Multiple-choice discourse completion tasks in Japanese English language assessment

A new class of multiple-choice discourse completion tasks (MDCTs) is beginning to gain popularity in the Japan English as a Foreign Language (JEFL) assessment context. In this study, an experimental MDCT test was administered to a sample of Japanese university students. An item format analysis was conducted focusing on the construct validity and discrimination of MDCTs in measuring the English listening proficiency of JEFL speakers. Using a combination of classical test theory and Rasch analysis, test performance was analyzed in regard to two research questions: (a) whether a pragmatic proficiency construct is related to item difficulty, and (b) whether the use of different distractor types has an effect on item discrimination characteristics. The results suggest that a pragmatic proficiency construct plays a role in determining item difficulty on MDCTs, bringing into question the construct validity of MDCTs as a listening language proficiency measurement. Additionally, MDCT item discrimination might be affected by the type of distractors being used, hinting at possible ways to optimize discrimination of MDCTs in norm-referenced testing (NRT). Given the high probability of continued use of MDCTs in the JEFL context and the need for more investigation into these items, this study is hopefully an early step towards better and more informed MDCT test design and use

Control of plume interference effects on axisymmetric afterbodies

Plume interference effects on the axisymmetric flowfields around powered missiles are investigated using computational techniques. The study is mainly to understand the physics of the plume-induced shock and separation particularly at high plume to exit pressure ratios with and without shock-turbulent boundary layer control methods

Kondous un nuevo primate ceboide de el Mioceno de La Venta, Colombia

Reports by Grant-in-Aid for Overseas Scientific Survey1986 Grant-in-Aid for Scientific Research (Grant-in-Aid for Overseas Scientific Survey) Reports of Research Project (Number of Project 1984: 59041040, 1985: 60043041)Phylogenetic Studies of South American MonkeysHead Investigator 1984, 1985: Kyoto University, Primate Research Institutc, Professor, Yasuo NOGAM

Fission-Track Ages of the Villavieja Formation of the Miocene Honda Group in La Venta, Department of Huila, Colombia

Monbusho International Scientific Research Program Reports by 1990 and 1991 Grants for Field ResearchProject Number: 02041050 (1990 to 1991)Phylogenetic Studies of South American MonkeysHead Investigator: Yasuo NOGAMI, Professor, Primate Research Institute, Kyoto Universit

多数の仮想GPUを用いた際の計算性能モデルの構築

GPUを科学計算などの汎用的な目的で使用する技術はGPGPU(General-Purpose computing on Graphics Processing Units)として知られている.DS-CUDA(Distributed Shared CUDA)はネットワークを通じたサーバ上のGPUを仮想化するミドルウェアで,クライアント側でソフトを書き換えることなくGPU資源を用いたGPGPUが可能である.ただし，クライアントとサーバー間の通信がボトルネックになり易い.そこで本研究ではMDシミュレーションと行列の乗算を題材に,最大8つのGPUを用いて計算時間の測定を行い,DS-CUDAによる仮想GPUを用いた場合と,物理GPUをPCI Express拡張Boxを用いて直接扱う場合とで,性能モデルを構築し実際の時間と比較した.MDシミュレーションを通じて,DS-CUDAはPCI Express拡張Boxと比較して,GPU内の演算であるkernel関数の発行による通信に多くの時間がかかることがわかった.このことが,計算データ量小,GPU並列数大の条件下(1000粒子,8GPU)では,仮想GPUと物理GPUとの計算時間に高速なネットワーク(Infiniband)で1.5倍,低速なネットワーク(GigabitEthernet)では6倍の差が生じることがわかった.一方でGPU内での計算量が増大するに従って相対的に通信時間が占める割合は小さくなり,計算性能の向上のためにGPU並列数を大きくすることの有効性を示すことができた.行列の乗算においても同様の傾向が得られた一方で,計算データ量に対する通信量が多いことから通信スループットの影響により,GPU並列数を増やすことによる計算性能の向上は通信性能が十分,かつ計算データ量が十分大きい場合に限られることを示した.低速なGigabitEthernetネットワークではGPU並列数を大きくすることによる計算性能の向上を,測定実験の計算データ量領域内(最大8,190次行列,8GPU)で確認することはできず,構築したモデルもその事実を示した.以上の測定実験とモデル構築から,計算データ量が十分大きくGPU並列数が小さい場合は,仮想GPUがパフォーマンスを発揮できることを示した.電気通信大学201

Dimension reduction and shrinkage methods for high dimensional disease risk scores in historical data

Abstract Background Multivariable confounder adjustment in comparative studies of newly marketed drugs can be limited by small numbers of exposed patients and even fewer outcomes. Disease risk scores (DRSs) developed in historical comparator drug users before the new drug entered the market may improve adjustment. However, in a high dimensional data setting, empirical selection of hundreds of potential confounders and modeling of DRS even in the historical cohort can lead to over-fitting and reduced predictive performance in the study cohort. We propose the use of combinations of dimension reduction and shrinkage methods to overcome this problem, and compared the performances of these modeling strategies for implementing high dimensional (hd) DRSs from historical data in two empirical study examples of newly marketed drugs versus comparator drugs after the new drugs’ market entry—dabigatran versus warfarin for the outcome of major hemorrhagic events and cyclooxygenase-2 inhibitor (coxibs) versus nonselective non-steroidal anti-inflammatory drugs (nsNSAIDs) for gastrointestinal bleeds. Results Historical hdDRSs that included predefined and empirical outcome predictors with dimension reduction (principal component analysis; PCA) and shrinkage (lasso and ridge regression) approaches had higher c-statistics (0.66 for the PCA model, 0.64 for the PCA + ridge and 0.65 for the PCA + lasso models in the warfarin users) than an unreduced model (c-statistic, 0.54) in the dabigatran example. The odds ratio (OR) from PCA + lasso hdDRS-stratification [OR, 0.64; 95 % confidence interval (CI) 0.46–0.90] was closer to the benchmark estimate (0.93) from a randomized trial than the model without empirical predictors (OR, 0.58; 95 % CI 0.41–0.81). In the coxibs example, c-statistics of the hdDRSs in the nsNSAID initiators were 0.66 for the PCA model, 0.67 for the PCA + ridge model, and 0.67 for the PCA + lasso model; these were higher than for the unreduced model (c-statistic, 0.45), and comparable to the demographics + risk score model (c-statistic, 0.67). Conclusions hdDRSs using historical data with dimension reduction and shrinkage was feasible, and improved confounding adjustment in two studies of newly marketed medications

Wells turbine for wave energy conversion : a review

In the past twenty years, the use of wave energy systems has significantly increased, generally depending on the oscillating water column (OWC) concept. Wells turbine is one of the most efficient OWC technologies. This article provides an updated and a comprehensive account of the state of the art research on Wells turbine. Hence, it draws a roadmap for the contemporary challenges which may hinder future reliance on such systems in the renewable energy sector. In particular, the article is concerned with the research directions and methodologies which aim at enhancing the performance and efficiency of Wells turbine. The article also provides a thorough discussion of the use of computational fluid dynamics (CFD) for performance modeling and design optimization of Wells turbine. It is found that a numerical model using the CFD code can be employed successfully to calculate the performance characteristics of W-T as well as other experimental and analytical methods. The increase of research papers about CFD, especially in the last five years, indicates that there is a trend that considerably depends on the CFD method

Experimental Research on Performances of Air Turbines for a Fixed Oscillating Water Column-Type Wave Energy Converter

A fixed oscillating water column (OWC)-type wave energy converter is composed of an air chamber for primary conversion and an air turbine for secondary conversion. In the optimal design method of a fixed OWC-type wave energy converter, it is necessary to develop a design method which can consider the characteristics of incident wave motion, the motion of the internal free surface affected in the structure such as a partly submerged wall, the fluctuation of air pressure in an air chamber, the rotation of the air turbine. In this paper, the 2-dimensional wave tank tests in regular waves for the performance evaluation of the air turbines in a fixed OWC-type wave energy converter were conducted to obtain the data needed to make this design method. As the results, the effects of the impulse turbine specification such as the rotor inlet/outlet angle, the guide vane's number and the vane's setting angle on the primary and secondary conversion efficiencies are clarified experimentally. Furthermore, the performances of the Wells turbines with different number of blade are presented for comparison of the operating condition

Biomarkers and low risk in heart failure. Data from COACH and TRIUMPH

Aim Traditionally, risk stratification in heart failure (HF) emphasizes assessment of high risk. We aimed to determine if biomarkers could identify patients with HF at low risk for death or HF rehospitalization. Methods and results This analysis was a substudy of The Coordinating Study Evaluating Outcomes of Advising and Counselling in Heart Failure (COACH) trial. Enrolment of HF patients occurred before discharge. We defined low risk as the absence of death and/or HF rehospitalizations at 180 days. We tested a diverse group of 29 biomarkers on top of a clinical risk model, with and without N-terminal pro-B-type natriuretic peptide (NT-proBNP), and defined the low risk biomarker cut-off at the 10th percentile associated with high positive predictive value. The best performing biomarkers together with NT-proBNP and cardiac troponin I (cTnI) were re-evaluated in a validation cohort of 285 HF patients. Of 592 eligible COACH patients, the mean (± SD) age was 71 (± 11) years and median (IQR) NT-proBNP was 2521 (1301-5634) pg/mL. Logistic regression analysis showed that only galectin-3, fully adjusted, was significantly associated with the absence of events at 180 days (OR 8.1, 95% confidence interval 1.06-50.0, P = 0.039). Galectin-3, showed incremental value when added to the clinical risk model without NT-proBNP (increase in area under the curve from 0.712 to 0.745, P = 0.04). However, no biomarker showed significant improvement by net reclassification improvement on top of the clinical risk model, with or without NT-proBNP. We confirmed our results regarding galectin-3, NT-proBNP, and cTnI in the independent validation cohort. Conclusion We describe the value of various biomarkers to define low risk, and demonstrate that galectin-3 identifies HF patients at (very) low risk for 30-day and 180-day mortality and HF rehospitalizations after an episode of acute HF. Such patients might be safely discharged