scholarly journals Towards algorithm-free physical equilibrium model of computing

2021 ◽  
Vol 21 (15&16) ◽  
pp. 1296-1306
Author(s):  
Seyed Mousavi

Our computers today, from sophisticated servers to small smartphones, operate based on the same computing model, which requires running a sequence of discrete instructions, specified as an algorithm. This sequential computing paradigm has not yet led to a fast algorithm for an NP-complete problem despite numerous attempts over the past half a century. Unfortunately, even after the introduction of quantum mechanics to the world of computing, we still followed a similar sequential paradigm, which has not yet helped us obtain such an algorithm either. Here a completely different model of computing is proposed to replace the sequential paradigm of algorithms with inherent parallelism of physical processes. Using the proposed model, instead of writing algorithms to solve NP-complete problems, we construct physical systems whose equilibrium states correspond to the desired solutions and let them evolve to search for the solutions. The main requirements of the model are identified and quantum circuits are proposed for its potential implementation.

Author(s):  
Chun Lu ◽  
Xingyi Zhang

Tissue P systems is a computing model in the framework of membrane computing inspired from intercellular communication and cooperation between neurons. Many different variants of this model have been proposed. One of the most important models is known as tissue P systems with cell separation. This model has the ability of generating an exponential amount of workspace in linear time, thus it allows us to design cellular solutions to NP-complete problems in polynomial time. In this paper, we present a solution to the Vertex Cover problem via a family of such devices. This is the first solution to this problem in the framework of tissue P systems with cell separation.


Author(s):  
Robert L. Fry

This paper proposes that intelligent processes can be completely explained by thermodynamic principles. They can equally be described by information-theoretic principles that, from the standpoint of the required optimizations, are functionally equivalent. The underlying theory arises from two axioms regarding distinguishability and causality. Their consequence is a theory of computation that applies to the only two kinds of physical processes possible—those that reconstruct the past and those that control the future. Dissipative physical processes fall into the first class, whereas intelligent ones comprise the second. The first kind of process is exothermic and the latter is endothermic. Similarly, the first process dumps entropy and energy to its environment, whereas the second reduces entropy while requiring energy to operate. It is shown that high intelligence efficiency and high energy efficiency are synonymous. The theory suggests the usefulness of developing a new computing paradigm called Thermodynamic Computing to engineer intelligent processes. The described engineering formalism for the design of thermodynamic computers is a hybrid combination of information theory and thermodynamics. Elements of the engineering formalism are introduced in the reverse-engineer of a cortical neuron. The cortical neuron provides perhaps the simplest and most insightful example of a thermodynamic computer possible. It can be seen as a basic building block for constructing more intelligent thermodynamic circuits.


2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiao Yuan ◽  
Syed M Assad ◽  
Jayne Thompson ◽  
Jing Yan Haw ◽  
Vlatko Vedral ◽  
...  

AbstractIn general relativity, closed timelike curves can break causality with remarkable and unsettling consequences. At the classical level, they induce causal paradoxes disturbing enough to motivate conjectures that explicitly prevent their existence. At the quantum level such problems can be resolved through the Deutschian formalism, however this induces radical benefits—from cloning unknown quantum states to solving problems intractable to quantum computers. Instinctively, one expects these benefits to vanish if causality is respected. Here we show that in harnessing entanglement, we can efficiently solve NP-complete problems and clone arbitrary quantum states—even when all time-travelling systems are completely isolated from the past. Thus, the many defining benefits of Deutschian closed timelike curves can still be harnessed, even when causality is preserved. Our results unveil a subtle interplay between entanglement and general relativity, and significantly improve the potential of probing the radical effects that may exist at the interface between relativity and quantum theory.


2013 ◽  
Vol 10 (2) ◽  
pp. 115-124
Author(s):  
Philip L. Martin

Japan and the United States, the world’s largest economies for most of the past half century, have very different immigration policies. Japan is the G7 economy most closed to immigrants, while the United States is the large economy most open to immigrants. Both Japan and the United States are debating how immigrants are and can con-tribute to the competitiveness of their economies in the 21st centuries. The papers in this special issue review the employment of and impacts of immigrants in some of the key sectors of the Japanese and US economies, including agriculture, health care, science and engineering, and construction and manufacturing. For example, in Japanese agriculture migrant trainees are a fixed cost to farmers during the three years they are in Japan, while US farmers who hire mostly unauthorized migrants hire and lay off workers as needed, making labour a variable cost.


2020 ◽  
Vol 50 (1-2) ◽  
pp. 58-66
Author(s):  
Giuliano Pancaldi

Here I survey a sample of the essays and reviews on the sciences of the long eighteenth century published in this journal since it was founded in 1969. The connecting thread is some historiographic reflections on the role that disciplines—in both the sciences we study and the fields we practice—have played in the development of the history of science over the past half century. I argue that, as far as disciplines are concerned, we now find ourselves a bit closer to a situation described in our studies of the long eighteenth century than we were fifty years ago. This should both favor our understanding of that period and, hopefully, make the historical studies that explore it more relevant to present-day developments and science policy. This essay is part of a special issue entitled “Looking Backward, Looking Forward: HSNS at 50,” edited by Erika Lorraine Milam.


1997 ◽  
Vol 36 (4I) ◽  
pp. 321-331
Author(s):  
Sarfraz Khan Qureshi

It is an honour for me as President of the Pakistan Society of Development Economists to welcome you to the 13th Annual General Meeting and Conference of the Society. I consider it a great privilege to do so as this Meeting coincides with the Golden Jubilee celebrations of the state of Pakistan, a state which emerged on the map of the postwar world as a result of the Muslim freedom movement in the Indian Subcontinent. Fifty years to the date, we have been jubilant about it, and both as citizens of Pakistan and professionals in the social sciences we have also been thoughtful about it. We are trying to see what development has meant in Pakistan in the past half century. As there are so many dimensions that the subject has now come to have since its rather simplistic beginnings, we thought the Golden Jubilee of Pakistan to be an appropriate occasion for such stock-taking.


Author(s):  
C. Daniel Batson

This book provides an example of how the scientific method can be used to address a fundamental question about human nature. For centuries—indeed for millennia—the egoism–altruism debate has echoed through Western thought. Egoism says that the motivation for everything we do, including all of our seemingly selfless acts of care for others, is to gain one or another self-benefit. Altruism, while not denying the force of self-benefit, says that under certain circumstances we can care for others for their sakes, not our own. Over the past half-century, social psychologists have turned to laboratory experiments to provide a scientific resolution of this human nature debate. The experiments focused on the possibility that empathic concern—other-oriented emotion elicited by and congruent with the perceived welfare of someone in need—produces altruistic motivation to remove that need. With carefully constructed experimental designs, these psychologists have tested the nature of the motivation produced by empathic concern, determining whether it is egoistic or altruistic. This series of experiments has provided an answer to a fundamental question about what makes us tick. Framed as a detective story, the book traces this scientific search for altruism through the numerous twists and turns that led to the conclusion that empathy-induced altruism is indeed part of our nature. It then examines the implications of this conclusion—negative implications as well as positive—both for our understanding of who we are as humans and for how we might create a more humane society.


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