75,351 research outputs found

    Pemanfaatan Tras dari Samigaluh Kulon Progo sebagai Bahan Pozolan untuk Campuran Mortar

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    Cement is one of mortar components with significant influence to mortar quality and production cost. It is necessary to use alternative material as cement substitution material to reduce production cost without reducing the mortar quality. One of materials used as cement substitution is pozzolan. One type of pozzolan is Trass which is available in Kulon Progo Regency but has not been utilized optimally. The objective of this research is to obtain the mix ratio of lime-trass used as cement substitution in mortar production. This research used sand from Boyong, lime from Gunung Kidul, and trass from Samigaluh Kulon Progo. The chemical composition consised of active silica and trass petrography was used as secondary data. The primary data was the experiment result carried out in Construction Material Laboratory of Gadjah Mada University. The first step of experiment was to identify the mortar material characteristics. Then a paste mix in 4 ratios variation of mix lime-trasss (1:4, 2:3, 3:2, and 4:1) was made. Lime – trass mix ratio that produced the highest compression strength mortar (through compression test after 7 days) was used as cement substitution. Mortar mix ratio of cement (and cement substitution) and sand was 1 : 4. The Variations of cement : lime-trass were 1:0,1:4, 2:3, 3:2, 4:1, and 0:1. Result of the research showed that paste mix ratio of lime and trass of 2: 3 had the highest compression strength, which was used in the mortar mixes design. Results of mortar compression strength testing showed that the lower the compression strength, the larger the amount of the cement substitution. The mix of lime and trass taken from Pagerharjo can be used as cement substitution material for producing mortar type S to type O or concrete brick quality I to quality IV. Mix of lime and trass taken from Purwoharjo can be used as cement substitution material for producing mortar type N to type O or concrete brick quality I to quality III. Mortar tensile strength testing showed that the lower the tensile strength, the larger the cement substitution amount was. On the other hand, the larger the mortar permeability, the larger cement substitution amount was. Cement substitution can reduce the cement amount in mortar production but increase mortar production cost because trass production cost was more expensive than cement price

    An experimental study of the dual-fuel performance of a small compression ignition diesel engine operating with three gaseous fuels

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    A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine

    Education, growth and income inequality

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    Estimates of the e¤ect of education on GDP (the social return to education)have been hard to reconcile with micro evidence on the private return. We present a simple explanation that combines two ideas: imperfect substitution between worker types and endogenous skill biased technological progress. When types of workers are imperfect substitutes, the supply of human capital is negatively related to its return, and a higher education level compresses wage di¤erentials. We use cross-country panel data on income inequality to estimate the private return and GDP data to estimate the social return. The results show that the private return falls by 2 percentage points when the average education level increases by a year, which is consistent with Katz and Murphy's [1992] estimate of the elasticity of substitution between worker types. We find no evidence for dynamics in the private return, and certainly not for a reversal of the negative e¤ect as described in Acemoglu [2002]. The short run social return equals the private return.Growth, inequality, education, private and social return to schooling, compression effect

    Reducing the loss of information through annealing text distortion

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    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Granados, A. ;Cebrian, M. ; Camacho, D. ; de Borja Rodriguez, F. "Reducing the Loss of Information through Annealing Text Distortion". IEEE Transactions on Knowledge and Data Engineering, vol. 23, no. 7 pp. 1090 - 1102, July 2011Compression distances have been widely used in knowledge discovery and data mining. They are parameter-free, widely applicable, and very effective in several domains. However, little has been done to interpret their results or to explain their behavior. In this paper, we take a step toward understanding compression distances by performing an experimental evaluation of the impact of several kinds of information distortion on compression-based text clustering. We show how progressively removing words in such a way that the complexity of a document is slowly reduced helps the compression-based text clustering and improves its accuracy. In fact, we show how the nondistorted text clustering can be improved by means of annealing text distortion. The experimental results shown in this paper are consistent using different data sets, and different compression algorithms belonging to the most important compression families: Lempel-Ziv, Statistical and Block-Sorting.This work was supported by the Spanish Ministry of Education and Science under TIN2010-19872 and TIN2010-19607 projects

    Sequence alignment, mutual information, and dissimilarity measures for constructing phylogenies

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    Existing sequence alignment algorithms use heuristic scoring schemes which cannot be used as objective distance metrics. Therefore one relies on measures like the p- or log-det distances, or makes explicit, and often simplistic, assumptions about sequence evolution. Information theory provides an alternative, in the form of mutual information (MI) which is, in principle, an objective and model independent similarity measure. MI can be estimated by concatenating and zipping sequences, yielding thereby the "normalized compression distance". So far this has produced promising results, but with uncontrolled errors. We describe a simple approach to get robust estimates of MI from global pairwise alignments. Using standard alignment algorithms, this gives for animal mitochondrial DNA estimates that are strikingly close to estimates obtained from the alignment free methods mentioned above. Our main result uses algorithmic (Kolmogorov) information theory, but we show that similar results can also be obtained from Shannon theory. Due to the fact that it is not additive, normalized compression distance is not an optimal metric for phylogenetics, but we propose a simple modification that overcomes the issue of additivity. We test several versions of our MI based distance measures on a large number of randomly chosen quartets and demonstrate that they all perform better than traditional measures like the Kimura or log-det (resp. paralinear) distances. Even a simplified version based on single letter Shannon entropies, which can be easily incorporated in existing software packages, gave superior results throughout the entire animal kingdom. But we see the main virtue of our approach in a more general way. For example, it can also help to judge the relative merits of different alignment algorithms, by estimating the significance of specific alignments.Comment: 19 pages + 16 pages of supplementary materia

    Non Sequential Recursive Pair Substitution: Some Rigorous Results

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    We present rigorous results on some open questions on NSRPS, non sequential recursive pairs substitution method (see Grassberger in \cite{G}). In particular, starting from the action of NSRPS on finite strings we define a corresponding natural action on measures and we prove that the iterated measure becomes asymptotically Markov. This certify the effectiveness of NSRPS as a tool for data compression and entropy estimation.Comment: 20 page
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