875 research outputs found
Perbandingan Hasil Belajar Siswa Menggunakan Media Permainan Ular Tangga Dengan Media Permainan Monopoly Pada Mata Pelajaran IPS Terpadu Kelas VII Di SMP Negeri 14 Banda Aceh
Media sangat diperlukan dalam proses pembelajaran, karena ia berperan sebagai alat bantu pendengaran dan penglihatan peserta didik. Salah satu media yang bisa digunakan dalam pembelajaran adalah media permainan ular tangga dan monopoly dimana dengan menggunakan kedua media ini dapat melatih siswa untuk aktif berkerja sama dalam kelompok. Rumusan masalah dalam penelitian ini apakah hasil belajar siswa menggunakan media permainan ular tangga lebih baik dibandingkan dengan hasil belajar siswa menggunakan media permainan monopoly pada mata pelajaran IPS terpadu siswa kelas VII di SMP Negeri 14 Banda Aceh. Penelitian ini bertujuan untuk mengetahui apakah hasil belajar siswa menggunakan media permainan ular tangga lebih baik dibandingkan dengan hasil belajar siswa menggunakan media permainan monopoly pada mata pelajaran IPS terpadu siswa kelas VII di SMP Negeri 14 Banda Aceh. Populasi dalam penelitian ini adalah seluruh siswa kelas VII yaitu 3 kelas yang jumlah siswa 61 siswa, sedangkan pengambilan sampel dalam penelitian ini adalah dua kelas yaitu kelas VII1 sebanyak 22 siswa dan kelas VII2 sebanyak 21 siswa. Teknik pengumpulan data berupa pemberian tes kepada siswa, yakni pre-test dan post-test. Pre-test digunakan untuk mengetahui kemampuan peserta didik sebelum menerima pelajaran, sedangkan post-test dugunakan untuk mengetahui hasil belajar siswa setelah menerima pelajaran. Teknik pengolahan data dilakukan dengan uji-t. Hasil pengolahan data tersebut diperoleh nilai thitung = 3,24 yang lebih besar dari ttabel = 1,68 pada taraf signifikansi 5% dengan peluang 0,95 dan dk = 41, maka H0 ditolak dan Ha diterima. Simpulan yang dapat diambil adalah hasil belajar siswa menggunakan media permainan ular tangga lebih baik dibandingkan dengan hasil belajar siswa meggunakan media permainan monopoly pada mata pelajaran IPS terpadu siswa kelas VII di SMP Negeri 14 Banda Aceh
Data splitting as a countermeasure against hypothesis fishing: with a case study of predictors for low back pain
There is growing concern in the scientific community that many published scientific findings may represent spurious patterns that are not reproducible in independent data sets. A reason for this is that significance levels or confidence intervals are often applied to secondary variables or sub-samples within the trial, in addition to the primary hypotheses (multiple hypotheses). This problem is likely to be extensive for population-based surveys, in which epidemiological hypotheses are derived after seeing the data set (hypothesis fishing). We recommend a data-splitting procedure to counteract this methodological problem, in which one part of the data set is used for identifying hypotheses, and the other is used for hypothesis testing. The procedure is similar to two-stage analysis of microarray data. We illustrate the process using a real data set related to predictors of low back pain at 14-year follow-up in a population initially free of low back pain. âWidespreadnessâ of pain (pain reported in several other places than the low back) was a statistically significant predictor, while smoking was not, despite its strong association with low back pain in the first half of the data set. We argue that the application of data splitting, in which an independent party handles the data set, will achieve for epidemiological surveys what pre-registration has done for clinical studies
Coâfoundress confinement elicits kinship effects in a naturally subâsocial parasitoid
Kinship among interacting individuals is often associated with sociality and also with sex ratio effects. Parasitoids in the bethylid genus Goniozus are sub-social, with single foundress females exhibiting post-ovipositional maternal care via short-term aggressive host and brood defence against conspecific females. Due to local mate competition (LMC) and broods normally being produced by a single foundress, sex ratios are female biased. Contests between adult females are, however, not normally fatal and aggression is reduced when competing females are kin, raising the possibility of multi-foundress reproduction on some hosts. Here we screen for further life-history effects of kinship by varying the numbers and relatedness of foundresses confined together with a host resource and also by varying the size of host. We confined groups of 1 to 8 Goniozus nephantidis females together with a host for 5+ days. Multi-foundress groups were either all siblings or all non-siblings. Our chief expectations included that that competition for resources would be more intense among larger foundress groups but diminished by both larger host size and closer foundress relatedness, affecting both foundress mortality and reproductive output. From classical LMC theory, we expected that offspring group sex ratios would be less female biased when there were more foundresses and from extended LMC theory we expected that sex ratios would be more female biased when foundresses were close kin. We found that confinement led to the death of some females (11% overall) but only when host resources were most limiting. Mortality of foundresses was less common when foundresses were siblings. Developmental mortality among offspring was considerably higher in multi-foundress clutches but was unaffected by foundress relatedness. Groups of sibling foundresses collectively produced similar numbers of offspring to non-sibling groups. There was little advantage for individual females to reproduce in multi-foundress groups: single foundresses suppressed even the largest hosts presented and had the highest per capita production of adult offspring. Despite single-foundress reproduction being the norm, G. nephantidis females in multi-foundress groups appear to attune sex allocation according to both foundress number and foundress relatedness: broods produced by sibling foundresses had sex ratios similar to broods produced by single foundresses (ca. 11% males) whereas the sex ratios of broods produced by non-sibling females were approximately 20% higher and broadly increased with foundress number. We conclude that relatedness and host size may combine to reduce selection against communal reproduction on hosts and that, unlike other studied parasitoids, G. nephantidis sex ratios conform to predictions of both classical and extended LMC theor
Evaluation Method, Dataset Size or Dataset Content: How to Evaluate Algorithms for Image Matching?
Most vision papers have to include some evaluation work in order to demonstrate that the algorithm proposed is an improvement on existing ones. Generally, these evaluation results are presented in tabular or graphical forms. Neither of these is ideal because there is no indication as to whether any performance differences are statistically significant. Moreover, the size and nature of the dataset used for evaluation will obviously have a bearing on the results, and neither of these factors are usually discussed. This paper evaluates the effectiveness of commonly used performance characterization metrics for image feature detection and description for matching problems and explores the use of statistical tests such as McNemarâs test and ANOVA as better alternatives
Dietary patterns of adults living in Ouagadougou and their association with overweight
<p>Abstract</p> <p>Background</p> <p>Urbanization in developing countries comes along with changes in food habits and living conditions and with an increase in overweight and associated health risks. The objective of the study was to describe dietary patterns of adults in Ouagadougou and to study their relationship with anthropometric status of the subjects.</p> <p>Methods</p> <p>A qualitative food frequency questionnaire was administered to 1,072 adults living in two contrasted districts of Ouagadougou. Dietary patterns were defined by principal component analysis and described by multivariate analysis. Logistic regression was used to study their association with overweight.</p> <p>Results</p> <p>The diet was mainly made of cereals, vegetables and fats from vegetable sources. The two first components of the principal component analysis were interpreted respectively as a "snacking" score and as a "modern foods" score. Both scores were positively and independently associated with the economic level of households and with food expenditures (p †0.001 for both). The "snacking" score was higher for younger people (p = 0.004), for people having a formal occupation (p = 0.006), for those never married (p = 0.005), whereas the "modern foods" score was associated with ethnic group (p = 0.032) and district of residence (p < 0.001). Thirty-six percent of women and 14.5% of men were overweight (Body Mass Index > 25 kg/m<sup>2</sup>). A higher "modern foods" score was associated with a higher prevalence of overweight when confounding factors were accounted for (OR = 1.19 [95% CI 1.03-1.36]) but there was no relationship between overweight and the "snacking" score.</p> <p>Conclusions</p> <p>Modernisation of types of foods consumed was associated with the living conditions and the environment and with an increased risk of overweight. This should be accounted for to promote better nutrition and prevent non communicable diseases.</p
CGMP: cloud-assisted green multimedia processing
With continued advancements of mobile computing and communications, emerging novel multimedia services and applications have attracted lots of attention and been developed for mobile users, such as mobile social network, mobile cloud medical treatment, mobile cloud game. However, because of limited resources on mobile terminals, it is of great challenge to improve the energy efficiency of multimedia services. In this paper, we propose a cloud-assisted green multimedia processing architecture (CGMP) based on mobile cloud computing. Specifically, the tasks of multimedia processing with energy-extensive consumption can be offloaded to the cloud, and the face recognition algorithm with improved principal component analysis and nearest neighbor classifier is realized on CGMP based cloud platform. Experimental results show that the proposed scheme can effectively save the energy consumption of the equipment
Author Correction Extraction of mobile charge carrier photogeneration yield spectrum of ultrathin film metal oxide photoanodes for solar water splitting
Light absorption in strongly correlated electron materials can excite electrons and holes into a variety of different states. Some of these excitations yield mobile charge carriers, whereas others result in localized states that cannot contribute to photocurrent. The photogeneration yield spectrum, xi lamba , represents the wavelength dependent ratio between the contributing absorption that ultimately generates mobile charge carriers and the overall absorption. Despite being a vital material property, it is not trivial to characterize. Here, we present an empirical method to extract xi lamba through optical and external quantum efficiency measurements of ultrathin films. We applied this method to haematite photoanodes for water photo oxidation, and observed that it is self consistent for different illumination conditions and applied potentials. We found agreement between the extracted xi lamba spectrum and the photoconductivity spectrum measured by time resolved microwave conductivity. These measurements revealed that mobile charge carrier generation increases with increasing energy across haematite s absorption spectrum. Low energy non contributing absorption fundamentally limits the photoconversion efficiency of haematite photoanodes and provides an upper limit to the achievable photocurrent that is substantially lower than that predicted based solely on absorption above the bandgap. We extended our analysis to TiO2 and BiVO4 photoanodes, demonstrating the broader utility of the method for determining xi lamb
Extraction of mobile charge carrier photogeneration yield spectrum of ultrathin film metal oxide photoanodes for solar water splitting
Light absorption in strongly correlated electron materials can excite electrons and holes into a variety of different states. Some of these excitations yield mobile charge carriers, whereas others result in localized states that cannot contribute to photocurrent. The photogeneration yield spectrum, xi lamba , represents the wavelength dependent ratio between the contributing absorption that ultimately generates mobile charge carriers and the overall absorption. Despite being a vital material property, it is not trivial to characterize. Here, we present an empirical method to extract xi lamba through optical and external quantum efficiency measurements of ultrathin films. We applied this method to haematite photoanodes for water photo oxidation, and observed that it is self consistent for different illumination conditions and applied potentials. We found agreement between the extracted xi lamba spectrum and the photoconductivity spectrum measured by time resolved microwave conductivity. These measurements revealed that mobile charge carrier generation increases with increasing energy across haematite s absorption spectrum. Low energy non contributing absorption fundamentally limits the photoconversion efficiency of haematite photoanodes and provides an upper limit to the achievable photocurrent that is substantially lower than that predicted based solely on absorption above the bandgap. We extended our analysis to TiO2 and BiVO4 photoanodes, demonstrating the broader utility of the method for determining xi lamb
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