The analysis of journals topics and trend: text mining and word cloud

The objective of this study is to identify the major topics over time of 4 selected journals in the field of Information Science and Library Science by analyzing word usage and the frequency with which certain words are used in the journal. A further objective is to determine the future direction of research in related subject areas. The basis of the study uses the program R to collect, text mine, and analyze a published article’s word usage and concepts that are represented in a word cloud. Four journals were selected and collected from Web of Science (Thomson Reuters). The journal selection considered the 5-Year Impact Factor, the journal’s aims and scope, and subject uniqueness. The journals that were selected are: Journal of the Association for Information Science and Technology, Journal of the American Medical Informatics Association, Journal of Documentation, and Scientometrics. A total 8,148 articles were collected and analyzed

Community Currency in Korea

Community currency schemes were first introduced in Korea in 1998. Since then, there have been many efforts to use them but no report or academic research on the topic in Korea. Thus, we conducted a field investigation to identify the scope of community currency schemes in Korea and as of 2012 we found 43 groups which use them. The design elements were also investigated but most groups were in an under-developed state, therefore design elements were unidentifiable. Furthermore, we investigate how the community currency coordinators in Korea envision the system using Q-methodology, a method to find the subjective views on the topic. The result shows that the perception on community currency can be divided into four types: ‘Neighborhood as a community’ in which coordinators agree with mainstream economic values and view community currencies as a tool to revitalize the community and to empower local residents; ‘Alternative community’ in which coordinators view currencies as the means to resist the dominant neoliberal ideology; ‘Community through eco-friendly affinity groups’, in which the scheme is a tool to promote an ecologically-friendly lifestyle, and ‘Ecological community’, which represents coordinators who believe that it is an alternative to capitalism and a way to maintain an ecological community

Classification of breast mass abnormalities using denseness and architectural distortion

This paper presents an electronic second opinion system for the classification of mass abnormalities in mammograms into benign and malignant categories. This system is designed to help radiologists to reduce the number of benign breast cancer biopsies. Once a mass abnormality is detected and marked on a mammogram by a radiologist, two textural features, named denseness and architectural distortion, are extracted from the marked area. The denseness feature provides a measure of radiographic denseness of the marked area, whereas the architectural distortion feature provides a measure of its irregularity. These features are then fed into a neural network classifier. Receiver operating characteristic (ROC) analysis was conducted to evaluate the system performance. The area under the ROC curve reached 0.90 for the DDSM database consisting of 404 biopsy proven masses. A sensitivity analysis was also performed to examine the robustness of the introduced texture features to variations in sizes of abnormality markings

Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices

Sulf1 has ligand-dependent effects on canonical and non-canonical Wnt signalling

Wnt signalling plays essential roles during embryonic development and is known to be mis-regulated in human disease. There are many molecular mechanisms that ensure tight regulation of Wnt activity. One such regulator is the heparan-sulfate-specific 6-O-endosulfatase Sulf1. Sulf1 acts extracellularly to modify the structure of heparan sulfate chains to affect the bio-availability of Wnt ligands. Sulf1 could, therefore, influence the formation of Wnt signalling complexes to modulate the activation of both canonical and non-canonical pathways. In this study, we use well-established assays in Xenopus to investigate the ability of Sulf1 to modify canonical and non-canonical Wnt signalling. In addition, we model the ability of Sulf1 to influence morphogen gradients using fluorescently tagged Wnt ligands in ectodermal explants. We show that Sulf1 overexpression has ligand-specific effects on Wnt signalling: it affects membrane accumulation and extracellular levels of tagged Wnt8a and Wnt11b ligands differently, and inhibits the activity of canonical Wnt8a but enhances the activity of non-canonical Wnt11b

Data Analysis for Solar Energy Generation in a University Microgrid

This paper presents a data acquisition process for solar energy generation and then analyzes the dynamics of its data stream, mainly employing open software solutions such as Python, MySQL, and R. For the sequence of hourly power generations during the period from January 2016 to March 2017, a variety of queries are issued to obtain the number of valid reports as well as the average, maximum, and total amount of electricity generation in 7 solar panels. The query result on all-time, monthly, and daily basis has found that the panel-by panel difference is not so significant in a university-scale microgrid, the maximum gap being 7.1% even in the exceptional case. In addition, for the time series of daily energy generations, we develop a neural network-based trace and prediction model. Due to the time lagging effect in forecasting, the average prediction error for the next hours or days reaches 27.6%. The data stream is still being accumulated and the accuracy will be enhanced by more intensive machine learning

Impact of Blend Morphology on Interface State Recombination in Bulk Heterojunction Organic Solar Cells

International audienceThis work is a re-investigation of the impact of blend morphology and thermal annealing on the electrical performance of regioregular P3HT:PC 60 BM. The blend is first characterized by combining atomic force microscopy, X-rays diffraction and Time-of-Flight experiments. Then, current-voltage characteristics of photodiode devices are measured in the dark and under illumination. Finally, the existence of exponential tails of electronic gap states is experimentally confirmed by measuring the device spectral response in the sub-band gap regime. This method reveals the existence of a large density of gap states, which is partially reduced by successive annealing steps. The comparison between drift and diffusion 2 simulations and charge transport experiments show that, when band gap tails are properly taken into account, simulations can satisfactorily reproduce experimental currents under both dark and illumination conditions as a function of voltage and annealing time. This work further confirms the critical impact of tails states on the performance of solar cells

The Regulation of Germline Stem Cells and Their Neighbouring Somatic Cells in the Fruit Fly (Drosophila melanogaster)

The Drosophila germline stem cells (GSCs) remain as one of the most well-understood adult stem cells. The number of stem cells that self-renews and differentiates must be tightly controlled to maintain tissue homeostasis. The Drosophila GSCs are maintained by local signals emanated from the niche, which is composed of the surrounding somatic cells. Notably, GSC homeostasis is also known to be influenced by systemic signals and external stimuli. The Drosophila hormone ecdysone and its signalling cascade were found to regulate GSC homeostasis. The insulin signalling pathway as well as nutrient availability can also regulate GSC number. Furthermore, neuronal sex peptide signalling induced in female flies after mating was shown to increase GSC number. Hence, the Drosophila GSC system serves as a useful model towards understanding the mammalian stem cells. Compared with the mammalian stem cell models, the Drosophila GSC system is anatomically simpler where stem cells can be easily identified, imaged and manipulated genetically. Nevertheless, recent findings have facilitated our understanding into how GSCs and their neighbouring somatic cells sense and respond to changes in a variety of local, systemic and external stimuli