Life-cycle of fatigue sensitive structures under uncertainty

Fatigue is the one of the main contributors to problems related to structural safety of civil and marine structures. Life-cycle management (LCM) techniques considering various uncertainties can be used to predict the safe service life of fatigue sensitive structures, plan for their future inspections and support the decision making process regarding maintenance and repair actions. This paper provides a brief overview of the LCM of fatigue sensitive civil and marine structures under uncertainty. Probabilistic performance prediction, inspection scheduling and maintenance optimization for such structures are discussed

Solar cycle 25: another moderate cycle?

Surface flux transport simulations for the descending phase of cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipole moment around 2020 $(2.5\pm1.1\,$G) is comparable to that observed at the end of cycle 23 (about $2\,$G). The empirical correlation between the dipole moment during solar minimum and the strength of the subsequent cycle thus suggests that cycle 25 will be of moderate amplitude, not much higher than that of the current cycle. However, the intrinsic uncertainty of such predictions resulting from the random scatter of the source properties is considerable and fundamentally limits the reliability with which such predictions can be made before activity minimum is reached.Comment: 13 papges, 4 figures,Accepted for publication in ApJ

Life cycle analysis of road construction and use

Both the construction and use of roads have a range of environmental impacts; therefore, it is important to assess the sources of their burdens to adopt correct mitigation policies. Life cycle analysis (LCA) is a useful method to obtain demonstrable, accurate and non-misleading information for decision-making experts. The study presents a "cradle to gate with options" LCA of a provincial road during 60 year-service life. Input data derive from the bill of quantity of the project and their impacts have been evaluated according to the European standard EN 15804. The study considers the impacts of the construction and maintenance stages, lighting, and use of the vehicles on the built road. The results obtained from a SimaPro model highlight that the almost half of impacts took place during the construction stage rather than the use stage. Therefore, the adoption of environmentally friendly road planning procedures, the use of low-impact procedures in the production of materials, and the use of secondary raw materials could have the largest potential for reducing environmental impacts

Cycle structure of random permutations with cycle weights

We investigate the typical cycle lengths, the total number of cycles, and the number of finite cycles in random permutations whose probability involves cycle weights. Typical cycle lengths and total number of cycles depend strongly on the parameters, while the distributions of finite cycles are usually independent Poisson random variables.Comment: 22 pages, 2 figure

Measuring the Welfare Costs of Inflation in a Life-cycle Model

In macroeconomics, life-cycle models are typically used to address exclusively life-cycle issues. This paper shows that modeling the life-cycle may be important when addressing public policy issues, in this case the welfare costs of inflation. In the representative agent model, the optimal inflation rate is characterized by the Friedman rule: deflate at the real interest rate. In the corresponding life-cycle model, the optimal inflation rate is quite high: for the benchmark calibration, it is around 95% per annum. Much of the paper is concerned with understanding this result. Briefly, in the life-cycle model there are distributional consequences of injecting money via lump-sum transfers. The net effect is to transfer income from old, rich agents to young, poor ones. These transfers twist the age-utility profile in a way that agents find desirable from a lifetime utility point of view. A second issue concerns how to assess the costs of inflation in a life-cycle model. Metrics that are equivalent in the representative agent model can give very different answers in a life-cycle model.monetary policy, inflation, welfare costs, life-cycle model

Rooted Cycle Bases

A cycle basis in an undirected graph is a minimal set of simple cycles whose symmetric differences include all Eulerian subgraphs of the given graph. We define a rooted cycle basis to be a cycle basis in which all cycles contain a specified root edge, and we investigate the algorithmic problem of constructing rooted cycle bases. We show that a given graph has a rooted cycle basis if and only if the root edge belongs to its 2-core and the 2-core is 2-vertex-connected, and that constructing such a basis can be performed efficiently. We show that in an unweighted or positively weighted graph, it is possible to find the minimum weight rooted cycle basis in polynomial time. Additionally, we show that it is NP-complete to find a fundamental rooted cycle basis (a rooted cycle basis in which each cycle is formed by combining paths in a fixed spanning tree with a single additional edge) but that the problem can be solved by a fixed-parameter-tractable algorithm when parameterized by clique-width.Comment: 12 pages with 10 additional pages of appendices and 10 figures. Extended version of a paper to appear at the 14th Algorithms and Data Structures Symposium (WADS), Victoria, BC, August 201

THE DEVELOPMENT OF SOFT SKILL ASPECT THROUGH COOPERATIVE LEARNING STRATEGY ON ELECTRONIC CIRCUIT LESSON FOR THE XIITH GRADE STUDENT AT DEPONTMENT OF AUDIO-VIDEO ENGINEERING IN SMK N 2 KLATEN

This research is development or increase of soft skills for student with cooperative learning strategy so that development process of soft skills can do in the study classroom, for example commitment, responsibility, cooperate, creativity and ethics. Beside that for knowing, what of soft skills with cooperative learning strategy can increase of soft skills for student compare with conventional method or discourse method in the study classroom can be doing by student XIIth class of 2 Klaten vocational high school. This research is Classroom Action Research execute at 2 Klaten vocational High school. Every cycle begin from planning, action, observation and reflection. Data analyst is doing to compare between the observation result of cycle I, Cycle II, and cycle III with qualitative description method which to clear with the mean of percent of soft skills who have a student. The result of the research is cooperative learning can be development of soft skills for student on commitment aspect, responsibility, cooperate, creativity and ethics with step that is group discussion and practice. The mean of soft skills who have student base observation at cycle I are 53,20 % (enough), Cycle II are 61,20 % (high) and cycle III are 64,80 % (high). While the observation result in soft skills aspect, is commitment aspect beginning at cycle I are 52 % (enough), cycle II are 63 % (high) and cycle III are 66 % (high). In the responsibility aspect beginning at cycle I are 53 % (enough), cycle II are 59 % (enough) and cycle III are 60 % (high), in the cooperate aspect beginning at cycle I are 55 % (enough), cycle II are 70 % (high) and cycle III are 71 % (high), in the creativity aspect beginning at cycle I are 53 % (enough), cycle II are 59 % (enough) and cycle III are 63 % (high), and in the ethics aspect beginning at cycle I are 53 % (enough), cycle II are 55 % (enough) and cycle III are 62 % (high), from of all observation result above, so can be said in general soft skills for student experiencing development with using cooperative learning strategy in the study classroom. Keyword : Cooperative Learning, soft skills, commitment, responsibility, cooperate, creativity and ethic