Simple Rules Research Articles

Tunable magnetic anisotropy of Os-Ru dimer on 2D transition metal chalcogenides substrates

The precise manipulation of atoms enables the creation of distinct materials from the bottom up to construct devices with breakthrough performance, especially in the field of quantum technologies. A large magnetic anisotropy energy (MAE) is important to realize bit storage of information in magnetic memory devices. As the smallest magnetic nanostructure, substrate-supported transition metal dimers are potential atomic-scale storage medium to obtain large MAEs. Using high-throughput first-principles calculations, we have performed a systematic investigation of the MAE of 76 heterodimensional systems consisting of zero-dimensional Os-Ru dimer and experimentally synthesized two-dimensional transition metal dichalcogenides (TMDs). Huge MAEs in the range of 102.09–247.69 meV were found in 13 of these heterodimensional systems. In particular, the Os-Ru@T-ZrSe2 with the largest MAE of 247.69 meV corresponds to a theoretical blocking temperature (67 K) in terms of a relaxation time of 10 years and a storage density of 281 Tb·inch−2. The underlying mechanism for the significant enhancement of MAE is attributed to the rearrangement of the in-plane molecular orbitals near the Fermi level, which is closed relative to the electron transfer capability between the Os-Ru dimer and the TMD substrates. In addition, we have also constructed a heat map for TMD-supported Os-Ru dimer, showing the degree of correlation between MAEs and feature descriptors. Our work not only suggests an effective way to improve MAE of transition metal dimers but also extracts relatively simple rules for substrate selection.

Elementary cellular automata realized by stateful three-memristor logic operations

Cellular automata (CA) are computational systems that exhibit complex global behavior arising from simple local rules, making them a fascinating candidate for various research areas. However, challenges such as limited flexibility and efficiency on conventional hardware platforms still exist. In this study, we propose a memristor-based circuit for implementing elementary cellular automata (ECA) by extending the stateful three-memristor logic operations derived from material implication (IMP) logic gates. By leveraging the inherent physical properties of memristors, this approach offers simplicity, minimal operational steps, and high flexibility in implementing ECA rules by adjusting the circuit parameters. The mathematical principles governing circuit parameters are analyzed, and the evolution of multiple ECA rules is successfully demonstrated, showcasing the robustness in handling the stochastic nature of memristors. This approach provides a hardware solution for ECA implementation and opens up new research opportunities in the hardware implementation of CA.

Ten simple rules for designing graphical abstracts.

Ten simple rules for designing graphical abstracts.

The role of social attraction and social avoidance in shaping modular networks.

How interactions between individuals contribute to the emergence of complex societies is a major question in behavioural ecology. Nonetheless, little remains known about the type of immediate social structure (i.e. social network) that emerges from relationships that maximize beneficial interactions (e.g. social attraction towards informed individuals) and minimize costly relationships (e.g. social avoidance of infected group mates). We developed an agent-based model where individuals vary in the degree to which individuals signal benefits versus costs to others and, on this basis, choose with whom to interact depending on simple rules of social attraction (e.g. access to the highest benefits) and social avoidance (e.g. avoiding the highest costs). Our main findings demonstrate that the accumulation of individual decisions to avoid interactions with highly costly individuals, but that are to some extent homogeneously beneficial, leads to more modular networks. On the contrary, individuals favouring interactions with highly beneficial individuals, but that are to some extent homogeneously costly, lead to less modular networks. Interestingly, statistical models also indicate that when individuals have multiple potentially beneficial partners to interact with, and no interaction cost exists, this also leads to more modular networks. Yet, the degree of modularity is contingent upon the variability in benefit levels held by individuals. We discuss the emergence of modularity in the systems and their consequences for understanding social trade-offs.

Ten simple rules for using large language models in science, version 1.0.

Ten simple rules for using large language models in science, version 1.0.

One-dimensional photonic crystal with tilted termination and its angular filtering properties for radiative cooling.

Photonic crystals are known for their band-gap structures. Due to their band-gaps, they can act as filters in both temporal and spatial domains. However, in most cases, due to their physical symmetry, their angular responses are symmetrical. Here, a structure based on a 1D photonic crystal is introduced and analyzed, which has an asymmetric angular selectivity. The structure is analyzed using the plane wave expansion method. The properties of the structure are expressed and verified by a commercial full-wave simulator software. Based on the analysis and its results, some simple design rules are derived. By using the extracted rules and some approximations, the potential of the structure to be used in radiative coolers, which are not completely toward the sky, is introduced. It is shown that if the structure is used as windows in buildings, it can save up to tens of watts per square meter in energy consumption for air conditioning. Finally, the whole structure including the radiative cooler is simulated, and the results support the calculations and approximations.

Efficient code-based fully dynamic group signature scheme

Code-based group signature is an important research topic in recent years. Since the pioneering work by Alamélou et al.(WCC 2015), several other schemes have been proposed to provide improvements in security, efficiency and functionality. However, most existing constructions work only in the static setting where the group population is fixed at the setup phase. Only a few schemes address partially dynamic, which can realize only one of users enrollment or revocation.In this work, we provide an efficient code-based fully dynamic group signature (FDGS) scheme, i.e., users have flexibility when joining and leaving the group. Specifically, to upgrade the scheme into a fully dynamic group signature, we first add a dynamic ingredient into the static 2-RNSD Merkle-tree accumulator (ASIACRYPT 2019), then create a simple rule and utilize the Stern-like zero-knowledge protocol to handle users enrollment and revocation efficiently (i.e., without resetting the whole tree). Moreover, our solution is the first exploration of code-based FDGS with constant signature size.

Considerations in Bayesian agent‐based modeling for the analysis of COVID‐19 data

AbstractAgent‐based model (ABM) has been widely used to study infectious disease transmission by simulating behaviors and interactions of autonomous individuals called agents. In the ABM, agent states, for example infected or susceptible, are assigned according to a set of simple rules, and a complex dynamics of disease transmission is described by the collective states of agents over time. Despite the flexibility in real‐world modeling, ABMs have received less attention by statisticians because of the intractable likelihood functions which lead to difficulty in estimating parameters and quantifying uncertainty around model outputs. To overcome this limitation, a Bayesian framework that treats the entire ABM as a Hidden Markov Model has been previously proposed. However, existing approach is limited due to computational inefficiency and unidentifiability of parameters. We extend the ABM approach within Bayesian framework to study infectious disease transmission addressing these limitations. We estimate the hidden states, represented by individual agent's states over time, and the model parameters by applying an improved particle Markov Chain Monte Carlo algorithm, that accounts for computing efficiency. We further evaluate the performance of the approach for parameter recovery and prediction, along with sensitivity to prior assumptions under various simulation conditions. Finally, we apply the proposed approach to the study of COVID‐19 outbreak on Diamond Princess cruise ship. We examine the differences in transmission by key demographic characteristics, while considering two different networks and limited COVID‐19 testing in the cruise.

Ten simple rules for establishing an experimental lab.

Ten simple rules for establishing an experimental lab.

Profitability of technical trading rules in the Chinese stock market

This article examines the profitability of technical analysis on the Shanghai Stock Exchange Composite Index (SSEC) and the Growth Enterprise Market (GEM) Index, employing stepwise generalized error rate control procedures to address the data-snooping bias. Our comprehensive study encompasses 38,456 trading rules, extending beyond prior research by incorporating simple rules alongside their contrarian and complex counterparts. Upon rectifying data-snooping bias, we show that only a few complex rules outperform SSEC in different testing sub-periods, and no trading rules outperform GEM. As the outperforming rules are based on relatively high frequent trades, most lucrative rules yield negative returns in the out-of-sample periods once transaction costs were considered. Our new findings shed light on the efficiency of the Chinese stock market from 2010 to 2021.

Strategic disclosure with reputational concerns

I study a strategic disclosure model wherein an uninformed decision-maker (DM) consults an expert of uncertain types regarding the state before acting. The expert may be an honest type, who is committed to reporting the truth; or a strategic type, whose payoff increases in the DM’s action independent of the state and, thus, strategically discloses information to facilitate his agenda while also valuing a reputation for honesty. We find that if the expert fails to obtain information with positive probability, a monotone equilibrium exists that involves an interval wherein the strategic expert adopts a mixed strategy for disclosure, in contrast to a simple cutoff rule that cannot be sustained in equilibrium. The value that the strategic expert attaches to reputation serves as a commitment device to promote disclosure, as does the higher probability that the state is observed, whereas an honest expert’s greater presence may harm the strategic expert’s disclosure incentive.

Simulating staff activities in healthcare environments: An empirical multi-agent modeling approach

The layout of the healthcare environment profoundly impacts healthcare efficiency, safety, employee satisfaction, and the sustainability of operations, mainly based on occupant behavior analysis. However, due to the increase in professionalism and interprofessional collaboration among healthcare practitioners and the complexity of the physical environment, existing research tools face challenges in describing and analyzing diverse occupant behaviors. This study aims to offer an empirically grounded multi-agent modeling approach as a research tool to simulate and reproduce occupant behavior within healthcare settings. Employing a design science research method, the proposed approach encompasses four stages: empirical data collection, development of behavioral rules, agent-based modeling, and validation. A continuous 24-h observational study involving doctors, nurses, and auxiliary staff within a trauma intensive care unit is conducted to demonstrate the development and application process. Results show that the proposed modeling approach achieves a simulation deviation of 8.31 % in individual walking distances and a 16.26 % deviation in overall staff spatial visitation frequency compared to real-world observations. We believe that using simple if-then rules to represent events and probability rules to describe other basic activities can simulate complex staff activities in a healthcare environment. Interdisciplinary expert evaluation acknowledged the utility of this approach. This study offers a comprehensive dataset of behaviors and contributes methodologically to evaluating the efficiency of built environment layouts. The innovation in this study lies in its scalability, extending from events and individuals to encompass the all staff in levels of modeling and validation, ensuring a consistent alignment with empirical data at each stage.

Evaluation of a Simplified Model for Three-Phase Equilibrium Calculations of Mixed Gas Hydrates

In this study, we perform an extensive evaluation of a simple model for hydrate equilibrium calculations of binary, ternary, and limited quaternary gas hydrate systems that are of practical interest for separation of gas mixtures. We adopt the model developed by Lipenkov and Istomin and analyze its performance at temperature conditions higher than the lower quadruple point. The model of interest calculates the dissociation pressure of mixed gas hydrate systems using a simple combination rule that involves the hydrate dissociation pressures of the pure gases and the gas mixture composition, which is at equilibrium with the aqueous and hydrate phases. Such an approach has been used extensively and successfully in polar science, as well as research related to space science where the temperatures are very low. However, the particular method has not been examined for cases of higher temperatures (i.e., above the melting point of the pure water). Such temperatures are of interest to practical industrial applications. Gases of interest for this study include eleven chemical components that are related to industrial gas-mixture separations. Calculations using the examined methodology, along with the commercial simulator CSMGem, are compared against experimental measurements, and the range of applicability of the method is delineated. Reasonable agreement (particularly at lower hydrate equilibrium pressures) between experiments and calculations is obtained considering the simplicity of the methodology. Depending on the hydrate-forming mixture considered, the percentage of absolute average deviation in predicting the hydrate equilibrium pressure is found to be in the range 3–91%, with the majority of systems having deviations that are less than 30%.

Fast Local Rules Based Switching and Routing Within Multidimensional Torus Interconnect

Multidimensional torus networking topology has become widespread recently in the domain of high-performance computers, clusters, and grids, as well as in the domain of networks on chip. Torus represents an ideal communication structure with the shortest distance and multitude of alternative shortest paths between a pair of nodes. We study simple and powerful local packet forwarding (switching) rules that provide packet delivery with quasi-optimal load balancing and do not use tables of addresses (routes). Implementation of these rules in the form of micro-program code within switching nodes increases considerably network performance, security, and QoS. We use infinite Petri nets and reenterable models in the form of colored Petri nets for prototyping the multi-dimensional torus interconnect simulator to study and compare the packet forwarding rules. Then, an ad-hoc simulator of torus interconnect ts is implemented in the C language to provide high performance and the possibility of simulation over prolonged intervals of time. The simulation results acknowledge the advantages of local packet forwarding rules.

Leading collaborative change amid a crisis: a framework to liberate a team’s leadership skills and promote sales performance

PurposeThis study aims to introduce an alternative model, “volatility, uncertainty, complexity and ambiguity (VUCA), Virtue and Vice” (3V’s), to unleash leadership skills, promote organisational collaborative change and impact sales performance during an unprecedented crisis.Design/methodology/approachThe methodology outlines action research based on the 3V’s model and its application in an international business-to-business sales organisation during Covid-19. It explores alternative paths informed by play-at-work and Plato’s philosophy applied to work-based-learning. Each action/iteration adds to the model, which becomes more likely appropriate for various situations.FindingsThe 3V’s boosted change implementation and improved sales performance. The 3V’s conceptualised an invitation to immerse oneself in the constant “river of change” (VUCA) and a means of understanding the role of leadership in navigating this change by embracing simple rules: searching for justice (Virtue) and overcoming the barrier of public opinion (Vice).Research limitations/implicationsThe 3V’s model is grounded in leadership literature and a sole application, providing real international data relevant to organisations and leaders. This has yet to be evaluated further.Practical implications3V’s can enhance the understanding of a leading collaborative change and re-frame team dynamics in post-pandemic times for the broader public.Social implicationsThe approach advocated is a practice of “swimming alongside the team”, which should enable empowerment and collaboration rather than a top-down direction. Focussing on leaders who are moral people, this approach becomes a differentiator in a digital world.Originality/valueThis study examines Plato’s philosophy, play-at-work and other leadership theories in a model which prepares organisations to respond to crisis by providing the ability to reflect on human aspects and straightforward, transferable skills.

A statistical Markov-based password strength meter

Although multi-factor authentication is gaining popularity, password-based authentication remains the most commonly employed method for both online login and data encryption. To help users choose secure passwords, password strength meters (PSMs) are a well-known and important tool. However, many PSMs still use simple rule sets or rely on heuristic results. With the continuous development of password-cracking methods, it is difficult for such PSMs to provide accurate assessment results. In this paper, we present a new PSM based on statistical results from a huge number of leaked passwords. The proposed method has a very simple structure, requires only a small amount of storage space, and succeeds in providing reliable feedback in real time. We also confirm the influence of linguistic features on user-created passwords and, therefore, recommend evaluating passwords based on the users’ language.

Update on central oculomotor disorders and nystagmus

The diagnosis of ocular motor disorders and the different forms of a nystagmus is based on a systematic clinical examination of all types of eye movements: eye position, spontaneous nystagmus, range of eye movements, smooth pursuit, saccades, gaze-holding function, vergence, optokinetic nystagmus, as well as testing of the function of the vestibulo-ocular reflex (VOR) and visual fixation suppression of the VOR. Relevant anatomical structures are the midbrain, pons, medulla, cerebellum, and cortex. There is a simple clinical rule: vertical and torsional eye movements are generated in the midbrain, horizontal in the pons. The cerebellum is relevant for almost all types of eye movements; typical pathological findings are saccadic smooth pursuit, gaze-evoked nystagmus or dysmetric saccades.Nystagmus is defined as a rhythmic, most often involuntary eye movement. It normally consists of a slow (pathological) drift of the eyes and a fast central compensatory movement of the eyes back to the primary position (re-fixation saccade). There are three major categories: first, spontaneous nystagmus, i. e. nystagmus which occurs in the gaze straight ahead position as upbeat or downbeat nystagmus; second, nystagmus that becomes visible at eccentric gaze only and third, nystagmus which can be elicited by certain maneuvers, e. g. head-shaking, head positioning, air pressure or hyperventilation, most of which are of peripheral vestibular origin. The most frequent central types of spontaneous nystagmus are downbeat and upbeat, infantile, pure torsional, pendular fixation, periodic alternating, and seesaw nystagmus. Many types of central nystagmus allow a precise neuroanatomical localization: for instance, downbeat nystagmus, which is most often caused by a bilateral floccular lesion or dysfunction, or upbeat nystagmus, which is caused by a lesion in the mesencephalon or medulla oblongata. Examples of pharmacotherapy are the use of 4-aminopyridine for downbeat and upbeat nystagmus, memantine or gabapentin for fixation pendular nystagmus or baclofen for periodic alternating nystagmus.

Determining Distinct Suicide Attempts From Recurrent Electronic Health Record Codes: Classification Study.

Prior suicide attempts are a relatively strong risk factor for future suicide attempts. There is growing interest in using longitudinal electronic health record (EHR) data to derive statistical risk prediction models for future suicide attempts and other suicidal behavior outcomes. However, model performance may be inflated by a largely unrecognized form of "data leakage" during model training: diagnostic codes for suicide attempt outcomes may refer to prior attempts that are also included in the model as predictors. We aimed to develop an automated rule for determining when documented suicide attempt diagnostic codes identify distinct suicide attempt events. From a large health care system's EHR, we randomly sampled suicide attempt codes for 300 patients with at least one pair of suicide attempt codes documented at least one but no more than 90 days apart. Supervised chart reviewers assigned the clinical settings (ie, emergency department [ED] versus non-ED), methods of suicide attempt, and intercode interval (number of days). The probability (or positive predictive value) that the second suicide attempt code in a given pair of codes referred to a distinct suicide attempt event from its preceding suicide attempt code was calculated by clinical setting, method, and intercode interval. Of 1015 code pairs reviewed, 835 (82.3%) were nonindependent (ie, the 2 codes referred to the same suicide attempt event). When the second code in a pair was documented in a clinical setting other than the ED, it represented a distinct suicide attempt 3.3% of the time. The more time elapsed between codes, the more likely the second code in a pair referred to a distinct suicide attempt event from its preceding code. Code pairs in which the second suicide attempt code was assigned in an ED at least 5 days after its preceding suicide attempt code had a positive predictive value of 0.90. EHR-based suicide risk prediction models that include International Classification of Diseases codes for prior suicide attempts as a predictor may be highly susceptible to bias due to data leakage in model training. We derived a simple rule to distinguish codes that reflect new, independent suicide attempts: suicide attempt codes documented in an ED setting at least 5 days after a preceding suicide attempt code can be confidently treated as new events in EHR-based suicide risk prediction models. This rule has the potential to minimize upward bias in model performance when prior suicide attempts are included as predictors in EHR-based suicide risk prediction models.

Mineral exploration and regional surface geochemical datasets: An anomaly detection and k-means clustering exercise applied on laterite in Western Australia

A comprehensive geochemical survey was conducted in the western Yilgarn Craton, Western Australia, in 2007, collecting 3142 surface samples of regolith. Our study used this data to target potential sites for undiscovered buried or concealed Cu-Zn-Pb, and NiCu deposits. The core approach used the singularity mapping technique for detecting anomalies at the local scale. This work proposes a procedure to create a composite multi-element singularity map by linearly combining individual element singularity maps, using element-to-element correlation coefficients as weights for the linear combination process. Furthermore, the k-means clustering algorithm was applied to combinations of sub-sets of data and singularity values. Expert validation indicated that the k-means clustering approach yielded the best results when using 4 or 5 clusters, separating the distinct sites of the MINEDEX database. In either case, the incorporation of the singularity values provided the most accurate outcomes, with a dominant cluster correctly classifying up to 60 to 80 % of identified Cu and Ni deposits and mines, respectively.Based on these results and on the range of computed singularity values, simple rules were established to identify sampled data points satisfying the following criteria: (i) meeting the defined threshold singularity value and belonging to the k-means cluster that include the mines and (ii) not being in the neighbourhood of any known mineralization site from the MINEDEX database. These locations thus represent potential mineralization sites that warrant further investigation and exploration follow-up. The outcomes of this study strongly support the efficiency of anomaly detection and k-means clustering method applied on a regional surface geochemical dataset for mineral exploration to detect and target mineral systems.

Study of threshold energy [formula omitted] in EXAFS

This work demonstrates that the threshold energy E0 can be obtained from a simple tentative rule and the bond length R can be obtained correctly by running the FIT program while fixing E0. The extended X-ray absorption fine structure (EXAFS) spectra for Cu, W, and Au metal foils are tested and for the anharmonic system, the experimental Cu spectra measured at temperatures of 50, 150, 295, 400, 500, 600 and 700K. From the tests, it is confirmed that a more precise bond length R comparable to the crystallographic data can be obtained for both cases. Moreover, it is deduced that the new running mode of the conventional EXAFS FIT program yields satisfactory results for the anharmonic system.