第八届国际海洋离岸与极地工程大会简况及一点感识

1．会议概况第八届国际海洋高岸与极地工程大会（The8th（1998）InternationalOffshoreandPolarEngineeringConference（ISOPE－98））于1998年5月24日～5月29日在加拿大Montreal召开．会议是由国际海洋离岸与极地工程师协会（ISOPE）会同大会技术委员会（TPC）及包括中国...

A high pressure xenon time projection chamber for double beta decay

This thesis describes the design, construction and performance of a high-pressure, xenon, gas time projection chamber (TPC) for the study of double beta decay in ^(136) Xe. The TPC when operating at 5 atm can accommodate 28 moles of 60% enriched ^(136) Xe. The TPC has operated as a detector at Caltech since 1986. It is capable of reconstructing a charged particle trajectory and can easily distinguish between different kinds of charged particles. A gas purification and xenon gas recovery system were developed. The electronics for the 338 channels of readout was developed along with a data acquistion system. Currently, the detector is being prepared at the University of Neuchatel for installation in the low background laboratory situated in the St. Gotthard tunnel, Switzerland. In one year of runtime the detector should be sensitive to a 0ν lifetime of the order of 10^(24) y, which corresponds to a neutrino mass in the range 0.3 to 3.3 eV.

Microbiological quality of some iced fishes of Imphal market, Manipur

Imphal is the main marketing centre of fish in Manipur. As fish production of the state is not sufficient to meet the demands, about 120 metric tons of iced fishes are annually brought from other states and sold in this market. Microbiological quality of iced Wallago attu, Labeo rohita, L. gonius and Aorichthy aor in respect of total fungal count (TFC), total plate count of bacteria (TPC), Most Probable Number (MPN) of coliforms, Streptococci, Staphylococcus, Salmonella and Escherichia coli in four tissues (skin, muscle, gill and intestine) were analysed. In all cases, the counts were highest in the gills and lowest in the muscles. The values of TFC, TPC, coliforms, Streptococci and Staphylococci were 0-10³/g 10(sup)6-10⁸/g, 2-α/g, 10-10⁵/g, 10-10⁵/g respectively. E. coli and Salmonella were not detected in any of the samples while the ice used in the preservation contained 10⁵-10⁷ of TPC per gram. The microbiological qualities of the iced fishes of Imphal market were adjudged poor. The extremely high counts of bacteria might be due to (1) poor quality and left over fishes being packed, (2) contact with contaminated ice and (3) repeated thawing and freezing during the process of marketing and transportation.

A method for the preparation of cooked-peeled-frozen prawns

Several consignments of cooked-peeled-frozen prawns exported from India were rejected last year due to high total plate count (TPC) at 30°C. The specified temperature of incubation for TPC in our country is 37°C. Hence the effect of incubation at 30 and 37°C on TPC was studied. It is seen that the count is higher on incubation at 30°C. A method for production of cooked-peeled-frozen prawns conforming to the specification for TPC at 30°C is standardized and is reported. It consists of recooking the cooked-peeled prawns followed by packing and freezing without further contamination. The method minimizes batch to batch or sample to sample variation in TPC.

Assessment of quality of fish landed at the Cochin fisheries harbour

Assessment of quality of fish and shrimps landed at the fish harbour, Cochin, was made over the period January, 1980 to December, 1982. A total of 201 samples were analysed. Nearly 75% of the samples scored between 6-10 in a 10 point hedonic scale and the percentage unacceptability based on sensory assessment was 5. 5%. In 10.1% of the samples, total volatile nitrogen was >30 mg% and in 8.3% of the samples trimethylamine- nitrogen was >10 mg%. Both, the gr Torrymeter and Intellectron Fish Tester VI readings marked significant correlation with sensory scores and chemical indices; but failed to bear any significant correlation with bacterial counts. Of the 5-1 total samples 66.7% had total plate count (TPC) ≥10 super(5) g super(-1) and 8.5% were considered unacceptable based on TPC >5x10 super(5) g super(-1); 63.2% of the samples were free from Escherichia coli; 26.4% had >20 E. coli g super(-1) and 20.4% of the samples contained faecal streptococci >10 super(3) g super(-1). Seven percent of the samples showed coagulase positive staphylococci >100 g super(-1). Salmonella could not be detected in any of the samples examined. Crushed ice samples and the platform of the harbour had high bacterial loads.

Allelopathic effects of phenolic compounds present in submerged macrophytes on Microcystis aeruginosa

In laboratory studies, the allelopathic effects of 3 (Hydrocharitaceae family) submerged macrophytes (Elodea nuttallii (Planch) St. John, Hydrilla verticillata (L.f.) Royle and Vallisneria spiralis L.) were investigated on two strains of Microcystis aeruginosa. Both aqueous methanol extracts and exudates of three macrophytes inhibited the growth of both strains of Microcystis aeruginosa, After 3-days culture, E nuttallii, H. verticillata and V. spiralis excreted 0.8, 0.3 and 1.0% of total phenolic compounds (TPC), respectively, into the surrounding water. After removing phenolic compounds by polyvinylpolypyrrolidone (PVPP)), the plant exudates showed very weak activity. The inhibitory rates of exudates of E. nuttallii, H. verticillata and V. spiralis, against non-toxic M. aeruginosa were decreased by 35.7, 43.4 and 59.1% respectively. Thus 3 submerged macrophytes released the phenolic compounds into the surrounding water, to inhibit the growth of M. aeruginosa. This information may help us in understanding the mechanism of allelopathy in aquatic ecosystems and to control the algal bloom in eutrophic water bodies.

Web容器性能关键技术研究

基于Java EE技术的Web容器已经成为面向Web计算环境的主流中间件平台，它为创建、部署、运行、集成和管理企业Web组件提供了基础设施支持。然而，企业用户规模的不断增长与企业Web应用程序的日趋复杂使得Web容器的性能面临严峻的威胁。 影响服务器性能的主要因素是服务器的资源与负载。在传统服务器设计领域，研究者已经取得了一系列的研究成果，如资源管理、准入控制、动态缓存、差分服务等。然而，上述传统服务器领域的研究成果难以满足开放、动态的Web计算环境需求。首先，Web容器无法预先获知企业Web应用程序的资源需求与负载特征，这使得它不得不采用一种“尽力而为”的服务策略。其次，传统资源管理技术难以解决不同资源之间的管理冲突，影响了资源的利用率。最后，传统的负载管理技术侧重于负载规模的变化，很少考虑负载的组成特征与行为特征。为解决上述问题，论文提出了一种面向资源的分阶段体系结构ROSA，并研究了基于ROSA的动态缓存技术与差分服务技术，具体研究内容如下： 论文首先提出了面向资源的分阶段体系结构ROSA，它将请求处理所需的处理资源（主要指线程）与共享资源加以区分，并且通过分阶段体系结构设计来有效解决处理资源阻塞。同时，论文扩展Petri网模型给出了ROSA体系结构的描述模型RDM与性能模型RPM，前者用于验证ROSA体系结构设计方案的结构性质与行为性质，后者用于定量的计算ROSA体系结构设计方案的平均响应时间、吞吐率等性能指标。最后，论文提出了相关设计模式用于ROSA体系结构的开发。 论文提出了一种访问模式驱动的动态缓存机制，消除了Web容器、Web组件与动态缓存机制的耦合，并能够利用客户访问模式提高Web容器的缓存效率。首先，论文设计了Web容器动态缓存框架来缓存Web组件动态生成的Web内容，减少Web组件的重复执行。然后，论文设计了模式图描述客户的访问行为，有效的消除了传统马尔可夫模型引入的无效访问行为。最后，论文在模式图基础上分别基于会话和缓存对象设计了两个预测概率函数以及访问模式驱动的缓存替换算法，有效的提高了动态缓存机制的效率。 论文提出了一种自适应差分服务机制以满足Web容器剧烈变化的负载，同时为企业Web应用程序的差分服务需求提供支持。首先，论文基于客户行为特征设计了动态的会话优先级，弥补了传统静态优先级定义（客户优先级、请求优先级）无法描述客户行为优先级的缺点。然后，通过扩展ROSA体系结构设计，提供了准入控制、优先级调度、资源预留等多种差分服务策略，从而适应Web容器的不同负载。最后，论文设计了自适应差分服务策略选择算法，根据Web容器负载状况自适应选择差分服务策略，消除了单一差分服务策略在某些情况下出现的资源浪费、请求“饿死”、不必要的请求丢失现象，保障了关键请求的性能指标。 最后，以上研究成果已经应用在一个高性能的Web容器系统Once Web容器中。在Java EE性能测试基准TPC-W的测试中取得了较好的效果。

面向服务质量的电子商务运行平台测试基准的设计与实现

电子商务是一种新兴的企业运作模式。随着Internet相关技术的高速发展，电子商务企业面临着前所未有的发展机遇。与此同时，电子商务企业竞争也日益激烈，电子商务应用的服务质量成为竞争的焦点所在。电子商务应用通常基于更为基础的运行平台来构建，如应用服务器等，这些运行平台对其服务质量的保障至关重要，如何评价这些运行平台的服务质量保障能力是特别需要关注的研究问题。 测试基准因为其设计的典型性以及评价的公正性，逐渐成为电子商务企业青睐的评价手段。然而目前主流的电子商务运行平台测试基准，主要关注以吞吐量为主的峰值性能度量，而没有考虑到电子商务应用具有较为独特的业务特征，如用户对服务质量敏感而引起的行为变化，以及难以使用孤立的性能指标描述的业务特征，如会话完成情况和商业利益等。这使得目前这些测试基准并不能准确评价运行平台的服务质量保障能力。 论文分析了现有的电子商务运行平台测试基准，指出了这些测试基准，如TPC-W在评价运行平台服务质量保障能力方面的不足，提出一种面向服务质量的电子商务运行平台测试基准——Bench4Q。相比于目前测试基准普遍采用的封闭式负载仿真模式，Bench4Q采用一种开放的负载生成方式，以用户会话为核心来组织负载生成，真实可控，可以模拟更加真实的Internet负载； Bench4Q还增加了用户对服务质量的反应，增加了用户容忍度的设计，模拟了更真实的用户行为，使得测试结果更真实有效；与此同时，Bench4Q重点衡量会话完成情况，体现业务收益，关注系统的服务质量保障能力，全面衡量电子商务系统的表现。 同时，本文给出了一种面向服务质量的电子商务运行平台的测试基准的设计方案，并按照设计方案实现了Bench4Q测试工具。通过使用该测试工具对一些典型场景的测试，说明与传统的性能测试基准相比，Bench4Q能够更加准确地评价运行平台对电子商务应用的服务质量保障能力。

HPLUS前角区径迹探测器的设计和模拟

在HIRFL-CSR上筹建的兰州强子谱仪（HPLUS）中，前角区径迹探测器（FTD）对于粒子鉴别以及系统的触发都是非常重要的部分之一。计划中的FTD是由五块平面型的多丝漂移室组成，主要用来测量在前角区出射的带电粒子的径迹 （和能损），实现粒子动量测量和粒子鉴别，而联合其它探测器（如TOF和TPC）则可能提高由于取样数限制的粒子鉴别。实现探测器构型的优化和对拟建装置上物理目标的可行性预研是模拟工作的重要目的。快模拟是对拟建装置进行快速优化的有效方法。在Geant4环境对拟建装置的细致模拟，是进一步优化探测器结构、充分的估计探测器整体性能的必要步骤，为将来的谱仪的制造和可能的物理实验提供可靠的参考。 本论文的主要工作包括以下两个方面。（1）在HPLUS概念设计的基础上，发展了局域化的多径迹查找和径迹重建算法，对产物在前角区分布的典型反应道pp→pp+φ(→K+K-)进行了可行性预研，得到FTD对φ的几何覆盖率为83.5%，由于漂移室空间分辨对的动量分辨的贡献为1.3%，并在考虑了本底道pp→pp+K+K-的影响下，重建了φ的不变质量谱，得到φ峰宽度和信噪比分别为1.51MeV和4.36。在考虑到前角区径迹探测器的占有空间和探测要求的情况下对HPLUS构型做出了一定的优化，为全模拟提供了一组FTD参数。（2）基于快模拟得到的参数和参考了PANDA探测器漂移室的情况下，完成了FTD的初步设计并对其中的物质分布进行了预算，通过经验公式得到FTD的空间分辨和多次散射对K+动量分辨的贡献为1.34%和0.34%。在HPLUS模拟平台上，用GDML语言完成了对前角区径迹探测器的构建

Evaluation of 28 marine algae from the Qingdao coast for antioxidative capacity and determination of antioxidant efficiency and total phenolic content of fractions and subfractions derived from Symphyocladia latiuscula (Rhodomelaceae)

The extracts obtained from 28 species of marine algae were evaluated for their antioxidant activity (AA) versus the positive controls butylated hydroxytoluene (BHT), gallic acid (GA), and ascorbic acid (AscA). Most of the tested samples displayed antioxidant activity to various degrees. Among them, the extract of Symphyocladia latiuscula exhibited the strongest AA, which was comparable to BHT, GA, and AscA in radical scavenging activity, as shown in the DPPH (alpha,alpha-diphenyl-beta-picrylhydrazyl) assay, and higher than those of the positive controls in beta-carotene-linoleate assay system. In addition, the ethyl acetate-soluble fraction isolated from the crude extract of S. latiuscula exhibited the highest antioxidant activity in both assay systems. This fraction was further fractionated into seven subfractions (F1-F7) by vacuum liquid chromatography (VLC). F1 and F4 were found to be the most effective subfractions in scavenging DPPH radical assay and in the beta-carotene-linoleate assay, respectively. The total phenolic content (TPC) and reducing power (RP) for all of the extracts, fractions, and subfractions (F1-F7) were also determined. The TPC of the 28 extracts ranged from 0.10 to 8.00 gallic acid equivalents (mg/g seaweed dry weight) while the RP ranged from 0.07 to 11.60 ascorbic acid equivalents (mg center dot g(-1) seaweed dry weight). Highly positive relationships between AA and TPC as well as between AA and RP were found for the extracts and fractions, while for the subfractions F1-F7 only weak or no such relations were found. The results obtained from this study indicate that further analysis is needed of those marine algal species that contain the most antioxidant activity in order to identify the active principles.

北京中小学生创造性思维的发展以及十三年前后之比较

This study investigated the major characteristics of creative thinking development for the school children in Beijing with paper/pencil tests. The “Creative Thinking Test” was executed. The representative samples were two groups of students who came from the classes in 3rd-grade to 12th-grade of normal schools in Beijing. The classes were selected at random, one grade one class. One group is composed of 387 students (218 males, 169 females) in 1993, the other is composed of 420 students (181 males, 239 females) in 2006. According to the data analysis, the major characteristics and the changes over the 13 years of the development of creative thinking for student were explored and discussed. 1) The development trends of three types of creative thinking were all flexuous increase with grade moving up. The mean score of elementary school students was the lowest. And scores of junior high school students and senior high school students were significant higher than elementary school students’. 2) The most rapid increase occurred from the 5th grade to 6th grade. 3) Slumps occurred in the 7th grade in PNE curve and also in the 9th and 12th grades in TPC curves. There was no slump in FGA curve. 4) The girl’s scores in PNE and TPC tests were significant better than boys’. No obvious gender difference was found in FGA test. 5) The scores of three creative thinking tests in 2006 were all better than those in 1993. Separately, the scores of FGA and TPC tests in 2006 were significant higher than the corresponding scores in 1993, and no significant difference was found in two PNE tests. 6) There was no significant difference in the maximum scores of the three creative thinking tests between 2006 and 1993. 7) The most rapid developing period of three types of creative thinking in 2006 were the 5th grade and the 6th grade. The same period in 1993 was from the 7th grade to 9th grade. 8) In 1993, there is no significant gender difference for each creative thinking test. In 2006, PNE and TPC results had remarkable gender difference that girls were higher than boys. No significant gender difference was found in FGA tests.

Vector Associative Maps: Unsupervised Real-time Error-based Learning and Control of Movement Trajectories

This article describes neural network models for adaptive control of arm movement trajectories during visually guided reaching and, more generally, a framework for unsupervised real-time error-based learning. The models clarify how a child, or untrained robot, can learn to reach for objects that it sees. Piaget has provided basic insights with his concept of a circular reaction: As an infant makes internally generated movements of its hand, the eyes automatically follow this motion. A transformation is learned between the visual representation of hand position and the motor representation of hand position. Learning of this transformation eventually enables the child to accurately reach for visually detected targets. Grossberg and Kuperstein have shown how the eye movement system can use visual error signals to correct movement parameters via cerebellar learning. Here it is shown how endogenously generated arm movements lead to adaptive tuning of arm control parameters. These movements also activate the target position representations that are used to learn the visuo-motor transformation that controls visually guided reaching. The AVITE model presented here is an adaptive neural circuit based on the Vector Integration to Endpoint (VITE) model for arm and speech trajectory generation of Bullock and Grossberg. In the VITE model, a Target Position Command (TPC) represents the location of the desired target. The Present Position Command (PPC) encodes the present hand-arm configuration. The Difference Vector (DV) population continuously.computes the difference between the PPC and the TPC. A speed-controlling GO signal multiplies DV output. The PPC integrates the (DV)·(GO) product and generates an outflow command to the arm. Integration at the PPC continues at a rate dependent on GO signal size until the DV reaches zero, at which time the PPC equals the TPC. The AVITE model explains how self-consistent TPC and PPC coordinates are autonomously generated and learned. Learning of AVITE parameters is regulated by activation of a self-regulating Endogenous Random Generator (ERG) of training vectors. Each vector is integrated at the PPC, giving rise to a movement command. The generation of each vector induces a complementary postural phase during which ERG output stops and learning occurs. Then a new vector is generated and the cycle is repeated. This cyclic, biphasic behavior is controlled by a specialized gated dipole circuit. ERG output autonomously stops in such a way that, across trials, a broad sample of workspace target positions is generated. When the ERG shuts off, a modulator gate opens, copying the PPC into the TPC. Learning of a transformation from TPC to PPC occurs using the DV as an error signal that is zeroed due to learning. This learning scheme is called a Vector Associative Map, or VAM. The VAM model is a general-purpose device for autonomous real-time error-based learning and performance of associative maps. The DV stage serves the dual function of reading out new TPCs during performance and reading in new adaptive weights during learning, without a disruption of real-time operation. YAMs thus provide an on-line unsupervised alternative to the off-line properties of supervised error-correction learning algorithms. YAMs and VAM cascades for learning motor-to-motor and spatial-to-motor maps are described. YAM models and Adaptive Resonance Theory (ART) models exhibit complementary matching, learning, and performance properties that together provide a foundation for designing a total sensory-cognitive and cognitive-motor autonomous system.

Novel ingredients from brewers' spent grain - bioactivity in cell culture model systems and bioactivity retention in fortified food products

Functional food ingredients, with scientifically proven and validated bioactive effects, present an effective means of inferring physiological health benefits to consumers to reduce the risk of certain diseases. The search for novel bioactive compounds for incorporation into functional foods is particularly active, with brewers’ spent grain (BSG, a brewing industry co-product) representing a unique source of potentially bioactive compounds. The DNA protective, antioxidant and immunomodulatory effects of phenolic extracts from both pale (P1 - P4) and black (B1 – B4) BSG were examined. Black BSG extracts significantly (P < 0.05) protected against DNA damage induced by hydrogen peroxide (H2O2) and extracts with the highest total phenolic content (TPC) protected against 3-morpholinosydnonimine hydrochloride (SIN-1)-induced oxidative DNA damage, measured by the comet assay. Cellular antioxidant activity assays were used to measured antioxidant potential in the U937 cell line. Extracts P1 – P3 and B2 - B4 demonstrated significant (P < 0.05) antioxidant activity, measured by the superoxide dismutase (SOD) activity, catalase (CAT) activity and gluatathione (GSH) content assays. Phenolic extracts P2 and P3 from pale BSG possess anti-inflammatory activity measured in concanavalin-A (conA) stimulated Jurkat T cells by an enzyme-linked immunosorbent assay (ELISA); significantly (P < 0.05) reducing production of interleukin-2 (IL-2), interleukin-4 (IL-4, P2 only), interleukin-10 (IL-10) and interferon-γ (IFN-γ). Black BSG phenolic extracts did not exhibit anti-inflammatory effects in vitro. Hydroxycinnamic acids (HA) have previously been shown to be the phenolic acids present at highest concentration in BSG; therefore the HA profile of the phenolic extracts used in this research, the original barley (before brewing) and whole BSG was characterised and quantified using high performance liquid chromatography (HPLC). The concentration of HA present in the samples was in the order of ferulic acid (FA) > p-coumaric acid (p-CA) derivatives > FA derivatives > p-CA > caffeic acid (CA) > CA derivatives. Results suggested that brewing and roasting decreased the HA content. Protein hydrolysates from BSG were also screened for their antioxidant and anti-inflammatory potential. A total of 34 BSG protein samples were tested. Initial analyses of samples A – J found the protein samples did not exert DNA protective effects (except hydrolysate H) or antioxidant effects by the comet and SOD assays, respectively. Samples D, E, F and J selectively reduced IFN-γ production (P < 0.05) in Jurkat T cells, measured using enzyme linked immunosorbent assay (ELISA). Further testing of hydrolysates K – W, including fractionated hydrolysates with molecular weight < 3, < 5 and > 5 kDa, found that higher molecular weight (> 5 kDa) and unfractionated hydrolysates demonstrate greatest anti-inflammatory effects, while fractionated hydrolysates were also shown to have antioxidant activity, by the SOD activity assay. A commercially available yogurt drink (Actimel) and snack-bar and chocolate-drink formulations were fortified with the most bioactive phenolic and protein samples – P2, B2, W, W < 3 kDa, W < 5 kDa, W > 5 kDa. All fortified foods were subjected to a simulated gastrointestinal in vitro digestion procedure and bioactivity retention in the digestates was determined using the comet and ELISA assays. Yogurt fortified with B2 digestate significantly (P < 0.05) protected against H2O2-induced DNA damage in Caco-2 cells. Greatest immunomodulatory activity was demonstrated by the snack-bar formulation, significantly (P < 0.05) reducing IFN-γ production in con-A stimulated Jurkat T cells. Hydrolysate W significantly (P < 0.05) increased the IFN-γ reducing capacity of the snack-bar. Addition of fractionated hydrolysate W < 3 kDa and W < 5 kDa to yogurt also reduced IL-2 production to a greater extent than the unfortified yogurt (P < 0.05).

Access Point Association Coordination in Densely Deployed 802.11 Wireless Networks

Dense deployment of wireless local area network (WLAN) access points (APs) is an important part of the next generation Wi-Fi and standardization (802.11ax) efforts are underway. Increasing demand for WLAN connectivity motivates such dense deployments, especially in geographical areas with large numbers of users, such as stadiums, large enterprises, multi-tenant buildings, and urban cities. Although densification of WLAN APs guarantees coverage, it is susceptible to increased interference and uncoordinated association of stations (STAs) to APs, which degrade network throughput. Therefore, to improve network throughput, algorithms are proposed in this thesis to optimally coordinate AP associations in the presence of interference. In essence, coordination of APs in dense WLANs (DWLANs) is achieved through coordination of STAs' associations with APs. While existing approaches suggest tuning of APs' beacon powers or using transmit power control (TPC) for association control, here, the signal-to-interference-plus-noise ratio (SINRs) of STAs and the clear channel assessment (CCA) threshold of the 802.11 MAC protocol are employed. The proposed algorithms in this thesis enhance throughput and minimize coverage holes inherent in cell breathing and TPC techniques by not altering the transmit powers of APs, which determine cell coverage. Besides uncoordinated AP associations, unnecessary frequent transmission deferment is envisaged as another problem in DWLANs due to the clear channel assessment aspect of the carrier sensing multiple access collision avoidance (CSMA/CA) scheme in 802.11 standards and the short spatial reuse distance between co-channel APs. To address this problem in addition to AP association coordination, an algorithm is proposed for CCA threshold adjustment in each AP cell, such that CCA threshold used in one cell mitigates transmission deferment in neighboring cells. Performance evaluation reveals that the proposed association optimization algorithms achieve significant gain in throughput when compared with the default strongest signal first (SSF) association scheme in the current 802.11 standard. Also, further gain in throughput is observed when the CCA threshold adjustment is combined with the optimized association. Results show that when STA-AP association is optimized and CCA threshold is adjusted in each cell, throughput improves. Finally, transmission delay and the number of packet re-transmissions due to collision and contention significantly decrease.

WIQ:Work-intensive query scheduling for in-memory database systems

We propose a novel admission control policy for database queries. Our methodology uses system measurements of CPU utilization and query backlogs to determine interference between queries in execution on the same database server. Query interference may arise due to the concurrent access of hardware and software resources and can affect performance in positive and negative ways. Specifically our admission control considers the mix of jobs in service and prioritizes the query classes consuming CPU resources more efficiently. The policy ignores I/O subsystems and is therefore highly appropriate for in-memory databases. We validate our approach in trace-driven simulation and show performance increases of query slowdowns and throughputs compared to first-come first-served and shortest expected processing time first scheduling. Simulation experiments are parameterized from system traces of a SAP HANA in-memory database installation with TPC-H type workloads. © 2012 IEEE.