During transport of hand-held objects, the grip force is modulated in parallel with the load force changes. The control scheme underlying this grip-load force coupling involves subtle interplay between feedforward and feedback mechanisms. Based on internal models of the motor system and object properties, the load force can be predicted and the GF motor command can be specified in a feedforward manner. Moreover, during the course of arm movement, the CNS is informed by sensory feedback about mechanical events such as the lift-off of the object, slippage or excessive grip force. This information is used to correct the motor commands and to update the internal model of the motor apparatus and object. In this thesis, three experiments were conducted to examine the relative contributions of sensory-driven and anticipatory control of GF adjustments during cyclic vertical movement with a hand-held load. The main point was to assess whether internal models underlying the grip-load force coupling are robust when the environmental context was changed or when the sensory feedback was suppressed. Two experiments in parabolic flight were conducted to study the effects of a change in gravity on the dynamics of prehension. The main perturbation was that the novice subjects applied unnecessarily high safety margins during their first trial at 0 and 1.8 g in order to secure the grasp insofar as the gravitational component of the load force was unpredictable. By contrast, the temporal coupling between GF and LF was maintained regardless of the gravity conditions because the inertial component of the load could be still predicted from the arm motor command (efference copy). In the second study performed during parabolic flight, we have observed that the subjects were able to exert the same grip force for equivalent load generated either by a change of mass, gravity or acceleration despite the fact that it requires different arm motor commands. These two experiments brought further evidence that the predictive mechanisms largely contribute to the GF adjustment. Static forces such gravity are taken into account in the motor plan allowing adequate motor command and precise prediction of the incoming load force change. The GF output would depend on the precision of this prediction that can be evaluatedonly after the movement onset through sensory information about the actual state of the system. The third experiment performed in this thesis studied the role of cutaneous afferents in object manipulation by anesthetizing the thumb and index finger. In addition to their phasic slip-detection function, the cutaneous afferents are required for setting the background level of the grip force. Actually, in absence of tactile feedback, the temporal coupling between the grip and load forces is maintained but the mean magnitude of GF progressively decreases leading to object slipping. It is hypothesized that accumulating error occurred in the LF prediction leading to inadequate level of GF. Cutaneous afferents are thus required to correct and maintain the internal model of the arm-hand object system.

During transport of hand-held objects, the grip force is modulated in parallel with the load force changes. The control scheme underlying this grip-load force coupling involves subtle interplay between feedforward and feedback mechanisms. Based on internal models of the motor system and object properties, the load force can be predicted and the GF motor command can be specified in a feedforward manner. Moreover, during the course of arm movement, the CNS is informed by sensory feedback about mechanical events such as the lift-off of the object, slippage or excessive grip force. This information is used to correct the motor commands and to update the internal model of the motor apparatus and object. In this thesis, three experiments were conducted to examine the relative contributions of sensory-driven and anticipatory control of GF adjustments during cyclic vertical movement with a hand-held load. The main point was to assess whether internal models underlying the grip-load force coupling are robust when the environmental context was changed or when the sensory feedback was suppressed. Two experiments in parabolic flight were conducted to study the effects of a change in gravity on the dynamics of prehension. The main perturbation was that the novice subjects applied unnecessarily high safety margins during their first trial at 0 and 1.8 g in order to secure the grasp insofar as the gravitational component of the load force was unpredictable. By contrast, the temporal coupling between GF and LF was maintained regardless of the gravity conditions because the inertial component of the load could be still predicted from the arm motor command (efference copy). In the second study performed during parabolic flight, we have observed that the subjects were able to exert the same grip force for equivalent load generated either by a change of mass, gravity or acceleration despite the fact that it requires different arm motor commands. These two experiments brought further evidence that the predictive mechanisms largely contribute to the GF adjustment. Static forces such gravity are taken into account in the motor plan allowing adequate motor command and precise prediction of the incoming load force change. The GF output would depend on the precision of this prediction that can be evaluatedonly after the movement onset through sensory information about the actual state of the system. The third experiment performed in this thesis studied the role of cutaneous afferents in object manipulation by anesthetizing the thumb and index finger. In addition to their phasic slip-detection function, the cutaneous afferents are required for setting the background level of the grip force. Actually, in absence of tactile feedback, the temporal coupling between the grip and load forces is maintained but the mean magnitude of GF progressively decreases leading to object slipping. It is hypothesized that accumulating error occurred in the LF prediction leading to inadequate level of GF. Cutaneous afferents are thus required to correct and maintain the internal model of the arm-hand object system.

Our thesis is made in collaboration with Autoliv Sweden and the department Global Development Seatbelt in Vårgårda. Autoliv was founded in 1953 by two brothers from Vårgårda. Since then, they have become world leading in automotive safety and cooperates with several major automotive companies.   The aim of the project was to evaluate a concept that Adrian Bud for Global Development Seatbelt department in Vårgårda had come up with. The concept aims to simplify the design and reduce the number of parts in an adaptive load limiter (LLA). With a reduction in the number of parts, the price for the LLA would decrease and also make assembly easier.   An LLA adjusts the chest compression from the seatbelt in a crash sequence. This helps reducing the injury that might result from such chest compressions in a crash. The load limiter ensures that the slowdown of the body is done in a smooth manner by adjusting the amount of belt released.   Our concept evaluation has included conceptual design, primary design, visualization of design in Catia V5 and FEM analysis. Finally prototypes were built with the help of Autolivs central workshop and tests were performed at Autoliv. The report also includes analyzes of the results, recommendations for the continuation of work and development and a critical review of the evaluation.

The aim of this study was to determine the combined effects of high-heeled shoes and load carriage on gait and posture adaptation. Furthermore, the adaptation of gait and posture to the combined two conditions was examined by a comparison of the measured parameters between experienced and novice groups. 30 participants underwent a quantitative measurement of temporospatial, kinematic, and kinetic parameters of hip, knee, and ankle on both loaded and unloaded limbs using 3D motion analysis. Double support time and stride length increased during high-heeled gait and the magnitude of alteration was greater with a load. Increased plantarflexion was main cause of raised heel. Ankle plantarflexor moment increased with high-heeled but decreased with load carriage. As a result, plantarflexor moment diminished, in addition knee extensor moment exaggerated further. Hip extensor moment increased with heel height but not with load weight, however, hip angle was affected only by the load.

With the popularity of outdoor activities like hiking, the demands of certain types of employment, or being a student, an individual’s ability to carry a load is an important mobility consideration. By understanding the changes to an individual’s gait when supporting a backpack load, an individual’s ability to carry heavy loads for prolonged periods could be improved. Most biomechanical studies have examined the changes in able-bodied gait when carrying a load. However, research is lacking on the effect of backpack loads on amputee gait patterns. This project examined the effects of a backpack load on the gait patterns of unilateral transtibial amputees. Ten participants performed walking trials on four surfaces (level ground, uneven ground, walking up an incline, and walking down an incline), without a pack and with a pack. A total of 40 trials were collected per subject, with 10 trials collected on each surface. Three-dimensional motion data were collected with an eight-camera Vicon Motion Analysis system to describe limb motion as well as compare kinematic outcomes between tasks and conditions. Force platform data were collected during the level ground trials and used to calculate kinetic measures for both limbs. With the addition of the pack changes were seen on each surface, with different changes occurring to each limb. The ramp up surface created the most changes when comparing the two conditions. The only change seen across all four surfaces was a decrease in ankle dorsiflexion before push-off on the prosthetic limb. The two next most common changes were increases in knee and hip flexion during weight-acceptance.

The aim of the study was to examine the muscle activities of fifteen male participants (23.44 ±2.63 years) during unilateral hockey bag load carrying of different weights (10%, 20%, and 30% bodyweight) and sizes (small and large). Walking without a hockey bag was the control condition. The results showed that increased peak and integrated EMG occurred with an increased load weight in the semitendinosus, gastrocnemius, rectus abdominis, and vastus medialis. The left rectus femoris and left semitendinosus were both significantly greater than the right corresponding muscle. Carrying the large hockey bag produced greater peak EMG in the right rectus abdominis and the right rectus femoris, whereas the right vastus medialis showed a larger peak EMG in the small hockey bag. It was concluded that the posterior-lateral carrying style of hockey bag load carriage explained the results being similar to both backpack and side pack load carriage studies.

It is currently unknown how lie detection accuracy is affected when someone is speaking in his or her second language. We examined whether language proficiency had an impact on lie detection. We hypothesized that when judging the veracity of second-language speakers, participants would be better able to discriminate between truth- and lie-tellers and would have bias toward picking ‘lying’ since they may display cues associated with lying when communicating.We collected video footage of native- and second-language English speakers who lied or told the truth about a transgression. Undergraduate students (N = 51) then judged the veracity of these clips and indicated how confident they were in their ratings. Participants were most accurate and confident when judging native-language truth-tellers. In addition, participants were more likely to exhibit a truth-bias when observing native-language speakers, whereas they were more likely to exhibit a lie-bias when viewing second-language speakers. Implications for the justice system will be discussed. / UOIT

Because of the highly complex structure of the load-sensing pump, its compensators and controlling elements, simulation of load-sensing pump system pose many challenges to researchers. One way to overcome some of the difficulties with creating complex computer model is the use of black box approach to create an approximation of the system behaviour by analyzing input/output relationships. That means the details of the physical phenomena are not so much of concern in the black box approach. Neural network can be used to implement the black box concept for system identification and it is proven that the neural network have the ability to model very complex behaviour and there is a well defined set of neural and neural network structures. Previous studies have shown the problems and limitations in dynamic system modeling using static neuron based neural networks. Some new neuron structures, Dynamic Neural Units (DNUs), have been developed which open a new area to the research associated with the system modelling.<p>The overall objective of this research was to investigate the feasibility of using a dynamic neural unit (DNU) based dynamic neural network (DNN) in modeling a hydraulic component (specifically a load-sensing pump), and the model could be used in a simulation with any other required component model to aid in hydraulic system design. To be truly representative of the component, the neural network model must be valid for both the steady state and the transient response. Due to three components (compensator, pump and control valve) in a load sensing pump system, there were three different pump model structures (the pump, compensator and valve model, the compensator and pump model, and the pump only model) from the practical point of view, and they were analysed thoroughly in this study. In this study, the DNU based DNN was used to model a pump only model which was a portion of a complete load sensing pump. After the trained DNN was tested with a wide variety of system inputs and due to the steady state error illustrated by the trained DNN, compensation equation approach and DNN and SNN combination approach were then adopted to overcome the steady state deviation. <p>It was verified, through this work, that the DNU based DNN can capture the dynamics of a nonlinear system, and the DNN and SNN combination can eliminate the steady state error which was generated by the trained DNN. <p>The first major contribution of this research was in investigating the feasibility of using the DNN to model a nonlinear system and eliminating the error accumulation problem encountered in the previous work. The second major contribution is exploring the combination of DNN and SNN to make the neural network model valid for both steady state and the transient response.

The primary function of a power system is to supply its customers with electrical energy as economically as possible and with acceptable reliability and quality. Generating capacity adequacy evaluation is the oldest and most extensively studied aspect of power system reliability assessment. A wide range of methods have been developed to perform this evaluation. Two computer programs were developed based on the analytical and simulation techniques and used as tools in this research work. A number of basic considerations in generating capacity adequacy evaluation are investigated. Generating unit residence time distributions and peaking load units are incorporated in the analysis.<p> Two commonly encountered misconceptions regarding the basic system reliability indices are examined by applying the two programs to two reliability test systems. Reliability index probability distributions can be used to supplement the information provided by the expected index values. The concept of creating distributions and the additional information that can be obtained is illustrated in this thesis. <p> Generating unit residence time distributions are generally categorized as being either exponential or non-exponential in form. The exponential distribution is utilized, however, in virtually all practical system studies. The impacts on the system reliability of non-exponential unit state residence time distributions are examined in this research. <p> Peaking load units and base load units have different operating characteristics. The functions of peaking load units vary with changes in the system operating conditions. This is examined in this research. <p>The conclusions and techniques presented in this thesis should prove valuable in power system planning and operation.

This dissertation presents the findings of a study to quantify the effect of heat source configurations on the performance of passive chilled beams. Experiments in a thermally controlled test room were conducted using thermal manikins as heat sources cooled with a 0.6 m by 2.4 m beam. The thermal manikins were arranged in a symmetric and an asymmetric configuration and tested over a range of input power to simulate a low-to-high load heat distribution of an indoor space. A computational fluid dynamics (CFD) model was developed in Star CCM+ v6.06 and used for further analysis of the flow field and to predict additional spatial arrangements of the beam, interior dimensions, and heat source configurations. The CFD model implemented a calculation for the beam cooling capacity to predict the beam performance based on the room thermal conditions. The experimental data revealed an average reduction of 15% in the passive beam cooling capacity for the asymmetrically configured thermal manikins compared to the symmetric arrangement. The CFD model was validated with the experimental data and predicted the asymmetric heat source beam performance reduction to be 17%. The reduction in performance based on the heat source arrangement was found with analysis of the CFD simulations to be a result of the above-beam air velocity field. The unbalanced thermal manikin configuration generated an unbalanced flow condition at the inlet of the beam that resulted in the room air circumventing the inlet of the passive beam, as compared to the inlet velocity field of the symmetric configuration. Additional configurations were investigated with the CFD model to include the beam position, floor area, ceiling height, and thermal manikin arrangements. The simulation results were analyzed by comparing the efficiency of beam performance using the beam cooling capacity calculation for each scenario. The predictions of additional configurations found that the efficiency increased when the beam was perpendicular to a group of heat sources and the changes in beam performance with heat source configurations was not affected by the interior dimensions of the space. However, the resulting thermal conditions in the occupied zone for the beam positions of highest efficiency may negatively impact the thermal comfort of occupants.