Weak Function Research Articles

Input-to-state stability for discrete-time switched systems by using Lyapunov functions with relaxed constraints

<abstract><p>In this paper, input-to-state stability (ISS) is investigated for discrete-time time-varying switched systems. For a switched system with a given switching signal, the less conservative assumptions for ISS are obtained by using the defined weak multiple ISS Lyapunov functions (WMISSLFs). The considered switched system may contain some or all subsystems which do not possess ISS. Besides, for an ISS subsystem the introduced Lyapunov function could be increasing along the trajectory of the subsystem without input at some moments. Then for a switched system under any switching signal, the relaxed sufficient constraints for ISS are attained by using the defined weak common ISS Lyapunov functions. For this case, each subsystem of the considered system must be ISS. The proposed function may be increasing along the trajectory of each ISS subsystem of the considered system without input at some instants. The relationship between WMISSLFs for a switched system and the defined weak multiple Lyapunov functions for this switched system without input is set up. Three numerical examples are investigated to display the usefulness of the principal outcomes. According to the main conclusions, an intermittent controller is applied to ensure ISS for a discrete-time disturbed Chua's chaotic system.</p></abstract>

Chromatographic Determination of the Chemical Composition of Apple Chips Extract

The qualitative composition of the extraction of dried apples of green (Golden, Mutsu) and red (Florina, Aidared) varieties by gas-liquid chromatography with mass-selective detection has been established. The chips were obtained by convective drying at the temperature of +(63–70) °С to a final dampness of 6–8 %. Water-alcohol extract was analyzed on the Shimadzu GCMS-QP2020 gas chromatomas-spectrometer with a full ion current (SCAN), the scanning range of 40–1000 Da. The peaks were processed and identified based on the open source data (NIST 2017 and Wiley 5th Edition). In the studied samples of apple extraction, 30 characteristic components were found, among which carbohydrates predominate – mono- and disaccharides, their derivatives and products of dehydration and oxidation. The apple extract contains higher fatty acids: n-hexadecanoic acid, tetradecanoic acid, octadecanoic acid, oleic acid. Compounds formed as a result of drying (5-hydroxymethylfurfural, 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyrane-4-one), as well as flavonoids and anthocyanins, which perform antioxidant and weak antibiotic functions in the body, were identified. Vitamins could not be determined using this method.

Board Diversity in Financial Distress Companies in Malaysia

The declining financial performance is often associated with the weak function of the board’s role in the companies. The number of publicly listed companies categorised as Practice Note (PN17) by Bursa Malaysia shows an increase due to financial distress. This study examines the effectiveness of board diversity in financially distressed companies categorised as PN17 by Bursa Malaysia using content analysis of annual reports for five years as secondary data. The characteristics of board diversity include board professionalism and a politically connected board. In contrast, the proxy of financial distress will be measured using Altman Z Score for multiple regressions in evaluating financial performance ratios. Implementing the Malaysian Code of Corporate Governance (MCCG) in 2021 also assessed the effectiveness of board diversity and its interaction with financial distress. The findings from this study are expected to provide evidence that board diversity may have a significant relationship with financially distressed companies. Overall, this study may assist investors, practitioners, and external regulators in monitoring the company by assessing the effectiveness of board diversity from being classified as a financially distressed company.

Warm dark matter constraints using Milky Way satellite observations and subhalo evolution modeling

Warm dark matter (WDM) can potentially explain small-scale observations that currently challenge the cold dark matter (CDM) model, as warm particles suppress structure formation due to free-streaming effects. Observing small-scale matter distribution provides a valuable way to distinguish between CDM and WDM. In this work, we use observations from the Dark Energy Survey and PanSTARRS1, which observe 270 Milky-Way satellites after completeness corrections. We test WDM models by comparing the number of satellites in the Milky Way with predictions derived from the Semi-Analytical SubHalo Inference ModelIng (SASHIMI) code, which we develop based on the extended Press-Schechter formalism and subhalos' tidal evolution prescription. We robustly rule out WDM with masses lighter than 4.4 keV at 95% confidence level for the Milky-Way halo mass of $10^{12} M_\odot$. The limits are a weak function of the (yet uncertain) Milky-Way halo mass, and vary as $m_{\rm WDM}>3.6$-$5.1$ keV for $(0.6$-$2.0) \times 10^{12} M_\odot$. For the sterile neutrinos that form a subclass of WDM, we obtain the constraints of $m_{\nu_s}>11.6$ keV for the Milky-Way halo mass of $10^{12} M_{\odot}$. These results based on SASHIMI do not rely on any assumptions of galaxy formation physics or are not limited by numerical resolution. The models, therefore, offer a robust and fast way to constrain the WDM models. By applying a satellite forming condition, however, we can rule out the WDM mass lighter than 9.0 keV for the Milky-Way halo mass of $10^{12} M_\odot$.

Power consumption in a moving baffle oscillatory baffled reactor: A CFD study

AbstractOscillatory baffled reactors (OBRs) can perform high‐intensity mixing under low power consumption, and thus are viable replacements for stirred tank reactors in biological, chemical, and polymer processes. This study simulated the flow inside a moving baffle OBR with single orifice baffles using computational fluid dynamics (CFD). The effect of operational and geometrical parameters along with the fluid density and viscosity on average power consumption and maximum power consumption was investigated, and appropriate correlations for both average and maximum power consumption were obtained. It was found that average and maximum power consumption are independent of viscosity, and amplitude has a greater impact on maximum power consumption than on average power consumption. These correlations were then compared with available power models (that showed an acceptable level of discrepancies) in the literature. Lower power consumption values obtained from CFD results compared to those obtained from quasi‐steady state model (QSM) and eddy enhancement model (EEM) models (developed for stationary baffle OBRs) under the same operating conditions, along with higher axial dispersion of moving baffle OBRs compared to stationary baffle types under the same operating conditions, indicated that a moving baffle OBR is a more efficient mixing device than a stationary baffle OBR in terms of power consumption. The ratio of average power consumption to maximum power consumption was proven to be independent of the type of fluid and a very weak function of oscillation frequency.

The Interplay of Emotions, Executive Functions, Memory and Language: Challenges for Refugee Children

Refugee children tend to show low emotional well-being and weak executive functions that may have consequences on language and therefore complicate a potential diagnosis of Developmental Language Disorder (DLD) in this population. We assessed the performance of 140 children living in Switzerland aged 5 to 8 (20 monolinguals, 86 non-refugee bilinguals, 34 refugee bilinguals) on LITMUS language tasks (nonword repetition, sentence repetition, parental questionnaire), standardized language tasks, memory and executive function tasks. Parents also filled in the Child Behavior Checklist providing a measure of their child’s emotional well-being. Results indicate that refugee children are more emotionally vulnerable and show weaker performance in memory and executive functions tasks compared to non-refugee children, in line with the existing literature. Moreover, when compared to non-refugee bilingual children with similar length of exposure to French, refugee children are disadvantaged on all language tasks. Whereas emotional well-being does not predict language performance, memory and executive functions show up as predictors of both LITMUS and standardized language tasks, although in an unsystematic way. It is concluded that refugee children are at risk across the board and that a better understanding of the complex interplay between well-being, executive functions, memory and language is needed in order to build more appropriate diagnostic tools for these children.

Bilevel optimization for the reorganization of inland river ports: A niche perspective

To address the problems of duplicate construction, disorderly competition, small scale, and weak functionality, we examine the reorganization optimization of an inland river port group to realize its coordinated development. Considering port customers' decision-making behaviors, we propose a bilevel programming model for inland river port group reorganization based on niche theory. More specifically, an upper-level model is used to develop a reorganization plan, including the inland river port spatial layout and expansion extent, to maximize the value contributed by the port group to its region and industry and minimize the competition among the ports from the perspective of port management. More specifically, two upper-level objectives can be creatively measured by niche breadth and niche overlap. A lower-level model oriented to port customers aims to reduce their respective logistics costs by designing a transportation plan and providing feedback to the upper-level model to facilitate adjustments for port group reorganization. Since the dynamic interaction between the upper- and lower-level models significantly increases model complexity, we develop a hybrid heuristic algorithm by incorporating a genetic algorithm and an exact solution method. To verify the applicability of the proposed model and the efficiency of the developed hybrid approach, we conduct a series of numerical experiments on a real-world case study concerning Jining City, Shandong Province, China. Our case study also provides managerial insights into investment scale, land-use intensification, and the balance of planning objectives that may be useful for port managers.

Numerical Simulation Study on Interactions between the Wave and Newborn Sandbank in the Xisha Islands of the South China Sea

As a unique landform in the island and reef area, the newborn sandbank is not only the initial stage of island development, but also has a rapid evolution and a complex dynamic mechanism. However, the dynamic geomorphology mechanism of the newborn sandbank is still lacking extensive study and direct evidence of the interaction process between the marine dynamics and the newborn sandbank geomorphology. Therefore, in order to reveal the interaction mechanisms between marine dynamics and newborn sandbanks, a newborn sandbank in the sea area of the Xisha Islands, in the South China Sea, has been selected as the focus of this research. The method of numerical simulation was used to discuss and analyze the wave field characteristics around the newborn sandbank and their impacts on the sandbank’s migration and development. The results show that: (1) The islands and reefs have significant refraction, diffraction, and energy dissipation effects on waves, and the newborn sandbank has the same effect, but with a weaker function. The wave height around the reef islands reduced by approximately 60–67% in dominated and strong wave directions. At the same time, the wave height attenuation in the wave shadow zone, behind the newborn sandbank, can reach approximately 27–33%. (2) Wind is important for the evolution of wave fields; in particular, when the wind speed exceeds grades four and five, the effect of the wind on the waves is particularly significant, causing the winds to control the wave characteristics around the islands and newborn sandbanks. This results in significant seasonal differences in wave fields within the sea area. (3) The wave direction primarily controls the migration direction of the newborn sandbank, and the wave height primarily controls the migration speed and distance. After one month of wave action in the strong wave direction, the maximum eastward deposition length was approximately 50 m. After one month of wave action in the dominated wave direction, the maximum eastward deposition length was approximately 60 m. Therefore, the topography of the newborn sandbank affects the wave propagation, meanwhile, the wave conversely determines migration and development of the newborn sandbank in a short term. The dynamic geomorphology action between the wave and newborn sandbank is a fast two-way process, and occurs not only during storms or the winter monsoon, but also during other, more common, weather events.

Evaluasi Pelaksanaan Rencana Kerja DPRD Kota Serang Tahun 2019

The Work Plan of the Regional House of Representatives (DPRD) does not only contain planning for program activities but is also a manifestation of the implementation functions, that are the function of formatting the regional regulations, budget function, and monitoring function. However, in 2019 there were presidential and legislative elections held simultaneously for the first time in Indonesia. Logically, this will have an impact for the leaders and members of the DPRD who are the region political actors in carrying out their duties and functions as specified in the work plan. Moreover, in that year there were two periods of DPRD membership, the 2014-2019 term and the 2019-2024 term. This research aims to evaluate the implementation work plan of the Serang City Regional House of Representatives in 2019 which is focused on the implementation of the program activities and functions. Researchers use evaluative research design with a qualitative descriptive approach which was developed based on the evaluation criteria presented by William N. Dunn. The findings of this study explain that the work plan activity program is carried out according to the schedule set by the Badan Musyawarah considering the election stages of the KPU and adjustments to the political agenda of the leaders and members of the DPRD. Meanwhile, in the implementation of DPRD functions in 2019, the weakest function is the monitoring function. It is because the monitoring that has been evaluated so far is a field visit activity or often also called an inspection. Whereas monitoring can also take the form of work meetings, meetings to discuss regional regulations, or other activities that actually can also be in the form of monitoring the performance of local governments.

A Category Theoretic View of Contextual Types: From Simple Types to Dependent Types

We describe the categorical semantics for a simply typed variant and a simplified dependently typed variant of Cocon , a contextual modal type theory where the box modality mediates between the weak function space that is used to represent higher-order abstract syntax (HOAS) trees and the strong function space that describes (recursive) computations about them. What makes Cocon different from standard type theories is the presence of first-class contexts and contextual objects to describe syntax trees that are closed with respect to a given context of assumptions. Following M. Hofmann’s work, we use a presheaf model to characterise HOAS trees. Surprisingly, this model already provides the necessary structure to also model Cocon . In particular, we can capture the contextual objects of Cocon using a comonad ♭ that restricts presheaves to their closed elements. This gives a simple semantic characterisation of the invariants of contextual types (e.g. substitution invariance) and identifies Cocon as a type-theoretic syntax of presheaf models. We further extend this characterisation to dependent types using categories with families and show that we can model a fragment of Cocon without recursor in the Fitch-style dependent modal type theory presented by Birkedal et al.

Weak Galerkin finite element method for linear elasticity interface problems

In this paper, we apply a weak Galerkin finite element method to a linear elasticity interface model. Since the solution may become discontinuous while crossing the interface, we first discretize the model by double-valued weak functions on the interface. Then, in order to facilitate theoretical analysis and algorithm implementation, we substitute interface conditions into the weak Galerkin formulation and construct a weak Galerkin method with single-valued functions on the interface. Furthermore, we prove the well-posedness of the weak Galerkin scheme and derive a priori error estimates in energy norm and L2 norm. Finally, we present some numerical experiments to demonstrate the efficiency and the locking-free property of our method.

Artificial neural network models of burst strength for thin-wall pipelines

Burst strength is critical to pipeline design, operation, and integrity management. The Barlow formula with the ultimate tensile stress (UTS) was often used to estimate burst strength of line pipes. To consider the plastic flow effect of pipeline steels, an average shear stress yield criterion was proposed, and the associated Zhu-Leis solution of burst strength was obtained for defect-free pipelines in term of UTS and strain hardening exponent, n, of materials. The Zhu-Leis solution was validated by more than 100 burst tests for various pipeline steels. The Zhu-Leis solution, when normalized by the Barlow strength, is a function of strain hardening rate, n, only. In contrast, experimental burst test data, when normalized by the Barlow strength, are a weak function of UTS and pipe diameter to thickness ratio D/t, in addition to be the function of n. Due to the difficulty of obtaining a closed-from solution using three-parameter regression, machine learning technology is adopted to develop alternative models of burst strength based on a large database of full-scale burst tests. In comparing to the regression, the machine learning method works well for both single and multiple parameters by introducing an artificial neural network (ANN), activation functions and learning algorithm for the network to learn from training data and then make predictions. Three ANN models were developed in this paper for predicting the burst strength of defect-free pipelines. Model 1 has one input variable and one hidden layer with three neurons; Model 2 has three input variables and one hidden layer with five neurons; and Model 3 has three input variables and two hidden layers with three neurons for the first hidden layer and two neurons for the second hidden layer. These three ANN models were then validated by the full-scale test data and evaluated through comparison with the Zhu-Leis solution and the linear regression results. On this basis, the best ANN model was recommended.

Verifiable Delay Function and Its Blockchain-Related Application: A Survey.

The concept of verifiable delay functions has received attention from researchers since it was first proposed in 2018. The applications of verifiable delay are also widespread in blockchain research, such as: computational timestamping, public random beacons, resource-efficient blockchains, and proofs of data replication. This paper introduces the concept of verifiable delay functions and systematically summarizes the types of verifiable delay functions. Firstly, the description and characteristics of verifiable delay functions are given, and weak verifiable delay functions, incremental verifiable delay functions, decodable verifiable delay functions, and trapdoor verifiable delay functions are introduced respectively. The construction of verifiable delay functions generally relies on two security assumptions: algebraic assumption or structural assumption. Then, the security assumptions of two different verifiable delay functions are described based on cryptography theory. Secondly, a post-quantum verifiable delay function based on super-singular isogeny is introduced. Finally, the paper summarizes the blockchain-related applications of verifiable delay functions.

On the algebraic immunity of direct sum constructions

In this paper, we study sufficient conditions to improve the lower bound on the algebraic immunity of a direct sum of Boolean functions. We exhibit three properties on the component functions such that satisfying one of them is sufficient to ensure that the algebraic immunity of their direct sum exceeds the maximum of their algebraic immunities. These properties can be checked while computing the algebraic immunity and they allow to determine better the security provided by functions central in different cryptographic constructions such as stream ciphers, pseudorandom generators, and weak pseudorandom functions. We provide examples for each property and determine the exact algebraic immunity of candidate constructions.

On weak lensing response functions

We introduce the response function approach to model the weak lensing statistics in the context of separate universe formalism. Numerical results for the RFs are presented for various semi-analytical models that includes perturbative modelling and variants of halo models. These results extend the recent studies of the Integrated Bispectrum and Trispectrum to arbitrary order. We find that due to the line-of-sight projection effects, the expressions for RFs are not identical to the squeezed correlation functions of the same order. We compute the RFs in three-dimensions using the spherical Fourier-Bessel formalism which provides a natural framework for incorporating photometric redshifts, and relate these expressions to tomographic and projected statistics. We generalise the concept of k-cut power spectrum to k-cut response functions. In addition to response functions, we also define their counterparts in real space, since they are easier to estimate from surveys with low sky-coverage and non-trivial survey boundaries.

Isolated dorsal dislocation of the 5th carpometacarpal joint; a missed injury

Introduction: 5th carpometacarpal (CMC) joint dislocations of the wrist region are very rare and easily overlooked injuries. In this type of injury, which causes serious functional problems in the hand if not treated appropriately, closed methods are generally used in the treatment. In this study, we present a case with fracture-dislocation of the 5th CMC joint. 
 Case: Fracture-dislocation of the 5th CMC joint of a 25-year-old patient who was admitted to the emergency department due to wrist pain was not noticed. The diagnosis was made during the follow-up of the patient, and the joint was reduced with closed method and fixed with a K wire. No serious problems were encountered in the patient's controls.
 Conclusion: Undiagnosed 5th CMC joint dislocation disrupts the transverse and longitudinal arches of the hand, so the patient has a weak and painful gripping function. Radiological findings may be unclear on anterior-posterior and lateral views, and additional images may be obtained if in doubt.

Two‐order superconvergence for a weak Galerkin method on rectangular and cuboid grids

AbstractThis article introduces a particular weak Galerkin (WG) element on rectangular/cuboid partitions that uses th order polynomial for weak finite element functions and th order polynomials for weak derivatives. This WG element is highly accurate with convergence two orders higher than the optimal order in an energy norm and the norm. The superconvergence is verified analytically and numerically. Furthermore, the usual stabilizer in the standard weak Galerkin formulation is no longer needed for this element.

Differential evolutionary cuckoo-search-integrated tabu-adaptive pattern search (DECS-TAPS): a novel multihybrid variant of swarm intelligence and evolutionary algorithm in architectural design optimization and automation

Abstract One of the critical limitations in architectural design optimization (ADO) is slow convergence due to high-dimensional and multiscale variables. For the rapid and optimal digital prototyping of architectural forms, this paper proposes a novel metaheuristic optimization technique that hybridizes standard low-level algorithms: the differential evolutionary cuckoo-search-integrated tabu-adaptive pattern search (DECS-TAPS). We compared DECS-TAPS to 10 major standard algorithms and 31 hybrids through 14 benchmark tests and investigated multi-objective ADO problems to prove the computational effectiveness of multiple algorithm hybridization. Our findings show that DECS-TAPS is vastly efficient and superior to the covariance matrix adaptation evolution strategy algorithm in multifunnel and weak structural functions. The global sensitivity analysis demonstrated that integrating multiple algorithms is likely conducive to lowering parameter dependence and increasing robustness. For the practical application of DECS-TAPS in building simulation and design automation, Zebroid—a Rhino Grasshopper (GH) add-on—was developed using IronPython and the GH visual scripting language.

Positive-Bias-Temperature-Instability Induced Random-Trap-Fluctuation Enhanced Physical Unclonable Functions on 14-nm nFinFETs

We report one sort of weak physical unclonable functions (PUFs) composed of 14-nm nFinFETs with entropy of the random-trap-fluctuation (RTF). After the positive-bias-temperature-instability (PBTI) stress at high temperatures (85 °C ~ 150 °C), the generation of abundant random traps at the interface of gate-dielectric layers and channel efficiently improves cryptographic parameters of nFinFET-PUFs. Results show that bit-error-rates of the MOSAIC plots reduce to 1.4%; average values/standard-deviation of the inter- and intra- Hamming-distance reach 50.28%/1.7% and 0.38%/0.42%, respectively. This work provides an implacable technique to boost characteristics of weak PUFs through combinations of device-reliability and cryptography.

Experimental study of the oblique impact and ricochet characteristics of cylindrical fragments

When the casing charge exploded near or inside a steel installation such as a ship or plant, part of the fragments would impact the target plate and ricochet. Plastic deformation occurs on both the fragment and target plate during the oblique impact, in which the direction and velocity of fragments change. The ricochet of fragments would change the damage range, which cannot be predicted by previous theories. In our experiment, cylindrical fragments were used to impact target plates under different impact velocities and angles, and the target plates are made of marine steel 921A and commonly used Q345B, which are the two most commonly used steels for ships and steel installations. The empirical formulae of ricochet velocity and angle for two target plates were obtained, which were applicable to the positive ricochet. The ricochet velocity increased with the increase in impact velocity and angle, but the ricochet angle only increased with the increase in impact angle. In addition, the ricochet velocity increased with the increase in the hardness of target plate when the impact angle was less than 40° due to the deformation of the target plate, the ricochet angle increased with the increase in the hardness of target plate since the pile-up effect would increase the deflection, causing the ricochet angle decreased. The fragment mass loss model was obtained based on the experimental data, which is a strong function of impact velocity but a weak function of impact angle. With the increase in impact angle, the plastic deformation of fragments gradually decreased, the target plate changed from plastic compression deformation to shear deformation, the deformation energy of target plate changed from volumetric energy to more shear strain energy, and the impact crater became shallower. With the increase in impact velocity, the plastic deformation of fragments increased, the inertial resistance of target plate increased, the impact crater on the target surface became larger and deeper, and then only the depth of impact crater increased when the impact velocity reached a certain extent. The plastic deformation of target plate decreased with the increase in the hardness. The proposed formulae and model can provide guidance for the fragment damage range evaluation and equipment protection.