The current study evaluates the effectiveness of a Brain-Computer Interface (BCI) system that operates by detecting a P300 elicited by one of four randomly presented stimuli (i.e., YES, NO, PASS, END). Two groups of participants were tested. The first group included three ALS patients that varied in degree of disability, but all retained the ability to communicate; the second group included three Non-ALS controls. Each participant participated in ten experimental sessions during a period of approximately 6 weeks. Sessions were conducted either at the participant's home or in the lab. During each run the participant's task was to attend to one stimulus and disregard the other three. Stimuli were presented auditorily, visually, or in both modes. Additionally, on each run, the experimenter would either tell the participant which stimulus to focus on, or ask the participant a question and the participant would focus on the correct "YES/NO" answer to the question. Overall, for each participant, the ERPs elicited by the target stimuli could be discriminated from the non-target stimuli; however, less variability was observed in the Non-ALS group. Comparing across sessions, the within session variability was lower than across session variability. In addition, waveform morphology varied as a function of the presentation mode, but not in a similar pattern for each participant. Offline and simulated online classification algorithms conducted using step-wise discriminant analysis produced results suggesting the potential for online classification performance at levels acceptable for communication. Future investigations will begin to focus on testing online classification performance with real-time feedback, and continuing to examine stimulus properties to determine how to maximize P300 amplitude for individual users.

<p>POTS (Plain Old Telephony Service) systems have traditionally been connected via synchronous connections. When installing new nodes in the telephone network, they may sometimes be connected via packet networks such as Ethernet. Ethernet is an asynchronous network which means that nodes connected to the network don’t have access to the same clock frequency if it is not provided in some other way. If two nodes have different clock frequency, the receiver’s buffer will eventually overflow or starve. While not being a severe problem for telephony, devices used for data transmission, e.g. modems and fax will not be able to function properly. To avoid this it is necessary to synchronize the nodes.</p><p>This thesis investigates methods to synchronize nodes connected over Ethernet by simulating them in Matlab. The simulations show that under certain circumstances it is possible to produce a clock signal conforming to relevant standards.</p>

As Moore���s Law continues to give rise to ever shrinking channel lengths, circuits are becoming more digital and ever increasingly faster. Generating high frequency clocks in such scaled processes is becoming a tough challenge. Digital phase locked loops (DPLLs) are being explored as an alternative to conventional analog PLLs but suffer from issues such as low bandwidth and higher quantization noise. A digital multiplying delay locked loop (DMDLL) is proposed which aims at leveraging the benefit of high bandwidth of DLL while at the same time achieving the frequency multiplication property of PLL. It also offers the benefits of easier portability across process and occupies lesser area. The proposed DMDLL uses a simple flip-flop as 1-bit TDC (Time Digital Converter) for Phase Detector (PD). A digital accumulator acts as integrator for loop filter while a ��-�� DAC in combination with a VCO acts like a DCO. A carefully designed select logic in conjunction with a MUX achieves frequency multiplication. The proposed digital MDLL is taped out in 130nm process and tested to obtain 1.4GHz output frequency with 1.6ps RMS jitter, 17ps peak-to-peak jitter and -50dbC/Hz reference spurs. / Graduation date: 2012

The design of high-performance, high-speed clock generation and distribution becomes challenging in terms of phase noise, jitter and power consumption, due to the fast development of communication and computing systems. Injection locking is a promising clocking technique since it can significantly improve the energy efficiency, suppress the phase noise of the ring oscillator, enable a fast startup and conveniently generate multiple time-interleaved phases. A quasi-linear model of injection-locked ring oscillator (ILRO) is utilized to mathematically formulate the frequency and time domain characteristics of the system, as well as the phase noise shaping and jitter tracking behavior. The settling behavior of ILRO is also exploited and shows a strong dependence on the locking range and the initial phase difference of the injected and the resultant oscillation signals. A forwarded-clock synchronization based on injection locking is designed for a 10 Gb/s photonic interconnect according to the specific features of optical links. A single clock recovery can be used for all the four channels, resulting in a large amount of power and area saving. The applications of sub-harmonic and super-harmonic injection locking in wireless communications for frequency multiplying and division are also discussed. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Oct. 1, 2012 - Oct. 1, 2014

To work and live in the same place where ones employer also is the landlord, can create a situation with many special requirements for the individual. Constrains regarding time, space and impact on social life is likely to appear. Based on theory and empirical research about the Boundaryless work and the Psychological contract the purpose of this report is to examine employees who live and work at the same place. This is done by studying the regulation regarding time and space factors and the psychological contracts in expectations and in violation of the psychological contract and the risks associated with this like Locked-in factors. The study includes interviews with managers and employees (n=9). The result shows the difficulties to set standards for the constrains of the factors concerning time and space. The expectations from both employees and the organization goes beyond what can be considered as formal work boundaries. The results are discussed in relation to the risks of stress, health and Lock-in.

The general aim was, within psychiatric inpatient care, to explore patient and staff perceptions with regard to medication administration and locked entrance doors. In Study I, medication administration was illuminated according to a mini-ethnographic approach. Nurses and voluntarily admitted patients were observed and interviewed. Two central categories of patient and nurse experiences were identified, get control and leave control. In Study II, patients and nurses were interviewed about patient experiences of forced medication. Identified experiences were related to the disease, being forcibly medicated, and the drug. In Study III, the frequency of and reasons for locked entrance doors on Swedish psychiatric inpatient wards were investigated. Seventy three per cent of the doors were locked on a specific day. According to ward managers, doors were most often locked in order to prevent patients from escaping, provide security and safety, and because legalisation. In Study IV/V, voluntarily admitted patients/mental nurse assistants and nurses were interviewed about advantages and disadvantages about being cared for/working on a psychiatric inpatient ward with a locked entrance door. Most advantages mentioned by patients and staff were categorised as protection against “the outside”, secure and efficient care, and control over patients. Most disadvantages mentioned by patients were categorised as confinement, dependence on the staff, and emotional problems for patients. Most disadvantages mentioned by staff were categorised as extra work, confinement, dependence on the staff, and a non-caring environment. In conclusion, medication administration and locked entrance doors are perceived as connected with staff’s control and restricted freedom for patients. Increased reflection among staff about how medication administration and locked entrance doors are perceived by patients would increase staff’s possibilities to prevent potential experiences of coercion due to these situations among patients in psychiatric inpatient care.

Phase Locked Loops(PLLs) are an integral part of almost every electronic system. Systems involving low frequency clocks often require PLLs with low bandwidth. The area occupied by the large loop filter capacitor and resistor in a low bandwidth PLL design makes the realization of traditional charge-pump PLL architecture impractical on a single die, mandating external components on the board. In order to maintain low loop bandwidth the designer is often forced to choose very low values of charge pump current which can lead to reliability issues. In this work, a semi-digital architecture for very low bandwidth monolithic PLLs is proposed. This architecture eliminates large components in traditional charge-pump PLL, thus allowing the realization of on-chip low bandwidth PLLs. A 2x2mm PLL is realized in 180nm CMOS with 75mHz bandwidth consuming 400μW power from 1.8V supply. The prototype PLL locks to an input clock of 1Hz and generates 20kHz output clock with a measured peak-to-peak jitter of 100ns. / Graduation date: 2013

A brain-computer interface (BCI) allows individuals to communicate through the modulation of regional brain activity. Clinical near-infrared spectroscopy (NIRS) is used to monitor changes in cerebral blood oxygenation due to functional activation. It was hypothesized that visually-cued emotional induction tasks can elicit detectable activity in the prefrontal cortex. Data were collected from eleven participants as they performed positively and negatively-valenced emotional induction tasks. Baseline and activation trials were classified offline with accuracies from 75.0-96.7% after applying a feature selection algorithm to determine optimal performance parameters for each participant. Feature selection identified common discriminatory features across participants and relationships between performance parameters. Additionally, classification accuracy was used to quantify NIRS hemodynamic response latency. Significant increases in classification rates were found as early as 2.5 s after initial stimulus presentation. These results suggest the potential application of emotional induction as a NIRS-BCI control paradigm.

Size reduction processes, particularly fine grinding systems, in mineral processing and cement production plants constitute a great portion of energy consumption and operating costs. Therefore, the grinding systems should be designed properly and operated under optimum conditions to achieve productive and cost effective operations. The use of simulation based on kinetic mathematical models of grinding has proven useful in this respect. The kinetic models contain two essential parameters, namely, breakage rate and breakage distribution functions, that are to be determined experimentally, and preferably in laboratory, or by back-calculation from the mill product size distribution for a given feed size distribution. Experimental determination of the breakage parameters has been mostly carried out in laboratory batch mills using one-size-fraction material. The breakage rate parameter is obtained from the disappearance rate of this one-size-fraction material, while the breakage distribution parameters are estimated from the short-time grinding of the same material. Such laboratory methods using one-size fraction material, however, are not truly representative of industrial continuous mill operations where the mill contents have a distribution of particle sizes. There is evidence in the literature that the size distribution of the mill contents affects the breakage parameters. This thesis study was undertaken with the main purpose of investigating the effect of the size distribution of the mill hold-up on the brekage parameters of quartz and calcite minerals in lockedcycle dry grinding experiments. The locked-cycle and one-size-fraction experiments were performed in the Bond ball mill instrumented with a torque-measuring device. Different closing screen sizes were used in the locked-cycle work to produce different size distributions of the mill hold-up, and the operating conditions were changed in the one-size-fraction experiments to obtain different power draws. Particle breakage parameters were assessed for these changing conditions. Prior to the experiments related to the main purpose of the study, preliminary experiments were conducted for two reasons: (i) to find the power draw of the Bond mill in relation to the operating conditions with the intention of eliminating the use of costly torque-measuring devices by others / and (ii) to find the most accurate estimation method of breakage distribution functions among the three existing methods, namely, the &ldquo / zero-order production of fines&rdquo / method, the BII method, and the G-H method. The G-H method was found to be more appropriate for the current study. The locked-cycle grinding experiments revealed that the breakage rate function of coarse fractions increased with increasing proportion of fines in the mill hold-up. Breakage distribution functions were found to be environment-dependent and non-normalizable by size in one-size-fraction and locked cycle grinding experiments. It was concluded that the cumulative basis breakage rate function could sufficiently represent the breakage characteristics of the two studied materials in a wide range of operating conditions. Therefore, it would be more appropriate to evaluate the breakage characteristics of materials ground in ball mills by linearized form of the size-discretized batch grinding equation using single parameter instead of dealing with two parameters which may not be independent of each other.

A brain-computer interface (BCI) allows individuals to communicate through the modulation of regional brain activity. Clinical near-infrared spectroscopy (NIRS) is used to monitor changes in cerebral blood oxygenation due to functional activation. It was hypothesized that visually-cued emotional induction tasks can elicit detectable activity in the prefrontal cortex. Data were collected from eleven participants as they performed positively and negatively-valenced emotional induction tasks. Baseline and activation trials were classified offline with accuracies from 75.0-96.7% after applying a feature selection algorithm to determine optimal performance parameters for each participant. Feature selection identified common discriminatory features across participants and relationships between performance parameters. Additionally, classification accuracy was used to quantify NIRS hemodynamic response latency. Significant increases in classification rates were found as early as 2.5 s after initial stimulus presentation. These results suggest the potential application of emotional induction as a NIRS-BCI control paradigm.