scholarly journals Impact analysis of observation coupling on reliability indices in a geodetic network

2018 ◽  
Vol 106 (1) ◽  
pp. 1-7
Author(s):  
Edward Nowak ◽  
Waldemar Odziemczyk

Abstract An optimally designed geodetic network is characterised by an appropriate level of precision and the lowest possible setup cost. Reliability, translating into the ability to detect blunders in the observations and higher certainty of the obtained point positions, is an important network characteristic. The principal way to provide appropriate network reliability is to acquire a suitably large number of redundant observations. This approach, however, faces limitations resulting from the extra cost. This paper analyses the possibility of providing appropriate reliability parameters for networks with moderate redundancy. A common problem in such cases are dependencies between observations preventing the acquisition of the required reliability index for each of the individual observation. The authors propose a methodology to analyse dependencies between observations aiming to determine the possibility of acquiring the optimal reliability indices for each individual observation or groups of observations. The suggested network structure analysis procedures were illustrated with numerical examples.

2018 ◽  
Vol 105 (1) ◽  
pp. 53-59
Author(s):  
Edward Nowak ◽  
Waldemar Odziemczyk

Abstract Appropriate precision and low cost are the basic conditions that have to be fulfilled by a project of a geodetic network. Reliability, translating into the ability to detect gross errors in the observations and higher certainty of the obtained point position, is an important network characteristic. The principal way to provide appropriate network reliability is to acquire a suitably large number of redundant observations. Optimisation of the observation accuracy harmonisation procedure allowing for the acquisition of an appropriate level of reliability through modification of the observation a priori standard deviations is the focus of this study. Parameterisation of the accuracy harmonisation is proposed. Furthermore, the influence of the individual parameter operation on the effectiveness of the harmonisation procedure is tested. Based on the results of the tests an optimal set of harmonisation parameters which guarantees the maximal efficiency of the harmonisation algorithm is proposed.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 955
Author(s):  
Vasyl Teslyuk ◽  
Andriy Sydor ◽  
Vincent Karovič ◽  
Olena Pavliuk ◽  
Iryna Kazymyra

Technical systems in the modern global world are rapidly evolving and improving. In most cases, these are large-scale multi-level systems and one of the problems that arises in the design process of such systems is to determine their reliability. Accordingly, in the paper, a mathematical model based on the Weibull distribution has been developed for determining a computer network reliability. In order to simplify calculating the reliability characteristics, the system is considered to be a hierarchical one, ramified to level 2, with bypass through the level. The developed model allows us to define the following parameters: the probability distribution of the count of working output elements, the availability function of the system, the duration of the system’s stay in each of its working states, and the duration of the system’s stay in the prescribed availability condition. The accuracy of the developed model is high. It can be used to determine the reliability parameters of the large, hierarchical, ramified systems. The research results of modelling a local area computer network are presented. In particular, we obtained the following best option for connecting workstations: 4 of them are connected to the main hub, and the rest (16) are connected to the second level hub, with a time to failure of 4818 h.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Luisa V. Giles ◽  
Michael S. Koehle ◽  
Brian E. Saelens ◽  
Hind Sbihi ◽  
Chris Carlsten

Abstract Background The physical environment can facilitate or hinder physical activity. A challenge in promoting physical activity is ensuring that the physical environment is supportive and that these supports are appropriately tailored to the individual or group in question. Ideally, aspects of the environment that impact physical activity would be enhanced, but environmental changes take time, and identifying ways to provide more precision to physical activity recommendations might be helpful for specific individuals or groups. Therefore, moving beyond a “one size fits all” to a precision-based approach is critical. Main body To this end, we considered 4 critical aspects of the physical environment that influence physical activity (walkability, green space, traffic-related air pollution, and heat) and how these aspects could enhance our ability to precisely guide physical activity. Strategies to increase physical activity could include optimizing design of the built environment or mitigating of some of the environmental impediments to activity through personalized or population-wide interventions. Conclusions Although at present non-personalized approaches may be more widespread than those tailored to one person’s physical environment, targeting intrinsic personal elements (e.g., medical conditions, sex, age, socioeconomic status) has interesting potential to enhance the likelihood and ability of individuals to participate in physical activity.


2019 ◽  
Vol 34 (6) ◽  
pp. 1737-1741
Author(s):  
Rita Loloçi ◽  
Orneda Gega Hoxha

In this study, we will try to explain the correlation that exists between social ethics and personal ethics. Today’s challenges of human society in the field of ethics, morality and consciousness are not the same in different eras and in nations or groups of states. All three of these domains move more slowly than other processes, but are indispensable in everyday life. State authority in constantly way strive to create legal rules, but their non-compliance with ethic, principles of morality and conscience create major problems in contemporary development. Rapid contemporary developments, especially those in the field of technology and science have brought other concepts to social and personal ethics, but the necessity of their presence always adapting to other conditions has been felt. Today’s man seeks to understand it more in the form of ethics and social education. For example: nudity, morality principles to this phenomenon have changed from generation to generation, once considered shame and today as something private. The reality of the moral and conceptual problems that human and society have had over law, the rights and ethics have changed, concepts have been overthrown, and the way how people have been judged for different situations has evolved. Individual’s education in the traditional societies have been very important issue in his/ her life. That was a lifelong learning process instead. Education’s main purpose was to help the individual during his/her life so that he/she was not only responsible and aware of the environment, but to prepare the individual to fit into real life. In the actual society there are different points of views as far as the moral and civilizing education bonds are concerned. A mutual environment asks for mutual values, but on the other hand it is assumed the need to understand, accept and support even the values which may be different from the individual ones. In other words, the civil education has to treat moral as a separate issue, even though there are different opinions like: moral is a personal choice, moral is given by God, moral is a social agreement, etc. What we should emphasize is the fact that dealing with similar points of view is as important as debating against the opposite ones. It would be very positive if this could be achieved for a common understanding. But does everyone understand what moral, social and personal ethic is? Another question adds to this one: How is the problem of moral going to be treated? And is it necessary to set tasks or duties on moral as well? What features must moral education have in a view of the evolution of society as whole in terms of a new worldview? Today humanity is on the rise and is heading towards great organisation, but one must keep in mind that within this uniformity there is also diversity to be respected. The new worldview must be open to new progress and thinking not only from the content but also from the form.


1970 ◽  
Vol 5 (1) ◽  
Author(s):  
W. F. Al-Khateeb, S. Al-Irhayim, and K. A. Al-Khateeb

The benchmark for the reliability quality of networks depends mainly on the accuracy and comprehensiveness of the reliability parameters. Downtime prediction of a communication system is crucial for the quality of service (QoS) offered to the end-user. Markov model enables analytical calculation of average single figure cumulative downtime over one year. The single average approach, generally, does not adequately describe the wide range of service performance that is likely to be experienced in communications systems due to the random nature of the failure. Therefore, it would be more appropriate to add downtime distribution obtained from network availability models to predict the expected cumulative downtime and other performance parameters among a large number of system populations. The distribution approach provides more comprehensive information about the behavior of the individual systems. Laplace-Stieltjes transform enables analytical solutions for simple network architectures, i.e. the simplex system and the parallel system. This paper uses simulations to determine reliability parameters for complex architecture such as the Multiprotocol Label Switching (MPLS) backbone planned for next-generation Internet. In addition to the single figure downtime, simulations provide other reliability parameters such as probability of zero downtime. The paper also considers the downtime distribution among a population of equally designed systems.Key Words: Reliability, availability, downtime, Multiprotocol label switching


Author(s):  
Samir Okasha

‘Levels of selection’ examines the levels-of-selection question, which asks whether natural selection acts on individuals, genes, or groups. This question is one of the most fundamental in evolutionary biology, and the subject of much controversy. Traditionally, biologists have mostly been concerned with selection and adaptation at the individual level. But, in theory, there are other possibilities, including selection on sub-individual units such as genes and cells, and on supra-individual units such as groups and colonies. Group selection, altruistic behaviour, kin selection, the gene-centric view of evolution, and the major transitions in evolution are all discussed.


Author(s):  
David Duran ◽  
Ester Miquel

Many educational reforms highlight the need for collaboration, understood not only as a competence to be learned but also as a way of learning and teaching. Two types of collaboration can be found in classrooms: peer collaboration and teacher collaboration. The first focuses on how the teacher restructures interactions between pupils organized in pairs or groups. This permits cooperative learning practices, either by peer tutoring or through systems of cooperative learning. By implementing peer collaboration, the teacher is able to develop a new and transformative role which facilitates functions such as continuous assessment or immediate personalized attention, which are more difficult to carry out in environments where a traditional teaching approach is used. However, both the organization of the classroom for peer collaboration and this new teaching role require teacher training. Experiential learning is a key aspect of the training. Different levels of teacher collaboration exist, but the most complete is co-teaching: two teachers planning, implementing, and assessing the same lesson for a group of students. Co–teaching allows teachers to attend to the individual needs of their students; that is why it is such an important tool in inclusive education. Furthermore, it is a learning tool for teachers. Co-teachers can foster mutual observation, reflection, and planning of innovative practices, making working together a form of professional development. However, to ensure that pupils receive better attention and that teachers learn from each other, there has to be teacher training, and again, it must be addressed from an experimental perspective.


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3202
Author(s):  
Alberto Escalera ◽  
Edgardo D. Castronuovo ◽  
Milan Prodanović ◽  
Javier Roldán-Pérez

Modern power distribution networks assume the connection of Distributed Generators (DGs) and energy storage systems as well as the application of advanced demand management techniques. After a network fault these technologies and techniques can contribute individually to the supply restoration of the interrupted areas and help improve the network reliability. However, the optimal coordination of control actions between these resources will lead to their most efficient use, maximizing the network reliability improvement. Until now, the effect of such networks with optimal coordination has not been considered in reliability studies. In this paper, DGs, energy storage and demand management techniques are jointly modelled and evaluated for reliability assessment. A novel methodology is proposed for the calculation of the reliability indices. It evaluates the optimal coordination of energy storage and demand management in order to reduce the energy-not-supplied during outages. The formulation proposed for the calculation of the reliability indices (including the modelling of optimal coordination) is described in detail. The methodology is applied to two distribution systems combining DGs, energy storage and demand management. Results demonstrate the capability of the proposed method to assess the reliability of such type of networks and emphasise the impact of the optimal coordination on reliability.


1998 ◽  
Vol 2 (4) ◽  
pp. 243-250 ◽  
Author(s):  
Robert P. Abelson ◽  
Nilanjana Dasgupta ◽  
Jaihyun Park ◽  
Mahzarin R. Banaji

It is contended that perceptions of groups are affected by particular variables that do not apply to individuals (e.g., intragroup similarity and proximity). Importantly, the perception of outgroup threat has incomplete analogs at the individual level. Results from 3 studies support predictable distinctions between representations of individuals and of groups. Study I showed that priming of the word they produces more extreme negative judgments of the protagonist(s) in a story about 4 individuals acting jointly than in the same story with a single person acting alone. The opposite result holds for priming with the word he. Study 2, with Korean participants, demonstrates that actions by individuals or groups elicit differing preferences for redress. Individual responses (e.g., getting mad) to an individual racial insult (e.g., a snub by a waitress) are preferred to collective responses (e.g., circulating a petition), whereas the reverse preferences holdfor a group insult (e.g., taunts from a gang of White youths). In Study 3, cues to the entitivity of a group are introduced. This concept, introduced by Donald Campbell (1958), distinguishes different degrees of “groupness. ” Visual depictions of collections of unfamiliar humanoid creatures (greebles) were used to convey that they were either similar or dissimilar and either proximate or scattered. Results confirm the expectation that similarity and proximity-two entitive conditions-elicit more negative judgments of the group. Attention to other cues for entitivity may enrich social psychological views of stereotyping and prejudice by focusing on perceptions of groups as coordinated actors with the potential to bring about negative consequences. Such experiments point to the needfor greater research focus on the vastly understudied but fundamental problem of the social cognition of group behavior.


2021 ◽  
Author(s):  
Marc Pouilly ◽  
Sergio Gomez ◽  
Christophe Pecheyrann ◽  
Sylvain Berail ◽  
Gustavo Alvarez ◽  
...  

Studying the distribution of organisms and their movements is fundamental to understand population dynamics. Most studies indicated that crocodilians do not move around much but several studies demonstrated that some species showed movement patterns. Detection of these movements along the individual life is still a challenge. In this study we analyzed the variation of strontium isotopic ratio (87Sr/86Sr) in the femur bones of 70 Caiman yacare individuals caught in 16 sites located in five hydrological sectors of the Beni river floodplain in Bolivia. Our results demonstrated for the first time that such a methodology could yield indications about the capture sites and reconstruct individual life history. Analyses of the outer part of the femur of 70 individuals showed that capture sites could be differentiated between sectors and even between sites or groups of sites in each sector. Studies of complete 87Sr/86Sr profiles along the femur, representing entire life of the individual, were performed on 33 yacares. We found that most of the individuals did not show any significant isotopic variation throughout their lives. This absence of variation could result from a high fidelity to the birth site, and/or from an insignificant isotopic variation between the water bodies through which the animal has potentially moved. However, 24% of the analyzed individuals presented significant variations that can be considered as movements between different habitats. Based on the observed low proportion of moving yacares, we advocated that each water body should be considered an individual management unit.


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