc scales and in NGC 5253 at 40 pc scales. I then compare the molecular gas detections to the Central Molecular Zone in our Galaxy. Dense molecular gas was detected in all of the sources. For the regions in the LMC, molecular lines of CS, N2H+, C 2H, HNC, HCO+ and HCN were all detected in N159W and N113 while only HCN, HCO+, HNC, and C2H were detected in 30Dor-10. Toward NGC 5253 only HCO+, HCN, C2H and CS were detected. I

Multi-Class Simultaneous Adaptive Segmentation and Quality Control of Point Cloud Data

Directory of Open Access Journals (Sweden)

Ayman Habib

2016-01-01

Full Text Available 3D modeling of a given site is an important activity for a wide range of applications including urban planning, as-built mapping of industrial sites, heritage documentation, military simulation, and outdoor/indoor analysis of airflow. Point clouds, which could be either derived from passive or active imaging systems, are an important source for 3D modeling. Such point clouds need to undergo a sequence of data processing steps to derive the necessary information for the 3D modeling process. Segmentation is usually the first step in the data processing chain. This paper presents a region-growing multi-class simultaneous segmentation procedure, where planar, pole-like, and rough regions are identified while considering the internal characteristics (i.e., local point density/spacing and noise level of the point cloud in question. The segmentation starts with point cloud organization into a kd-tree data structure and characterization process to estimate the local point density/spacing. Then, proceeding from randomly-distributed seed points, a set of seed regions is derived through distance-based region growing, which is followed by modeling of such seed regions into planar and pole-like features. Starting from optimally-selected seed regions, planar and pole-like features are then segmented. The paper also introduces a list of hypothesized artifacts/problems that might take place during the region-growing process. Finally, a quality control process is devised to detect, quantify, and mitigate instances of partially/fully misclassified planar and pole-like features. Experimental results from airborne and terrestrial laser scanning as well as image-based point clouds are presented to illustrate the performance of the proposed segmentation and quality control framework.

A portable low-cost 3D point cloud acquiring method based on structure light

Science.gov (United States)

Gui, Li; Zheng, Shunyi; Huang, Xia; Zhao, Like; Ma, Hao; Ge, Chao; Tang, Qiuxia

2018-03-01

A fast and low-cost method of acquiring 3D point cloud data is proposed in this paper, which can solve the problems of lack of texture information and low efficiency of acquiring point cloud data with only one pair of cheap cameras and projector. Firstly, we put forward a scene adaptive design method of random encoding pattern, that is, a coding pattern is projected onto the target surface in order to form texture information, which is favorable for image matching. Subsequently, we design an efficient dense matching algorithm that fits the projected texture. After the optimization of global algorithm and multi-kernel parallel development with the fusion of hardware and software, a fast acquisition system of point-cloud data is accomplished. Through the evaluation of point cloud accuracy, the results show that point cloud acquired by the method proposed in this paper has higher precision. What`s more, the scanning speed meets the demand of dynamic occasion and has better practical application value.

Context-aware distributed cloud computing using CloudScheduler

Science.gov (United States)

Seuster, R.; Leavett-Brown, CR; Casteels, K.; Driemel, C.; Paterson, M.; Ring, D.; Sobie, RJ; Taylor, RP; Weldon, J.

2017-10-01

The distributed cloud using the CloudScheduler VM provisioning service is one of the longest running systems for HEP workloads. It has run millions of jobs for ATLAS and Belle II over the past few years using private and commercial clouds around the world. Our goal is to scale the distributed cloud to the 10,000-core level, with the ability to run any type of application (low I/O, high I/O and high memory) on any cloud. To achieve this goal, we have been implementing changes that utilize context-aware computing designs that are currently employed in the mobile communication industry. Context-awareness makes use of real-time and archived data to respond to user or system requirements. In our distributed cloud, we have many opportunistic clouds with no local HEP services, software or storage repositories. A context-aware design significantly improves the reliability and performance of our system by locating the nearest location of the required services. We describe how we are collecting and managing contextual information from our workload management systems, the clouds, the virtual machines and our services. This information is used not only to monitor the system but also to carry out automated corrective actions. We are incrementally adding new alerting and response services to our distributed cloud. This will enable us to scale the number of clouds and virtual machines. Further, a context-aware design will enable us to run analysis or high I/O application on opportunistic clouds. We envisage an open-source HTTP data federation (for example, the DynaFed system at CERN) as a service that would provide us access to existing storage elements used by the HEP experiments.

AceCloud: Molecular Dynamics Simulations in the Cloud.

Science.gov (United States)

Harvey, M J; De Fabritiis, G

2015-05-26

We present AceCloud, an on-demand service for molecular dynamics simulations. AceCloud is designed to facilitate the secure execution of large ensembles of simulations on an external cloud computing service (currently Amazon Web Services). The AceCloud client, integrated into the ACEMD molecular dynamics package, provides an easy-to-use interface that abstracts all aspects of interaction with the cloud services. This gives the user the experience that all simulations are running on their local machine, minimizing the learning curve typically associated with the transition to using high performance computing services.

VMware private cloud computing with vCloud director

CERN Document Server

Gallagher, Simon

2013-01-01

It's All About Delivering Service with vCloud Director Empowered by virtualization, companies are not just moving into the cloud, they're moving into private clouds for greater security, flexibility, and cost savings. However, this move involves more than just infrastructure. It also represents a different business model and a new way to provide services. In this detailed book, VMware vExpert Simon Gallagher makes sense of private cloud computing for IT administrators. From basic cloud theory and strategies for adoption to practical implementation, he covers all the issues. You'll lea

The response of filamentary and spherical clouds to the turbulence and magnetic field

Science.gov (United States)

Gholipour, Mahmoud

2018-05-01

Recent observations have revealed that there is a power-law relation between magnetic field and density in molecular clouds. Furthermore, turbulence has been observed in some regions of molecular clouds and the velocity dispersion resulting from the turbulence is found to correlate with to the cloud density. Relating to these observations, in this study, we model filamentary and spherical clouds in magnetohydrostatic equilibrium in two quiescent and turbulent regions. The proposed equations are expected to represent the impact of magnetic field and turbulence on the cloud structure and the relation of cloud mass with shape. The Virial theorem is applied to consider the cloud evolution leading to important conditions for equilibrium of the cloud over its lifetime. The obtained results indicate that under the same conditions of the magnetic field and turbulence, each shape presents different responses. The possible ways for the formation of massive cores or coreless clouds in some regions as well as the formation of massive stars or low-mass stars can be discussed based on the results of this study. It should be mentioned that the shape of the clouds plays an important role in the formation of the protostellar clouds as well as their structure and evolution. This role is due to the effects of magnetic fields and turbulence.

IS THE DUST CLOUD AROUND LAMBDA ORIONIS A RING OR A SHELL, OR BOTH?

Energy Technology Data Exchange (ETDEWEB)

Lee, Dukhang; Seon, Kwang-Il; Jo, Young-Soo, E-mail: lee.dukhang@gmail.com [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)

2015-06-20

The dust cloud around λ Orionis is observed to be circularly symmetric with a large angular extent (≈8°). However, whether the three-dimensional (3D) structure of the cloud is shell- or ring-like has not yet been fully resolved. We study the 3D structure using a new approach that combines a 3D Monte Carlo radiative transfer model for ultraviolet (UV) scattered light and an inverse Abel transform, which gives a detailed 3D radial density profile from a two-dimensional column density map of a spherically symmetric cloud. By comparing the radiative transfer models for a spherical shell cloud and that for a ring cloud, we find that only the shell model can reproduce the radial profile of the scattered UV light, observed using the S2/68 UV observation, suggesting a dust shell structure. However, the inverse Abel transform applied to the column density data from the Pan-STARRS1 dust reddening map results in negative values at a certain radius range of the density profile, indicating the existence of additional, non-spherical clouds near the nebular boundary. The additional cloud component is assumed to be of toroidal ring shape; we subtracted from the column density to obtain a positive, radial density profile using the inverse Abel transform. The resulting density structure, composed of a toroidal ring and a spherical shell, is also found to give a good fit to the UV scattered light profile. We therefore conclude that the cloud around λ Ori is composed of both ring and shell structures.

A Broker Framework for Secure and Cost-Effective Business Process Deployment on Multiple Clouds

OpenAIRE

Goettelmann , Elio; Dahman , Karim; Gateau , Benjamin; Godart , Claude

2014-01-01

International audience; Security risk management on information systems provides security guarantees while controlling costs. But security risk assessments can be very complex, especially in a cloud context where data is dis-tributed over multiple environments. To prevent costs from becoming the only cloud selection factor, while disregarding security, we propose a method for performing multiple cloud security risk assessments. In this paper we present a broker framework for balancing costs a...

Buildings and Terrain of Urban Area Point Cloud Segmentation based on PCL

International Nuclear Information System (INIS)

Liu, Ying; Zhong, Ruofei

2014-01-01

One current problem with laser radar point data classification is building and urban terrain segmentation, this paper proposes a point cloud segmentation method base on PCL libraries. PCL is a large cross-platform open source C++ programming library, which implements a large number of point cloud related efficient data structures and generic algorithms involving point cloud retrieval, filtering, segmentation, registration, feature extraction and curved surface reconstruction, visualization, etc. Due to laser radar point cloud characteristics with large amount of data, unsymmetrical distribution, this paper proposes using the data structure of kd-tree to organize data; then using Voxel Grid filter for point cloud resampling, namely to reduce the amount of point cloud data, and at the same time keep the point cloud shape characteristic; use PCL Segmentation Module, we use a Euclidean Cluster Extraction class with Europe clustering for buildings and ground three-dimensional point cloud segmentation. The experimental results show that this method avoids the multiple copy system existing data needs, saves the program storage space through the call of PCL library method and class, shortens the program compiled time and improves the running speed of the program

The impact of horizontal heterogeneities, cloud fraction, and cloud dynamics on warm cloud effective radii and liquid water path from CERES-like Aqua MODIS retrievals

Science.gov (United States)

Painemal, D.; Minnis, P.; Sun-Mack, S.

2013-05-01

The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES Edition 4 algorithms are averaged at the CERES footprint resolution (~ 20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8 - re2.1 differences are positive ( 50 g m-2, and negative (up to -4 μm) for larger Hσ. Thus, re3.8 - re2.1 differences are more likely to reflect biases associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

The Research of Dr. Joanne Simpson: Fifty Years Investigating Hurricanes, Tropical Clouds and Cloud Systems

Science.gov (United States)

Tao, W. -K.; Halverson, J.; Adler, R.; Garstang, M.; Houze, R., Jr.; LeMone, M.; Pielke, R., Sr.; Woodley, W.; O'C.Starr, David (Technical Monitor)

2001-01-01

This AMS Meteorological Monographs is dedicated to Dr. Joanne Simpson for her many pioneering research efforts in tropical meteorology during her fifty-year career. Dr. Simpson's major areas of scientific research involved the "hot tower" hypothesis and its role in hurricanes, structure and maintenance of trade winds, air-sea interaction, and observations and the mechanism for hurricanes and waterspouts. She was also a pioneer in cloud modeling with the first one-dimensional model and had the first cumulus model on a computer. She also played a major role in planning and leading observational experiments on convective cloud systems. The launch of the Tropical Rainfall Measuring Mission (TRMM) satellite, a joint U.S.-Japan project, in November of 1997 made it possible for quantitative measurements of tropical rainfall to be obtained on a continuous basis over the entire global tropics. Dr. Simpson was the TRAM Project Scientist from 1986 until its launch in 1997. Her efforts during this crucial period ensured that the mission was both well planned scientifically and well engineered as well as within budget. In this paper, Dr. J. Simpson's nine specific accomplishments during her fifty-year career: (1) hot tower hypothesis, (2) hurricanes, (3) airflow and clouds over heated islands, (4) cloud models, (5) trade winds and their role in cumulus development, (6) air-sea interaction, (7) cloud-cloud interactions and mergers, (8) waterspouts, and (9) TRMM science, will be described and discussed.

Sedimentation Efficiency of Condensation Clouds in Substellar Atmospheres

Science.gov (United States)

Gao, Peter; Marley, Mark S.; Ackerman, Andrew S.

2018-03-01

Condensation clouds in substellar atmospheres have been widely inferred from spectra and photometric variability. Up until now, their horizontally averaged vertical distribution and mean particle size have been largely characterized using models, one of which is the eddy diffusion–sedimentation model from Ackerman and Marley that relies on a sedimentation efficiency parameter, f sed, to determine the vertical extent of clouds in the atmosphere. However, the physical processes controlling the vertical structure of clouds in substellar atmospheres are not well understood. In this work, we derive trends in f sed across a large range of eddy diffusivities (K zz ), gravities, material properties, and cloud formation pathways by fitting cloud distributions calculated by a more detailed cloud microphysics model. We find that f sed is dependent on K zz , but not gravity, when K zz is held constant. f sed is most sensitive to the nucleation rate of cloud particles, as determined by material properties like surface energy and molecular weight. High surface energy materials form fewer, larger cloud particles, leading to large f sed (>1), and vice versa for materials with low surface energy. For cloud formation via heterogeneous nucleation, f sed is sensitive to the condensation nuclei flux and radius, connecting cloud formation in substellar atmospheres to the objects’ formation environments and other atmospheric aerosols. These insights could lead to improved cloud models that help us better understand substellar atmospheres. For example, we demonstrate that f sed could increase with increasing cloud base depth in an atmosphere, shedding light on the nature of the brown dwarf L/T transition.

Evaluation of cloud properties in the NOAA/NCEP global forecast system using multiple satellite products

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hyelim [University of Maryland, Department of Atmospheric and Oceanic Science, College Park, MD (United States); Li, Zhanqing [University of Maryland, Department of Atmospheric and Oceanic Science, College Park, MD (United States); Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resource Ecology, GCESS, Beijing (China)

2012-12-15

Knowledge of cloud properties and their vertical structure is important for meteorological studies due to their impact on both the Earth's radiation budget and adiabatic heating within the atmosphere. The objective of this study is to evaluate bulk cloud properties and vertical distribution simulated by the US National Oceanic and Atmospheric Administration National Centers for Environmental Prediction Global Forecast System (GFS) using three global satellite products. Cloud variables evaluated include the occurrence and fraction of clouds in up to three layers, cloud optical depth, liquid water path, and ice water path. Cloud vertical structure data are retrieved from both active (CloudSat/CALIPSO) and passive sensors and are subsequently compared with GFS model results. In general, the GFS model captures the spatial patterns of hydrometeors reasonably well and follows the general features seen in satellite measurements, but large discrepancies exist in low-level cloud properties. More boundary layer clouds over the interior continents were generated by the GFS model whereas satellite retrievals showed more low-level clouds over oceans. Although the frequencies of global multi-layer clouds from observations are similar to those from the model, latitudinal variations show discrepancies in terms of structure and pattern. The modeled cloud optical depth over storm track region and subtropical region is less than that from the passive sensor and is overestimated for deep convective clouds. The distributions of ice water path (IWP) agree better with satellite observations than do liquid water path (LWP) distributions. Discrepancies in LWP/IWP distributions between observations and the model are attributed to differences in cloud water mixing ratio and mean relative humidity fields, which are major control variables determining the formation of clouds. (orig.)

Creating cloud-free Landsat ETM+ data sets in tropical landscapes: cloud and cloud-shadow removal

Science.gov (United States)

Sebastián Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez

2007-01-01

Clouds and cloud shadows are common features of visible and infrared remotelysensed images collected from many parts of the world, particularly in humid and tropical regions. We have developed a simple and semiautomated method to mask clouds and shadows in Landsat ETM+ imagery, and have developed a recent cloud-free composite of multitemporal images for Puerto Rico and...

The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin Australia)

Energy Technology Data Exchange (ETDEWEB)

May, Peter T.; Long, Charles N.; Protat, Alain

2012-08-01

The diurnal variation of convection and associated cloud and radiative properties remains a significant issue in global NWP and climate models. This study analyzes observed diurnal variability of convection in a coastal monsoonal environment examining the interaction of convective rain clouds, their associated cloud properties, and the impact on the surface radiation and corresponding boundary layer structure during periods where convection is suppressed or active on the large scale. The analysis uses data from the Tropical Warm Pool International Cloud Experiment (TWP-ICE) as well as routine measurements from the Australian Bureau of Meteorology and the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. Both active monsoonal and large-scale suppressed (buildup and break) conditions are examined and demonstrate that the diurnal variation of rainfall is much larger during the break periods and the spatial distribution of rainfall is very different between the monsoon and break regimes. During the active monsoon the total net radiative input to the surface is decreased by more than 3 times the amount than during the break regime - this total radiative cloud forcing is found to be dominated by the shortwave (SW) cloud effects because of the much larger optical thicknesses and persistence of long-lasting anvils and cirrus cloud decks associated with the monsoon regime. These differences in monsoon versus break surface radiative energy contribute to low-level air temperature differences in the boundary layer over the land surfaces.

The structure and origin of magnetic clouds in the solar wind

Directory of Open Access Journals (Sweden)

V. Bothmer

Full Text Available Plasma and magnetic field data from the Helios 1/2 spacecraft have been used to investigate the structure of magnetic clouds (MCs in the inner heliosphere. 46 MCs were identified in the Helios data for the period 1974–1981 between 0.3 and 1 AU. 85% of the MCs were associated with fast-forward interplanetary shock waves, supporting the close association between MCs and SMEs (solar mass ejections. Seven MCs were identified as direct consequences of Helios-directed SMEs, and the passage of MCs agreed with that of interplanetary plasma clouds (IPCs identified as white-light brightness enhancements in the Helios photometer data. The total (plasma and magnetic field pressure in MCs was higher and the plasma-β lower than in the surrounding solar wind. Minimum variance analysis (MVA showed that MCs can best be described as large-scale quasi-cylindrical magnetic flux tubes. The axes of the flux tubes usually had a small inclination to the ecliptic plane, with their azimuthal direction close to the east-west direction. The large-scale flux tube model for MCs was validated by the analysis of multi-spacecraft observations. MCs were observed over a range of up to ~60° in solar longitude in the ecliptic having the same magnetic configuration. The Helios observations further showed that over-expansion is a common feature of MCs. From a combined study of Helios, Voyager and IMP data we found that the radial diameter of MCs increases between 0.3 and 4.2 AU proportional to the distance, R, from the Sun as R^0.8 (R in AU. The density decrease inside MCs was found to be proportional to R^–2.4, thus being stronger compared to the average solar wind. Four different magnetic configurations, as expected from the flux-tube concept, for MCs have been observed in situ by the Helios probes. MCs with left- and right-handed magnetic helicity occurred with about equal frequencies during 1974–1981, but surprisingly, the majority (74% of the MCs had

3D And 4D Cloud Lifecycle Investigations Using Innovative Scanning Radar Analysis Methods. Final report

Energy Technology Data Exchange (ETDEWEB)

Kollias, Pavlos [Stony Brook Univ., NY (United States)

2017-04-23

With the vast upgrades to the ARM program radar measurement capabilities in 2010 and beyond, our ability to probe the 3D structure of clouds and associated precipitation has increased dramatically. This project build on the PI's and co-I's expertisein the analysis of radar observations. The first research thrust aims to document the 3D morphological (as depicted by the radar reflectivity structure) and 3D dynamical (cloud$-$scale eddies) structure of boundary layer clouds. Unraveling the 3D dynamical structure of stratocumulus and shallow cumulus clouds requires decomposition of the environmental wind contribution and particle sedimentation velocity from the observed radial Doppler velocity. The second thrust proposes to unravel the mechanism of cumulus entrainment (location, scales) and its impact on microphysics utilizing radar measurements from the vertically pointing and new scanning radars at the ARM sites. The third research thrust requires the development of a cloud$-$tracking algorithm that monitors the properties of cloud.

International Space Science Institute Workshop on Shallow Clouds, Water Vapor, Circulation and Climate Sensitivity

CERN Document Server

Winker, David; Bony, Sandrine; Stevens, Bjorn

2018-01-01

This volume presents a series of overview articles arising from a workshop exploring the links among shallow clouds, water vapor, circulation, and climate sensitivity. It provides a state-of-the art synthesis of understanding about the coupling of clouds and water vapor to the large-scale circulation. The emphasis is on two phenomena, namely the self-aggregation of deep convection and interactions between low clouds and the large-scale environment, with direct links to the sensitivity of climate to radiative perturbations. Each subject is approached using simulations, observations, and synthesizing theory; particular attention is paid to opportunities offered by new remote-sensing technologies, some still prospective. The collection provides a thorough grounding in topics representing one of the World Climate Research Program’s Grand Challenges. Previously published in Surveys in Geophysics, Volume 38, Issue 6, 2017 The articles “Observing Convective Aggregation”, “An Observational View of Relationshi...

Discrete Optimization of Internal Part Structure via SLM Unit Structure-Performance Database

Directory of Open Access Journals (Sweden)

Li Tang

2018-01-01

Full Text Available The structural optimization of the internal structure of parts based on three-dimensional (3D printing has been recognized as being important in the field of mechanical design. The purpose of this paper is to present a creation of a unit structure-performance database based on the selective laser melting (SLM, which contains various structural units with different functions and records their structure and performance characteristics so that we can optimize the internal structure of parts directly, according to the database. The method of creating the unit structure-performance database was introduced in this paper and several structural units of the unit structure-performance database were introduced. The bow structure unit was used to show how to create the structure-performance database of the unit as an example. Some samples of the bow structure unit were designed and manufactured by SLM. These samples were tested in the WDW-100 compression testing machine to obtain their performance characteristics. After this, the paper collected all data regarding unit structure parameters, weight, performance characteristics, and other data; and, established a complete set of data from the bow structure unit for the unit structure-performance database. Furthermore, an aircraft part was reconstructed conveniently to be more lightweight according to the unit structure-performance database. Its weight was reduced by 36.8% when compared with the original structure, while the strength far exceeded the requirements.

Zen of cloud learning cloud computing by examples on Microsoft Azure

CERN Document Server

Bai, Haishi

2014-01-01

Zen of Cloud: Learning Cloud Computing by Examples on Microsoft Azure provides comprehensive coverage of the essential theories behind cloud computing and the Windows Azure cloud platform. Sharing the author's insights gained while working at Microsoft's headquarters, it presents nearly 70 end-to-end examples with step-by-step guidance on implementing typical cloud-based scenarios.The book is organized into four sections: cloud service fundamentals, cloud solutions, devices and cloud, and system integration and project management. Each chapter contains detailed exercises that provide readers w

Photometric Metallicities of the Small and Large Magellanic Clouds

Science.gov (United States)

Miller, Amy Elizabeth

2018-06-01

In the field of astronomy, the study of galaxies is vitally important to understanding the structure and evolution of the universe. Within the study of galaxies, of particular interest are the Small and Large Magellanic Clouds (SMC and LMC, respectively), two of the Milky Way’s closest and most massive satellite galaxies. Their close proximity make them ideal candidates for understanding astrophysical processes such as galaxy interactions. In order to fully understand the Magellanic Clouds, it is imperative that the metallicity of the clouds be mapped in detail. In order to accomplish this task, I will use data from the Survey of Magellanic Stellar History (SMASH) which is a deep, multi-band (ugriz) photometric survey of the Magellanic Clouds that contains approximately 400 million objects in 197 fully-calibrated fields. SMASH is an extensive and deep photometric data set that enables the full-scale study of the galactic structure in the Clouds. The SMASH u-band is sensitive to metallicity for main-sequence turn-off stars which we calibrate using SDSS spectroscopy in overlapping regions (mainly standard star fields). The final steps will be to make metallicity maps of the main bodies and peripheries of the LMC and SMC. Ultimately, these metallicity maps will help us trace out population gradients in the Clouds and uncover the origin of their very extended stellar peripheries.

TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Gao, Yang; Law, Chung K.; Xu, Haitao

2015-01-01

The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation

COMPARATIVE STUDY OF CLOUD COMPUTING AND MOBILE CLOUD COMPUTING

OpenAIRE

Nidhi Rajak*, Diwakar Shukla

2018-01-01

Present era is of Information and Communication Technology (ICT) and there are number of researches are going on Cloud Computing and Mobile Cloud Computing such security issues, data management, load balancing and so on. Cloud computing provides the services to the end user over Internet and the primary objectives of this computing are resource sharing and pooling among the end users. Mobile Cloud Computing is a combination of Cloud Computing and Mobile Computing. Here, data is stored in...

The Clouds distributed operating system - Functional description, implementation details and related work

Science.gov (United States)

Dasgupta, Partha; Leblanc, Richard J., Jr.; Appelbe, William F.

1988-01-01

Clouds is an operating system in a novel class of distributed operating systems providing the integration, reliability, and structure that makes a distributed system usable. Clouds is designed to run on a set of general purpose computers that are connected via a medium-of-high speed local area network. The system structuring paradigm chosen for the Clouds operating system, after substantial research, is an object/thread model. All instances of services, programs and data in Clouds are encapsulated in objects. The concept of persistent objects does away with the need for file systems, and replaces it with a more powerful concept, namely the object system. The facilities in Clouds include integration of resources through location transparency; support for various types of atomic operations, including conventional transactions; advanced support for achieving fault tolerance; and provisions for dynamic reconfiguration.

Review of Cloud Computing and existing Frameworks for Cloud adoption

OpenAIRE

Chang, Victor; Walters, Robert John; Wills, Gary

2014-01-01

This paper presents a selected review for Cloud Computing and explains the benefits and risks of adopting Cloud Computing in a business environment. Although all the risks identified may be associated with two major Cloud adoption challenges, a framework is required to support organisations as they begin to use Cloud and minimise risks of Cloud adoption. Eleven Cloud Computing frameworks are investigated and a comparison of their strengths and limitations is made; the result of the comparison...

Self-force as probe of internal structure

International Nuclear Information System (INIS)

Isoyama, Soichiro; Poisson, Eric

2012-01-01

The self-force acting on a (scalar or electric) charge held in place outside a massive body contains information about the body's composition, and can therefore be used as a probe of internal structure. We explore this theme by computing the (scalar or electromagnetic) self-force when the body is a spherical ball of perfect fluid in hydrostatic equilibrium, under the assumption that its rest-mass density and pressure are related by a polytropic equation of state. The body is strongly self-gravitating, and all computations are performed in exact general relativity. The dependence on internal structure is best revealed by expanding the self-force in powers of r -1 0 , with r 0 denoting the radial position of the charge outside the body. To the leading order, the self-force scales as r -3 0 and depends only on the square of the charge and the body's mass; the leading self-force is universal. The dependence on internal structure is seen at the next order, r -5 0 , through a structure factor that depends on the equation of state. We compute this structure factor for relativistic polytropes, and show that for a fixed mass, it increases linearly with the body's radius in the case of the scalar self-force, and quadratically with the body's radius in the case of the electromagnetic self-force. In both cases we find that for a fixed mass and radius, the self-force is smaller if the body is more centrally dense, and larger if the mass density is more uniformly distributed. (paper)

INDICATORS FOR CLUSTER SURVIVABILITY IN A DISPERSING CLOUD

International Nuclear Information System (INIS)

Chen, H.-C.; Ko, C.-M.

2009-01-01

We use N-body simulations to survey the response of embedded star clusters to the dispersal of their parent molecular cloud. The final stages of the clusters can be divided into three classes: the cluster (1) is destroyed, (2) has a loose structure, and (3) has a compact core. We are interested in three of the governing parameters of the parent cloud: (1) the mass, (2) the size, and (3) the dispersing rate. It is known that the final stage of the cluster is well correlated with the star formation efficiency (SFE) for systems with the same cluster and cloud profile. We deem that the SFE alone is not enough to address systems with clouds of different sizes. Our result shows that the initial cluster-cloud mass ratio at a certain Lagrangian radius and the initial kinetic energy are better indicators for the survivability of embedded clusters.

Turbulent Cloud Structure and Power Spectrum from 23 years of HST Observations

Science.gov (United States)

Cosentino, Richard; Simon, Amy; Morales-Juberias, Raul

2018-01-01

Images of Jupiter’s clouds show that turbulence is a ubiquitous phenomenon over many orders of scale size. According to Kolmogorov’s theory for turbulence, the frequency/distribution of clouds at various scales can be used to produce an energy power spectrum of a passive tracer. Kolmogorov theory predicts the spectral slopes for “shallow” and “deep” fluids in motion by following how energy is injected and dissipated in the fluid. We are quantifying the turbulent nature of Jupiter’s clouds over 23 years of Hubble Space Telescope (HST) observations using an algorithm first presented in Choi and Showman (2011, Icarus 216). We applied the power spectrum fitting algorithm to a variety of filters from available HST data and tested its sensitivity to free parameters and compare our results to Choi and Showman (2011). We will comment on the evidence for a 2D turbulent regime In Jupiter’s clouds and will report on empirical values found in the spectra and their physical interpretations, such as the Rhines scale. We also will report on the behavior of the passive tracer power spectrum and trends that exist over time for different latitudinal regions, primarily the belts and zones and the north and south equatorial belts.

Modelling of internal structure in seismic analysis of a PHWR building

International Nuclear Information System (INIS)

Reddy, G.R.; Vaze, K.K.; Kushawaha, H.S.; Ingle, R.K.; Subramanian, K.V.

1991-01-01

Seismic analysis of complex and large structures, consisting of thick shear walls, such as Reactor Building is very involved and time consuming. It is a standard practice to model the structure as a stick model to predict reasonably the dynamic behaviour of the structure. It is required to determine approximate equivalent sectional properties of Internal Structure for representation in the stick model. The restraint to warping can change the stress distribution thus affecting the centre of rigidity and torsional inertia, Hence, standard formulae does not hold good for determination of sectional properties of the Internal Structure. In this case the equivalent sectional properties for the Internal Structure are calculated using a Finite Element Model (FEM) of the Internal Structure and applying unit horizontal forces in each direction. A 3-D stick model is developed using the guidelines. Using the properties calculated by FEM and also by standard formulae, the responses of the 3-D stick model are compared. (J.P.N.)

Cloud CCN feedback

International Nuclear Information System (INIS)

Hudson, J.G.

1992-01-01

Cloud microphysics affects cloud albedo precipitation efficiency and the extent of cloud feedback in response to global warming. Compared to other cloud parameters, microphysics is unique in its large range of variability and the fact that much of the variability is anthropogenic. Probably the most important determinant of cloud microphysics is the spectra of cloud condensation nuclei (CCN) which display considerable variability and have a large anthropogenic component. When analyzed in combination three field observation projects display the interrelationship between CCN and cloud microphysics. CCN were measured with the Desert Research Institute (DRI) instantaneous CCN spectrometer. Cloud microphysical measurements were obtained with the National Center for Atmospheric Research Lockheed Electra. Since CCN and cloud microphysics each affect the other a positive feedback mechanism can result

International Good Market Segmentation and Financial Market Structure

OpenAIRE

Basak, Suleyman; Croitoru, Benjamin

2003-01-01

While financial markets have recently become more complete and international capital flows well liberalized, markets for goods remain segmented. To investigate how more complete security markets may relieve the effects of this segmentation, we examine a series of two-country economies with internationally segmented good markets, distinguished by the available financial securities. We show that, under heterogeneity within countries, the financial structure matters: even with internationally co...

Considerations about Cloud Services: Learning

Directory of Open Access Journals (Sweden)

Riccardo Cognini

2013-05-01

Full Text Available Cloud services are ubiquitous: for small to large companies the phenomenon of cloud service is nowadays a standard business practice. This paper would compile an analysis over a possible implementation of a cloud system, treating especially the legal aspect of this theme. In the Italian market has a large number of issues arise form cloud computing. First of all, this paper investigates the legal issues associated to cloud computing, specific contractual scheme that is able to define rights a duties both of user (private and/or public body and cloud provider. On one side there is all the EU legislative production related to privacy over electronic communication and, furthermore, the Privacy Directive is under a revision process to be more adaptable to new challenges of decentralized data treatment, but concretely there are no any structured and well defined legal instruments. Objectives: we present a possible solution to address the uncertainty of this area, starting from the EU legislative production with the help of the specific Italian scenario that could offer an operative solution. Indeed the Italian legal system is particularly adaptable to changing technologies and it could use as better as possible to adapt the already existing legal tools to this new technological era. Prior work: after an introduction to the state of the art, we show the main issues and their critical points that must be solved. Approach: observation of the state of the art to propose a new approach to find the suitable disciple

PROCESSING UAV AND LIDAR POINT CLOUDS IN GRASS GIS

Directory of Open Access Journals (Sweden)

V. Petras

2016-06-01

Full Text Available Today’s methods of acquiring Earth surface data, namely lidar and unmanned aerial vehicle (UAV imagery, non-selectively collect or generate large amounts of points. Point clouds from different sources vary in their properties such as number of returns, density, or quality. We present a set of tools with applications for different types of points clouds obtained by a lidar scanner, structure from motion technique (SfM, and a low-cost 3D scanner. To take advantage of the vertical structure of multiple return lidar point clouds, we demonstrate tools to process them using 3D raster techniques which allow, for example, the development of custom vegetation classification methods. Dense point clouds obtained from UAV imagery, often containing redundant points, can be decimated using various techniques before further processing. We implemented and compared several decimation techniques in regard to their performance and the final digital surface model (DSM. Finally, we will describe the processing of a point cloud from a low-cost 3D scanner, namely Microsoft Kinect, and its application for interaction with physical models. All the presented tools are open source and integrated in GRASS GIS, a multi-purpose open source GIS with remote sensing capabilities. The tools integrate with other open source projects, specifically Point Data Abstraction Library (PDAL, Point Cloud Library (PCL, and OpenKinect libfreenect2 library to benefit from the open source point cloud ecosystem. The implementation in GRASS GIS ensures long term maintenance and reproducibility by the scientific community but also by the original authors themselves.

Big data mining analysis method based on cloud computing

Science.gov (United States)

Cai, Qing Qiu; Cui, Hong Gang; Tang, Hao

2017-08-01

Information explosion era, large data super-large, discrete and non-(semi) structured features have gone far beyond the traditional data management can carry the scope of the way. With the arrival of the cloud computing era, cloud computing provides a new technical way to analyze the massive data mining, which can effectively solve the problem that the traditional data mining method cannot adapt to massive data mining. This paper introduces the meaning and characteristics of cloud computing, analyzes the advantages of using cloud computing technology to realize data mining, designs the mining algorithm of association rules based on MapReduce parallel processing architecture, and carries out the experimental verification. The algorithm of parallel association rule mining based on cloud computing platform can greatly improve the execution speed of data mining.

Atomic carbon in an infrared dark cloud

NARCIS (Netherlands)

Ossenkopf, Volker; Ormel, Chris W.; Simon, Robert; Sun, Kefeng; Stutzki, Jürgen

2010-01-01

Infrared dark clouds (IRDCs) are potential sites of massive star formation, dark in the near-infrared, but in many cases already with indications of active star-formation from far-infrared and submm observations. They are an ideal test bed to study the role of internal and external heating on the

Formaldehyde in the Diffuse Interstellar Cloud MBM40

Science.gov (United States)

Joy, Mackenzie; Magnani, Loris A.

2018-06-01

MBM40, a high-latitude molecular cloud, has been extensively studied using different molecular tracers. It appears that MBM40 is composed of a relatively dense, helical filament embedded in a more diffuse substrate of low density molecular gas. In order to study the transition between the two regimes, this project presents the first high-resolution mapping of MBM40 using the 110-111 hyperfine transition of formaldehyde (H2CO) at 4.83 GHz. We used H2CO spectra obtained with the Arecibo telescope more than a decade ago to construct this map. The results can be compared to previous maps made from the CO(1-0) transition to gain further understanding of the structure of the cloud. The intensity of the H2CO emission was compared to the CO emission. Although a correlation exists between the H2CO and CO emissivity, there seems to be a saturation of H2CO line strength for stronger CO emissivity. This is probably a radiative transfer effect of the CO emission. We have also found that the velocity dispersion of H2CO in the lower ridge of the cloud is significantly lower than in the rest of the cloud. This may indicate that this portion of the cloud is a coherent structure (analogous to an eddy) in a turbulent flow.

Cloud Governance

DEFF Research Database (Denmark)

Berthing, Hans Henrik

Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing.......Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing....

Carbon Isotope Chemistry in Molecular Clouds

Science.gov (United States)

Robertson, Amy N.; Willacy, Karen

2012-01-01

Few details of carbon isotope chemistry are known, especially the chemical processes that occur in astronomical environments like molecular clouds. Observational evidence shows that the C-12/C-13 abundance ratios vary due to the location of the C-13 atom within the molecular structure. The different abundances are a result of the diverse formation pathways that can occur. Modeling can be used to explore the production pathways of carbon molecules in an effort to understand and explain the chemical evolution of molecular clouds.

Recommendation for Mitigations of the Electron Cloud Instability in the ILC

International Nuclear Information System (INIS)

Pivi, Mauro

2011-01-01

Electron cloud has been identified as one of the highest priority issues for the international Linear Collider (ILC) Damping Rings (DR). An electron cloud Working Group (WG) has evaluated the electron cloud effect and instability, and mitigation solutions for the electron cloud formation. Working group deliverables include recommendations for the baseline and alternate solutions to the electron cloud formation in various regions of the ILC Positron DR, which is presently assumed to be the 3.2 km design. Detailed studies of a range of mitigation options including coatings, clearing electrodes, grooves and novel concepts, were carried out over the previous several years by nearly 50 researchers, and the results of the studies form the basis for the recommendation. The recommendations are the result of the working group discussions held at numerous meetings and during a dedicated workshop. In addition, a number of items requiring further investigation were identified during the discussions at the Cornell meeting and studies will be carried out at CesrTA, a test accelerator dedicated to electron cloud studies, and other institutions.

An Examination of the Nature of Global MODIS Cloud Regimes

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji; Huffman, George J.

2014-01-01

We introduce global cloud regimes (previously also referred to as "weather states") derived from cloud retrievals that use measurements by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua and Terra satellites. The regimes are obtained by applying clustering analysis on joint histograms of retrieved cloud top pressure and cloud optical thickness. By employing a compositing approach on data sets from satellites and other sources, we examine regime structural and thermodynamical characteristics. We establish that the MODIS cloud regimes tend to form in distinct dynamical and thermodynamical environments and have diverse profiles of cloud fraction and water content. When compositing radiative fluxes from the Clouds and the Earth's Radiant Energy System instrument and surface precipitation from the Global Precipitation Climatology Project, we find that regimes with a radiative warming effect on the atmosphere also produce the largest implied latent heat. Taken as a whole, the results of the study corroborate the usefulness of the cloud regime concept, reaffirm the fundamental nature of the regimes as appropriate building blocks for cloud system classification, clarify their association with standard cloud types, and underscore their distinct radiative and hydrological signatures.

Black carbon semi-direct effects on cloud cover: review and synthesis

Directory of Open Access Journals (Sweden)

D. Koch

2010-08-01

Full Text Available Absorbing aerosols (AAs such as black carbon (BC or dust absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. Previous studies have described conditions under which AAs either increase or decrease cloud cover. The effect depends on several factors, including the altitude of the AA relative to the cloud and the cloud type. We attempt to categorize the effects into several likely regimes. Cloud cover is decreased if the AAs are embedded in the cloud layer. AAs below cloud may enhance convection and cloud cover. AAs above cloud top stabilize the underlying layer and tend to enhance stratocumulus clouds but may reduce cumulus clouds. AAs can also promote cloud cover in convergent regions as they enhance deep convection and low level convergence as it draws in moisture from ocean to land regions. Most global model studies indicate a regional variation in the cloud response but generally increased cloud cover over oceans and some land regions, with net increased low-level and/or reduced upper level cloud cover. The result is a net negative semi-direct effect feedback from the cloud response to AAs. In some of these climate model studies, the cooling effect of BC due to cloud changes is strong enough to essentially cancel the warming direct effects.

The effect of finite geometry on the three-dimensional transfer of solar irradiance in clouds

Science.gov (United States)

Davies, R.

1978-01-01

Results are presented for a Monte Carlo model applied to a wide range of cloud widths and heights, and for an analytical model restricted in its application to cuboidally shaped clouds whose length, breadth, and depth may be varied independently; the clouds must be internally homogeneous with respect to their intrinsic radiative properties. Comparative results from the Monte Carlo method and the derived analytical model are presented for a wide range of cloud sizes, with special emphasis on the effects of varying the single scatter albedo, the solar zenith angle, and the scattering phase angle.

An Automatic Cloud Detection Method for ZY-3 Satellite

Directory of Open Access Journals (Sweden)

CHEN Zhenwei

2015-03-01

Full Text Available Automatic cloud detection for optical satellite remote sensing images is a significant step in the production system of satellite products. For the browse images cataloged by ZY-3 satellite, the tree discriminate structure is adopted to carry out cloud detection. The image was divided into sub-images and their features were extracted to perform classification between clouds and grounds. However, due to the high complexity of clouds and surfaces and the low resolution of browse images, the traditional classification algorithms based on image features are of great limitations. In view of the problem, a prior enhancement processing to original sub-images before classification was put forward in this paper to widen the texture difference between clouds and surfaces. Afterwards, with the secondary moment and first difference of the images, the feature vectors were extended in multi-scale space, and then the cloud proportion in the image was estimated through comprehensive analysis. The presented cloud detection algorithm has already been applied to the ZY-3 application system project, and the practical experiment results indicate that this algorithm is capable of promoting the accuracy of cloud detection significantly.

Comparisons of Satellite-Deduced Overlapping Cloud Properties and CALIPSO CloudSat Data

Science.gov (United States)

Chang, Fu-Lung; Minnis, Patrick; Lin, Bing; Sun-Mack, Sunny

2010-01-01

Introduction to the overlapped cloud properties derived from polar-orbiting (MODIS) and geostationary (GOES-12, -13, Meteosat-8, -9, etc.) meteorological satellites, which are produced at the NASA Langley Research Center (LaRC) cloud research & development team (NASA lead scientist: Dr. Patrick Minnis). Comparison of the LaRC CERES MODIS Edition-3 overlapped cloud properties to the CALIPSO and the CloudSat active sensing data. High clouds and overlapped clouds occur frequently as deduced by CALIPSO (44 & 25%), CloudSat (25 & 4%), and MODIS (37 & 6%). Large fractions of optically-thin cirrus and overlapped clouds are deduced from CALIPSO, but much smaller fractions are from CloudSat and MODIS. For overlapped clouds, the averaged upper-layer CTHs are about 12.8 (CALIPSO), 10.9 (CloudSat) and 10 km (MODIS), and the averaged lower-layer CTHs are about 3.6 (CALIPSO), 3.2 (CloudSat) and 3.9 km (MODIS). Based on comparisons of upper and lower-layer cloud properties as deduced from the MODIS, CALIPSO and CloudSat data, more enhanced passive satellite methods for retrieving thin cirrus and overlapped cloud properties are needed and are under development.

Polarized View of Supercooled Liquid Water Clouds

Science.gov (United States)

Alexandrov, Mikhail D.; Cairns, Brian; Van Diedenhoven, Bastiaan; Ackerman, Andrew S.; Wasilewski, Andrzej P.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Platnick, Steven E.; Arnold, G. Thomas

2016-01-01

Supercooled liquid water (SLW) clouds, where liquid droplets exist at temperatures below 0 C present a well known aviation hazard through aircraft icing, in which SLW accretes on the airframe. SLW clouds are common over the Southern Ocean, and climate-induced changes in their occurrence is thought to constitute a strong cloud feedback on global climate. The two recent NASA field campaigns POlarimeter Definition EXperiment (PODEX, based in Palmdale, California, January-February 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, based in Houston, Texas in August- September 2013) provided a unique opportunity to observe SLW clouds from the high-altitude airborne platform of NASA's ER-2 aircraft. We present an analysis of measurements made by the Research Scanning Polarimeter (RSP) during these experiments accompanied by correlative retrievals from other sensors. The RSP measures both polarized and total reflectance in 9 spectral channels with wavelengths ranging from 410 to 2250 nm. It is a scanning sensor taking samples at 0.8deg intervals within 60deg from nadir in both forward and backward directions. This unique angular resolution allows for characterization of liquid water droplet size using the rainbow structure observed in the polarized reflectances in the scattering angle range between 135deg and 165deg. Simple parametric fitting algorithms applied to the polarized reflectance provide retrievals of the droplet effective radius and variance assuming a prescribed size distribution shape (gamma distribution). In addition to this, we use a non-parametric method, Rainbow Fourier Transform (RFT),which allows retrieval of the droplet size distribution without assuming a size distribution shape. We present an overview of the RSP campaign datasets available from the NASA GISS website, as well as two detailed examples of the retrievals. In these case studies we focus on cloud fields with spatial features

Securing the Cloud Cloud Computer Security Techniques and Tactics

CERN Document Server

Winkler, Vic (JR)

2011-01-01

As companies turn to cloud computing technology to streamline and save money, security is a fundamental concern. Loss of certain control and lack of trust make this transition difficult unless you know how to handle it. Securing the Cloud discusses making the move to the cloud while securing your peice of it! The cloud offers felxibility, adaptability, scalability, and in the case of security-resilience. This book details the strengths and weaknesses of securing your company's information with different cloud approaches. Attacks can focus on your infrastructure, communications network, data, o

Waves on the surface of the Orion molecular cloud.

Science.gov (United States)

Berné, Olivier; Marcelino, Núria; Cernicharo, José

2010-08-19

Massive stars influence their parental molecular cloud, and it has long been suspected that the development of hydrodynamical instabilities can compress or fragment the cloud. Identifying such instabilities has proved difficult. It has been suggested that elongated structures (such as the 'pillars of creation') and other shapes arise because of instabilities, but alternative explanations are available. One key signature of an instability is a wave-like structure in the gas, which has hitherto not been seen. Here we report the presence of 'waves' at the surface of the Orion molecular cloud near where massive stars are forming. The waves seem to be a Kelvin-Helmholtz instability that arises during the expansion of the nebula as gas heated and ionized by massive stars is blown over pre-existing molecular gas.

Hybrid Cloud Computing Environment for EarthCube and Geoscience Community

Science.gov (United States)

Yang, C. P.; Qin, H.

2016-12-01

The NSF EarthCube Integration and Test Environment (ECITE) has built a hybrid cloud computing environment to provides cloud resources from private cloud environments by using cloud system software - OpenStack and Eucalyptus, and also manages public cloud - Amazon Web Service that allow resource synchronizing and bursting between private and public cloud. On ECITE hybrid cloud platform, EarthCube and geoscience community can deploy and manage the applications by using base virtual machine images or customized virtual machines, analyze big datasets by using virtual clusters, and real-time monitor the virtual resource usage on the cloud. Currently, a number of EarthCube projects have deployed or started migrating their projects to this platform, such as CHORDS, BCube, CINERGI, OntoSoft, and some other EarthCube building blocks. To accomplish the deployment or migration, administrator of ECITE hybrid cloud platform prepares the specific needs (e.g. images, port numbers, usable cloud capacity, etc.) of each project in advance base on the communications between ECITE and participant projects, and then the scientists or IT technicians in those projects launch one or multiple virtual machines, access the virtual machine(s) to set up computing environment if need be, and migrate their codes, documents or data without caring about the heterogeneity in structure and operations among different cloud platforms.

Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions

Energy Technology Data Exchange (ETDEWEB)

McFarquhar, Greg [Univ. of Illinois, Urbana, IL (United States)

2015-12-28

We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol’s influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects.In this report we describe the accomplishments that we made on all 3 research objectives.

Cloud management and security

CERN Document Server

Abbadi, Imad M

2014-01-01

Written by an expert with over 15 years' experience in the field, this book establishes the foundations of Cloud computing, building an in-depth and diverse understanding of the technologies behind Cloud computing. In this book, the author begins with an introduction to Cloud computing, presenting fundamental concepts such as analyzing Cloud definitions, Cloud evolution, Cloud services, Cloud deployment types and highlighting the main challenges. Following on from the introduction, the book is divided into three parts: Cloud management, Cloud security, and practical examples. Part one presents the main components constituting the Cloud and federated Cloud infrastructure(e.g., interactions and deployment), discusses management platforms (resources and services), identifies and analyzes the main properties of the Cloud infrastructure, and presents Cloud automated management services: virtual and application resource management services. Part two analyzes the problem of establishing trustworthy Cloud, discuss...

Reconstruction of 3D Shapes of Opaque Cumulus Clouds from Airborne Multiangle Imaging: A Proof-of-Concept

Science.gov (United States)

Davis, A. B.; Bal, G.; Chen, J.

2015-12-01

Operational remote sensing of microphysical and optical cloud properties is invariably predicated on the assumption of plane-parallel slab geometry for the targeted cloud. The sole benefit of this often-questionable assumption about the cloud is that it leads to one-dimensional (1D) radiative transfer (RT)---a textbook, computationally tractable model. We present new results as evidence that, thanks to converging advances in 3D RT, inverse problem theory, algorithm implementation, and computer hardware, we are at the dawn of a new era in cloud remote sensing where we can finally go beyond the plane-parallel paradigm. Granted, the plane-parallel/1D RT assumption is reasonable for spatially extended stratiform cloud layers, as well as the smoothly distributed background aerosol layers. However, these 1D RT-friendly scenarios exclude cases that are critically important for climate physics. 1D RT---whence operational cloud remote sensing---fails catastrophically for cumuliform clouds that have fully 3D outer shapes and internal structures driven by shallow or deep convection. For these situations, the first order of business in a robust characterization by remote sensing is to abandon the slab geometry framework and determine the 3D geometry of the cloud, as a first step toward bone fide 3D cloud tomography. With this specific goal in mind, we deliver a proof-of-concept for an entirely new kind of remote sensing applicable to 3D clouds. It is based on highly simplified 3D RT and exploits multi-angular suites of cloud images at high spatial resolution. Airborne sensors like AirMSPI readily acquire such data. The key element of the reconstruction algorithm is a sophisticated solution of the nonlinear inverse problem via linearization of the forward model and an iteration scheme supported, where necessary, by adaptive regularization. Currently, the demo uses a 2D setting to show how either vertical profiles or horizontal slices of the cloud can be accurately reconstructed

Methodology for cloud-based design of robots

Science.gov (United States)

Ogorodnikova, O. M.; Vaganov, K. A.; Putimtsev, I. D.

2017-09-01

This paper presents some important results for cloud-based designing a robot arm by a group of students. Methodology for the cloud-based design was developed and used to initiate interdisciplinary project about research and development of a specific manipulator. The whole project data files were hosted by Ural Federal University data center. The 3D (three-dimensional) model of the robot arm was created using Siemens PLM software (Product Lifecycle Management) and structured as a complex mechatronics product by means of Siemens Teamcenter thin client; all processes were performed in the clouds. The robot arm was designed in purpose to load blanks up to 1 kg into the work space of the milling machine for performing student's researches.

On the mechanism of Venusian atmosphere cloud layer formation

International Nuclear Information System (INIS)

Zhulanov, Yu.V.; Mukhin, L.M.; Nenarokov, D.F.

1987-01-01

Results of investigations into the aerosol component of Venusian atmosphere using a photoelectric counter in the 63-47 km range of heights at the Vega-1 and Vega-2 interplanetary stations are presented. The experiment was carried out in June, 11, 15, 1985 on the night-time side of the planet. Both devices were switched in at the height of 63 km, and data on the quantity of detected particles >=0.5 μm in diameter were transmitted every 0.43 s (that corresponds to 8-20 m spatial resolution). Study of particle concentration profiles obtained at the interval of 4 days (one period of rotation of Venusian atmosphere) permits to make the following conclusions on the structure of Venusian atmosphere cloud layer on the night side: 1) the cloud layer includes two distinct cloud strata: the upper- 56-60 km height range and the lower- 49.5-46.5 km height range separated by the zone of low particle concentrations ( -3 ); 2) the mentioned structure of the cloud layer is rather stable; concentration profiles obtained at the interval of 4 days well agree with each other; 3) concentration profiles, particularly, in the lower cloud-stratum are subjected to heavy fluctuations, that indicates essential spatial field heterogeneity of particle concentrations

Precipitation-generated oscillations in open cellular cloud fields.

Science.gov (United States)

Feingold, Graham; Koren, Ilan; Wang, Hailong; Xue, Huiwen; Brewer, Wm Alan

2010-08-12

Cloud fields adopt many different patterns that can have a profound effect on the amount of sunlight reflected back to space, with important implications for the Earth's climate. These cloud patterns can be observed in satellite images of the Earth and often exhibit distinct cell-like structures associated with organized convection at scales of tens of kilometres. Recent evidence has shown that atmospheric aerosol particles-through their influence on precipitation formation-help to determine whether cloud fields take on closed (more reflective) or open (less reflective) cellular patterns. The physical mechanisms controlling the formation and evolution of these cells, however, are still poorly understood, limiting our ability to simulate realistically the effects of clouds on global reflectance. Here we use satellite imagery and numerical models to show how precipitating clouds produce an open cellular cloud pattern that oscillates between different, weakly stable states. The oscillations are a result of precipitation causing downward motion and outflow from clouds that were previously positively buoyant. The evaporating precipitation drives air down to the Earth's surface, where it diverges and collides with the outflows of neighbouring precipitating cells. These colliding outflows form surface convergence zones and new cloud formation. In turn, the newly formed clouds produce precipitation and new colliding outflow patterns that are displaced from the previous ones. As successive cycles of this kind unfold, convergence zones alternate with divergence zones and new cloud patterns emerge to replace old ones. The result is an oscillating, self-organized system with a characteristic cell size and precipitation frequency.

Military clouds: utilization of cloud computing systems at the battlefield

Science.gov (United States)

Süleyman, Sarıkürk; Volkan, Karaca; İbrahim, Kocaman; Ahmet, Şirzai

2012-05-01

Cloud computing is known as a novel information technology (IT) concept, which involves facilitated and rapid access to networks, servers, data saving media, applications and services via Internet with minimum hardware requirements. Use of information systems and technologies at the battlefield is not new. Information superiority is a force multiplier and is crucial to mission success. Recent advances in information systems and technologies provide new means to decision makers and users in order to gain information superiority. These developments in information technologies lead to a new term, which is known as network centric capability. Similar to network centric capable systems, cloud computing systems are operational today. In the near future extensive use of military clouds at the battlefield is predicted. Integrating cloud computing logic to network centric applications will increase the flexibility, cost-effectiveness, efficiency and accessibility of network-centric capabilities. In this paper, cloud computing and network centric capability concepts are defined. Some commercial cloud computing products and applications are mentioned. Network centric capable applications are covered. Cloud computing supported battlefield applications are analyzed. The effects of cloud computing systems on network centric capability and on the information domain in future warfare are discussed. Battlefield opportunities and novelties which might be introduced to network centric capability by cloud computing systems are researched. The role of military clouds in future warfare is proposed in this paper. It was concluded that military clouds will be indispensible components of the future battlefield. Military clouds have the potential of improving network centric capabilities, increasing situational awareness at the battlefield and facilitating the settlement of information superiority.