Dynamicsoaringisaversatilemaneuverexecutedtoacquireenergyavailable in the atmospheric wind shears. For UAVs, dynamic soaring maneuvers have mostly been confined in literature to fixed configurations. In order to analyzetheextenttowhichdynamicsoaringisinfluencedbydifferentmorphologies, aninnovativeconceptofintegratingdynamicsoaringwithmorphingcapabilities is introduced in this research. Through simulations, two major studies were performed. One of them analyzed the impact of span morphology and the other of sweep morphology on dynamic soaring parameters. An Unmanned Air Vehicle(UAV) with standard wing-tail configuration is considered. The aerodynamic modeling is based on empirical estimation procedure duly validate dwit numerical Vortex Lattice Method(VLM).Three-dimensional point-mass UAV equations of motion and nonlinear wind gradient profile are used to model the flight dynamics. The trajectory optimization problem is formulated as an optimal control problem using hp-adaptive Guassian quadrature collocation technique. Optimal soaring trajectories are generated for both morphologies. Parametriccharacterizationofthekeyperformanceparametersisperformed to determine the optimal platform configuration during various phases of the maneuver. The comparison of morphing ability during flight is compared with its fixed-wing counterpart. Simulation results demonstrate the benefits of extending soaring maneu vers to morphing configurations and its viability for onboard utilization. Results indicate 15% lesser required wind shear by the proposed span morphology and 14% lesser required wind shear by the proposed sweep morphology, in comparison to their respective fixed wing counterparts. This shows that the morphing UAVcanperformdynamicsoaringinanenvironment,wherefixedconfiguration UAVs might not, because of lesser available wind shears. Apart from this, span morphology reduced drag by 15%, lift requirement by 11% and angle of attack requirement by 20%, whereas increased the maximum velocity by 6.2%, normalized energies by 9% and improved loitering parameters (approximately 10%), in comparison to fixed span configurations. Similarly, sweep morphology guaranteed 20% drag reduction, 16% lesser angle of attack requirement and improved loitering performance over the fixed sweep configurations. The stability analysis of the nonlinear system along the optimal trajectory is then performed utilizing both linear (Floquettheory) and nonlinear (Contraction theory) techniques. Stability of dynamic soaring orbits is important since the trajectories can get disturbed by a strong gust or crosswinds causing the UAV to veer off-course. Although control system can be designed, a stable orbit can reduce the control effort and power. The problem of analyzing stability is treated from the context of a periodic coefficient system. The stability analysis revealed that a closed-loop control is necessary as the system dynamics are inherently unstable. AgeometricnonlinearcontrollabilityanalysisofUAVunderdynamicsoaring conditions is then performed. To achieve such an objective, the state-of-theartmathematicaltoolsofnonlinearcontrollabilityareutilized. Thecontrollability of a flying vehicle along that optimal soaring trajectory is analyzed. More im portantly, the geometric nonlinear controllability characteristics of generic flight dynamics is analyzed in the presence and absence of wind shear to provide a controllability explanation for the role of wind shear in the physics of dynamic soaring flight. It is found that the wind shear is instrumental in ensuring controllability as it allows the UAV attitude controls (pitch and roll) to play the role of thrust in controlling the flight path angle. The presented analysis represents a controllability-based mathematical proof for the energetics of flight physics.
" کتنی ہی امتوں کو ہم (عذاب سے) ہلاک کر چکے ہیں سو انہوں نے (ہلاکت کے وقت) بڑی ہائے پکار کی اور وہ وقت خلاصی کا نہ تھا"۔
یعنی ان کو معلوم رہنا چاہیے کہ اسی غرور وتکبر کی بدولت انبیاء اللہ سے مقابلہ ٹھان کر بہت سی جماعتیں پہلے تباہ و برباد ہو چکی ہیں وہ لوگ بھی مدتوں پیغمبروں سے لڑتے رہے۔ پھر جب برا وقت آ پڑا اور عذاب الٰہی نے چاروں طرف سے گھیر لیا تو گھبرا کر شور مچانے اور خدا کو پکارنے لگے۔ مگر اس وقت فریاد کرنے سے کیا بنتا۔ خلاصی کا موقع گزر چکا تھا، اور وقت نہیں رہا تھا کہ ان کے شوروبکاء کی طرف توجہ کی جائے۔
In Pakistan, although women’s activism was initiated since the country came into existence, but a diverse activism was observed by the nation in the form of ‘Aurat March during 2018-2020. The current study examines the Western feminism, what it was initiated for and its accomplishments in the current time. By employing a discourse analysis approach to the ‘Aurat March event, this study highlights the women’s activism in Pakistan, ‘Aurat March and the antipathy faced by organizers and supporters from the public because of its strange slogans and ridiculous placards. It also observes the relationship between western feminism and ‘Aurat March activism from the perspective of the social, cultural, and religious transformation of society. The study finds the need to raise a constructive and logical voice for women’s rights with support of the public to eradicate social evils instead of focusing on insignificant matters. It has further recommended that there is a need to build a framework in which one may be able to differentiate women’s rights in the context of western feminism and the limitation of women’s emancipation in Islamic context.
This research was an attempt to find out the current practice of teachers' performance appraisal of a community-based school and its implications for management's role in implementing the appraised processes effectively. Appraisal is generally used for both accountability and professional development. This mostly depends on the school's objectives for carrying out the appraisal. It is noted that teachers get uncomfortable and feel threatened by the performance appraisal process. This could be for two main reasons: (a) when the objectives of appraisal exercises are not made clear to the teachers, they do not know what this would lead to; (b) teachers become threatened if they know that, the school will use the findings to decide about teachers annual increments and promotions. Literature, however, suggests that performance appraisal should be for teachers' professional development. The exercise should be a road map for teachers and finding should help teachers to grow professionally. I carried out an exploratory case study to find out the current practices of carrying out teachers' performance appraisal of a particular school; their perceptions about the teachers' performance appraisal and to know whether the findings of teachers' performance appraisal enabled the teachers to grow professionally. The findings of the study revealed that, the teachers associated the performance appraisal not with professional growth but with the amount of increment in salary, dismissal in case of poor performance and promotion or demotion. However, there are different perceptions about the utility of appraisal among the stakeholders. Some relate this to professional development, others categorize the teachers in A' and B' category and based on this categorizes give increments. It was evident that the purpose of the practice is not clear to teachers. Appraisers do not negotiate and inform the details on which teachers are appraised. There are no pre and post appraisal meetings to discuss teachers' progress and future needs. Also there is lack of clarity about the purpose and objectives of being appraisal In view of the findings and considering the importance of the performance appraisal exercise, this dissertation recommends that objectives of teachers' performance appraisal be shared with teachers; the system should be more transparent and proper procedure of appraisal should be followed to gain maximum benefit from it and give qualitative feedback to the teachers.