Limited Set Of Values Research Articles

Hyperparameters optimization for the machine learning

There is no single best Hyperparameter Optimization algorithm. Different optimization algorithms meet different Hyperparameter Optimization tasks with different constraints. To accelerate the Hyperparameter Optimization, it is necessary to parallelize training executions of various tests, introduce distributed training and prematurely stop unpromising tests. It is recommended to use a library approach to support the hyperparameter optimization service. Ray Tune is the best by far among the open source Hyperparameter Optimization. Hyperparameter optimisation (HPO) is the process of identifying a set of hyperparameters that yields an optimal model. By optimal, we mean the model that minimises a predefined loss function on a given data set. This is a repeated model training process, except that the neural network is trained with a different set of hyperparameters each time. In this process, the optimal set of hyperparameters will be identified. During the grid search, users specify a limited set of values for each hyperparameter and then select trial hyperparameters from the Cartesian product of these values. Once the grid is constructed, the GPGs are tested with the grid values. The grid search suffers when the number of hyperparameters becomes larger or the parameter search space becomes larger, as in this case the required number of estimates will grow exponentially. Another problem with grid search is its inefficiency. Since grid search treats each set of hyperparameter candidates equally, it will spend a lot of computational resources in the suboptimal configuration space without spending enough computational power on the optimal space.

О возможности единых и контрпродуктивности одинаковых критериев оценки риска промышленной аварии

The risk-oriented approach in ensuring industrial safety is intended to orient industrialists, supervisory authorities and the expert community in the existing emergency hazards and threats of today industrial Russia. In recent decades, there is a dangerous trend of opportunistic introduction of universal criteria for safe operation. In fact, instead of a risk-oriented approach, a risk-prescriptive approach is proposed. Any risk assessment methodology is only a means for measuring hazard, and is not at all a guarantor or a witness of compliance with safety. In order to eliminate measurement errors as much as possible, it is required to evaluate not the absolute level of accident hazard, but the relative one. The tools for measuring hazard (accident risk assessment at a hazardous production facility) cannot give a reliable, comprehensive conclusion about the safety of a hazardous production facility. Safety is not a mechanistic absence of hazard, but a systemic property of the technical-social system «source of hazard — those at risk» to function in conditions of changing hazards and threats that arise from them. Hazards are objective, and safety is a cultivated systemic property of hazardous industries to prevent the transformation of hazards into threats. In a risk-oriented approach to industrial safety, it is required to distinguish between information social engineering technology risk management (impact on ideas about hazards and threats) and organizational and technical management of a directly hazardous production facility, controlled by hazard analysis with a reliable assessment of the risk of an accident. The main criterion for ensuring the safe operation of a hazardous production facility should be considered a set of limit values of safe operation parameters and conditions for non-occurrence of emergency threats of major industrial accidents in the performance of existing industrial safety requirements. Criteria for acceptable accident risk must be established in accordance with the industry level of emergency threats. Due to the significant variety of possible causes of accidents, scenarios for their occurrence and development, a wide range of possible consequences of industrial accidents, it is not possible to establish absolutely identical, so-called «unified» criteria for acceptable accident risk for different hazardous production facilities: acceptable accident risk as a measure of acceptable hazard, cannot be accepted as a single criterion for ensuring industrial safety of a hazardous production facility. Unified criteria for assessing the risks of accidents at industrial facilities are not single and individual microscopic probabilities that are not the same for all different industries. Unified criteria are a unified set of methods for developing, establishing, testing and adopting criteria for assessing hazards using risk as a special measure of hazard.

Size correction scheme to determine fracture toughness with mini-CT geometry in the transition regime

The mini-CT geometry is used to determine relevant fracture toughness data along with the master curve description within the transition regime. However, due to significant loss of constraint experienced at loadings close to J-levels corresponding to the reference temperature T0, the current size correction scheme from ASTM E1921 standard requires a better assessment in order to avoid censoring a large number of mini-CT specimens. Indeed, the current tight ASTM E1921 requirements on the KJc limit value set to ensure that the computed transition temperature T0 is reliable often implies that many samples have to be censored. A large number of censored specimens leads to a significant loss of time, money and material, and of unnecessary activated material in the case of irradiated specimens. Besides, because of the specimen size reduction, more mini-CT samples and lower test temperatures as compared to large sized samples are required to determine a reliable T0 value. In this study, an improved specimen size correction associated to the mini-CT geometry is proposed based on a local approach of brittle fracture combined with FEM simulations. The results show that the proposed size correction reduces the T0 bias compared to the 1T-CT geometry. It also contributes to relaxing the KJc limit for the mini-CT geometry as compared to the ASTM size corrected values.

Air Quality Impacts on the Giant Panda Habitat in the Qinling Mountains: Chemical Characteristics and Sources of Elements in PM2.5

The wild giant panda habitat is inaccessible and far away from the main areas of human activity, so environmental pollutants entering the habitat are mainly the result of external migration and spread through the atmospheric advection and diffusion processes and particulate matter deposition. To research the variation, transmission route, chemical characteristics, and source of PM2.5 in the habitat of wild giant pandas, we set up a PM2.5 sampling point near the Shaanxi Foping National Nature Reserve (SFNNR), which is the area with the highest population density of wild giant pandas in the Qinling Mountains. The 12-month average concentration of PM2.5 was 11.3 ± 7.9 μg/m3 from July 2021 to June 2022, and the 12-month average concentration did not exceed the limit value set in the standard. In the results of our analysis of element concentrations, As and Pb were much lower than the limit standard. Si, S, P, and Cl accounted for 99.60% of nonmetallic elements, while the proportion of the six metallic elements, Na, Mg, Al, K, Ca, and Fe, was 96.27%. According to the analysis results of enrichment factor (EF) and pollutant emission sources, there were four sources for the total elements in PM2.5, which were mainly distributed in the areas around the reserve. These included dust, coal combustion, biomass burning, and traffic-related emissions, which contributed 55.10%, 24.78%, 11.91%, and 8.22% of the total element mass in PM2.5, respectively. Additionally, Pb, Cu, Zn, As, Sc, Co, Ga, Mg, and, especially, Se were severely affected by human activities (coal burning, biomass burning, and traffic-related emissions). In the villages and towns around the wild giant panda habitat, the majority of energy for cooking and heating comes from coal and biomass burning, and older vehicles with high emissions are used more frequently. Therefore, to better protect the health of and reduce the impact of environmental pollution on wild giant pandas, we put forward relevant recommendations, including upgrading the energy structure of towns and villages near the habitat to increase the proportion of clean energy, such as photovoltaic power generation, natural gas, etc.; decreasing the combustion of coal and biomass; encouraging the upgrading of agricultural diesel machines and older vehicles used in these areas; and setting limits on vehicle emissions in areas surrounding the habitat.

Public values in the socio-technical construction of autonomous vehicle futures

ABSTRACT This study argues that policymaking guided by public values can help to secure public benefit in technology implementation, for two reasons. Firstly, the emergence and deliberation over plural values can result in more publicly beneficial outcomes; secondly, public values establish the meaningful link between public interest and policy goals. We explore the value bases of arguments around the societal implementation of autonomous vehicles through interviews with professionals. Mapping values on a conceptual model with two dimensions of recognition-neglect and consensus-dissensus, we find that a limited set of values receives recognition, while two distinct sets are contested or neglected almost entirely.

Using artificial intelligence and real galaxy images to constrain parameters in galaxy formation simulations

ABSTRACT Cosmological galaxy formation simulations are still limited by their spatial/mass resolution and cannot model from first principles some of the processes, like star formation, that are key in driving galaxy evolution. As a consequence they still rely on a set of ’effective parameters’ that try to capture the scales and the physical processes that cannot be directly resolved in the simulation. In this study, we show that it is possible to use Machine Learning techniques applied to real and simulated images of galaxies to discriminate between different values of these parameters by making use of the full information content of an astronomical image instead of collapsing it into a limited set of values like size, or stellar/ gas masses. In this work, we apply our method to the NIHAO simulations and the THINGS and VLA-ANGST observations of H i maps in nearby galaxies to test the ability of different values of the star formation density threshold n to reproduce observed H i maps. We show that observations indicate the need for a high value of n ≳ 80 cm−3 (although the numerical value is model-dependent), which has important consequences for the dark matter distribution in galaxies. Our study shows that with innovative methods it is possible to take full advantage of the information content of galaxy images and compare simulations and observations in an interpretable, non-parametric, and quantitative manner.

Six Sigma Analysis as an Approach to Improve Quality of Corrugated Zinc Sheet Product

Every manufacturing company will strive to create the best quality products. This is also done by PT. CMSM, a steel company, is producing corrugated zinc products. In several production periods, the defective product values were still found that exceeded the tolerance limit value set at 0.5% in corrugated zinc products. These problems are, of course, very detrimental to the company, so it’s essential to control the quality of corrugated zinc products. This study aimed to determine the factors that cause product defects, propose plans to improve product quality, and provide managerial recommendations based on Six Sigma analysis. Data collection techniques are carried out through observation, interviews, and documentation. Based on the study results, it is known that DPO is 0.000885 and DPMO is 884.6028. At this time, the company is at the level of 4.64 sigma with CTQ (Critical to Quality) folded zinc sheet, cut size is not according to standard, thickness is not according to standard, uneven coating layer and perforated zinc sheet. Based on the analysis, five factors cause product defects: humans, machines, methods, materials, and the environment. To improve quality, the company should improve their quality control through 5W + 1H analysis, namely by providing training to employees, periodic machine maintenance and ensuring that the SOPs that have been made are implemented correctly and adequately. Keywords: six sigma, DMAIC, product defect, quality control, manufacturing

Algorithm for detecting a change in the motion mode of an object moving along a complex trajectory

The present paper solves the problem of quick detection of a change in the motion mode of an object moving along a complex trajectory. The process of the object movement is described by a hybrid stochastic model. To solve the problem, a sequential probability ratio criterion is applied. A distinctive feature of the proposed algorithm is the ability to make decisions on a limited set of values of the likelihood ratio function. The results of numerical experiments confirm the efficiency of the developed algorithm.

Translation hypothesis specifics and problems of translation of scientific and technical multi component terms

In this article highlights of translation hypothesis. specifics and problems of translation of scientific and technical multicomponent terms. We divide it into two components: the total power and the directed rays. One of the most effective methods for testing a hypothesis is a search engine on the Internet. The dictionary includes only a limited set of values in each zone: not everything that is in the language, but only what may be needed for automatic processing of highly specialized texts and makes this processing less complex. In order to translate them correctly, you need to understand how the keywords are expressed in these terms. We see that all of them have a suffix-n, which most likely indicates that they belong to the verbal forms of the noun.

Model Comparison Metrics Require Adaptive Correction if Parameters Are Discretized: Proof-of-Concept Applied to Transient Signals in Dynamic PET.

Linear parametric neurotransmitter PET (lp-ntPET) is a novel kinetic model that estimates the temporal characteristics of a transient neurotransmitter component in PET data. To preserve computational simplicity in estimation, the parameters of the nonlinear term that describe this transient signal are discretized, and only a limited set of values for each parameter are allowed. Thus, linear estimation can be performed. Linear estimation is implemented using predefined basis functions that incorporate the discretized parameters. The implementation of the model using discretized parameters poses unique challenges for significance testing. Significance testing employs model comparison metrics to determine the significance of the improvement of the fit accomplished by including a basis function, i.e. it determines the presence of a transient signal in the PET data. A false positive occurs when the bases overfit data that do not contain a transient component. The number of parameters in a model, p, is necessary to determine the degrees of freedom in the model. In turn, p is crucial for the calculation of model selection metrics and controlling the false positive rate (FPR). In this work, we first explore the effect of parameter discretization on FPR by fitting simulated null data with varying numbers of bases. We demonstrate the dependence of FPR on number of bases. Then, we propose a correction to the number of parameters in the model, peff , which adapts to the number of bases used. Implementing model selection with peff maintains a stable FPR independent of number of bases.

Genetic Algorithm-Optimized Fuzzy Lyapunov Reinforcement Learning for Nonlinear Systems

This paper aims to introduce nonlinear optimization in the fuzzy reinforcement learning (RL) approach through genetic algorithm (GA)-based minimization. In conventional fuzzy RL, an agent attempts to find most optimal action at each stage by choosing an action having the lowest Q value or the greedy action. However, Q function is an unknown function and an attempt to find minima of such a function based on a limited set of values, in our view, is inaccurate and insufficient. A more rigorous approach would be to employ a nonlinear optimization procedure for finding minima of the Q function. We propose to employ genetic algorithm for finding optimal action value in each iteration of the algorithm rather than plain algebraic minimum. For guaranteed stability of the designed controller, we use Lyapunov theory-based fuzzy RL control with GA optimizer. We validate the performance of our controller on three benchmark nonlinear NL control problems: (1) inverted pendulum swing up, (2) cart pole balance, and (3) rotational/translational proof-mass actuator system. We carry out comparative evaluation of our controller against: (1) hybrid Lyapunov fuzzy RL control and (2) fuzzy Q learning control. Results show that our proposed GA-optimized fuzzy Lyapunov RL controller is able to achieve a high success rate with stable and superior tracking performance.

Determinants of Public Acceptance for Traffic-Reducing Policies to Improve Urban Air Quality

Air pollution remains a problem in German cities. In particular, the nitrogen dioxide (NO2) annual limit-value set by the European Union of 40 µg/m3 was not met at ~40% of roadside monitoring stations across German cities in 2018. In response to this issue, many cities are experimenting with various traffic-reducing measures targeting diesel passenger vehicles so as to reduce emissions of NO2 and improve air quality. Identifying the determinants of public acceptance for these measures using a systematic approach can help inform policy-makers in other German cities. Survey data generated from a questionnaire in Potsdam, Germany, were used in predictive models to quantify support for investments in traffic-reducing measures generally and to quantify support for a specific traffic-reducing measure implemented in Potsdam in 2017. This exploratory analysis found that general support for investments in such measures was most strongly predicted by environmental and air pollution perception variables, whereas specific support for the actual traffic measure was most strongly predicted by mobility habits and preferences. With such measures becoming more common in German cities and across Europe, these results exemplify the complexity of factors influencing public acceptance of traffic-reducing policies, highlight the contrasting roles environmental beliefs and mobility habits play in determining support for such measures, and emphasize the connections between mobility, air pollution, and human health.

Intermediate transverse stiffener requirements of high-strength steel plate girders considering postbuckling capacity

The postbuckling capacity of HSS plate girders is larger than that of mild steel plate girders because of the differences in material properties. Hence, to fully develop the postbuckling capacity, the intermediate transverse stiffener requirement of HSS plate girders could be different from that of mild steel plate girders. The plate girders concerned in this study are without a longitudinal stiffener. To investigate the aforementioned issue, the minimum moment of inertia requirements of intermediate transverse stiffeners in HSS and mild steel plate girders are studied through the finite element analysis (FEA). After the comparison between the FEA results and the results from the design equations in AASHTO LRFD, it states that the design equations in AASHTO LRFD could not be directly used in the design of intermediate transverse stiffeners in HSS plate girders. Hence, based on the FEA results, a new equation is proposed to predict the minimum moment of inertia requirement of intermediate transverse stiffeners in HSS plate girders. Furthermore, because of the difference in the resistant capacity between HSS and mild steel plate girders, the maximum additional out-of-plane deflection of the intermediate transverse stiffener in HSS plate girders corresponding to the ultimate shear resistance is significantly larger than that of the intermediate transverse stiffener in mild steel plate girders. Hence, there is a noteworthy adverse effect caused by the additional out-of-plane deflection of the intermediate transverse stiffener on the shear resistance of HSS plate girders with the maximum limit value set.

Criticality of the reaction zone 9 of Oklo reactors revisited

New conditions on the occurrence of the criticality in Reaction Zone 9 (RZ9) of Oklo natural reactors (Gabon) are reported. Analytical expressions relating the effective neutron multiplication factor and the most influential parameters with respect to the fission chain reaction behaviour have been derived for two configurations of the reaction zone using the two-group diffusion theory. The dependence of the effective neutron multiplication factor on the thickness, the radius, the porosity and the uranium content of the reaction zone was investigated by means of the design of experiments method in order to establish a new set of limit values corresponding to critical configurations.The developed method is validated through the verification of the criticality occurrence with the new set of parameters of a reaction zone model close to the real RZ9 configuration using the analytical calculations of the effective neutron multiplication factor and simulation results of the continuous energy Monte Carlo code MCNP6.

Spatio-temporal Variations in Water Quality Parameter Trends in River Waters

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.

Comparative Study Regarding Atmospheric SO2 Content in Rovinari and Turceni Areas

The goal of this research study is to compare the air quality of two urban locations from Targu-Jiu County namely Rovinari and Turceni. Measurements of SO2 content with automatic analysers were used as a criterion to asssess the air quality. Rovinari and Turceni areas were chosen for this study due to the fact that there are located two thermal power plants considered high stationary sources with an important contribution to regional and global pollution by sulfur dioxide, nitrogen oxides and dust. Sustainable development of fossil fuel power plants cannot be done without the use of technology to limit or eliminate environmental pollution. Studies regarding determination of SO2 content in the monitored areas were performed from January to December 2014. By interpreting the results obtained it can be concluded that the concentrations of sulfur dioxide in the ambient air are below the limit value set in legislation. This is mainly due to the developing of the programs for the progressive reduction of annual emissions of sulfur dioxide, nitrogen oxides and dust which was set up by operators of thermal power plants in order to comply with emission limit values. The high level of SO2 concentration in cold season is attributed to intensifying the burning of fossil fuels for household activities.

A Worpitzky boundary theorem for branched continued fractions of the special form

For a branched continued fraction of a special form we propose the limit value set for the Worpitzky-like theorem when the element set of the branched continued fraction is replaced by its boundary.

Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments

The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure–response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure–response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure–response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure–response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N=321) conducted for the construction of an urban LRT in the United Kingdom.

Indoor/outdoor PM2.5 elemental composition and organic fraction medications, in a Greek hospital

In the newly constructed General Hospital of Kavala, Greece, air quality was monitored in two indoor locations (the Triage room at the emergency department and the Laboratory of bio-pathology) and also outdoors. Indoor PM2.5 filter samples were collected at both rooms and outdoors, in the yard of the hospital. PM2.5 organic content and elemental composition were determined. Analyses of selected organic compounds in PM2.5 samples, revealed that chemicals from medications were distributed in the air of the hospital. Qualitatively, dehydrocholic acid, hydrocortisone acetate, gama-bufotalin, syrosingopine, dimethyl phthalate and o,p′-DDT were found in the Triage. In the bio-pathology laboratory, triethoxypentylsilane and carbohydrazide were also found. An unexpected air pollutant pathway was the pneumatic system which delivered the blood samples from the emergency department to the bio-pathology laboratory, as the presence of gama-bufotalin and syrosingopine was found in the aerosol samples from both locations. Indoor PM2.5 24-h average mass concentration ranged from 10.16μgm−3 to 21.87μgm−3 in the laboratory and between 9.86μgm−3 to 26.27μgm−3 in the Triage room, where the limit value set for human health protection, i.e. 25μgm−3 for 24h, was exceeded once. The I/O 24-h average PM2.5 mass concentration ratio, ranged from 0.74–1.11 in the Triage and from 0.67–1.07 in the Lab, respectively. On the contrary, the I/O elemental concentration ratios were below unity for the whole campaign, indicating an outdoor origin of the monitored elements (Al, Si, Br, P, S, Na, K, Mg, Ca, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti and Zn). This finding was also confirmed by high sulfur I/O ratios in both rooms. The diurnal variations of PM2.5, Black Carbon, CO2 concentrations and microclimatic conditions were also monitored.

The Evaluation Of The Concentration Of Chlorides And Sulphates In Surface Water Of The National Nature Reserve Čičov Oxbow

Abstract In the years 2013–2014 we evaluated changes in concentrations of chlorides and sulphates in waters of the National Nature Reserve Čičov oxbow depending on the time and place of sampling. Collections of samples were realized regularly at monthly intervals, always in the half of a month. Sampling sites were determined in order to assess the impact of natural and anthropogenic source of surface water quality. In order to evaluate the quality of surface water in the sampling sites by individual indicators, we used the values of the 90th percentile (P90), which was calculated from the measured values and then compared with their matching set of limit values referred to the Regulation of the Government of the Slovak Republic No. 269/2010 Coll. According to that Regulation, the recommended value for chlorides is 200 mg dm;; and for sulphates 250 mg dm−3. Based on the calculated values of 90th percentile (P90) of these indicators, we found out that the calculated characteristic values are lower.