Random Draws Research Articles

A Survey of Learning Criteria Going beyond the Usual Risk (Abstract Reprint)

Virtually all machine learning tasks are characterized using some form of loss function, and "good performance" is typically stated in terms of a sufficiently small average loss, taken over the random draw of test data. While optimizing for performance on average is intuitive, convenient to analyze in theory, and easy to implement in practice, such a choice brings about trade-offs. In this work, we survey and introduce a wide variety of non-traditional criteria used to design and evaluate machine learning algorithms, place the classical paradigm within the proper historical context, and propose a view of learning problems which emphasizes the question of "what makes for a desirable loss distribution?" in place of tacit use of the expected loss.

Resource allocation, computational complexity, and market design

With three experiments, we study the design of financial markets to help spread knowledge about solutions to the 0-1 Knapsack Problem (KP), a combinatorial resource allocation problem. To solve the KP, substantial cognitive effort is required; random sampling is ineffective and humans rarely resort to it. The theory of computational complexity motivates our experiment designs. Complete markets generate noisy prices and knowledge spreads poorly. Instead, one carefully chosen security per problem instance causes accurate pricing and effective knowledge dissemination. This contrasts with information aggregation experiments. There, values depend on solutions to probabilistic problems, which can be solved by random drawing.

Opportunities for territorial development in the transisthmic corridor; baseline diagnosis in the region of the Isthmus of Tehuantepec, Oaxaca

Objective: The main objective was to know the current situation of livestock production, problems and potentialities, in the municipalities of Matías Romero, Santa María Petapa and San Juan Guichicovi, Oaxaca, located in the transoceanic corridor of the Isthmus of Tehuantepec. Design/methodology/approach: The diagnosis was made in eight communities in the municipalities of Matías Romero, Santa María Petapa and San Juan Guichicovi, located north of the Isthmus of Tehuantepec region, Oaxaca. To determine the sample size, the formula suggested by (Snedecor and Cochran, 1967 and Rojas, 1979) was used. It indicates that the elements must be selected through a random draw with replacement, to define the population, the list of production units registered in the Ministry of Agriculture and Rural Development, whose universe is 215, from which, a sample of 41 units was taken. Results: 36% of the interviewees indicated that the ownership of their land is ejidal, 34% is communal and 30% is small property. The interviewed livestock producers develop their livestock activities on an average of 37 hectares. The production units with the smallest area are 8.5 hectares and those with the largest area are 140 hectares. Of the total number of interviewees, 78% provide themselves with water for cattle in the pasture or corrals, coming from rivers and streams, other sources are springs with 12% and dams with 10%. It is considered that the characteristics described provide adequate conditions for livestock. A problem that afflicts livestock in the tropics in the presence of Ixodoida spp, in addition to other types of Mites, the options and alternatives to combat the tick in the PRODETER territory are through the bathroom, regularly it is done by using spray backpack, also the use of Pour on (loin) and tick-killing baths. The misuse of tick control products has generated resistance and problems for farmers (Piña et al., 2017). More than half of the farmers do not participate in animal health campaigns, only 36% do participate. The animal health campaigns in which farmers participate in PRODETER are bovine tuberculosis and paralytic rabies, 24% respectively, tick control 20% and finally brucellosis with 16%. Leos-Rodríguez, (2008) in the work of economic and productive characterization of bovine cattle producers that make up the list of PROGAN beneficiaries in Mexico, observed that the percentage of producers that participated in campaigns against ticks, tuberculosis and brucellosis is above 91%. What is superior to what was found in this diagnosis. Limitations on study/implications: One of the main limitations was that the PRODETER Program was financed by the State for one year only and with that, in the first instance, it limited the intervention to see the effects and levels of adoption of the technological model in the Family Production Units Findings/conclusions: There is ignorance in the use of food supplements, so the development of calves, and the milk production and fertility of the cows, do not express the potential due to the lack of the necessary nutrients in the different productive stages. There is little use of the rangelands because the farmers ignore the practices to give maintenance, make divisions in the paddocks, so they do not rotate. Among the problems detected, the following stand out, among others: the lack of training, the lack of availability of technicians or experts to attend them, the cost of artificial insemination technology and the long periods between births, which causes calf production to decrease. Therefore, the lack of training in artificial insemination, stallion evaluation and crossbreeding systems for genetic improvement, limit the development of livestock with better quality standards in the region of the Isthmus of Tehuantepec, Oaxaca. The diagnosis as such provides elements for the territorial development of livestock in the transoceanic corridor, since it offers areas of opportunity throughout the production process and can satisfactorily help livestock in that region

THE EFFECT OF MONOPOLY GAMES TOWARD STUDENTS’ VOCABULARY MASTERY

         The research addressed the problem of inadequate vocabulary mastery among seventh-grade students at SMPN 2 Paninjauan during the 2022/2023 academic year. The monotonous media such as using a dictionary was attributed to factors such as rote memorization and the lack of diverse instructional media. Therefore, monopoly games were selected as a teaching medium to investigate their impact on students' vocabulary mastery. The research employed a quasi-experimental design, and the population comprised 45 seventh-grade students at SMPN 2 Paninjauan for the 2022/2023 academic year. Cluster random sampling was utilized to select a sample of 30 students, with 15 assigned to the experimental group and 15 to the control group. The experimental and control groups were determined through a random draw. The pre-test score averaged 47.33, but it significantly increased to 85 after the intervention. Analysis using an independent samples T-test indicated that monopoly games had a more substantial impact compared to dictionary. The rejection of the null hypothesis (H0) suggested a significant positive effect of using monopoly games as a teaching medium on students' vocabulary mastery in the seventh grade at SMPN 2 Paninjauan for the 2022/2023 academic year. Based on the findings, it is recommended that teachers consider this research when exploring a broader range of teaching media to enhance student engagement in vocabulary learning.

THE EFFECT OF POP-UP BOOKS TOWARD STUDENTS’ VOCABULARY MASTERY

        The research addressed the issue of insufficient vocabulary mastery among eighth-grade students at SMPN 1 Kubung during the 2022/2023 academic year. The students' limited proficiency in vocabulary was attributed to factors such as rote memorization and the lack of diverse instructional media. Consequently, pop-up books were selected as a teaching medium to investigate their impact on students' vocabulary mastery. The research employed a quasi-experimental design, and the population comprised 94 eighth-grade students at SMPN 1 Kubung for the 2022/2023 academic year. Cluster random sampling was utilized to select a sample of 63 students, with 31 assigned to the experimental group and 32 to the control group. The experimental and control groups were determined through a random draw. The pre-test score averaged 32.68, but it significantly increased to 70.41 after the intervention. Analysis using an independent samples T-test indicated that pop-up books had a more substantial impact compared to traditional pictures. The rejection of the null hypothesis (H0) suggested a significant positive effect of using pop-up books as a teaching medium on students' vocabulary mastery in the eighth grade at SMPN 1 Kubung for the 2022/2023 academic year. Based on the findings, it is recommended that teachers consider this research when exploring a broader range of teaching media to enhance student engagement in vocabulary learning. Furthermore, future researchers are encouraged to explore additional avenues for improvement and refinement based on the insights gained from this study.

Simulating animal space use from fitted integrated Step‐Selection Functions (iSSF)

Abstract A standing challenge in the study of animal movement ecology is the capacity to predict where and when an individual animal might occur on the landscape, the so‐called, utilisation distribution (UD). Under certain assumptions, the steady‐state UD can be predicted from a fitted exponential habitat selection function. However, these assumptions are rarely met. Furthermore, there are many applications that require the estimation of transient dynamics rather than steady‐state UDs (e.g. when modelling migration or dispersal). Thus, there is a clear need for computational tools capable of predicting UDs based on observed animal movement data. Integrated Step‐Selection Analyses (iSSAs), which integrates movement of the animal into habitat selection analyses, are widely used to study habitat selection and movement of wild animals, and result in a fully parametrised individual‐based model of animal movement, which we refer to as an integrated Step Selection Function (iSSF). An iSSF can be used to generate stochastic animal paths based on random draws from a series of Markovian redistribution kernels, each consisting of a selection‐free, but possibly habitat‐influenced, movement kernel and a movement‐free selection function. The UD can be approximated by a sufficiently large set of such stochastic paths. Here, we present a set of functions in R to facilitate the simulation of animal space use from fitted iSSFs. Our goal is to provide a general purpose simulator that is easy to use and is part of an existing workflow for iSSAs (within the amt R package). We demonstrate through a series of applications how the simulator can be used to address a variety of questions in applied movement ecology. By providing functions in amt and coded examples, we hope to encourage ecologists using iSSFs to explore their predictions and model goodness‐of‐fit using simulations, and to further explore mechanistic approaches to modelling landscape connectivity.

Analysis of the Short-Term Curative Effect of Roxadustat in Treating Renal Anemia in Patients with Peritoneal Dialysis

Objective: To analyze the short-term curative effect of roxadustat in the treatment of renal anemia in patients with peritoneal dialysis. Methods: 70 patients with peritoneal dialysis renal anemia admitted to the dialysis department of our hospital from March 2021–March 2023 were selected as research objects, divided into a research group and a reference group according to random number drawing method, with each group consisting of 35 cases. The patients in the research group were treated with roxadustat, and those in the reference group were treated with recombinant human erythropoietin. The total efficacy, anemia index, iron metabolism index, and occurrence of adverse reactions were compared between the two groups. Results: The total efficacy of the treatment received in the research group was significantly higher than that in the reference group (P < 0.05). In terms of anemia indicators, there was no statistically significant difference between the hemoglobin (Hb), the red blood cell (RBC), and the hematocrit (HCT) of both groups (P > 0.05) before treatment. After treatment, the anemia indicators of the patients in the research group were significantly better than those in the reference group, (P < 0.05). In terms of iron metabolism, before treatment, there was no significant difference between the total iron-binding capacity (TIBC), the transferrin (TRF), the ferritin (FER), and iron (Fe) of both groups (P > 0.05). After treatment, the research group’s iron metabolism indicators were significantly better than those of the reference group (P < 0.05). The incidence of adverse reactions in the research group was significantly lower than that in the reference group (P < 0.05). Conclusion: The short-term curative effect of roxadustat in the treatment of peritoneal dialysis patients was demonstrated through this study, making it a viable treatment option.

Комбінаторний аналіз лотерей

Lottery is by far the oldest and the most widely known game of chance, having been practiced since antiquity. In its various forms, the lottery preserves a basic structure and technical procedure that makes it the easiest and most popular game of chance: the random draw from an urn of some objects (balls, tickets, lots, plates, slips, etc.) containing predefined symbols (numbers, images, words, etc.), followed by the distribution of prizes for players who made correct predictions regarding this draw, according to some pre-established rules. Nowadays, the most prevalent form of lottery is that with randomly selected numbers; winning categories are based on the number of numbers correctly predicted on the playing ticket. The most popular forms of these games are the national and state lotteries. But the most important element contributing to the public's fascination with lottery games is the amount of the prizes, especially for the highest winning category. The possibility (physically real, mathematically too improbable) of getting «the big hit» – winning the big prize – provides a motivation with complex psychological roots that often overlooks the practical aspects, such as the investments in lottery tickets and the mathematical aspects of the game, especially the winning probabilities. It has been proven mathematically that in ideal conditions of randomness, no long-term regular winning is possible for players of games of chance; therefore, gambling is not a good way to make a living. Most gamblers accept this premise, but still work on strategies in hopes of multiple wins over the long run.

Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H

The search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such planets have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since the expected signal strength of atmospheric features is similar to the single-transit performance of JWST, multiple observations are required to confirm any detection. Here, we present two transit observations of the rocky planet GJ 1132 b with JWST NIRSpec G395H, covering 2.8–5.2 μm. Previous Hubble Space Telescope WFC3 observations of GJ 1132 b were inconclusive, with evidence reported for either an atmosphere or a featureless spectrum based on analyses of the same data set. Our JWST data exhibit substantial differences between the two visits. One transit is consistent with either an H2O-dominated atmosphere containing ∼1% CH4 and trace N2O () or stellar contamination from unocculted starspots (). However, the second transit is consistent with a featureless spectrum. Neither visit is consistent with a previous report of HCN. Atmospheric variability is unlikely to explain the scale of the observed differences between the visits. Similarly, our out-of-transit stellar spectra show no evidence of changing stellar inhomogeneity between the two visits—observed 8 days apart, only 6.5% of the stellar rotation rate. We further find no evidence of differing instrumental systematic effects between visits. The most plausible explanation is an unlucky random noise draw leading to two significantly discrepant transmission spectra. Our results highlight the importance of multivisit repeatability with JWST prior to claiming atmospheric detections for these small, enigmatic planets.

A Survey of Learning Criteria Going Beyond the Usual Risk

Virtually all machine learning tasks are characterized using some form of loss function, and “good performance” is typically stated in terms of a sufficiently small average loss, taken over the random draw of test data. While optimizing for performance on average is intuitive, convenient to analyze in theory, and easy to implement in practice, such a choice brings about trade-offs. In this work, we survey and introduce a wide variety of non-traditional criteria used to design and evaluate machine learning algorithms, place the classical paradigm within the proper historical context, and propose a view of learning problems which emphasizes the question of “what makes for a desirable loss distribution?” in place of tacit use of the expected loss.

Probing the Galactic halo with RR Lyrae stars – V. Chemistry, kinematics, and dynamically tagged groups

ABSTRACT We employ a sample of 135 873 RR Lyrae stars (RRLs) with precise photometric-metallicity and distance estimates from the newly calibrated P–ϕ31–R21–[Fe/H] and Gaia G band P–R21–[Fe/H] absolute magnitude–metallicity relations of Li et al., combined with available proper motions from Gaia EDR3, and 6955 systemic radial velocities from Gaia DR3 and other sources, in order to explore the chemistry and kinematics of the halo of the Milky Way (MW). This sample is ideally suited for characterization of the inner- and outer-halo populations of the stellar halo, free from the bias associated with spectroscopically selected probes, and for estimation of their relative contributions as a function of Galactocentric distance. The results of a Gaussian mixture model analysis of these contributions are broadly consistent with other observational studies of the halo, and with expectations from recent MW simulation studies. We apply the hdbscan clustering method to the specific energies and cylindrical actions (E, Jr, Jϕ, Jz), identifying 97 dynamically tagged groups (DTGs) of RRLs, and explore their associations with recognized substructures of the MW. The precise photometric-distance determinations (relative distance errors on the order of 5 per cent or better), and the resulting high-quality determination of dynamical parameters, yield highly statistically significant (low) dispersions of [Fe/H] for the stellar members of the DTGs compared to random draws from the full sample, indicating that they share common star-formation and chemical histories, influenced by their birth environments.

Event-level positive and negative reinforcement risk factors for alcohol use: Moderation by individual-level alcohol consequences and post-traumatic stress disorder symptom severity.

The multistage model of drug addiction posits that risk processes contributing to alcohol use change as individuals develop alcohol use disorders. However, few studies have tested this theory outside of the lab or at the event level. We assessed whether event-level associations between positive reinforcement (e.g., positive affect, sociability expectancies) and negative reinforcement risk factors (e.g., negative affect, tension reduction expectancies) and same-/next-day alcohol consumption varied as a function of an individual's level of alcohol consequences. Given elevated alcohol use consequences among individuals with post-traumatic stress disorder (PTSD) and disruptions in reward processing that affect this population, we also tested whether these processes differed based on the presence and severity of PTSD. We used data from a 30-day ecological momentary assessment study with 174 undergraduate women who regularly engaged in heavy episodic drinking. A majority (78%) of the sample had experienced sexual assault and 44% had current PTSD. Analyses used Bayesian multilevel structural equation modeling with diffuse (non-informative) priors. We used markov chain monte carlo (MCMC) algorithms to generate a series of 10,000 random draws from the multivariate posterior distribution of our sample for each model. Results partially supported the multistage model. Event-level negative reinforcement risk factors only predicted more alcohol consumption among individuals who experienced more alcohol consequences. Findings for positive reinforcement risk factors were partially consistent with hypotheses. Overall, findings appear to operate similarly across PTSD symptom severity. Results suggest that interventions for heavy episodic drinking could benefit from attending to an individual's level of alcohol consequences. For example, preventive interventions for individuals who tend to experience few consequences may benefit more from addressing positive reinforcement risk factors, while treatment interventions for those who experience more consequences may benefit from attending to both positive and negative reinforcement.

Constrained contests with a continuum of battles

We study a contest problem in which two players compete on a continuum of battlefields by spending resources subject to some constraints on their strategies. Following Myerson (1993), we assume that each player's resource allocation on each battlefield is an independent random draw from the same distribution. Within each battlefield, the player who allocates a higher level of resources wins, but both players incur costs for resource allocation. To analyze this problem, we introduce a systematic way to identify equilibrium allocation strategies and show that any equilibrium strategy of a player renders the rival indifferent in terms of the “constraint-adjusted payoff”. Using this, we provide a complete characterization of equilibrium allocation strategies. We also show that whereas a symmetric budget constraint may induce players to spend more resources than in the case with no constraint, asymmetric budgets that are proportional to players' values of winning would eliminate this possibility.

Irresolute choice behavior

AbstractThis paper proposes a model of irresolute choice rationalizing random choice behavior and examines its applications to decision making under certainty, uncertainty, and risk. Depending on the context, the representations feature canonical signal spaces. Decisions are governed by random draws of signals generating stochastic choice functions. Application to portfolio selection and experimental testing are discussed.

Clinical study of Edaravone Dexborneol combined with Tirofiban in treatment of Acute Cerebral Infarction.

To explore the clinical efficacy and safety of edaravone dexborneol combined with tirofiban in the treatment of acute cerebral infarction. This is a retrospective study. A total of 80 patients with acute cerebral infarction (ACI) treated in Cangzhou People's Hospital from March 2018 to December 2021 were selected, and randomly divided into the routine group(n=40) and intervention group(n=40) according to the principle of random draw. Neurological deficits in the two groups were evaluated and compared before and after treatment using the National Institutes of Health Stroke Scale (NIHSS). The quality of life of the patients was evaluated by the modified Rankin Scale (mRS). Before treatment, NIHSS and mRS scores of the two groups were not statistically significant(p>0.05); the levels of Vmin and Qmin in the two groups showed no statistical significance(p>0.05); no statistical significance was found in CRP or IL-6 levels between the two groups(p>0.05). After treatment for 14 days, the NIHSS and mRS scores of the two groups both decreased, which was more significant in the intervention group(p<0.05); Vmin and Qmin levels increased in both groups, which was more obvious in the intervention group(p<0.05); CRP and IL-6 levels reduced in both groups, which was more remarkable in the intervention group(p<0.05). The incidences of relevant adverse drug reactions presented no differences between the two groups during treatment(p>0.05). Edaravone dexborneol combined with tirofiban in the treatment of ACI can effectively improve patients' neurological deficits, quality of life and cerebral blood flow, and reduce inflammatory factor levels, have significant clinical efficacy and high clinical treatment safety.

A Domain-theoretic Approach to Statistical Programming Languages

We give a domain-theoretic semantics to a statistical programming language, using the plain old category of dcpos, in contrast to some more sophisticated recent proposals. Remarkably, our monad of minimal valuations is commutative, which allows for program transformations that permute the order of independent random draws, as one would expect. A similar property is not known for Jones and Plotkin’s monad of continuous valuations. Instead of working with true real numbers, we work with exact real arithmetic, providing a bridge towards possible implementations (implementations by themselves are not addressed here). Rather remarkably, we show that restricting ourselves to minimal valuations does not restrict us much: All measures on the real line can be modeled by minimal valuations on the domain I ℝ ⊥ of exact real arithmetic. We give three operational semantics for our language, and we show that they are all adequate with respect to the denotational semantics. We also explore quite a few examples to demonstrate that our semantics computes exactly as one would expect and to debunk the myth that a semantics based on continuous maps would not be expressive enough to encode measures with non-compact support using only measures with compact support, or to encode measures via non-continuous density functions, for instance. Our examples also include some useful, non-trivial cases of distributions on higher-order objects.

A full characterization of invariant embeddability of unimodular planar graphs

AbstractWhen can a unimodular random planar graph be drawn in the Euclidean or the hyperbolic plane in a way that the distribution of the random drawing is isometry‐invariant? This question was answered for one‐ended unimodular graphs in Benjamini and Timar, using the fact that such graphs automatically have locally finite (simply connected) drawings into the plane. For the case of graphs with multiple ends the question was left open. We revisit Halin's graph theoretic characterization of graphs that have a locally finite embedding into the plane. Then we prove that such unimodular random graphs do have a locally finite invariant embedding into the Euclidean or the hyperbolic plane, depending on whether the graph is amenable or not.

Efficient measurement of spoken English skills: Design and validation of a 6-minute assessment

Efficient measurement of spoken language skills can improve educational and commercial services. Traditional spoken language assessments often require 30–90 minutes. We report the development and validation of a prototype mobile-browser test of spoken English, “APro”, that participants complete in 6–8 minutes. The APro test presents a stratified random draw of 20 interactive tasks (from pool of 377) to participants whose spoken responses are automatically scored, scaled, and reported. APro aggregates skill-specific measures from disparate task types such as open descriptions and story retellings. Each skill-specific score was independently validated, then combined into an overall spoken English score. APro scoring was trained on 30,000 responses from 354 non-native pilot-test participants who connected remotely from their nine home countries on five continents. The final APro instrument was validated on an independent sample of 79 participants resident in seven countries. In the validation set, human and machine scoring of same-test APro administrations correlated r = 0.98, suggesting accurate speech processing. APro scores predicted much of the score variance in traditional concurrent assessments from Oxford, r = 0.86, and Pearson, r = 0.92. Finally, we present detailed results on two new interactive tasks and share changes to the content, procedure, and scoring that yield improved accuracy at shorter duration. [Work supported in part by Google LLC.]

Poster Session: Quantifying Visual Snow Symptoms with a Matching Task.

The primary symptom of Visual Snow Syndrome (VSS) is a veil of dots/static flickering across the entire visual field. VSS is a serious but poorly understood disorder (prevalence 1.4-3.3%). Symptoms of VSS can interfere with daily tasks like driving and reading. However, few studies have examined VSS, and quantitative measurements of symptoms are lacking. We developed a matching task in which participants with VSS adjusted parameters of simulated visual snow on a computer screen; participants modified the contrast, density, speed, and size of an array of dots to match their visual snow. Simulated snow was generated by random independent draws from a binary distribution controlled by the contrast parameter. Snow density was adjusted by setting a proportion of pixels equal to the background luminance. The speed setting determined the lifetime of each snow element, after which it was replaced. Dot size was adjusted by moving closer or further from the display and recording the viewing distance, as perceived snow elements were generally smaller than one pixel viewed from 0.5 m. Individuals with VSS said the simulated snow closely resembled their perceived snow, and parameter settings were consistent across trials. Simulated snow contrast settings were relatively low and dot size was relatively small. This task provides a quantitative assessment of visual snow percepts, which may facilitate assessment of treatments/therapies and testing of hypotheses about underlying mechanisms.

On the reconstruction of functions from values at subsampled quadrature points

This paper is concerned with function reconstruction from samples. The sampling points used in several approaches are (1) structured points connected with fast algorithms or (2) unstructured points coming from, e.g., an initial random draw to achieve an improved information complexity. We connect both approaches and propose a subsampling of structured points in an offline step. In particular, we start with quasi-Monte Carlo (QMC) points with inherent structure and stable L 2 L_2 reconstruction properties. The subsampling procedure consists of a computationally inexpensive random step followed by a deterministic procedure to further reduce the number of points while keeping its information. In these points functions (belonging to a reproducing kernel Hilbert space of bounded functions) will be sampled and reconstructed from whilst achieving state of the art error decay. Our method is dimension-independent and is applicable as soon as we know some initial quadrature points. We apply our general findings on the d d -dimensional torus to subsample rank-1 lattices, where it is known that full rank-1 lattices lose half the optimal order of convergence (expressed in terms of the size of the lattice). In contrast to that, our subsampled version regains the optimal rate since many of the lattice points are not needed. Moreover, we utilize fast and memory efficient Fourier algorithms in order to compute the approximation. Numerical experiments in several dimensions support our findings.