No description available.

No description available.

Transmission Control Protocol (TCP) is the dominant transport protocol today and likely to be adopted in future high‐speed and optical networks. A number of literature works have been done to modify or tune the Additive Increase Multiplicative Decrease (AIMD) principle in TCP to enhance the network performance. In this work, to efficiently take advantage of the available high bandwidth from the high‐speed and optical infrastructures, we propose a Stratified TCP (STCP) employing parallel virtual transmission layers in high‐speed networks. In this technique, the AIMD principle of TCP is modified to make more aggressive and efficient probing of the available link bandwidth, which in turn increases the performance. Simulation results show that STCP offers a considerable improvement in performance when compared with other TCP variants such as the conventional TCP protocol and Layered TCP (LTCP).

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 1998. / Includes bibliographical references.

Electrochromic smart windows offer a viable route to reducing the consumption of buildings energy, which represents about 30% of the worldwide energy consumption. Smart windows are far more compelling than current static windows in that they can dynamically modulate the solar spectrum depending on climate and lighting conditions or simply to meet personal preferences. The latest generation of smart windows relies on nominally transparent metal oxide nanocrystal materials whose chromism can be electrochemically controlled using the plasmonic effect. Plasmonic electrochromic materials selectively control the near infrared (NIR) region of the solar spectrum, responsible for solar heat, without affecting the visible transparency. This is in contrast to conventional electrochromic materials which block both the visible and NIR and thus enables electrochromic devices to reduce the energy consumption of a building or a greenhouse in warm climate regions due to enhancements of both visible lighting and heat blocking. Despite this edge, this technology can benefit from important developments, including low-cost solution-based manufacturing on flexible substrates while maintaining durability and coloration efficiency, demonstration of independent control in the NIR and visible spectra, and demonstration of self-powering capabilities. This thesis is focused on developing low-temperature and all-solution processed plasmonic electrochromic devices and dual-band electrochromic devices. We demonstrate new device fabrication approaches in terms of materials and processes which enhance electrochromic performance all the while maintaining low processing temperatures. Scalable fabrication methods are used to highlight compatibility with high throughput, continuous roll-to-roll fabrication on flexible substrates. In addition, a dualband plasmonic electrochromic device was developed by combining the plasmonic layer with a conventional electrochromic ion storage layer. This enables independent control of the transmittance of NIR and visible spectra and is done without time- and energyintensive synthesis and processing methods. We have fabricated self-powered smart windows by integrating the plasmonic and dual-band devices with organic photovoltaic mini-modules and introduced static color bias with the help of photonic crystals to explore a few possibilities of multi-platform building integration.

An architectural component can change urban environment. A great window to the city, typologically bounded in the form an ice rink is proposed in the post-industrial city of Baltimore. This proposal should be seen as part of the city that is undergoing a transition from an industrial to a commercial city. The ice rink is proposed on one of the vacant industrial sites along the water front, a site of historical importance. Its location in relation to the city offers a strong visual and the necessary physical connection to the city and the surrounding existing recreational spaces. The panoramic view of the city, a compelling element of the site became the driving force for type, organization and orientation of the building. The view of the city is constructed as an architectural element and the movement in the building as a visual event. The structure of the building is also developed to facilitate this visual progression. A wall, which complements the visual event, is introduced to act as backdrop for the building against the existing city sky line. The proposed urban corridor extends the existing fabric of the city. This corridor continues inside the building to culminate in the offering of the city as an architecturally framed panorama, a window to the city. / Master of Architecture

The building sector is one of the sectors that consume most energy in Sweden. Sweden aims thereby to reduce energy use in buildings by 20% by 2020 and 50% by 2050. To achieve these goals, more energyefficient buildings must be produced, and more energy-efficient measures must be implemented on existing buildings. Electrochromic windows are claimed to reduce the need for heating and cooling, as well as the need for artificial lighting. However, there is limited research on smart windows in the Nordic climate.   This thesis examines electrochromic windows in Sweden, using the IDA ICE 4.7.1 simulation program. The study includes a comparative analysis of an office building model with conventional windows and motorized awnings, versus electrochromic windows with different control strategies, to investigate the building’s impact. In total, eight different scenarios are simulated in Stockholm, Umeå and Malmö. The electrochromic window scenarios consist of control algorithms where the windows are always on or off, as well as algorithms that respond to sunlight, daylight, operative temperature or scheduling. The conventional windows and awnings scenario represents the reference building. The Swedish building certification system "Miljöbyggnad" is used as a guideline for evaluating energy use, heating power demand, solar heat load, thermal climate, and daylight.   The results show that electrochromic windows have little impact on the building. None of the scenarios succeed in obtaining higher certification than BRONZE, which corresponds to the authority's requirements for newly built buildings. However, electrochromic windows have a significant effect on the solar heat load and the lux level in the building, but unfortunately not enough to get a better building grade. There is no remarkable difference between the indicators and scenarios. Furthermore, the results show that scenarios that are shaded often (Always on, Daylight Control, Solar Control strategy) achieve GOLD ratings in solar heat load, but have the least impact on energy consumption and vice versa. Always off, Operative Temperature Control, and Schedule, Façade and Window strategy upgrades by one level in energy use. This confirm previous studies that claim that electrochromic windows have the greatest potential in energy saving in hot climate. This explains why there is hardly any difference between scenarios and cities.   The thesis lacks specific costs for electrochromic windows. Thus, the cost estimate is based on generalizations and assumptions, in which the cheapest and most expensive options are investigated. If the building has well-functioning windows and awnings, it is not cost effective to switch to electrochromic windows, since the payback time is far too long. But if the building was between conventional windows and electrochromic windows during the planning phase, it might be interesting to conduct a detailed cost analysis. According to this study, the Operative Temperature Control strategy saves approximately 6 333kr during the simulation period. The cost differences between conventional windows with motorized awnings, and the cheapest version of electrochromic windows is around 60 000kr. This would provide a refund within 10 years, given that energy prices, energy consumption and currency value are the same. After that, the window would cut the energy costs in the form of saved energy.   However, the study concludes that electrochromic windows are not necessary in this project from a Miljöbyggnad perspective, since the building grade remains the same and the economic gain is uncertain. / Byggnadssektorn är en av de sektorer som använder mest energi i Sverige. Därmed har Sverige som mål att minska energianvändningen i byggnader med 20% år 2020, och 50% år 2050. För att uppnå dessa mål måste fler energieffektiva byggnader produceras, samt fler energieffektiva åtgärder måste genomföras på befintliga byggnader. Elektrokroma fönster hävdas minska behovet av uppvärmning och kylning, samt behovet av artificiell belysning. Det finns dock begränsad forskning om smarta fönster i det nordiska klimatet.   Detta examensarbete undersöker elektrokroma fönster i Sverige, med hjälp av simuleringsprogrammet IDA ICE 4.7.1. Arbetet omfattar en jämförande analys av en kontorsbyggnadsmodell med vanliga fönster och motoriserade markiser, kontra elektrokroma fönster med olika kontrollstrategier, för att undersöka byggnadens påverkan. Sammanlagt simuleras åtta olika scenarier i Stockholm, Umeå och Malmö. De scenarier med elektrokroma fönster består följaktligen av kontroll algoritmer där fönsterna är alltid på eller avstängda, samt algoritmer som reagerar på solljus, dagsljus, operativa temperatur eller schemaläggning. Scenariot med vanliga fönster och markiser representerar referensbyggnaden. Det svenska byggnadscertifieringssystem ”Miljöbyggnad” används som riktlinje för evaluering av energianvändning, värmeeffektbehov, solvärmelast, termiskt klimat, och dagsljus. Resultaten visar att elektrokroma fönster har liten påverkan på byggnaden. Ingen av scenarierna lyckas få högre certifiering än BRONS, vilket motsvarar myndighetens krav på nybyggda byggnader. Dock så har elektrokroma fönster signifikant inverkan på solvärmelasten och lux nivån i byggnaden, men tyvärr inte tillräckligt för att få ett bättre byggnads betyg. Det är ingen anmärkningsvärd skillnad sinsemellan indikatorerna och scenarierna. Vidare visar resultaten att scenarier som är skuggade ofta (Alltid på-, Dagljuskontroll-, Solljuskontrollstrategin) uppnår GULD betyg inom solvärmelast men har minst inverkan på energiförbrukningen och vice versa, Alltid av-, operativa temperaturkontroll, samt schemaläggning, fasad och fönster strategin uppgraderas ett steg inom energianvändning. Detta styrker tidigare studier som påstår att elektrokroma fönster har störst potential i energibesparing i varma klimat.   Detta förklarar den minimala skillnaden av byggnadens påverkan mellan städer och scenarier. I denna rapport saknas specifika kostnader för elektrokroma fönster. Därmed baseras kostnadsuppskattningen på generaliseringar och antagande, där billigaste och dyraste alternativet undersökts. Om byggnaden har väl fungerande fönster och markiser, är det inte kostnadseffektiv att byta till elektrokroma fönster, då återbetalningstiden är alldeles för lång. Men om byggnaden stod mellan vanliga fönster och elektrokroma fönster i planeringsfasen kan det vara intressant att göra en noggrann analys. Enligt denna studie så sparar den Operativa Temperatur strategin ca. 6 333kr per år. Det skiljer ca 60 000kr mellan vanliga fönster med markiser, och elektrokroma fönster. Detta skulle ge en återbetalning inom 10 år förutsatt att energipriserna, energiförbrukningen samt valuta värdet är desamma. Därefter skulle fönstret minska utgifterna i form av sparad energi.   Slutsatsen är dock att elektrokroma fönster inte är nödvändiga i detta projektet från en Miljöbyggnads synpunkt, eftersom att det inte förbättrar byggnadsbetyget. Dessutom kvarstår osäkerheten med kostnader.

Most available techniques for predicting internal daylight illuminance do not take into account reflected sunlight, nor the fact that under clear sky conditions the direction of the illuminance is usually upwards, not downwards from the sky. The general goal of this study is to investigate the issue of predicting the internal illuminance from natural light in clear sky conditions. This includes the possibility of proposing a method based on the concept of the average daylight factor for use in sunny climates. This thesis is divided into eight chapters. After introducing the problem in Chapter One, Chapter Two is a literature review of problems associated with utilising natural light in sunny regions. Chapter Three is the statement of the problem and how it will be solved. Existing equations for finding the average daylight factor have one thing in common: they assume that the incident light on the window comes directly from an overcast sky or by external reflection from it. If any of these equations are to be used under clear sky conditions, or a new method is to be developed based on the same concepts, the sensitivity of average internal illuminance to the direction of external light needs to be tested. A study of this is described in Chapter Four. Chapter Five tests, by numerical simulation, the performance of existing average daylight factor methods under clear sky conditions. It is concluded that they are not appropriate for sunny regions. The tests, and the conclusions from Chapter Four, do, however, suggest a new approach. This has two bases. The first is that it has been shown to be possible to relate incident light on the window plane to horizontal sky illuminance, and this sets a minimum condition for window design. In practice this can be used in conjunction with a limiting maximum window size based on heat gain and other environmental issues. The second basis is a new formula for relating average internal illuminance to external window plane illuminance. The overall result is a formula for predicting internal illuminance as a ratio of external horizontal sky iluminance. In Chapter Seven this approach is tested. Two methods are used: field measurements under real sky conditions, and comparison with detailed calculations.

No description available.

Solar-control films are increasingly being retrofitted to the windows of buildings as a means of reducing solar gain. At present, there is a dearth of information concerning how these films effect the thermal comfort of occupants within buildings where these films have been applied. An illuminated hot box, utilising a xenon lamp to simulate sunlight, has been designed as a testing facility. The illuminated hot box has been used to obtain information on how much thermal radiation enters the internal space from a window fitted with a solar-control film. The data from the experimental apparatus was verified using a finite-difference model written on a personal computer, with the aim of the computer program being used to compare different films, and thereby avoiding expensive experiments. The experimental rig produced usable data for the tested films only when the lamp was orthogonal to the plane of the glass, with errors occurring, and increasing, as the angle of incidence between the lamp and the glass increased. This conclusion was verified by the computer based model. It was seen that the illuminated hot box was too small to give accurate measurements for angles of incidence other than 0°. It is suggested that a larger illuminated hot box which is able to eliminate the problems encountered when measuring for angles of incidence above 10° would be desirable. Furthermore, a more complex transient finite-difference computer based simulation model is needed, taking into account the conclusions that were made during this study.