OPTIMAL POLICY WITH A TOTAL ORDER QUANTITY COMMITMENT CONTRACT IN THE PRESENCE OF A SPOT MARKET

In this paper, the optimal policy is considered when the buyer faces two supply sources： one is the contract supplier from which the buyer orders over a specific contract period （say, a year） at a pre-agreed price, and the other is the spot market. However, when ordering from the contract supplier, the buyer must fulfill a pre-determined total order quantity, or the so-called definite total order quantity commitment, over the whole contract period. In other words, the commitment secures the buyer a fixed price but obliges him/her a total order quantity over the contract period. Although the spot market gives the buyer more flexibility in terms of order quantities, its prices are volatile. Such a combination of contract and spot procurements is often observed in practice. Within the contract period, there are multiple sub-periods, during each of which the buyer reviews the inventory, issues an individual order, and uses the on-hand inventory to meet the random demand. Thus, in each （ordering） period, the buyer will weigh between the current known spot price （by procuring from the spot market） and a lower future price （by waiting while consuming the remaining commitment）. An optimal dual ordering policy is characterized for each period, depending on the on-hand inventory level, the spot price, and the remaining commitment quantity. The optimal policy in each period is also shown to be independent of the contract price. Through a numerical study, the inventory cost is demonstrated to be （1） insensitive to the contract price when the total commitment quantity is lower than the total expected demand over the contract period and （2） non-increasing in the variability of spot prices.

Non-blocking message total ordering protocol

Message total ordering is a critical part in active replication in order to maintain consistency among members in a fault tolerant group. The paper proposes a non-blocking message total ordering protocol （NBTOP） for distributed systems. Non-blocking property refers to that the members in a fault tolerant group keep on running independently without waiting for installing the same group view when a fault tolerant group evolves even when decision messages collide. NBTOP takes advantage of token ring as its logical control way. Members adopt re-requesting mechanism （RR） to obtain their lost decisions. Forward acknowledgement mechanism （FA） is put forth to solve decision collisions. The paper further proves that NBTOP satisfies the properties of total order, agreement, and termination. NBTOP is implemented, and its performance test is done. Comparing with the performance of Totem, the results show that NBTOP has a better total ordering delay. It manifests that non-blocking property helps to improve protocol efficiency.

全偏联系数中不确定示性系数i取值的探究

一阶全偏联系数是揭示“同异反”三元联系数所描述的系统整体状态在内部动态演化的一个伴随函数.用量子力学理念揭示系统从“正常”到“失常”两个极端状态改进算法,获得新的表达式,用实例展示其成效.

不同程度近视患者行SMILE术后的有效光学区及角膜高阶像差比较

目的:比较低、中、高度近视患者行飞秒激光小切口基质透镜取出术(SMILE)后的有效光学区和角膜高阶像差。方法:收集2019-02/2021-02在我院行SMILE手术的患者134例,均取右眼入组,按等效球镜度(SE)分为低度近视组SE>-3.00 D,中度近视组-6.00 D<SE≤-3.00 D,高度近视组SE≤-6.00 D三组,分别于术前和术后1 mo行Pentacam检查,分析各组内手术前后角膜总高阶像差(tHOA)、球差、彗差有无差异,及术后三组间角膜总高阶像差、球差、彗差及有效光学区大小(EOZ)有无差异。结果:SMILE术后1 mo,三组术后有效光学区均小于预设光学区,随着屈光度数增加,有效光学区越小(P<0.05);术后1 mo角膜总高阶像差、球差、彗差均高于术前,除低近视度组球差术前与术后1 mo无差异(P>0.05),其余组别均有差异(P<0.05);角膜总高阶像差、球差和彗差随着屈光度数增加而增加,三组角膜总高阶像差和球差有差异(均P<0.05),高度近视组与中度近视组、低度近视组彗差结果均有差异(P<0.05),中度近视组与低度近视组彗差结果无差异(P>0.05)。结论:随着手术矫正的屈光度数增加,术后有效光学区减少越多,角膜高阶像差增加越明显;SMILE术后1 mo角膜高阶像差较术前增加。

基于分数阶全变分和扩散模型的图像去模糊方法

图像去模糊是数字图像处理领域的重要研究方向之一.在许多实际应用中,由于成像设备和物体之间发生相对运动,产生的模糊会降低图像质量和视觉效果.本文提出了一种结合分数阶全变分(FTV)损失函数和去噪扩散概率模型(DDPM)的图像去模糊方法 .首先通过基于概率建模的DDPM实现对图像结构信息的增强,然后利用FTV损失函数作为正则项,进一步恢复图像细节.与传统的图像去模糊方法相比,本文方法能够在保持图像整体清晰度的同时,还原更多的图像细节信息.实验结果验证了该方法在恢复受运动模糊影响的图像上具有显著优越性,为图像去模糊领域的进一步发展提供了新方向.

电液伺服系统的扩展自耦PD控制

针对具有高度非线性和参数不确定性的3阶电液伺服系统,基于自耦PID控制理论提出了一种扩展自耦PD控制方法。通过将电液伺服系统内部动态与外部不确定因素定义为总扰动,使3阶非线性系统等价映射为3阶线性扰动系统,形成一个在总扰动激励下的受控误差系统,并以自适应速度因子为基础设计了扩展自耦PD控制器,理论分析了扩展自耦PD闭环控制系统具有良好的鲁棒稳定性和抗扰动鲁棒性。仿真实验表明:该控制方法不仅动态响应速度快,且稳态控制精度高,因此在电液伺服系统领域具有良好的实际应用前景。

柴达木盆地柴西坳陷古近系-新近系石油地质特征与油气环带状分布模式

柴达木盆地柴西坳陷古近系-新近系石油资源丰富,常规石油与页岩油分别占全盆地常规石油资源的82.4%和非常规页岩油资源的100%。通过研究沉积储层与石油地质特征,剖析柴西坳陷古近系-新近系沉积相和油气成藏特征,提出了油气环带状分布模式。研究认为:①柴西坳陷古近系-新近系沉积相带呈“环带状”分布。外环带为三角洲与滩坝相,以碎屑岩沉积为主,碳酸盐岩沉积较少,发育砾岩、含砾粗砂岩和中-粗砂岩储层。中环带以滨浅湖灰云坪、灰泥坪相沉积为主,发育细砂岩、粉砂岩、灰云岩及藻灰岩,藻灰岩是中环带最具特色且孔隙度最高的岩相类型。内环带以半深湖-深湖相细粒混积岩沉积为主,发育深灰、暗灰色细粒沉积岩,是古近系-新近系最主要的烃源岩发育区。②不同沉积相环带内油藏类型不同。外环带距离生烃灶较远,油气经断层输导在砾岩、粗砂岩等碎屑岩中聚集,形成构造油气藏。中环带紧邻主力生烃灶,油气经断层输导在藻灰岩等碳酸盐岩储层中储集,形成构造-岩性油气藏。内环带油气短距离运移或原位滞留在细粒混积岩中源-储一体,形成页岩油。柴西坳陷从源外到源内,构造-岩性油气藏与页岩油纵向上相互叠置,平面上构造油气藏、构造-岩性油气藏与页岩油呈环带状分布。

江苏省一、二等水准测量成果质量问题浅析

一、二等水准测量在区域现代测绘高程基准维持与更新、区域地面沉降监测、城市轨道交通工程高程控制网等测量工程中广泛应用。承担一、二等水准测量项目的都为具有大地测量或工程测量甲级测绘资质且综合实力较强的生产单位。根据《国家一、二等水准测量规范》(GB/T 12897-2006)、《测绘成果质量检查与验收》(GB/T 24356-2009)等生产和检查验收规范,对近几年检验的江苏省范围内的一、二等水准测量项目成果质量问题进行了汇总。这些项目成果质量具有一些典型的问题,对产生问题的原因进行了简要分析,对于测绘单位规范生产、提高成果质量有着较强的借鉴意义。

Regression model for stabilization energies associated with anion ordering in perovskite-type oxynitrides

Certain perovskite-type oxynitrides have bandgaps suitable for renewable hydrogen production via photocatalytic and photoelectrochemical water splitting under visible light.Understanding the ordering of oxide and nitride anions in these materials is important because this ordering affects their semiconductor properties.However, the numerous possible orderings complicate systematic analyses based on density functional theory(DFT) calculations using defined elemental arrangements.This work shows that anion ordering in large-scale supercells within perovskite-type oxynitrides can be rapidly predicted based on machine learning, using BaNbO2N(capable of oxidizing water under irradiation up to 740 nm) as an example.Machine learning allows the calculation of the total energy of BaNbO2N directly from randomly selected initial atomic placements without costly structural optimization, thus reducing the computational cost by more than 99.99%.Combined with the Metropolis Monte Carlo method, machine learning permits exploration of the stable anion orderings of large supercells without costly DFT calculations.This work therefore demonstrates a means of predicting the properties of functional materials having complex compositions based on the most realistic elemental arrangements in conjunction with reasonable computational loads.

SOME COMPARISONS BETWEEN GENERALIZED ORDER STATISTICS

Some stochastic comparisons of generalized order statistics under the right spread order, the location independent riskier order and the total time transform order are investigated in this paper. The underlying distributions and parameters on which generalized order statistics are based are also surveyed to obtain the conditions for increasing the expectations of spacings between the first two generalized order statistics and between the last two generalized order statistics.

Fourth-Order Adjoint Sensitivity Analysis of an OECD/NEA Reactor Physics Benchmark: II. Mathematical Expressions and CPU-Time Comparisons for Computing 4^th-Order Sensitivities

This work extends to fourth-order previously published work on developing the adjoint sensitivity and uncertainty analysis of the numerical model of a polyethylene-reflected plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. Previous works showed that the third-order sensitivities of the PERP leakage response with respect to these total microscopic cross sections are far larger than the corresponding 1st-order and 2nd-order ones, thereby having the largest impact on the uncertainties induced in the PERP benchmark’s response. This finding has motivated the development of the original 4th-order formulas presented in this work, which are valid not only for the PERP benchmark but can also be used for computing the 4th-order sensitivities of response of any nuclear system involving fissionable material and internal or external neutron sources. Subsequent works will use the adjoint-based mathematical expressions obtained in this work to compute exactly and efficiently the numerical values of the largest fourth-order sensitivities of the PERP benchmark’s response to the total microscopic cross sections, and use them for a pioneering fourth-order uncertainty analysis of the PERP benchmark’s response.

Third Order Adjoint Sensitivity and Uncertainty Analysis of an OECD/NEA Reactor Physics Benchmark: III. Response Moments

The (180)3 third-order mixed sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) experimental benchmark with respect to the benchmark’s 180 microscopic total cross sections have been computed in accompanying works [1] [2]. This work quantifies the contributions of these (180)3 third-order mixed sensitivities to the PERP benchmark’s leakage response distribution moments (expected value, variance and skewness) and compares these contributions to those stemming from the corresponding first- and second-order sensitivities of the PERP benchmark’s leakage response with respect to the total cross sections. The numerical results obtained in this work reveal that the importance of the 3rd-order sensitivities can surpass the importance of the 1st- and 2nd-order sensitivities when the parameters’ uncertainties increase. In particular, for a uniform standard deviation of 10% of the microscopic total cross sections, the 3rd-order sensitivities contribute 80% to the response variance, whereas the contribution stemming from the 1st- and 2nd-order sensitivities amount only to 2% and 18%, respectively. Consequently, neglecting the 3rd-order sensitivities could cause a very large non-conservative error by under-reporting the response variance by a factor of 506%. The results obtained in this work also indicate that the effects of the 3rd-order sensitivities are to reduce the response’s skewness in parameter space, rendering the distribution of the leakage response more symmetric about its expected value. The results obtained in this work are the first such results ever published in reactor physics. Since correlations among the group-averaged microscopic total cross sections are not available, only the effects of typical standard deviations for these cross sections could be considered. Due to this lack of correlations among the cross sections, the effects of the mixed 3rd-order sensitivities could not be quantified exactly at this time. These effects could be quantified only when correlations among the group-averaged microscopic total cross sections would be obtained experimentally by the nuclear physics community.

Third Order Adjoint Sensitivity and Uncertainty Analysis of an OECD/NEA Reactor Physics Benchmark: II. Computed Sensitivities

This work presents the results of the exact computation of (180)3 = 5,832,000 third-order mixed sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) experimental benchmark with respect to the benchmark’s 180 microscopic total cross sections. This computation was made possible by applying the Third-Order Adjoint Sensitivity Analysis Methodology developed by Cacuci. The numerical results obtained in this work revealed that many of the 3rd-order sensitivities are significantly larger than their corresponding 1st- and 2nd-order ones, which is contrary to the widely held belief that higher-order sensitivities are all much smaller and hence less important than the first-order ones, for reactor physics systems. In particular, the largest 3rd-order relative sensitivity is the mixed sensitivity of the PERP leakage response with respect to the lowest energy-group (30) total cross sections of 1H (“isotope 6”) and 239Pu (“isotope 1”). These two isotopes are shown in this work to be the two most important parameters affecting the PERP benchmark’s leakage response. By comparison, the largest 1st-order sensitivity is that of the PERP leakage response with respect to the lowest energy-group total cross section of isotope 1H, having the value , while the largest 2nd-order sensitivity is . The 3rd-order sensitivity analysis presented in this work is the first ever such analysis in the field of reactor physics. The consequences of the results presented in this work on the uncertainty analysis of the PERP benchmark’s leakage response will be presented in a subsequent work.

二阶广义总变分约束的太阳图像多帧盲解卷积

盲解卷积是常用的自适应光学图像事后重建方法之一。为提高盲解卷积对太阳(自适应光学)图像的重建效果,本文提出了基于二阶广义总变分的空变多帧盲解卷积算法。该算法首先利用交替最小化和半二次分裂方法求解本文提出的二阶广义总变分约束的空不变多帧盲解卷积模型;然后针对非等晕大视场太阳图像特性,利用重叠分块与加权拼接实现空变盲解卷积扩展。在一米新真空太阳望远镜(NVST)观测的真实太阳图像上进行的重建实验与分析表明,本文算法在主观视觉效果和客观指标上均具有较好的图像重建效果。

全膝关节置换术的围术期异体输血分析及备血方案更新

目的了解全膝关节置换术患者围术期异体红细胞输注率及其危险因素,并分析交叉配血-输血比(C∶T比)。方法本研究为回顾性队列研究。收集2014年1月~2019年10月在本医院行全膝关节置换术和翻修术的患者围术期资料。计算围术期异体红细胞输注率,采用二分类Logistic回归分析其危险因素。计算围术期C∶T比,根据手术类型和年龄等进行亚组分析。结果2903例患者纳入研究,其围术期异体红细胞输注率为10.9%(95%CI 9.8%~12.0%),C∶T比为5.6∶1,危险因素为年龄(OR=1.025,95%CI 1.009~1.042,P<0.01)、术前血红蛋白(OR=0.966,95%CI 0.954~0.978,P<0.001)、术前贫血(OR=3.543,95%CI 2.052~6.119,P<0.001)、血液系统疾病(OR=6.462,95%CI 2.479~16.841,P<0.001)、双侧手术(OR=7.681,95%CI 5.759~10.245,P<0.01)和翻修手术(OR=9.584,95%CI 4.360~21.065,P<0.001)。结论围术期年龄增加、术前低血红蛋白、术前贫血、合并血液系统疾病、双侧手术和翻修手术是全膝关节置换术围术期输血的独立危险因素。术前无贫血、无血液系统疾病、年龄<75岁的单侧手术患者可以仅完成分型筛选,术前贫血、有血液系统疾病、双侧和翻修手术,推荐至少交叉配血1~4 U。

Third-Order Adjoint Sensitivity Analysis of an OECD/NEA Reactor Physics Benchmark: I. Mathematical Framework

This work extends to third-order previously published work on developing the adjoint sensitivity and uncertainty analysis of the numerical model of a polyethylene-reflected plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. The PERP benchmark comprises 21,976 imprecisely known (uncertain) model parameters. Previous works have used the adjoint sensitivity analysis methodology to compute exactly and efficiently all of the 21,976 first-order and (21,976)2 second-order sensitivities of the PERP benchmark’s leakage response to all of the benchmark’s uncertain parameters, showing that the largest and most consequential 1st- and 2nd-order response sensitivities are with respect to the total microscopic cross sections. These results have motivated extending the previous adjoint-based derivations to third-order, leading to the derivation, in this work, of the exact mathematical expressions of the (180)3 third-order sensitivities of the PERP leakage response with respect to these total microscopic cross sections. The formulas derived in this work are valid not only for the PERP benchmark but can also be used for computing the 3rd-order sensitivities of the leakage response of any nuclear system involving fissionable material and internal or external neutron sources. Subsequent works will use the adjoint-based mathematical expressions obtained in this work to compute exactly and efficiently the numerical values of these (180)3 third-order sensitivities (which turned out to be very large and consequential) and use them for a third-order uncertainty analysis of the PERP benchmark’s leakage response.

某院全肠外营养液住院医嘱分析

目的为住院患者全肠外营养液(TPN)中氨基酸、维生素等营养素的合理应用提供参考。方法参照专家共识、相关指南及药品说明书制订TPN用药合理性评价标准,选取南京医科大学附属淮安第一医院2019年至2021年的246例住院患者的267份TPN用药医嘱,对其氨基酸、维生素、葡萄糖、脂肪乳等营养素的应用进行合理性评价。结果246例TPN患者中,≥60岁152例(61.79%);肝胆胰外科收治145例(58.94%);平均疗程(7.19±5.18)d,疗程5~10 d 119例(48.37%)。267份TPN医嘱中,肝功能正常使用复方氨基酸(20AA)107份(40.07%),肝功能异常使用复方氨基酸(18AA-Ⅱ)及复方氨基酸(18AA-Ⅱ-SF)11份(4.12%);使用维生素合理22份(8.24%),使用脂溶性维生素未使用水溶性维生素233份(87.27%);使用甘油磷酸钠21份(7.87%)。结论TPN中各种复方氨基酸注射液和维生素的应用存在较多问题,较突出的是磷制剂和药理营养素应用比例较低。临床药师应加强TPN医嘱前置审核,促进TPN中各种复方氨基酸注射液和维生素制剂的合理、规范使用。

品管圈提升全肠外营养液医嘱调配准确率效果评价

目的提升静脉用药调配中心(PIVAS)全肠外营养(TPN)液医嘱调配准确率。方法PIVAS通过成立品管圈(QCC)小组,按拟订活动计划、确定活动目标、明确主要原因、制订和实施对策4个标准化步骤进行QCC活动。统计医院2020年11月至2021年2月TPN液医嘱调配差错率,并制订改进措施。比较实施QCC活动前后TPN液医嘱调配差错率。结果QCC活动后(2021年6月至9月),TPN液医嘱调配差错率为2.01%,显著低于活动前的3.65%(P<0.05);QCC组员的品管手法、和谐度、解决问题的能力、积极性、自信心、沟通协调、责任心的平均得分,分别由活动前的2.14,3.14,3.14,3.14,3.14,3.14,3.57分升至活动后的4.00,4.86,4.00,4.57,4.00,4.14,4.14分。结论QCC活动可明显提升TPN液调配准确率,并形成标准化的有效措施,保障TPN液调配的安全性和有效性。

信号失真度测量装置设计

针对传统总谐波失真测量方法的局限性,设计了以快速傅里叶变换算法为核心的总谐波失真测量装置。该装置由电压偏置电路、自动增益控制电路、四阶滤波电路等组成,通过了单次时间、精度、数据对比等测试验证。结果表明:输入信号基波幅度在30~600 mV范围内,装置的总谐波失真测量值与理论计算值的相对误差小于5%;单次测量完成时间小于5 s。该装置具有高精度、可控增益、测量与运算速度快等优点,可用于分析和测量总谐波失真度,为信号的保持与还原提供了数据支撑。

分数阶q-Laplace 全变差图像修补模型的增广拉格朗日算法实现

分数阶TV正则项已被广泛应用于图像处理领域,本文针对一类q-Laplace全变差图像修补模型,采用增广拉格朗日方法进行求解并设计了快速算法,数值实验表明本文所提出的算法对有文字遮挡和人工涂画痕迹的图像具有一定的修补作用。