1,247 research outputs found
Data for: ROSA/LSTF test and RELAP5 code analyses on primary feed-and-bleed operation during total loss-of-feedwater transient of PWR
No full textExperimental data with the LSTF (large-scale test facility) and calculated results by RELA5/MOD3.3 code, used to support the findings of this study, are available from the corresponding author (Takeshi Takeda) upon request
Memory-efficient large-scale linear support vector machine
No full textStochastic gradient descent has been advanced as a computationally efficient method for large-scale problems. In classification problems, many proposed linear support vector machines as very effective classifiers. However, they assume that the data is already in memory which might not be always the case. Recent work suggests a classical method that divides such a problem into smaller blocks and then solves the sub-problems iteratively. We show that a simple modification of shrinking the dataset early will produce significant saving in computation and memory. We further find that on problems larger than previously considered, our approach is able to reach solutions on top-end desktop machines while competing methods cannot
Simultaneous pursuit of out-of-sample performance and sparsity in index tracking portfolios
No full textIndex tracking is a passive investment strategy in which a fund (e.g., an ETF: exchange traded fund) manager purchases a set of assets to mimic a market index. The tracking error, i.e., the difference between the performances of the index and the portfolio, may be minimized by buying all the assets contained in the index. However, this strategy results in a considerable transaction cost and, accordingly, decreases the return of the constructed portfolio. On the other hand, a portfolio with a small cardinality may result in poor out-of-sample performance. Of interest is, thus, constructing a portfolio with good out-of-sample performance, while keeping the number of assets invested in small (i.e., sparse). In this paper, we develop a tracking portfolio model that addresses the above conflicting requirements by using a combination of L0- and L2-norms. The L2-norm regularizes the overdetermined system to impose smoothness (and hence has better out-of-sample performance), and it shrinks the solution to an equally-weighted dense portfolio. On the other hand, the L0-norm imposes a cardinality constraint that achieves sparsity (and hence a lower transaction cost). We propose a heuristic method for estimating portfolio weights, which combines a greedy search with an analytical formula embedded in it. We demonstrate that the resulting sparse portfolio has good tracking and generalization performance on historic data of weekly and monthly returns on the Nikkei 225 index and its constituent companies
Estimation of Gaussian mixture models via tensor moments with application to online learning
No full textIn this paper, we present an alternating gradient descent algorithm for estimating parameters of a spherical Gaussian mixture model by the method of moments (AGD-MoM). We formulate the problem as a constrained optimisation problem which simultaneously matches the third order moments from the data, represented as a tensor, and the second order moment, which is the empirical covariance matrix. We derive the necessary gradients (and second derivatives), and use them to implement alternating gradient search to estimate the parameters of the model. We show that the proposed method is applicable in both a batch as well as in a streaming (online) setting. Using synthetic and benchmark datasets, we demonstrate empirically that the proposed algorithm outperforms the more classical algorithms like Expectation Maximisation and variational Bayes
Supplemental Material - Decreased peak expiratory flow rate associated with mortality in idiopathic pulmonary fibrosis: A preliminary report
No full textSupplemental Material for Decreased peak expiratory flow rate associated with mortality in idiopathic pulmonary fibrosis: A preliminary report by Kohei Fujita, Hirotsugu Ohkubo, Akiko Nakano, Norihisa Takeda, Kensuke Fukumitsu, Satoshi Fukuda, Yoshihiro Kanemitsu, Takehiro Uemura, Tomoko Tajiri, Ken Maeno, Yutaka Ito, Tetsuya Oguri, Yoshiyuki Ozawa, Takayuki Murase and Akio Niimi in Chronic Respiratory Disease</p
Skelosophusa prolixa Ng and Takeda 1994
No full textRemarks on Skelosophusa prolixa Ng and Takeda, 1994 (Fig. 4) The first author discovered five specimens from northern Madagascar in the unidentified collection of the NHM (NHM 2009.119, NHM 2009.120 -121, NHM 2009.122, NHM 2009.123, NHM 2009.124) that proved to belong to Skelosophusa prolixa. All of these specimens were collected from Riviére Cave, Cañon Forestier, Ankarana, 60 km south of Diego Suarez, northern Madagascar, 8 August-27 September 1986, by N. W. Lear and S. U. Fowler. Although the locality is similar to that reported for the holotype, it may be possible that these specimens are topotypic, and were collected at the same time as the original type series. However, it is difficult to be certain of this because the date of collection and the names of the collectors were not supplied in the original description (Ng and Takeda, 1994). Skelosophusa prolixa was previously known only from two specimens collected from this same locality. Th e holotype described by Ng and Takeda (1994) has a CW of 25.6 mm and CL of 18.8 mm; these two measurements give a cw/cl ratio of 1.3 (compared to 1.4 for the present specimens). This species possesses a number of adaptations (e.g. normal length eyestalks but with reduced corneas, lack of pigmentation of the carapace and legs, and extremely long ambulatory legs, p2-p5) typical of true cave-adapted species of freshwater crabs (Ng and Takeda, 1994). Th e adult male specimen among the new material photographed here (Fig. 4 A–D) (CW 29.3 mm) is larger than the holotype male (CW 25.6 mm) and shows characters of the cheliped that have not previously been described. For example, the immovable finger of the major cheliped of S. prolixa has one large, fused molar tooth in adults, whereas that of the holotype male, a smaller specimen, has only small teeth (Ng and Takeda, 1994).Published as part of Cumberlidge, Neil & Meyer, Kristin, 2009, A new species of Foza Reed & Cumberlidge, 2006 from northern Madagascar (Decapoda, Brachyura, Potamoidea, Potamonautidae), with a redescription of F. goudoti (H. Milne Edwards, 1853) comb. n., and comments on Skelosophusa prolixa Ng & Takeda, 1994, pp. 77-89 in ZooKeys 18 (18) on page 87, DOI: 10.3897/zookeys.18.102, http://zenodo.org/record/57649
Data for: ROSA/LSTF test and RELAP5 code analyses on primary feed-and-bleed operation during total loss-of-feedwater transient of PWR
No full textExperimental data with the LSTF (large-scale test facility) and calculated results by RELA5/MOD3.3 code, used to support the findings of this study, are available from the corresponding author (Takeshi Takeda) upon request.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
The effectiveness of interventions to treat severe acute malnutrition in young children: a systematic review
No full textSevere acute malnutrition (SAM) arises as a consequence of a sudden period of food shortage and is associated with loss of a person’s body fat and wasting of their skeletal muscle. Many of those affected are already undernourished and are often susceptible to disease. Infants and young children are the most vulnerable as they require extra nutrition for growth and development, have comparatively limited energy reserves and depend on others. Undernutrition can have drastic and wide-ranging consequences for the child’s development and survival in the short and long term. Despite efforts made to treat SAM through different interventions and programmes, it continues to cause unacceptably high levels of mortality and morbidity. Uncertainty remains as to the most effective methods to treat severe acute malnutrition in young children.ObjectivesTo evaluate the effectiveness of interventions to treat infants and children aged < 5 years who have SAM.Data sourcesEight databases (MEDLINE, EMBASE, MEDLINE In-Process & Other Non-Indexed Citations, CAB Abstracts Ovid, Bioline, Centre for Reviews and Dissemination, EconLit EBSCO and The Cochrane Library) were searched to 2010. Bibliographies of included articles and grey literature sources were also searched. The project expert advisory group was asked to identify additional published and unpublished references.Review methodsPrior to the systematic review, a Delphi process involving international experts prioritised the research questions. Searches were conducted and two reviewers independently screened titles and abstracts for eligibility. Inclusion criteria were applied to the full texts of retrieved papers by one reviewer and checked independently by a second. Included studies were mapped to the research questions. Data extraction and quality assessment were undertaken by one reviewer and checked by a second reviewer. Differences in opinion were resolved through discussion at each stage. Studies were synthesised through a narrative review with tabulation of the results.ResultsA total of 8954 records were screened, 224 full-text articles were retrieved, and 74 articles (describing 68 studies) met the inclusion criteria and were mapped. No evidence focused on treatment of children with SAM who were human immunodeficiency virus sero-positive, and no good-quality or adequately reported studies assessed treatments for SAM among infants < 6 months old. One randomised controlled trial investigated fluid resuscitation solutions for shock, with none adequately treating shock. Children with acute diarrhoea benefited from the use of hypo-osmolar oral rehydration solution (H-ORS) compared with the standard World Health Organization-oral rehydration solution (WHO-ORS). WHO-ORS was not significantly different from rehydration solution for malnutrition (ReSoMal), but the safety of ReSoMal was uncertain. A rice-based ORS was more beneficial than glucose-based ORSs, and provision of zinc plus a WHO-ORS had a favourable impact on diarrhoea and need for ORS. Comparisons of different diets in children with persistent diarrhoea produced conflicting findings. For treating infection, comparison of amoxicillin with ceftriaxone during inpatient therapy, and routine provision of antibiotics for 7 days versus no antibiotics during outpatient therapy of uncomplicated SAM, found that neither had a significant effect on recovery at the end of follow-up. No evidence mapped to the next three questions on factors that affect sustainability of programmes, long-term survival and readmission rates, the clinical effectiveness of management strategies for treating children with comorbidities such as tuberculosis and Helicobacter pylori infection and the factors that limit the full implementation of treatment programmes. Comparison of treatment for SAM in different settings showed that children receiving inpatient care appear to do as well as those in ambulatory or home settings on anthropometric measures and response time to treatment. Longer-term follow-up showed limited differences between the different settings. The majority of evidence on methods for correcting micronutrient deficiencies considered zinc supplements; however, trials were heterogeneous and a firm conclusion about zinc was not reached. There was limited evidence on either supplementary potassium or nicotinic acid (each produced some benefits), and nucleotides (not associated with benefits). Evidence was identified for four of the five remaining questions, but not assessed because of resource limitation.LimitationsThe systematic review focused on key questions prioritised through a Delphi study and, as a consequence, did not encompass all elements in the management of SAM. In focusing on evidence from controlled studies with the most rigorous designs that were published in the English language, the systematic review may have excluded other forms of evidence. The systematic review identified several limitations in the evidence base for assessing the effectiveness of interventions for treating young children with severe acute malnutrition, including a lack of studies assessing the different interventions; limited details of study methods used; short follow-up post intervention or discharge; and heterogeneity in participants, interventions, settings, and outcome measures affecting generalisability.ConclusionsFor many of the most highly ranked questions evidence was lacking or inconclusive. More research is needed on a range of topic areas concerning the treatment of infants and children with SAM. Further research is required on most aspects of the management of SAM in children < 5 years, including intravenous resuscitation regimens for shock, management of subgroups (e.g. infants < 6 months old, infants and children with SAM who are human immunodeficiency virus sero-positive) and on the use of antibiotics.FundingThe National Institute for Health Research Technology Assessment programme.<br/
Measurement of Solar Differential Rotation by Absolutely Calibrated Iodine-Cell Spectroscopy
No full textThe iodine-cell technique, which is known to be efficient in precisely establishing Doppler velocity shifts, was once applied by the author to measuring the solar differential rotation based on full-disk spectroscopic observations (Takeda and Ueno, Sol. Phys. 270, 447, 2011). However, the data reduction procedure (in simple analogy with the stellar case) adopted therein was not necessarily adequate, because specific characteristic involved with the disk-resolved Sun (i.e., center-limb variation of line strengths) was not properly taken into consideration. Therefore, this problem is revisited based on the same data but with an application to theoretical spectrum fitting, which can yield absolute heliocentric radial velocities (v_obs) in a consistent manner as shown in the study of solar gravitational redshift (Takeda and Ueno, Sol. Phys. 281, 551, 2012). Likewise, instead of converting v_obs into omega (angular velocity) at each disk point, which suffers considerable errors especially near the central meridian, omega was derived this time by applying the least squares analysis to a dataset comprising v_obs values at many points. This new analysis resulted in omega (deg/day) = 13.92 (+/- 0.03) -1.69(+/- 0.34)(sin psi)^2 -2.37(+/- 0.62) (sin psi)^4 (psi: the heliographic latitude) along with the gravitational redshift of 675 m/s, which are favorably compared with previous publications. In addition, how the distribution of observing points on the disk affects the result is also examined, which reveals that rotation parameters may suffer appreciable errors depending on cases.18 pages, 8 figures, with ancillary material; accepted for publication in Solar Physic
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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