检索结果-南通市图书馆

Software Project Effort Estimation Based on Multiple Parametric Models Generated Through Data Clustering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Computer Science & Technology 2007年第3期22卷 371-378页

作者： juan j.Cuadrado Gallego daniel Rodríguez Miguel Angel Sicilia Miguel Garre Rubio Angel García Crespo Department of Computer Science The University of Alcalá AlcaláSpain Department of Computer Science Carlos Ⅲ University.Madrid Spain

Parametric software effort estimation models usually consists of only a single mathematical relationship. With the advent of software repositories containing data from heterogeneous projects, these types of models suffer from poor adjustment and predictive accuracy. One possible way to alleviate this problem is the use of a set of mathematical equations obtained through dividing of the historical project datasets according to different parameters into subdatasets called partitions. In turn, partitions are divided into clusters that serve as a tool for more accurate models. In this paper, we describe the process, tool and results of such approach through a case study using a publicly available repository, ISBSG. Results suggest the adequacy of the technique as an extension of existing single-expression models without making the estimation process much more complex that uses a single estimation model. A tool to support the process is also presented. Keywords software engineering, software measurement, effort estimation, clustering

关键词： software engineering software measurement effort estimation clustering

Supplemental Smartamine M in higher-energy diets during the prepartal period improves hepatic biomarkers of health and oxidative status in Holstein cows

在线全文

学校读者我要写书评

暂无评论

journal of Animal Science and Biotechnology 2017年第3期8卷 624-635页

作者： Mario Vailati-Riboni johan S.Osorio Erminio Trevisi daniel Luchini juan j.Loor Mammalian Nutri Physio Genomics Department of Animal Sciences and Division of Nutritional SciencesUniversity of IllinoisUrbanaIL 61801USA Istituto di Zootecnica Facolt àdi Scienze Agrarie Alimentari e AmbientaliUniversità Cattolica del Sacro Cuore29122 PiacenzaItaly Adisseo NA AlpharettaGA 30022USA. Dairy and Food Science Department South Dakota State University1111 College Ave113H Alfred DairyScience HallBrookings SD 57007USA

Background： Feeding higher-energy prepartum is a common practice in the dairy industry. However, recent data underscore how it could reduce performance, deepen negative energy balance, and augment inflammation and oxidative stress in fresh cows. We tested the effectiveness of rumen-protected methionine in preventing the negative effect of feeding a higher-energy prepartum. Multiparous Holstein cows were fed a control lower-energy diet（CON, 1.24 Mcal/kg DM; high-straw） during the whole dry period（-50 d）, or were switched to a higher-energy（OVE, 1.54 Mcal/kg DM）, or OVE plus Smartamine M（OVE ＋ SM; Adisseo NA） during the last 21 d before *** cows received the same lactation diet（1.75 Mcal/kg DM）. Smartamine M was top-dressed on the OVE diet（0.07% of DM） from -21 through 30 d in milk（DIM）. Liver samples were obtained via percutaneous biopsy at -10, 7 and 21 DIM. Expression of genes associated with energy and lipid metabolism, hepatokines, methionine cycle, antioxidant capacity and inflammation was ***： Postpartal dry matter intake, milk yield, and energy-corrected milk were higher in CON and OVE ＋ SM compared with OVE. Furthermore, milk protein and fat percentages were greater in OVE ＋ SM compared with CON and OVE. Expression of the gluconeogenic gene PCK1 and the lipid-metabolism transcription regulator PPARA was again greater with CON and OVE ＋ SM compared with OVE. Expression of the lipoprotein synthesis enzyme MTTP was lower in OVE ＋ SM than CON or OVE. Similarly, the hepatokine FGF21, which correlates with severity of negative energy balance, was increased postpartum only in OVE compared to the other two groups. These results indicate greater liver metabolism and functions to support a greater production in OVE ＋ SM. At 7 DIM, the enzyme GSR involved in the synthesis of glutathione tended to be upregulated in OVE than CON-fed cows, suggesting a greater antioxidant demand in overfed cows. Feeding OVE ＋ SM resulted in lower similar express

关键词： Energy Methionine Nutrigenomics Transition period

Extreme developmental temperatures result in morphological abnormalities in painted turtles(Chrysemys picta):a climate change perspective

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2013年第2期8卷 197-208页

作者： Rory S.TELEMECO daniel A.WARNER Molly K.REIDA Fredric j.jANZEN Department of Ecology Evolution and Organismal BiologyIowa State UniversityAmesIowaUSA

Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of *** examined the effects of heat and cold waves during embryonic development of painted turtles(Chrysemys picta)in natural nests on the occurrence of abnormal shell morphologies in *** found that nests exposed to extreme hot temperatures for>60 h produced more hatchlings with abnormalities than nests exposed to extreme hot temperatures for shorter periods,regardless of whether or not nesting females displayed abnormal *** observed no effect of extreme cold nest temperatures on the occurrence of hatchlings with ***,the frequency of nesting females with abnormal shell morphologies was approximately 2-fold lower than that of their offspring,suggesting that such abnormalities are negatively correlated with survival and *** turtles could potentially buffer their offspring from extreme heat by altering aspects of nesting behavior,such as choosing shadier nesting *** addressed this hypothesis by examining the effects of shade cover on extreme nest temperatures and the occurrence of hatchling *** shade cover was negatively correlated with the occurrence of extreme hot nest temperatures,it was not significantly correlated with ***,female choice of shade cover does not appear to be a viable target for selection to reduce hatchling *** results suggest that increases in the frequency and intensity of heat waves associated with climate change might perturb developmental programs and thereby reduce the fitness of entire cohorts of turtles.

关键词： anomaly fundamental niche incubation nesting behavior scute deformity

Color Cherenkov imaging of clinical radiation therapy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2021年第12期10卷 2380-2386页

作者： daniel A.Alexander Anthony Nomezine Lesley A.jarvis David j.Gladstone Brian W.Pogue Petr Bruza Thayer School of Engineering Dartmouth CollegeHanoverNHUSA DoseOptics LLC LebanonNHUSA Geisel School of Medicine Dartmouth CollegeHanoverNHUSA Norris Cotton Cancer Center DartmouthHitchcock Medical CenterLebanonNHUSA

Color vision is used throughout medicine to interpret the health and status of *** radiation used in radiation therapy produces broadband white light inside tissue through the Cherenkov effect,and this light is attenuated by tissue features as it leaves the *** this study,a novel time-gated three-channel camera was developed for the first time and was used to image color Cherenkov emission coming from patients during *** spectral content was interpreted by comparison with imaging calibrated tissue *** shades of Cherenkov emission in radiotherapy can be used to interpret tissue blood volume,oxygen saturation and major vessels within the body.

关键词： therapy clinical Color

Mate choice decisions by searchers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2013年第2期59卷 184-199页

作者： daniel D. WIEGMANN Lisa M. ANGELONI Steven M. SEUBERT j. GordonWADE Department of Biological Sciences and j. P. Scott Center for Neuroscience Mind and Behavior Bowling Green State University Bowling Green OH 43403 USA Department of Biology Colorado State University Fort Collins CO 80523 USA Department of Mathematics and Statistics Bowling Green State University Bowling Green OH 43403 USA

For more than two decades rudimentary versions of the fixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers. The theory that surrounds these models has expanded markedly over this time period. In this paper, we review and extend results derived from these models, with a focus on the empirical analysis of searcher behavior. The basic models are impractical for empirical purposes because they rely on the as- sumption that searchers--and, for applied purposes, researchers--assess prospective mates based on their quality, the fitness consequences of mate choice decisions. Here we expound versions of the models that are more empirically useful, reformulated to reflect decisions based on male phenotypic characters. For some organisms, it may be possible to use preference functions to de- rive predictions from the reformulated models and thereby avoid difficulties associated with the measurement of male quality per se. But predictions derived from the two models are difficult to differentiate empirically, regardless of how the models are formu- lated. Here we develop ideas that illustrate how this goal might be accomplished. In addition, we clarify how the variability of male quality should be evaluated and we extend what is known about how this variability influences searcher behavior under each model. More general difficulties associated with the empirical study of mate choice decisions by searchers are also discussed [Current Zoology 59 （2）： 184-199, 2013].

关键词： Dispersive order Fixed sample strategy Mate choice Preference functions Sequential search Stochastic dominance

The current perspective of the PA 1957 gas well pillar study and its implications for longwall gas well pillars

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Mining Science and Technology 2021年第1期31卷 117-126页

作者： Peter Zhang daniel Su Chris Mark CDC NIOSH Pittsburgh Mining Research DivisionPittsburghPA 15236USA Mine Safety and Health Administration PittsburghPA 15217USA

Many states rely upon the Pennsylvania 1957 Gas Well Pillar Study to evaluate the coal barrier surrounding gas *** study included 77 gas well failure cases that occurred in the Pittsburgh and Freeport coal seams over a 25-year *** the time,coal was mined using the room-and-pillar mining method with full or partial pillar recovery,and square or rectangle pillars surrounding the gas wells were left to protect the *** study provided guidelines for pillar sizes under different overburden depths up to 213 m(700 ft).The 1957 study has also been used to determine gas well pillar sizes in longwall mines since longwall mining began in the 1970 *** original study was developed for room-and-pillar mining and could be applied to gas wells in longwall chain pillars under shallow ***,under deep cover,severe deformations in gas wells have occurred in longwall chain ***,with a better understanding of coal pillar mechanics,new insight into subsidence movements induced by retreat mining,and advances in numerical modeling,it has become both critically important and feasible to evaluate the adequacy of the 1957 study for longwall gas well *** this paper,the data from the 1957 study is analyzed from a new perspective by considering various factors,including overburden depth,failure location,failure time,pillar safety factor(SF),and floor *** pillar SF and floor pressure are calculated by considering abutment pressure induced by full pillar recovery.A statistical analysis is performed to find correlations between various factors and helps identify the most significant factors for the stability of gas wells influenced by retreat *** analyzing the data from the 1957 study,the guidelines for gas well pillars in the 1957 study are evaluated for their adequacy for roomand-pillar mining and their applicability to longwall *** modeling is used to model the stability of gas wells by quantifying the mining-induced s

关键词： Gas well pillar Pennsylvania 1957 gas well pillar study Room-and-pillar mining Longwall mining

Real-world treatment attrition rates in advanced esophagogastric cancer

在线全文

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2020年第39期26卷 6027-6036页

作者： Erica S Tsang Howard j Lim daniel j Renouf janine M Davies jonathan M Loree Sharlene Gill Department of Medicine BC CancerVancouver V5Z 4E6Canada Division of Medical Oncology University of British ColumbiaVancouver V5Z 4E6Canada

BACKGROUND Over the last decade,multiple agents have demonstrated efficacy for advanced esophagogastric cancer(EGC).Despite the availability of later lines of therapy,there remains limited real-world data about the treatment attrition rates between lines of *** To characterize the use and attrition rates between lines of therapy for patients with advanced *** We identified patients who received at least one cycle of chemotherapy for advanced EGC between july 1,2017 and july 31,2018 across six regional centers in British Columbia(BC),***,treatment,and outcomes data were *** Of 245 patients who received at least one line of therapy,median age was 66 years(IQR 58.2-72.3)and 186(76%)were male,Eastern Cooperative Oncology Group(ECOG)performance status 0/1(80%),gastric vs GEj(36%vs 64%).Histologies included adenocarcinoma(78%),squamous cell carcinoma(8%),and signet ring(14%),with 31%HER2 positive.72%presented with de novo disease,and 25%had received previous *** was a high level of treatment attrition,with patients receiving only one line of therapy n=122,50%),two lines n=83,34%),three lines n=34,14%),and four lines n=6,2%).Kaplan-Meier analysis demonstrated improved survival with increasing lines of therapy(median overall survival 7.7 vs 16.6 vs 22.8 vs 40.4 mo,P<0.05).On multivariable Cox regression,improved survival was associated with better baseline ECOG and increased lines of therapy(P<0.05).CONCLUSION The steep attrition rates between therapies highlight the unmet need for more efficacious early-line treatment options for patients with advanced EGC.

关键词： Esophagogastric cancer Gastric cancer Treatment attrition Systemic therapy Treatment outcomes Real-world evidence

A meta-analysis of global crop water productivity of three leading world crops(wheat,corn,and rice)in the irrigated areas over three decades

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Digital Earth 2020年第8期13卷 939-975页

作者： daniel j.Foley Prasad S.Thenkabail Itiya P.Aneece Pardhasaradhi G.Teluguntla Adam j.Oliphant Western Geographic Science Center United States Geological SurveyFlagstaffAZUSA Bay Area Environmental Research Institute(BAERI) NASA Research ParkMoffett FieldCAUSA

The overarching goal of this study was to perform a comprehensive metaanalysis of irrigated agricultural Crop Water Productivity(CWP)of the world’s three leading crops:wheat,corn,and rice based on three decades of remote sensing and non-remote sensing-based ***,CWP data from 148 crop growing study sites(60 wheat,43 corn,and 45 rice)spread across the world were gathered from published articles spanning 31 different *** was overwhelming evidence of a significant increase in CWP with an increase in latitude for predominately northern hemisphere *** example,corn grown in latitude 40–50°had much higher mean CWP(2.45 kg/m^(3))compared to mean CWP of corn grown in other latitudes such as 30–40°(1.67 kg/m^(3))or 20–30°(0.94 kg/m^(3)).The same trend existed for wheat and rice as *** soils,none of the CWP values,for any of the three crops,were statistically ***,mean CWP in higher latitudes for the same soil was significantly higher than the mean CWP for the same soil in lower *** applied for all three crops *** wheat,the global CWP categories were low(≤0.75 kg/m^(3)),medium(>0.75 to1.25 to≤1.75 kg/m^(3)),and high(>1.75 kg/m^(3)).For rice the global CWP categories were low(≤0.70 kg/m^(3)),medium(>0.70 to≤1.25 kg/m^(3)),and high(>1.25 kg/m^(3)).USA and China are the only two countries that have consistently high CWP for wheat,corn,and *** and India have medium CWP for wheat and ***’s corn,however,has low ***,Turkey,Netherlands,Mexico,and Israel have high CWP for ***,Argentina,and Hungary have high CWP for corn,and Philippines has high CWP for *** other countries have either low or medium CWP for all three *** on data in this study,the highest consumers of water for crop production also have the most potential for water *** countries are USA

关键词： Crop water productivity sustainable agriculture water use/water savings wheat corn rice food and water security

Soil water content and nitrogen differentially correlate with multidimensional leaf traits of two temperate broadleaf species

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2023年第6期45卷 694-701页

作者： Ming-Yue jin daniel j.johnson Guang-Ze jin Qing-Xi Guo Zhi-Li Liu Center for Ecological Research Key Laboratory of Sustainable ForestEcosystem Management-Ministry of EducationNortheast Asia Biodiversity Research CenterNortheast Forestry UniversityHarbin 150040HeilongjiangChina School of Forest Resources and Conservation University of FloridaGainesvilleFLUSA

The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental ***,correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain *** measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species(Betula platyphylla and Acer mono)in four mixed broadleaved-Korean pine(Pinus koraiensis)forests along a latitudinal gradient in Northeast *** found that leaf economics traits and vein traits were decoupled in shade-intolerant species,Betula platphylla,but significantly coupled in a shadetolerant species,*** found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant ***,leaf economic traits were positively correlated with the soil water gradient for both species,whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant *** economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species,vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant *** study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light *** recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.

关键词： Leaf trait multidimensionality Economics traits Vein traits Soil water content Soil total nitrogen Shade tolerance