U-Type Designs via New Generalized Partially Balanced Incomplete Block Designs with <i>m</i>= 4, 5 and 7 Associated Classes

The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design).

On the Convergence of Observed Partial Likelihood under Incomplete Data with Two Class Possibilities

In this paper, we discuss the theoretical validity of the observed partial likelihood (OPL) constructed in a Coxtype model under incomplete data with two class possibilities, such as missing binary covariates, a cure-mixture model or doubly censored data. A main result is establishing the asymptotic convergence of the OPL. To reach this result, as it is difficult to apply some standard tools in the survival analysis, we develop tools for weak convergence based on partial-sum processes. The result of the asymptotic convergence shown here indicates that a suitable order of the number of Monte Carlo trials is less than the square of the sample size. In addition, using numerical examples, we investigate how the asymptotic properties discussed here behave in a finite sample.

Reflection of Oblique Incident Waves by Breakwaters with Partially-Perforated Wall

The reflection of oblique incident waves from breakwaters with a partially-perforated front wall is investigated. The fluid domain is divided into two sub-domains and the eigenfunction expansion method is applied to expand velocity potentials in each domain. In the eigen-expansion of the velocity potential, evanescent waves are included. Numerical results of the present model are compared with experimental data. The effect of porosity, the relative chamber width, the relative water depth in the wave absorbing chamber and the water depth in front of the structure are discussed.

The force of oblique incident wave on the breakwater with a partially perforated wall

Wave forces induced by the interaction between the oblique incident wave and the breakwater with a partially perforated front wall is investigated. The fluid domain is divided into two sub-domains and the eigen-function expansion method is applied to expanding velocity potentials in each domain. In the eigen-expansion of the velocity potential, evanescent waves are included. Numerical results of the present model are compared with other theories and a good agreement can be found between them. Experimental data have been compared with the present theoretical results. The effect of the traverse wall on wave forces has been discussed in detail. On the basis of the linear wave theory, it is shown that in the range Of engineering practice, the incident angle of wave has small influence on wave forces on the unit length of perforated caisson.

The reflection of regular and irregular waves by a partially perforated caisson breakwater on a step bed

This study examines the reflection of regular and irregular waves from a partially perforated caisson breakwater located on a step bed. The step bed is treated as an idealized rubble mound foundation. Based on the linear potential theory, an analytical solution is developed to calculate the reflection coefficient of the structure subjected to regular waves. The matched eigenfunction expansion method is used for the solution. The regular wave method is also extended to irregular waves using a linear transfer function. The calculated results obtained for limiting cases are exactly the same as corresponding results given by the previous researchers. The present predictions also agree well with experimental data in the published literatures. Numerical experiments are conducted to examine the variations of the reflection coefficient versus its main effect factors, and some interesting results are presented.

Reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core

The reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core is examined. The present mathematical model is developed by means of the matched eigenfunction method. Numerical results of the present model are compared with the experimental data of different researchers. Numerical examples are given to examine the effect of rock fill on the reflection coefficient. The differences between regular and irregular waves are also investigated by means of theoretical and experimental results. It is found that the minimum reflection coefficient of irregular waves is larger than that of corresponding regular waves, but the contrary is the case for the maximum reflection coefficient.

Iterative analytical solution for wave reflection by a multichamber partially perforated caisson breakwater

This study examines wave reflection by a multi-chamber partially perforated caisson breakwater based on potential theory.A quadratic pressure drop boundary condition at perforated walls is adopted,which can well consider the effect of wave height on the wave dissipation by perforated walls.The matched eigenfunction expansions with iterative calculations are applied to develop an analytical solution for the present problem.The convergences of both the iterative calculations and the series solution itself are confirmed to be satisfactory.The calculation results of the present analytical solution are in excellent agreement with the numerical results of a multi-domain boundary element solution.Also,the predictions by the present solution are in reasonable agreement with experimental data in literature.Major factors that affect the reflection coefficient of the perforated caisson breakwater are examined by calculation examples.The analysis results show that the multi-chamber perforated caisson breakwater has a better wave energy dissipation function(lower reflection coefficient)than the single-chamber type over a broad range of wave frequency and may perform better if the perforated walls have larger porosities.When the porosities of the perforated walls decrease along the incident wave direction,the perforated caisson breakwater can achieve a lower reflection coefficient.The present analytical solution is simple and reliable,and it can be used as an efficient tool for analyzing the hydrodynamic performance of perforated breakwaters in preliminary engineering design.

Experimental and Theoretical Investigation of Wave Forces on APartially-Perforated Caisson Breakwater with A Rock-Filled Core

The total horizontal and vertical forces acting on a partially-perforated caisson breakwater and their phase difference are investigated in this study. The perforated breakwater sits on the rubble tilled foundation, and has a rock-filled core. An analytical solution is developed based on the eigenfunction expansion and matching method to solve the wave field around the breakwater. The finite element method is used for simulating the wave-induced tlow in the rabble-filled foundation. Experiments are also conducted to study the wave forces on the perforated caissons. Numerical predictions of the present model are compared with experimental resuhs. The phase differences between the total horizontal and vertical forces are particularly analyzed by means of experimental and numerical results. The major factors that affect the wave forces are examined.

Numerical Method for Wave Forces Acting on Partially Perforated Caisson

The perforated caisson is widely applied to practical engineering because of its great advantages in effectively wave energy consumption and cost reduction. The attentions of many scientists were paid to the fluid–structure interaction between wave and perforated caisson studies, but until now, most concerns have been put on theoretical analysis and experimental model set up. In this paper, interaction between the wave and the partial perforated caisson in a 2D numerical wave flume is investigated by means of the renewed SPH algorithm, and the mathematical equations are in the form of SPH numerical approximation based on Navier–Stokes equations. The validity of the SPH mathematical method is examined and the simulated results are compared with the results of theoretical models, meanwhile the complex hydrodynamic characteristics when the water particles flow in or out of a wave absorbing chamber are analyzed and the wave pressure distribution of the perforated caisson is also addressed here. The relationship between the ratio of total horizontal force acting on caisson under regular waves and its influence factors is examined. The data show that the numerical calculation of the ratio of total horizontal force meets the empirical regression equation very well. The simulations of SPH about the wave nonlinearity and breaking are briefly depicted in the paper, suggesting that the advantages and great potentiality of the SPH method is significant compared with traditional methods.

Surgical Outcomes Following Partial Breast Reconstruction with Chest Wall Perforator Flaps

Introduction: In the last two decades, chest wall perforator flaps (CWPF) have become a versatile tissue replacement technique for partial breast reconstruction following breast-conserving surgery (BCS) in well-selected cases. We present the surgical outcome of 81 patients with chest wall perforator flaps used for breast-conserving surgery. Methods: We recorded the outcomes of three oncoplastic breast surgeons who performed partial breast reconstruction with chest wall perforator flaps from 1st January 2018 to 30th June 2022 at Sherwood Forest Hospitals NHS Foundation Trust. Data were collected on patient demographics, including age, BMI, smoking status, bra size, previous treatments, type of CWPF procedure, tumor size (measured clinically, via imaging and histologically), biopsy results, specimen weight, margins involvement, re-operation rate, surgical site infection (SSI), flap loss, flap shrinkage, hematoma, and seroma rates. Results: A total of 81 patients were included in this study, with an average age of 55.7 years and a body mass index (BMI) of 26.7 kg/m2. The bra size varied between A to FF with A (7.4%), B (28.3%), C (38.2%), D (13.6%), DD (11.1%), and FF (1.2%). 14.8% of the patients had neoadjuvant chemotherapy (NACT). For 45 patients, LICAP (lateral intercostal artery perforator), 16 AICAP (anterior intercostal artery perforator), 13 MICAP (medial intercostal artery perforator), and for seven patients, LTAP (lateral thoracic artery perforator) flaps were used. The average tumor was measured at 15.75 mm clinically, 19.1 mm via imaging, and 19.6 mm histologically. Biopsy showed that 16% of the tumors were ductal carcinoma in situ (DCIS), and 84% were invasive. 16% of patients had involved margins, and re-excision was required in 10 patients, and completion mastectomy was performed in 2 patients. A thirty-day SSI rate was 6.2%, with flap-related complications, including flap loss and shrinkage, at 3.7% and 4.9%, respectively. In addition, 3.7% had a hematoma, and 17.3% had other complications. Conclusion: Partial breast reconstruction with perforator flaps is an excellent volume replacement technique in breast-conserving surgery with acceptable complications in well-selected cases.

Three-dimensional numerical simulation of wave interaction with perforated quasi-ellipse caisson

The finite difference method and the volume of fluid （VOF） method were used to develop a three-dimensional numerical model to study wave interaction with a perforated caisson. The partial cell method was adopted to solve this type of problem for the first time. The validity of the present model, with and without the presence of caisson structures, was examined by comparing the model results with experimental data. Then, the numerical model was used to investigate the effects of various wave and structure parameters on the wave force and wave runup of the perforated quasi-ellipse caisson. Compared with the solid quasi-ellipse caisson, the wave force on the perforated quasi-ellipse caisson is significantly reduced with increasing porosity of the perforated quasi-ellipse caisson. Furthermore, the perforated quasi-ellipse caisson can also reduce the wave runup, and it tends to decrease with the increase of the porosity of the perforated quasi-ellipse caisson and the relative wave height.

Surgical Experience of a Partial Atrioventricular Septal Defect in an Elderly Patient: A Case Report

The following paper describes patch closure (bovine pericardial sheet) of an ostium primum atrial septal defect and mitral valve repair (sutured mitral valve cleft + autologous pericardial annuloplasty + Alfieri’s method) in a 50-year-old man. He had been perfectly well until he was brought to the emergency room because of acute heart failure. Chest radiography revealed right-side heart enlargement. Electrocardiography indicated atrial flutter. Echocardiography revealed a large ostium primum atrial septal defect and moderate mitral regurgitation. The pulmonary-to-systemic blood flow ratio was 3.24. First, cardiologists performed catheter ablation of the cavotricuspid isthmus for atrial flutter. We performed patch closure of an ostium primum atrial septal defect and mitral valve repair after the patient’s heart failure was under control. The patient was discharged 13 days postoperatively in a satisfactory condition without any critical complications.

基于背景间运算的部分已知概念构造

概念是利用形式概念分析进行知识获取的基础。在不完备形式背景中,为了表达“一定具有”以及“可能具有”的关系,概念的外延或内涵通常以区间集的形式表达,称这样的概念为部分已知概念。由部分已知概念的定义可知,其本质与不完备背景的最小和最大完备化有关,因而考虑对最小和最大完备化背景进行运算来寻找部分已知概念。通过将不完备形式背景的最小完备化与最大完备化分别进行并置和叠置构造两个新背景,其概念格分别同构于SE-ISI概念格和ISE-SI概念格,从而提出了构建SE-ISI概念格和ISE-SI概念格的新方法。对于ISE-ISI概念,使用不完备形式背景的最小与最大完备化的直和运算构造了新的形式背景,基于此背景提出了寻找ISE-ISI概念的方法。

不完备区间值信息系统中的粗集理论

针对不完备区间值信息系统,提出了一种用于分类的偏序关系,并给出了计算这种偏序关系约简的实际操作方法。在不完备区间值决策系统中,根据基于偏序关系的粗糙集模型,引入了上、下近似约简的概念。上、下近似约简是保持所有决策类的下、上近似都不发生变化的最小属性子集,借此获取简化的决策规则。

局部开孔沉箱结构在斜向波作用下的受力分析

本文研究了局部开孔沉箱结构与斜向入射波作用时的受力问题。整个流域被分成两个子域,在每个子区域内,应用分离变量法和特征函数展开法以求得相应的速度势,在速度势的特征展开中考虑了非传播模态波。数值计算结果与现有理论进行了对比,结果完全一致;理论计算与试验数据相比符合较好;讨论了横向隔板对沉箱整体受力的影响。最后根据理论计算结果给出了不同入射角度力比和不同单宽力比的简化计算方法,以便工程实际的应用。

考虑不完全射孔的储层热效率评价方法

稠油油藏热利用率的计算普遍为完全射孔的驱替理论模型,没有考虑不完全射孔因素的影响。运用热力学的基本原理和热平衡基础理论,在考虑不完全射孔因素和重力分异影响的基础上,推导了考虑不完全射孔因素的蒸汽驱储层热效率评价方法。研究表明:蒸汽驱初期,射孔影响较大,汽液重力分异作用影响较小,注入蒸汽沿储层射孔段的驱替效果明显,储层热散失率较少;蒸汽驱开采后期,随着蒸汽超覆作用的增强,射孔的影响相对减弱,蒸汽沿储层上部的驱替效果明显,储层热散失较大;部分射孔可有效缓解重力分异的不利影响,提高蒸汽波及效率。

剪切作用对不同聚合物溶液流度控制能力影响研究

为考察剪切作用对不同结构的聚合物溶液性能的影响,分别研究了高相对分子质量部分水解聚丙烯酰胺HPAM溶液和疏水缔合聚丙烯酰胺HAP0210溶液经过模拟炮眼剪切后的流度控制能力。结果表明,溶液中不同分子结构的聚合物经过模拟炮眼剪切作用后其流度控制能力存在显著差异。在炮眼剪切作用下,溶液中HPAM大部分分子链断裂,相对分子质量下降50%左右,分子链间缠结和堆积程度大幅度下降;而具有分子间缔合作用的HAP0210在溶液中的网络结构也受到破坏,相对分子质量下降30%左右,但仍能依靠疏水缔合作用在聚合物溶液中形成相互作用能力较弱的网络结构,使溶液表现出一定的抗剪切能力和较强的建立阻力系数和残余阻力系数的能力。

部分射开井流线数值试井解释模型及压力响应

建立了部分射开井的流线数值试井解释模型,模型包括生产阶段的渗流数学模型和测试阶段的流线数学模型,采用流线方法和有限差分方法分别对生产和测试阶段的数学模型进行数值求解,得到了部分射开井的压力响应特征曲线。对流线分布和压力响应特征曲线的综合分析表明,部分射开井的压力导数曲线出现两条水平直线段。研究了渗透率比、射开厚度比、射孔部位对压力响应特征的影响,结果表明,渗透率比越大,第2条径向流水平直线段出现的时间越早;射开厚度比越小,两条水平直线段的高度差越大;射开部位对压力响应的影响不大。认为渗透率比和射开厚度比对压力响应有较大的影响,是试井解释必须考虑的重要影响因素。

部分去龋法治疗恒磨牙深龋的疗效观察

目的 :探讨部分去龋治疗恒磨牙深龋的临床疗效。方法 :对102颗恒牙深龋进行部分去龋法结合树脂严密充填,随访6个月以上,评价其牙髓存留率及治疗主观感受。结果:随访到的97颗患牙中,90颗充填物完好,牙髓活力正常,治疗成功率为92.8%;79.9%的患者治疗感受为轻度不适或无反应。结论:部分去龋法治疗恒牙深龋,可以减少牙髓暴露的风险,减轻患者治疗时的不适,获得较好的充填治疗效果,值得临床推广。

带横隔板局部开孔沉箱在斜向波作用下的受力研究

基于线性势流假定,对斜向波作用下带横隔板局部开孔沉箱防波堤的水平波浪力进行了理论研究。给出了开孔沉箱法向水平力和横隔板受力的理论计算方法,在极限情况下波浪力的计算结果与文献中的已有结果一致。利用数值算例分析了开孔沉箱总水平力的主要影响因素。开孔沉箱法向总水平力的减小主要集中于结构上半部分波浪影响范围以内。增加单个开孔沉箱的长度有利于减小结构所受总水平波浪力。当波浪入射角或沉箱前开孔墙孔隙影响系数幅值较大时,开孔沉箱横隔板上总水平力的最大值要超过相应的沉箱法向总水平力,此时要注意横隔板的强度问题。