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Spatio-Temporal Change of Dispersal Areas of Greater Kudu (Tragelaphus strepsiceros) in Lake Bogoria Landscape, Kenya
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作者 Beatrice Chepkoech Cheserek George Morara Ogendi Paul Mutua Makenzi 《Open Journal of Ecology》 2024年第3期183-198,共16页
Decline in wildlife populations is manifest globally, regionally and locally. A wildlife decline of 68% has been reported in Kenya’s rangelands with Baringo County experiencing more than 85% wildlife loss in the last... Decline in wildlife populations is manifest globally, regionally and locally. A wildlife decline of 68% has been reported in Kenya’s rangelands with Baringo County experiencing more than 85% wildlife loss in the last four decades. Greater Kudu (Tragelaphus strepsiceros) is endemic to Lake Bogoria landscape in Baringo County and constitutes a major tourist attraction for the region necessitating use of its photo on the County’s logo and thus a flagship species. Tourism plays a central role in Baringo County’s economy and is a major source of potential growth and employment creation. The study was carried out to assess spatio-temporal change of dispersal areas of Greater Kudu (GK) in Lake Bogoria landscape in the last four years for enhanced adaptive management and improved livelihoods. GK population distribution primary data collected in December 2022 and secondary data acquired from Lake Bogoria National Game Reserve (LBNGR) for 2019 and 2020 were digitized using in a Geographic Information System (GIS). Measures of dispersion and point pattern analysis (PPA) were used to analyze dispersal of GK population using GIS. Spatio-temporal change of GK dispersal in LBNR was evident thus the null hypothesis was rejected. It is recommended that anthropogenic activities contributing to GK’s habitat degradation be curbed by providing alternative livelihood sources and promoting community adoption of sustainable technologies for improved livelihoods. 展开更多
关键词 Spatio-Temporal change Dispersal Greater Kudu (Tragelaphus Strepsiceros) point Pattern Analysis (PPA) GIS
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Analysis of Viewing Paintings from the Perspective of Iconography
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作者 Min Li 《Journal of Contemporary Educational Research》 2024年第7期297-303,共7页
Distinguished from purely formalistic research methods,iconography pursues the interpretation of the hidden historical and humanistic connotations behind artworks,and is a discipline that combines visual text and cont... Distinguished from purely formalistic research methods,iconography pursues the interpretation of the hidden historical and humanistic connotations behind artworks,and is a discipline that combines visual text and content analysis methods.Combining the three stages of iconography proposed by Panofsky,the paper studies Shizeng Chen’s Viewing Paintings from the perspective of iconography,summarizing the formation and change of the images and contents of the artworks in the cultural system and civilization at that time,as well as their implied ideology,and analyzing the hidden spirit of the times and the historical significance behind them,so as to expound their iconographic significance.Through an in-depth discussion at three levels:pre-pictorial iconographic description,iconographic analysis,and iconographic interpretation,the facts and surface contents reproduced in the images,the traditional level of literary,artistic,and cultural knowledge,as well as the interpretation of the potential meanings are revealed. 展开更多
关键词 ICONOGRAPHY Viewing Paintings Spirit of the times Conceptual change
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Existence of Monotone Positive Solution for a Fourth-Order Three-Point BVP with Sign-Changing Green’s Function
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作者 Junrui Yue Yun Zhang Qingyue Bai 《Open Journal of Applied Sciences》 2024年第1期63-69,共7页
This paper is concerned with the following fourth-order three-point boundary value problem , where , we discuss the existence of positive solutions to the above problem by applying to the fixed point theory in cones a... This paper is concerned with the following fourth-order three-point boundary value problem , where , we discuss the existence of positive solutions to the above problem by applying to the fixed point theory in cones and iterative technique. 展开更多
关键词 Fourth-Order Three-point Boundary Value Problem Sign-Changing Green’s Function Fixed point Index Iterative Technique Monotone Positive Solution EXISTENCE
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Challenges and Countermeasures for Integrating the Protection of Environmental Rights into Actions for Addressing Climate Change
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作者 秦天宝 袁野阳光 《The Journal of Human Rights》 2023年第4期869-893,共25页
Climate change,which is the result of human activities,has wide-ranging impact.It poses a serious threat to human rights.Environmental rights are where the protection of the ecological environment and the development ... Climate change,which is the result of human activities,has wide-ranging impact.It poses a serious threat to human rights.Environmental rights are where the protection of the ecological environment and the development of human rights intersect.In view of the close relationship between the actions for addressing climate change and environmental rights,China should integrate the protection of environmental rights into the actions for addressing climate change,so as to achieve simultaneous development of both.In the process of coping with climate change,the right to climate stability that mainly pursues a“harmless”environment and the right to a more livable climate that pursues a“beautiful eco-environment”are specific manifestations of environmental rights and should be the priority of protection efforts.However,there are still some obstacles to achieving the coordinated development of the efforts to address climate change and the protection of environmental rights because traditional rights protection methods mainly give individuals subjective rights with the power to claim and are thus difficult to meet the needs of environmental rights protection in the context of climate change,and there are inherent value differences between responding to climate change and the realization of other human rights.Building a multi-level national obligation system to address climate change,giving full play to the role of courts in responding to climate change through moderate judicial activism,and coordinating the efforts to cope with climate change and the development of human rights under the guidance of a holistic system view are effective ways to overcome the aforementioned difficulties. 展开更多
关键词 actions for addressing climate change environmental rights judicial activism holistic system view
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Comparative Analysis of Climatic Change Trend and Change-Point Analysis for Long-Term Daily Rainfall Annual Maximum Time Series Data in Four Gauging Stations in Niger Delta
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作者 Masi G. Sam Ify L. Nwaogazie +4 位作者 Chiedozie Ikebude Jonathan O. Irokwe Diaa W. El Hourani Ubong J. Inyang Bright Worlu 《Open Journal of Modern Hydrology》 2023年第4期229-245,共17页
The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta re... The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling. 展开更多
关键词 Rainfall Time Series Data Climate change Trend Analysis Variation Rate change point Dates Non-Parametric Statistical Test
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Study of the Impact of Climate Change on Water Resources in the Sangha Watershed at Ouesso Hydrological Station, Republic of the Congo-Brazzaville (1961-2020)
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作者 Guy Blanchard Matete Moukoko Christian Ngoma Mvoundou +2 位作者 Joseph Mangouende Roddy Lendzea Christian Tathy 《Journal of Water Resource and Protection》 2023年第11期611-630,共20页
The Sangha River basin is the largest sub-basin of the Congo River basin, which drains the northern part of the Republic of the Congo-Brazzaville. It is the most important economic zone in this part of the country, wi... The Sangha River basin is the largest sub-basin of the Congo River basin, which drains the northern part of the Republic of the Congo-Brazzaville. It is the most important economic zone in this part of the country, with a strong timber industry, agriculture and hydroelectricity. The catchment also boasts the country’s third-largest river port, located in the town of Ouesso. Unfortunately, increasingly frequent low-water levels in recent years have led to a decline in river navigation and economic activities. So, the aim of this study is to show the effects of climate change over the last six decades in the Sangha watershed at Ouesso hydrological station, located in the north of the Republic of the Congo-Brazzaville, and elucidate its impact on water resources. To achieve this, several statistical and hydrological methods were used. The application of change-point or shift detection tests to flow series from 1961 to 2020 revealed variability in the hydrological cycle, characterized by two major phases of homogeneous flows: a wet surplus phase and a dry deficit phase. The results show one shift in flood flows in 1971 (Buishand test), one shift in yearly average flows or modules in 1971 (Pettitt test and Buishand test), and one shift in low-water flows in 1976, with all two tests. These disruptions were accompanied by a drop in flow of around 15.63%, 21.70% and 35.67%, on average, for floods, modules, and low-water, respectively, a drop in rainfall of around 9.6% and a rise in temperature of around 0.76?C. These flows show an overall downward trend. The calculated recession coefficients show that, over the entire study period, a recession occurred in March 1985. 展开更多
关键词 Sangha Watershed Republic of the Congo Pettitt Test Buishand Test change-point Recession Coefficient
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跨学科视野下对Point of View的重新界定 被引量:5
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作者 申丹 《上海交通大学学报(哲学社会科学版)》 北大核心 2023年第1期1-13,共13页
在西方叙事作品研究界,“point of view”自20世纪初以来一直是一个核心概念和热门话题。叙事学和文体学都十分关注这一话题。表面上看,两个学派对“point of view”进行了大致相同的探讨,而实际上两者在理念和路径上各行其道且相互排... 在西方叙事作品研究界,“point of view”自20世纪初以来一直是一个核心概念和热门话题。叙事学和文体学都十分关注这一话题。表面上看,两个学派对“point of view”进行了大致相同的探讨,而实际上两者在理念和路径上各行其道且相互排斥。叙事学界在探讨“point of view”时,将其囿于观察者的感知(区分“谁说”和“谁感知”),这种自我限制不合情理。与此相对照,文体学在探讨“point of view”时,聚焦于叙述者(说话者)的立场态度,这种自我限制也造成了很大问题。这两个学派在探讨“point of view”时各自的片面性以及相互之间的排他性还导致了不少理论上的混乱。这也对国内的研究造成了影响。本文在指出以往问题的基础上,对“point of view”提出切合实际的新的界定,旨在通过这一新的界定帮助推进理论探讨的发展并促进跨学科研究,以便对叙事作品进行更好、更为全面的分析。 展开更多
关键词 point of view 重新界定 叙事学与文体学 片面与混乱 跨学科研究
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Does Biochar Addition Influence the Change Points of Soil Phosphorus Leaching? 被引量:11
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作者 ZHAO Xiao-rong LI Dan +1 位作者 KONG Juan LIN Qi-mei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第3期499-506,共8页
Phosphorus change point indicating the threshold related to P leaching, largely depends on soil properties. Increasing data have shown that biochar addition can improve soil retention capacity of ions. However, we hav... Phosphorus change point indicating the threshold related to P leaching, largely depends on soil properties. Increasing data have shown that biochar addition can improve soil retention capacity of ions. However, we have known little about weather biochar amendment influence the change point of P leaching. In this study, two soils added with 0, 5, 10, 20, and 50 g biochar kg-1 were incubated at 25℃ for 14 d following adjusting the soil moisture to 50% water-holding capacity (WHC). The soils with different available P values were then obtained by adding a series of KH2PO4 solution (ranging from 0 to 600 mg P kg-1 soil), and subjecting to three cycles of drying and rewetting. The results showed that biochar addition significantly lifted the P change points in the tested soils, together with changes in soil pH, organic C, Olen-P and CaC12-P but little on exchangeable Ca and Mg, oxalate-extractable Fe and Al. The Olsen-P at the change points ranged from 48.65 to 185.07 mg kg-1 in the alluvial soil and 71.25 to 98.65 mg kg^-1 in the red soil, corresponding to CaCl2-P of 0.31-6.49 and 0.18-0.45 mg L~, respectively. The change points of the alluvial soil were readily changed by adding biochar compared with that of the red soil. The enhancement of change points was likely to be explained as the improvement of phosphate retention ability in the biochar-added soils. 展开更多
关键词 BIOCHAR SOIL PHOSPHORUS change point
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Sedimentation and morphological changes at Yuantuojiao Point, estuary of the North Branch, Changjiang River 被引量:11
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作者 XIE Li ZHANG Zhenke +2 位作者 ZHANG Yunfeng WANG Yaping HUANG Xianjin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第2期24-34,共11页
The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoffto the North Branch had led to the narrowing and shallowing of... The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoffto the North Branch had led to the narrowing and shallowing of the channel. The Yuantuojiao Point is located at the intersecting point connecting the North Branch of the Changjiang River and the Jiangsu coastline. Erosion cliffs are developed between the typical silty-muddy tidal flat and the salt marsh occupied by Spartina alterniflorea, and this has changed rapidly over the past few years. The sediment grain size analysis results of the surficial and two core samples indi- cate that the Yuantuoiiao Point tidal fiat experienced continuous accretional processes. Based upon 137Cs analysis results of the YT and YY Cores sampled from the tidal flat at the Yuantuojiao Point, the average sed- imentation rate of the YT Core was 2.30 cm/a from 1963 to 2007, and 2.38 cm/a from 1954 to 2007 for the YY Core. The sedimentation rates of both core locations have declined since the 1960s corresponding to the seaward reclamation at the Yuantuojiao Point. The average sedimentation rates at the Yuantnojiao Point were similar to that of the silty-muddy tidal flat at the northern ]iangsu coast, but lower than that of the south of the Changjiang River Estuary. According to field morphological investigations from 2006 to 2008 on the salt marsh at the Yuantuojiao Point, cliffs retreated markedly by storm surges and disappeared gradu- ally because of the rapid sedimentation on the silty-muddy tidal flat. The maximum annual retreat reached 10 m. The recent sedimentation and morphological changes of the Yuantuojiao Point tidal flat not only displayed the retreat of the salt marsh and the disappearance of cliffs, but also was accompanied by rapid sedimentation of the silty-muddy tidal flat and the salt marsh, indicating the responses to the tidal currents, storm surges, Spartina alterniflorea trapping sediments and large-scale reclamation. The sediment grain size and their trends, southward coastal flow, and sandspits of the longshore bars suggest that the main sediment source at the Yuantuoijao Point, estuary of the North Branch was possibly from the Changjiang River before 1958, since then, it has been from the south of the submarine radial sand ridges of the southern Huanghai Sea (Yellow Sea). 展开更多
关键词 sedimentation rate morphological changes the tidal fiat salt marsh cliff seaward reclamation Yuantuojiao point the North Branch of the Changjiang River
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Analysis of Change Point in Surface Temperature Time Series Using Cumulative Sum Chart and Bootstrapping for Asansol Weather Observation Station, West Bengal, India 被引量:3
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作者 Ansar Khan Soumendu Chatterjee +1 位作者 Dipak Bisai Nilay Kanti Barman 《American Journal of Climate Change》 2014年第1期83-94,共12页
This paper aims to detect the short-term as well as long-term change point in the surface air temperature time series for Asansol weather observation station, West Bengal, India. Temperature data for the period from 1... This paper aims to detect the short-term as well as long-term change point in the surface air temperature time series for Asansol weather observation station, West Bengal, India. Temperature data for the period from 1941 to 2010 of the said weather observatory have been collected from Indian Meteorological Department, Kolkata. Variations and trends of annual mean temperature, annual mean maximum temperature and annual minimum temperature time series were examined. The cumulative sum charts (CUSUM) and bootstrapping were used for the detection of abrupt changes in the time series data set. Statistically significant abrupt changes and trends have been detected. The major change point in the annual mean temperatures occurred around 1986 (0.57°C) at the period of 25 years in the long-term regional scale. On the other side, the annual mean maximum and annual mean minimum temperatures have distinct change points at level 1. There are abrupt changes in the year 1961 (Confidence interval 1961, 1963) for the annual mean maximum and 1994 (Confidence interval 1993, 1996) for the annual mean minimum temperatures at a confidence level of 100% and 98%, respectively. Before the change, the annual mean maximum and annual mean minimum temperatures were 30.90°C and 23.99°C, respectively, while after the change, the temperatures became 33.93°C and 24.84°C, respectively. Over the entire period of consideration (1941-2010), 11 forward and backward changes were found in total. Out of 11, there are 3 changes (1961, 1986 and 2001) in annual mean temperatures, 4 changes (1957, 1961, 1980 and 1994) in annual mean maximum temperatures, and rest 4 changes (1968, 1981, 1994 and 2001) are associated with annual mean minimum temperature data set. 展开更多
关键词 BOOTSTRAPPING change point CUSUM Temperature Time SERIES
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Consistency of the <i>φ</i>-Divergence Based Change Point Estimator 被引量:1
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作者 Mwelu Susan Anthony G. Waititu +1 位作者 Peter N. Mwita Charity Wamwea 《Open Journal of Statistics》 2020年第5期832-849,共18页
This paper utilizes a change-point estimator based on <span>the </span><span style="font-style:italic;">φ</span><span>-</span><span>divergence. Since </span>&... This paper utilizes a change-point estimator based on <span>the </span><span style="font-style:italic;">φ</span><span>-</span><span>divergence. Since </span><span "=""><span>we seek a </span><span>near perfect</span><span> translation to reality, then locations of parameter change within a finite set of data have to be accounted for since the assumption of </span><span>stationary</span><span> model is too restrictive especially for long time series. The estimator is shown to be consistent through asymptotic theory and finally proven through simulations. The estimator is applied to the generalized Pareto distribution to estimate changes in the scale and shape parameters.</span></span> 展开更多
关键词 change point CONSISTENCY φ-Divergence Kullback-Leibler Generalized Pareto Distribution
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The SCUSUM Estimation of Variance Change Point in Linear Process 被引量:1
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作者 ZHAO Wen-zhi XIA Zhi-ming 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第2期170-173,共4页
这份报纸在线性过程考虑一个变化变化点的评价问题。一个 SCUSUM 类型变化点评估者的一致性被证明,它集中的率被建立。平均数未知的盒子也被考虑。
关键词 变化变化点 线性过程 集中评价
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Limit Distribution of the φ-Divergence Based Change Point Estimator
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作者 Mwelu Susan Anthony G. Waititu +1 位作者 Peter N. Mwita Charity Wamwea 《Open Journal of Statistics》 2021年第3期337-350,共14页
The assumption of stationarity is too restrictive especially for long time series. This paper studies the change point problem through a change point estimator based on the <span style="color:#4F4F4F;font-fami... The assumption of stationarity is too restrictive especially for long time series. This paper studies the change point problem through a change point estimator based on the <span style="color:#4F4F4F;font-family:Simsun;font-size:14px;white-space:normal;background-color:#FFFFFF;">&phi;</span><span><span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-divergence which provides a rich set of distance like measures between pairs of distributions. The change point problem is considered in the following sub-fields: the problem of divergence estimation, testing for the homogeneity between two samples as well as estimating the time of change. The asymptotic distribution of the change point estimator is estimated by the limiting distribution of a stochastic process within given bounds through asymptotic theory surrounding the likelihood theory. The distribution is found to converge to that of a standardized Brownian bridge process.</span></span></span> 展开更多
关键词 change point φ-Divergence ESTIMATOR Test Statistic DISTRIBUTION Wald
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The Power of Change-Point Test for Two-Phase Regression
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作者 To Van Ban Nguyen Thi Quyen 《Applied Mathematics》 2014年第19期2994-3000,共7页
In this paper, the roughness of the model function to the basis functions and its properties have been considered. We also consider some conditions to take the limit of the roughness when the observations are i.i.d. A... In this paper, the roughness of the model function to the basis functions and its properties have been considered. We also consider some conditions to take the limit of the roughness when the observations are i.i.d. An explicit formula to calculate the power of change-point test for the two phases regression through the roughness was obtained. 展开更多
关键词 change-point TEST the POWER the ROUGHNESS RANDOM Design
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Probabilistic modeling of multifunction radars with autoregressive kernel mixture network
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作者 Hancong Feng Kaili.Jiang +4 位作者 Zhixing Zhou Yuxin Zhao Kailun Tian Haixin Yan Bin Tang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期275-288,共14页
The task of modeling and analyzing intercepted multifunction radars(MFRs)pulse trains is vital for cognitive electronic reconnaissance.Existing methodologies predominantly rely on prior information or heavily constrai... The task of modeling and analyzing intercepted multifunction radars(MFRs)pulse trains is vital for cognitive electronic reconnaissance.Existing methodologies predominantly rely on prior information or heavily constrained models,posing challenges for non-cooperative applications.This paper introduces a novel approach to model MFRs using a Bayesian network,where the conditional probability density function is approximated by an autoregressive kernel mixture network(ARKMN).Utilizing the estimated probability density function,a dynamic programming algorithm is proposed for denoising and detecting change points in the intercepted MFRs pulse trains.Simulation results affirm the proposed method's efficacy in modeling MFRs,outperforming the state-of-the-art in pulse train denoising and change point detection. 展开更多
关键词 Probabilistic forecasting Multifunction radar Unsupervised learning change point detection Outlier detection
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Child’s Point of View vs.Adult’s in Melville’s Early Two Stories
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作者 YANG Jiayun 《Sino-US English Teaching》 2023年第10期392-395,共4页
This paper aims to study the functions of two different points of view from the perspective of narratology,namely,the point of view of the adult and the one of the child,in two of Herman Melville’s early stories.By c... This paper aims to study the functions of two different points of view from the perspective of narratology,namely,the point of view of the adult and the one of the child,in two of Herman Melville’s early stories.By contrasting these two functions of the different perspectives,the author of this paper draws the conclusion that the child has a unique and significant perspective in Melville’s works. 展开更多
关键词 point of view child’s point of view adult’s point of view
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Discrete Software Reliability Growth Modeling for Errors of Different Severity Incorporating Change-point Concept 被引量:4
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作者 D.N.Goswami Sunil K.Khatri Reecha Kapur 《International Journal of Automation and computing》 EI 2007年第4期396-405,共10页
Several software reliability growth models (SRGM) have been developed to monitor the reliability growth during the testing phase of software development. In most of the existing research available in the literatures... Several software reliability growth models (SRGM) have been developed to monitor the reliability growth during the testing phase of software development. In most of the existing research available in the literatures, it is considered that a similar testing effort is required on each debugging effort. However, in practice, different types of faults may require different amounts of testing efforts for their detection and removal. Consequently, faults are classified into three categories on the basis of severity: simple, hard and complex. This categorization may be extended to r type of faults on the basis of severity. Although some existing research in the literatures has incorporated this concept that fault removal rate (FRR) is different for different types of faults, they assume that the FRR remains constant during the overall testing period. On the contrary, it has been observed that as testing progresses, FRR changes due to changing testing strategy, skill, environment and personnel resources. In this paper, a general discrete SRGM is proposed for errors of different severity in software systems using the change-point concept. Then, the models are formulated for two particular environments. The models were validated on two real-life data sets. The results show better fit and wider applicability of the proposed models as to different types of failure datasets. 展开更多
关键词 Discrete software reliability growth model non-homogeneous Poisson process fault severity change point probability generating function.
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On the Points of View Used in Mansfield' s “Miss Brill”
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作者 郑丹清 《海外英语》 2012年第11X期206-207,共2页
Point of view has been a big playground for study in fiction for about a century.Mansfield' s "Miss Brill" is featured by its successful use of points of view.This paper will discuss how Mansfield' s... Point of view has been a big playground for study in fiction for about a century.Mansfield' s "Miss Brill" is featured by its successful use of points of view.This paper will discuss how Mansfield' s choice of a particular point of view helps to communicate the central theme of the story. 展开更多
关键词 point of VIEW "Miss Brill" theME
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Time Sequence Change-Point Model of Electrostatic State Parameters of Aircraft Engine 被引量:2
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作者 Fu Yu Wei Dongdong +1 位作者 Zuo Hongfu Feng Zhengxing 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第1期126-134,共9页
Electrostatic monitoring technology of particle charging information can facilitate online monitoring of aero-engine,which effectively enhances engine fault diagnosis and health managements.Unlike traditional engine s... Electrostatic monitoring technology of particle charging information can facilitate online monitoring of aero-engine,which effectively enhances engine fault diagnosis and health managements.Unlike traditional engine state monitoring technologies,aircraft engine monitoring by gas path electrostatic monitoring not only covers the predicted information source itself,but also detects the information that can provide an early warnings for initial fault states through gas path charging levels.This paper establishes a non-stationary time sequence change-point model for anomaly recognition of electrostatic signals based on change-point theory combined with difference method of non-stationary time series.Finally,electrostatic induction data were utilized by the engine life test for a particular aircraft to validate the proposed algorithm.The results indicate that the activity level and the event rate were0.5—0.8(nc)and 50%,respectively,which were far greater than 4—12(pc)and 0—4% under normal working conditions of the engine. 展开更多
关键词 AERO-ENGINE STATE identification ELECTROSTATIC monitoring technology time series change-point STATISTICS
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Damage Position of Concrete Beam Based on Test of Even Change Point
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作者 张开鹏 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2004年第3期72-73,共2页
The quantitative analysis of damage position of concrete beam is established.The method of damage position free of models used in this paper is based on the variations of strain mode and test of even change point.The ... The quantitative analysis of damage position of concrete beam is established.The method of damage position free of models used in this paper is based on the variations of strain mode and test of even change point.The discrete model and the position criterion are presented.Numerical example is conducted,the result demonstrates that the method of damage position is correct and effective. 展开更多
关键词 test of even change point strain mode damage position
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