Cloud Zones Research Articles

Accelerated Verifiable Fair Digital Exchange

A Fair Digital Exchange is defined as either all or none of the participants achieving a (predetermined) desirable outcome. This work addresses third party mediated systems for digital content where mutually unknown, and hence non-trusting, buyers, sellers and the mediator (third party) take part in an exchange protocol. We address the lack of guaranteed fairness, as defined above, in the existing platforms for this setting. We present TEDX, a decentralized solution for guaranteed three party fair exchange of digital goods with scalability and support for incremental deployment over the existing (non-fair) platforms. TEDX combines carefully crafted message exchanges with incentive schemes designed to deter malicious behavior. TEDX also leverages ideas from blockchain anchored state-channels to provide trusted execution while minimizing the operational overheads of blockchain. We present the design and a security analysis of TEDX to validate the claimed fairness properties. We also present the details of a prototype implementation of TEDX leveraging Hyperledger Fabric and performance evaluation of the same on a realistic testbed spanning five public cloud zones. Our results indicate that TEDX adds only a minimal overhead of 16% while being 46x faster than a naive blockchain solution, thereby demonstrating that TEDX is scalable.

Entrainment rates in the cloud zones of continental shallow cumulus

Entrainment rates from in situ measurements and Large Eddy simulations (LES) of shallow clouds over the Indian peninsula are presented in this study. It is noted that the coherent motions of counter-rotating vortices originate from the updraft zones within clouds, and they subside around shallow clouds. Clouds with stronger updrafts gain depth and have high liquid water content near the cloud top. A three-parameter clustering algorithm (K means) identifies the subregions of the cloud from its core to the surrounding subsiding region. The extreme core region has the highest liquid water content, droplet number concentration, updrafts, and minimum entrainment rates. The varying degree of dilution in the cloud zones is identified here, featuring the dynamics associated with the moist adiabat. Parametric relationships between the entrainment rate and buoyancy in the different cloud zones are illustrated, which could be useful in large-scale models.

Predictive BPaaS management with quantum and neural computing

AbstractWith the increasing adoption of cloud computing, the deployment and management of business processes over cloud environments have become an essential operation for most enterprises, leading to the emergence of BPaaS (Business Process as a Service) as a new cloud service model. This SaaS‐like service, like its ancestors, should be strategically distributed and managed over multiple cloud zones, while taking into account several constraints and conditions (e.g., sensitivity of BPaaS fragments, insecure and untrusted cloud zones, lack of resources, and workload changes). However, current BPaaS approaches are static, which means that they are no longer suitable to manage such enterprise‐oriented cloud service model and to deal with the uncertain and dynamic nature of cloud availability zones. To fill this gap, we adopt a predictive BPaaS management strategy by proposing a model that forecasts the next‐short time overload of cloud zones. These latter, as hosting environments for the managed BPaaS, are categorized as overloaded or underloaded, which triggers the migration of BPaaS fragments to high‐performance cloud zones. The proposed neural network prediction model (called QGA‐NN) is enhanced with a quantum genetic algorithm to optimize the prediction of cloud zones' overload. QGA‐NN is evaluated using a BPaaS placement algorithm, which we defined as a triggered management operation. Experimental results have proved the accuracy and effectiveness of our predictive approach, compared with state‐of‐the‐art solutions.

Bringing semantics to multicloud service compositions

SummaryOver the last decade, cloud computing has emerged as a new paradigm for delivering various on‐demand virtualized resources as services. Cloud services have inherited not only the major characteristics of web services but also their classical issues, in particular, the interoperability issues and the heterogeneous nature of their hosting environments. This latter problem must be taken into account when composing various cloud services, in order to answer users' complex requirements. Moreover, leading cloud providers started to offer their services across multiple clouds. This adds a new factor of heterogeneity, as composition engines must take into consideration the heterogeneity not only at the service level (eg, service descriptions) but also at the cloud level (eg, pricing models, security policies). In this context, the semantics of multicloud actors must be incorporated into the multicloud service composition (MCSC) process. However, most existing approaches have treated the semantic service composition in traditional single‐cloud environments. The few works in multicloud settings have ignored the semantics of cloud zones and resources. Moreover, they often focus on the general aspect of MCSC (eg, horizontal or vertical compositions). Even the few researchers who have addressed both vertical and horizontal service compositions, conducted their research studies in the context of single‐ cloud environments, which were proven to be unrealistic and offer limited quality of service (QoS) and security support. To ensure a high interoperability when composing services from multiple heterogeneous clouds and to enable a horizontal/vertical semantic service compositions, we take advantage of a standardized and semantically enriched generic service description, including all aspects (technical, operational, business, semantic, contextual) and supporting different cloud service models (SaaS, PaaS, IaaS, etc). We also incorporate Semantic Web Rule Language into the MCSC process to enable not only rule‐based reasoning about various composition constraints (eg, QoS constraints, cloud zones constraints) but also to provide accurate semantic matching of cloud services' capabilities. Conducted experiments have proven the ability of our approach to combine high‐quality services from the optimal number of clouds.

Hydrocarbon accumulation conditions and key exploration and development technologies for PL 19–3 oilfield

The PL 19–3 Oilfield is the only super-large monolithic oilfield with oil and gas reserves up to 1 × 109 t in the Bohai Bay Basin, and it has been successfully developed. Exploration and development practices have provided abundant data for analyzing formation conditions of this super-large oilfield. On the basis of the exploration and development history, fundamental reservoir features, and with available geological, geophysical and test data, the hydrocarbon accumulation conditions and key exploration & development technologies of the PL 19–3 Oilfield were discussed. The key conditions for forming the super-large Neogene oilfield include four aspects. Firstly, the oilfield is located at the high position of the uplift that contacts the brachy-axis of the multi-ridge slope in the biggest hydrocarbon-rich sag in the Bohai Bay Basin, thus it has sufficient hydrocarbon source and extremely superior hydrocarbon migration condition. Secondly, the large-scale torsional anticlines which formed in the Neogene under the control of the Tanlu strike-slipping movement provide sufficient storage spaces for oil and gas preservation. Thirdly, the “multiple sets of composite reservoir-caprock assemblages” developing in the special shallow-water delta further contributes greatly to the effective storage space for oil and gas preservation. Fourthly, due to the coupling of the uplift and strike slip in the neotectonic period, extensive faulting activities constantly released the pressure while the late period massive hydrocarbon expulsion of the Bozhong took place at the same time, which assures the constant and intense charging of oil and gas. The super-large PL 19–3 Oilfield was controlled by the coupling effects of all those special geologic factors. In view of this oilfield's features (e.g. violently reformation caused by strike slip, and the special sedimentary environment of shallow-water delta), some key practical technologies for exploration and development have been developed. Such technologies include: the special prestack depth migration processing for gas cloud zones, the prediction of thin interbed reservoirs based on high-precision inversion of geologic model, the reservoir description for the shallow-water braided river delta, the quantitative description for remaining oil in the commingled oil reservoirs with wide well spacing and long well interval, and the well pattern adjustment for formations during high water cut period in the complex fluvial-facies oilfields.

Online Auction of Cloud Resources in Support of the Internet of Things

Internet of Things (IoT) applications can benefit greatly from cloud-hosted message broker services that utilize publish–subscribe communications. The operators of IoT cloud-hosted services are often interested in delivering services that maximize their revenue given quality of service guarantees. In this paper, we formulate the problem of maximizing the profit of the service provider given the prior knowledge of the request sequence as an integer linear program and prove that it is strongly NP-complete, and thus there is no fully polynomial-time approximation scheme for the problem, unless ${P=} \text {NP}$ . Due to the above-mentioned problem and the difficulty of obtaining the request sequence in advance in real-world scenarios, we propose an auction-based online algorithm that does not require the prior knowledge of the request sequence. We prove that the competitive ratio of the online algorithm is ${\mathcal {O}(\log (N))}$ , where ${N}$ is the number of cloud zones that host the publish–subscribe services. Moreover, we show that no online algorithm can achieve a competitive ratio better than ${\Omega (\log (N))}$ . Therefore, our online algorithm achieves the optimal competitive ratio in the asymptotic sense. Our simulations, based on real data traces, show that our algorithm achieves up to 83% more profit compared to a heuristic approach, while consuming 60% less resources.

겨울철 동해상의 대상수렴운과 그 주위의 대류운에 관한 WRF 수치모의 연구

This study analyzed atmospheric conditions for the convergent cloud band (Cu-Cb line) in developing stage and its neighbouring convections formed over the East Sea on 1 February 2012, by using synoptic, satellites data, and WRF numerical simulation output of high resolution. In both satellite images and the WRF numerical simulation outputs, the Cu-Cb line that stretched out toward northwest-southeast was shown in the East Sea, and cloud lines of the L mode were aligned in accordance with the prevailing surface wind direction. However, those of the T mode were aligned in the direction of NE-SW, which was nearly perpendicular direction to the surface winds. The directions of the wind shear vectors connecting top winds and bottom winds of the moist layers of the L mode and the T mode were identical with those of the cloud lines of L mode and T mode, respectively. From the WRF simulation convection circulations with a convergence in the lower layer of atmosphere and a divergence above 1.5 km ASL (Above Sea Level) were identified in the Cu-Cb line. A series of small sized vortexes (maximum vortex: <TEX>$320{\times}10^{-5}s^{-1}$</TEX>) of meso-<TEX>${\gamma}$</TEX>-scale formed by convergences was found along the Cu-Cb lines, suggesting that Cu-Cb lines, consisting of numerous convective clouds, were closely associated with a series of the small vortexes. There was an absolute unstable layer (<TEX>${\partial}{\theta}/{\partial}z$</TEX> < 0) between sfc and ~0.3 km ASL, and a stable layer (<TEX>${\partial}{\theta}/{\partial}z$</TEX> > 0) above ~2 km ASL over the Cu-Cb line and cloud zones. Not only convectively unstable layers (<TEX>${\partial}{\theta}_e/{\partial}z$</TEX> < 0) but also neutral layers (<TEX>${\partial}{\theta}_e/{\partial}z{\approx}=0$</TEX>) in the lower atmosphere (sfc~1.5 km ASL) were scattered around over the cloud zones. Particularly, for the Cu-Cb line there were convectively unstable layers in the surface layer, and neutral layers (<TEX>${\partial}{\theta}_e/{\partial}z{\approx}=0$</TEX>) between 0.2 and ~1.5 km ASL over near the center of the Cu-Cb line, and the neutralization of unstable layers came from the release of convective instability.

Cloud water content effects on computing spectral characteristics of temperature fields and turbulent heat fluxes in the cumulus cloud zones as derived from airborne observations

Analyzed are the earlier obtained data on the dynamic structure of cumulus (convective) clouds in order to estimate cloud water content effects on the air temperature, computed turbulent fluxes, and their spectral characteristics. It is demonstrated that the cloud and precipitation droplets falling to the aircraft temperature sensor provoke an error in temperature measurements. Developed is a method for taking into account these effects and for computing the correct air temperature fluctuations in the cloud, wavelet spectra of the temperature, and wavelet cospectra of heat fluxes. The use of the method enabled to construct a consistent picture of horizontal heat flux distribution in the cumulus zone depending on the wave number and cloud location. It is shown that mesoscale eddies with the scale of more than 500 m are the main factors of heat exchange between clouds and the ambient space, and the role of turbulence consists only in the mixing inside the cloud. The conclusion is made that the temperature adjustment to the water content of the cloud is needed for correct interpretation of the results of aircraft observations of dynamic structure of cumulus clouds.

Algorithm for Removing Thick Clouds in TM Image Based on Spectral and Geometric Information

A new cloud removal algorithm based on spectral and geometric information is proposed for generating cloud free and cloud-shadow free mosaic image from multi-temporal TM images.At first,single image and multi-temporal images of thick cloud and cloud-shadow multi-spectral detection models are built based on TM spectral characteristics analysis.Secondly,cloud is detected according to spectral characteristics,and then a technique is applied based on coupled geometrical relationship between the cloud and its shadow by using sun azimuth angle,sun elevation angle and statistical distance between cloud and its shadow so as to automatically predict the approximate location of cloud-shadow.After that,erosion filtering and dilation filtering are used sequentially in the cloud and cloud-shadow fraction image to eliminate the small bits and generate the exact zones contaminated by cloud and cloud-shadow.At last,the cloud and cloud-shadow zones of the target image are replaced by the same-location cloud-free zones on reference images whose spectral information is matched with the target image by the linear regression method.The results show that this algorithm is capable of eliminating the cloud influence from TM image significantly.Moreover,it can effectively eliminate the influence of water body and hill shadow on cloud-shadow.This method can therefore support producing cloud removal images in a quick,simple and applicable way.

Multiple Frontal Structures in the Baiu Frontal Zone Observed by Aircraft on 27 June 2004

The structure of the Baiu frontal zone over the East China Sea on 27 June 2004 was investigated using data from aircraft observations. During the period of 09-12 JST (Japanese Standard Time: UTC + 9 hours), three cloud zones appeared over the East China Sea. The Baiu frontal zone is conveniently divided into three zones on the basis of the three cloud zones. The zones on the southern side, in the middle, and on the northern side are called FZ1, FZ2, and FZ3, respectively. The position of FZ2 corresponded with that of a stationary front on the surface weather map. Remarkable variations of winds, potential temperature, and moisture corresponding to the three zones were detected using in situ measurements at 500 m MSL (Mean Sea Level). In FZ1, a decreased southerly wind area associated with a remarkable moisture gradient was seen, although the potential temperature gradient was unclear. FZ2 had remarkable gradients of potential temperature and moisture associated with a drastic change from southwesterly to northwesterly winds. FZ3 also had remarkable gradients of potential temperature and moisture. This study shows observational evidence of the fact that multiple frontal structures exist inside the Baiu frontal zone.

The Digital Archive of the Photographic Images of the Córdoba Observatory Plates Collections

The astronomical events registered in photographic plates are unique. A remarkable interest in using old plates in many areas of the current astronomical research is widely recognized by the IAU. There are almost ten thousand plates in several collections at the Cordoba Observatory and most of them are nearly one century old. This photographic material is difficult to handle in order to get the information stored in it. The goal of this project is to make a digital archive of images of these collections. In this first survey plates are being scanned with a standard commercial transparency scanner. These low spatial resolution, low digital resolution and low signal-to-noise ratio images are intended for facilitating handling and visual inspection. However, one arc-second positions can be obtained. Photometric quality has not been yet determined. Otherwise high quality digital images can be acquired with a microdenstitometer based on a scientific grade CCD whose implementation is at its final stage. The possibility of using a better-performance scanner is being evaluated. It is planned to permit the access to low-resolution images via internet. High-resolution images of selected zones will be available upon request. At this first stage, collections totally digitized at low resolution are:Carte du Ciel and Small Magellanic Cloud Zones. Gaviola's Eta Carinae Spectra and Pulkovo Zones are still in process.

Sulfur and oxygen isotope studies of melt-country rock interaction, Babbitt Cu-Ni deposit, Duluth Complex, Minnesota

The Babbitt Cu-Ni deposit, formerly known as Minnamax, occurs within troctolitic and gabbroic rocks of the Precambrian Duluth Complex. Both massive and disseminated mineralizations are found in the deposit. Pyrrhotite, cubanite, chalcopyrite, and minor pentlandite mineralization occurs near the basal contact with pelitic metasedimentary rocks of the Virginia Formation or higher in the igneous sequence associated with abundant country-rock xenoliths (cloud zones). Sulfur and oxygen isotope studies have been carried out to evaluate the importance of melt-country rock interaction in localizing sulfide mineralization.The delta 34 S values of pyrrhotite plus pyrite from the Virginia Formation located outside the contact aureole range from 5.6 to 13.7 per mil. Pyrrhotite from footwall Virginia Formation hornfels or inclusions in the basal zone exhibits delta 34 S values ranging from 1.5 to 6.2 per mil, whereas delta 34 S values of pyrrhotite from xenoliths in cloud zones range from 2.6 to 21.4 per mil. Isotopic values of basal zone Cu-Ni sulfides range from 6.0 to 13.0 per mil, with a mode at 8 to 9 per mil. Two features highlight basal zone delta 34 S values. First, delta 34 S values of sulfide mineralization are higher than those of pyrrhotite in immediately adjacent Virginia Formation hornfels. Second, higher grade ore areas (> 1% Cu) show 34 S enrichment, with delta 34 S values in the range of 9 to 13 per mil. Sulfides in cloud zones show a wide range in delta 34 S values, from 0.7 to 19.7 per mil. Sulfur isotope data suggest that most of the sulfur found in the deposit has been derived from sedimentary country rocks. However, an in situ process of sulfur derivation is not indicated. Sulfur in basal mineralized zones must have been derived at depth within an auxiliary magma chamber or during magma ascent and emplacement. Isotopic homogenization was not achieved during the sulfide-forming process as evidenced by the spatial variability of delta 34 S values.Oxygen isotope values of both mildly metamorphosed Virginia Formation and footwall hornfels range from 8.2 to 14.0 per mil. Inclusions of Virginia Formation show pronounced isotopic effects due to interaction with melt. Xenolith margins may have values as low as 7 to 8 per mil and are depleted in 18 O with respect to xenolith interiors. The delta 18 O values of igneous rocks from the Babbitt deposit range from 3.9 to 12.2 per mil. Zones of 18 O depletion are rare and suggest that exchange with a low 18 O fluid phase was spatially restricted. Anomalous delta 18 O values in excess of 7 to 7.5 per mil are common throughout the deposit but are limited to within 3 m of Virginia Formation xenoliths. A model of diffusion-controlled 18 exchange between igneous material and xenoliths best describes the delta 18 O distribution. Devolatilization and desilicification of the xenoliths occurred early in their history, when physical mixing in the host magma was possible. Addition of high 18 O material from these processes into a large volume of melt affected delta 18 O distributions only slightly. Continued exchange of oxygen after major cation transfer produced the observed delta 18 O profiles.In the case of basal zone Cu-Ni mineralization at Babbitt, isotopic evidence indicates that sulfide saturation was not caused by in situ addition of sulfur, silica, or oxygen. Sulfide saturation is thought to have been achieved at depth, triggered by assimilation of large quantities of sulfide liberated through devolatilization reactions occurring in country rocks.

Infrared observations of Jupiter cloud zones

Images of Jupiter have been obtained at three wavelengths intervals in the infrared: 0.7–2.5, 1.2–1.3, and 1.5–1.7 μm. The inages show evidence for two distinct zones of high-altitude clouds, one at 10° north latitude, the other at 22° south. The cloud zones also appear to be at different heights in the atmosphere and to have particles with different scattering properties.