Unforeseeable Factors Research Articles

Optimization of the operations and maintenancefor wind farm using genetic algorithms

In Morocco, with the growing wind installed capacity it becomes crucial to perform further the O&M process, the wind assets are exposed to several constraints and raindom of maintenances for incidents. The target of this work is to optimize the gross and net production while simultaneously adhering to the minimum turbine unavailability and minimizing all contractual power curtailments due to unforeseeable factors. The proposed system is modeled using technical and mathematical formulas composed of the main function and the associated constraints. The project's modularization ends with a complex mathematical system that is non-linear, non-differentiable and requires the genetic algorithm for optimal resolution. Using Matlab to determine the optimized solution that represents the number of operational turbines per day, allowing for maximum production, minimizing curtailment, and reducing the unavailability of turbines. The 365-vector containing the numbers of turbines per day will opimally define the long-term O&M strategy.

Failure analysis of stainless and heat resisting steels, documented on selected examples

Abstract Failures of stainless and heat-resistant austenitic CrNi steels frequently occur in practice due to incorrect material selection, improper processing or unforeseeable factors under operating conditions. Selected examples will be used to illustrate various of these factors influencing the development of failure.

Japhetic grammatology

Nikolai Marr has attracted scholarly attention, but largely in a cautionary manner. His work is read as an ideological incursion into the science of language. More charitable assessments contextualize him within oriental studies in the Russian Empire and, in turn, early Soviet nationality policy. Yet ever since his fall from official favour in 1950, scholars have been reluctant to assess his scholarly contributions on their own merit. This essay is an attempt to reconsider Marr by historicizing the mainstream school of thought against which he is compared and found wanting. The pivotal figure for linguistics as we know it today was Ferdinand de Saussure, whose rigorous separation of the systematic synchronic moment of language from its protean historical existence solved a problem which had confounded his contemporaries. It made it possible to treat language as systematic from moment to moment, despite being subject to unforeseeable factors when viewed through time. In drawing this distinction Saussure fatefully privileged speech over writing as the truest instantiation of language. This allowed existing scientific-racist assumptions about the determining influence of anatomy on speech to remain unchallenged. Marr’s early career paralleled that of Saussure’s, yet when it came to the philosophy of language he started from very different premises. Marr identified the origin of language with gesture and tool use. His understanding of evolution departed radically from the organicism common to his contemporaries. Marr’s empirical statements about language are fanciful and cannot easily be recuperated. However, his work represents a tantalizing path not taken in the history of linguistics. As such it is worth reading Marr in the light of Derrida’s reading of Saussure. By bringing Marr into dialogue with better-known thinkers, and historicizing Derrida’s inaugural act of deconstruction, we can sketch the contours of a counter-tradition in linguistics.

Multi-machine preventive maintenance scheduling with imperfect interventions: A restless bandit approach

In this paper we address the problem of allocating the efforts of a collection of repairmen to a number of deteriorating machines in order to reduce operation costs and to mitigate the cost (and likelihood) of unexpected failures. Notwithstanding these preventive maintenance interventions are aimed at returning the machine to a so-called as-good-as-new state, unforeseeable factors may imply that maintenance interventions are not perfect and the machine is only returned to an earlier (uncertain) state of wear. The problem is modelled as a restless bandit problem and an index policy for the sequential allocation of maintenance tasks is proposed. A series of numerical experiments shows the strong performance of the proposed policy. Moreover, the methodology is of interest in the general context of dynamic resource allocation and restless bandit problems, as well as being useful in the particular imperfect maintenance model described.

İNŞAAT İŞLERİNİN İŞ PROGRAMINA BAĞLI NAKİT AKIŞI DEĞİŞKENLİĞİNİN SAPTANMASI VE DÜZENLENMESİ

İnşaat projesinin yapım süresi ve maliyeti inşaat öncesinde hazırlanan malzeme tedariki ve metraj verilerine dayanarak oluşturulan iş programı ve maliyet analizleri temel alınarak tahmin edilir. İnşaat sürecinde öngörülemeyen etkenler nedeniyle iş programında ve maliyetlerde değişiklikler meydana gelebilir. Bu durum, nakit akışını etkiler. İnşaat sırasındaki iş yoğunluğu nedeniyle nakit akışının güncellemesinin ihmali, gelir gider dengesinin önceden bilinememesine neden olacak ve inşaatın finansmanı üzerinde önemli sorunlar doğurabilecektir. Bu çalışmada, belirtilen sorunların oluşmaması ve güncel verileri kullanarak en doğru ve güncel nakit akışı elde etmek için hakediş hesaplamalarını doğrudan iş programı ile ilişkilendirerek hesaplayan bir model geliştirilmiştir. Bunun için tüm metraj hesaplarında işlem adımları formülleştirilmiş ve formüller hesap cetveli uygulamasında tanımlanmıştır. Malzeme tedariki dâhil metraj verileri ile iş kalemlerinin işçilik ihtiyaçları ve süreleri belirlenmiştir. Doğrusal iş programı ile oluşturulan iş planından aktivitelerin başlangıç ve bitiş süreleri elde edilmiştir. Aktivitelerin maliyetleri birim fiyat analizleri ile belirlenmiş ve günlük gerçekleşen inşaat işleri ve harcamaları hesaplanmıştır. Aktivite sürelerinde olabilecek değişiklikler, iş programı ile birlikte güncellenmekte ve insan müdahalesi olmadan gerçekleşen kısma ait hak ediş ve kalan imalat bedeli yeniden hesaplanmaktadır. Hesaplamaların, tüm müteahhitlerin uygulayabileceği biçimde gösterilebilmesi için hesap cetveli uygulaması şeklinde tasarlanmıştır. Bu uygulama sayesinde müteahhitler inşaat işlerinin nakit akışını anlık güncelleyebilecek ve ileride oluşabilecek olumsuzlukları önceden fark edip önlem alabileceklerdir.

Out-migration in Rural Pakistan: Does Household Poverty Status Matter?

Movement of the people within the geographical and administrative boundaries of a country is known as internal migration. Researchers regard the movement to urban areas from both rural and less-advanced urban areas as more important, yet studying the dimensions of movement between rural areas is worth investigating. Scholars assert economic incentives as the main motive behind the rural-urban movement; various unforeseeable factors, however, may also stimulate the human flows. In Pakistan, the phenomenon of internal migration is as old as the inception of the country as Helbock (1975a) maintained, while studying life-time migrants in 12 largest cities of the country in 1961, that almost every 7th person residing in these cities had come from a different district

The Art Of Interpretation – Chances And Risks On Interpretation In The Field Of Mobile Testing

Abstract Carrying out a usability test is a demanding process per se. Mobile tests raise this claim because they are subject to real usage conditions and therefore unforeseeable factors. On the one hand there are the technical factors like tools, software and laboratory equipment, but on the other hand there are the human beeings with their knowledge and decision-making. They are taking the selection of tools, methods and data, and they decide in every situation of the process of testing. Using a mobile eye-tracking test, the authors will explain where the sources for interpretation are and when misinterpretation become an error. Technology philosophical considerations on interpretation and hermeneutics have to support the recognition of the potential of interpretation. As a result, misinterpretation can be minimized.

Scenario Analysis of Regional Electricity Demand in the Residential and Commercial Sectors – influence of Diffusion of Photovoltaic Systems and Electric Vehicles into Power Grids

Recent years, various new energy products, such as photovoltaic (PV) systems and electric vehicles (EVs), have been diffused. While the diffusion of such products will affect the electricity demand of power grids, it is difficult to predict to what extent those products will be diffused in our society because the diffusion of such products depends on various unforeseeable factors such as energy policies. To analyze the influence of the diffusion of such products upon electricity demand, this paper describes several scenarios of future regional power grids. We focus on residential and commercial sectors because the end-use energy consumption in these sectors is, at least in Japan, increasing and it thus needs to be reduced. In the case study, we described scenarios in Toyonaka City, Osaka Prefecture, Japan. The results revealed that the total electricity demand in the residential and commercial sectors decreases 10.5% from 2012 to 2030 with population decrease. The diffusion of PV decreases the total electrical load of the grid by 19.7%. Moreover, EV diffusion has the potential to reduce the peak of electrical load by 37.3% by using batteries of EVs.

Secondary Evacuation Systems for Skyscrapers: Post 9/11 Tall Building Safety Research

Skyscrapers are playing a more and more important role in modern life and definitely more and more tall buildings will be built in the future. But at the same time they are facing more threats from terrorists, fire, earthquake and other unforeseeable factors than before. This paper presents the idea of providing a secondary evacuation system in tall buildings, as a supplement to the existing primary means of evacuation especially when they are damaged or unusable in an extreme event. It illustrates the design flaws inherent in high-rise buildings today and the inadequacy of their primary evacuation systems and introduces some new mechanisms currently used as a secondary evacuation system. The paper thus serves as an introduction to this area and produces some useful advice for increasing the safety of tall buildings.

Predicting Sleep/Wake Behavior for Model-Based Fatigue Risk Management

Predicting Sleep/Wake Behavior for Model-Based Fatigue Risk Management

Selectionism and Learning in Projects with Complexity and Unforeseeable Uncertainty

Companies innovating in dynamic environments face the combined challenge of unforeseeable uncertainty (the inability to recognize the relevant influence variables and their functional relationships; thus, events and actions cannot be planned ahead of time) and high complexity (large number of variables and interactions; this leads to difficulty in assessing optimal actions beforehand).There are two fundamental strategies to manage innovation with unforeseeable uncertainty and complexity: trial and error learning and selectionism. Trial and error learning involves a flexible (unplanned) adjustment of the considered actions and targets to new information about the relevant environment as it emerges. Selectionism involves pursuing several approaches independently of one another and picking the best one ex post.Neither strategy nor project management literatures have compared the relative advantages of the two approaches in the presence of unforeseeable uncertainty and complexity. We build a model of a complex project with unforeseeable uncertainty, simulating problem solving as a local search on a rugged landscape. We compare the project payoff performance under trial and error learning and selectionism, based on a priori identifiable project characteristics: whether unforeseeable uncertainty is present, how high the complexity is, and how much trial and error learning and parallel trials cost. We find that if unforeseeable uncertainty is present and the team cannot run trials in a realistic user environment (indicating the project's true market performance), trial and error learning is preferred over selectionism. Moreover, the presence of unforeseeable uncertainty can reverse an established result from computational optimization: Without unforeseeable uncertainty, the optimal number of parallel trials increases in complexity. But with unforeseeable uncertainty, the optimal number of trials might decrease because the unforeseeable factors make the trials less and less informative as complexity grows.

The Oracle, the Ordeal and the Bet

Any classification of games, no matter how determined and what principle of division is chosen, reveals an irreducible category: games of chance. This does not mean that this category is destitute of ambiguity. Because, after all, is it sufficient for chance to play a part in such recreational activity and thus transform it into a game of chance? We can investigate the nature of chance, the part it must play and the extent of its role. It is rather clear that in many games one can discern an element of chance, without this being enough to define these games as games of chance. The chess-player who develops a system of attack cannot take into account all the possibilities of his antagonist's reply. He is naturally inclined to speculate on a partially fortuitous future and to rely on a certain amount of “good luck: “ si fortuna iuvat. We have chosen a rather paradoxical example, since in such competition the best calculator is theoretically sure of winning or of stalemating. But in all human occupations, and therefore a fortiori in recreational activities, the indetermination of the future plays a role which can be lessened but not reduced to nothing. From this point of view, what game is not a game of “chance?” Without what sport commentators call “the glorious uncertainty of sport” which is simply the global name for a vertiginous number of unforeseeable factors, determined beyond doubt, but indeterminable in their totality, and so foreign one to another that they cannot be “integrated,” a match of rugby or tennis would have no spectacular interest. It would be the equivalent of an experimental verification.