Device driver is an important part of an operating system. All I/O device accesses must be done through device drivers. Because they reside in the kernel address space, a driver fault may lead to a system failure, which is not acceptable for embedded systems with high dependability requirements. Many embedded systems execute safety-critical tasks and hence a system failure will cause a great loss. Running drivers in user mode can prevent the drivers from damaging the operating system kernel. User mode driver resulted in a large performance degradation when it was proposed during the 1980s. Nonetheless, the performance has been improved due to good implementations of system call and context switch. According to the previous study, the performance of a user mode driver for a Gigabit network card can achieve 93% of that of the kernel mode driver in a Linux-based platform. Although the performance of user mode drivers has been improved, there is still a crucial problem which handicaps user mode drivers from being utilized widely. That is, drivers have to be modified in order to support a given user mode driver framework. In this thesis, we propose a user mode driver framework, which allows a kernel mode driver to be executed in the user space without any code modifications. The framework emulates the kernel-space execution environment in the user space, In this framework, communication between user mode driver process and the kernel is done through I/O request redirection and shared memory. We implemented the framework on an ARM Linux based embedded system platform. The prototype of our framework supports two classes of user mode drivers: character device drivers and network interface drivers. The former includes a LED and a 7-segment user mode device drivers, and the latter consists of an Ethernet user mode device driver. Our work has two contributions. First of all, we enable direct execution of kernel mode drivers in the user space without any driver code modifications.. Second, we evaluate the performance of user mode drivers in an embedded system. To the best of our knowledge, no results about performance of user mode drivers on embedded systems have been reported. According to the experimental results, the performance of our user mode drivers can achieve 61%~99% of that of the kernel mode ones. This demonstrates that the framework we propose can improve the reliability of system under the acceptable costs of performance.

Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep wake cycles normally [1]. Narcoleptic patients feel overwhelmingly tired and sleepy. They do not have the ability to carry out normal day time activities, such as work or study, hence proper treatment is essential. In order to provide an accurate diagnosis of the sleep disorder, physicians must analyze the sleep stages of the patient. Sleep staging analysis is the process of extracting sleep information with brain signals known as electrophysiological signals. There are three major electrophysiological signals: Electroencephalograms (EEG), Electro-oculograms (EOG), and Electromyograms (EMG). Through the three signals, physicians and technicians can classify the sleep stages. Although all three signals are important, most physicians and researchers agree that 95% of information can be extracted from EEG signal. With the current technology, patients must go to the hospital and sleep there over night to perform the sleep stage studies. Electrodes are placed on their scalp, eyelids and skin for this examination. Often patients feel that it is very inconvenient and time consuming. Moreover, the technicians are prone to make human errors during the classification of the sleep stages. These errors are a result of fatigue that the technicians experience while doing the long process of classification of the sleep stages, and the complexity and ambiguity of the rules to determine the sleep stages. Our research group has worked together to construct a portable device that will provide advice to the narcolepsy patient for activity planning and medication dosage. In addition, it provides fore-warning to the patients prior to an narcoleptic attack. This device will also perform real-time sleep analysis and alertness assessment through processing of electroencephalogram (EEG) signal. The classification accuracy is extremely important to the development of this device. With high accuracy of the classifier, treatment for the patients can be determined more accurately by the physicians. As a result, the main purpose of the research presented in this thesis is to analyze different classification methodology and to optimize the parameters of each technology to obtain the optimal sleep stage classification results. The thesis will also present the description of the portable device and its components used for the development of the prototype.

The parallel bars is used in physical therapy and is mainly used for patients who have to train walking and balance after a stroke or an operation. It consists of two long handrails with two legs on each handrail. These legs go down into two ground-plates and are locked at the wanted height with a pin. The parallel bars is an appreciated device and is used on a daily basis in many care units. The main issue with the manual parallel bars is that it is very difficult and heavy for a single person to adjust the height of it. If a larger adjustment of the height has to be done, the legs have to be adjusted one at a time otherwise the they will be locked. Often the height isn’t adjusted after every single patient because it’s so difficult and therefore the training doesn’t get optimal for patient. The purpose with this project has been to find a solution that makes the height easier to adjust, so that the parallel bars will be adjusted after each patient. Our goal was to develop and produce a functional prototype of the solution. The result was Levo which is a lifting device that complements the parallel bars. Levo is a simple product to handle and has wheels which makes it easy to move around. To adjust the height of the parallel bars with Levo, place Levo in the middle of the handrail and press the button. The handrail will go up and the button can be released when the right height is reached. To lower the handrail, press the button and push the handrail down. Release the button when it has reached the wanted height. Levo has a construction which makes it possible to use as a complement to almost every manual parallel bars on the market. For a product to be used in care units it has to meet special demands. To know which demands and what properties Levo had to fulfill to be a product that physiotherapists could use and wanted in their work, we contacted several physiotherapists. For example the product could not have any sharp edges and had to be easy to clean. The product also had to be easy and fast to use when the height of the parallel bars should be adjusted. The physiotherapists point of view was in consideration during the developing process of Levo and many different solutions was compared to find an optimal solution that fulfilled all the demands. / Den manuella gåbarren är ett hjälpmedel inom sjukgymnastiken för att träna patienter i gång och balans. Barren är uppbyggd av två långa ledstänger med två ben på vardera ledstång. Dessa ben sitter fast i varsin bottenplatta som håller ihop barren på bredden och hindrar den från att välta. Gåbarren är ett uppskattat hjälpmedel och används på de flesta sjukgymnastikenheter inom sjukvården i Sverige. För att kunna reglera höjden på ledstängerna efter patientens behov behöver vårdpersonalen lösgöra benen i bottenplattan samt lyfta ledstången till önskat läge för att sedan låsa benet i det läget. När barren behöver justeras flera höjdlägen behöver arbetet göras stegvis på alla ben då benen annars låser sig för varandra. Eftersom arbetet med att justera höjden på barren är tungt och tidskrävande slarvas det ofta med att anpassa höjden efter varje patient. Detta i sin tur kan bli ett problem för patienten som inte får en optimal träning i barren. Syftet med projektet är att hitta en lösning till problemet med höjdjusteringen som gör det enkelt för vårdpersonalen att justera höjden för varje patient. Målet är att ta fram en fungerande prototyp på lösningsförslaget. Resultatet blev produkten Levo som är en separat lyftanordning till gåbarren. Levo är en smidig och lättanvänd produkt som är enkel att flytta till barren då den har hjul. Levo används genom att den placeras under barrens ena ledstång och höjden på Levo justeras med hjälp av en knapp. Önskas ledstången att höjas hålls knappen inne tills rätt höjdnivå uppnås. Skall ledstången sänkas hålls knappen inne tills rätt höjd har nåtts samtidigt som personen trycker ner ledstången. Fördelen med Levo är att den utför det tunga arbetet med att lyfta barren, samtidigt som den inte är i vägen för patienten eftersom den enkelt kan flyttas undan efter användning. Den har inget behov av eluttag eller liknande eftersom lyftmekanismen i är en gasfjäder som inte kräver någon skötsel. Under arbetet med att ta fram Levo intervjuades sjukgymnaster för att få en uppfattning om vilka egenskaper och krav som produkten behöver uppfylla för att den ska få användas inom sjukvården, samt vara tilltalande för personalen. Den får till exempel inte ha vassa kanter och måste vara lätt att rengöra. En annan viktig del är att den måste vara lätt att använda och det skall gå snabbt att justera höjden på barren med den, annars är risken stor att den inte användas. Detta togs hänsyn till under framtagningen av Levo där flera olika typer av lyftmekanismer jämfördes för att hitta en optimal lösning som uppfyllde sjukgymnasternas krav.

The project contains a force analysis of the vertical axis wind turbine Lucia's supporting arms and a measuring device to experimentally measure the forces is made. The forces between the supporting arms and the tower are calculated theoretically and then simulated by a computere. A measuring devise is then designed to measure the forces experimentally. The forces acting on the attachment between the supporting arms and the tower is primarily the centripetal force, gravitational force and the aerodynamic forces on the rotor wings. The maximum forces were theoretically calculated and is 13.38 kN along the x-axis, -0.25 kN along the y-axis and then 0.5 kN along the z-axis. The axis are acording to a rotational reference system where the x-axis runs along the supporting arm and the y-axis runs along the axis of rotation. The maximum torque that occurs is 0.53 kNm along the y-axis and 1.29 kNm along the z-axis. The size of the forces have been confirmed with a deviation of up to 1.8 % in the simulation using SolidWorks 2010. For the experimental measurements a measuring device has been developed which consists of S-load cells with wave indicator and transmitter, an attachment for the measuring equipment and distanceplates to stabilize the rotor. S-load cells, wave indicator and transmitter were ordered and drawings for the attachment of the measuring equipment and spacer plates was done. The eigenfrequencies and the stress have been investigated for the parts. The eigenfrequencies for the wind turbine was estimated to decline up to 13 % when the measuring device was mounted and the lowest Factor of Safety was 1.67. Before the attachment of the measuring device and the spacer plates can be ordered the attachment of the supporting arms, how the loadcells should be attached to the device and the safety margins need to be examined.

Our task was to create a virtual test bench for verifying memory addresses in our commissioning body’s models. The purpose with the testbench was that it should be created in such a way that it would be easy to change the device under test without any major changes in the testbench. To solve the problem that the testbench had to be able to verify different devices we had to create a general enviroment for how the testbench had to be composed. By doing an analysis of which com-ponents that are usually included in a testbench and which components that were necessary in our project we came up with a generall enviroment for the testbench. Our result was a testbench with the follwing basic functions: * Read from a file that contains read and write operations to the Device Under Test (DUT).* Apply the stimulus to the device* Read the results from the device* Compare the results with wanted values* Generate a log file which contains information about the simulation result.

Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep wake cycles normally [1]. Narcoleptic patients feel overwhelmingly tired and sleepy. They do not have the ability to carry out normal day time activities, such as work or study, hence proper treatment is essential. In order to provide an accurate diagnosis of the sleep disorder, physicians must analyze the sleep stages of the patient. Sleep staging analysis is the process of extracting sleep information with brain signals known as electrophysiological signals. There are three major electrophysiological signals: Electroencephalograms (EEG), Electro-oculograms (EOG), and Electromyograms (EMG). Through the three signals, physicians and technicians can classify the sleep stages. Although all three signals are important, most physicians and researchers agree that 95% of information can be extracted from EEG signal. With the current technology, patients must go to the hospital and sleep there over night to perform the sleep stage studies. Electrodes are placed on their scalp, eyelids and skin for this examination. Often patients feel that it is very inconvenient and time consuming. Moreover, the technicians are prone to make human errors during the classification of the sleep stages. These errors are a result of fatigue that the technicians experience while doing the long process of classification of the sleep stages, and the complexity and ambiguity of the rules to determine the sleep stages. Our research group has worked together to construct a portable device that will provide advice to the narcolepsy patient for activity planning and medication dosage. In addition, it provides fore-warning to the patients prior to an narcoleptic attack. This device will also perform real-time sleep analysis and alertness assessment through processing of electroencephalogram (EEG) signal. The classification accuracy is extremely important to the development of this device. With high accuracy of the classifier, treatment for the patients can be determined more accurately by the physicians. As a result, the main purpose of the research presented in this thesis is to analyze different classification methodology and to optimize the parameters of each technology to obtain the optimal sleep stage classification results. The thesis will also present the description of the portable device and its components used for the development of the prototype.

IEEE 802.11 wireless networks are plagued with problems of unauthorized access. Left undetected, unauthorized access is the precursor to additional mischief. Current approaches to detecting intruders are invasive or can be evaded by stealthy attackers. We propose the use of spectral analysis to identify the type of wireless network interface card (NIC). This mechanism can be applied to support the detection of unauthorized systems that use NICs which are different from that of a legitimate system. We focus on two functions, active scanning and dynamic rate switching, required by the 802.11 standard that are implemented in the hardware and software of the wireless NIC. We show that the implementation of these functions influence the transmission patterns of a wireless stream that are observable through traffic analysis. Furthermore, differences in the behavior of a wireless stream caused by differences in the implementation of these functions are exploited to establish the identity of a NIC. Our mechanism for NIC identification uses signal processing to analyze the periodicity embedded in the wireless traffic caused by active scanning and rate switching. A spectral profile is created from the periodic components of the traffic and used for the identity of the wireless NIC. We show that we can discern between NICs manufactured by different vendors and NICs within the same manufacturer using the spectral profile.

In present dissertation, field-driven quantum well (QW) device is proposed to obtain high-speed and high-efficiency all-optical wavelength converter (AOWC). A new type QW material, InGaAsP/InGaAlAs, is employed to improve not only quantum confined Stark effect, but also carrier life time during high electric field excitation. The bandwidth as well as efficiency can be enhanced. Thus, the slow gain recovery mechanism (~100ps) from conventional semiconductor optical amplifier (SOA)-based AOWC can be overcome. The dispersion- and efficient- limited fiber-based AOWC (~10ps) can also be avoided. -3dB frequency bandwidth exceeding 40GHz for both electrical-to-optical and photocurrent response has been observed from InGaAsP/InGaAlAs waveguide of AOWC, leading to above 40GHz bandwidth in optical-to-optical response. A 40 Gb/s measurement setup is finally used for testing eye-diagram and bit-error-ratio in order to verify the data transmission of AOWC. Low power penalty with 0.5 dB comparing with back-to-back system performance is measured, suggesting InGaAsP /InGaAlAs waveguide is applicable to all-optical processing. By exciting short optical pump pulse in such waveguide, as short as 6.4ps probe pulse is observed, breaking through 10ps order in conventional type of QW and thus indicating the plausibility of performing 100Gb/s all optical processing.

Recently, ¡§Pyrene¡¨ is a well-known substitutive group because the rigid structure and hole-injection ability of pyrene units can improve the thermal and electronic properties of blue OLED materials. The aromatic ring of pyrene not only improves the thermal and hole-injection ability of derivatives, but also provides high photoluminescence (PL) efficiency and high carrier mobility. Through these characteristics we can understand that the electron-rich pyrene derivatives can enhance the properties of OLED device. In this study, we developed low-molecular-weight structures with spiro-type molecules based on 9,9-spirobifluorene and fabricated the OLED device with the structure of ITO(170 nm)/PEDOT:PSS(50 nm)/PVK:TPSBF (40%)(90 mm)/BPhen (30 nm)/ LiF(1 nm)/Al(200 nm). It exhibited a maximum luminance at 500 mA/cm2 of 4130 cd/m2 with the Commission Internationale de l'Eclairage (CIE) of (0.16 , 0.16), and the maximum current and power efficiency were 1.9 cd/A and 0.9 lm/W, respectively. We concluded that TPSBF has good emission efficiency according to device performances. The PL maximum of the thick film of TPSBF, prepared by vacuum vapor deposition appears broadband spectrum, that resulted from the aggregation of the pyrene moieties. From Atomatic Force Microscopy (AFM) results, we propose three emission mechanisms. 1. Intramolecular spectrum ¡÷ 450 nm 2. Molecular aggregation spectrum ¡÷ 500 nm 3. Longer conjugation spectrum of intermolecular ¡÷ 550 nm We could fabricate the organic white light emitting device with a single and thicker emitting layer TPSBF and the more broadband emitting spectrum can be obtained. Finally, we fabricated the organic white light emitting device with a structure of ITO(170 nm)/2T-NATA(15 nm)/NPB(65 nm)/TPSBF(50 nm)/Alq3(30 nm)/LiF(0.8 nm)/Al(200 nm). It exhibited a maximum luminance at 1300 mA/cm2 of 57680 cd/m2, the maximum current and power efficiency were 6.51 cd/A and 4.07 lm/W, respectively, and with good CIE coordinate of (0.29 , 0.36).

In this thesis, we design novel implantable antennas for medical implant communication systems and it could operate with the metamaterial which is the artificial electromagnetic (EM) cover layer. The metamaterial based matching layer placed on the surface of the body can improve the performance of the implantable antenna. First, we propose two layers and three layers antenna design. The three layers antenna features high tolerance, high gain, low-profile and miniaturization. The antenna achieves gain −21.7 dBi and efficiency 0.2%. Compared with other literatures of implanted antenna design, the proposed three layers antenna reveals the best gain with similar dimensions. Furthermore, its frequency response is insensitive to the change of the implanted environment. The conception of impedance matching is applied to further improve the gain of the proposed antenna. The matching layers are realized by utilizing the metamaterial and it is placed between the body and the air. In this case, the gain of the three¡Vlayer antenna can be enhanced by 1.23¡V5.2 dB. Furthermore, we propose a size reduction technique to reduce the thickness of the matching layer. The miniature matching layers can increase the gain of the three¡Vlayer antenna by 1.64 dB and 2.63 dB with the dimension of 40¡Ñ40¡Ñ4mm³ and 60¡Ñ60¡Ñ4mm³ respectively. Finally, we propose a co¡Vdesign method of the antenna and metamaterial. The antenna will resonate after placing metamaterial on the surface of the body. So that we can control the antenna whether to transmit power or not by the circuit design in the biomedical device to detect the return loss of the antenna.