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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Occupant responsive optimal control of smart façade systems

Park, Cheol-Soo 05 1900 (has links)
No description available.
2

Textila cylindrar : experiment kring solljusreglering / Experiment around sun control

Heurling, Julia January 2005 (has links)
Working with a three-dimensional shape that adjusts light seemed exciting. Venetian blinds became a basis and source of inspiration in my project. What is a Venetian blind? I arrived at the definition ”a surface of angleble pieces for sun adjustment”. From that simplified meaning I started making sketches of what an alternative model could look like. My sun shield consists of manual adjustable cylinders. The idea is that every adjustable piece, besides blocking sunlight, also can be a jig-saw-piece. Every cylinder has a simple décor on the blocking side. Depending on how the pieces are angled, different patterns are formed. The shadow effect will also be an adjustable pattern. My aim has been to make a prototype for alternative sun adjustment. Focus is on experiment with shape and user experience rather than technical perfection and efficiency. / <p>Program: Textildesignutbildningen</p><p>Uppsatsnivå: C</p>
3

Thermal modelling of highly glazed spaces

Pfrommer, Peter January 1995 (has links)
No description available.
4

Decision-Making Framework for the Selection and Design of Shading Devices

Olbina, Svetlana 11 March 2005 (has links)
Most shading device systems installed in windows or glass walls are used only for protection from overheating and glare, neglecting other possible functions, such as increasing the daylight level in the space or collecting solar energy. The blinds are usually made of opaque or translucent materials, and if they are partially open/closed or completely closed, a direct view to the outside is blocked. A balance between a sufficient amount of daylight and protection from overheating of the space in summer is not often achieved due to inappropriate control of the blinds’ tilt angle. There is also a need for specific guidance for the selection and design of shading device systems in the windows. This research develops a general decision-making framework (DMF) that can be used by architects and manufacturers of shading devices. The general DMF is a guide for the user in analyzing shading device performance in the process of selection/design of the shading device. This research also develops a specific DMF to better understand and validate the general DMF. The specific DMF, based on illuminance and luminance, is used for an analysis of daylighting performance of shading devices to select the best possible existing system or new system among several alternatives. Architects or manufacturers of shading devices, as the users of the DMF, analyze various systems of blinds applied on a particular building and at a given location. The users of the DMF can apply either an experimental procedure or computer simulation that provides information about illuminance and luminance levels in the space. Based on the analysis of the results of the experiments or simulations, the user of the DMF decides which blinds to select. The specific DMF proposes a methodology for both the analysis of the daylighting performance and for the process for making a decision based on the results of the analysis. A case study is conducted in order to validate the DMF. Three types of shading devices are tested: an existing system, a patented system, and a new system, proposed by this research. The shading devices are installed in an office space located in Roanoke, Virginia. The software Autodesk VIZ 4 is used to simulate daylighting performance. The output information, such as illuminance and luminance levels in the space, is used as a basis for making the decision about which type of blinds to apply. A new system of shading device, which has a triangular cross section and is made of clear plastic with a silver coating on one side, shows better performance than the existing shading device and the patented shading device, given the research limitations. By using the specific decision-making framework, a shading device manufacturer/designer is able to understand the shading device daylighting performance from his design-imposed criteria. Selection of the shading device, given the designer's daylighting objectives, is better achieved. Existing shading devices are also able to be analyzed from a building designer's perspective. This analysis is based on the designer-imposed daylighting criteria. The specific decision-making framework helps the designers of the buildings, together with the clients, select the most appropriate shading device based on daylighting performance. The decision-making framework is a model for development of decision-making software that will help designers of buildings, facades, and shading device systems in the selection/design of shading device systems in all phases of the design. / Ph. D.
5

Daylighting Systems : Development of Techniques for Optical Characterization and Performance Evaluation

Nilsson, Annica M. January 2012 (has links)
Successful integration of daylighting systems requires the ability to predict their performance for given climates. In this dissertation, a bottom-up approach is applied to evaluate the optical performance of a selection of daylighting systems. The evaluations are based on the optical properties of the included materials, and part of the dissertation focuses on developing new optical characterization methods. The work on characterization techniques uses an integrating sphere method to characterize the transmittance of light scattering samples more accurately. The method's principle is to reduce the discrepancy in light distribution between the reference and the sample scans by using an entry port beam diffuser. For samples exhibiting distinct light scattering patterns, the benefits of improved uniformity outweigh the errors introduced by the diffusing material. The method is applicable to any integrating sphere instrument, and its simplicity makes it suitable for standard measurements. In addition to normal-hemispherical properties, many daylighting applications require knowledge of the system's spatial light distribution. This dissertation presents a method combining experimental techniques and ray tracing simulations to assess the light distribution from a Venetian blind system. The method indicates that ray tracing based on simplified optical data is inadequate to predict the light distribution for slat materials exhibiting both specular and diffuse properties. Ray tracing is a promising complement to experimental methods used to characterize light guiding or light redirecting systems. Here, spectrophotometric measurements of a scaled mirror light pipe validate a ray tracing model. The model shows excellent agreement with experimental results for both direct and diffuse incident light. The spectral evaluation shows no dramatic color changes for the transmitted light. The ray tracing model is used to evaluate four daylighting systems for a selection of Swedish locations. The percentage of occupied time when the studied systems achieve full design illuminance is relatively low, but the systems provide a valuable contribution to the required illuminance. Additionally, this dissertation provides an overview of available energy efficient windows and illustrates the importance of including the solar energy transmittance when evaluating window energy performance. Overall, this dissertation presents optical characterization techniques for improved performance evaluations of daylighting systems.
6

Evaluating blind users’ accessibility to Facebook and Twitter pages of Örebro municipality.

Husnain, Ali January 2011 (has links)
Nowadays government departments and businesses use social networking sites to communicate with stakeholders. Notable reasons for this ongoing change are that the numbers of users on social networking sites have increased dramatically during the past ten years. Other reasons for utilizing social networking sites are that it is cost effective, more interactive due to Web 2.0 technology, as well as public demand. Besides increased interactivity and related benefits for normal users, this change emerged with accessibility problems for disabled users, especially when government departments utilize social networking sites. The adapted pages of these sites should be accessible for the disabled according to standards. Örebro municipality also utilizes social networking websites pages and this study provides an overview of the social networking sites’ accessibility to blind users. The study evaluated Örebro municipality’s Facebook and Twitter pages accessibility, by automatic evaluation tools against selected attributes of blind users’ accessibility metrics which are also the guidelines of W3C. The result of the study shows that there is more development required to make these pages completely accessible to blind users. However, the selected official website page of Örebro municipality was found completely accessible to blind users when evaluated for comparison, by the same automatic evaluation tools and selected guidelines.
7

Simulace vlivu zeměpisné orientace na letní klimatickou zátěž vysoce prosklených kancelářských prostor / Simulation of geographical orientation influence on summer solar gains in highly glazed office rooms

Soudek, Ondřej January 2011 (has links)
The thesis deals with simulation of solar gains in highly glazed administration building of Microsoft company on Vyskocilova Street in Prague. Effects of the geographical orientation and types of shading are compared on the base of the current simulation. For a more precise description of the effect of geographical orientation is simulation of solar gains in fictive office room with constant dimension together with applying different types of shielding. All the simulations are performed in TRSNYS 16.1 software.
8

Motorized control of a blind / Motoriserad styrning av rullgardin

Mauritzson, Samuel, Revilla, Fabian January 2019 (has links)
Automated solutions such as robotic vacuum cleaners and smart lighting are gaining popularity, both in the home as well as in public environments. The purpose of this project is to investigate the possibility of using a microcontroller to, in a user-friendly way, control a blind and to implement a sound sensor to activate the mechanism. A stepper motor was used to drive the blind and control its position. The prototype was programmed to recognize a sequence of two claps within a specific time interval. To make the prototype more user-friendly a UI was implemented with an LCD-display and mechanical buttons. A menu was designed where the user would be able to change settings such as the sound level threshold and motor speed as well as calibrate the position of the blind. The performance of the prototype was evaluated by testing the audio recognition by attempted activation in a quiet environment and by recording accidental activations in a loud environment. The conclusions drawn from these test were that the sound recognition was implemented and operated with a success rate of up to 73 %, but that it also triggered relatively easily by extraneous sound sources. Future improvements to this problem could include implementation of a band pass filter to further optimize the sound recognition to the desired audio cue. / Automatiserade lösningar som robotdammsugare och smart belysning blir allt mer populärt, både i hemmet och i offentliga miljöer. Syftet med detta projekt är att undersöka möjligheten att använda en mikrokontroller för att på ett användarvänligt sätt styra en rullgardin och implementera en ljudsensor för att aktivera mekanismen. En stegmotor användes för att driva rullgardinen och styra dess position. Mjukvaran formades för att känna igen en sekvens av två klappar inom ett visst tidsintervall. För att göra prototypen mer användarvänlig implementerades ett användargränssnitt med en LCD-skärm och mekaniska knappar. En meny utformades där inställningar som ljudnivåns tröskelvärde och motorvarvtal kunde ändras. Gardinens position kunde även kalibreras. Ljudigenkänningen utvärderades genom att testa aktivering i en tyst miljö och genom att registrera oavsiktliga aktiveringar i en högljudd miljö. Slutsatserna från dessa test var att ljudigenkänningen implementerades och fungerade konsistent vid upp till 73 % av aktiveringsförsöken, men att den också utlöstes relativt enkelt av yttre ljudkällor. Eventuella förbättringar av detta problem kan innefatta implementation av ett bandpassfilter för att ytterligare optimera ljudigenkänningen.
9

Hemautomation : Automatiska persienner för nedkylning

Olovsson, Jens January 2018 (has links)
Hur mycket värme strålar in genom fönster? Det beror på vilket håll de är vända mot och deras storlek. I den här rapporten jämförs två metoder för att hindra en temperaturhöjning. Den ena metoden är med luftvärmepump som jämförs kostnadsmässigt med den andra metoden som är automatiska persienner. Beräkningen av vad det kostar att kyla bort värmen med värmepump sker i MATLAB. Styrningen av persiennerna sker i det här fallet med hjälp av KNX. Kommunikationen sker via en buss. För att programmera styrningen används ETS5. Beräkningarna grundas på antagen att byggnaden har 8 m² fönster i sydlig riktning, 5 m² i östlig riktning och 4 m² i västlig riktning. Den tillförda värmen över hela året antas vara 10 000 kWh. Beräkningen tar inte hänsyn till yttertemperatur och är därför lite missvisande. Mätdata för antal soltimmar hämtas från SMHI för att beräkna solinstrålningen genom alla fönster. Med hjälp av denna information beräknas kostnaden att kyla bort solinstrålningen till 460 kr per år. Inköpspriset för luftvärmepumpen är 20 350 kronor. Priset för en persienn är 10 000 kronor. Författaren rekommenderar luftvärmepumpen för nedkylning av byggnaden i detta fall. / How much heat radiates in through windows? It depends on their direction and the size of them. Two methods to prevent a temperature increase are compared in this report. The first method is by removing the heat with a heat pump, which is compared to the second method that involves automatic blinds. The cost to run the heat pump to remove the heat is calculated in MATLAB. The control of the blinds in this case is with KNX. The communication is done through a bus. ETS5 was used to program the blinds. The calculations assume that the size of the southern windows are 8 m², the east-facing windows are 5 m², and the west-facing windows are 4 m². The added heat is assumed to be 10 000 kWh throughout the year. The calculations does not take outside temperature into account. Data for the amount of sunshine is taken from SMHI. With the help of this information the cost of cooling the radiated heat is calculated to 460 swedish crowns per year. The cost of buying the heat pump is 20 350 swedish crowns. One blind costs 10 000 swedish crowns to buy. The author recommends the heat pump to cool the building in this case.
10

An Adaptive Intelligent Integrated Lighting Control Approach for High-Performance Office Buildings

January 2015 (has links)
abstract: An acute and crucial societal problem is the energy consumed in existing commercial buildings. There are 1.5 million commercial buildings in the U.S. with only about 3% being built each year. Hence, existing buildings need to be properly operated and maintained for several decades. Application of integrated centralized control systems in buildings could lead to more than 50% energy savings. This research work demonstrates an innovative adaptive integrated lighting control approach which could achieve significant energy savings and increase indoor comfort in high performance office buildings. In the first phase of the study, a predictive algorithm was developed and validated through experiments in an actual test room. The objective was to regulate daylight on a specified work plane by controlling the blind slat angles. Furthermore, a sensor-based integrated adaptive lighting controller was designed in Simulink which included an innovative sensor optimization approach based on genetic algorithm to minimize the number of sensors and efficiently place them in the office. The controller was designed based on simple integral controllers. The objective of developed control algorithm was to improve the illuminance situation in the office through controlling the daylight and electrical lighting. To evaluate the performance of the system, the controller was applied on experimental office model in Lee et al.’s research study in 1998. The result of the developed control approach indicate a significantly improvement in lighting situation and 1-23% and 50-78% monthly electrical energy savings in the office model, compared to two static strategies when the blinds were left open and closed during the whole year respectively. / Dissertation/Thesis / Doctoral Dissertation Architecture 2015

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