High precision motion control of parallel robots with imperfections and manufacturing tolerances

This work attempts to achieve precise motion control using parallel robots with manufacturing tolerances and inaccuracies by migrating the measurements from their joint space to task space in order to decrease control system’s sensitivity to any kinematical uncertainty rather than calibrating the parallel plant. The problem of dynamical model uncertainties and its effect on the derivation of the control law is also addressed in this work through disturbance estimation and compensation. Eventually, both task space measurement and disturbance estimation are combined to formulate a control framework that is unsensitive to either kinematical and dynamical system uncertainties

Sensorless torque estimation in multidegree-of-freedom flexible systems

This paper presents a sensorless torque estimation algorithm for multidegree-of-freedom flexible systems. The proposed algorithm makes it possible to estimate externally applied torques due to flexible system s interaction with the environment without taking any measurement from the system. The algorithm is based on modifying the disturbance observer in order to decouple the reflected torque waves out of the total disturbance on the actuator. Then Reflected torque waves are used along with the actuator s current and velocity to estimate flexible system parameters, dynamics and the external torques or disturbances. Several experimental results are included in order to confirm the validity of the proposed torque estimation algorithm

Nutritional value of Pleurotus (Flabellatus) Djamor (R-22) cultivated on sawdusts of different woods

The sawdust of different woods were investigat ed for the cultivation of exotic strain of Pleurotus (flabellatus) djamor (R-22) to find out the efficiency of different nutrients including protein, fat, crude fiber, ash, dry matter and moisture. Among all type of nutrients, protein, fat, cr ude fiber, ash, dry matter and moisture of Pleurotus ostreatus on sawdust of different woods were observed. Protein was observed on cont rol treatment (cotton waste, kikar, mango, mixed sawdust, simbal and kail (21.89), (21.64), (21.34), (21.16), (21.03) and (20.75) % respectively. Fat was observed on control treatment (cotton waste, kikar, mango, mi xed sawdust, simbal and kail (0.80), (0.53), (0 .41), (0.33), (0.24) and (0.11)% respectively. Crude fiber was observed on control treatment (cotton waste, kikar, mango, mixed sawdust, simbal and kail (8.92), (8.45), (8.17), (7.96), (7.70) and (7.32) % respectively. Ash was observ ed on control treatment (cotton waste, kikar, mango, mixed sawdust, simbal and kail (7.65), (6.75), (6 .47), (6.39), (6.33) and (6.23%) respectively. Dry matter was observed on control treatment (cotton waste, kikar, mango, mixed sawdust, simbal and kail (6.47), (6.27), (6.13), (6.01), (5.87) and (5.67) % respectively. Moisture was observed on control treatment (c otton waste, kikar, mango, mixed sawdust, simbal and kail (84.55), (81.20), (79.85), (76.26), (74.35) and (71.14) % respectively. Oyster mushroom showed relatively more contents on control treatment cotton waste as compared to other substrates. The maximum protein, fat, crude fiber, ash, dry matter and moisture contents in Pleurotus (flabellatus) djamor (R-22) was obtained on Kikar sawdust .The lowest contents was obtained on kail sawdust

Optimal motion control and vibration suppression of flexible systems with inaccessible outputs

This work addresses the optimal control problem of dynamical systems with inaccessible outputs. A case in which dynamical system outputs cannot be measured or inaccessible. This contradicts with the nature of the optimal controllers which can be considered without any loss of generality as state feedback control laws for systems with linear dynamics. Therefore, this work attempts to estimate dynamical system states through a novel state observer that does not require injecting the dynamical system outputs onto the observer structure during its design. A linear quadratic optimal control law is then realized based on the estimated states which allows controlling motion along with active vibration suppression of this class of dynamical systems with inaccessible outputs. Validity of the proposed control framework is evaluated experimentally

Dichromacy: Color Vision Impairment and Consanguinity in Heterogenous Population of Pakistan

Background and Objectives: Dichromacy, an X-linked recessive disorder is identified worldwide, more in males than females. In European Caucasians, its incidence is 8% in males and 0.5% in females. In India, it is 8.73% in males and 1.69% in females, and in Iran, it is 8.18% in males and 0.43% in females. Population based epidemiological data about dichromacy in different ethnic groups in Pakistan is not available. The aim of this study was to find out the population prevalence of inherited red-green dichromacy in a heterogenous population of the district of Chiniot, Punjab, Pakistan, and to determine the impact of consanguinity and ethnicity. Methods: In this cross-sectional study, boys and girls of the higher secondary schools were examined in the three tehsils of district Chiniot. Pseudoisochromatic Ishihara Test has been employed for detection of dichromacy in the study population. The sample size was calculated statistically as 260, which was expanded to 705 and divided by population density of the three tehsils. Results: Screening of 359 males and 346 females revealed 19 (5.29%) dichromat males and only 2 (0.58%) females. The study population belonged to 23 castes / isonym groups. The consanguinity found in the district of Chiniot is 84.82% and in the dichromat families, it is 85.71%, of which 52.37% are first cousin. Interpretation & Conclusion: The study has shown that the incidence of dichromacy could be reduced through genetic counselin

Road crossing behaviors of pedestrians in two different virtual reality environments

About 20% of all people killed on roads are pedestrians. Virtual Reality (VR) simulators can be used to train street crossing and improve pedestrian safety, but the use of this technology has some limitations that need to be addressed. Common issues are related to the ecological validity of the experience because of poor immersion, movement limitations, and lack of visual and audio effects. In addition, these simulators are often very expensive. To address this, we developed a pedestrian street-crossing simulation that can be delivered through two mediums, a low-cost CAVE (Cave Automatic Virtual Environment) or a Head-Mounted Display (HMD). These two environments provide a high immersive experience, simple architecture, and a lower cost of deployment. Following an independent samples design, 20 participants were randomly allocated to the CAVE or HMD group and performed a street-crossing task. We measured the percentage of collisions with vehicles and presence through the Witmer and Singer Presence Questionnaire. Our results show that the percentage of collisions was significantly higher in the HMD group. Presence scores were high for both groups, but not significantly different. These results can be used to inform the design of VR simulators for safe street-crossing.info:eu-repo/semantics/publishedVersio

On The Application Of Log Compression and Enhanced Denoising In Contrast Enhancement Of Digital Radiography Images

Digital radiography (DR) is becoming popular for the point of care imaging in the recent past. To reduce the radiation exposure, controlled radiation based on as low as reasonably achievable (ALARA) principle is employed and this results in low contrast images. To address this issue, post-processing algorithms such as the Multiscale Image Contrast Amplification (MUSICA) algorithm can be used to enhance the contrast of DR images even with a low radiation dose. In this study, a modification of the MUSICA algorithm is investigated to determine the potential for further contrast improvement specifically for DR images. The conclusion is that combining log compression and its inverse at the appropriate stage with a multi-stage MUSICA and denoising is very promising. The proposed method resulted in an average of 66.5 % increase in the mean contrast-to-noise ratio (CNR) for the test images considered.Comment: 4 pages, 4 figure

Risk Factors of Diarrhoea in Malnourished Children Under Age of 5 Years

Background: Acute infectious enteritis remains one of the commonest causes of death among infants and children in developing countries. Acute enteritis is defined as a loss of stool consistency with pasty or liquid stools, and/or an increase in stool frequency to more than three stools in 24 hours with or without fever or vomiting. Human survival depends on the secretion and reabsorption of fluid and electrolytes in the intestinal tract. The objective of the study is to evaluate the risk factors of diarrhoea in children under age of 5 years. Methodology: It was an observational study. Study was completed in about six months. Non-probability purposive sampling technique was used. In this study, 270 samples were taken from Diarrheal ward of The Children Hospital Lahore, Pakistan. Results: In this study, out of 270 patients, 58.52% were males and 41.48% were females. 90.37% patients were vaccinated. 54.81% had weaning history. 91.85% patients had feeding history. 29.26% had blood in stool. 96.67% patients were dehydrated. 95.56% patients had loose watery diarrhoea. 62.96% patients used boiled water. 58.52% patients consumed less than half litre of water, 30.00% patients consumed 1 litre of water and 11.48% patients consumed > 1 litre of water. 49.18% patients had proper hygiene. 38.15% mothers of patients were well educated. 40.37% patients had model household condition. 57.41% patients lived in rural area and 42.59% patients lived in urban area. Conclusion: The variation in the level of diarrheal morbidity was well explained by maternal education, income, personal hygiene, refuse disposal system and the effect of health extension programme