165 research outputs found
Preliminary Assessment of Performance and Cost of a Cubesat Component of the Earth Science Decadal Survey
In 2007, The National Research Council released a report known as the Earth Science Decadal Survey. This report lays out an architecture for a holistic Earth Observation Program consisting of 17 missions to be flown in a decade for a total cost of about $7B. Six years after, mission cost estimates have grown by 70% on average, and at the current levels of funding for NASA Earth Science, it would take about 40 years to fly these missions. Furthermore, missions that played central roles in satisfying the needs of the Earth science community have not materialized, due to launch failures, mission cancellations, severe delays or descoping processes. The Earth Science community is in desperate need of novel architectures for Earth observation missions that can satisfy at least part of the scientific requirements at a fraction of the cost of the Decadal Survey missions. Cubesats have the potential to become an important component of such novel architectures by providing low-cost opportunities to fly advanced miniature instruments such as GNSS receivers in radio occultation and reflectometry modes, visible and near-infrared imagers, short-wave infrared spectrometers, millimeter-wave radiometers, microbolometers, and so forth. While Cubesats have hitherto mostly been used for technological demonstration and educational purposes, there has been some emphasis lately in developing Cubesats capable of satisfying demanding scientific requirements. In a recent paper, a survey and assessment of the capabilities of Cubesats as a platform for Earth observation instruments of high scientific value, was presented. This paper takes that work a step further by analyzing, in terms of both performance and cost, several constellations of Cubesats carrying such instruments. The performance of an architecture (i.e., a certain mix of constellations of Cubesats) is computed by assessing its potential to satisfy the Decadal Survey scientific requirements. This is done leveraging prior work on the development of a rule-based expert system for assessing the relative merit of Earth observing system architectures. Different constellation designs carrying different mixes of payloads are analyzed using performance and cost models. Non-dominated architectures in the Pareto sense are identified, and one preferred architecture is analyzed in more detail. A preliminary mission analysis is conducted for this preferred architecture, and its cost-effectiveness is compared to that of the original Decadal Survey architecture. The paper shows how, while Cubesats still suffer from serious limitations in terms of their performance and capabilities for Earth science, they are a very cost-effective way of satisfying a relatively large portion of the Decadal Survey requirements
Sistem Informasi Maintenance Building dan Human Resources Development Studi Kasus Harian Umum Palembang POS
Palembang POS merupakan perusahaan yang bergerak dibidang percetakan media masa dalam hal ini Koran. Perusahaan ini saat ini memiliki beberapa departemen dalam kegiatan operasioanl bisnis.salah satunya departemen HRD dan Building maintenance. Ada beberapa permasalahan yang sering terjadi pada departemen tersebut, antara lain masih belum terintegrasinya data pelamar detail pelamar pada proses penerimaan membuat sulitnya manajer dalam memproses penilaian pelamar. Pada bagian building maintentance, seringkali manajer tidak dapat melihat data building maintenance secara detail dikarenakan data berlum tersortir secara maksimal. Adanya masalah tersebut membuat penulis ingin membangun sebuah sistem informasi yang memproses setiap kegiatan reqruitmen karyawan dan proses pemeliharaan gedung ( building maintenance) pada perusahaan Palembang POS. Metodologi yang digunakan dalam pengembangan sistem ini adalah metodologi RUP , dengan tools identifikasi masalah berupa kerangka PIECES, sedangkan untuk analisis kebutuhan user digambarkan dengan use case diagram. Sistem ini dibangun menggunakan bahasa pemograman visual basic dengan SQL Server 2008 sebagai DBMS. Dengan adanya sebuah sistem informasi rekrutmen dan pemeliharaan gedung ini diharapkan dapat meningkatkan kualitas proses reqritmen dan pencatatan pemeliharaan gedung serta mempermudah mengolah semua data yang telah terintegrasi satu sama lain, serta memberikan laporan yang akurat bagi manager palembang POS
Rule-Based System Architecting of Earth Observing Systems: Earth Science Decadal Survey
This paper presents a methodology to explore the architectural trade space of Earth observing satellite systems, and applies it to the Earth Science Decadal Survey. The architecting problem is formulated as a combinatorial optimization problem with three sets of architectural decisions: instrument selection, assignment of instruments to satellites, and mission scheduling. A computational tool was created to automatically synthesize architectures based on valid combinations of options for these three decisions and evaluate them according to several figures of merit, including satisfaction of program requirements, data continuity, affordability, and proxies for fairness, technical, and programmatic risk. A population-based heuristic search algorithm is used to search the trade space. The novelty of the tool is that it uses a rule-based expert system to model the knowledge-intensive components of the problem, such as scientific requirements, and to capture the nonlinear positive and negative interactions between instruments (synergies and interferences), which drive both requirement satisfaction and cost. The tool is first demonstrated on the past NASA Earth Observing System program and then applied to the Decadal Survey. Results suggest that the Decadal Survey architecture is dominated by other more distributed architectures in which DESDYNI and CLARREO are consistently broken down into individual instruments."La Caixa" FoundationCharles Stark Draper LaboratoryGoddard Space Flight Cente
A rule-based method for scalable and traceable evaluation of system architectures
Despite the development of a variety of decision-aid tools for assessing the value of a conceptual design, humans continue to play a dominant role in this process. Researchers have identified two major challenges to automation, namely the subjectivity of value and the existence of multiple and conflicting customer needs. A third challenge is however arising as the amount of data (e.g., expert judgment, requirements, and engineering models) required to assess value increases. This brings two challenges. First, it becomes harder to modify existing knowledge or add new knowledge into the knowledge base. Second, it becomes harder to trace the results provided by the tool back to the design variables and model parameters. Current tools lack the scalability and traceability required to tackle these knowledge-intensive design evaluation problems. This work proposes a traceable and scalable rule-based architecture evaluation tool called VASSAR that is especially tailored to tackle knowledge-intensive problems that can be formulated as configuration design problems, which is demonstrated using the conceptual design task for a laptop. The methodology has three main steps. First, facts containing the capabilities and performance of different architectures are computed using rules containing physical and logical models. Second, capabilities are compared with requirements to assess satisfaction of each requirement. Third, requirement satisfaction is aggregated to yield a manageable number of metrics. An explanation facility keeps track of the value chain all along this process. This paper describes the methodology in detail and discusses in particular different implementations of preference functions as logical rules. A full-scale example around the design of Earth observing satellites is presented
Rule-based system architecting of Earth observation satellite systems
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 399-412).System architecting is concerned with exploring the tradespace of early, high-level, system design decisions with a holistic, value-centric view. In the last few years, several tools and methods have been developed to support the system architecting process, focusing on the representation of an architecture as a set of interrelated decisions. These tools are best suited for applications that focus on breadth - i.e., enumerating a large and representative part of the architectural tradespace -as opposed to depth - modeling fidelity. However, some problems in system architecting require good modeling depth in order to provide useful results. In some cases, a very large body of expert knowledge is required. Current tools are not designed to handle such large bodies of knowledge because they lack scalability and traceability. As the size of the knowledge base increases, it becomes harder: a) to modify existing knowledge or add new knowledge; b) to trace the results of the tool to the model assumptions or knowledge base. This thesis proposes a holistic framework for architecture tradespace exploration of large complex systems that require a large body of expert knowledge. It physically separates the different bodies of knowledge required to solve a system architecting problem (i.e., knowledge about the domain, knowledge about the class of optimization or search problem, knowledge about the particular instance of problem) by using a rule-based expert system. It provides a generic population-based heuristic algorithm for search, which can be augmented with rules that encode knowledge about the domain, or about the optimization problem or class of problems. It identifies five major classes of system architecting problems from the perspective of optimization and search, and provides rules to enumerate architectures and search through the architectural tradespace of each class. A methodology is also defined to assess the value of an architecture using a rule-based approach. This methodology is based on a decomposition of stakeholder needs into requirements and a systematic comparison between system requirements and system capabilities using the rules engine. The framework is applied to the domain of Earth observing satellite systems (EOSS). Three EOSS are studied in depth: the NASA Earth Observing System, the NRC Earth Science Decadal Survey, and the Iridium GEOscan program. The ability of the framework to produce useful results is shown, and specific insights and recommendations are drawn.by Daniel Selva Valero.Ph.D
Health in ultra endurance events: SUMMIT Lab® Project
High-intensity physical activity for an extended period of time could result in unhealthy disruptions to physiological systems. The main goal of the SUMMIT Lab® is to offer to ultra-endurance athletes an assessment of the impact of training with biochemical comparison of pre- and after-race measurements through biochemical (markers of muscle damage, immunity status and cardiovascular system) and physiological responses [localized muscle bioimpedance (LBIA)], cardiac function and differential gene expression. Samples were obtained from 300 participants who completed ultra-distance runs in Europe from 2012 to 2016. We found: (1) CK levels provide a gross indication of muscle-fiber damage but are not specific, they can’t identify the extent of the injury or the type of fibers affected; (2) LBIA serves to track the effects of training or a race on muscle damage, and enables longitudinal assessment of muscle injury through recovery and return to training. (3) Some individuals showed worse right ventricle adaptation during exercise independent from the training volume done or the elite profile. (4) Elite performance is mainly related with training. We have evidence that we can measure quantitatively the effect of training through a specific gene expression profile. Possible additional applications include runners, soccer, army physical condition, among others.Postprint (published version
Macronutrient and mineral intake effect on racing time and cardiovascular health in non-elite marathon runners.
Objective: The aim of this study was to analyze, in recreational marathon runners, the intake of specific macronutrients and minerals that could influence cardiovascular health.
Methods: 37 males were grouped in two groups according to their 50% percentile race time (3.39 h), dividing into fast (G1: 3.18 ± 0.18 h) and slow runners (G2: 3.84 ± 0.42 h). Anthropometric parameters, macronutrients and mineral records were collected before the race. Minerals (Na+, K+ and Mg2+), lipid profile (triglycerides, LDL, HDL and cholesterol), muscle damage (creatine kinase), inflammation (C-reactive protein), and cardiovascular health (high-sensitive troponin-T, ST2 and N-terminal pro-B-type natriuretic peptide) were analyzed in blood 24 h before, immediately after, and 48 h post-race.
Results: Weight (G1: 74.70 ± 7.76 kg, G2: 79.58 ± 6.72 kg; p < 0.05) and body mass index (G1: 23.01 ± 1.81 kg/m2, G2: 25.30 ± 2.02 kg/m2; p < 0.01) were significantly different between the groups. Moreover, G1 consumed significantly (p < 0.01) more mono- and poly-unsaturated fatty acids than G2, and presented significantly higher iron, potassium, and magnesium intake. Regarding blood lipid profile, G2 presented significantly higher triglyceride values and lower levels of high-density lipoprotein (p < 0.01). The Hs-TnT marker of cardiac myocyte stress/injury was significantly higher (p < 0.05) in G2 reaching values above 250 ng/L, and 81% of the runners (30 from 37) presented higher post-race values.
Conclusions: Marathon runners consuming adequate amounts of unsaturated fat, iron, potassium and magnesium, performed better and presented better cardiovascular health.Peer ReviewedPostprint (author's final draft
Dispositivos de formación universitaria en economía social y solidaria : La Tecnicatura Universitaria en Economía Social y Solidaria de la Universidad Nacional de Quilmes
El presente trabajo se propone compartir la experiencia pedagógica y territorial en la primera Tecnicatura Universitaria en Economía Social y Solidaria (TUESS) de la Universidad Nacional de Quilmes. Esta propuesta parte de un diagnóstico de la demanda social de formación integral, surgida del trabajo con las propias experiencias territoriales y de la vinculación con políticas públicas en Economía Social y Solidaria (ESS). Desde allí su formalización como oferta de educación superior universitaria.
Para la experiencia formativa se han privilegiado dispositivos de la educación popular proponiendo para el trabajo áulico la Pareja Pedagógica (docente tutor y docente curricular) y la Comunidad de Aprendizaje en el acompañamiento de estudiantes adultos, trabajadores integrantes de organizaciones y movimientos sociales, culturales y políticos y agentes del sector público y privado con experiencias en cooperativas, mutuales, asociaciones, fundaciones. Basados en la concepción de Diálogo de Saberes estos dispositivos propician la responsabilidad colectiva de los aprendizajes.
La TUESS es un desafío en la producción de conocimientos en su doble forma de teoría y práctica, que aporta a la construcción del campo de la economía social y solidaria, sus valores en la búsqueda de transformación de las relaciones económicas, sociales, políticas y culturales instituidas.Eje 2. Economía social y Universidad, una relación estratégica para la expansión y fortalecimiento desde la educaciónFacultad de Ciencias Económica
Dispositivos de formación universitaria en economía social y solidaria : La Tecnicatura Universitaria en Economía Social y Solidaria de la Universidad Nacional de Quilmes
El presente trabajo se propone compartir la experiencia pedagógica y territorial en la primera Tecnicatura Universitaria en Economía Social y Solidaria (TUESS) de la Universidad Nacional de Quilmes. Esta propuesta parte de un diagnóstico de la demanda social de formación integral, surgida del trabajo con las propias experiencias territoriales y de la vinculación con políticas públicas en Economía Social y Solidaria (ESS). Desde allí su formalización como oferta de educación superior universitaria.
Para la experiencia formativa se han privilegiado dispositivos de la educación popular proponiendo para el trabajo áulico la Pareja Pedagógica (docente tutor y docente curricular) y la Comunidad de Aprendizaje en el acompañamiento de estudiantes adultos, trabajadores integrantes de organizaciones y movimientos sociales, culturales y políticos y agentes del sector público y privado con experiencias en cooperativas, mutuales, asociaciones, fundaciones. Basados en la concepción de Diálogo de Saberes estos dispositivos propician la responsabilidad colectiva de los aprendizajes.
La TUESS es un desafío en la producción de conocimientos en su doble forma de teoría y práctica, que aporta a la construcción del campo de la economía social y solidaria, sus valores en la búsqueda de transformación de las relaciones económicas, sociales, políticas y culturales instituidas.Eje 2. Economía social y Universidad, una relación estratégica para la expansión y fortalecimiento desde la educaciónFacultad de Ciencias Económica
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