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Optimization of thread partitioning parameters in speculative multithreading based on artificial immune

Yu-xiang LI,Yin-liang ZHAO,Bin LIU,Shuo JI

《信息与电子工程前沿（英文）》 2015年第16卷第3期页码 205-216 doi: 10.1631/FITEE.1400172

摘要： Thread partition plays an important role in speculative multithreading (SpMT) for automatic parallelization of irregular programs. Using unified values of partition parameters to partition different applications leads to the fact that every application cannot own its optimal partition scheme. In this paper, five parameters affecting thread partition are extracted from heuristic rules. They are the dependence threshold (DT), lower limit of thread size (TSL), upper limit of thread size (TSU), lower limit of spawning distance (SDL), and upper limit of spawning distance (SDU). Their ranges are determined in accordance with heuristic rules, and their step-sizes are set empirically. Under the condition of setting speedup as an objective function, all combinations of five threshold values form the solution space, and our aim is to search for the best combination to obtain the best thread granularity, thread dependence, and spawning distance, so that every application has its best partition scheme. The issue can be attributed to a single objective optimization problem. We use the artificial immune algorithm (AIA) to search for the optimal solution. On Prophet, which is a generic SpMT processor to evaluate the performance of multithreaded programs, Olden benchmarks are used to implement the process. Experiments show that we can obtain the optimal parameter values for every benchmark, and Olden benchmarks partitioned with the optimized parameter values deliver a performance improvement of 3.00% on a 4-core platform compared with a machine learning based approach, and 8.92% compared with a heuristics-based approach.

关键词： Speculative multithreading Thread partitioning Artificial immune algorithm

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Kd-tree and quad-tree decompositions for declustering of 2D range queries over uncertain space

Ahmet SAYAR,Süleyman EKEN,Okan ÖZTÜRK

《信息与电子工程前沿（英文）》 2015年第16卷第2期页码 98-108 doi: 10.1631/FITEE.1400165

摘要： We present a study to show the possibility of using two well-known space partitioning and indexing techniques, kd trees and quad trees, in declustering applications to increase input/output (I/O) parallelization and reduce spatial data processing times. This parallelization enables time-consuming computational geometry algorithms to be applied efficiently to big spatial data rendering and querying. The key challenge is how to balance the spatial processing load across a large number of worker nodes, given significant performance heterogeneity in nodes and processing skews in the workload.

关键词： Kd tree Quad tree Space partitioning Spatial indexing Range queries Query optimization

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Partitioning of heavy metals during municipal solid waste incineration on a laboratory fluid bed furnace

LI Jianxin, YAN Jianhua, CHI Yong

《能源前沿（英文）》 2007年第1卷第3期页码 359-364 doi: 10.1007/s11708-007-0054-2

摘要： The content of heavy metals in the main physical compositions of municipal solid waste (MSW) is analyzed. The effects of temperature, chlorine and water on the partitioning of heavy metals are studied using a laboratory fluidized-bed (FB) furnace with simulated MSW composition. The experimental results show that temperature and chloride content in the feed have significant influence on the volatility of heavy metals, especially those of lower boiling point such as Hg, Cd and Zn. The influence of water is slight.

关键词： partitioning municipal volatility significant influence temperature

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Particulate matter and metals partitioning in highway rainfall-runoff

Gaoxiang YING, John J. SANSALONE,

《环境科学与工程前沿（英文）》 2010年第4卷第1期页码 35-46 doi: 10.1007/s11783-010-0009-4

摘要： This study investigated the particulate matter (PM) and metals in highway dry deposition and rainfall-runoff as a function of hydrologic transport and settling on an event basis. Events were differentiated as mass-limited (ML) and flow-limited (FL). Results indicate that unique and separate suspended sediment concentration (SSC) relationships with turbidity occurred for ML and FL events. Sixty minutes of quiescent settling produced a single SSC-turbidity relationship for all events. ML events transport higher proportions of settleable and sediment PM while FL events transported relatively higher suspended PM. For batch clarification with one hour of settling, ML events had generally higher treatment efficiencies compared to FL events for the same settling conditions. Highway dry deposition PM was hetero-disperse and coarse ( = 304 µm). Results indicate that the acidic rainfall is not a significant contributor to metals in runoff but is capable of leaching metals from dry deposition PM into runoff. Partitioning in retained runoff resulted in a particulate-bound €predominance €for €most €metals €except Ca and Mg. While the finer fraction of dry deposition PM (<75µm) generates the highest metal concentrations, the highest metal mass is associated with the coarser fraction (>75µm).

关键词： stormwater particulate matter (PM) turbidity suspended sediment concentration (SSC) unit operations metals dry deposition acid rain

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Comparison of evapotranspiration and energy partitioning related to main biotic and abiotic controllers

Lei GAO, Peng ZHAO, Shaozhong KANG, Sien LI, Ling TONG, Risheng DING, Hongna LU

《农业科学与工程前沿（英文）》 2020年第7卷第4期页码 490-504 doi: 10.15302/J-FASE-2019310

摘要：

Knowledge of evapotranspiration (ET) and energy partitioning is useful for optimizing water management, especially in areas where water is scarce. A study was undertaken in a furrow-irrigated vineyard (2015) and a drip-irrigated vineyard (2017) in an arid region of north-west China to compare vineyard ET and energy partitioning and their responses to soil water content (SWC) and leaf area index (LAI). ET and soil evaporation (E) and transpiration (T) were determined using eddy covariance, microlysimeters, and sap flow. Seasonal average E/ET, T/ET, crop coefficient (Kc), evaporation coefficient (Ke), and basal crop coefficient (Kcb) were 0.50, 0.50, 0.67, 0.35, and 0.29, respectively, in the furrow-irrigated vineyard and 0.42, 0.58, 0.57, 0.29, and 0.43 in the drip-irrigated vineyard. The seasonal average partitioning of net radiation (Rn) into the latent heat flux (LE), sensible heat flux (H) and soil heat flux (G) (LE/Rn, H/Rn, and G/Rn), evaporative fraction (EF) and Bowen ratio (β) were 0.57, 0.26, 0.17, 0.69 and 0.63, respectively, in the furrow-irrigated vineyard and 0.46, 0.36, 0.17, 0.57 and 0.97 in the drip-irrigated vineyard. The LE/Rn, H/Rn, EF, and β were linearly correlated with LAI. The E, Kc, Ke, E/ET, LE/Rn, LEs/Rn (ratio of LE by soil E to Rn), H/Rn, EF and β were closely correlated with topsoil SWC (10 cm depth). Responses of ET and energy partitioning to the LAI and SWC differed under the two irrigation methods. Drip irrigation reduced seasonal average E/ET and increased average T/ET. From the perspective of energy partitioning, seasonal average H/Rn increased whereas LE/Rn, especially LEs/Rn, decreased. Compared with furrow irrigation, drip irrigation decreased the proportion of unproductive water consumption thereby contributing to enhanced water use efficiency and accumulation of dry matter.

关键词： crop coefficient eddy covariance microlysimeter sap flow soil evaporation transpiration

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两相分配生物反应器——浊点系统在生物转化中的应用

王志龙

《中国工程科学》 2005年第7卷第5期页码 73-78

摘要：

利用两相分配生物反应器可以控制底物由非水相向水相释放，增加底物的溶解度和解除底物对微生物的抑制，保护产物降解，降低下游分离费用；论述了两相分配生物反应器的基本原理和发展概况，并以胆固醇边链切除生物转化为例，介绍了新开发的浊点系统两相分配生物反应器的巨大潜力。

关键词：两相分配生物转化非离子表面活性剂浊点系统生物反应器

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干旱和复水对冬小麦光合产物分配格局的影响

谷艳芳,丁圣彦,高志英,邢倩

《中国工程科学》 2012年第14卷第3期页码 59-64

摘要：

于2005—2006年在中国科学院封丘农田生态实验站研究了不同水分处理下冬小麦光合产物分配格局及其动态。实验设全生育期干旱处理和充分供水处理以及干旱后拔节期、孕穗期、开花期复水处理。结果显示：不同生育期复水对冬小麦由于干旱胁迫引起的生物量下降有补偿作用；干旱和复水能改变器官水平上光合产物的分配格局；干旱胁迫引起叶、穗分配降低，并使茎、叶鞘和根分配指数上升；拔节期复水使叶光合产物分配指数增加、茎分配指数下降；孕穗期和开花期复水能提高光合产物在茎和穗中的分配；不同时期复水对干旱胁迫引起的产量下降均有不同程度的补偿作用，拔节期复水主要提高小麦单株穗数、孕穗期和开花期复水以提高千粒重为主。

关键词：光合产物分配指数可溶性糖冬小麦干旱和复水

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The “Tiangong” Chinese Space Station project

Yang HONG

《工程管理前沿（英文）》 2018年第5卷第2期页码 278-283 doi: 10.15302/J-FEM-2018202

关键词： manned space station space station project basic design

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Application and development of modern long-span space structures in China

Shilin DONG, Yang ZHAO, Dong XING

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 224-239 doi: 10.1007/s11709-012-0166-6

摘要： Modern long-span space structures, developed during the 1970s and 1980s, are light and effective structures based on new technologies and light-weight high-strength materials, such as membranes and steel cables. These structures include air-supported membrane structures, cable-membrane structures, cable truss structures, beam string structures, suspen-domes, cable domes, composite structures of cable dome and single-layer lattice shell, Tensairity structures and so forth. For the premodern space structures widely used since the mid-twentieth century (such as thin shells, space trusses, lattice shells and ordinary cable structures), new space structures have been developed by the combination of different structural forms and materials. The application of prestressing technology and the innovation of structural concepts and configurations are also associated with modern space structures, including composite space trusses, open-web grid structures, polyhedron space frame structures, partial double-layer lattice shells, cable-stayed grid structures, tree-type structures, prestressed segmental steel structures and so forth. This paper provides a review of the structural characteristics and practical applications in China of modern rigid space structures, modern flexible space structures and modern rigid-flexible combined space structures.

关键词： modern long-span space structures rigid space structures flexible space structures rigid-flexible combined space structures application and development

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统筹空间科学、空间技术、空间应用协调发展的思考

周建平,吴季

《中国工程科学》 2023年第25卷第2期页码 59-66 doi: 10.15302/J-SSCAE-2023.02.007

摘要：

我国航天事业因历史原因和投入限制，在初期以空间技术、空间应用为主，对空间科学重视不足，空间科学、空间技术、空间应用基本上是独立发展的；着眼新时期航天强国建设，需要将空间技术的发展深度融合到空间科学、空间应用中去，从而创造新的机遇和成就。本文剖析了空间科学、空间技术、空间应用的基本内涵并明确三者的相互关系，在系统分析国际空间科学、空间技术、空间应用的整体态势，细致梳理我国相关领域发展情况的基础上，论证了统筹我国空间科学、空间技术、空间应用协调发展的必要性，凝练了三者协调发展面临的主要问题。空间科学、空间技术、空间应用之间既有需求交叉，又可互促带动，应在规划、部署、实施的全过程中进行统筹考虑：发挥新型举国体制优势，在统一管理下做好顶层规划；坚持创新驱动发展战略，以技术进步抢占国际航天制高点；支持空间领域基础研究，培育高水平的科学家和工程师队伍；加强资源统筹协调，促进空间应用数据的合理开放和充分利用。

关键词：航天事业；空间科学；空间技术；空间应用；协调发展；数据开放共享

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空间物理和空间天气探测与研究

王赤

《中国工程科学》 2008年第10卷第6期页码 41-45

摘要：

空间物理学是1957年人造卫星发射成功后迅速发展起来的一门交叉学科。近50年来，空间已成为人类生存的第四环境，其重要性日益突出。20世纪90年代初，空间物理学与空间应用的密切结合产生了专门研究和预报空间环境中灾害性过程及其变化规律，减轻或防止空间灾害并为人类活动服务的空间天气学。文章简要总结了国外及国内空间物理和空间天气探测的历程和发展趋势，并提出对我国未来空间物理和空间天气探测发展规划和探测路线图的几点建议。

关键词：空间物理空间天气空间物理探测发展规划

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深空安全研究现状与未来发展

吴克,张哲,杨文飞,何建峰,张天柱,简抗抗,吴伟仁

《中国工程科学》 2022年第24卷第4期页码 240-248 doi: 10.15302/J-SSCAE-2022.04.023

摘要： Managing space radiation risk in the new era of space exploration [R].Managing space radiation risk in the new era of space exploration [R].Human space exploration the next fifty years [J].Human space exploration the next fifty years [J].Human space exploration the next fifty years [J].

关键词：深空安全空间辐射威胁行星保护太空遗产保护空间立法

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Reducing CO emissions from the rebalancing operation of the bike-sharing system in Beijing

《工程管理前沿（英文）》 2023年第10卷第2期页码 262-284 doi: 10.1007/s42524-021-0168-y

摘要： With the development of the bike-sharing system (BSS) and the introduction of green and low carbon development, the environmental impacts of BSS had received increasing attention in recent years. However, the emissions from the rebalancing of BSS, where fossil-fueled vehicles are commonly used, are usually neglected, which goes against the idea of green travel in a sharing economy. Previous studies on the bike-sharing rebalancing problem (BRP), which is considered NP-hard, have mainly focused on algorithm innovation instead of improving the solution model, thereby hindering the application of many existing models in large-scale BRP. This study then proposes a method for optimizing the CO₂ emissions from BRP and takes the BSS of Beijing as a demonstration. We initially analyze the spatial and temporal characteristics of BSS, especially the flow between districts, and find that each district can be independently rebalanced. Afterward, we develop a rebalancing optimization model based on a partitioning strategy to avoid deciding the number of bikes being loaded or unloaded at each parking node. We then employ the tabu search algorithm to solve the model. Results show that (i) due to over launch and lack of planning in rebalancing, the BSS in Beijing shows great potential for optimization, such as by reducing the number of vehicle routes, CO₂ emissions, and unmet demands; (ii) the CO₂ emissions of BSS in Beijing can be reduced by 57.5% by forming balanced parking nodes at the end of the day and decreasing the repetition of vehicle routes and the loads of vehicles; and (iii) the launch amounts of bikes in specific districts, such as Shijingshan and Mentougou, should be increased.

关键词： bike-sharing CO₂ emissions environmental benefit partitioning strategy rebalancing problem

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Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive

《化学科学与工程前沿（英文）》页码 1623-1631 doi: 10.1007/s11705-022-2202-y

摘要： The number of active components and their dispersion degree are two key factors affecting the performance of adsorbents. Here, we report a simple but efficient strategy for dispersing active components by using a confined space, which is formed by mesoporous silica walls and templates in the as-prepared SBA-15 (AS). Such a confined space does not exist in the conventional support, calcined SBA-15, which does not contain a template. The Cu and Zn precursors were introduced to the confined space in the AS and were converted to CuO and ZnO during calcination, during which the template was also removed. The results show that up to 5 mmol·g^–1 of CuO and ZnO can be well dispersed; however, severe aggregation of both oxides takes place in the sample derived from the calcined SBA-15 with the same loading. Confined space in the AS and the strong interactions caused by the abundant hydroxyl groups are responsible for the dispersion of CuO and ZnO. The bimetallic materials were employed for the adsorptive separation of propene and propane. The samples prepared from the as-prepared SBA-15 showed superior performance to their counterparts from the calcined SBA-15 in terms of both adsorption capacity of propene and selectivity for propene/propane.

关键词： bimetallic adsorbents confined space mesoporous silica propene/propane separation

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Corrosion damage assessment and monitoring of large steel space structures

Bo CHEN, You-Lin XU, Weilian QU,

《结构与土木工程前沿（英文）》 2010年第4卷第3期页码 354-369 doi: 10.1007/s11709-010-0088-0

摘要： Large steel space structures, when exposed to a harsh corrosive environment, are inevitably subjected to atmospheric corrosion and stress corrosion cracking. This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion. The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced. The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking. Based on the results, the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.

关键词： large steel space structure atmospheric corrosion stress corrosion cracking corrosion damage damage assessment monitoring system