Examensarbetet utfördes självständigt av Cecilia Edlund som studerar på Högskoleingenjörsprogrammet i innovationsteknik och design vid fakulteten för teknik- och naturvetenskap på Karlstads universitet. Arbetet utfördes under vårterminen 2012 och omfattade 22,5hp.   Uppdragsgivaren har varit Nokalux AB som utvecklar och producerar inomhus- samt utomhusbelysning för den professionella marknaden i Norden. Företaget har ett behov av att utöka sitt produktsortiment på utomhusmarknaden. Vilket har resulterat i uppdraget att utveckla en parkarmatur med LED-teknik som ljuskälla. Fokus i examensarbetet har varit förstudien. Detta för att grundligt ta reda på information kring LED och belysningsteknik som anses betydande vid utformning av utomhusarmaturer. Vidare fokuserades förstudien på vad som önskas på marknaden samt vad som är viktigt för brukarna för att översätta dessa attribut till en produkt. Genom idégenereringsprocessen togs olika koncept fram vilket presenterades för handledaren Erik Kihlgren på Nokalux AB. Tillsammans med företagets önskemål, krav samt elimineringsverktyg återstod två koncept. Dessa koncept utvecklades och utvärderades genom CAD-modellering och verkstadsmodeller för att slutligen resultera i en produkt. Produkten som har tagits fram består av en uppåtriktad ljuskälla som med hjälp av en reflektor riktar ner ljuset till marken. Reflektorn består av tio vinklade hexagonmönster som sprider ljuset på ett mjukt och behagligt sätt för brukaren. Det är en produkt som löser viktiga problem kring utomhusbelysning samtidigt som den är unik på marknaden. Vid konceptutveckling visualiserades produkten genom CAD-modellering, prototyper och grafiska illustrationer. Konceptvalet innefattar således ett förslag på utformning och montering av teknikens olika komponenter. / The thesis was conducted independently by Cecilia Edlund, a student at the Bachelor program in Innovation and Design Engineering within the Faculty of Technology and Science at Karlstad University. The thesis was conducted during the spring term of 2012 and contained work corresponding to 22,5hp.  The initiator of the project was Nokalux AB, which develop and manufacture indoor and outdoor lighting products for professional use in the Nordic market. The company has a need to expand their product line for outdoor use. Which resulted in the assignment to develop a new urban lighting fixture with LED as light source.    The focus of the project was in the feasibility study. For the purpose to thoroughly find information about LED and lighting technologies required in the design of outdoor lighting products.  Further focus was made to investigate the market demands and attributes that are important for the user and translate these into a product.  Through the process of concept compilation different ideas were presented to the mentor Erik Kihlgren at Nokalux AB. Along with the company’s point of view and elimination tools, two concepts remain at the end of the project. These concepts were developed and evaluated using CAD modeling, mockups and another elimination tool to finally result in one final product. The developed product consists of an upwardly directed light source that by the means of a reflector is directed to the ground. The reflector consists of ten angled hexagon patterns that distribute the light in a gentle and relaxing way for the users. It is a product that solves important problems concerning urban lighting as well as being unique in the market. Thru the concept development the product was visualised using CAD modelling, prototypes and graphic illustrations. The concept choice thus consisted of a proposal for the design and installation of technical components.

Reinforced concrete poles are commonly used as street lighting and electrical transmission poles. Typical concrete lighting poles experience very little load due to torsion. The governing design loads are typically bending moments as a result of wind on the arms, fixtures, and the pole itself. The Canadian pole standard, CSA A14-07 relates the helical reinforcing to the torsion capacity of concrete poles. This issue and the spacing of the helical reinforcing elements are investigated. Based on the ultimate transverse loading classification system in the Canadian standard, the code provides a table with empirically derived minimum helical reinforcing amounts that vary depending on: 1) the pole class and 2) distance from the tip of the pole. Research into the minimum helical reinforcing requirements in the Canadian code has determined that the values were chosen empirically based on manufacturer’s testing. The CSA standard recommends two methods for the placement of the helical reinforcing: either all the required helical reinforcing is wound in one direction or an overlapping system is used where half of the required reinforcing is wound in each direction. From a production standpoint, the process of placing and tying this helical steel is time consuming and an improved method of reinforcement is desirable. Whether the double helix method of placement produces stronger poles in torsion than the single helix method is unknown. The objectives of the research are to analyze the Canadian code (CSA A14-07) requirements for minimum helical reinforcement and determine if the Canadian requirements are adequate. The helical reinforcement spacing requirements and the effect of spacing and direction of the helical reinforcing on the torsional capacity of a pole is also analyzed. Double helix and single helix reinforcement methods are compared to determine if there is a difference between the two methods of reinforcement. The Canadian pole standard (CSA A14-07) is analyzed and compared to the American and German standards. It was determined that the complex Canadian code provides more conservative spacing requirements than the American and German codes however the spacing requirements are based on empirical results alone. The rationale behind the Canadian code requirements is unknown. A testing program was developed to analyze the spacing requirements in the CSA A14-07 code. Fourteen specimens were produced with different helical reinforcing amounts: no reinforcement, single and double helical spaced CSA A14-07 designed reinforcement, and single helical specimens with twice the designed spacing values. Two specimens were produced based on the single helical reinforcement spacing. One specimen was produced with helical reinforcement wound in the clockwise direction and another with helical reinforcement in the counter clockwise direction. All specimens were tested under a counter clockwise torsional load. The clockwise specimens demonstrated the response of prestressed concrete poles with effective helical reinforcement whereas the counter clockwise reinforced specimens represented theoretically ineffective reinforcement. Two tip sizes were produced and tested: 165 mm and 210 mm. A sudden, brittle failure was noted for all specimens tested. The helical reinforcement provided no post-cracking ductility. It was determined that the spacing and direction of the helical reinforcement had little effect on the torsional capacity of the pole. Variable and scattered test results were observed. Predictions of the cracking torque based on the ACI 318-05, CSA A23.3-04 and Eurocode 2 all proved to be unconservative. Strut and tie modelling of the prestressing transfer zone suggested that the spacing of the helical steel be 40 mm for the 165 mm specimens and 53 mm for the 210 mm specimens. Based on the results of the strut and tie modelling, it is likely that the variability and scatter in the test results is due to pre-cracking of the specimens. All the 165 mm specimens and the large spaced 210 mm specimens were inadequately reinforced in the transfer zone. The degree of pre-cracking in the specimen likely causes the torsional capacity of the pole to vary. The strut and tie model results suggest that the requirements of the Canadian code can be simplified and rationalized. Similar to the American spacing requirements of 25 mm in the prestressing transfer zone, a spacing of 30 mm to 50 mm is recommended dependent on the pole tip size. Proper concrete mixes, adequate concrete strengths, prestressing levels, and wall thickness should be emphasized in the torsional CSA A14-07 design requirements since all have a large impact on the torsional capacity of prestressed concrete poles. Recommendations and future work are suggested to conclusively determine if direction and spacing have an effect on torsional capacity or to determine the factors causing the scatter in the results. The performance of prestressed concrete poles reinforced using the suggestions presented should also be further investigated. Improving the ability to predict the cracking torque based on the codes or reducing the scatter in the test results should also be studied.

Taiwan lack natural and energy resource, need to import 99.3% energy. Due to the traditional high-carbon energy also supply from abroad, its supply will be impacted by international demand and production, price fluctuations, and the international politics. In recent years the international oil price surged upward, business costs were constantly raise. In this study, some small and medium businesses are taken as objects in Kaohsiung, Taiwan. In this investigation, understand the application of energy resource in those businesses, different industries have their attention to other items and differences, it can be seen on those small and medium enterprises in the concept and practice by measuring and computing power consumption. Research Methods: First, to explore the international and domestic energy and policy and the related energy research literature, interview the small and medium enterprises and observe the way of energy usage, and provide the improving solution, questionnaires and field measurements made on those enterprises, to record the response, investment willingness and problem for energy improving, statistical analysis and get the conclusion. The results showed that the prevalence among the small businesses¡¦ waste of energy, there is many invalid lighting, it is the room to improve the installation of reflective shade to effect the lighting, even replace the lamps (T8) to lamps (T5) with reflective shade, then reduce the use of lamps and power, indirectly to reduce the power consumption of air condition. This research also found there is considerable room to improve the light in the refrigerated cabinet. The traditional fluorescent lamps(T8) be used in the refrigerated cabinet. The performance is low and produce high temperature, then the refrigerated cabinet shall expand more power to reach the set temperature, if change those lamps to LED lamps could immediately reduce the loss of electricity bills. Extension of this study, there is a great improvement in the domestic building and enterprises on lighting application, it could reduce a lot of power consumption by detailed observing, detected, and improving engineer to remove lighting waste, and thus achieve carbon reduction targets by 20% of the electricity.

A flash lighting circuit with the fluorescent lamp is designed to produce lighting flicker by means of controlling the operating frequency and the duty-ratio of the lamp voltage and current. The intensity of the flash lighting is adjusted by the DC-link voltage of the electronic ballast circuit. The circuit structure is mainly composed of the class-D series-resonant inverter, the full-bridge rectifier, the LC filter and the commutation circuit. A control circuit with complex programmable logic device (CPLD) is used to accomplish the regulation of the operating frequency and the duty-ratio, which should be carefully controlled to ensure a stable lighting arc. In the meantime, a flash lighting detected circuit is designed to transform the flash lighting into a voltage signal. Experiment tests are conducted to human visual perception to demonstrate the applicability of the flash lighting circuit.

<p>This study appears to be one of few intervention studies with focus on eyestrain and lighting on non-computer workplaces. Previous studies have shown strong connections between eyestrain and musculoskeletal strain. The eyes “lead the body” and if the picture on the retina is unfocused the body adjusts the posture, trying to improve the image through changing the viewing distance. This can lead to an unnatural body posture which can contribute in the development of musculoskeletal disorders.</p><p>A good visual environment with proper illuminance, good luminance contrast relationship, good uniformity value of the illuminance and no glare are the best conditions in order to function well at a visually demanding work. Sorting mail is a task that needs good visual ergonomics and can therefore be improved by a change in the visual environment.</p><p>The overall purpose of this thesis is to investigate if a good visual environment have an impact on eyestrain, musculoskeletal strain, productivity, wellbeing, and work induced stress.</p><p>This thesis is based on a literature review and a lighting intervention, with one part before the intervention and two follow-up parts, summer and winter. The results are based on objectively measurements; lighting, time studies, and optometric eye examinations, and two questionnaires. The first questionnaire concerned visual ergonomics and the second had a focus on wellbeing and experience of work related tasks.</p><p>The postmen experienced the new lighting and labeling as improvement. A small decrease in the amount of eyestrain was present, and the younger postmen had a decrease of the musculoskeletal strain. The postmen with eyestrain got a small improvement of the sorting time. When the lighting was improved another factor that could cause strain appeared, the need for good correction in their glasses was identified as the main remaining factor that could cause the observed strain.</p> / Report code: LiU-Tek-Lic-2008:8.

No description available.

DEVELOPMENT AND RESEARCH OF SPECIAL LUMINAIRE SYSTEMS Relevance of the research When Lithuania were joined into the European Community it has become necessary to use lighting devices corresponding to requirements of the European Community – ENEC norms. Taking into account the specificity of given devices in Lithuania and other new EU countries they should be steady against low temperatures, humidity, acts of vandalism, to be suitable for the illumination of industrial buildings and to fulfil the requirements of low prices of the new incorporated countries. Recently new comprehensive ENEC norms (EN European Norms, EC Electrical Certification) for luminaires were drawn up and effectively introduced by the European Union. As a result, the production of a wide range of electrical operating equipment was discontinued due to the inconsistency between technical parameters of produced equipment and new norms. Such equipments were not allowed to be marketed. Therefore it has become necessary to develop luminaires capable to fulfil the increased quality requirements of the European Union. Their development should also taken into account due to the targets of product responsibility (§ 22) laid down in the Act for Promoting Closed Substance Cycle Waste Management and Ensuring Environmentally Compatible Waste Disposal introduced in 1996 also should be taken into account extensively the aspects of ecological efficiency. In the past, plastic luminaire systems belonging to a higher... [to full text]

DEVELOPMENT AND RESEARCH OF SPECIAL LUMINAIRE SYSTEMS Relevance of the research When Lithuania were joined into the European Community it has become necessary to use lighting devices corresponding to requirements of the European Community – ENEC norms. Taking into account the specificity of given devices in Lithuania and other new EU countries they should be steady against low temperatures, humidity, acts of vandalism, to be suitable for the illumination of industrial buildings and to fulfil the requirements of low prices of the new incorporated countries. Recently new comprehensive ENEC norms (EN European Norms, EC Electrical Certification) for luminaires were drawn up and effectively introduced by the European Union. As a result, the production of a wide range of electrical operating equipment was discontinued due to the inconsistency between technical parameters of produced equipment and new norms. Such equipments were not allowed to be marketed. Therefore it has become necessary to develop luminaires capable to fulfil the increased quality requirements of the European Union. Their development should also taken into account due to the targets of product responsibility (§ 22) laid down in the Act for Promoting Closed Substance Cycle Waste Management and Ensuring Environmentally Compatible Waste Disposal introduced in 1996 also should be taken into account extensively the aspects of ecological efficiency. In the past, plastic luminaire systems belonging to a higher... [to full text]

The human visual system has learned to assume that light originates from above, most likely because of the persistent natural overhead light source – the sun (Ramachandran, 1988). Asymmetries of perception in neurologically normal individuals, like assuming light is coming from above, in part result from efficiency measures of the visual system. Not only is light assumed to come from above, but light from above and to the left has been found to decrease reaction times in target finding as well as increase aesthetic preference (Sun & Perona, 1998; Smith & Elias, 2013). The underlying cause of the bias towards upper-left lighting is debated, and may have a relationship with another peculiar phenomenon in neurologically normal individuals where greater attention is paid to leftward space, called pseudoneglect (Bowers & Heilman, 1980). Alternatively, an explanation suggesting that directional reading influences lighting preferences has been proposed, as Smith and Elias (2013) found native right-to-left readers to be significantly different from leftward biased left-to-right readers. The current set of experiments used eye-tracking and a target finding paradigm to assess differences between left-to-right and right-to-left readers. Manipulating the position of the light illuminating a field of spheres generated targets, creating either 1 convex bubble among 15 concave depressions, or vice-versa. Results from these studies are mixed, and highlight differences between both upper and lower and lateral visual space. Light originating from above facilitated shorter average duration times for both groups, whereas left-to-right readers tended to prefer light from the upper-left, while right-to-left readers preferred light from the upper-right. No one target location in the array facilitated shorter average duration times for right-to-left readers, although left-to-right readers tended to exhibit shorter durations when identifying targets in the upper-left quadrant. Participants spent the greatest amount of time examining the upper quadrants of the array, tending to focus more on the side of the image that their native reading direction begins on. The influence of directional reading on light source perception, and the potential problems of using exclusively Western participant samples are discussed.

This work presents a new wireless Visible Light Communication lighting system targeted to future Smart Buildings. A digitally controlled LLC resonant dc-dc converter targeted to white LED luminaires is demonstrated. Visible Light Communication is implemented with minimal incremental cost, by operating the LLC converter in burst mode, without causing any visible disturbance. The converter operates with a regulated average LED current by adjusting the switching frequency, while the burst pulse timing is controlled to minimize the current disturbance and minimize the value of the output capacitor. Variable Pulse Position Modulation is used to modulate the data, while supporting a range of dimming settings. A digital demodulation scheme that supports variable frequency transmission is demonstrated. The 80 W, 400 V to 23 V converter experimental prototype has a peak efficiency of 93.8 %. The bit error rate of the complete system is fully characterized versus distance and angle.