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Found 6674 publications

Introducing the EPP house (topological space) method to solve MRP problems

Laszlo Vasa Balázs Gyenge László Kasza

Publication Name: Plos One

Publication Date: 2021-06-01

Volume: 16

Issue: 6 June

Page Range: Unknown

Description:

The problem of product and process planning analysed so far is how we can take advantage of our strategy in planning. Among the principles of manufacturing and service management concepts is that after planning demand, planning transformation is one of the key steps of integrated efficiency; it makes it possible to save costs that are not value adding and are not necessary from the customer's point of view. Currently, the methods of material requirements and capacity planning can be seen as classic solutions that are based on dependency relations between different resources, which can be dynamic in space and time. Measuring and recording capacities raise several problems in addition to the fact that our planning methods are not always satisfying. In the literature, the methods of material requirements planning or manufacturing resource planning (MRP) are not typically optimization methods, so they do not guarantee the best solution, and even if our planning methods were satisfying, several manufacturing restrictions (the time allowed, the complexity of the planning process, the lack of testing opportunities, etc.) could prevent us from reaching satisfying application. It is necessary to create a simple planning algorithm that can give the planner a greater degree of freedom and that would be simple and algorithmic in order to maintain continuous conscious control, putting an end to planning uncertainty and leading us to the best solution under the given conditions. The aim of our research is to introduce a novel, simple planning algorithm, similar to heuristic methods that eliminates the problem of defining the order quantity when applying traditional methods, which prevents us from determining in advance which method is desirable (causing unnecessary planning steps); computer- based solutions hide the causal relations of the methodology from the planner (causing unreliability uncertainty).

Open Access: Yes

DOI: 10.1371/journal.pone.0253330

Fuzzy flip-flops and neural nets?

Rita Lovassy László T. Kóczy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

J-K flip-flops are elementary digital units providing sequential features/memory functions. Their definitive equation is used both in the minimal disjunctive and conjunctive forms. Fuzzy connectives do not satisfy all Boolean axioms, thus the fuzzy equivalents of these equations result in two non-equivalent definitions, "reset and set type" fuzzy flip-flops (F3) by Hirota & al. when introducing the concept of F 3. The paper gives an overview of some of the most famous F 3-s by presenting their definitions and graphs. An interesting aspect of F3-s might be that they have a certain convergent behavior when one of their inputs (e.g. J) is exited repeatedly. This is true even if the other input (K) is kept at a constant value. The behavior is more versatile if both inputs are given a series of changing values. If J is considered the equivalent of the traditional input of a neuron (with an adder unit applied before J), K might play a secondary modifier's role, or can just be set fix. The paper encourages to the investigation of such possible F3-networks as new alternative types of neural networks. © 2007 IEEE.

Open Access: Yes

DOI: 10.1109/FUZZY.2007.4295435

Biomechanical Investigation of Lower Limbs during Slope Transformation Running with Different Longitudinal Bending Stiffness Shoes

Yaodong Gu Wenjing Quan Hairong Chen Lidong Gao Jialu Huang Jingyi Ye Qian Liu Runhan Lu

Publication Name: Sensors

Publication Date: 2024-06-01

Volume: 24

Issue: 12

Page Range: Unknown

Description:

Background: During city running or marathon races, shifts in level ground and up-and-down slopes are regularly encountered, resulting in changes in lower limb biomechanics. The longitudinal bending stiffness of the running shoe affects the running performance. Purpose: This research aimed to investigate the biomechanical changes in the lower limbs when transitioning from level ground to an uphill slope under different longitudinal bending stiffness (LBS) levels in running shoes. Methods: Fifteen male amateur runners were recruited and tested while wearing three different LBS running shoes. The participants were asked to pass the force platform with their right foot at a speed of 3.3 m/s ± 0.2. Kinematics data and GRFs were collected synchronously. Each participant completed and recorded ten successful experiments per pair of shoes. Results: The range of motion in the sagittal of the knee joint was reduced with the increase in the longitudinal bending stiffness. Positive work was increased in the sagittal plane of the ankle joint and reduced in the keen joint. The negative work of the knee joint increased in the sagittal plane. The positive work of the metatarsophalangeal joint in the sagittal plane increased. Conclusion: Transitioning from running on a level surface to running uphill, while wearing running shoes with high LBS, could lead to improved efficiency in lower limb function. However, the higher LBS of running shoes increases the energy absorption of the knee joint, potentially increasing the risk of knee injuries. Thus, amateurs should choose running shoes with optimal stiffness when running.

Open Access: Yes

DOI: 10.3390/s24123902

S-shaped fuzzy flip-flops

Rita Lovassy László T. Kóczy

Publication Name: 8th International Symposium of Hungarian Researchers on Computational Intelligence and Informatics Cinti 2007

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: 383-391

Description:

The multilayer perceptron is an artificial neural network that learns nonlinear function mappings. Nonlinear functions can be represented by multilayer perceptrons with units that use nonlinear activation functions. The neurons in the multilayer perceptron networks typically employ sigmoidal activation function. The next state of the J-K fuzzy flipflops (F3) using Fodor, Yager and Dombi operators present S-shaped characteristics. An interesting aspect of F3-s might be that they have a certain convergent behavior when one of their inputs (e.g. J) is exited repeatedly. If J is considered the equivalent of the traditional input of a neuron (with an adder unit applied before J), K might play a secondary modifier's role, or can just be set fix. The paper proposes the investigation of such possible F3-networks as new alternative types of neural networks.

Open Access: Yes

DOI: DOI not available

Evaluating Stakeholder Opinion on Traffic Engineering Devices to Improve Pedestrian Crossing Safety Around Schools in Small Villages

Emese Makó Kurmangaliyev Zhiger

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 58-68

Description:

Despite the greater attention and investment in pedestrian safety measures typically allocated to urban areas, rural villages are frequently overlooked in this respect. A school zone typically applied in urban contexts, refers to a road network surrounding a school where younger pedestrians are likely to be present. The research objective was to gain insight into the traffic preferences of key stakeholders, including teachers, pupils, parents, and representatives of the road authority, regarding the safety of pedestrian crossings in the vicinity of small village schools. A survey was conducted at selected primary schools with relatively high traffic volumes and a high risk of pedestrian accidents. The survey evaluated six different types of designated pedestrian crossings equipped with different traffic engineering devices. The results of the Spearman rank correlation analysis indicate a high degree of alignment between the perspectives of parents and school pupils. At the same time, those of road professionals diverge significantly from those of parents. The teachers’ perspectives exhibit moderate alignment with those of school pupils and road professionals, positioning them in a middle ground between these two groups. The findings demonstrate that the traffic engineering measures deemed safe by road users do not always correspond with those preferred by road professionals. A discrepancy between perceived and actual safety is frequently observed. To address this discrepancy, it is crucial to educate pedestrians about the advantages of safety devices that engineers have identified as effective. Concurrently, it would be prudent for those responsible for the management of roadways to give due consideration to the preferences of pedestrians during their planning activities.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_6

The possible applications of Fuzzy logic for the treatment of conflicts in the dispositional tasks of railway traffic control centers

Tibor Héray Gabor Rozsa László T. Kóczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

the handling of traffic conflicts of trains is rather complicated if full dynamic models are used. Often it is senseless to take into consideration all details of the motion equations and environmental parameters especially as the main parameters, like maximum speed of the trains involved are not exactly known. Also, a large number of noise type variables are always available. The paper proposes the use of the Mamdani type fuzzy rule based reasoning algorithm for handling railway traffic conflicts. The essential point is the granulation of all important parameters into a relatively small number of categories labeled by terms such as small, large, etc. This way the possible decisions for a concrete traffic conflict situation get various fuzzy weights after accumulation of all the fired rules. The final (non-fuzzy) decision is taken by choosing the option with the largest weight. A simplified example is presented for a delay and overtaking type conflict. ©2007 IEEE.

Open Access: Yes

DOI: 10.1109/AFRCON.2007.4401624

Harmonic expansion and nonsmooth dynamics in a circular contact region with combined slip-spin motion

Mate Antali

Publication Name: Nonlinear Dynamics

Publication Date: 2024-05-01

Volume: 112

Issue: 9

Page Range: 6785-6811

Description:

We analyse a rigid body in planar motion while touching a rough plane at a finite-sized, circular contact area. Assuming Coulomb friction between the tangential and normal pressure distributions, the resultant forces and torques can be expressed formally with a nonsmooth dependence on the kinematic variables. In the literature, the exact form of the tangential forces is available for special pressure distributions expressed by transcendent functions; recently, an approximate linear model was introduced. Now, we present a nonlinear extension of the approximation, which can be used effectively to characterise slipping-sticking transitions between the bodies.

Open Access: Yes

DOI: 10.1007/s11071-024-09462-6

Effect of genetic and nongenetic factors on chemical composition of individual milk samples from dromedary camels (Camelus dromedarius) under intensive management

Péter Nagy Jenő Reiczigel Zs N. Fábri Judit Juhász L. Varga

Publication Name: Journal of Dairy Science

Publication Date: 2017-11-01

Volume: 100

Issue: 11

Page Range: 8680-8693

Description:

The aims of the present study were to monitor the changes in gross chemical composition of individual dromedary camel milk over a 5-yr period, to provide reference values, and to determine the effect of genetic and nongenetic factors influencing camel milk composition under intensive management. A total of 1,528 lactating dromedary camels were included in the study. Animals were fed a constant diet and were milked twice a day in a herringbone parlor. Milk samples were collected at monthly intervals using a sampling device and then fat, protein, lactose, total solids (TS), and solids-nonfat (SNF) concentrations of raw camel milk were determined with an automatic milk analyzer. For each milk sample, production parameters were recorded and quantities (grams) of milk constituents were calculated. The overall mean quantity and fat, protein, lactose, SNF, and TS concentrations of the morning milk were 4.0 kg, 2.58%, 2.95%, 4.19%, 8.08%, and 10.46%, respectively. Milk quantity showed a positive correlation with lactose and a negative correlation with all other components. Parity exerted a strong effect on all milk parameters. Primiparous dromedaries (n = 60) produced less milk with higher concentrations of components than did multiparous animals (n = 1,468). Milk composition varied among the 7 breeds tested, but none of the genotypes was found to be superior to the others in this respect. We detected a significant, yet small calf sex-biased difference in milk yield and composition. Stage of lactation and season strongly influenced milk yield and all milk components. We also found a significant interaction between month postpartum (mPP) and month of the year. The concentration of all milk components decreased from 1 to 5 mPP. Later, lactose concentration and quantity continued to decrease parallel with decreasing milk production. The concentration of other components showed a temporary increase in mid lactation, from 6 to 11 mPP, and in late lactation, from 18 to 23 mPP. Mean fat, protein, SNF, and TS concentrations showed a high seasonal variation (9.5 to 28.7%), with the lowest and highest values being measured during summer and winter, respectively. This seasonal variation was independent of nutrition and may reflect an endogenous circannual rhythm. We observed a noticeable variation among years. Dromedary camels could provide a useful in vivo model to study the homeorhetic regulation of mammary cell function by endogenous and environmental factors.

Open Access: Yes

DOI: 10.3168/jds.2017-12814

PROBLEMS AND PROSPECTS FOR LEGAL REGULATION OF INNOVATIONS IN DIGITAL AND INFORMATION TECHNOLOGIES OF THE LABOUR MARKET IN KAZAKHSTAN

Laszlo Vasa Altyn S. Ualtayeva Saule A. Kaliyeva Mukhtar D. Ualtayev

Publication Name: Transformations in Business and Economics

Publication Date: 2024-01-01

Volume: 23

Issue: 3

Page Range: 325-344

Description:

The subject of this research is digital technologies, increasingly applied in the key processes of labour market organisation and the implementation and formalisation of employment relationships. The article provides an analysis of the use of information technologies in the labour sector, forming the basis for researching new forms of employment. The relevance of this study is driven by the need to adapt to the modern digital labour market, dictated by global innovative changes and the application of digital and information technologies, which require normative legal regulation of new forms of employment relationships. These evolving paradigms are poised to shape the future labour market, which is increasingly predicated on electronic formats and the rapid development of new employment constructs, encompassing self-employment, remote work, and freelancing modalities. The scholarly novelty of this study resides in the systematic categorisation and analysis of the principal trends reflecting shifts in the dynamics between employers and employees, influenced by pivotal information technologies in the modern labour market.

Open Access: Yes

DOI: DOI not available