Standard SOS Research Articles

A modification of I-SOS: performance analysis to large scale functions

SOS is a global optimization algorithm, based on nature, and is utilized to execute the various complex hard optimization problems. Be that as it may, some basic highlights of SOS, for example, pitfall among neighborhood optima and weaker convergence zone should be upgraded to discover better answers for progressively intricate, nonlinear, many optimum solution type problems. To diminish these deficiencies, as of late, numerous analysts increase the exhibition of the SOS by designing up a few changed form of the SOS. This paper suggests an improved form of the SOS to build up an increasingly steady balance between discovery and activity cores. This technique uses three unique procedures called adjusted benefit factor, altered parasitism stage, and random weighted number-based search. The technique is referred to as mISOS and tested in a popular series of twenty classic benchmarks. The dimension of these problems is considered to be hundred to monitor the impact of the suggested technique on the versatility of the test problems. Also, some real-life optimization problems are solved with the help of the proposed mISOS. The results investigated based on three different way and theses are statistical measures, convergence, and statistical analyses. The comparison of results of the mISOS with the standard SOS, SOS variants, and certain other cutting-edge algorithms shows its improved search performance.

Current Perspective of Symbiotic Organisms Search Technique in Cloud Computing Environment: A Review

Nature-inspired algorithms in computer science and engineering are algorithms that take their inspiration from living things and imitate their actions in order to construct functional models. The SOS algorithm (symbiotic organisms search) is a new promising metaheuristic algorithm. It is based on the symbiotic relationship that exists between different species in an ecosystem. Organisms develop symbiotic bonds like mutualism, commensalism, and parasitism to survive in their environment. Standard SOS has since been modified several times, either by hybridization or as better versions of the original algorithm. Most of these modifications came from engineering construction works and other discipline like medicine and finance. However, little improvement on the standard SOS has been noticed on its application in cloud computing environment, especially cloud task scheduling. As a result, this paper provides an overview of SOS applications in task scheduling problem and suggest a new enhanced method for better performance of the technique in terms of fast convergence speed.

A new chaos and global competitive ranking-based symbiotic organisms search algorithm for solving reactive power dispatch problem with discrete and continuous control variable

In this paper, optimal reactive power dispatch problem (ORPD) is solved by using a new chaos and global competitive ranking-based symbiotic organisms search algorithm (A-CSOS). SOS is an effective meta-heuristic algorithm, especially for optimization problems with continuous variable, with important features such as the absence of any user-defined algorithmic parameters and the easily applicable. However, some essential features of SOS such as trap into local optima and slow convergence problems need to be improved in order to find better solutions for more complex, nonlinear, multi-modal optimization problems such as ORPD. In this study, to solve ORPD and enhance the capability of the standard SOS even further, A-CSOS algorithm is developed. To test the performance of the developed algorithm in ORPD, the both SOS and the proposed A-CSOS are applied to the two different objective functions including power loss minimization and total voltage deviation minimization in IEEE 57-, 118-, 300-bus power systems. According to the results of ten different test cases, the proposed method gives better solutions up to 15.3% and 40.52% than the state-of-art algorithms and SOS, respectively. Moreover, the convergence performance of A-CSOS is considerably better than all tried algorithms. The effectiveness of A-CSOS for solving ORPD and other complex constrained optimization problems is proofed by this study.

An improved meta-heuristic method to maximize the penetration of distributed generation in radial distribution networks

This paper proposes a novel scheme based on an improved meta-heuristic method to determine the optimal number of distributed generation (DG) units to be installed in distribution networks for maximum DG penetration. The proposed meta-heuristic method is the quasi-oppositional chaotic symbiotic organisms search (QOCSOS) algorithm, which is the improved version of the original SOS algorithm. QOCSOS integrates two search strategies including quasi-opposition-based learning and chaotic local search into SOS to achieve better performance. In this study, QOCSOS was implemented to find the optimal number, location, size, and power factor of DG units considering different values of DG power factor (unity and non-unity), with the objective of maximum real power loss reduction. The effectiveness of the proposed method was validated on the standard IEEE radial distribution networks including 33, 69, and 118-bus test networks. The results obtained by QOCSOS were compared to those from other methods available in the literature and the standard SOS algorithm. Comparative results revealed that QOCSOS obtained better solutions than other compared methods, and performed greater than SOS. Accordingly, QOCSOS can be a very favourable method to cope with the optimal DG placement problem.

An SOS Regulon under Control of a Noncanonical LexA-Binding Motif in the Betaproteobacteria.

The SOS response is a transcriptional regulatory network governed by the LexA repressor that activates in response to DNA damage. In the Betaproteobacteria, LexA is known to target a palindromic sequence with the consensus sequence CTGT-N8-ACAG. We report the characterization of a LexA regulon in the iron-oxidizing betaproteobacterium Sideroxydans lithotrophicus. In silico and in vitro analyses show that LexA targets six genes by recognizing a binding motif with the consensus sequence GAACGaaCGTTC, which is strongly reminiscent of the Bacillus subtilis LexA-binding motif. We confirm that the closely related Gallionella capsiferriformans shares the same LexA-binding motif, and in silico analyses indicate that this motif is also conserved in the Nitrosomonadales and the Methylophilales. Phylogenetic analysis of LexA and the alpha subunit of DNA polymerase III (DnaE) reveal that the organisms harboring this noncanonical LexA form a compact taxonomic cluster within the Betaproteobacteria. However, their lexA gene is unrelated to the standard Betaproteobacteria lexA, and there is evidence of its spread through lateral gene transfer. In contrast to other reported cases of noncanonical LexA-binding motifs, the regulon of S. lithotrophicus is comparable in size and function to that of many other Betaproteobacteria, suggesting that a convergent SOS regulon has reevolved under the control of a new LexA protein. Analysis of the DNA-binding domain of S. lithotrophicus LexA reveals little sequence similarity with that of other LexA proteins targeting similar binding motifs, suggesting that network structure may limit site evolution or that structural constrains make the B. subtilis-type motif an optimal interface for multiple LexA sequences. Understanding the evolution of transcriptional systems enables us to address important questions in microbiology, such as the emergence and transfer potential of different regulatory systems to regulate virulence or mediate responses to stress. The results reported here constitute the first characterization of a noncanonical LexA protein regulating a standard SOS regulon. This is significant because it illustrates how a complex transcriptional program can be put under the control of a novel transcriptional regulator. Our results also reveal a substantial degree of plasticity in the LexA recognition domain, raising intriguing questions about the space of protein-DNA interfaces and the specific evolutionary constrains faced by these elements.

INFLUENCE OF SILICON LAYER PROPERTIES ON CAPACITANCE PARAMETERS OF MIS/SOS-STRUCTURES

The influence of the epitaxial layer features and so silicon-sapphire interface in SOS-structures on capacitance parameters of MIS-structures formed on SOS with submicron silicon layers were investigated in this article. Both standard SOS-structures with 0.3 μk silicon n-type layer and analog SOS-structures with the blastic silicon layer amorphizated by the oxygen ion implantation with following high-temperature annealing. The two different types of test MIS-structures with 30 nm gate oxide, polysilicon gate and metallic contacts were fabricated. The strong difference in the capacitance characteristics for standard SOS and SOS with recrystallization silicon layer was disclosed in depletion region. It was revealed the strong frequency dependence of capacitance characteristics for the test MIS-structures formed on almost all SOS-structures. It was shown that the character of the test structures C — V -curves were defined by dimension and configuration of the silicon layer as well as the deep compensate levels concentration in layer near silicon-sapphire interface. Particularly it was shown that big changes of the frequency-capacitance dependences at transition from the tests formed on standard SOS to tests on SOS with blastic silicon layer were determined by great concentration of deep compensate centers in layer near interface for standard SOS. It was shown that the recrystallization of silicon layer by oxygen ion implantation may lead to appearance of the centers, formed donor levels into silicon band gap and appearance of the frequency-capacitance dependences in depletion region of such SOS-structures.

Synthesis of nanospheres-on-microsphere silica with tunable shell morphology and mesoporosity for improved HPLC.

Core-shell particles have a wide range of applications. Most of the core-shell particles are prepared in two or multiple steps. Core-shell silica microspheres, with solid core and porous shell, have been used as novel packing materials in recent years for highly efficient liquid chromatography separation with relatively low back-pressure. These core-shell silica microspheres are usually prepared by the time-consuming layer-by-layer technique. Built on our previous report of one-pot synthesis of core-shell nanospheres-on-microspheres (termed as SOS particles for "spheres-on-spheres"), we describe here a two-stage synthesis for the introduction of shell mesoporosity into SOS particles with tunable shell morphology by co-condensation of tetraethyl orthosilicate (TEOS) with 3-mercaptopropyltrimethoxysilane (MPTMS) in the presence of surfactant in the second stage. With MPTMS as the primary precursor at the first stage, some other silica precursors (apart from TEOS) are also employed at the second stage. Expansion of the surfactant-templated mesopores with swelling agents during the reaction and by hydrothermal postsynthesis treatment is then performed to allow the pore sizes (> 6 nm) suitable for separation of small molecules in liquid chromatography. Compared to the standard SOS silica (both the nanospheres and microspheres contain nearly no mesopores), the introduction of mesoporosity into the nanosphere shell increases the separation efficiency of small molecule mixtures by 4 times as judged by the height equivalent plate number, while the separation of protein mixtures is not negatively affected.

Quantitative ultrasound measurements of bone strength in female adolescent idiopathic scoliosis patients

Methods This study was approved by the Human Research Ethic Committee of the School of Medicine, Jiaotong University, China. Eighty nine untreated female AIS patients were recruited in this study. The age range was from 10 to 16 years. Those who were using calcium supplements and those who had history of bone diseases were excluded from the study. The diagnoses of all AIS were confirmed by radiography based on American College of Radiology Guidelines and Recommendations. Cobb’s angles ranged from 10-52° (average 27.13°). The types of scoliosis included thoracic, lumbar, thoracolumbar and double curvatures. Patients’ menstrual conditions and family history were also taken in consideration. SOS was measured (by Sunlight omnisense) in the distal 1/3 of the radial bones. Data were compared to age and gender-matched norms (standard SOS value provided by Sunlight system). Results Radial SOS was significantly reduced in AIS patients compared to non-AIS subjects (P < 0.01); the radial SOS was also correlated to the age of the onset of menstrual cycle (lower in pre-menstrual cycle patients, 3626.92±124.35 vs. 3702.68±192.23, P<0.05). No significant correlations were found among the type of curvatures, the degree of Cobb’s angle, family history and bone SOS (P < 0.05).

Certifying convergence of Lasserre’s hierarchy via flat truncation

Consider the optimization problem of minimizing a polynomial function subject to polynomial constraints. A typical approach for solving it globally is applying Lasserre’s hierarchy of semidefinite relaxations, based on either Putinar’s or Schmüdgen’s Positivstellensatz. A practical question in applications is: how to certify its convergence and get minimizers? In this paper, we propose flat truncation as a certificate for this purpose. Assume the set of global minimizers is nonempty and finite. Our main results are: (1) Putinar type Lasserre’s hierarchy has finite convergence if and only if flat truncation holds, under some generic assumptions; the same conclusion holds for the Schmüdgen type one under weaker assumptions. (2) Flat truncation is asymptotically satisfied for Putinar type Lasserre’s hierarchy if the archimedean condition holds; the same conclusion holds for the Schmüdgen type one if the feasible set is compact. (3) We show that flat truncation can be used as a certificate to check exactness of standard SOS relaxations and Jacobian SDP relaxations.

Tile Formats for Located and Mobile Systems

Standard SOS formats are limited in their ability to define the operational semantics of process calculi with concurrency, causality, and mobility, and with bound names and name generation mechanisms. In this paper we describe a general approach, based on the tile model, to the definition of the operational semantics of process calculi. By providing tile systems for located CCS and asynchronous π -calculus we demonstrate that the proposed approach is more suited than SOS to provide a uniform treatment of concurrency and mobility within a compositional framework.

Parameterized Structured Operational Semantics

A generalization of De Simone format, where labels of transitions are structured actions, is presented. This provides a parameterized SOS framework where several paradigms of the observational semantics of process calculi can be uniformly handled. Moreover, standard algebraic techniques provide the formal machineries to relate the different semantics. It is also shown that much of the meta results developed for standard SOS format extend to this parameterized context.

A π-calculus with explicit substitutions

A new formulation of the π-calculus, where name instantiation is handled explicitly via the introduction of a suitable combinator, is presented. The bisimulation semantics originally developed for the π-calculus are retrieved by giving the description of the corresponding strategies for name instantiation. The explicit handling of name instantiation allows us to reduce the π-calculus transitional semantics to a standard SOS framework. Hence, π-calculus bisimulation models can take fully advantage of the SOS meta-theory developed for ‘static’ process calculi. For instance, complete axiomatic characterizations of π-calculus bisimulation equivalences can be automatically derived by turning SOS rules into equations. This formulation of the π-calculus is very promising for the development of semantic-based automatic verification tools.

Assessment of oxidative DNA damage in the oxyR-deficient SOS chromotest strain Escherichia coli PQ300.

The SOS chromotest is a simple short-term genotoxicity assay measuring the induction of gene sfiA in Escherichia coli K-12. The recent availability of SOS tester strains with additional mutations in DNA repair or protection systems allows testing of DNA damaging compounds for genotoxic specificity. E. coli PQ300 differs from the standard SOS tester strain PQ37 in that it contains an additional mutation in gene oxyR that renders it more sensitive to oxidative genotoxins. The generation of reactive oxygen intermediates (ROI) by hydroperoxides (H2O2, t-butyl hydroperoxide, cumene hydroperoxide), gamma-radiation, glucose oxidase, and xanthine oxidase resulted in a more vigorous SOS response in strain PQ300 compared to strain PQ37. PQ300 was also more sensitive than PQ37 for the detection of reducing agents such as ascorbic acid, cysteine, and glutathione, which also alter the redox status of the bacterial cells. However, intercalating agents (adriamycin, bleomycin, and mitomycin C) and the UV- and radiomimetic compound 4-nitroquinoline-1-oxide whose DNA damaging potential are known also to involve ROI did not show significant differences between strains PQ37 and PQ300. It is concluded that the oxyR-deficient strain PQ300 is useful for detecting certain classes of genotoxins that change the oxidative/antioxidative balance of tester bacteria in the SOS chromotest.

LASOS—laser annealed silicon on sapphire

Laser annealing techniques were successfully incorporated into standard MOS/SOS processing to increase transistor channel mobility and processing yield. Silicon islands were photolithographically defined and chemically etched (by KOH) on standard SOS wafers. The islands were exposed to radiation from an excimer laser (λ = 2490 Å) having a pulse duration of 25 ns, a beam size in the range of 0.1-0.2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and an energy density in the range of 0.5 - 1.0 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Using standard processing techniques MOS transistors were fabricated and characterized. It was found that exposure at an energy density of ∼0.80 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> results in rounding the Si island edges, thus eliminating the "V"-shaped groove profile of the gate oxide and improving Al step coverage. The electrical characteristics of MOS transistors fabricated over laser annealed islands exhibited a 30-percent increase in channel mobility with a small negative shift (<0.2 V) in the transistor threshold voltage.

Application of laser annealing techniques to increase channel mobility in silicon on sapphire transistors

Laser annealing techniques were successfully incorporated into standard metal-oxide-semiconductor silicon-on-sapphrie (MOS/SOS) processing to increase transistor channel mobility. Silicon islands were photolithographically defined and chemically etched (by KOH) on standard SOS wafers. The islands were exposed to radiation from an excimer laser (λ=2490 Å) having a pulse duration of 25 nsec, a beam size in the range 0.1–0.2 cm2, and an energy density in the range 0.5–1.0 J/cm2. Using standard processing techniques, MOS transistors were fabricated and characterized. It was found that MOS transistors fabricated over islands exposed to a beam having an energy density of 0.8 J/cm2 exhibit a 30% increase in channel mobility.