Cloud Patterns Research Articles

A Multi-Class Based Algorithm for Finding Relevant Usage Patterns from Infrequent Patterns of Large Complex Data

Background/Objective: With the development of data mining techniques to analyze large amount of complex data has played an essential role in several areas like cloud computing, medical databases, geographical information retrieval, etc. The automatic evaluation of cloud patterns is a challenging task due to the large amount of interesting patterns can be extracted. However, how to find infrequent patterns is still an open issue in cloud computing. Methods: Conventional approaches are mainly depends on quantitative datasets with support and confidence measures. Due to the large amount of cloud storage data, it is very difficult to extract the weighted association rules based on the server usage statistics. Traditional techniques are implemented on the data samples with the same attribute type. Due to this fact, a multi-class algorithm is proposed to find relevant usage patterns of large complex data. Findings: Proposed approach does not rely on any probabilistic closure measures and quantitative data. This approach minimizes the database scans and optimizes the infrequent cloud patterns. Applications/Improvements: Experimental results show that, proposed work generates high quality cloud patterns compared to traditional quantitative rule mining techniques.

AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS

Abstract. The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (𝜎𝜃) and vertical (𝜎𝛼) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as 𝜎𝜃=±36.6𝑐𝑐 and 𝜎𝛼=±17.8𝑐𝑐, respectively. On the other hand, a priori precision of the range observation (𝜎𝜌) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as 𝜎𝜌=±2−12 𝑚𝑚 for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.

AN EMPRICAL POINT ERROR MODEL FOR TLS DERIVED POINT CLOUDS

The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (𝜎<sub>𝜃</sub>) and vertical (𝜎<sub>𝛼</sub>) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as 𝜎<sub>𝜃</sub>=±36.6<sup>𝑐𝑐</sup> and 𝜎<sub>𝛼</sub>=±17.8<sup>𝑐𝑐</sup>, respectively. On the other hand, a priori precision of the range observation (𝜎<sub>𝜌</sub>) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as 𝜎<sub>𝜌</sub>=±2−12 𝑚𝑚 for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.

Mesoscale convective systems in association with tropical cyclones over Bay of Bengal

The early stages of tropical cyclones (TCs) are extremely complex, and their understanding presents a challenge to researchers worldwide. Better understanding of the role of mesoscale convective systems (MCS) in the formative stage of TC will increase the ability to predict their characteristics including intensification and movement. Objective of the study is to analyze the interaction of multiple mesoscale structures during different stages of TC. In this study, Kalpana-1 half-hourly satellite infrared imageries are used to observe the interaction between MCSs and their environment. Average areas of MCS are calculated based on different cloud top temperatures (CTTs) viz −30, −50, −70 °C and also for different stages of TC based on five TCs during 2010–2012. The analysis has been carried out with respect to variations of (1) number of clusters, (2) distance between the clusters, (3) average distance of clusters from the center of the TC, and (4) area of clusters with respect to intensity (T number) of TC. Results indicate that merger of mesoscale convective vortices is a common precursor event during TC genesis. The average distances between clusters almost remain same during genesis and growing phase, and it gradually decreases during mature phase of TC. Further, there is decrease in the average distance of cloud clusters from the center of TC with respect to increase in intensity up to 2.5–3.5 after that the distance decreases with increase in intensity as the cloud pattern changes to central dense overcast or eye pattern. The average areas of the clusters associated the cyclonic disturbances increases from genesis phase till the intensity reaches T3.0; thereafter, it decreases gradually with increase in intensity. The number of clusters, the distances between them and their average distances from the center of the disturbance, and the total area of clusters show diurnal variations which is more significant during initial stage of formation. The study will be helpful in better understanding of physical processes in diurnal variations of convection and relation between convection and intensity of the storm.

Numerical Simulation of Unsteady Cavitation in a High-speed Water Jet

Abstract Concerning the numerical simulation of high-speed water jet with intensive cavitation this paper presents a practical compressible mixture flow method by coupling a simplified estimation of bubble cavitation and a compressible mixture flow computation. The mean flow of two-phase mixture is calculated by RANS for compressible fluidU he intensit. T y of cavitation in a local field is evaluated by the volume fraction of gas phase varying with the mean flow, and the effect of cavitation on the flow turbulence is considered by applying a ion to density correctthe evaluation of eddy viscosity. High-speed submerged water jets issuing from a sheathed sharp-edge orifice nozzle are treated when the cavitation number, σ = 0.1, and the computation result is compared with experimental data The result reveals that cavitation occurs initially at the entrance of orifice and bubble cloud develops gradually while flowing downstream along the shear layer. Developed bubble cloudbreaks up and then sheds downstream periodically near the sheath exit. The pattern of cavitation cloud shedding evaluated by simulation agrees experimental one, and the possibility to capture the unsteadily shedding of cavitation clouds is demonstrated. The decay of core velocity in cavitating jetis delayed greatly compared to that in no-activation jet, and the effect of the nozzle sheath is demonstrated.

Historical Research on Costume for Boy Court Dancers for Restoration of Yeongseongje

The study contains the results of historical research on costume for boy court dancers worn in restoration performance Yeongseongje that King Jeongjo intended to recover in National Gugak Center in 2015, in addition to related components. Yeongseongje refers to commemorative rites for Yeongseong, the God of Agriculture. Yeongseongje was abolished during the era of King Jungjong before being discussed again in the era of King Jeongjo. In an effort to restore Yeongseongje, King Jeongjo built Seongdanhyangui. Originally, music and dance were not used in Yeongseongje, and King Jeongjo used popular music (sogak) and had 16 boy dancers in the court dance. Since there are no records of the costume the boy dancers wore in court, the costume was designed based on historical materials. In order to select a costume for the boy dancers in court, six main concepts such as ‘performance’, ‘budget’, ‘ancestral ritual formalities’, ‘trends of the times’, ‘military music’ and ‘yuk-jeon’ were extracted. Based on these concepts, Cheolrik was selected as the most appropriate costume. The appropriateness of cheolrik as a costume for boy court dancers for Yeongseongje was confirmed based on the perception of cheolrik in the era of King Jeongjo, ‘Seonyurak’, where cheolrik was used in court dance, and an examination of ‘Goguryeo’ dance. In terms of the components of costume for boy court dancers for Yeongseongje, the Goguryeo dance costume was deemed to be more appropriate than the Seonyurak dance costume. For this reason, Goguryeo dance costume was partially altered and used. Heukrip, which is similar to those prepared by the National Center for Korean Traditional Performing Arts, was used. As for cheolrik, navy silk with cloud patterns was used in consideration of the lighting and the dance routine. In terms of the shape of cheolrik, Ik-jeong Lee(1699-1782)’s cheolrik was consulted for the purpose of production. In addition, a grey durumagi(traditional Korean overcoat), Honggwangdae, Heukhye and pale blue-green Haengjeon were manufactured.

How can Periodic Workload Cloud Pattern benefit from Periodically Peaking Utilization?

How can Periodic Workload Cloud Pattern benefit from Periodically Peaking Utilization?

The Pacific Written Tradition

The Pacific Written Tradition Craig Santos Perez (bio) In 2010, I read aloud from my new bookto an English class at one of Guam’spublic high schools. After the reading, I notice a student crying. “Whats wrong?”I ask. She says, “I’ve never seen our culturein a book before. I just thought we weren’t worthy of literature.” I wonder how manyyoung islanders have dived into the depthsof a book, only to find bleached coral and emptiness. They teach us that missionarieswere the first readers in the Pacific becausethey could decipher the strange signs of the Bible. They teach us that missionarieswere the first authors in the Pacific becausethey possessed the authority of written words. Today, studies show that islander students readand write below grade level. “It’s natural,”they claim. “Your ancestors were an illiterate, oral people.” Do not believe their claims.Our ancestors deciphered signs in nature,interpreted star formations and sun positions, cloud and wind patterns, wave currents andfish migrations. Always remember what navigatorPapa Mau once said: “if you can read the ocean you will never be lost.” Now let me tell youabout the Pacific written tradition, about howour ancestors tattooed their skin with defiant scripts of intricately inked genealogy, storiesof plumage and pain. Or how our ancestors carvedepics into hard wood with a sharpened point, [End Page 110] their hands, and the pressure and responsibilityof memory. Or how our ancestors stenciledhieroglyphic poems on cave walls with clay, fire, and smoke. So the next time someone tells youislanders were illiterate, teach themabout our visual literacies, about how we still read and write the intertextual sacrednessof all things. And always remember: if youcan write the ocean we will never be silenced. [End Page 111] Craig Santos Perez Craig Santos Perez is a native Chamorro from the Pacific Island of Guam. He is the author of three books, most recently from unincorporated territory [guma'], which received an American Book Award 2015. He is an associate professor in the English department at the University of Hawai'i, Manoa. Copyright © 2016 University of Wisconsin Board of Regents

Emerging Hybrid Cloud Patterns

The hybrid cloud model provides the best of the private and public worlds, combining the economies and efficiencies of public cloud computing with the security and control of private cloud computing. However, marrying public and private cloud services requires advanced thinking and some handy technology.

Atmospheric Kármán Vortex Shedding from Jeju Island, East China Sea: A Numerical Study*

Abstract A mesoscale atmospheric numerical model is used to simulate two cases of Kármán vortex shedding in the lee of Jeju Island, South Korea, in the winter of 2013. Observed cloud patterns associated with the Kármán vortex shedding are successfully reproduced. When the winter monsoon flows out from the Eurasian continent, a convective mixed layer develops through the supply of heat and moisture from the relatively warm Yellow Sea and encounters Jeju Island and dynamical conditions favorable for the formation of lee vortices are realized. Vortices that form behind the island induce updrafts to trigger cloud formation at the top of the convective boundary layer. A sensitivity experiment in which surface drag on the island is eliminated demonstrates that the formation mechanism of the atmospheric Kármán vortex shedding is different from that behind a bluff body in classical fluid mechanics.

Resource Sharing in Libraries on Cloud Landscape: Potentials and Paradoxes

<p>The initial hype of any development can eclipse its practical applications. The present paper attempts to separate the hype of cloud computing and explores the possibilities of resource sharing in libraries through Cloud Computing. The present study is based on the usage pattern of cloud computing in libraries and explores a model for resource sharing. It also proposes a cloud based resource sharing framework for moving from ground to the cloud. Although a lot of work has been done on cloud computing yet none of the works has been dedicated to the cause of libraries. With the development of electronic resources and shift in user’s preference of online services there is an urgent need of change in library practices.</p>

Tropical cyclone activity in nested regional and global grid-refined simulations

The capacity of two different grid refinement methods—two-way limited area nesting and variable-mesh refinement—to capture Northwest Pacific Tropical Cyclone (TC) activity is compared in a suite of single-year continuous simulations. Simulations are conducted with and without regional grid refinement from approximately 100–20 km grid spacing over the Northwest Pacific. The capacity to capture smooth transitions between the two resolutions varies by grid refinement method. Nesting shows adverse influence of the nest boundary, with the boundary evident in seasonal average cloud patterns and precipitation, and contortions of the seasonal mean mid-latitude jet. Variable-mesh, on the other hand, reduces many of these effects and produced smoother cloud patterns and mid-latitude jet structure. Both refinement methods lead to increased TC frequency in the region of refinement compared to simulations without grid refinement, although nesting adversely affects TC tracks through the contorted mid-latitude jet. The variable-mesh approach leads to enhanced TC activity over the Southern Indian and Southwest Pacific basins, compared to a uniform mesh simulation. Nesting, on the other hand, does not appear to influence basins outside the region of grid refinement. This study provides evidence that variable mesh may bring benefits to seasonal TC simulation over traditional nesting, and demonstrates capacity of variable mesh refinement for regional climate simulation.

Numerical investigation of fragmentation initiation threshold for sphere impacting on thin wall at hypervelocity

The sphere impacting on the thin wall is simulated with node-separation finite element method, and investigations of the projectile fragmentation initiation threshold are processed based on the numerical results. The bumper-thickness-to-projectile-diameter ratio ( t/ D) is found to be the main determinant of the velocity threshold. The simulation cases contain the t/ D ranging from 0.008 to 0.424 and impact velocity ranging from 2 km/s to 7 km/s. The numerical results are in good agreement with the tests in sphere fragmentation initiation threshold, inner spall of the sphere, debris cloud pattern. The simulations reproduce the fragmentation initiation threshold curve that is obtained by the tests. That shows the feasibility of node-separation finite element method for hypervelocity impact simulation. The shock wave analyses show that the propagation/reflection process of shock wave in the thin wall cases is very different from that in thick wall cases. That inherently results in the different variations of the threshold in the low and high intervals of t/ D. The extreme thin plate case shows that when t/ D is further reduced, a thick layer of debris cloud would form at the rear of the plate. Compared to the projectile residual, the debris cloud from the plate would induce wider destruction in the inner structure.

The Five Colours in Polychrome Silks with Cloud Pattern from Han Dynasty to Wei Period

The Five Colours in Polychrome Silks with Cloud Pattern from Han Dynasty to Wei Period

Bag-of-Words and Object-Based Classification for Cloud Extraction From Satellite Imagery

Automatic cloud extraction from satellite imagery is an important task for many applications in remote sensing. Humans can easily identify various clouds from satellite images based on the visual features of cloud. In this study, a method of automatic cloud detection is proposed based on object classification of image features. An image is first segmented into superpixels so that the descriptor of each superpixel can be computed to form a feature vector for classification. The support vector machine algorithm is then applied to discriminate cloud and noncloud regions. Thereafter, the GrabCut algorithm is used to extract more accurate cloud regions. The key of the method is to deal with the highly varying patterns of clouds. The bag-of-words (BOW) model is used to construct the compact feature vectors from densely extracted local features, such as dense scale-invariant feature transform (SIFT). The algorithm is tested using 101 RapidEye and 86 Landsat images with many cloud patterns. These images achieve 89.2% of precision, 87.8% of recall for RapidEye, 85.8% of precision, and 83.9% of recall for Landsat. The experiments show that the method is insensitive to the number of codewords in the codebook construction of the BOW.

An Evaluation of Advanced Dvorak Technique–Derived Tropical Cyclone Intensity Estimates during Extratropical Transition Using Synthetic Satellite Imagery

Abstract It is known that both Dvorak technique and advanced Dvorak technique–derived intensity estimates for tropical cyclones during extratropical transition are less reliable because the empirical relationships between cloud patterns and cyclone intensity underlying each technique are primarily tropical in nature and thus less robust during extratropical transition. However, as direct observations of cyclone intensity during extratropical transition are rare, the precise extent to which such remotely sensed intensity estimates are in error is uncertain. To address this uncertainty and provide insight into how advanced Dvorak technique–derived intensity estimates during extratropical transition may be improved, the advanced Dvorak technique is applied to synthetic satellite imagery derived from 25 numerical simulations of Atlantic basin tropical cyclones—five cases, five microphysical parameterizations—during extratropical transition. From this, an internally consistent evaluation between model-derived and advanced Dvorak technique–derived cyclone intensity estimates is conducted. Intensity estimate error and bias peak at the beginning of extratropical transition and decline thereafter for maximum sustained surface wind. On average, synthetic advanced Dvorak technique–derived estimates of maximum sustained surface wind asymptote toward or remain near their weakest-possible values after extratropical transition begins. Minimum sea level pressure estimates exhibit minimal bias, although this result is sensitive to microphysical parameterization. Such sensitivity to microphysical parameterization, particularly with respect to cloud radiative properties, suggests that only qualitative insight regarding advanced Dvorak technique–derived intensity estimate error during extratropical transition may be obtained utilizing synthetic satellite imagery. Implications toward developing improved intensity estimates during extratropical transition are discussed.

A cloud-based system for automatic glaucoma screening.

In recent years, there has been increasing interest in the use of automatic computer-based systems for the detection of eye diseases including glaucoma. However, these systems are usually standalone software with basic functions only, limiting their usage in a large scale. In this paper, we introduce an online cloud-based system for automatic glaucoma screening through the use of medical image-based pattern classification technologies. It is designed in a hybrid cloud pattern to offer both accessibility and enhanced security. Raw data including patient's medical condition and fundus image, and resultant medical reports are collected and distributed through the public cloud tier. In the private cloud tier, automatic analysis and assessment of colour retinal fundus images are performed. The ubiquitous anywhere access nature of the system through the cloud platform facilitates a more efficient and cost-effective means of glaucoma screening, allowing the disease to be detected earlier and enabling early intervention for more efficient intervention and disease management.

Automatic Dynamic Data Structures Recognition to Support the Migration of Applications to the Cloud

The work presented in this manuscript describes a methodology for the recognition of Dynamic Data structures, with a focus on Queues, Pipes and Lists. The recognition of such structures is used as a basis for the mapping of sequential code to Cloud Services, in order to support the semi-automatic restructuring of source software. The goal is to develop a complete methodology and a framework based on it to ease the efforts needed to port native applications to a Cloud Platform and simplify the relative complex processes. In order to achieve such an objective, the proposed technique exploits an intermediate representation of the code, consisting in parallel Skeletons and Cloud Patterns. Logical inference rules act on a knowledge base, built during the analysis of the source code, to guide the recognition and mapping processes. Both the inference rules and knowledge base are expressed in Prolog. A prototype tool for the automatic analysis of sequential source code and its mapping to a Cloud Pattern is also presented.

CHARM: A Cost-Efficient Multi-Cloud Data Hosting Scheme with High Availability

Nowadays, more and more enterprises and organizations are hosting their data into the cloud, in order to reduce the IT maintenance cost and enhance the data reliability. However, facing the numerous cloud vendors as well as their heterogenous pricing policies, customers may well be perplexed with which cloud(s) are suitable for storing their data and what hosting strategy is cheaper.The general status quo is that customers usually put their data into a single cloud (which is subject to the vendor lock-in risk) and then simply trust to luck. Based on comprehensive analysis of various state-of-the-art cloud vendors, this paper proposes a novel data hosting scheme (named CHARM) which integrates two key functions desired. The first is selecting several suitable clouds and an appropriate redundancy strategy to store data with minimized monetary cost and guaranteed availability. The second is triggering a transition process to re-distribute data according to the variations of data access pattern and pricing of clouds. We evaluate the performance of CHARM using both trace-driven simulations and prototype experiments. The results show that compared with the major existing schemes, CHARM not only saves around 20 percent of monetary cost but also exhibits sound adaptability to data and price adjustments.

Characterization of cloud cover with a smartphone camera

ABSTRACTA smartphone sky camera and associated image analysis algorithm has been developed and validated to determine total cloud cover and the percentage of thick and thin clouds using supervised image classification for a range of cloud types, cloud cover from 4% to 98%, and solar zenith angles between 6° and 49°. Additionally, this system provides the percentage of total, thick, and thin clouds in proximity to the solar disc. The measurement errors were comparable to those associated with values obtained by commercial sky camera systems. The benefits of increasing the availability of cloud fraction measurements include the potential to develop improved local ultraviolet indices and weather forecasts and to provide a better understanding of cloud patterns required for the generation of solar energy.