Algorithmic Design for the Examination Arrangement System on a Large Scale for Universities

It is a multifactor optimization problem to arrange examinations on a large scale for universities. In this paper, a kind of grouped optimization algorithm was proposed. A principle about related degree, which plays a core role in realization, was introduced in the algorithm. According to the algorithm, we worked out a set of software correspondingly and applied it to a certain university in Shanghai to arrange examinations. It shows that the algorithm is very effective.

Parameters and Trajectory Overall Optimization Design of the Combined Cycle Engine Reusable Launch Vehicle

Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.

Investigate the Impact of Dimple Size and Distribution on the Hydrothermal Performance of Dimpled Heat Exchanger Tubes

In this study,the primary objective was to enhance the hydrothermal performance of a dimpled tube by addressing areas with low heat transfer compared to other regions.To accomplish this,a comprehensive numerical investigation was conducted using ANSYS Fluent 2022 R1 software,focusing on different diameters of dimples along the pipe’s length and the distribution of dimples in both in-line and staggered arrangements.The simulations utilized the finite elementmethod to address turbulent flowwithin the tube by solving partial differential equations,encompassing Re numbers spanning from 3000 to 8000.The study specifically examined single-phase flow conditions,with water utilized as the cooling fluid.The results of the investigation indicated that increasing the Reynolds number resulted in higher average Nusselt numbers,pressure drops,the overall performance criterion,and a reduction in average thermal resistance across all models analyzed.Notably,both proposedmodels demonstrated improved heat transfer when compared to the conventional model.Out of all the models evaluated,the tube featuring staggered dimples(Model B)demonstrated the most notable improvement in the Nu number.It exhibited an enhancement of approximately twice the value compared to the conventional model.The mean thermal resistance for the tube with dimples in the staggered arrangement(Model B)is 0.0057 k/W,compared to 0.0118 k/W for the traditional model.The maximum overall performance criterion for Model-A-and Model-Bis 1.22 and 1.33,respectively.

Environmental Risks in China and Their Countermeasures

The 13th Five-year Plan period （2016-2020） is a crucial period for environmental protection in China and represents the last chance for the achievement of the environmental objective under the goal of building a well-off society in an all-round manner. During this period of time, China＇ s environment is confronted with the following major risks： risks of environmental quality, human health, ecological security, balanced regional development and international influence. The overall conclusion is that the tendencies of changing eco-environment are complex, problems remain outstanding, and some risks have abated while others have intensified with possible improvements in the future. Future prospects mainly depend on the intensity of actions taken. It is suggested that environmental protection strategy of＂overall optimization＂ be adopted for the 13th Five-year Plan period, i.e. environmental protection requirements should be incorporated into political, economic, social and cultural spheres, so that these areas with major influence on the natural environment will improve and transform towards an environmentally friendly direction and ultimately help achieve the objective of improving eco-environment and people＇s welfare. In order to fundamentally reverse mainstream understanding on environmental protection, it is suggested to define the ＂contradiction between environmental pressures arising from growing economic development and China ＇ s limited and fragile environmental capacity＂ as a major contradiction of Chinese society.

Key Technologies in the Design and Construction of 300 m Ultra-High Arch Dams

Starting with the Ertan arch dam （240 m high, 3300 MW） in 2000, China successfully built a total of seven ultra-high arch dams over 200 m tall by the end of 2014. Among these, the ]inping 1 （305 m）, Xiaowan （294.5m）, and Xiluodu （285.5 m） arch dams have reached the 300 m height level （i.e., near or over 300 m）, making them the tallest arch dams in the world. The design and construction of these 300 m ultra-high arch dams posed significant challenges, due to high water pressures, high seismic de- sign criteria, and complex geological conditions. The engineering team successfully tackled these chal- lenges and made critical breakthroughs, especially in the area of safety control. In this paper, the author summarizes various key technological aspects involved in the design and construction of 300 m ultra- high arch dams, including the strength and stability of foundation rock, excavation of the dam base and surface treatment, dam shape optimization, safety design guidelines, seismic analysis and design, treatment of a complex foundation, concrete temperature control, and crack prevention. The experience gained from these projects should be valuable for future practitioners.

Enhanced thermal stability of VCSEL array by thermoelectric analysis-based optimization of mesas distribution

The thermal stability of a vertical-cavity surface-emitting laser（VCSEL） array is enhanced by redesigning the mesa arrangement. Based on a thermoelectric coupling three-dimensional（3D） finite-element model, an optimized VCSEL array is designed. The effects of this optimization are studied experimentally. Power density characteristics of VCSEL arrays with different mesa configuration are obtained under different thermal stress in which the optimized device shows improved performance. Optimized device also shows better stability from measured spectra and calculated thermal resistances. The experimental results prove that our simulation model and optimization is instructive for VCSEL array design.

Optimal arrangement for pressure measurement points in working chamber of earth pressure balance shield

In order to exactly provide scientific basis for pressure dynamic balance control of working chamber of earth pressure balance shield (EPBS),study on optimal arrangement of pressure measurement points in working chamber was conducted. Based on mathematical description of optimal arrangement for pressure measurement points,fuzzy clustering analysis and discriminant analysis were used to divide pressure regions of nodes on bulkhead. Finally,the selection method of optimal measurement points was proposed,and by selecting d6.28 m EPBS as study object,the case study was conducted. By contrast,based on optimal arrangement scheme of pressure measurement points,through adopting weighted algorithm,the absolute error mean of equivalent pressure of working chamber is the smallest. In addition,pressure curve of optimal arrangement points presents parabola,and it can show the state of pressure distribution on bulkhead truly. It is concluded that the optimal arrangement method of pressure measurement points in working chamber is effective and feasible,and the method can provide basis for realizing high precision pressure control of EPBS.

Surface Magnet Gears with a New Magnet Arrangement and Optimal Shape of Stationary Pole Pieces

In mechanical gear systems, dust, noise, vibration, and tooth wear are generated by frictions among gear teeth, and suppressing friction requires lubrication. Magnetic gears transmit torque by magnetic forces without contact and so avoid contact-related problems. The present paper discusses magnet arrangements and the shape of stationary gear teeth to improve transmission torque in surface magnet type magnetic gear transmission mechanisms.

Studies on the Optimization and Storage Stability of Virgin Coconut Meal Incorporated Instant Sooji Halwa Mix

Virgin Coconut Meal (VCM) was used for the development of instant wheat sooji (semolina) halwa mix with better nutritional attributes. Central composite rotatable design (CCRD) with 2 independent variables (sugar and VCM) and 4 responses (lightness, redness, taste and overall acceptability) was used for the optimisation. VCM incorporated instant halwa mix prepared using optimised levels of ingredients contained moisture 0.95%;fat 26.2%;protein 7.65%;total ash 0.86%;fibre 1.02% and received overall acceptability score of 8.5 on a 9 point hedonic scale providing 523.86 K·cal/ 100g. The changes in quality of stored VCM incorporated instant halwa mix packed in polypropylene (PP, 75 μ) and laminates of metallised polyester (MP, 90 μ) were monitored in order to assess the shelf-life. Instant halwa mix remained stable and acceptable for one year in both the packaging materials under ambient temperature conditions (15℃ - 34℃). However, the rate of lipid peroxidation was found to be slightly higher in PP packed samples as compared to MP packed ones. Fatty acid composition of VCM incorporated instant halwa mix remained practically unchanged during storage. Oleic acid was the major fatty acid present in fat extracted from halwa mix followed by palmitic and lauric acids.

Coupling Characteristics and Control of Dual Mechanical Port Machine with Spoke Type Permanent Magnet Arrangement

Dual mechanical port machine（DMPM）, as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements（STPM-DMPM）, which is one of several types of DMPM, has been of interest recently. The unique coupling characteristics of STPM-DMPM are beneficial to improving system performance, but these same characteristics increase the difficulties of control. Now there has been little research about the control of STPM-DMPM, and this has hindered its practical application. Based on a mathematical model of STPM-DMPM, the coupling characteristics and the merits and demerits of such devices are analyzed as applied to a hybrid system. The control strategies for improving the disadvantages and for utilizing the advantage of coupling are researched. In order to weaken the interaction effect of torque outputs in the inner motor and the outer motor that results from coupling in STPM-DMPM, a decoupling control method based on equivalent current control is proposed, and independent torque control for the inner motor and outer motor is achieved. In order to solve address the problem of adequately utilization of coupling, minimizing the overall copper loss of the inner motor and the outer motor of STPM-DMPM is taken as the optimization objective for optimal control, and the purpose of utilizing the coupling adequately and reasonably is achieved. The verification tests of the proposed decoupling control and optimal control strategies are carried out on a prototype STPM-DMPM, and the experimental results show that the interaction effect of torque outputs in the inner motor and the outer motor can be markedly weakened through use of the control method. The overall copper loss of the inner motor and the outer motor can be markedly reduced through use of the optimal control method, while the power output remains unchanged. A breakthrough in the control problem of STPM-DMPM is accomplished by combining the control methods. Good performance in the control of STPM-DMPM will enhance its practicality, particularly as applied to hybrid systems.

Improved color feature arrangement for mean shift tracking

In order to reduce redundant empty bin capacity arrangement mechanism for mean shift tracking objects in the probability representation, we present a new color feature In the proposed mechanism, the important optimal color, or we call it optimal color vector, is clustered by closing Euclidean distance which happens inside the original RGB color 3-D spatial domain. After obtaining clustering colors from the reference image RGB spatial domain, novel clustering groups substitute for original color data. So the new color substitution distribution is as similar as the original one. And then target region in the candidate frame is mapped by the constructed optimal clustering colors and the cluster Indices. In the final, mean shift algorithm gives a performance in the new optimal color distribution. Comparison under the same circumstance between the proposed algorithm and conventional mean shift algorithm shows that the former has a certain advantage in computation cost.

Application of the Common Offset Seismic Reflection Method to Urban Active Fault Surveys

The method and principle of common offset seismic surveys as well as the field data gathering and processing technique were introduced briefly. Through two urban active fault survey examples in Fuzhou and Shenyang, the efficiency and limitation of using the common offset seismic reflection technique to carry out urban active fault surveys were probed. The results show that this technique has the properties of high resolving power, better reconstruction of subsurface structures, and real-time analyzing and interpretation of investigation results on site. This method can be used to quickly locate objects under investigation accurately in the areas with thinner Quaternary overburdens and strong bedrock interface fluctuations.

低透煤层瓦斯超前排放钻孔布置方式优化研究

目的为有效解决低透气性煤层瓦斯突出问题,有效消除阵列布孔方式带来的瓦斯排放盲区以及对角圆相切布孔方式造成的钻孔数量增加、重复排放等问题。方法通过理论分析,在超前排放钻孔有效排放半径一定的情况下提出阵列菱形法优化超前排放孔的布置方式(R为有效排放半径,煤层走向排放孔的间距为√3R),其钻孔数量约为对角圆相切法的3/4,重复排放面积减少至11%,减少了对角圆相切布孔方式的重复排放面积,减少了钻孔的数量。结果运用COMSOL Multiphysics对阵列菱形法布孔方式进行数值模拟运算,结果表明,阵列菱形法布孔方式排放20 d后,钻孔有效排放半径内整体瓦斯压力低于0.5 MPa,排放100 d后瓦斯压力低于0.30 MPa,卸压效果优于对角圆相切布孔方式的。将阵列法和对角圆相切法两种布孔方式排放100 d时钻孔周围的瓦斯压力分布情况与阵列菱形法布孔方式排放20 d时的分布情况交叉对比,发现阵列菱形法布孔方式卸压速率更快,卸压范围更广。结论提出阵列菱形法设计钻孔布孔方式,并运用COMSOL Multiphysics对3种钻孔布孔方式的卸压情况进行数值模拟运算,对比发现,阵列菱形法钻孔布孔方式比阵列法和对角圆相切法布孔方式更具优势,且在相同时间内卸压速率更快、卸压范围更广,对低透煤层预防瓦斯突出具有重要的意义。

Research on Overall Optimization Technology of Long March 6A Launch Vehicle

On March 29,2022,the Long March 6A launch vehicle developed by the Shanghai Academy of Space-flight Technology successfully made its maiden flight at the Taiyuan Satellite Launch Center.The Long March 6A launch vehicle was China’s first solid bundled rocket.It uses non-toxic and non-polluting propellants,and has a 700 km sun-synchronous orbit carrying capacity of no less than 4.5 t,which is more than 50%higher than that of a LM-4C launch vehicle.During the development of the LM-6A launch vehicle,the matching relationship between systems and the overall performance of the entire rocket improved significantly through continuous overall optimization work.This paper introduces the typical overall optimization work during the development of the LM-6A launch vehicle.

Improvement of Camera Calibration Accuracy Based on Periodic Arrangement Characteristics of Calibration Target Pattern

Conventional camera calibration that employs calibration targets is a commonly used method to acquire a camera’s intrinsic and/or extrinsic parameters. The calibration targets are usually designed as periodic arrays of simple high-contrast patterns that provide highly accurate world coordinate system points and the corresponding image pixel coordinate system points. The existing pixel coordinate extraction algorithms can reach a sub-pixel level; however, they treat each single pattern in one image as an independent individual, which makes it difficult to further improve extraction accuracy. In this paper, a novel method is proposed by utilizing the periodic arrangement characteristics of the calibration target pattern as a global constraint to improve the calibration accuracy. Based on a camera’s pinhole model, the intersection point of two fitted curves is used as an optimized pixel point to replace the initial one. Following the pixel coordinate optimization procedures, experiments were performed using real data from a 3D laser line scanner and a dynamic precision calibration target. Our results show that the relative errors of camera homography matrix elements obtained by the proposed optimization method were reduced compared with the commonly used method. The average coordinate measurement accuracy can be improved by nearly 0.05 mm. It is shown that the proposed optimization method can enhance the camera calibration accuracy, especially when the extracted pixels are of poorer precision. © 2017 Tianjin University and Springer-Verlag Berlin Heidelberg

六塔单索面矮塔斜拉桥拉索设计研究

六塔单索面矮塔斜拉桥是目前我国比较少见的斜拉桥。从斜拉索选型、斜拉索构造、斜拉索锚固和斜拉索减振等角度对六塔单索面矮塔斜拉桥的斜拉索进行了设计与研究。该桥采用抗拉强度标准值为1 860 MPa的钢绞线斜拉索,每根钢绞线的理论直径为15.2 mm。梁端斜拉索通过锚具锚固在预应力混凝土箱梁的隔板齿块上,而在塔端,采用索鞍分丝管形式将斜拉索锚固在桥塔锚固区。斜拉索在梁端采用粘性剪切型阻尼器进行减振,在塔端采用减振圈减振。为了提高斜拉索的使用寿命和耐久性,在钢绞线斜拉索外表面包裹环氧涂层、防腐油脂和高密度聚乙烯(HDPE)保护套。最后结合未知荷载系数法,对斜拉索索力进行了优化设计,优化后的部分索力虽略有增加,但主梁截面弯矩和应力更加趋于平稳,有利于结构受力。

考虑突发事件的三峡闸室编排多阶段动态优化调度

文中以平均船闸闸室浪费率、船舶平均待闸时间和鲁棒性最小为目标函数,建立了突发事件下的三峡闸室编排多阶段动态优化调度模型和算法.结果表明:本研究提升了对突发事件的智能响应,减少了人工干预,提高了船舶过闸效率.

重庆巫溪至陕西镇坪高速公路设计难点及对策措施

为解决山区工程地质条件复杂,受控因素诸多的高速公路建设难题,以重庆巫溪至陕西镇坪高速公路总体设计为例,针对勘测难、设计难、施工难的问题,详细介绍了该类项目勘察设计的重难点及其设计优化策略。结果表明:1)在复杂山区高速公路施工前,精细化总体设计和专业化细部设计显得尤其重要;2)设计时应加强总体协调和方案比选,做好设计优化及专业间统筹衔接;3)加强地质调查,重视复杂山区桥梁、隧道、弃土场及施工便道的动态设计,确保勘察与设计的有机结合;4)通过全面的总体设计和优化设计,确保了工程的顺利进行,也为类似工程提供了宝贵的经验。

基于快速康复理念的整体优化康复方案在全髋关节置换术患者中的应用效果

目的:探讨基于快速康复理念的整体优化康复方案在全髋关节置换术(THA)患者中的应用效果。方法:选取2020年7月—2021年6月于唐山市第二医院行THA治疗的老年肌少症并发髋关节骨性关节炎、股骨头坏死患者96例作为研究对象,随机分为优化康复组(n=48)及传统康复组(n=48)。优化康复组实施基于快速康复理念的整体优化康复方案,传统康复组实施常规康复干预。比较两组干预效果。结果:术后6个月,优化康复组全身肌肉质量、四肢骨骼肌质量、优势手握力提高,且高于同期传统康复组(P<0.05);传统康复组全身肌肉质量、四肢骨骼肌质量、优势手握力较术前无明显变化,差异无统计学意义(P>0.05)。术后6个月,优化康复组腰椎、髋部骨密度提高,且高于同期传统康复组(P<0.05);传统康复组腰椎、髋部骨密度较术前无明显变化,差异无统计学意义(P>0.05)。术后7 d、术后30 d、术后6个月,两组髋关节残疾和骨关节炎预后问卷评分升高,且优化康复组高于传统康复组(P<0.05)。结论:基于快速康复理念的整体优化康复方案在THA患者中的应用效果较好,可提高患者肌肉质量、优势手握力、骨密度,改善髋关节功能。

角色安排与功能优化:我国老年人探访关爱制度研究

建立特殊困难老年人探访关爱制度是推动实现全体老年人享有基本养老服务及健全新时代我国老年人关爱服务体系的重要内容和关键支撑。在国家基本养老服务的宏观范畴和居家养老服务制度网络的交互中精准把握探访关爱制度的要素构成、功能价值及运行逻辑。现时态中尽管从政策层面和制度层面对探访关爱服务进行了整体安排,实际运行中依然存在类型划定、资源整合、方法应用及功能联通等方面的缺失和障碍。从标准体系构建、运行机制协同及服务质量保障等制度层面加以建构,并从规范流程、内优外联和赋能业务等实践层面予以优化,确保其制度红利的充分释放。