Sensitivity of Space Station alpha joint robust controller to structural modal parameter variations

The photovoltaic array sun tracking control system of Space Station Freedom is described. A synthesis procedure for determining optimized values of the design variables of the control system is developed using a constrained optimization technique. The synthesis is performed to provide a given level of stability margin, to achieve the most responsive tracking performance, and to meet other design requirements. Performance of the baseline design, which is synthesized using predicted structural characteristics, is discussed and the sensitivity of the stability margin is examined for variations of the frequencies, mode shapes and damping ratios of dominant structural modes. The design provides enough robustness to tolerate a sizeable error in the predicted modal parameters. A study was made of the sensitivity of performance indicators as the modal parameters of the dominant modes vary. The design variables are resynthesized for varying modal parameters in order to achieve the most responsive tracking performance while satisfying the design requirements. This procedure of reoptimization design parameters would be useful in improving the control system performance if accurate model data are provided

Power optimal single-axis articulating strategies

Power optimal single axis articulating PV array motion for Space Station Freedom is investigated. The motivation is to eliminate one of the articular joints to reduce Station costs. Optimal (maximum power) Beta tracking is addressed for local vertical local horizontal (LVLH) and non-LVLH attitudes. Effects of intra-array shadowing are also presented. Maximum power availability while Beta tracking is compared to full sun tracking and optimal alpha tracking. The results are quantified in orbital and yearly minimum, maximum, and average values of power availability

Citations of DESIDOC Journal of Library and Information Technology: Statistical Analysis of Google Scholar Based Research Impact for the Period of 2006 to 2015

Google Scholar (GS) is the only available global database for the citation analysis of Indian LIS journals. The present study is an attempt to highlight the citation output of research articles in DESIDOC Journal of Library and Information Technology (DJLIT) published during the period 2006–2015. This study is based on Google Scholar data. Descriptive and inferential statistical techniques were applied in the study. 406 articles were published during 2006–2015, which were cited 4122 times in Google Scholar. Based on Google Scholar, this study proves that the citation output of articles published in the DJLIT differs significantly with their publication year. The level of citation is not constant throughout the study period. There is also a weak negative correlation between citations of articles and its publication year. Although, GS covers wide spectrum of scholarly literature worldwide, this study found that DJLIT journal article’s visibility is decreasing in GS database

Authorship Pattern and Citation Level of i10 Cited Research Papers of DESIDOC Journal of Library and Information Technology in Google Scholar

Google Scholar (GS), a freely accessible database of scholarly papers along with its citations data, has an extensive coverage of Library and Information Science (LIS) literature. It is the only available global database for the citation analysis of Indian LIS journals. The present study is an attempt to highlight the authorship pattern and citation level of i10 cited research articles in DESIDOC Journal of Library and Information Technology (DJLIT) based on Google Scholar data. Descriptive and inferential statistical techniques were applied in the study. One hundred and eighty articles published between 1995–2016 were cited 10 or more times (i10 index) in Google Scholar. Based on Google Scholar, this study has established that citations of i10 cited papers are equally distributed in its different authorship patterns; there is no association between authorship pattern and level of citations. Further the study shows that there is an association between period of publication and level of citations

Accurate Determination of Comet and Asteroid Orbits Leading to Collision With Earth

Movements of the celestial bodies in our solar system inspired Isaac Newton to work out his profound laws of gravitation and motion; with one or two notable exceptions, all of those objects move as Newton said they would. But normally harmonious orbital motion is accompanied by the risk of collision, which can be cataclysmic. The Earth s moon is thought to have been produced by such an event, and we recently witnessed magnificent bombardments of Jupiter by several pieces of what was once Comet Shoemaker-Levy 9. Other comets or asteroids may have met the Earth with such violence that dinosaurs and other forms of life became extinct; it is this possibility that causes us to ask how the human species might avoid a similar catastrophe, and the answer requires a thorough understanding of orbital motion. The two red square flags with black square centers displayed are internationally recognized as a warning of an impending hurricane. Mariners and coastal residents who know the meaning of this symbol and the signs evident in the sky and ocean can act in advance to try to protect lives and property; someone who is unfamiliar with the warning signs or chooses to ignore them is in much greater jeopardy. Although collisions between Earth and large comets or asteroids occur much less frequently than landfall of a hurricane, it is imperative that we learn to identify the harbingers of such collisions by careful examination of an object s path. An accurate determination of the orbit of a comet or asteroid is necessary in order to know if, when, and where on the Earth s surface a collision will occur. Generally speaking, the longer the warning time, the better the chance of being able to plan and execute action to prevent a collision. The more accurate the determination of an orbit, the less likely such action will be wasted effort or, what is worse, an effort that increases rather than decreases the probability of a collision. Conditions necessary for a collision to occur are discussed, and warning times for long-period comets and near-Earth asteroids are presented

Protecting the Right to Health for Rare Disease Patients: Legal Frameworks, Policy Gaps, and the Need for Reform in India

Right to Health is a fundamental human right recognized by various international and regional treaties, and governments worldwide have a duty to ensure its protection. However, several impediments exist for the full realisation of this right which includes economic, social and political factors. This requires coordinated efforts from governments, international organisations and civil societies. Access to healthcare and medicines is central to this right. In the case of certain diseases, the full realisation of this is burdensome. This issue is reflected for individuals suffering from rare diseases, where orphan drugs, for their treatment are often unavailable due to the lack of incentives for pharmaceutical companies to invest in their development. Orphan diseases presents a complex dynamics due to the numerous diseases, varied and unidentifiable symptoms and difficulties in diagnosis. Orphan drugs face significant hurdles in research, development, and commercialization, primarily due to the small market size and high costs involved. These barriers leave patients without access to life-saving treatments, thereby increasing health inequities. Several countries have introduced incentives for orphan drug development, such as market exclusivity, tax credits, research grants, fee waivers, accelerated approval etc. However, accessibility remains restricted due to high costs and insufficient governmental support.India, with its large population suffering from rare diseases, lacks a robust regulatory framework to promote orphan drug development and ensure access for patients. Despite the introduction of the National Policy for Rare Diseases (NPRD) in 2021, there are significant gaps in incentivizing research and providing affordable treatment options. This paper examines the scope of right to health as a human right within both international and Indian contexts, analyzes the challenges associated with orphan drug development, and reviews the effectiveness of existing policies. It also explores global initiatives for development of orphan drugs, emphasizing the need for policy reform to ensure equitable healthcare for all

Quantitative assessment and Consequence modeling of deliberately induced Domino effects in Process facilities

PresentationProcess facilities handling hazardous chemicals at elevated temperature and pressure conditions are attractive targets to external attacks. The possibility of an external attack on a critical installation with an intention of triggering escalation of primary events into secondary and tertiary events, thereby increasing the severity of consequences needs to be effectively analyzed. A prominent Petrochemical Industry located in Kerala, India was identified for induced domino effect analysis. In this study, Bayesian network is used to model the development of a domino sequence and to quantitatively determine the occurrence probabilities of domino effect. Moreover, the updating feature of Bayesian networks is used to update probabilities in the light of new evidences. Phast Process hazard analysis software and ALOHA (Areal Locations of Hazardous Atmospheres) software is used for consequence modeling of the security event to obtain the impact zones. Recommendations to manage and reduce the domino effect attractiveness by incorporating inherently safer design concepts and use of appropriate active and passive mitigating barriers are also discussed

Comet/Asteroid Protection System (CAPS): Preliminary Space-Based Concept and Study Results

There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) is a future space-based system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This Technical Memorandum provides a compilation of key related topics and analyses performed during the CAPS study, which was performed under the Revolutionary Aerospace Systems Concepts (RASC) program, and discusses technologies that could enable the implementation of this future system

Citations of the Top 100 Most-cited Papers of the Journal Scientometrics in Web of Science and its Association and Correlation with Scopus and Google Scholar Citations

This study is conducted to analyse the citations of the top 100 most-cited papers of the journal Scientometrics in Web of Science (WoS) and its association and correlation with corresponding citations in Scopus and Google Scholar (GS). Chi-square and Spearman’s rank rho are used to ascertain the association and correlation among these citations in different platforms. GS citations for the papers are comparatively higher than the citations in the other two databases. Scopus citations are slightly higher than WoS citations. The study found that there is significant association among level of citations of top 100 cited papers of the journal Scientometrics in WoS and its corresponding level of citations in Scopus and Google Scholar and also high positive correlation among citations in the three databases

Citations of the Top 100 Most-cited Papers of the Journal Scientometrics in Web of Science and its Association and Correlation with Scopus and Google Scholar Citations

This study is conducted to analyse the citations of the top 100 most-cited papers of the journal Scientometrics in Web of Science (WoS) and its association and correlation with corresponding citations in Scopus and Google Scholar (GS). Chi-square and Spearman’s rank rho are used to ascertain the association and correlation among these citations in different platforms. GS citations for the papers are comparatively higher than the citations in the other two databases. Scopus citations are slightly higher than WoS citations. The study found that there is significant association among level of citations of top 100 cited papers of the journal Scientometrics in WoS and its corresponding level of citations in Scopus and Google Scholar and also high positive correlation among citations in the three databases