243 research outputs found
Characterization of TLB and page allocation behavior on modern processors
No full textVirtual memory support is prevalent in most modern processors and is facilitated through Translation Lookaside Buffers (TLBs) which play a major role in the overall system performance. TLB misses are costly since they require multiple high latency memory references to walk the page table and locate the desired Virtual Page Number (VPN) - Physical Page Number (PPN) mapping. This study improves TLB hit rates by taking advantage of any contiguity present in the pages allocated by the Operating System (OS). By contiguity we refer to cases where consecutive VPNs are mapped to consecutive PPNs. Traditionally, OSs use large or superpages to collapse hundreds of such contiguous entries, thereby using one TLB entry to represent them rather than hundreds of entries they would normally require. Unfortunately due to implementation complexities superpaging has not been universally successful in reducing TLB pressure. We show, however, that even without explicit superpaging, various OS virtual memory allocation activities lead to intermediate levels of contiguity that may be exploited to coalesce TLB entries and significantly improve hit rates. We verify the presence of contiguity by running benchmarks on a real system and checking the page allocations of the OS. The OS page allocation schemes depend on memory pressure and memory defragmentation daemons. Further, we find an average contiguity of 30 pages over all the benchmarks and configurations with superpaging turned on and about 10 with superpaging turned off. To verify the performance of a Coalesced TLB we have implemented a fully associative TLB with variable size and Least Recently Used (LRU) replacement policy. Our results show an average hit rate improvement of 25% by adding an 8-16 entry fully associative Coalesced TLB. The Coalesced TLB further needs no complex hardware to implement, hence providing to a low cost means to reduce miss rates.M.S.Includes bibliographical referencesby Viswanathan Vaidyanatha
Sustainable product and market development for subsistence marketplaces: Creating educational initiatives in radically different contexts
No full textDeveloping products and business processes to serve subsistence marketplaces (or the roughly 4 billion poor around the world referred to as the bottom of the pyramid) is a significant challenge for businesses. Despite the importance of subsistence marketplaces, most product development educational curricula have been focused on relatively resource-rich and literate consumers and markets. We teach an innovative year-long product development course which includes an international immersion experience and which covers a broad spectrum of learning from understanding poverty, to consumer behavior, to product development and engineering design specifically for subsistence consumers. This unique course represents a pioneering effort to focus attention and create knowledge about product development, marketing, management, and engineering practices for subsistence marketplaces. Our two-semester course sequence for graduate-level students in a variety of business and engineering disciplines and industrial design combines in-class pedagogy with experiential learning and results in useful and marketable product concepts and prototypes. Working on projects with multinational companies or startups, students identify an opportunity of general need, conduct field market research to better understand subsistence consumer needs and contexts through an international immersion experience, develop a product concept, convert the concept to a workable prototype, and develop a manufacturing plan, marketing strategy, and overall business plan for the product. Overlaying the content found in a typical new product development lab course we develop a contextual understanding of subsistence marketplaces, setting the stage for new product development. A central aspect of the learning experience is travel to subsistence markets for actual immersion in the context and to conduct market research. Our course is at the confluence of two of the most important issues facing humanity, subsistence and sustainability. Lessons learned here can also be extended to other radically different contexts, such as future scenarios involving severe energy shortages or climate change consequences. Such educational initiatives provide challenging learning experiences in preparing students for the unique demands of the 21st century. © 2011 Product Development and Management Association.APPLE LE, 1988, J PROD INNOVAT MANAG, V5, P70, DOI 10.1111-1540-5885.510070; ASHBY M, 2003, MATER TODAY, V6, P24, DOI 10.1016-S1369-7021(03)01223-9; Cardozo RN, 2002, J PROD INNOVAT MANAG, V19, P4, DOI 10.1016-S0737-6782(01)00116-3; CHICK A, 1997, J SUSTAINABLE PRODUC, V1, P53; Donaldson KM, 2006, RES ENG DES, V17, P135, DOI 10.1007-s00163-006-0017-3; Ehrenreich B., 2002, NICKEL DIMED; Eppinger S.D., 2002, DESIGN MANAGEMENT J, V13, P58; GESCHKA H, 1986, J PROD INNOVAT MANAG, V3, P48, DOI 10.1016-0737-6782(86)90043-3; GREEN M, 2006, P ASME DES ENG TECHN; HAMMOND A. L., 2007, INNOVATIONS, V2, P147, DOI [10.1162-itgg.2007.2.1-2.147, DOI 10.1162-ITGG.2007.2.1-2.147]; HANNUKAINEN P, 2006, P ASME DES ENG TECHN; Hargadon A, 2000, HARVARD BUS REV, V78, P157; HAUSER JR, 1988, HARVARD BUS REV, V66, P63; HERSTATT C, 1992, J PROD INNOVAT MANAG, V9, P213, DOI 10.1016-0737-6782(92)90031-7; HORAN J, 2004, ONE PAGE BUSINESS PL; Murcott S., 2007, J INT DEV, V19, P123, DOI 10.1002-jid.1353; Prahalad CK, 2002, HARVARD BUS REV, V80, P48; PRAHALAD CK, 2005, FORT BOTT PYR ER POV; PUGH P, 1991, TOTAL DESIGN INTEGRA; Rodriguez J, 2006, INTERACT COMPUT, V18, P956, DOI 10.1016-j.intcom.2006.05.007; Sahlman WA, 1997, HARVARD BUS REV, V75, P98; Schumacher Ernest F., 1973, SMALL IS BEAUTIFUL E; *SME, 2003, PLAST INJ MOLD; *SME, 2004, FUND MAN PROC SAMPL; Sridharan S, 2008, J CONSUM MARK, V25, P455, DOI 10.1108-07363760810915671; Stone R. B., 2000, Design Studies, V21, DOI 10.1016-S0142-694X(99)00003-4; TAGUCHI J, 1990, HARVARD BUS REV, V68, P65; Tybout JR, 2000, J ECON LIT, V38, P11, DOI 10.1257-jel.38.1.11; Ulrich K., 2007, PRODUCT DESIGN DEV; Viswanathan M, 2005, J MARKETING, V69, P15, DOI 10.1509-jmkg.69.1.15.55507; Viswanathan M., 2009, IVEY BUSINESS J MAR; Viswanathan M, 2009, J MACROMARKETING, V29, P406, DOI 10.1177-0276146709345620; Viswanathan M, 2008, EDUC ASIA PAC REG-IS, V12, P1, DOI 10.1007-978-1-4020-5769-4; Viswanathan M., 2007, PRODUCT MARKET DEV S, P1; Viswanathan M., 2007, PRODUCT MARKET DEV S, P212
Outside the fold conversion, modernity, and belief
No full text"Outside the Fold is a radical reexamination of religious conversion. Gauri Viswanathan skillfully argues that conversion is an interpretive act that belongs in the realm of cultural criticism. To that end, this work examines key moments in colonial and postcolonial history to show how conversion questions the limitations of secular ideologies, particularly the discourse of rights central to both the British empire and the British nation-state. Implicit in such questioning is an attempt to construct an alternative epistemological and ethical foundation of national community. Viswanathan grounds her study in an examination of two stimultaneous and, she asserts, linked events: the legal emancipation of religious minorities in England and the acculturation of colonial subjects to British rule. The author views these two apparently disparate events as part of a common pattern of national consolidation that produced the English state. She seeks to explain why resistance, in both cases, frequently took the form of religious conversion, especially to "minority" or alternative religions. Confronting the general characterization of conversion as assimilative and annihilating of identity, Viswanathan demonstrates that a willful change of religion can be seen instead as an act of opposition. Outside the Fold concludes that, as a form of cultural crossing, conversion comes to represent a vital release into difference.""Through the figure of the convert, Viswanathan addresses the vexing question of the role of belief and minority discourse in modern society. She establishes new points of contact between the convert as religious dissenter and as colonial subject. This convergence provides a transcultural perspective not otherwise visible in literary and historical texts. It allows for radically new readings of significant figures as diverse as John Henry Newman, Pandita Ramabai, Annie Besant, and B. R. Ambedkar, as well as close studies of court cases, census reports, and popular English fiction. These varying texts illuminate the means by which discourses of religious identity are produced, contained, or opposed by the languages of law, reason, and classificatory knowledge. Outside the Fold is a challenging, provocative contribution to the multidisciplinary field of cultural studies. Book jacket."--BOOK JACKE
An integrated spatial snap-shot monitoring method for identifying seasonal changes and spatial changes in surface water quality
No full textSummaryIntegrated catchment-scale management approaches in large catchments are often hindered due to the poor understanding of the spatially and seasonally variable pathways of pollutants. High-frequency monitoring of water quality at random locations in a catchment is resource intensive and challenging. A simplified catchment-scale monitoring approach is developed in this study, for the preliminary identification of water quality changes – Integrated spatial snap-shot monitoring (ISSM). This multi-parameter monitoring approach is applied using the isotopes of water (δ18O-H2O and δD) and nitrate (δ15N-NO3− and δ18O-NO3−) together with the fluxes of nitrate and other solutes, which are used as chemical markers. This method involves selection of few sampling stations, which are identified as the hotspots of water quality changes within the catchment. The study was conducted in the peri-alpine Thur catchment in Switzerland, with two snap-shot campaigns (representative of two widely varying hydrological conditions), in summer 2012 (low flow) and spring 2013 (high flow). Significant spatial (varying with elevation) and seasonal changes in the sources of water were observed between the two seasons. A spatial variation of the sources of nitrate and the solute loads was observed, in tandem with the land use changes in the Thur catchment. There is a seasonal shift in the sources of nitrate, it varies from a strong treated waste water signature during the low flow season to a mixture of other sources (like soil nitrogen derived from agriculture), in the high flow season. This demonstrates the influence of other sources that override the influence of waste water treatment plants (WWTPs) during high flow in the Thur River and its tributaries. This method is expected to be a cost-effective alternative, providing snap-shots, that can help in the preliminary identification of the pathways of solutes and their seasonal/spatial changes in catchments
A Study to Evaluate the Effectiveness of Honey Dates Amla Mix in Improving Hemoglobin Level among Adolescent Girls with Anemia in a Selected School at Coimbatore
No full textAnemia is a most common health problem in India. Adolescent girls are a sizable segment of the Indian population and constitute a vulnerable group.
The present study was done to evaluate the effectiveness of honey dates amla mix in improving hemoglobin level among adolescent girls with anemia in Govt. High School at Vazhukuparai. The aim of the study was to improve the hemoglobin level by honey dates amla mix intervention.
The objectives of the study include;
1. To assess the hemoglobin level among adolescent girls with anemia.
2. To evaluate the effectiveness of honey dates amla mix in improving hemoglobin level among adolescent girls with anemia.
3. To determine the association between the hemoglobin level with their selected demographic variables.
The research design adopted to this study was a pre- experimental design. The conceptual framework for this study was based on the basis of Ernestine Wiedenbach Prescriptive Theory (1968). The study was conducted in Govt. High School,
Vazhukkuparai and 30 samples were selected by using simple random sampling technique. The demographic variables were assessed by using self administered questionnaire and the hemoglobin level was assessed by using Sahli’s method before
and after intervention. The intervention of daily prepared mix of fresh medium sized amla 10gm, 5 seedless dates, 10ml honey was given to adolescent girls daily for 30 days between breakfast and lunch. The collected data were analyzed by using both descriptive and inferential statistical methods.
The study findings revealed that Honey Dates Amla Mix is an effective intervention to improve the hemoglobin level among adolescent girls with anemia
REANALYSIS OF THE EMISSION SPECTRUM OF IN FOREIGN GASES
No full textA. L. Guy, K.S. Viswanathan, A. Sur, and J. Tellinghuisen, Chem. Phys. Lett. 73, 582 (1980). H. Hemmati and G. J. Collins, Chem. Phys. Lett. 67, 5 (1979). P. Venkateswarlu, Phys. Rev. 81. 821 (1951). R. D. Verma, Proc. Ind. Acad. Sci. 48A, 197 (1958). K.S. Viswanathan, A. Sur, and J. Tellinghuisen, J. Mol. Spectrosc. (in press).Author Institution:The emission spectrum of in foreign gases is studied as a function of pressure, temperature, end isotopic species, using a tesla discharge as Evidence is found for at least 12 of the 18 ion-pair states arising from , of which (2g) appears to be the lowest. The pressure- and temperature-dependent spectra support the suggestion that both the 3400-A system and a broad band near 5000 A originate from this state. High-resolution spectra show discrete structure in electronic bands at 2380 A, 2770 A, and 2880 A, in addition to the well-known F-X (2700 A), D-A(3400 A), and E-B (4300 A) systems. The 2380 system originates from a state near and terminates on the X state near v = 50. The 2770 system, which was previously as terminating on the X or B state, is now found to involve the A() The 2880 system terminates on a weakly bound lower slate which probably dissociates to ground-stale atoms. Work is continuing on the other electronic bands of the emission spectrum, most of which appear to be diffuse
Etiology and Treatment of Hypogonadism in Adolescents
No full textAdequate functioning at all levels of the hypothalamic-pituitary-gonadal axis is necessary for normal gonadal development and subsequent sex steroid production. Deficiencies at any level of the axis can lead to a hypogonadal state. The causes of hypogonadism are heterogeneous and may involve any level of the reproductive system. This review discusses various causes of hypogonadism, describes the evaluation of hypogonadal states, and outlines treatment options for the induction of puberty in affected adolescents. Whereas some conditions are clearly delineated, the exact etiology and underlying pathogenesis of many disorders is unknown
Effect of river restoration and hydrological changes on surface water quality: river reach-scale to catchment-scale study
No full textThèse de doctorat : Université de Neuchâtel, 2015La restauration des rivières est considérée comme méthode permettant d'agir sur la protection contre les crues, la reconstruction d'habitats naturels et l'amélioration de la qualité des eaux de surface. En général, les projets de restauration visent à atteindre plus d'un des objectifs précités du fait de leur connexité. L'effet de la restauration d'une rivière sur la qualité de l'eau reste relativement peu étudié. La première partie de cette thèse est vouée à l'analyse de différents cas d'études de restauration de rivière réalisés dans plusieurs pays. Nous sélectionnons et analysons des cas d'études pour lesquels la qualité de l'eau était le principal objectif visé par la restauration, pour quatre pays sur trois continents. Ces cas d'études montrent que pour atteindre un objectif de bonne qualité de l'eau au sein des rivières restaurées, il est souvent nécessaire de combiner aux mesures de restauration une amélioration (ou une installation) des infrastructures (tels que les stations d'épuration et bassins d'orage). Dans l'ensemble des études de restauration, le suivi post-restauration n'est pas souvent mené du fait d'un manque de fonds pour mener un suivi pre-restauration d'une part et d'un manque de protocole et d'indicateurs bien définis pour le contrôle de la qualité de l'eau d'autre part. L'un des buts principaux de cette thèse est de définir un jeu de paramètres afin d'offrir des indicateurs clés de la qualité de l'eau pour le suivi pre et post restauration. Dans la seconde partie de cette thèse, un suivi à haute fréquence d'un grand nombre de paramètres a été réalisé afin d'identifier les paramètres clés et les processus bio-géochimiques qui affectent leurs cycles diurne au cours de trois saisons. Le fonctionnement de l'écosystème en rivière et la théorie selon laquelle la capacité d'assimilation des nutriments des rivières est étudié et testée pour plusieurs conditions hydrologiques. Nous montrons que les cycles diurnes du pH et de l'oxygène dissout (DO) sont dépendants des processus biologiques, principalement la photosynthèse et la respiration, en rivière. Pendant la période de basses eaux, en automne, nous avons observé une réduction du carbone organique dissous (DOC), pendant la nuit, et des nitrates, juste avant le lever du jour, à l'aval des biefs restaurés. Ceci est attribué à des processus biologiques supposés être accentués par une augmentation de la diversité des habitats post-restauration. Par ailleurs, suite à un évènement orageux d'été, nous avons pu observer une augmentation des nitrates et une accumulation du chlore à l'exutoire du bassin versant suivi par une dilution retardée comparée aux effets de dilution immédiats observés quant à eux le long du reste de la rivière. Cet évènement orageux a aussi causé une diminution du DOC par dilution le long de toute la rivière. L'observation de la diminution de la variabilité diurne du DO dans les parties chenalisées de la rivière pendant l'évènement orageux est un indicateur d'une augmentation du taux de renouvellement de la turbidité qui affecte le modèle de production-respiration - mais qui n'affecte pas la variabilité diurne de la partie restaurée. Un plus long bief restauré et un suivi pre-restauration sont recommandés pour les projets futurs. Dans la dernière partie de cette thèse, nous employons une démarche à l'échelle du bassin versant afin d'identifier les chemins de transferts des solutés. La méthode simplifiée intitulée "Integrated Spatial Snap-shot Method" (ISSM) ou Méthode d'Aperçu Spatialement Intégrée, implique l'identification d'un nombre réduit ( Im ersten Teil dieser Doktorarbeit werden verschiedene Revitalisierungsprojekte, welche prioritär eine Verbesserung der Wasserqualität anstrebten, untersucht. Dabei werden Projekte aus vier Ländern dreier Kontinente berücksichtigt. Die Auswertung verdeutlicht, dass Revitalisierungsmassnahmen alleine nicht ausreichen, um die Wasserqualität zu verbessern. Zusätzliche Aufwertungen der Infrastruktur, wie beispielsweise durch Kläranlagen oder Kanalisationen, sind hierbei notwendig, um eine gute Wasserqualität zu erreichen. Häufig ist es aufgrund fehlender Kontrollen, welche vor Beginn bzw. nach Beendigung der Revitalisierung, durchgeführt werden, unmöglich festzustellen, ob das Projekt eine Verbesserung der Wasserqualität bewirkt hat. Die mangelnden Kontrollen sind, zum einen, auf ein streng limitiertes Budget, zum anderen, auf unzureichende Vorgaben bezüglich notwendiger Vor- und Nachuntersuchungen zurückzuführen. Ein wichtiges Anliegen dieser Doktorarbeit ist daher die Identifikation von chemischen Parametern, welche als Indikator der Wasserqualität dienen können. Durch Vorgabe dieser Indikatoren sollen Vor- und Nachuntersuchungen stark vereinfacht und kosteneffizienter gestaltet werden. Anhand von Vergleichsstudien an einem Feldstandort in der Nordost-Schweiz werden im zweiten Teil dieser Doktorarbeit chemische Indikatoren identifiziert. Zusätzlich werden die Auswirkungen bio-geochemische Prozesse auf die täglichen Schwankungen der zuvor genannten chemischen Indikatoren untersucht. Daten wurden hierbei während dreier verschiedener Jahreszeiten über einen Zeitraum von ca. zwei Jahren erhoben und ausgewertet. Hierbei liegt das Augenmerk der Datenauswertung auf der Funktionsfähigkeit der Flussökosysteme. Des Weiteren wird anhand verschiedener hydrogeologischer Szenarien untersucht, inwiefern Flussrevitalisierungen die Verfügbarkeit von Nährstoffen verbessern. Die Daten verdeutlichen, dass tägliche Schwankungen im pH-Wert und der Konzentration gelösten Sauerstoffs auf biologische Prozesse, d.h. Photosynthese und Respiration, zurückzuführen sind. Bei Daten der Probennahmen im Herbst zeigen sich im unterstromigen Bereich des revitalisierten Abschnittes am Feldstandort nachts und im Morgengrauen jeweils niedrigere Konzentrationen gelösten organischen Kohlenstoffs und Nitrat. Es wird vermutet, dass dies durch eine höhere biologische Aktivität, welche nach Flussrevitalisierungen erwartet wird, bedingt ist. Ein anderes Bild zeigt sich während eines Starkregenereignisses im Sommer. Hier werden am Abstrom des Einzugsgebietes erhöhte Konzentrationen an Nitrat und Chlorid gemessen. Dabei wird hier eine verzögerte Verdünnung der Konzentrationen beobachtet, die sich stark von der sofortigen Konzentrationsverringerung in den anderen Messstationen unterscheidet. Das Starkregenereignis führt zu einer Reduktion der Konzentrationen an gelöstem organischen Kohlenstoff im gesamten Untersuchungsbereich des Flusses. Weiter zeigt sich eine Veränderung in den täglichen Schwankungen des gelösten Sauerstoffs, jedoch ausschliesslich im kanalisierten, nicht revitalisierten, Bereich des Flusses. Diese Verringerung der täglichen Schwankungen im gelösten Sauerstoff ist auf die hohe Trübung zurückzuführen, welche die biologische Aktivität, z.B. die Respiration, beeinträchtigt. Für zukünftige Forschungsprojekte wäre es empfehlenswert bereits vor der Revitalisierung detaillierte Untersuchungen der Wasserchemie durchzuführen. Zusätzlich wäre es hilfreich für die Untersuchungen nach der Revitalisierung über einen möglichst langen revitalisierten Abschnitt zu verfügen. Im letzten Teil dieser Doktorarbeit wird ein Vorgehen vorgeschlagen, mit welchem innerhalb eines Einzugsgebietes die Fliesspfade verschiedener gelöster Stoffe nachvollzogen werden können. Hierbei werden mit der neu entwickelten ISSM-Methode („Integrated Spatial Snap-shot“) im Einzugsgebiet eine geringe Anzahl repräsentativer Knotenpunkte für die Untersuchung der gelösten Stoffe identifiziert. Anhand dieser werden dann die Stoffflüsse bei unterschiedlichen Abflussszenarien und zu unterschiedlichen Jahreszeiten untersucht. Diese Methode wurde an verschiedenen Feldstandorten angewandt. So wurden Hotspots chemischer Indikatorspezies und deren jahreszeitlichen Schwankungen anhand der Konzentrationen gelöster Stoffe und deren Durchflussmenge sowie der Wasserstoff-/Sauerstoff- und Stickstoff-Isotopenverteilung untersucht. Es zeigt sich, dass sich diese Methode auf Einzugsgebiete mit unterschiedlichsten Topographien übertragen lässt. Auf diese Weise lassen sich in ersten Voruntersuchungen potentielle Standorte für Flussrevitalisierungen auch innerhalb grosser Einzugsgebiete identifizieren
Adaptive transmit power control based on signal strength and frame loss measurements for WLANs:
No full textIn the past few years, we witnessed a rapid penetration of Wireless Local Area Networks (WLANs) into the home and enterprise. Emerging technology such as the IEEE 802.11n radio, which is getting increasingly affordable, makes delivering multimedia content over
wireless networks possible and this would drive the technology further into our daily life. As the number of available wireless channels in the unlicensed spectrum is limited (3 non-overlapping channels in 2.4GHz unlicensed band and up to 24 non-overlapping channels in 5GHz unlicensed band), they have to be shared by multiple WLANs consisting of Access Points (APs) and STAtions (STAs). In a Multi-Dwelling Unit (MDU) WLAN deployment, e.g. in an apartment building or hotel, transmissions in overlapping cells tend to interfere with each other. This will adversely impact the aggregate wireless network throughput and thus the quality of experience for applications such as multimedia streaming. Hence there is a need for automatic and adaptive resource management strategy to ensure a good overall network performance.
In this thesis we propose an adaptive per-link Transmit Power Control (TPC) solution for WLANs. TPC can reduce interference, increase channel reuse, and eventually increase the overall capacity in dense 802.11 wireless networks. However intelligent algorithms are
required to adapt transmit power in a practical and distributed way to achieve improvement in performance. It becomes more challenging given different types of interference (cooperative and non-cooperative) in the unlicensed band as well as the hidden node problem. From a detailed study of the previous efforts at power control, we observe that in order to make better decisions on transmit power; an AP needs to actively monitor several factors. Hence we develop a TPC algorithm based on both link margin estimation as well as frame loss rate measurement. Compared to previous solutions that adapt the transmit power based on measurement of a single parameter (either received signal strength or frame loss rate), the proposed power control mechanism can diagnose and take remedial action for hidden nodes and channel access asymmetry problems manifesting as frame losses. It is adaptive to mobility, complementary to any rate control algorithm and can also be incrementally deployed amidst non-cooperative nodes. We have implemented the algorithm as an application running on Atheros chipset-based 802.11n APs, taking practical system-level limitations into account. The proposed solution achieves significant transmit power reduction at the APs (to as low as 60% of the maximum power) for STAs as far as 70ft and over ∼60% increase in total network throughput through interference mitigation.M.S.Includes bibliographical references (p. 47-48)by Hariharasudhan Viswanatha
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