The NaYF4：yb3＋,Tb3＋ （Xyb： 0.20, XTb： 0.04） materials were prepared using the co-precipitation method, lne as-preparea material was washed either with or without water in addition to ethanol and thereafter annea...The NaYF4：yb3＋,Tb3＋ （Xyb： 0.20, XTb： 0.04） materials were prepared using the co-precipitation method, lne as-preparea material was washed either with or without water in addition to ethanol and thereafter annealed for 5 h at 500℃. This resulted in materials with moderate or very high up-conversion luminescence intensity, respectively. The structural study carried out with X-ray powder diffraction revealed microstrains in the rare earth （R） sublattice that were relaxed for the material with very high up-conversion intensity thus decreasing energy losses. The local structural details were investigated with R LⅢ and Y K edge ex- tended X-ray absorption fine structure （EXAFS） using synchrotron radiation. Around 10 tool.% of the Yb3＋ ions were found to occupy the Na site in the material with very high up-conversion intensity. These Yb species formed clusters with the Tb3＋ ions occupying the regular Na/R sites. Such clustering enhanced the energy transfer between Yb3＋ and Tb3＋ thus intensifying the up-conversion emission.展开更多
The identification between chaotic systems and stochastic processes is not easy since they have numerous similarities. In this study, we propose a novel approach to distinguish between chaotic systems and stochastic p...The identification between chaotic systems and stochastic processes is not easy since they have numerous similarities. In this study, we propose a novel approach to distinguish between chaotic systems and stochastic processes based on the component reordering procedure and the visibility graph algorithm. It is found that time series and their reordered components will show diverse characteristics in the ＇visibility domain＇. For chaotic series, there are huge differences between the degree distribution obtained from the original series and that obtained from the corresponding reordered component. For correlated stochastic series, there are only small differences between the two degree distributions. For uncorrelated stochastic series, there are slight differences between them. Based on this discovery, the well-known Kullback Leible divergence is used to quantify the difference between the two degree distributions and to distinguish between chaotic systems, correlated and uncorrelated stochastic processes. Moreover, one chaotic map, three chaotic systems and three different stochastic processes are utilized to illustrate the feasibility and effectiveness of the proposed method. Numerical results show that the proposed method is not only effective to distinguish between chaotic systems, correlated and uncorrelated stochastic processes, but also easy to operate.展开更多
In fixed order quantity systems,uncertainty in lead time is expressed as a set of scenarios with occurrence probabilities,and the mean and variance in demand distribution are supposed to be changeable according to a k...In fixed order quantity systems,uncertainty in lead time is expressed as a set of scenarios with occurrence probabilities,and the mean and variance in demand distribution are supposed to be changeable according to a known pattern.A new concept of "dynamic robust optimal reorder point" is proposed in this paper and its value is calculated as a "robust optimal reorder point function with respect to reorder time".Two approaches were employed in determining the dynamic optimal reorder point.The first is a shortage rate satisfaction approach and the second is a backorder cost minimization approach.The former aims at finding the minimum value of reorder point at each reorder time which satisfies the condition that the cumulative distribution function (CDF) of shortage rate under a given set of scenarios in lead time is greater than or equal to a basic CDF of shortage rate predetermined by a decision-maker.In the latter approach,the CDF of closeness of reorder point is defined at each reorder time to express how close to the optimal reorder points under the set of scenarios,and the dynamic optimal reorder point is defined according to stochastic ordering.Some numerical examples demonstrate the features of these dynamic robust optimal reorder points.展开更多
In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural o...In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.展开更多
In market, excess demands for many products can be met by reorder even during one period, and retailers usually adopt substitution strategy for more benefit. Under the retailer＇s substitution strategy and permission ...In market, excess demands for many products can be met by reorder even during one period, and retailers usually adopt substitution strategy for more benefit. Under the retailer＇s substitution strategy and permission of reorder, we develop the profits maximization model for the two-substitutable-product inventory problem with stochastic demands and proportional costs and revenues. We show that the objective function is concave and submodular, and therefore the optimal policy exists. We present the optimal conditions for order quantity and provide some properties of the optimal order quantities. Comparing our model with Netessine and Rudi＇s, we prove that reorder and adoption of the substitution strategy can raise the general profits and adjust down the general stock level.展开更多
In this paper and presupposing a Christian Weltanschauung or biblical worldview, I will argue that vices are disordered loves and virtues are reordered loves. The Christian gospel makes the ~ansition from the former t...In this paper and presupposing a Christian Weltanschauung or biblical worldview, I will argue that vices are disordered loves and virtues are reordered loves. The Christian gospel makes the ~ansition from the former to the latter state possible. The seven deadly sins--pride, envy, anger, sloth, avarice, gluttony, and lust--are disordered loves; the seven cardinal virtues--faith, hope, love, courage, justice, temperance, and prudence--are reordered loves. Since love is central in human experience---rooted in the heart--it is also central in moral formation and deformation. Love （or the lack thereof） is the key to understanding the nature and action of both human vice and virtue.展开更多
Lexicalized reordering models are very important components of phrasebased translation systems.By examining the reordering relationships between adjacent phrases,conventional methods learn these models from the word a...Lexicalized reordering models are very important components of phrasebased translation systems.By examining the reordering relationships between adjacent phrases,conventional methods learn these models from the word aligned bilingual corpus,while ignoring the effect of the number of adjacent bilingual phrases.In this paper,we propose a method to take the number of adjacent phrases into account for better estimation of reordering models.Instead of just checking whether there is one phrase adjacent to a given phrase,our method firstly uses a compact structure named reordering graph to represent all phrase segmentations of a parallel sentence,then the effect of the adjacent phrase number can be quantified in a forward-backward fashion,and finally incorporated into the estimation of reordering models.Experimental results on the NIST Chinese-English and WMT French-Spanish data sets show that our approach significantly outperforms the baseline method.展开更多
Matrix-based graph visualization is effective in revealing relationships among entities in graphs.The visibility of structural patterns depends on the ordering of rows/columns in matrices.Most existing approaches main...Matrix-based graph visualization is effective in revealing relationships among entities in graphs.The visibility of structural patterns depends on the ordering of rows/columns in matrices.Most existing approaches mainly settle on an ideal ordering according to quality metrics,which emphasize certain types of patterns but ignore others.This paper proposes a summarization-based pattern-aware reordering approach to highlight multiple patterns simultaneously.First,the pattern-aware graph summarization utilizes the Minimum Description Length(MDL)technique to identify various types of patterns from the input graph.Second,we propose a coarse-to-fine reordering mechanism to generate matrixbased visualizations that maintain the structure of all identified patterns.Experimental results of two comparative studies and a user study on several datasets demonstrate that our approach simultaneously highlights more types of patterns than other approaches and performs well across multiple quality metrics.展开更多
This study investigated how advanced Chinese students of English construct clause relations when construing English texts. A deconstructed text was distributed in class to 42 graduate students of linguistics, who were...This study investigated how advanced Chinese students of English construct clause relations when construing English texts. A deconstructed text was distributed in class to 42 graduate students of linguistics, who were required to organize the clauses into a conceivably good text. The result suggests that these students seemed to rely on explicit cohesive words （anaphoric references and repetitions） rather than meaning relations in text construction. They seemed to have difficulties in using cataphoric contextual information and the popular discourse pattern from general to specific. This study calls for an enhanced awareness of logico-semantic relations in teaching and learning text construction.展开更多
Various government documents tend to put the reordering of relationship together with institutional reform and functional transformation.If we fail to understand this important issue,we will be unable to understand Ch...Various government documents tend to put the reordering of relationship together with institutional reform and functional transformation.If we fail to understand this important issue,we will be unable to understand China’s national governance system.The reordering of relationship has four dimensions:government and market;central and local government;the economy and society;and government and society.The routes to this reordering can be divided into separation,retention and postponement.On the one hand,the conflicts between these routes have affected China’s national governance structure,so that it seeks a balance between closure and opening up;on the other,the course taken by the reordering of relationship is rooted in the demands for generality and modernity that coexist within China’s national governance.One could say that the straightening out of relationship has reshaped the distinctive features of this governance.In the course of continuous reordering,some of its important elements have undergone a crucial change.From the perspective of the reordering of relationship,the openness with which these relations have been absorbed into a larger system is crucial to the future transformation of China’s national governance.展开更多
Semantic Web has emerged to make web content machine-readable,and with the rapid increase in the number of web pages,its importance has increased.Resource description framework(RDF)is a special data graph format where...Semantic Web has emerged to make web content machine-readable,and with the rapid increase in the number of web pages,its importance has increased.Resource description framework(RDF)is a special data graph format where Semantic Web data are stored and it can be queried by SPARQL query language.The challenge is to find the optimal query order that results in the shortest period of time.In this paper,the discrete Artificial Bee Colony(dABCSPARQL)algorithm is proposed,based on a novel heuristic approach,namely reordering SPARQL queries.The processing time of queries with different shapes and sizes is minimized using the dABCSPARQL algorithm.The performance of the proposed method is evaluated on chain,star,cyclic,and chain-star queries of different sizes from the Lehigh University Benchmark(LUBM)dataset.The results obtained by the proposed method are compared with those of ARQ(a SPARQL processor for Jena)query engine,the Ant System,the Elitist Ant System,and MAX-MIN Ant System algorithms.The experiments demonstrate that the proposed method significantly reduces the processing time,and in most queries,the reduction rate is higher compared with other optimization methods.展开更多
Geometry based block partitioning （GBP） has been shown to achieve better performance than the tree structure based block partitioning （TSBP） of H.264. However, the residual blocks of GBP mode after motion compensa...Geometry based block partitioning （GBP） has been shown to achieve better performance than the tree structure based block partitioning （TSBP） of H.264. However, the residual blocks of GBP mode after motion compensation still present some non-vertical/non-horizontal orientations, and the conventional discrete cosine transform （DCT） may generate many high-frequency coefficients. To solve this problem, in this paper we propose a video coding approach by using GBP and reordering DCT （RDCT） techniques. In the proposed approach, GBP is first applied to partition the macroblocks. Then, before performing DCT, a reordering operation is used to adjust the pixel positions of the residual macroblocks based on the partition information. In this way, the partition information of GBP can be used to represent the reordering information of RDCT, and the bitrate can be reduced. Experimental results show that, compared to H.264/AVC, the proposed method achieves on average 6.38% and 5.69% bitrate reductions at low and high bitrates, respectively.展开更多
Objective:To evaluate the performance of orthokeratology(ortho-k)lens reordering using software-designed system,so as to determine the feasibility of ortho-k lens reordering without discontinuing lens wear.Methods:Thi...Objective:To evaluate the performance of orthokeratology(ortho-k)lens reordering using software-designed system,so as to determine the feasibility of ortho-k lens reordering without discontinuing lens wear.Methods:This study is a retrospective analysis of data of ortho-k lens wearers who had a history of short-term discontinuation of lens wear.A total of 94 individuals aged over 8 years with spherical equivalent refraction ranging from-0.50 to-6.50 diopters were included.The corneal topography data at baseline(before ortho-k)and after lens wear discontinuation(cessation of ortho-k treatment)were imported separately into the lens-design software,along with corresponding refraction data.Subsequently,corneal and lens parameters were generated and compared.Intraclass correlation coefficients(ICC)were calculated,and Bland and Altman analyses were conducted.Results:All 94 children were involved in the retrospective analysis.Compared with baseline data,there was a high level of consistency between Rwo(without discontinuation)and Rwith(with discontinuation),with an ICC of 0.96(P<0.001).Furthermore,the comparison of lens parameters generated by the Easyfit software between baseline and after short-term discontinuation showed a high degree of consistency,with all of the ICC values exceeding 0.90.Similar results were obtained using the WAVE software,as both ICC values and Bland-Altman plots demonstrated a high level of consistency in lens parameters between two conditions(nearly all data points fell within the 95%LoAs).Conclusions:It is feasible to directly reorder new ortho-k lenses using software fitting approaches.However,further investigations are necessary to validate their practicability in a clinical setting.展开更多
随着人工智能生成内容技术的迅猛发展和大语言模型(large language models,LLMs)广泛应用,智算中心的网络面临着严峻挑战,流量控制是优化网络性能的重要方法.综述细粒度流量控制领域的关键问题及解决方案,重点梳理了自适应负载均衡机制...随着人工智能生成内容技术的迅猛发展和大语言模型(large language models,LLMs)广泛应用,智算中心的网络面临着严峻挑战,流量控制是优化网络性能的重要方法.综述细粒度流量控制领域的关键问题及解决方案,重点梳理了自适应负载均衡机制、主动式拥塞控制机制和乱序包重排机制3个方面的研究进展.自适应负载均衡能够有效规避网络内部的拥塞,主动式拥塞控制用于预防自适应负载均衡无法避免的最后一跳拥塞问题,而乱序包重排解决了自适应负载均衡过程中可能引发的数据包乱序问题,三者协同作用确保了网络在高负载、高延迟等复杂环境下的稳定性与高效性.在此基础上,阐述了当前主流智算中心采用的关键技术方案以及目前支持细粒度流量控制的网络设备,最后总结了该领域尚未解决的关键问题及可能的解决方案,并对未来发展趋势进行了展望.展开更多
远程直接内存访问(RDMA)已经成为数据中心网络(DCN)跨节点高性能数据传输的关键技术。但是,现有的RDMA传输协议,如基于融合以太网的RDMA版本2(RDMA over Converged Ethernet version 2,RoCEv2),仅支持顺序数据包处理。为进一步提高数据...远程直接内存访问(RDMA)已经成为数据中心网络(DCN)跨节点高性能数据传输的关键技术。但是,现有的RDMA传输协议,如基于融合以太网的RDMA版本2(RDMA over Converged Ethernet version 2,RoCEv2),仅支持顺序数据包处理。为进一步提高数据传输的灵活性,支持多路径传输与选择性重传,如何使RDMA网卡处理乱序数据包成为当下的研究热点。本文总结了RDMA乱序数据包的产生原因与处理方法,同时对涉及的相关技术如数据包排序、乱序数据包直写、位图管理、丢包检测、跨工作队列元素(WQE)的内存一致性、路径选择等进行了介绍。展开更多
基金Project supported by Palomaa-Erikoski foundation,Academy of Finland,Conselho Nacional de Desenvolvimento Cientifico e Tec-nológico(Brazil)Finnish Funding Agency for Technology and Innovation(TEKES),Nordic Energy Research(Oslo,Norway)the European Community's Seventh Framework Programme(FP7/2007-2013)(312284)
文摘The NaYF4：yb3＋,Tb3＋ （Xyb： 0.20, XTb： 0.04） materials were prepared using the co-precipitation method, lne as-preparea material was washed either with or without water in addition to ethanol and thereafter annealed for 5 h at 500℃. This resulted in materials with moderate or very high up-conversion luminescence intensity, respectively. The structural study carried out with X-ray powder diffraction revealed microstrains in the rare earth （R） sublattice that were relaxed for the material with very high up-conversion intensity thus decreasing energy losses. The local structural details were investigated with R LⅢ and Y K edge ex- tended X-ray absorption fine structure （EXAFS） using synchrotron radiation. Around 10 tool.% of the Yb3＋ ions were found to occupy the Na site in the material with very high up-conversion intensity. These Yb species formed clusters with the Tb3＋ ions occupying the regular Na/R sites. Such clustering enhanced the energy transfer between Yb3＋ and Tb3＋ thus intensifying the up-conversion emission.
基金Supported by the National Natural Science Foundation of China under Grant No U1530126
文摘The identification between chaotic systems and stochastic processes is not easy since they have numerous similarities. In this study, we propose a novel approach to distinguish between chaotic systems and stochastic processes based on the component reordering procedure and the visibility graph algorithm. It is found that time series and their reordered components will show diverse characteristics in the ＇visibility domain＇. For chaotic series, there are huge differences between the degree distribution obtained from the original series and that obtained from the corresponding reordered component. For correlated stochastic series, there are only small differences between the two degree distributions. For uncorrelated stochastic series, there are slight differences between them. Based on this discovery, the well-known Kullback Leible divergence is used to quantify the difference between the two degree distributions and to distinguish between chaotic systems, correlated and uncorrelated stochastic processes. Moreover, one chaotic map, three chaotic systems and three different stochastic processes are utilized to illustrate the feasibility and effectiveness of the proposed method. Numerical results show that the proposed method is not only effective to distinguish between chaotic systems, correlated and uncorrelated stochastic processes, but also easy to operate.
基金Project (No.21510152) supported by the Grant-in-Aid for Scientific Research (C),Japan
文摘In fixed order quantity systems,uncertainty in lead time is expressed as a set of scenarios with occurrence probabilities,and the mean and variance in demand distribution are supposed to be changeable according to a known pattern.A new concept of "dynamic robust optimal reorder point" is proposed in this paper and its value is calculated as a "robust optimal reorder point function with respect to reorder time".Two approaches were employed in determining the dynamic optimal reorder point.The first is a shortage rate satisfaction approach and the second is a backorder cost minimization approach.The former aims at finding the minimum value of reorder point at each reorder time which satisfies the condition that the cumulative distribution function (CDF) of shortage rate under a given set of scenarios in lead time is greater than or equal to a basic CDF of shortage rate predetermined by a decision-maker.In the latter approach,the CDF of closeness of reorder point is defined at each reorder time to express how close to the optimal reorder points under the set of scenarios,and the dynamic optimal reorder point is defined according to stochastic ordering.Some numerical examples demonstrate the features of these dynamic robust optimal reorder points.
基金supported by the National High-Technology Research and Development Program of China （Grant No.2003AA123310）, and the National Natural Science Foundation of China （Grant Nos.60332030, 60572157）
文摘In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.
文摘In market, excess demands for many products can be met by reorder even during one period, and retailers usually adopt substitution strategy for more benefit. Under the retailer＇s substitution strategy and permission of reorder, we develop the profits maximization model for the two-substitutable-product inventory problem with stochastic demands and proportional costs and revenues. We show that the objective function is concave and submodular, and therefore the optimal policy exists. We present the optimal conditions for order quantity and provide some properties of the optimal order quantities. Comparing our model with Netessine and Rudi＇s, we prove that reorder and adoption of the substitution strategy can raise the general profits and adjust down the general stock level.
文摘In this paper and presupposing a Christian Weltanschauung or biblical worldview, I will argue that vices are disordered loves and virtues are reordered loves. The Christian gospel makes the ~ansition from the former to the latter state possible. The seven deadly sins--pride, envy, anger, sloth, avarice, gluttony, and lust--are disordered loves; the seven cardinal virtues--faith, hope, love, courage, justice, temperance, and prudence--are reordered loves. Since love is central in human experience---rooted in the heart--it is also central in moral formation and deformation. Love （or the lack thereof） is the key to understanding the nature and action of both human vice and virtue.
基金supported by the National Natural Science Foundation of China（No.61303082） the Research Fund for the Doctoral Program of Higher Education of China（No.20120121120046）
文摘Lexicalized reordering models are very important components of phrasebased translation systems.By examining the reordering relationships between adjacent phrases,conventional methods learn these models from the word aligned bilingual corpus,while ignoring the effect of the number of adjacent bilingual phrases.In this paper,we propose a method to take the number of adjacent phrases into account for better estimation of reordering models.Instead of just checking whether there is one phrase adjacent to a given phrase,our method firstly uses a compact structure named reordering graph to represent all phrase segmentations of a parallel sentence,then the effect of the adjacent phrase number can be quantified in a forward-backward fashion,and finally incorporated into the estimation of reordering models.Experimental results on the NIST Chinese-English and WMT French-Spanish data sets show that our approach significantly outperforms the baseline method.
基金supported by the National Natural Science Foundation of China under Grant Nos.62132017,62421003,and 62202244the“Pioneer”and“Leading Goose”Research and Development Program of Zhejiang Province of China under Grant No.2024C01167.
文摘Matrix-based graph visualization is effective in revealing relationships among entities in graphs.The visibility of structural patterns depends on the ordering of rows/columns in matrices.Most existing approaches mainly settle on an ideal ordering according to quality metrics,which emphasize certain types of patterns but ignore others.This paper proposes a summarization-based pattern-aware reordering approach to highlight multiple patterns simultaneously.First,the pattern-aware graph summarization utilizes the Minimum Description Length(MDL)technique to identify various types of patterns from the input graph.Second,we propose a coarse-to-fine reordering mechanism to generate matrixbased visualizations that maintain the structure of all identified patterns.Experimental results of two comparative studies and a user study on several datasets demonstrate that our approach simultaneously highlights more types of patterns than other approaches and performs well across multiple quality metrics.
基金contributes partly to the fulfillment of a National Project of Social Science entitled:A contrastive study of minimum discourse patterns in English and Chinese, coded 10BYY006an MOE project A contrastive study of clause relations and discourse patterns in English and Chinese, coded 08JA740013
文摘This study investigated how advanced Chinese students of English construct clause relations when construing English texts. A deconstructed text was distributed in class to 42 graduate students of linguistics, who were required to organize the clauses into a conceivably good text. The result suggests that these students seemed to rely on explicit cohesive words （anaphoric references and repetitions） rather than meaning relations in text construction. They seemed to have difficulties in using cataphoric contextual information and the popular discourse pattern from general to specific. This study calls for an enhanced awareness of logico-semantic relations in teaching and learning text construction.
文摘Various government documents tend to put the reordering of relationship together with institutional reform and functional transformation.If we fail to understand this important issue,we will be unable to understand China’s national governance system.The reordering of relationship has four dimensions:government and market;central and local government;the economy and society;and government and society.The routes to this reordering can be divided into separation,retention and postponement.On the one hand,the conflicts between these routes have affected China’s national governance structure,so that it seeks a balance between closure and opening up;on the other,the course taken by the reordering of relationship is rooted in the demands for generality and modernity that coexist within China’s national governance.One could say that the straightening out of relationship has reshaped the distinctive features of this governance.In the course of continuous reordering,some of its important elements have undergone a crucial change.From the perspective of the reordering of relationship,the openness with which these relations have been absorbed into a larger system is crucial to the future transformation of China’s national governance.
文摘Semantic Web has emerged to make web content machine-readable,and with the rapid increase in the number of web pages,its importance has increased.Resource description framework(RDF)is a special data graph format where Semantic Web data are stored and it can be queried by SPARQL query language.The challenge is to find the optimal query order that results in the shortest period of time.In this paper,the discrete Artificial Bee Colony(dABCSPARQL)algorithm is proposed,based on a novel heuristic approach,namely reordering SPARQL queries.The processing time of queries with different shapes and sizes is minimized using the dABCSPARQL algorithm.The performance of the proposed method is evaluated on chain,star,cyclic,and chain-star queries of different sizes from the Lehigh University Benchmark(LUBM)dataset.The results obtained by the proposed method are compared with those of ARQ(a SPARQL processor for Jena)query engine,the Ant System,the Elitist Ant System,and MAX-MIN Ant System algorithms.The experiments demonstrate that the proposed method significantly reduces the processing time,and in most queries,the reduction rate is higher compared with other optimization methods.
基金Project supported by the National Natural Science Foundation of China （No. 61102135）, the Fundamental Research Funds for the Central Universities, China （No. 2010121063）, and the Science and Technique Commission Foundation of Fujian Province, China （No. 2011 H6028）
文摘Geometry based block partitioning （GBP） has been shown to achieve better performance than the tree structure based block partitioning （TSBP） of H.264. However, the residual blocks of GBP mode after motion compensation still present some non-vertical/non-horizontal orientations, and the conventional discrete cosine transform （DCT） may generate many high-frequency coefficients. To solve this problem, in this paper we propose a video coding approach by using GBP and reordering DCT （RDCT） techniques. In the proposed approach, GBP is first applied to partition the macroblocks. Then, before performing DCT, a reordering operation is used to adjust the pixel positions of the residual macroblocks based on the partition information. In this way, the partition information of GBP can be used to represent the reordering information of RDCT, and the bitrate can be reduced. Experimental results show that, compared to H.264/AVC, the proposed method achieves on average 6.38% and 5.69% bitrate reductions at low and high bitrates, respectively.
基金supported by the National Natural Science Foundation of China(82371089).
文摘Objective:To evaluate the performance of orthokeratology(ortho-k)lens reordering using software-designed system,so as to determine the feasibility of ortho-k lens reordering without discontinuing lens wear.Methods:This study is a retrospective analysis of data of ortho-k lens wearers who had a history of short-term discontinuation of lens wear.A total of 94 individuals aged over 8 years with spherical equivalent refraction ranging from-0.50 to-6.50 diopters were included.The corneal topography data at baseline(before ortho-k)and after lens wear discontinuation(cessation of ortho-k treatment)were imported separately into the lens-design software,along with corresponding refraction data.Subsequently,corneal and lens parameters were generated and compared.Intraclass correlation coefficients(ICC)were calculated,and Bland and Altman analyses were conducted.Results:All 94 children were involved in the retrospective analysis.Compared with baseline data,there was a high level of consistency between Rwo(without discontinuation)and Rwith(with discontinuation),with an ICC of 0.96(P<0.001).Furthermore,the comparison of lens parameters generated by the Easyfit software between baseline and after short-term discontinuation showed a high degree of consistency,with all of the ICC values exceeding 0.90.Similar results were obtained using the WAVE software,as both ICC values and Bland-Altman plots demonstrated a high level of consistency in lens parameters between two conditions(nearly all data points fell within the 95%LoAs).Conclusions:It is feasible to directly reorder new ortho-k lenses using software fitting approaches.However,further investigations are necessary to validate their practicability in a clinical setting.
文摘随着人工智能生成内容技术的迅猛发展和大语言模型(large language models,LLMs)广泛应用,智算中心的网络面临着严峻挑战,流量控制是优化网络性能的重要方法.综述细粒度流量控制领域的关键问题及解决方案,重点梳理了自适应负载均衡机制、主动式拥塞控制机制和乱序包重排机制3个方面的研究进展.自适应负载均衡能够有效规避网络内部的拥塞,主动式拥塞控制用于预防自适应负载均衡无法避免的最后一跳拥塞问题,而乱序包重排解决了自适应负载均衡过程中可能引发的数据包乱序问题,三者协同作用确保了网络在高负载、高延迟等复杂环境下的稳定性与高效性.在此基础上,阐述了当前主流智算中心采用的关键技术方案以及目前支持细粒度流量控制的网络设备,最后总结了该领域尚未解决的关键问题及可能的解决方案,并对未来发展趋势进行了展望.
文摘远程直接内存访问(RDMA)已经成为数据中心网络(DCN)跨节点高性能数据传输的关键技术。但是,现有的RDMA传输协议,如基于融合以太网的RDMA版本2(RDMA over Converged Ethernet version 2,RoCEv2),仅支持顺序数据包处理。为进一步提高数据传输的灵活性,支持多路径传输与选择性重传,如何使RDMA网卡处理乱序数据包成为当下的研究热点。本文总结了RDMA乱序数据包的产生原因与处理方法,同时对涉及的相关技术如数据包排序、乱序数据包直写、位图管理、丢包检测、跨工作队列元素(WQE)的内存一致性、路径选择等进行了介绍。
