scholarly journals Optimization of Complex Function Variable

Author(s):  
Kamlesh Kumar Naik
1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.


Author(s):  
William J. Dougherty

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.


2020 ◽  
Author(s):  
C Koppe ◽  
F Reisinger ◽  
K Wehr ◽  
M Vucur ◽  
C Trautwein ◽  
...  

Author(s):  
Anfal Muayad Mayoof

Hospitals are the major contributor to environmental corruption and the biggest drain onenergy in their life cycle because they are complex, multifunctional giant facilities. Several recent studieshave been carried out to find the most suitable solutions to reduce energy consumption provide it on-siteand contribute to supporting economic, environmental and social aspects. The reason for the slowmovement of green buildings for hospitals is to focus on a suitable design for the complex function thatdeals with the local climate, natural resources, economy and cultural values and avoid the one-size-fits alldesign. This made the solutions used multiple and varied, different for greening of the hospital and put theresearch in the absence of a clear perception of the mechanisms of the application of green architecture inhospitals and this identified the problem of research. Therefore, the study looked at an analytical study ofexisting project models designed according to the strategies and standards of green architecture todetermine the strategies adopted in each project, and by adopting the analytical method after determiningthe strategy used in each building to achieve the green architecture and then comparing them according tothe standards adopted using the global LEED system Green Building Council. The results that will bereached are the mechanisms of applying Green Architecture to Hospitals.


Author(s):  
Mihály Bakonyi ◽  
Hugo J. Woerdeman

Intensive research in matrix completions, moments, and sums of Hermitian squares has yielded a multitude of results in recent decades. This book provides a comprehensive account of this quickly developing area of mathematics and applications and gives complete proofs of many recently solved problems. With MATLAB codes and more than two hundred exercises, the book is ideal for a special topics course for graduate or advanced undergraduate students in mathematics or engineering, and will also be a valuable resource for researchers. Often driven by questions from signal processing, control theory, and quantum information, the subject of this book has inspired mathematicians from many subdisciplines, including linear algebra, operator theory, measure theory, and complex function theory. In turn, the applications are being pursued by researchers in areas such as electrical engineering, computer science, and physics. The book is self-contained, has many examples, and for the most part requires only a basic background in undergraduate mathematics, primarily linear algebra and some complex analysis. The book also includes an extensive discussion of the literature, with close to six hundred references from books and journals from a wide variety of disciplines.


2015 ◽  
Vol 3 (1) ◽  
pp. 93
Author(s):  
Nik Maheran Nik Muhammad

This article advocates that research is lacking on the connection between leadership theory and social network theory. To date, little empirical research has been conducted on leadership and social networks. Thus, the proposition of this article goes beyond traditional leadership models to advocate for a fuller and more integrative focus that is multilevel, multi-component and interdisciplinary, while recognizing that leadership is a complex function of both the organisational leaders and the followers who perform tasks, all of which subsequently leads to decision making qualities. Indeed, the current leadership model focuses on leadership behaviour and the ability to gain followers mutuality, to achieve decision making quality involving the integration of leadership and social network theories. Given the apparent mutable palette of contemporary leadership theory, this emergent construct of the leadership paradigm can expand the poles of the leadership continuum and contribute to a richer and deeper understanding of the relationships and responsibilities of leaders and followers as they relate to decision making qualities. This new construct, which is termed prophetic leadership, explores the literature of the life experiences of the prophet in the ‘Abrahamic Faith’ religion. Drawing on a priori links between the personality trait and spiritual leadership that has recently garnered the interest of scholars, the present study asserts a normative leadership theory that links the personal quality of a leader, posture and principal (based on the Prophet’s leadership behaviour) to synergy and decision making quality. Altruism is proposed to enhance relationships between leadership behaviour and decision making quality. For future research, much work needs to be done specifically aiming to (a) achieve greater clarity of construct definitions, (b) address measurement issues, and (c) avoid construct redundancy.


2015 ◽  
Vol 1 (3) ◽  
pp. 93
Author(s):  
Nik Maheran Nik Muhammad

This article advocates that research is lacking on the connection between leadership theory and social network theory. To date, little empirical research has been conducted on leadership and social networks. Thus, the proposition of this article goes beyond traditional leadership models to advocate for a fuller and more integrative focus that is multilevel, multi-component and interdisciplinary, while recognizing that leadership is a complex function of both the organisational leaders and the followers who perform tasks, all of which subsequently leads to decision making qualities. Indeed, the current leadership model focuses on leadership behaviour and the ability to gain followers mutuality, to achieve decision making quality involving the integration of leadership and social network theories. Given the apparent mutable palette of contemporary leadership theory, this emergent construct of the leadership paradigm can expand the poles of the leadership continuum and contribute to a richer and deeper understanding of the relationships and responsibilities of leaders and followers as they relate to decision making qualities. This new construct, which is termed prophetic leadership, explores the literature of the life experiences of the prophet in the ‘Abrahamic Faith’ religion. Drawing on a priori links between the personality trait and spiritual leadership that has recently garnered the interest of scholars, the present study asserts a normative leadership theory that links the personal quality of a leader, posture and principal (based on the Prophet’s leadership behaviour) to synergy and decision making quality. Altruism is proposed to enhance relationships between leadership behaviour and decision making quality. For future research, much work needs to be done specifically aiming to (a) achieve greater clarity of construct definitions, (b) address measurement issues, and (c) avoid construct redundancy.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1488
Author(s):  
Damian Trofimowicz ◽  
Tomasz P. Stefański

In this paper, novel methods for the evaluation of digital-filter stability are investigated. The methods are based on phase analysis of a complex function in the characteristic equation of a digital filter. It allows for evaluating stability when a characteristic equation is not based on a polynomial. The operation of these methods relies on sampling the unit circle on the complex plane and extracting the phase quadrant of a function value for each sample. By calculating function-phase quadrants, regions in the immediate vicinity of unstable roots (i.e., zeros), called candidate regions, are determined. In these regions, both real and imaginary parts of complex-function values change signs. Then, the candidate regions are explored. When the sizes of the candidate regions are reduced below an assumed accuracy, then filter instability is verified with the use of discrete Cauchy’s argument principle. Three different algorithms of the unit-circle sampling are benchmarked, i.e., global complex roots and poles finding (GRPF) algorithm, multimodal genetic algorithm with phase analysis (MGA-WPA), and multimodal particle swarm optimization with phase analysis (MPSO-WPA). The algorithms are compared in four benchmarks for integer- and fractional-order digital filters and systems. Each algorithm demonstrates slightly different properties. GRPF is very fast and efficient; however, it requires an initial number of nodes large enough to detect all the roots. MPSO-WPA prevents missing roots due to the usage of stochastic space exploration by subsequent swarms. MGA-WPA converges very effectively by generating a small number of individuals and by limiting the final population size. The conducted research leads to the conclusion that stochastic methods such as MGA-WPA and MPSO-WPA are more likely to detect system instability, especially when they are run multiple times. If the computing time is not vitally important for a user, MPSO-WPA is the right choice, because it significantly prevents missing roots.


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