NYU-VAGC: a galaxy catalog based on new public surveys

Here we present the New York University Value-Added Galaxy Catalog (NYU-VAGC), a catalog of local galaxies (mostly below a redshift of about 0.3) based on a set of publicly-released surveys (including the 2dFGRS, 2MASS, PSCz, FIRST, and RC3) matched to the Sloan Digital Sky Survey (SDSS) Data Release 2. Excluding areas masked by bright stars, the photometric sample covers 3514 square degrees and the spectroscopic sample covers 2627 square degrees (with about 85% completeness). Earlier, proprietary versions of this catalog have formed the basis of many SDSS investigations of the power spectrum, correlation function, and luminosity function of galaxies. We calculate and compile derived quantities (for example, K-corrections and structural parameters for galaxies). The SDSS catalog presented here is photometrically recalibrated, reducing systematic calibration errors across the sky from about 2% to about 1%. We include an explicit description of the geometry of the catalog, including all imaging and targeting information as a function of sky position. Finally, we have performed eyeball quality checks on a large number of objects in the catalog in order to flag deblending and other errors. This catalog is complementary to the SDSS Archive Servers, in that NYU-VAGC's calibration, geometrical description, and conveniently small size are specifically designed for studying galaxy properties and large-scale structure statistics using the SDSS spectroscopic catalog.Comment: accepted by AJ; full resolution version available at http://sdss.physics.nyu.edu/vagc/va_paper.ps; data files available at http://sdss.physics.nyu.edu/vagc

Coordination approaches and systems - part I : a strategic perspective

This is the first part of a two-part paper presenting a fundamental review and summary of research of design coordination and cooperation technologies. The theme of this review is aimed at the research conducted within the decision management aspect of design coordination. The focus is therefore on the strategies involved in making decisions and how these strategies are used to satisfy design requirements. The paper reviews research within collaborative and coordinated design, project and workflow management, and, task and organization models. The research reviewed has attempted to identify fundamental coordination mechanisms from different domains, however it is concluded that domain independent mechanisms need to be augmented with domain specific mechanisms to facilitate coordination. Part II is a review of design coordination from an operational perspective

Rendering real-time dashboards using a GraphQL-based UI Architecture

With the increase in the complexity of the systems being built and demand in the quality of service by the customers, developing and providing highly efficient real-time systems is one of the biggest challenges today for software enterprises. BluemixTM ─ IBM’s cloud offering implemented on Cloud Foundry, an open source “Platform as a Service” (PaaS), is an example of such a system. Currently, there are approx. 26 infrastructural services running in the background from where the data is fetched and is rendered on different dashboards of the system. However, the system suffers from performance issues. This thesis explores the performance improvements of the real-time dashboards by introducing our proposed GraphQL-based UI architecture which allows caching and asynchronous loading. The test results of this architecture’s implementation on the Bluemix Usage Dashboard show that the Real data renders 245% faster and the Switching Account 153% faster than the existing system

Data flown hallinta React.js-sovelluksessa

The scale and complexity of web applications is growing as applications move more and more to the users' browser instead of the server. New types of web applications called single-page applications are gaining popularity because they provide a good user experience. In a single-page application the application code is loaded to the user's browser on initial start up. After this navigation and other operations are executed in the users browser. Only additional needed data is fetched from the server in the background. As applications get more complex, frameworks and libraries are needed to aid building them. Frameworks are a base that applications can be built on top of. They provide generic functionality that helps speed up the development process. When building applications a particular question arises, how to handle the data flow from the server to the user, and how to handle updates if the data changes. In this thesis the target was to examine how to handle the data flow in a user interface library called React.js. Since React.js is a UI library, it needs application architecture to handle the data flow. In this thesis an example application is created using application architecture called Flux. The same application is also created using an improved version of Flux called Redux. Since the exactly same example is implemented with both alternatives, they can be compared with each other. Based on the examined applications it can be clearly said that both, Flux and Redux, implement the same architecture at a general level. The example applications were similar, but it was visible that Redux is an improved version of the Flux architecture. This could be seen especially in the use of helper methods in parts that are verbose and error-prone in the Flux version. As a conclusion it was noted that instead of the original Flux architecture, Redux could have been compared with another improved implementation of Flux

Tablet-based math application for primary school pupils in Grade 1 and Grade 2

Applied project submitted to the Department of Computer Science, Ashesi University, in partial fulfillment of Bachelor of Science degree in Computer Science, April 2019Education is one of the basic needs of a child. The knowledge imparted through education is key to the recipient’s growth and skilfulness. In most cases, education is attained by attending a school (face to face) where several subjects are taught. Of all the subjects taught in schools, mathematics is a fundamental subject that cuts across all disciplines, hence a significant field for all school-going children. For some children, they find it easy to understand basic mathematical concepts and excel tremendously in the subject. However, quite a number struggle to learn both deep mathematical concepts and the most essentials skills such as addition, subtraction, multiplication, fractions, and decimals. As a result, this project seeks to develop a tablet-based math application for primary school pupils in grade 1 and grade 2, based on the Ghanaian education system. The app simplifies addition, subtraction and object grouping for pupils by making it fun through interactive game like activities.Ashesi Universit

Firefly: Embracing Future Web Technologies

At IPAC/Caltech, we have developed the Firefly web archive and visualization system. Used in production for the last eight years in many missions, Firefly gives the scientist significant capabilities to study data. Firefly provided the first completely web based FITS viewer as well as a growing set of tabular and plotting visualizers. Further, it will be used for the science user interface of the LSST telescope which goes online in 2021. Firefly must meet the needs of archive access and visualization for the 2021 LSST telescope and must serve astronomers beyond the year 2030. Recently, our team has faced the fact that the technology behind Firefly software was becoming obsolete. We were searching for ways to utilize the current breakthroughs in maintaining stability, testability, speed, and reliability of large web applications, which Firefly exemplifies. In the last year, we have ported the Firefly to cutting edge web technologies. Embarking on this massive overhaul is no small feat to say the least. Choosing the technologies that will maintain a forward trajectory in a future development project is always hard and often overwhelming. When a team must port 150,000 lines of code for a production-level product there is little room to make poor choices. This paper will give an overview of the most modern web technologies and lessons learned in our conversion from GWT based system to React/Redux based system