Journal articles on the topic 'Degree Discipline: Statistics and Operations Research'
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Doran, Desmond, Alex Hill, Steve Brown, Emel Aktas, and Markku Kuula. "Operations Management Teaching." Industry and Higher Education 27, no. 5 (October 2013): 375–87. http://dx.doi.org/10.5367/ihe.2013.0172.
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This paper explores the relevance to industry's needs of operations management (OM) teaching in higher education, by researching the content of OM modules delivered by UK academics and comparing the results of this research with the views of business practitioners having had first-hand experience of OM teaching on MBA programmes. To determine whether a gap exists in terms of the importance placed on key content areas, the views of OM academics and practitioners were empirically tested using an online survey instrument. The findings indicate that although there is a broad degree of cohesion among academics relating to module content there are gaps between academics and practitioners in terms of the relative importance of key content areas. Such differences are most evident with regard to supply chain management, capacity management, inventory control and lean production tools and techniques. In this regard, the results provide a backdrop for the development of this important subject discipline to ensure that what is taught in the lecture theatre is valued in the business environment.
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Mitchell, Joelle, and Alice Turnbull. "Identifying pan-industry common contributors to major accident events." APPEA Journal 60, no. 1 (2020): 41. http://dx.doi.org/10.1071/aj19036.
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Analysis of incident investigation findings as a means of identifying common precursors or causal factors is a common topic of safety research. Historically this type of research has been conducted through a single lens, depending on the researcher’s discipline, with incidents analysed in accordance with a favoured theory, or grouped according to industry or region. This has led to the development of numerous frameworks and taxonomies that attempt to predict or analyse events at various levels of granularity. Such theories and disciplines include safety culture and climate, human factors, human error, management systems, systems theory, engineering and design, chemistry and maintenance. The intent of such research is ostensibly to assist organisations in understanding the degree to which their operations are vulnerable to known precursors or causal factors to major accident events and to take proactive measures to improve the safety of their operations. However, the discipline-specific nature of much of this research may limit its application in practice. Specific frameworks and taxonomies may be of assistance when organisations have identified a relevant area of vulnerability within their operations, but are unlikely to assist organisations in identifying those vulnerabilities in the first place. This paper seeks to fill that gap. A multidisciplinary approach was taken to identify common causal factors. Investigation reports published by independent investigation agencies across various industries were analysed to determine common causal factors regardless of discipline or industry.
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Wynn, Henry, and Irena Ograjenšek. "Is statistics becoming the number one discipline for business and industry?" Quality and Reliability Engineering International 26, no. 8 (December 2010): 789–93. http://dx.doi.org/10.1002/qre.1152.
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Hu, Jiming, and Yin Zhang. "Measuring the interdisciplinarity of Big Data research: a longitudinal study." Online Information Review 42, no. 5 (September 10, 2018): 681–96. http://dx.doi.org/10.1108/oir-12-2016-0361.
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Purpose The purpose of this paper is to measure the degree of interdisciplinary collaboration in Big Data research based on the co-occurrences of subject categories using Stirling’s diversity index and specialization index. Design/methodology/approach Interdisciplinarity was measured utilizing the descriptive statistics of disciplines, network indicators showing relationships between disciplines and within individual disciplines, interdisciplinary communities, Stirling’s diversity index and specialization index, and a strategic diagram revealing the development status and trends of discipline communities. Findings Comprehensively considering all results, the degree of interdisciplinarity of Big Data research is increasing over time, particularly, after 2013. There is a high level of interdisciplinarity in Big Data research involving a large number of disciplines, but it is unbalanced in distribution. The interdisciplinary collaborations are not intensive on the whole; most disciplines are aggregated into a few distinct communities with computer science, business and economics, mathematics, and biotechnology and applied microbiology as the core. Four major discipline communities in Big Data research represent different directions with different development statuses and trends. Community 1, with computer science as the core, is the most mature and central to the whole interdisciplinary network. Accounting for all network indicators, computer science, engineering, business and economics, social sciences, and mathematics are the most important disciplines in Big Data research. Originality/value This study deepens our understanding of the degree and trend of interdisciplinary collaboration in Big Data research through a longitudinal study and quantitative measures based on two indexes. It has practical implications to study and reveal the interdisciplinary phenomenon and characteristics of related developments of a specific research area, or to conduct comparative studies between different research areas.
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KRASNOZHON, O., N. KRAVCHENKO, V. MATSIUK, and V. KOVALENKO. "ELEMENTS OF COMPUTER SUPPORT FOR THE STUDY OF THE TOPIC «LEAST SQUARES METHOD»." Scientific papers of Berdiansk State Pedagogical University Series Pedagogical sciences 1, no. 2 (October 6, 2022): 204–13. http://dx.doi.org/10.31494/2412-9208-2022-1-2-204-213.
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The article contains a study of the methodological problem of developing the components of an effective computer-oriented methodological system for teaching the discipline «Theory of Probability with Elements of Mathematical Statistics», which is provided for in the training plan for future teachers of mathematics. The methodical and procedural issues of implementing the method of least squares to determine the functional dependence between the characteristics of the sample of the general population in the mathematical software environment Mathcad are considered. Examples of solving problems of equalizing the values of the characteristics of the sample of the general population along a polynomial of the first degree (linear dependence), a polynomial of the second degree (parabola) and a polynomial of the third degree (cubic parabola) are given. A brief review of the scientific, educational and methodical literature, which is used during the teaching of the course of probability theory with elements of mathematical statistics, was carried out, the expediency of using mathematical software during the development of the content of the specified discipline was substantiated. The provision on the need to develop a complex of test tasks of various levels of complexity from probability theory with elements of mathematical statistics for the purpose of objective assessment of students' educational achievements has been formulated. The article formulates conclusions and outlines the directions of further scientific and pedagogical research in the field of implementation of mathematical statistics methods when finding statistical estimates of a sample of values of a random variable of the general totality. The methodological developments given in the article can be useful to students for the organization and activation of independent scientific and pedagogical activities, teachers of secondary educational institutions, leaders of optional and group work of students, teachers of the course of probability theory with elements of mathematical statistics of pedagogical higher educational institutions. Key words: least squares method, probability theory, elements of mathematical statistics, statistical sample, general totality.
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Piharsih, Piharsih, and Ruhita Ruhita. "HUBUNGAN DISIPLIN DAN MOTIVASI KERJA GURU DENGAN PRESTASI BELAJAR SISWA SMP NEGERI DI KECAMATAN KETANGGUNGAN KABUPATEN BREBES." Edum Journal 4, no. 2 (December 21, 2021): 38–53. http://dx.doi.org/10.31943/edumjournal.v4i2.89.
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Abstract-Educational operations in educational units have several objectives that must be achieved, especially at the level of basic education which will become the foundation for continuing education. The main objective is student achievement. High student learning achievement is one indicator of the quality of education. Many things are thought to have a relationship with student achievement. Among others, discipline and teacher work motivation. Therefore, the focus of this study is to determine the degree of relationship between teacher discipline and work motivation with student achievement, both individually and simultaneously. The research method used is descriptive and verification methods, with data collection techniques using a Likert scale questionnaire, to 60 teachers. Processing of research results using regression analysis techniques. The significance test used the F-test. The results showed that: (1) There is a positive and significant relationship between teacher work discipline and student achievement. (2) There is a positive and significant relationship between teacher work motivation and student achievement. (3) There is a positive and significant relationship between work discipline and teacher work motivation (together) simultaneously with student achievement. Starting from these conditions the authors suggest: (1) The results of the study have shown that operationally there is a significant relationship between teacher work discipline and student achievement. This means that improving the conditions of teacher work discipline can encourage increased student achievement. The condition of teacher work discipline based on the respondent's assessment is in a good category, except that discipline towards the rules is very good. The author suggests that to encourage the improvement of student achievement, so that time discipline and responsibility are increased through exemplary and tightened supervision from the principal. (2) According to the results of the study, the teacher work motivation factor also has a relationship with student achievement. According to the respondent's assessment, the work motivation of teachers is in the very good category, except for the aspects of the motivation and understanding of the teacher's school goals. Therefore, to maximize student learning achievement, it is recommended to increase the motivation for the teacher through clear job descriptions and involve the teacher in setting school goals so that the teacher becomes more aware of the goals that the school must achieve.
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Mandjes, M., and M. Nuyens. "SOJOURN TIMES IN THE M/G/1 FB QUEUE WITH LIGHT-TAILED SERVICE TIMES." Probability in the Engineering and Informational Sciences 19, no. 3 (June 22, 2005): 351–61. http://dx.doi.org/10.1017/s0269964805050205.
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The asymptotic decay rate of the sojourn time of a customer in the stationary M/G/1 queue under the foreground–background (FB) service discipline is studied. The FB discipline gives service to those customers that have received the least service so far. We prove that for light-tailed service times, the decay rate of the sojourn time is equal to the decay rate of the busy period. It is shown that FB minimizes the decay rate in the class of work-conserving disciplines.
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S. Behara, Ravi, Sunil Babbar, and Philip Andrew Smart. "Leadership in OM research: a social network analysis of European researchers." International Journal of Operations & Production Management 34, no. 12 (October 28, 2014): 1537–63. http://dx.doi.org/10.1108/ijopm-08-2013-0390.
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Purpose – The purpose of this paper is to examine the leadership role of authors, institutions, and countries based on research co-authorship networks in the field of operations management (OM) and ranks European authors, institutions, and countries using network centrality measures. It also identifies the primary research areas of each of the leading European authors and maps the areas that European research in general has focussed most on. Design/methodology/approach – Based on co-authorships in publications appearing in a representative set of three leading OM journals over the 15-year period of 1998-2012, network measures of total degree centrality and betweenness centrality are used to identify influential European agents serving as leaders and bridge builders in OM research. Keyword analysis is used to identify the dominant areas of OM research in Europe as well as the primary areas of research of the leading authors. Findings – With UK, Spain, The Netherlands, and Italy accounting for the dominant share of authorship of papers in the journal set, many authors and institutions from these countries are also found to rank high on network centrality measures. While certain authors, institutions, and countries are found ranking high on total degree centrality based on number of direct connections in the network, others are found to play uniquely important roles as gatekeepers and bridge builders in network relationships. The body of research is found to be focussed most on the area of supply chain management. It is also found to be focussed more on manufacturing than service. Research limitations/implications – The examination of networks in this study based on co-authorships in publications in the set of three leading journals: Journal of Operations Management, International Journal of Operations & Production Management, and Production and Operations Management, is not all encompassing as there are likely other co-authorship relationships of OM researchers that go beyond publications in this set of journals. Practical implications – Co-authorship of papers in the leading academic journals in a discipline provides a window on patterns of collaboration among key researchers within that academic community. The findings of this study inform the community of stakeholders on who the leading European agents in OM research are, what the primary areas of research of the leading European authors are, and areas that European research has focussed most on. Originality/value – This is the first study of its kind that identifies and maps key European authors, institutions, and countries based on the analysis of co-authorship networks of researchers who have published in a set of leading OM journals that are considered to be among the most relevant outlets in the field of OM. It also maps the primary areas of research.
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Davidovitch, Nitza, Michael Byalsky, Dan Soen, and Zilla Sinuani-Stern. "The Cost Of More Accessible Higher Education: What Is The Monetary Value Of The Various Academic Degrees?" Contemporary Issues in Education Research (CIER) 6, no. 1 (January 2, 2013): 37. http://dx.doi.org/10.19030/cier.v6i1.7602.
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One of the main reasons for acquiring a Bachelor's Degree is the perception of higher education as a means of improving graduates' financial status. In light of the increased accessibility of higher education, a growing number of students hope to use their studies as a financial springboard. In the current study we sought to examine this perception and to check whether and to what degree baccalaureate degrees indeed improve graduates' financial situation. In cooperation with Israel's Central Bureau of Statistics we gathered data on 6,091 graduates who completed their studies at the Ariel University Center during 2000-2008. Data analysis included exploring graduates' rate of employment and monthly salary from the day they began their academic studies until eight years later. We divided and distinguished between graduates by discipline and gender. The findings show that graduates earn almost three times the national average salary (and five times the median salary) and indicate employment rates of nearly 100%. Analysis of findings by discipline indicates that the most profitable fields are computer sciences and mathematics, engineering, and architecture. Salaries in the natural and social sciences and in the humanities are significantly lower both compared to the former fields and to the national average salary, at least for this eight year span. Analysis of the data by sex showed that the rate of employment among men is 12% higher than among women and that there is a disparity in employment within each discipline as well. Research conclusions show that academic degrees per se are not a guarantee of financial or occupational security. Employees with degrees in the social sciences and the humanities may find that their pay is no higher than those with no degree. One of the implications of this issue, already evident at this stage is that students are attempting to attain higher degrees in the hope of improving their financial status. The equation of a higher education with a higher income seems to involve other components as well, such as graduates' field of study, seniority on the job, and field of occupation.
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Altman, Eltan, and Uri Yechiali. "Polling in a Closed Network." Probability in the Engineering and Informational Sciences 8, no. 3 (July 1994): 327–43. http://dx.doi.org/10.1017/s0269964800003442.
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We consider a closed queueing network with a fixed number of customers, where a single server moves cyclically between N stations, rending service in each station according to some given discipline (Gated, Exhaustive, or the Globally Gated regime). When service of a customer (message) ends in station j, it is routed to station k with probability Pjk. We derive explicit expressions for the probability generating function and the moments of the number of customers at the various queues at polling instants and calculate the mean cycle duration and throughput for each service discipline. We then obtain the first moments of the queues' length at an arbitrary point in time. A few examples are given to illustrate the analysis. Finally, we address the problem of optimal dynamic control of the order of stations to be served.
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Carneiro da Cunha Custódio, Leonardo, and Jonas Gomes da Silva. "Profile of Supervised Internship Reports of the FT/UFAM Industrial Engineering Course." International Journal for Innovation Education and Research 8, no. 3 (March 1, 2020): 175–84. http://dx.doi.org/10.31686/ijier.vol8.iss3.2221.
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The article analyzes the profile of the Supervised Internship reports delivered by students of the Industrial Engineering course at the Faculty of Technology of the Federal University of Amazonas (FT/UFAM), to provide useful information to the course department, as well as providing knowledge and reflection on how the discipline has been approached over time. The research is applied, documentary, using descriptive statistics along with data obtained from the collection of internship reports approved between 2008/1 to 2018/1. After analyzing the results, the main conclusions were that the average score of the 469 reports is 8.56, the industry is the segment in which the majority of the internships (76%) were carried out, while the Operations Engineering, and Production Process, Organizational Engineering, Quality Engineering, Logistics, and Work Engineering were the main areas of Industrial Engineering in which the students interned.
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Òzekici, Süleyman, Jingwen Li, and Fee Seng Chou. "Waiting Time in M/G/1 Queues with Impolite Arrival Disciplines." Probability in the Engineering and Informational Sciences 9, no. 2 (April 1995): 255–67. http://dx.doi.org/10.1017/s0269964800003843.
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We consider a queueing system where arriving customers join the queue at some random position. This constitutes an impolite arrival discipline because customers do not necessarily go to the end of the line upon arrival. Although mean performance measures like the average waiting time and average number of customers in the queue are the same for all such disciplines, we show that the variance of the waiting time increases as the arrival discipline becomes more impolite, in the sense that a customer is more likely to choose a position closer to the server. For the M/G/1 model, we also provide an iterative procedure for computing the moments of the waiting time distribution. Explicit computational formulas are derived for an interesting special model where a customer joins the queue either at the head or at the end of the line.
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Tinungki, Georgina Maria, Budi Nurwahyu, Agus Budi Hartono, and Powell Gian Hartono. "Team-Assisted Individualization Type of the Cooperative Learning Model for Improving Mathematical Problem Solving, Communication, and Self-Proficiency: Evidence from Operations Research Teaching." Education Sciences 12, no. 11 (November 17, 2022): 825. http://dx.doi.org/10.3390/educsci12110825.
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The purpose of this study is to analyze the increase in the mathematical problem-solving (MPS), mathematical communication (MC), and self-proficiency (SPr) abilities of students by applying the team-assisted individualization type (TAI) of the cooperative and conventional learning models for the experimental and control classes. This is a quasi-experimental study comprising a sample of 50 and 42 students studying for an undergraduate degree in statistics for the experimental and control classes, respectively. Students’ mathematical prior knowledge (MPK) is grouped into three levels, namely high, medium, and low. The instruments used are the MPS test, the MC test, the self-proficiency scale, and observation sheets. Statistical analysis instruments used are parametric and non-parametric statistics, such as prerequisite tests for normality and homogeneity of variance, mean difference tests in two or more groups, the post hoc test, and description and interaction tests. The results showed an increase in MPS, MC, and SPr in the experimental class, which is higher than in the control class. Furthermore, there is no interaction between the experimental and control classes despite a significant correlation between MPS, MC, and MPS. These findings are relevant to mathematics and statistics teaching because it has been proven to improve students’ MPS, MC, and SPr; hence, learning outputs can be achieved objectively, specifically for operations research teaching.
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Wang, Xiaoyuan, Jianqiang Wang, Jinglei Zhang, and Xuegang Jeff Ban. "Lane-changing model with dynamic consideration of driver's propensity." International Journal of Modern Physics C 26, no. 02 (February 2015): 1550015. http://dx.doi.org/10.1142/s0129183115500151.
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Lane-changing is the driver's selection result of the satisfaction degree in different lane driving conditions. There are many different factors influencing lane-changing behavior, such as diversity, randomicity and difficulty of measurement. So it is hard to accurately reflect the uncertainty of drivers' lane-changing behavior. As a result, the research of lane-changing models is behind that of car-following models. Driver's propensity is her/his emotion state or the corresponding preference of a decision or action toward the real objective traffic situations under the influence of various dynamic factors. It represents the psychological characteristics of the driver in the process of vehicle operation and movement. It is an important factor to influence lane-changing. In this paper, dynamic recognition of driver's propensity is considered during simulation based on its time-varying discipline and the analysis of the driver's psycho-physic characteristics. The Analytic Hierarchy Process (AHP) method is used to quantify the hierarchy of driver's dynamic lane-changing decision-making process, especially the influence of the propensity. The model is validated using real data. Test results show that the developed lane-changing model with the dynamic consideration of a driver's time-varying propensity and the AHP method are feasible and with improved accuracy.
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Feng, Yarong, Hosam Mahmoud, and Ludger Rüschendorf. "DEGREE PROFILE OF HIERARCHICAL LATTICE NETWORKS." Probability in the Engineering and Informational Sciences 31, no. 1 (September 13, 2016): 60–82. http://dx.doi.org/10.1017/s0269964816000310.
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We study the degree profile of random hierarchical lattice networks. At every step, each edge is either serialized (with probability p) or parallelized (with probability 1−p). We establish an asymptotic Gaussian law for the number of nodes of outdegree 1, and show how to extend the derivations to encompass asymptotic limit laws for higher outdegrees. The asymptotic joint distribution of the number of nodes of outdegrees 1 and 2 is shown to be bivariate normal. No phase transition with p is detected in these asymptotic laws.For the limit laws, we use ideas from the contraction method. The recursive equations which we get involve coefficients and toll terms depending on the recursion variable and thus are not in the standard form of the contraction method. Yet, an adaptation of the contraction method goes through, showing that the method has promise for a wider range of random structures and algorithms.
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Domicolo, Carly, and Hosam Mahmoud. "DEGREE-BASED GINI INDEX FOR GRAPHS." Probability in the Engineering and Informational Sciences 34, no. 2 (March 14, 2019): 157–71. http://dx.doi.org/10.1017/s0269964819000044.
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AbstractIn Balaji and Mahmoud [1], the authors introduced a distance-based Gini index for rooted trees. In this paper, we introduce a degree-based Gini index (or just simply degree Gini index) for graphs. The latter index is a topological measure on a graph capturing the proximity to regular graphs. When applied across the random members of a class of graphs, we can identify an average measure of regularity for the class. Whence, we can compare the classes of graphs from the vantage point of closeness to regularity.We develop a simplified computational formula for the degree Gini index and study its extreme values. We show that the degree Gini index falls in the interval [0, 1). The main focus in our study is the degree Gini index for the class of binary trees. Via a left-packing transformation, we show that, for an arbitrary sequence of binary trees, the Gini index has inferior and superior limits in the interval [0, 1/4]. We also show, via the degree Gini index, that uniform rooted binary trees are more regular than binary search trees grown from random permutations.
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Krzesinski, A. E., and R. Schassberger. "Product Form Solutions for Multiserver Centers with Hierarchical Concurrency Constraints." Probability in the Engineering and Informational Sciences 6, no. 2 (April 1992): 147–56. http://dx.doi.org/10.1017/s0269964800002412.
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We establish the quasireversibility of a certain exponential multiserver queue. The queuing discipline imposes restrictions on the numbers of customers of different classes and subclasses that can be served simultaneously. Customer loss is also allowed. Due to its quasireversibility the queue can be used as a node in a product form network. Our work generalizes work of Le Boudec, Krzesinski, and Crosby.
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Buitenhek, Ronald, Geert-Jan van Houtum, and Jan-Kees van Ommeren. "On First-Come First-Served Versus Random Service Discipline in Multiclass Closed Queueing Networks." Probability in the Engineering and Informational Sciences 11, no. 3 (July 1997): 313–26. http://dx.doi.org/10.1017/s026996480000485x.
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We consider multiclass closed queueing networks. For these networks, a lot of work has been devoted to characterizing and weakening the conditions under which a product-form solution is obtained for the steady-state distribution. From this work, it is known that, under certain conditions, all networks in which each of the stations has either the first-come first-served or the random service discipline lead to the same (product-form expressions for the) steady-state probabilities of the (aggregated) states that for each station and each job class denote the number of jobs in service and the number of jobs in the queue. As a consequence, all these situations also lead to the same throughputs for the different job classes. One of the conditions under which these equivalence results hold states that at each station all job classes must have the same exponential service time distribution. In this paper, it is shown that these equivalence results can be extended to the case with different exponential service times for jobs of different classes, if the network consists of only one single-server or multiserver station. This extension can be made despite of the fact that the network is not a product-form network anymore in that case. The proof is based on the reversibility of the Markov process that is obtained under the random service discipline. By means of a counterexample, it is shown that the extension cannot be made for closed network with two or more stations.
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Nataraja, Sundaram, and Beau Grantham. "RIVALRY AMONGST TOP-FIVE MAJOR AIRLINES IN THE U.S. MARKET." International Journal of Research -GRANTHAALAYAH 8, no. 7 (July 29, 2020): 160–73. http://dx.doi.org/10.29121/granthaalayah.v8.i7.2020.596.
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Understanding the economic characteristics of the U.S. airline industry, assessing the degree of competition/rivalry among the competing airline businesses in the U.S. airline industry, and (3) making recommendations to the airlines and to the consumers of air transportation are the primary objectives of this research study. The authors analyze the rivalry among major U.S. airlines operating in the domestic market using datasets extracted from Bureau of Transportation Statistics for operations during a 12-month period ending in May 2019. Amongst the 17 major U.S. airlines, whose annual operational revenue is over $1 billion, a set of top-five airlines has been identified using the percentage of their marketshare. The research findings indicate that these five major airlines have an intense rivalry in the U.S. domestic market in terms of number of markets served, number of departures made, number of passengers transported, amount of cargo carried, load factor, revenue and cost of operations, profit and loss, and net income earned. Hence, these airlines put pressure on one another and limit each other’s profit potential.
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Zazanis, Michael A. "THE TIME-TO-EMPTY FOR TANDEM JACKSON NETWORKS." Probability in the Engineering and Informational Sciences 18, no. 4 (October 2004): 493–502. http://dx.doi.org/10.1017/s0269964804184052.
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We derive the distribution of the time-to-empty for an open tandem Jackson network assuming that while in equilibrium at time 0, the arrival stream is suddenly shut off. The analysis is based on analogous results regarding the distribution of the time-to-empty for the corresponding closed tandem Jackson network. The results obtained are used in the analysis of a two-class tandem Jackson network with FIFO discipline in which customers of the second class have negligible service times.
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Rana, Naeem Akhtar, and Naeem Tuba. "Failure to get Admissions in a Discipline of their own Choice: Voices of Dejected Students." Journal of Education and Educational Development 4, no. 1 (May 30, 2017): 7. http://dx.doi.org/10.22555/joeed.v4i1.987.
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<p>Attaining a professional engineering degree is a dream of many pre-engineering intermediate students in Pakistan. Several students face scarcity of resources to accomplish and enliven their dreams of getting admission into an engineering institute, which results in great hardships and turmoil for them. The literature reveals that quantitative work in this area has been done to some extent, which restricts the comprehension of deeper understanding, profound feelings, perceptions, personal meanings, effects and experiences surrounding this dilemma at the time of rejection. This study has tried to ferret out the experiences of the students who could not get admission in the field of their own interest and went through the phase of uncertainty concerning their future. The research is grounded in the tradition of hermeneutic phenomenology as guided by Heidegger (1962), Gadamer (1960/2003), Casey (1993) and Levinas (1961/2004). By calling forth the philosophical and methodological tenets of this approach, the endeavor was to uncover the lived experiences of the students at the time of failure as well as how they felt about their future. A group of five students from the University of Karachi (Department of Statistics), who could not qualify in the Entrance test of a well renowned Engineering University in Karachi and later joined BS program in Actuarial Sciences, were interviewed for this research. The insights of the study reflect that lack of opportunities and failure result in a great set back for the students and harbor negative feelings in them towards education and its system. The study recommends the need to establish new public sector universities to fulfill the needs of the students to achieve their targets and simultaneously to groom them as an asset for the country.</p>
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Shalmon, Michael. "Analysis of the GI/GI/1 Queue and its Variations via the LCFS Preemptive Resume Discipline and Its Random Walk Interpretation." Probability in the Engineering and Informational Sciences 2, no. 2 (April 1988): 215–30. http://dx.doi.org/10.1017/s0269964800000747.
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The unfinished work at arrival instants (FCFS waiting time) can be computed via the LCFS preemptive resume discipline. Analyzing the GI/GI/1 queue in this way gives full interpretation in queuing theoretic language to Feller's analysis of the fluctuations of the random walk. Also, this approach leads naturally to stochastic decompositions for the queue with set-up times, and for other variations of the standard queue. For the M/G/1 queue, the derivations are qualitative, and there are additional connections to branching processes.
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Korneeva, Yana Aleksandrovna, Lyudmila Ivanovna Shakhova, and Anna Konstantinovna Sorvanova. "Professional competences of mediators with varying degree of success in conduct of conciliation procedures." Психология и Психотехника, no. 4 (April 2020): 53–77. http://dx.doi.org/10.7256/2454-0722.2020.4.34625.
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Mediation has become an increasingly popular reconciliation procedure that allows increasing the psychological security of parties to the conflict in educational and social environment, as well as legal practice. The profession of mediator is highly demanded; however, the questions of professional competence of the specialists and requirements to their personality did not receive due coverage in the scientific literature. The goal of this research consist in development of the model of professional competence and assessment of the level of professional competences of mediators with varying degree of success in conduct of reconciliation procedures. A list of professional competences and their indicators mediators, considering the professional standard – “Specialist in the Field of Mediation (mediator)”. The research involved 42 mediators from Arkhangelsk Region. The following methods were applied: questionnaire (the author developed an original questionnaire for self-assessment of professional competences of the mediator), and psychological testing based on the Five-Factor Model of Personality of Costa and McCrae's in adaptation of M. V. Bodunov and S. D. Biryukov. Statistical processing was carried out via the method of descriptive statistics, correlation and step-type multivariate regression analyses (Pearson's chi-squared test) using the software SPSS 23.00 (license agreement No.Z125-3301-14). The following conclusion was made: the model of professional competences of mediator includes communication skills, conflict management, case study, planning, and self-control. The author developed and tested the questionnaire for self-assessment of professional competences of mediators that can be implemented via 360-degree feedback method. It is established that the successful outcome of reconciliation procedure is affected by such professional competences as self-control and communication skills. Out of the list of professionally important qualities of mediator, the author highlights activity, concreteness, openness, self-restraint, self-discipline, responsibility and sociability as directly related to the success of reconciliation procedures.
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Jagerman, David L., and Bhaskar Sengupta. "A Functional Equation Arising in a Queue With a Gating Mechanism." Probability in the Engineering and Informational Sciences 3, no. 3 (July 1989): 417–33. http://dx.doi.org/10.1017/s0269964800001285.
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Our primary aim in this paper is to study a functional equation that arises in a problem of queueing. Consider a queue with compound Poisson arrivals and general service times with a gating mechanism. The gating mechanism takes in at most m(≤∞) customers at a time for service and serves these customers according to the processor-sharing discipline. In this paper, we examine various performance characteristics for this queue. The characteristics include waiting-time distribution, queue-length distribution, time spent with the server, and batch-size distribution for service.
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Aalto, Samuli, Urtzi Ayesta, and Rhonda Righter. "PROPERTIES OF THE GITTINS INDEX WITH APPLICATION TO OPTIMAL SCHEDULING." Probability in the Engineering and Informational Sciences 25, no. 3 (May 17, 2011): 269–88. http://dx.doi.org/10.1017/s0269964811000015.
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We consider the optimal scheduling problem for a single-server queue without arrivals. We allow preemptions, and our purpose is to minimize the expected flow time. The optimal nonanticipating discipline is known to be the Gittins index policy, which, however, is defined in an implicit way. Until now, its general behavior in this specific problem has been characterized only in a few special cases. In this article, we give as complete a characterization as possible. It turns out that the optimal policy always belongs to the family of multilevel processor sharing disciplines.
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Volkova, Nataliia P., and Olena O. Lavrentieva. "THE FORMATION OF FUTURE PSYCHOLOGISTS’ PROFESSIONAL ASPIRATIONS IN THE PROCESS OF STUDYING THE DISCIPLINE «PEDAGOGY AND PSYCHOLOGY OF HIGHER SCHOOL»." Bulletin of Alfred Nobel University Series "Pedagogy and Psychology" 2, no. 22 (2021): 164–75. http://dx.doi.org/10.32342/2522-4115-2021-2-22-19.
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In the article the problem of theoretical and methodological aspects, factors and means of forming the future psychologists’ professional aspirations have been revealed. The characteristics, content and essence of the «aspirations» and «professional aspirations» concepts have been clarified and analysed. It has been determined that professional aspirations are a complex personal phenomenon, which is a set of requirements, expectations that a person feels and experiences in relation to his/her own professional life and his/her own future. It is the person’s ability to model the desired future in accordance with the expectations of society, without giving up their own potentials and plans, as well as certain individual standards of future life, which a person already deserves today. The components of professional aspirations have been shown. Among them are the motivational component (the complex of motives, needs, guidelines in professional activities), the cognitive one (knowledge of the content and structure of professional aspirations, their impact on professional readiness and success of the specialist, as well as the methods and technologies of their formation), the activity one (the degree of formation of the organizational, psychology and diagnostic, prognostic, reflexive, and communicative skills) and the reflexive one (the structure of reflexive, critical and creative thinking of future psychologists). It has been established that among the components of the educational program of future psychologists’ professional training, the discipline «Pedagogy and psychology of higher school» has significant potential in the formation of students’ professional aspirations. For that, the educational process should be organized taking into account such requirements as subjectivity, dialogical nature, developmental orientation, interaction in the subsystems «lecturer - student», «student - student», which is based on co-creation and cooperation, equality of positions, empathy. It has been empirically confirmed that the formation of master degree students’ professional aspirations is possible thanks to the updated content, as well as by way of providing a link between theoretical and practical preparation in the teaching of this discipline. In the article it has been shown that, for this purpose, it is advisable to combine lectures (lecture-conversation, lecturediscussion, problem lecture), seminars (seminar in «small groups», seminar - reflection) and practical classes using a number of pedagogical technologies, namely: dialogue and discussion ones (dispute, debate, round table), game ones (role-games, simulation games, projecting-ingame), training ones (developmental, game, and simulation trainings), problem and situation learning (case-studies, projects, portfolios), blended learning (thematic blog, web-quest, search online, webinar). The diagnostic data obtained upon completion made it possible to state the positive and statistically significant dynamics in the components of future psychologists’ professional aspirations. The conclusion has been made on the expediency of construction of conceptual bases of the information and development environment of HEI, which is aimed at professional training of highly skilled and professionally self-realized experts and development of their professional aspirations.
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Miyoshi, Naoto, Mariko Ogura, Takeya Shigezumi, and Ryuhei Uehara. "SUBEXPONENTIAL INTERVAL GRAPHS GENERATED BY IMMIGRATION–DEATH PROCESSES." Probability in the Engineering and Informational Sciences 24, no. 2 (March 18, 2010): 289–301. http://dx.doi.org/10.1017/s0269964809990283.
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We propose a simple model of random interval graphs generated by immigration–death processes (also known as M/G/∞ queuing processes), where the length of each interval follows a subexponential distribution, and provide a condition under which the stationary degree distribution is also subexponential. Furthermore, we consider the conditional expectation of the cluster coefficient of a vertex given the degree and show that it vanishes in the limit as the degree goes to infinity under the same condition as that for obtaining the tail asymptotics of the stationary degree distribution.
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Deijfen, Maria, and Willemien Kets. "RANDOM INTERSECTION GRAPHS WITH TUNABLE DEGREE DISTRIBUTION AND CLUSTERING." Probability in the Engineering and Informational Sciences 23, no. 4 (July 14, 2009): 661–74. http://dx.doi.org/10.1017/s0269964809990064.
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A random intersection graph is constructed by assigning independently to each vertex a subset of a given set and drawing an edge between two vertices if and only if their respective subsets intersect. In this article a model is developed in which each vertex is given a random weight and vertices with larger weights are more likely to be assigned large subsets. The distribution of the degree of a given vertex is characterized and is shown to depend on the weight of the vertex. In particular, if the weight distribution is a power law, the degree distribution will be as well. Furthermore, an asymptotic expression for the clustering in the graph is derived. By tuning the parameters of the model, it is possible to generate a graph with arbitrary clustering, expected degree, and—in the power-law case—tail exponent.
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Almatarneh, Zeyad, Baker Akram Falah Jarah, and Mufleh Amin AL Jarrah. "The role of management accounting in the development of supply chain performance in logistics manufacturing companies." Uncertain Supply Chain Management 10, no. 1 (2022): 13–18. http://dx.doi.org/10.5267/j.uscm.2021.10.015.
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The supply chain has been a major component of competitive strategy to enhance organizational productivity and profitability, and the supply chain is a relatively new and rapidly expanding discipline that is transforming the way that manufacturing and non-manufacturing operations meet the needs of their customers. This study aims to establish the role of management accounting in the development of supply chain performance in logistics manufacturing companies. The study applies a quantitative research methodology and uses a questionnaire method to collect the data. The study sample consists of 181 respondents. This study analyzes the data using the (SPSS) program. The results reveal a statistically significant relationship at the significance level (α≤0.05) between the management accounting, including the “target cost, value chain costing and quality costing” and supply chain performance in logistics manufacturing companies.
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Ellison, Patricia H., and Claire B. Kopp. "A Note on Interdisciplinary Research in Developmental/Behavioral Pediatrics/Psychology." Pediatrics 75, no. 5 (May 1, 1985): 883–86. http://dx.doi.org/10.1542/peds.75.5.883.
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In sum, we have offered a few observations about the practice of interdisciplinary research. Now, in addition to our rather specific suggestions, we want to add a few general comments about the interactions of professionals who are actually involved in interdisciplinary research. Collaboration between physicians and psychologists can be enriching, stimulating, and rewarding. But it can also be problematic, because the former do not have much exposure to research and the latter do not have much exposure to clinical issues. Bringing these skills together may require many hours of discussion and reading each other's publications. Overall, physicians need to improve their research skills. Reading statistics texts, taking courses, handling data sets, reviewing other researchers' statistical designs are all reasonable strategies. Psychologists also need to expand their knowledge base. Reading the clinical literature is a start, but this ought to be supplemented by consistent exposure to the clinical milieu. The physician, who has access to the clinical milieu, needs to be sensitive to the question of exposure. Our final comments about collaboration are perhaps the most sensitive ones. The maintenance of a solid physician and psychologist research collaboration requires thoughtfulness, understanding, tact, and nurturance. Consider the status and responsiblities of the physician. He or she often outranks the psychologist, has access to the subject population, daily confronts ethical issues surrounding patient diagnoses, and controls communication of information to child and family. A sense of being in charge develops. Consequently, the psychologist may be perceived as being an adjunct to the research, responsible for day-to-day operations and committing ideas to paper. This is not a good formula for research. There are no easy answers for resolving these difficult interpersonal situations. Some interdisciplinary teams have found that frequent communication helps, others have turned to interinstitution collaborations, and a few have established written guidelines for almost all aspects of the research (responsibility for decision making, day-to-day operations, first authorship on articles, etc). Addressing these delicate issues in the beginning, with intermittent reexamination, will generally lead to a successful endpoint. These reflections are offered to our colleagues in the hope that interdisciplinary research will thrive and become a mainstay of both pediatrics and developmental psychology. After all, facilitating the growth of the child is a primary goal for each discipline.
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Abdulwahab, Abdulmajid Mohammed, Ainol Madziah Zubairi, Tunku Badariah Tunku Ahmad, and Mohamad Sahari Nordin. "The State of Internet-Assisted Language Learning (IALL) Knowledge among English Major Students in a Yemeni Public University." IIUM Journal of Educational Studies 8, no. 1 (October 7, 2020): 18–31. http://dx.doi.org/10.31436/ijes.v8i1.261.
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The research aimed to examine the state of Yemeni English major students’ knowledge of Internet-assisted language learning (IALL). Two types of knowledge were assessed, i.e. subjective knowledge and objective knowledge. The study also sought to examine differences in these two types of knowledge among students by gender and discipline of study, and whether subjective knowledge and objective knowledge were significantly correlated. Simple random sampling was used to select a sample of 598 English language students from education- and non-education study programs of a Yemeni public university during the 2017 academic year. Data were collected using two separate instruments: a self-developed IALL questionnaire for objective knowledge, and an adapted subjective knowledge scale. Descriptive statistics, independent-samples t-tests and bivariate correlation were carried out with SPSS software Version 24. The results show a moderate level of perceived IALL knowledge, but lower levels of actual knowledge on various aspects of IALL, particularly with respect to tools mostly used for oral language practices, such as Skype, Busuu.com, Live Mocha and SharedLingo. Gender influenced perceived knowledge – with female students reporting significantly higher knowledge levels – but not objective knowledge, while discipline of study influenced both knowledge types in favor of students pursuing non-education degree programs. A significant but inverse relationship was discovered between subjective and objective knowledge. The results emphasize the need to start focusing on adopting IALL tools by English learners in universities across Yemen. Keywords: Internet-assisted language learning, IALL tools and resources, perceived knowledge, objective knowledge, Yemeni university students
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Zou, Jingjing, Richard A. Davis, and Gennady Samorodnitsky. "EXTREME VALUE ANALYSIS WITHOUT THE LARGEST VALUES: WHAT CAN BE DONE?" Probability in the Engineering and Informational Sciences 34, no. 2 (January 30, 2019): 200–220. http://dx.doi.org/10.1017/s0269964818000542.
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AbstractIn this paper, we are concerned with the analysis of heavy-tailed data when a portion of the extreme values is unavailable. This research was motivated by an analysis of the degree distributions in a large social network. The degree distributions of such networks tend to have power law behavior in the tails. We focus on the Hill estimator, which plays a starring role in heavy-tailed modeling. The Hill estimator for these data exhibited a smooth and increasing “sample path” as a function of the number of upper order statistics used in constructing the estimator. This behavior became more apparent as we artificially removed more of the upper order statistics. Building on this observation we introduce a new version of the Hill estimator. It is a function of the number of the upper order statistics used in the estimation, but also depends on the number of unavailable extreme values. We establish functional convergence of the normalized Hill estimator to a Gaussian process. An estimation procedure is developed based on the limit theory to estimate the number of missing extremes and extreme value parameters including the tail index and the bias of Hill's estimator. We illustrate how this approach works in both simulations and real data examples.
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Kumar, Vinod, Vandana Vandana, and D. K. Batra. "Usage pattern of e-resources among management students in Nagpur, Maharashtra (India)." Electronic Library 36, no. 4 (August 6, 2018): 665–76. http://dx.doi.org/10.1108/el-04-2016-0088.
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Purpose This paper aims to investigate the usage pattern of electronic resources (e-resources) among management graduates. The respondents were asked about the types of e-resources they used, who their influencers were, their preferred place for surfing, the frequency of use, purpose for which they used e-resources, its benefits and the problems they faced while using e-resources. The findings of the study will help in enhancing the usage of e-resources among students who opt for management courses. Design/methodology/approach This descriptive research was conducted in Nagpur, Maharashtra (India). Data collected from 150 management students through purposive sampling were analyzed through descriptive statistics, and the responses were presented in tabular form. Findings The investigation reveals that students are well aware of e-resources and consider them to be very useful for their academic performance. Interestingly, students are found to be using non-paid resources more than paid ones because of a lack of search skills. Discipline-wise investigation reveals that students from the disciplines of information technology, economics and finance use e-resources more frequently than those studying subjects like marketing, operations and human resource management. Faculty and training have emerged as strong influencers that have persuaded students to use e-resources. Research limitations/implications The present study is limited to students studying management courses in Nagpur, Maharashtra (India). Originality/value This research will help institutions, librarians and publishers in gaining insight on the utilization patterns of e-resources. The uniqueness of this study lies in the fact that it has analyzed and presented the responses of management students belonging to different disciplines in management studies such as, marketing, finance, human resource management operations, economics and information technology regarding their usage patterns of e-resources.
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Puhalskii, Anatolii A., and Ward Whitt. "Functional Large Deviation Principles for Waiting and Departure Processes." Probability in the Engineering and Informational Sciences 12, no. 4 (October 1998): 479–507. http://dx.doi.org/10.1017/s0269964800005349.
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We establish functional large deviation principles (FLDPs) for waiting and departure processes in single-server queues with unlimited waiting space and the first-in first-out service discipline. We apply the extended contraction principle to show that these processes obey FLDPs in the function space D with one of the nonuniform Skorohod topologies whenever the arrival and service processes obey FLDPs and the rate function is finite for appropriate discontinuous functions. We apply our previous FLDPs for inverse processes to obtain an FLDP for the waiting times in a queue with a superposition arrival process. We obtain FLDPs for queues within acyclic networks by showing that FLDPs are inherited by processes arising from the network operations of departure, superposition, and random splitting. For this purpose, we also obtain FLDPs for split point processes. For the special cases of deterministic arrival processes and deterministic service processes, we obtain convenient explicit expressions for the rate function of the departure process, but not more generally. In general, the rate function for the departure process evidently must be calculated numerically. We also obtain an FLDP for the departure process of completed work, which has important application to the concept of effective bandwidths for admission control and capacity planning in packet communication networks.
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van der Heijden, Matthieu, Aart van Harten, and Mark Ebben. "WAITING TIMES AT PERIODICALLY SWITCHED ONE-WAY TRAFFIC LANES." Probability in the Engineering and Informational Sciences 15, no. 4 (October 2001): 495–517. http://dx.doi.org/10.1017/s0269964801154057.
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We study vehicle waiting times at a traffic lane that is shared by traffic from two directions. In contrast to crossovers, we focus on instances where the vehicle passing time of the shared infrastructure can be large. The motivation for this model arises from our research on underground transportation systems. We examine vehicle waiting times under periodic control rules (i.e., the driving direction on the infrastructure is switched between two directions according to a fixed time schedule). We analyze both symmetric and asymmetric systems (i.e., vehicle arrival rates as well as effective green and red periods may be different for both directions). In fact, we are dealing with a single server, two-queue polling system with random setup times and periodic (nonexhaustive) service discipline. We develop approximations for the mean waiting time and we show by comparison to simulation results that the accuracy is usually in the range of 1–2% for Poisson arrivals. Also, we indicate how our approximations can be generalized to compound Poisson arrivals.
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Brum, Esttefani Duarte, Gilberto Rodrigues Liska, and Alisson Darós Santos. "Test time assessment on student's performance of statistics subjects by generalized linear models." Research, Society and Development 10, no. 9 (July 21, 2021): e8310917883. http://dx.doi.org/10.33448/rsd-v10i9.17883.
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Can the time it takes a student to complete a test influence his / her performance? To answer this question, the logistic regression model was considered. In its development, evaluation was considered as a way of quantifying the performance of a student reflecting his degree of knowledge in a given content. For this we use records of the initial and final moments when developing an evaluation. The records of time spent were obtained from five different undergraduate classes, with subjects taught by the same teacher, with the same theoretical content, at the same university. The results confirm statistically that each additional minute that the student remains taking the test, implies in greater chances of obtaining good performance, as well as differences of performance between the feminine and masculine genders, although not statistically different, demonstrating that feminine students have greater chances of reaching the average. The model also confirms, according to the odds ratios that during the evaluations the students' performance decreases, having the best score in the first test. Through the references consulted, we understand that the difference in the grades of each student is influenced by several factors, the result of their own experiences.
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Boxma, O. J., J. A. Weststrate, and U. Yechiali. "A Globally Gated Polling System with Server Interruptions, and Applications to the Repairman Problem." Probability in the Engineering and Informational Sciences 7, no. 2 (April 1993): 187–208. http://dx.doi.org/10.1017/s0269964800002862.
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A repair crew is responsible for the maintenance and operation of N installations. The crew has to perform a collection of preventive maintenance tasks at the various installations. The installations may break down from time to time, generating corrective maintenance requests which have priority over the preventive maintenance tasks. We formulate and analyze this real-world problem as a single-server multi-queue polling model with Globally Gated service discipline and with server interruptions. We derive closed-form expressions for the Laplace-Stieltjes Transform and the first moment of the waiting time distributions of the preventive and corrective maintenance requests at the various installations, and obtain simple and easily implementable static and dynamic rules for optimal operation of the system. We further show that, for the socalled elevator-type polling scheme, mean waiting times of preventive maintenance jobs at all installations are equal.
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Jain, Gautam, and Karl Sigman. "Generalizing the Pollaczek-Khintchine Formula to Account for Arbitrary Work Removal." Probability in the Engineering and Informational Sciences 10, no. 4 (October 1996): 519–31. http://dx.doi.org/10.1017/s0269964800004538.
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Recently, a Pollaczek-Khintchine-like formulation for M/G/l queues with disasters has been obtained. A disaster is said to occur if a negative arrival causes all the customers (and therefore work) to depart from the system immediately. This study generalizes this result further, as it is shown to hold even when negative arrivals cause only part of the work to be demolished. In other words, an arbitrary amount of work, following a known distribution, is allowed to be removed at a negative event. Under these circumstances, a general approach for obtaining the Pollaczek–Khintchine Formula is proposed, which is then illustrated via several examples. Typically, it is seen that the formulainvolves certain parameters that are not explicitly known. The formula itself is made possible due to the number in system being geometric under preemptive last in-first out discipline.
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Lee, Chihoon, Xin Liu, Yunan Liu, and Ling Zhang. "Optimal Control of a Time-Varying Double-Ended Production Queueing Model." Stochastic Systems 11, no. 2 (June 2021): 140–73. http://dx.doi.org/10.1287/stsy.2019.0066.
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Motivated by production systems with nonstationary stochastic demand, we study a double-ended queueing model having back orders and customer abandonment. One side of our model stores back orders, and the other side represents inventory. We assume first-come-first-served instantaneous fulfillment discipline. Our goal is to determine the optimal (nonstationary) production rate over a finite time horizon to minimize the costs incurred by the system. In addition to the inventory-related (holding and perishment) and demand-related (waiting and abandonment) costs, we consider a cost that penalizes rapid fluctuations of production rates. We develop a deterministic fluid-control problem (FCP) that serves as a performance lower bound for the original queueing-control problem (QCP). We further consider a high-volume system for which an upper bound of the gap between the optimal values of the QCP and FCP is characterized and construct an asymptotically optimal production rate for the QCP, under which the FCP lower bound is achieved asymptotically. Demonstrated by numerical examples, the proposed asymptotically optimal production rate successfully captures the time variability of the nonstationary demand.
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Winands, E. M. M., I. J. B. F. Adan, G. J. van Houtum, and D. G. Down. "A STATE-DEPENDENT POLLING MODEL WITH k-LIMITED SERVICE." Probability in the Engineering and Informational Sciences 23, no. 2 (February 16, 2009): 385–408. http://dx.doi.org/10.1017/s0269964809000217.
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We consider a two-queue model with state-dependent setups, in which a single server alternately serves the two queues. The high-priority queue is served exhaustively, whereas the low-priority queue is served according to the k-limited strategy. A setup at a queue is incurred only if there are customers waiting at the polled queue. We obtain the transforms of the queue length and sojourn time distributions under the assumption of Poisson arrivals, generally distributed service times, and generally distributed setup times. The interest for this model is fueled by an application in the field of logistics. It is shown how the results of this analysis can be applied in the evaluation of a stochastic two-item single-capacity production system. From these results we can conclude that significant cost reductions are possible by bounding the production runs of the low-priority item, which indicates the potential of the k-limited service discipline as priority rule in production environments.
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Jiang, Tao. "ANALYSIS OF A CLEARING QUEUEING SYSTEM WITH SERVER MAINTENANCE AFTER N NEGATIVE FEEDBACKS." Probability in the Engineering and Informational Sciences 33, no. 2 (April 16, 2018): 220–40. http://dx.doi.org/10.1017/s026996481800013x.
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This paper is devoted to the study of a clearing queueing system with a special discipline. As soon as the server receives N negative feedbacks from customers, all present customers are forced to leave the system and the server undergoes a maintenance procedure. After an exponential maintenance time, the system resumes its service immediately. Using the matrix analytic method, we derive the steady-state distributions, which are then used for the computation of other performance measures. Furthermore, using first step analysis, we obtain the Laplace–Stieltjes transform of the sojourn time of an arbitrary customer. We also study the busy period of the system and derive the generating function of the total number of lost customers in a busy period. Finally, we investigate a long-run rate of cost and explore the optimal N value that minimizes the total cost per unit time. We also present some numerical examples to illustrate the impact of several model parameters to the performance measures.
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Bloshchynskyi, Ihor, Grygoriy Griban, Ivan Okhrimenko, Vasyl Stasiuk, Dariya Suprun, Oleh Nedvyha, Alla Neurova, et al. "Formation of Psychophysical Readiness of Cadets for Future Professional Activity." Open Sports Sciences Journal 14, no. 1 (March 22, 2021): 1–8. http://dx.doi.org/10.2174/1875399x02114010001.
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The experience of combat operations conducting in the eastern part of Ukraine in 2014-2020 convincingly demonstrated the need to increase the requirements for professional training of servicemen of the Armed Forces of Ukraine. Physical training is one of the main subjects of professional training and an important means of psychophysical readiness formation of servicemen of various military specialties for modern extreme professional and combat activities. The aim of the study is to examine the efficiency of the experimental academic program of the discipline of Physical Education, and Special Physical Training concerning the formation of psychophysical readiness of cadets of technical higher military educational institutions for future professional and combat activity. The study was conducted at S. P. Koroliov Zhytomyr Military Institute. 120 male cadets participated in the experiment. An experimental group (EG), which consisted of the cadets who were studying according to the experimental working academic program of the discipline (n=60), and a control group (CG), which included the cadets studying according to the current working academic program of the discipline (n=60) were formed. The criteria of the efficiency of the experimental program are determined to be the indicators of general and special physical fitness of cadets and the level of professionally important psychological qualities. Research methods: theoretical analysis and generalization of scientific and methodical literature, pedagogical observation, pedagogical experiment, methods of mathematical statistics. It was discovered that conducting classes according to the experimental program contributed to the improvement of the level of development of the cadets’ special physical qualities, mastering military-applied skills, the formation of professionally important psychological qualities. The most significant changes in EG cadets occurred in overcoming obstacle course, holding the angle on parallel bars, holding the body in a horizontal position, tests for determination of attention distribution and volume, mental performance – at the end of the experiment, and the indicators of EG cadets were significantly (p˂0.05-0.001) better than those of CG.It proves the necessity of correcting the academic program of Physical Education and Special Physical Training for senior cadets with the aim of their psychophysical readiness formation for future professional and combat activity.
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Mahmoud, Hosam M. "SOME NODE DEGREE PROPERTIES OF SERIES–PARALLEL GRAPHS EVOLVING UNDER A STOCHASTIC GROWTH MODEL." Probability in the Engineering and Informational Sciences 27, no. 3 (March 28, 2013): 297–307. http://dx.doi.org/10.1017/s026996481300003x.
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We introduce a natural growth model for directed series-parallel (SP) graphs and look at some of the graph properties under this stochastic model. Specifically, we look at the degrees of certain types of nodes in the random SP graph. We examine the degree of a pole and will find its exact distribution, given by a probability formula with alternating signs. We also prove that, for a fixed value s, the number of nodes of outdegree 1, …, s asymptotically has a joint multivariate normal distribution. Pólya urns will systematically provide a working tool.
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Gambier, Adrian. "Multiobjective Optimal Control of Wind Turbines: A Survey on Methods and Recommendations for the Implementation." Energies 15, no. 2 (January 13, 2022): 567. http://dx.doi.org/10.3390/en15020567.
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Advanced control system design for large wind turbines is becoming increasingly complex, and high-level optimization techniques are receiving particular attention as an instrument to fulfil this significant degree of design requirements. Multiobjective optimal (MOO) control, in particular, is today a popular methodology for achieving a control system that conciliates multiple design objectives that may typically be incompatible. Multiobjective optimization was a matter of theoretical study for a long time, particularly in the areas of game theory and operations research. Nevertheless, the discipline experienced remarkable progress and multiple advances over the last two decades. Thus, many high-complexity optimization algorithms are currently accessible to address current control problems in systems engineering. On the other hand, utilizing such methods is not straightforward and requires a long period of trying and searching for, among other aspects, start parameters, adequate objective functions, and the best optimization algorithm for the problem. Hence, the primary intention of this work is to investigate old and new MOO methods from the application perspective for the purpose of control system design, offering practical experience, some open topics, and design hints. A very challenging problem in the system engineering application of power systems is to dominate the dynamic behavior of very large wind turbines. For this reason, it is used as a numeric case study to complete the presentation of the paper.
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Otheitis, Nikolaos, and Martin Kunc. "Performance measurement adoption and business performance." Management Decision 53, no. 1 (February 9, 2015): 139–59. http://dx.doi.org/10.1108/md-02-2014-0108.
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Purpose – Seaborne trade accounts for 90 per cent of world’s total trade activity. Ship management is a highly skilled discipline with a high degree of complexity yet it has failed to follow with the same pace the advancements of performance measurement systems (PMSs) like other industries. Business performance measurement has only recently become a relevant topic in shipping. The purpose of this paper is to evaluate the adoption of PMS in the shipping industry. Design/methodology/approach – A questionnaire was developed based on the performance measurement literature and submitted to 100 shipping companies around the world obtaining 41 usable questionnaires covering 13 countries from Europe, Asia and America. Findings – The adoption of performance measurement differs based on type of business: liquid bulk (tanker) vessels and bulk carriers or containers. Quality and safety management systems have fostered the adoption of performance measurement positively in tankers impacting decision making and the performance of shipping companies using PMS. Research limitations/implications – While the sample is representative of the situation of the industry, it represents the results of one point in time. Practical implications – The use of PMSs can be a tool to achieve superior performance but it may be fostered by, and has to be aligned with the needs of, internal and external stakeholders. Early adopters in the shipping industry are among the leaders in the industry. Originality/value – The paper is a unique contribution to performance measurement since it explores the adoption of PMSs and its impact in performance at industry level in a global industry.
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Gubina, L. V., T. V. Alekseeva, and O. A. Strakhov. "Analysis of some factors influencing the performance of college students: An example of Computer Science education." Education and science journal 22, no. 2 (March 4, 2020): 171–96. http://dx.doi.org/10.17853/1994-5639-2020-2-171-196.
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Introduction. In recent years, the structure and content of training of specialists of further education have significantly improved. The increased popularity of the secondary vocational education system is evidenced by the fact that more than half of the Russian teenagers after graduating from the main stage of secondary school become applicants of technical schools and colleges. In order to manage students’ education more effectively, among other measures, it is necessary to diagnose the motivation of enrolled students at the stage of admission to the educational institution and to identify the degree of awareness of their future career choice, as these factors directly depend on the success of educational programmes.The aim of the article was to reveal the trends of influence of students’ results at the Basic State Exam (OGE – the exam, which is taken when finishing education in the 9th (final) form of comprehensive school) on the level of knowledge of Computer Science in colleges and to find out the subjective reasons of students’ preferences for the secondary vocational education system to continue studies and to enter a profession.Methodology and research methods. In the course of the study, a review and generalisation of the content of scientific sources related to the problems of professional choice and training motivation were used. Diagnostics of motivation of college students in Moscow, Moscow region and the regions of Russia was conducted through the methods of testing, surveys and anonymous questioning. Processing of the obtained data was carried out by the methods of correlation, variance and regression analysis; the degree of statistical reliability of the results was evaluated by calculating the Student’s t-test and the Fisher’s F-test.Results and scientific novelty. The authors have calculated the numerical indicators of relationship between students’ academic performance in computer science and the Basic State Exam taking, the reasons for choosing the secondary vocational education and the specialty. Constructed graphs and approximating curves prove the fact that the success degree when learning the certain discipline in college results from the assessment within the discipline taken at the Basic State Exam in school. In the regions of Russia, this factor guarantees a higher level of knowledge on Computer Science – by about 20%, and in the Moscow region – by 10%. The statistics on respondents’ professional orientation were collected. A regression model, demonstrating the impact of students’ motivational attitudes on their training in the subject discipline, is presented. It was found out that the motives “subsequent admission to a specialised university”, “obtaining a profession”, “business attitude to a profession” and “prestige of a profession” have the most positive influence in this context. The variance analysis confirmed the determinism of the learning outcomes by the reasons for the choice of secondary vocational education and profession. It is concluded that the reasons for the low or medium students’ performance include not only their weak motivation for education, but also the state of the entire education system, including the institutions of the Basic State Exam (OGE) and the Unified State Exam (EGE – high school final and university entrance exam taken upon completion of the 11th form), as well as the lack of clear criteria for the admission of applicants to the institutions of secondary vocational education. To get a specific specialty, the desire to study, its informed choice and prestige of profession positively affect students’ learning outcomes in Computer Science education.Practical significance. The research materials can be useful for teachers of secondary vocational education and for specialists involved in career guidance.
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Wicaksono, Fermi Dwi, Udisubakti Ciptomulyono, Ketut Buda Artana, and Mohammad Isa Irawan. "STATISTICAL ANALYSIS OF THE HIGH POTENTIAL INCIDENT IN ANDALS OIL OF INDONESIA." Jurnal Teknologi 83, no. 2 (February 2, 2021): 1–13. http://dx.doi.org/10.11113/jurnalteknologi.v83.14884.
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The oil and gas industry involves latent risks which are considered as one of the most severe consequences. This circumstance mainly due to the existence of intrinsic hazards involved. As part of process safety management, past incidents analysis should be performed to eliminate the potential of significant accident occurrence. It is crucial to identify the root cause of the incidents. This research discloses the degree of importance of causal factors in contributing to an incident. The methodology based on regression analysis and path analysis is performed to identify the degree of importance of incident causes. A case study is performed at Andals Oil of Indonesia to demonstrate the most significant factor leading to an incident. As the baseline for this research, incident data are gathered from Andals Oil's database during 2006 – 2018. The statistics describe the most frequent type of incident that occurs during the oil and gas field operations. Three major root causes in the oil and gas industry are evaluated: 1. Organizational system factor; 2. Job factor leading to unsafe working conditions; 3. Human-behavioral factor. Based on the regression analysis and path analysis, it is concluded that the number of High potential incidents is directly affected by Job factor leading to unsafe condition and Human-behavioral factor. Although the Organizational system factor may not significantly affect the number of High potential incidents, this factor still directly engenders unsafe working condition by affecting variable Job factors.
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Chaudhry, Mohan L., Dae W. Choi, and Kyung C. Chae. "COMPUTATIONAL ANALYSIS OF STATIONARY WAITING-TIME DISTRIBUTIONS OF GIX/R/1 AND GIX/D/1 QUEUES." Probability in the Engineering and Informational Sciences 19, no. 1 (January 2005): 121–40. http://dx.doi.org/10.1017/s0269964805050084.
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In this article, we obtain, in a unified way, a closed-form analytic expression, in terms of roots of the so-called characteristic equation of the stationary waiting-time distribution for the GIX/R/1 queue, where R denotes the class of distributions whose Laplace–Stieltjes transforms are rational functions (ratios of a polynomial of degree at most n to a polynomial of degree n). The analysis is not restricted to generalized distributions with phases such as Coxian-n (Cn) but also covers nonphase-type distributions such as deterministic (D). In the latter case, we get approximate results. Numerical results are presented only for (1) the first two moments of waiting time and (2) the probability that waiting time is zero. It is expected that the results obtained from the present study should prove to be useful not only for practitioners but also for queuing theorists who would like to test the accuracies of inequalities, bounds, or approximations.
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Zartha Sossa, Jhon Wilder, William Halal, and Raul Hernandez Zarta. "Delphi method: analysis of rounds, stakeholder and statistical indicators." foresight 21, no. 5 (September 10, 2019): 525–44. http://dx.doi.org/10.1108/fs-11-2018-0095.
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Purpose The purpose of this study is to review the literature on the Delphi method, its characteristics and current applications through an analysis of recent most-cited scientific papers, with an emphasis on three axes, namely, the number of rounds used, stakeholder participation relevance or only academic experts’ participation and the possibility of using indicators or techniques different from those related to descriptive statistics. Design/methodology/approach In total, 57 papers were initially reviewed, 10 of them with a high citation rate. Then, an analysis was made of papers in Scopus for the period 2015-2018 published in the Technological Forecasting and Social Change Journal and in the Futures and Foresight Journal, which had the characteristic of displaying quartile Q1 or Q2 in Scimago in addition to being in Scopus. Findings Among the main results, the authors observe the tendency to use fewer rounds, a higher prevalence of stakeholder participation and not only academic experts but also the use of new types of modified Delphi such as real-time spatial Delphi, Delphi group, market Delphi, real-world Delphi and policy Delphi. Originality/value Among the conclusions, the possibility of using other indicators or complementary techniques to the descriptive statistics is highlighted such as number of justifications or comments between rounds, coefficients to quantify the competence or degree of expertise of the participants, measures of the perception of the expert on the usefulness of the presented feedback, graphs of the number of arguments according to the number of questions, the Wilcoxon Ranked Pairs Test, the k means, Kolmogorov–Simonov test and the Mann–Whitney U-test.
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Pinto, Maria, Cristina Pouliot, and José Antonio Cordón-García. "E-book reading among Spanish university students." Electronic Library 32, no. 4 (July 29, 2014): 473–92. http://dx.doi.org/10.1108/el-05-2012-0048.
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Purpose – This paper aims to show data about Spanish higher-education students’ usage, habits and perceptions regarding reading on new digital media to show the potential future of electronic books (e-books) and reading mobile devices (e-readers, tablets, cell phones, etc) in academia. It explores whether demographics and academic factors might influence e-book reading habits and attitudes and university students’ opinions about e-books vs print books. REWIL 2.0, a purpose-built research tool, was applied to measure students’ opinions about digital reading in different media and formats, considering their academic context, at the confluence of analog and digital materials and learning. Likewise, REWIL 2.0 detects who are e-book readers (eBR) and who are not and produces a statistics indicator to identify five categories of eBRs by their frequency of e-book reading. This research gathered 745 online surveys between April and July 2010 in 15 degree programs at the University of Granada: Spanish philology, English philology, history, mathematics, chemistry, environmental sciences, education, library and information science, law, medicine, biology, dentistry, computer systems, architecture and civil engineering. Design/methodology/approach – This present study is a transversal applied research, where 745 students were surveyed from 15 different academic disciplines offered at the University of Granada (Spain), representing the five main discipline areas. The survey was carried out by means of a structured online survey, with REWIL 2.0 research tool. To ensure internal consistency of correlation between two different survey items designed to measure e-book reading frequency, Pearson’s r reliability test was applied. Likewise, Persons’ chi-squared statistics were applied to test the hypotheses and to detect if significant correlation existed between academic disciplines and e-book reading frequency measured through a Likert scale. Findings – The present research is motivated by our interest in discovering what effect the current technological maelstrom and the rapid growth of new portable digital reading devices in the Spanish university environment are having on students’ lives, and the extent to which students have adopted new reading technologies. Their first aim is to establish who is reading e-books in the University? A second aim is to answer the following question: is the academic discipline a determinant factor in e-book reading habits and students’ attitudes about it? The authors began by considering the following hypotheses: University students’ attitudes to e-book reading and the way they use them will be determined by the scientific discipline they study. Students of humanities, social sciences and law will prefer to read traditional format books (printed paper), while students of experimental sciences, health and technical courses will prefer reading e-books. Students’ preferences will be determined by their previous reading experiences. Originality/value – The main objective of the present study is to learn whether there are any notable differences among university students from distinct disciplines with regard to their attitude and behavior toward e-books. The authors, therefore, set out to identify the segment of the student population that does not read e-books yet (non-eBRs) from those who have already read at least one (eBRs), and within this segment, the readers that have read e-books recently (recent eBRs); find out how frequently university students are reading in different formats (paper and digital), document types (book, written press, etc.) and languages (textual, multimodal, etc.) identify what channels are used to access e-books; find out university students’ opinions on the advantages and disadvantages of reading e-books as compared to traditional print books; and identify the types of improvements or changes to the design–production–distribution–reception chain that students consider might help extend e-book reading.