Investigations of the mechanical response of dummy HTPB propellant grain under ultrahigh acceleration overload conditions using onboard flight-test measurements

In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.

An integrated split and dummy gates MOSFET with fast turn-off and reverse recovery characteristics

A power MOSFET with integrated split gate and dummy gate(SD-MOS) is proposed and demonstrated by the TCAD SENTAURUS.The split gate is surrounded by the source and shielded by the dummy gate.Consequently,the coupling area between the split gate and the drain electrode is reduced,thus the gate-to-drain charge(Q_(GD)),reverse transfer capacitance(C_(RSS)) and turn-off loss(E_(off)) are significantly decreased.Moreover,the MOS-channel diode is controlled by the dummy gate with ultra-thin gate oxide t_(ox),which can be turned on before the parasitic P-base/N-drift diode at the reverse conduction,then the majority carriers are injected to the N-drift to attenuate the minority injection.Therefore,the reverse recovery charge(Q_(RR)),time(T_(RR)) and peak current(I_(RRM)) are effectively reduced at the reverse freewheeling state.Additionally,the specific on-resistance(R_(on,sp)) and breakdown voltage(BV) are also studied to evaluate the static properties of the proposed SD-MOS.The simulation results show that the Q_(GD) of 6 nC/cm^(2),the C_(RSS) of 1.1 pF/cm^(2) at the V_(DS) of 150 V,the QRR of 1.2 μC/cm^(2) and the R_(on,sp) of 8.4 mΩ·cm^(2) are obtained,thus the figures of merit(FOM) including Q_(GD) ×R_(on,sp) of50 nC·mΩ,E_(off) × R_(on,sp) of 0.59 mJ·mΩ and the Q_(RR) × R_(on,sp) of 10.1 μC·mΩ are achieved for the proposed SD-MOS.

Detecting the One-Shot Dummy Attack on the Power Industrial Control Processes With an Unsupervised Data-Driven Approach

Dear Editor,Dummy attack(DA), a deep stealthy but impactful data integrity attack on power industrial control processes, is recently recognized as hiding the corrupted measurements in normal measurements. In this letter, targeting a more practical case, we aim to detect the oneshot DA, with the purpose of revealing the DA once it is launched.Specifically, we first formulate an optimization problem to generate one-shot DAs. Then, an unsupervised data-driven approach based on a modified local outlier factor(MLOF) is proposed to detect them.

BIOSID Dummy撞击实验的计算机模拟研究

给出了一个BIOSIDdummy侧撞有限元模拟结果 ,和实验结果比较验证后可知该模型是可靠有效的。这一模型不仅可以用于任何侧撞情况下车辆乘员损伤防护模拟的研究 。

Hybrid-Ⅲ型Dummy刚性有限元模型的研究改进

Hybrid-Ⅲ型Dummy刚性有限元模型因具有独特的优点已被广泛地用于评定汽车乘员安全系统有效性的模拟研究中。在汽车安全带的模拟中发现现有模型存在较大的缺陷。本文提供了一个改进模型,利用实验结果验证,改进模型是合理有效的。该模型可为乘员安全保护系统的评估提供更为精确的模拟结果。

EUROSID-I Dummy的结构及有限元模型

描述了ＥＵＲＯＳＩＤ－Ｉ型ｄｕｍｍｙ的结构及有限元模型，以便对该ｄｕｍｍｙ进行计算机模拟。该模型不仅可用于各种侧向撞击的研究，也可用于ｄｕｍｍｙ的改进和发展。

EUROSID-Ⅰ型Dummy的计算机模拟

在介绍了ＥＵＲＯＳＩＤ－Ｉ型Ｄｕｍｍｙ的有限元模型的基础上，给出了对ＥＵＲＯＳＩＤ－Ｉ型Ｄｕｍｍｙ的计算机数值模拟结果及分析。通过对有关试验结果的验证，可知该模型是合理有效的。

Effect coding与dummy coding赋值方法及其医学研究应用

目的介绍effect coding的变量赋值方法及其在医学研究中的应用,并与dummy coding方法比较。方法将2005年调查中搜集到西部10省40个县的村医20125张处方作为分析资料,省作为分类变量,分别采用dummy coding与effect coding两种编码方式纳入模型,分析处方费用的影响因素,并做比较。结果分类变量的编码方式不同,不会影响回归分析的结果。疾病种类、村医的文化程度、患者年龄、在治疗中是否使用注射剂以及处方所开出的药物个数都是村医处方费用的影响因素。结论 Effect coding在回归的系数的解释方面有其独到的优点,各省份的回归系数之间可以直接进行大小的比较,回归系数的正负表示该省的处方费用较平均水平的高低。

Using dummy data for RFID tag and reader authentication

Radio-Frequency IDentification(RFID)technology is an essential enabler of a multitude of intelligent applications.The robust authentication of RFID system components is critical in providing trustworthy data delivery from/to tags.In this paper,we propose an authentication protocol based on monitoring the transmissions between readers and tags in the system.The proposed authentication scheme is based on injecting decoys within the exchanged communications(between RFID readers and tags)and is used in the authentication process.Furthermore,the proposed authentication scheme is mathematically modeled and validated using extensive simulation.The simulations results show that the proposed scheme provides a 100%confidence level in the authentication of tags and detection of compromised readers.

Study of a 105 GHz short-pulse dummy load for the electron cyclotron resonance heating system with the quasi-optical method

The accurate power measurement is important for an ECRH system in tokamak.The dummy load is designed and developed for the measurement of the millimeter wave power.This work analyzes the dummy load based on the quasi-optical method and the ray tracing method.The reflectivity and thermal deposition of the dummy load have been considered to ensure the safety of the entire system.High-power tests have been carried out at a 105 GHz/500 kW ECRH system.The results of the tests indicate that the designed dummy load is stable and valid.

DUMMY ROV试验平台的设计及应用

DUMMY ROV用于模拟ROV,它是拥有工作级ROV的尺寸、远程操作模式和甲板操作功能的试验平台。在深水工程项目通常会使用尚未参加海上施工项目的ROV设备进行相关操作测试。但由于ROV水下作业环境与水上的差别,用于水下生产设备的ROV系统的陆地测试的效果往往不理想。以ROV使用操作要求及ROV硬件设备为基础搭建的DUMMYROV具备了工作级ROV的陆地操作能力,而且在陆地操控的耐受性上强于工作级ROV。

Influence of platform position on stray grain nucleation in Ni-based single-crystal dummy blade clusters

Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process.In this study,a single-crystal dummy blade cluster with different crystal orientations controlled by the seeding method was prepared,and the influence of the position of the circular platform(relative to the sample and furnace body)on stray grain nucleation was investigated.Results show that the microstructure of the circular platforms could be divided into the center,expansion,and stray grain regions.The inside of the circular platform facing the center of the cluster is more prone to stray grain formation than the outside of the circular platform facing the furnace body.With an increase in the distance between the circular platform and the bottom of the dummy blade cluster,the stray grain region expands,whereas the expansion region narrows.The stray grain is slightly aggravated with increase of the misorientation.Finally,the mechanism underlying the influence of platform position on the formation of stray grains in single-crystal dummy blade clusters is discussed based on the temperature evolution during directional solidification.

The Reliability of the Anaerobic Power Dummy Throw Test in High School Wrestlers:A Pilot Study

AP(anaerobic power)output is an important physical characteristic that is required to succeed in sports such as wrestling.The Wingate test is considered the Gold Standard for assessing AP but is not specific to the sport of wrestling.The purpose of this study was to examine the reliability of a novel field test known as the LWAPT(Lopez wrestling anaerobic power test)for the assessment of AP.The participants were male high school wrestlers(n=10,age:17.0±0.8 yrs,mass:70.9±10.2 kgs).The participants met on one occasion in order to complete the testing protocol.The protocol initiated with the participants completing a 10-15 minute dynamic WU(warm-up)that included three practice dummy throw attempts(dummy mass=31.75 kgs).Following the dynamic WU(≈5 minutes),the participants performed two trials of the LWAPT.In order to perform the LWAPT,wrestlers stood behind the wrestling dummy in a squat position with legs bent at 45-90 degrees.Next the wrestlers wrapped their arms around the waist of the dummy and on the signal“go”the wrestlers quickly exploded up,lifting the dummy by getting triple extension with the ankles,knees and hips as one would in a power clean.After the wrestler was fully extended,he turned in midair in order to drive the dummy onto its stomach on the ground,where the wrestler was on top of the back of the dummy(a common position after an opponent has been thrown).The participant then repositioned the dummy to the original position to execute another throw.The participants completed as many dummy throws as possible during the one minute trials.The LWAPT trials were separated by 15 minutes.The trial scores were 15.6±2.5 and 17.2±1.5 throws respectively.The interclass and intraclass reliability coefficients were r=0.84 and ICC=0.80.The standard error of the measure was SEm=1.0 throws with 90%confidence limits of UL:1.7,LL:0.7.The mean difference between trials was 1.6±1.4 throws(90%confidence limits of UL:2.4,LL:0.8).Bland-Altman plots suggested agreement between trials with no evidence of heteroscedasticity.The LWAPT exhibits moderate to high reliability as an assessment of AP.The inclusion of additional dummy throw trials to the assessment protocol may enhance the degree of reliability of the dummy throw test as a measure of AP.

An improved window opening behavior model involving the division of the dummy variable’s interval level:Case study of an office building in Xi’an during summer

Window opening behavior significantly impacts indoor air quality,thermal comfort,and energy consumption.A field measurement was carried out in three typical rooms(a standard office,a meeting room and a smoking office)within an office building.The window state and the physical environment were continuously recorded during the measured periods.Three typical window opening behaviors were found in the measured samples,namely,active,moderate,and passive.The common logistic regression coefficient indicated that solar radiation exhibited the greatest effect on window opening behavior in the smoking office and standard office.Typically,window opening behavior in the meeting room was the most strongly correlated with time of the day,mainly because of the meeting schedule for occupants in the meeting room.This study discussed the dividing principles involved in setting the dummy variable interval level(discretizing continuous variables and dividing them into different intervals),and proposed a method to determine the optimal interval level of each variable.The improved model led to the increase in the prediction accuracy rate of the window being opened by 2.0%and 3.3%according to the comparison with the original model based on dummy variables and the common model based on continuous variables,respectively.This study can provide a reference value for simulating energy consumption in office buildings in the future.

DUMMY ROV在水下设施陆地安装试验中的应用

DUMMYROV是模拟ROV,它是拥有工作级ROV的尺寸、ROV的远程操作模式、ROV的甲板操作功能的试验平台。随着国内深水工程项目的不断增加,对于水下设施安装试验及功能测试要求不断增加。而以ROV操作需求及ROV硬件设备为基础搭建的DUMMYROV具有易操控、耐受性强、设备折旧率低等特点,DUMMY ROV应用于水下设施陆地试验项目中具有较大优势。DUMMY ROV可以通过结构设计、液压设计及模拟试验操作完成陆地安装试验中要求的安装空间模拟、功能驱动测试、机械手操作测试等内容。

Dummy ROV结构功能与具体应用

作为海洋工程应用的专业工具之一,ROV应用范围非常广泛。其辅助工具Dummy ROV也发挥着非常重要的作用。本文从Dummy ROV的结构配置、工作特点、作用功能和应用注意事项四个方面对Dummy ROV做了简单介绍。

医用回旋加速器工作状态下束流稳定性分析

目的分析医用回旋加速器两种工作状态下加速束流的基本特征;监测加速器在较高负荷运行条件下的束流稳定性。方法利用高纯氢气作为离子源气体,分别自加速末端提取单、双束流,测试两种条件下离子源电流、引出束流及加速环境的真空度随时间的变化趋势。结果真空腔的真空度、离子源电流及准直器电流在双束流测试时变化幅度相对较大,两种测试条件下,真空度及离子源呈缓慢递增趋势,准直器电流呈缓慢递减趋势,60min后趋于稳定。结论正常工作状态下,单束流比双束流轰靶的束流稳定性强,且两种条件下束流最终处于较稳定的工作状态。应优先选择单束流工作模式。

开放式全自动生化仪加样性能确认研究

介绍一种评价新型全自动生化仪加样性能的方法。用色素法对样品针的加样性能,称重法对试剂针的加样性能以及Dummy量进行确认,并对不同情况下的Dummy量进行比较研究,为应用全自动生化分析仪提供了有价值的参考。

一种低电荷注入误差的开关电流电路

对限制开关电流电路(SI)精度的主要因素以及开关电荷注入误差等问题进行了详细的分析。在此基础上,提出了两种消除开关电荷注入误差的可能结构:在常电压开关(CVS)基础上的dummy开关结构和基于CVS的全差分结构。其主要思想是将与信号大小有关的电荷注入误差变为与信号无关的电荷注入误差。并以此为基础,采用dummy结构或全差分结构,进一步消除该误差。用0.35μm模型参数进行了HSPICE仿真,结果证明,该结构能很好地降低电荷注入误差,提高SI电路的精度。

形式动词的次分类

1.1 现代汉语有一类动词,常见的是“加以、给以、予以、给予、进行、作”等,这类动词能够带一个动词组成述宾结构,表示对人或事物处置和对待,其本身却不表示具体的动作行为意义,只充当形式上的述语,而让后边动词宾语来负载这个述宾结构的语义信息。我们把这类动词叫做形式动词(dummy verb,以下标记为DV)。 1.2 DV可以分为两个次类: DVa 加以 给以 予以 给予 DVb 进行 作 分类的依据如下。 2.1 在语义上,DVa表示施加义和授予义,具有短时完成、非持续、无过程的时间和要求受事的空间特征。例如: (1)对重要的问题要加以论证。(《邓小平文选》) (2)共产党员要对这种不正之风予以抵制。 (3)对实行计划生育的,要给予优待。(《周恩来选集》下卷) 因此DVa的语义特征可以记作[+完成]、[—持续],[—过程]、[+要求受事]。 DVb表示从事义和举行义,具有非短时完成、可持续、有过程的时间特征。在空间特征上,DVb有时要求受事,有时不要求受事。例如: