Simulation and control problems in elastic robots

Computational issues associated with modeling and control of robots with revolute joints and elastic arms are considered. A manipulator with one arm and pinned at one end is considered to investigate various aspects of the modeling procedure and the model, and the effect of coupling between the rigid-body and the elastic motions. The rigid-body motion of a manipulator arm is described by means of a reference frame attached to the shadow beam, and the linear elastic operator denoting flexibility is defined with respect to this reference frame. The small elastic motion assumption coupled with the method of assumed modes is used to model the elasticity in the arm. It is shown that only terms up to quadratic in these model amplitudes need to be retained. An important aspect of the coupling between the rigid-body and the elastic motion is the centrifugal stiffening effect. This effect stiffens the elastic structure, as to be expected on physical grounds, gives rise to a time-varying inertia term for the rigid-body motion, and, in general, results in an effective inertia term smaller than the rigid-body inertia term. Simulation results are presented for an elastic beam pinned at one end and free at the other, and rotating in a horizontal plane, and control issues such as the order of the model, number of sensors, and modal extraction are examined within this context

Adaptive Bit Allocation With Reduced Feedback for Wireless Multicarrier Transceivers

With the increasing demand in the wireless mobile applications came a growing need to transmit information quickly and accurately, while consuming more and more bandwidth. To address this need, communication engineers started employing multicarrier modulation in their designs, which is suitable for high data rate transmission. Multicarrier modulation reduces the system's susceptibility to the frequency-selective fading channel, by transforming it into a collection of approximately flat subchannels. As a result, this makes it easier to compensate for the distortion introduced by the channel. This thesis concentrates on techniques for saving bandwidth usage when employing adaptive multicarrier modulation, where subcarrier parameters (bit and energy allocations) are modulated based on the channel state information feedback obtained from previous burst. Although bit and energy allocations can substantially increase error robustness and throughput of the system, the feedback information required at both ends of the transceiver can be large. The objective of this work is to compare different feedback compression techniques that could reduce the amount of feedback information required to perform adaptive bit and energy allocation in multicarrier transceivers. This thesis employs an approach for reducing the number of feedback transmissions by exploiting the time-correlation properties of a wireless channel and placing a threshold check on bit error rate (BER) values. Using quantization and source coding techniques, such as Huffman coding, Run length encoding and LZWalgorithms, the amount of feedback information has been compressed. These calculations have been done for different quantization levels to understand the relationship between quantization levels and system performance. These techniques have been applied to both OFDM and MIMO-OFDM systems

Perception of Indian Dental Students to Pursue Higher Education Abroad during COVID-19

Objective: To evaluate Indian dental students’ perception of seeking international dental higher education during COVID-19. Material and Methods: We conducted an online survey among the dental students. A self-administered questionnaire was prepared, which had information on country choice, reasons for the decision to study abroad, measures to be taken by the foreign universities because of COVID-19, the application’s status, current plan, and opinions on exploring other possibilities. Results: Four hundred students constituted the final sample, out of which the majority were females (69.3%). Most of the students were not sure about their status in the application process (63%). The current plan to study abroad remained uncertain for almost half of the students (50.2%). Concerning the status of the application process, a significantly higher number of female students were “not sure” and are still “searching colleges” (p<0.001). Similarly, a higher number of females were “uncertain” or “postponed” or “canceled” when compared to the males concerning the current plan to study abroad (p=0.001). Also, a significantly higher proportion of female students cited the study budget as the main deterrent for pursuing a career abroad and opined that “flexible study options” will help them get admissions post-COVID-19 (p=0.001 and 0.035). Conclusion: A substantial impact was perceived by Indian dental students concerning higher education abroad, more among females

ATC Enhancement With FACTS Devices Considering Reactive Power Flows Using PTDF

In the present day world power system deregulation is at its full stretch. In this deregulated environment there is a clear need for adequate computation of ATC which is currently being given at most importance. The insertion of FACTS devices in electrical systems seems to be a promising strategy to enhance ATC. In this paper, the viability and technical merits of boosting ATC using TCSC are analyzed. The methods used for determining ATC are linear methods, which are based on MVA loading of the system considering system thermal limit constraints, neglecting bus voltages and static collapse. Power Transfer Distribution Factors, commonly referred to as PTDFs, express the percentage of a power transfer that flows on a transmission facility. They are used to determine the maximum ATC that may be available across the system without violating line thermal limits. The effect of reactive power flows in line loading is not considered in linear ATC which is a major limitation. This paper describes a fast algorithm to incorporate this effect. In this paper the line post transfer complex flow is estimated based on exact circle equation and then ATC is evaluated using active power distribution factors. The effectiveness of the proposed method is successfully demonstrated on IEEE 30-Bus system.DOI:http://dx.doi.org/10.11591/ijece.v3i6.392

A splenic hydatid cyst in young female: a case report

Splenic hydatid disease is a rare kind of hydatid disease, accounting for less than 8% of cases in humans. Here we present a case of 23 years old female patient came to hospital with chief complaints of pain radiating to left quadrant in the last 2 years and cough with sputum and nausea and admitted in the hospital for further evaluation. CT chest shows cystic mass in the left hypochondrium lateral to the stomach compressing the stomach, later did CT abdomen which clearly indicates the spleen is enlarged in size with well-defined hypodense non enhancing unilocular cystic lesion measuring 13×13×11 cm (CC×AP×TR) in the upper and mid poles

Anti-plaque and anti-gingivitis effect of Papain, Bromelain, Miswak and Neem containing dentifrice : a randomized controlled trial

Patients undergoing fixed orthodontic therapy may have difficulty in maintaining a good oral hygiene due to the difficulty posed by the appliances in accessing such areas. This study aimed to compare anti-plaque and anti-gingivitis efficacy of dentifrice containing Papain, Bromelain, Miswak and Neem with a standard dentifrice among patient?s undergoing fixed orthodontic treatment. Single center, single blind, parallel arm, randomized controlled clinical trial with an allocation ratio of 1:1 was conducted. Evaluation of plaque and gingivitis was done using Williams modification of Silness and Loe Plaque Index (PI) for use in orthodontic subjects and Loe and Silness?s Gingival Index (GI) at baseline and one month. Inter-group comparison showed there was significantly lower mean plaque index in test (0.88 ±0.05) than in control group (1.17 ±0.05) after adjusting for the baseline plaque index (p<0.001). Similarly, there was significantly lower mean gingival index in test (0.87 ±0.04) than in control group (1.14 ±0.04) after adjusting for the baseline gingival index (p<0.001). The efficacy of the test dentifrice in limiting plaque and gingivitis suggests that it can be used as a home based adjunct to clinical therapy in orthodontic patients

Essays On Intellectual Property Litigation

The last couple of decades have witnessed an increase in the number of patent litigations, especially in industries in which patents are a key source of competitive advantage. In my dissertation I examine how patent litigation between firms can influence outcomes at the firm level and at the individual level. In my first essay, I propose that patent litigation conveys negative information about start-ups to incumbent firms. Additionally, I propose that it also undermines the value of signals such as venture capital and alliance network prominence on the formation of alliances in the future. We suggest that these signals aid in the broadcast of the negative information which adversely impacts their prospects of forming alliances. In my second essay, we examine the impact of patent litigation on inventors. Specifically, we propose that such litigation impacts inventor&rsquo;s mobility between firms, in addition to the collaborative relationships they form with inventors within the organization. We suggest that patent litigation, increases the costs associated with their reputation and costs associated with hiring. Additionally, due to an increase in search costs to find collaborators, an increase in costs of collaboration due to reputational concerns of the sued inventors, and the opportunity cost they have to endure to fight litigation, inventors can find it challenging to form relationships that help promote innovation within the firm. Finally, in my third essay, I compare the inclusion of exclusivity provisions in volitional licensing agreements and those that are signed as a result of settlement of patent litigation between parties. Specifically, we suggest that licensing agreements signed post settlement are less likely to include exclusivity provisions due to an increase in the transactional hazards between the parties. Evidence from our data suggest that while exclusivity is used as a contractual safeguard to protect licensee investments in complementary assets especially when there is uncertainty in the technology, this relationship is adversely impacted in the deals signed post settlement. Finally, we also examine the inclusion of exclusivity provisions in settlement contracts signed between parties that relied on relational governance mechanisms such as past licensing relationships. We suggest that it is hard to rebuild the trust that parties once had over repeated interactions with each other, which adversely impacts their choice to grant a partner exclusive access to technologies.</p

Formulation and Evaluation of Emtricitabine and Tenofovir- Disoproxil Fumarate Immediate Release Film Coating Tablets.

The present work is to formulate film coated tablets of Emtricitabine combination with Tenofovir disoproxil fumaratetablets comparable to the marketed product.present work is to formulate film coated tablets of Emtricitabine combination with Tenofovir disoproxil fumaratetablets comparable to the marketed product. To study the release profile of the dosage form and to compare their drug-release profiles with the innovator. To determine the best fit dissolution profile for dosage form. To study the stability of dosage form and compare with the specification.The physical parameters evaluation, in-vitrodrug release studies and stability studies are conducted to justify the formulation efficacy. The immediate release tablets of Emtricitabine combination with Tenofovir disoproxil fumarate have been developed with wet granulation method with serial increasing Disintegrant concentration ratio in each subsequent batch. And it is compared with that of Marketed(Truvada) tablets. Various trials were performed to get the optimized formula with Disintigrent HPCLH-11. Among all the design formulations F8 is showing optimized (acceptable) results within USP limits. There is no undesirable change is found in accelerated stability condition for 1&3 months in optimized formulated batch. From the above all Formulations and observations we conclude that batch no F8 is showing result with in USP limits and same like Innovator. So further in vivo studies can be performe

Wheezy adult with chicken bone in the chest

A large foreign body aspiration in a healthy adult is rare in the literature. It is a frequent problem in children and adolescents. Adults are affected in altered sensorium, either due to sedation or neurological problems. Acute upper airway obstruction though rare in adults requires establishment of an airway using Laryngoscope or rigid bronchoscope. At times we have to recourse to tracheostomy to save the life. Foreign body often travels down the right sided airways, here we present a case of 30mm Chicken bone being lodged in the left main bronchus. The patient presented with unremitting cough and normal chest skiagram. Monophonic wheeze on auscultation and focused attention on the patient narration made us clinch the diagnosis. New onset wheezy chest or unremitting chronic airway disease on adequate therapy, with history of choking needs special attention. The CT scan is a better modality of the investigation. Three dimensional CT with multi-slice virtual bronchoscopy is advantageous. We discussed foreign body aspirations in adults, the various causes and presentations. Fiber optic bronchoscopy is the ideal method for visualization and extraction of non-life-threatening foreign bodies in adults. Once a foreign body is identified, it has to be removed as early as possible. Retained foreign bodies can precipitate many complications related to infection and inflammation. At rare incidence we may have to resort to thoracotomy to remove a complicated foreign body