SQL or NoSQL—Practical Aspect and Rational behind Choosing Data Stores

Data storage solutions are a crucial aspect of any application, significantly impacting data management and system performance. This article explores the rationale behind utilizing both SQL and NoSQL databases, addressing key questions about when each type is preferable. The background emphasizes the importance of selecting the appropriate database technology to meet specific application requirements. The purpose of this research is to provide a comprehensive guide for choosing between SQL and NoSQL databases based on various factors, including workload characteristics, scalability needs, and consistency requirements. To achieve this, we examine different strategies for implementing SQL and NoSQL databases in large-scale distributed applications and systems. The research method involves a comparative analysis of the features, advantages, and limitations of both database types. We specifically focus on scenarios involving read-heavy versus write-heavy systems and the trade-offs between availability and consistency. The results of this research indicate that SQL databases, with their relational structure and ACID compliance, are ideal for applications requiring complex queries and data integrity. In contrast, NoSQL databases, offering schema flexibility and horizontal scalability, are better suited for managing extensive datasets and high-velocity data ingestion. In conclusion, the selection of a database depends on the specific needs of the application. SQL databases are preferred for transactional systems with complex relationships, while NoSQL databases excel in scenarios demanding flexibility and scalability. The study provides insights into hybrid approaches, leveraging both database types to optimize system performance.

Zhaci and Nuonuo Kids Bookstore

Nuonuo Kids Bookstore is a dreamlike reading kingdom,established by Zhaci and his team with boundless enthusiasm and considerate design.In such a magical space,laughters and exclamations of kids harmonize into the most beautiful melody.Here,they learn to think,feel,love and also be loved.

Key-Value Store Coupled with an Operating System for Storing Large-Scale Values

The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value pair.Various types of studies have been conducted to improve the performance of the key-value store while maintaining its flexibility.However,the research efforts storing the large-scale values such as multimedia data files(e.g.,images or videos)in the key-value store were limited.In this study,we propose a new key-value store,WR-Store++aiming to store the large-scale values stably.Specifically,it provides a new design of separating data and index by working with the built-in data structure of the Windows operating system and the file system.The utilization of the built-in data structure of the Windows operating system achieves the efficiency of the key-value store and that of the file system extends the limited space of the storage significantly.We also present chunk-based memory management and parallel processing of WR-Store++to further improve its performance in the GET operation.Through the experiments,we show that WR-Store++can store at least 32.74 times larger datasets than the existing baseline key-value store,WR-Store,which has the limitation in storing large-scale data sets.Furthermore,in terms of processing efficiency,we show that WR-Store++outperforms not only WR-Store but also the other state-ofthe-art key-value stores,LevelDB,RocksDB,and BerkeleyDB,for individual key-value operations and mixed workloads.

High performance carrier stored trench bipolar transistor with dual shielding structure

We propose a novel high performance carrier stored trench bipolar transistor(CSTBT)with dual shielding structure(DSS-CSTBT).The proposed DSS-CSTBT features a double trench structure with different trench profiles in the surface,in which a shallow gate trench is shielded by a deep emitter trench and a thick oxide layer under it.Compared with the conventional CSTBT(con-CSTBT),the proposed DSS-CSTBT not only alleviates the negative impact of the shallow gate trench and highly doped CS layer on the breakdown voltage(BV),but also well reduces the gate-collector capacitance CGC,gate charge Q_(G),and turn-off loss E_(OFF)of the device.Furthermore,lower turn-on loss E_(ON)and gate drive loss E_(DR)are also obtained.Simulation results show that with the same CS layer doping concentration N_(CS)=1.5×10^(16)cm^(-3),the BV increases from 1312 V of the con-CSTBT to 1423 V of the proposed DSS-CSTBT with oxide layer thickness under gate(T_(og2))of 1μm.Moreover,compared with the con-CSTBT,the C_(GC)at V_(CE)of 25 V and miller plateau charge(Q_(GC))for the proposed DSS-CSTBT with T_(og2)of 1μm are reduced by 79.4%and 74.3%,respectively.With the VGEincreases from 0 V to 15 V,the total QGfor the proposed DSS-CSTBT with T_(og2)of 1μm is reduced by 49.5%.As a result,at the same on-state voltage drop(V_(CEON))of 1.55 V,the E_(ON)and E_(OFF)are reduced from 20.3 mJ/cm^(2)and 19.3 mJ/cm^(2)for the con-CSTBT to8.2 mJ/cm^(2)and 9.7 mJ/cm^(2)for the proposed DSS-CSTBT with T_(og2)of 1μm,respectively.The proposed DSS-CSTBT not only significantly improves the trade-off relationship between the V_(CEON)and E_(OFF)but also greatly reduces the E_(ON).

Numerical Simulation about the Characteristics of the Store Released from the Internal Bay in Supersonic Flow

To understand the influence of the initial release conditions on the separation characteristics of the store and improve it under high Mach number(Ma=4)flight conditions,the overset grid method and the Realizable k−εturbulence model coupled with an equation with six degrees of freedom are used to simulate the store released from the internal bay.The motion trajectory and the attitude angle of the store separation under the conditions of different centroid,velocity,height and control measures are given by the calculated result.Through analysis,the position of the centroid will affect the separation of the store,which needs to be considered in the design.Increasing the launching height is conducive to the separation of the store.If the store has an initial velocity,it can leave the internal bay more quickly and reduce the probability of collision with the wall.Cylindrical rod and slanted aft wall control measures can improve the attitude of the store and make the store fall more smoothly.

Development Mode of Urban Grassroots Libraries under the Background of Lifelong Learning:Inspiration from Idea Stores in London

The urban grass-roots library is an important part of the public cultural service system,and also a place to carry out national reading and lifelong learning,which is of great significance to the construction of a learning society.In this paper,the development and evolution of urban grassroots libraries in China are reviewed,and the current situation and usage issues of grassroots libraries in Beijing are analyzed.Moreover,the development strategy of idea stores in London,UK is studied,and characteristics are summarized,and possible references are sought.In the new era,urban grassroots libraries should integrate into communities with multiple functions and play a more sufficient role in public education,learning and training,and other aspects.

考虑倒箱的Auto Store仓储拣选系统提箱作业优化

为减少Auto Store仓储拣选系统的倒箱作业时间,提高其提箱作业效率,在已知料箱存储状态及订单商品信息的条件下,研究了Auto Store仓储拣选系统提箱作业优化的问题。以提箱作业时间来衡量Auto Store仓储拣选系统作业效率,建立以最短提箱作业时间为目标的整数规划模型,设计启发式算法对模型进行求解,提出问题下界的约束条件及求解方法,同时,通过算例比较启发式算法与理论下界的差异,表明倒箱作业规则对Auto Store仓储拣选系统提箱作业效率影响较大,优化倒箱作业规则,可提高其提箱作业效率,为Auto Store的倒箱作业优化提供了理论支持。

具有高价值密度的农业物联网数据区块链压缩存储方案

针对现有区块链物联网体系主要采用链上存储摘要链下保留原始数据的存储方式中链上无法直接获得真实数据的问题,该研究提出了一种具有高价值密度的农业物联网数据区块链压缩存储方案。首先,边缘服务器将收集的同一批数据聚合到同一批事务中;其次,设计离群值可处理的自适应有损压缩方法,在满足用户保真度要求的前提下降低数据冗余;最后,压缩数据上链,实现区块链上物联网数据的高价值密度存储。与现有方案相比,该方案能提高链上存储真实物联网数据的效率。试验结果表明,在使用自适应压缩方法压缩数据时,针对不同的数据集会自适应选取k值,在满足用户重建精度的前提下,获得良好压缩效果,减少链上存储空间,提高了数据价值密度;相对于风速之类频率较高的数据,温湿度、二氧化碳等变化频率较低的数据可以获得较高的压缩比;当假设正常数据压缩比为10:1时,该方案可节省约85%的链上存储空间,相应的价值密度提高了约85%。该研究可为农产品溯源过程中的物联网数据高效存储提供解决方案,为实现分布式农业物联网数据压缩存储提供技术支持。

诱捕器在储粮害虫治理中的应用现状及展望

在储粮害虫防治中,由于长期、不合理地使用磷化氢和防护剂,导致害虫抗药性的产生。因此,需要开发绿色高效的防治替代方法。将信息素、食物引诱剂和灯光与诱捕器结合诱捕害虫,可实现害虫的大量诱杀和在线监测,在储粮害虫治理中具有很好的应用前景。进一步提高诱捕器的诱捕效率,以及建立诱捕器监测结果与害虫种群发生动态的联系是推广诱捕器应用的技术关键。通过分析诱捕器在储粮害虫治理中应用时存在的问题,提出解决途径,并指出未来研究的方向,以期为诱捕器的开发和应用推广提供参考。

高质量发展形势下广东粮食生产现状、问题与对策

广东是经济强省,也是人口大省,保障粮食安全对促进社会经济高质量发展具有重要作用。通过调研、查阅资料和系统分析,发现广东粮食生产中存在以下几方面问题:人均粮食产量和粮食自给率低、粮食播种面积和单产下降、各地市发展不平衡、种粮普遍亏损和种粮主体老龄化严重。这些问题严重威胁着广东粮食安全和产业高质量发展。在社会经济高质量发展的大背景下,提出保证粮食安全和产业发展的建议:首先是全省一盘棋,制定粤粮提升战略,建立粮食产业综合管理部门,从粮食产业链发展角度,制定约束性发展目标和落实措施;其次是突出重点,补齐各地产能短板,包括口粮为先、水稻为主、稳定水稻面积、增加粮食种植面积和以平均单产低于全省平均的地级市为重点等;三是精准施策,实现“政府要粮安和农民要效益”的协调,包括“藏粮于地”提高土地利用率、“藏粮于技”科技驱动、多措并举实现大面积均衡增产、合理补贴提高种粮效益与积极性,扶持各类农业新型经营主体带动农户同步发展。

基于LSTM算法的玉米籽粒储藏温度预测

为减少储粮损失和虫霉等的发生,该文利用自制试验仓及检测系统检测储藏玉米籽粒不同位置的粮温,分析粮堆温度变化及整个粮堆热量的传递过程。试验结果表明,仓外环境温度对粮温影响较大,仓内粮食温度变化与仓外环境温度变化相比较为滞后,粮堆第一层2号位置温度在检测周期中一直处于较低状态,温度最高位置出现在第四层12号位置。基于粮堆温度变化分析,该文开展了基于长短时记忆网络(LSTM)算法的玉米籽粒储藏粮温预测研究。结果表明:(1)对比预测值与试验值可知,粮堆第一、二、三、四层测试集的粮温准确率分别为0.62、0.89、0.83、0.79;(2)位于粮堆第二层和第三层的预测结果精度较高,试验仓粮堆底层和顶层温度易受环境温度影响,粮堆热量交换速度快,温度变化迅速,导致第一层和第四层预测结果精度偏低。该研究可为粮食储藏温度预测研究提供新思路。

基于MQTT协议的轻量化文本信息分发技术研究

随着卫星通信网络的发展,基于卫星通信网络实现手机、平板电脑等移动通信设备之间的通信成为研究的热点。由于其采用无线电波进行信号传输,且需要经过多个中继站进行信号的转发和处理,导致存在网络延时大、丢包率高以及信道狭窄等问题。针对文本信息在卫星通信网络下的分发过程存在效率低下、可靠性不高的问题,设计一种基于MQTT(Message Queuing Telemetry Transport)协议的轻量化文本信息分发技术。该技术使用MQTT协议作为消息传输协议,在文本信息分发前对MQTT协议进行主题设计、发布订阅机制设计、设备连接设计以及设备心跳设计,确保设备之间的连通性;在文本信息的分发过程中,设计数据校验加密算法、文本信息轻量化处理方法和离线消息存储机制,保证文本信息分发的安全性、可靠性。实验结果表明:相较于传统的基于JSON数据的文本信息分发技术,该技术在提高文本信息分发效率的同时,可确保信息分发的安全性、完整性和稳定性。

水分对消防灭火防护服织物系统辐射热防护性能的影响

现阶段消防灭火服热防护性能评估中,对水分影响的考虑不足。为研究水分在不同织物层中对其热防护性能的影响差异,在低热辐射暴露下,分别在外层、舒适层、外层与舒适层设置不同含水量水平,分别针对直接热暴露、包含热暴露与蓄热释放全程两种情形进行试验测评。研究发现,无论是直接热暴露还是综合考虑蓄热释放的作用,增加外层织物水分含量有利于提升多层织物整体热防护能力,且随着水分含量的增大而上升;舒适层织物润湿则会削弱多层织物整体热防护能力,提高舒适层的吸湿排汗能力,保持其干燥是保持灭火防护服热防护性能的手段之一。外层与舒适层同时润湿时,二者之间呈现交互影响,未来可进一步深入研究。

从“脾藏意”探讨五加减正气散治疗腹泻型肠易激综合征的理论依据

腹泻型肠易激综合征(IBS-D)发病率居高不下,精神心理异常导致的脑-肠轴紊乱是重要致病因素。中医学认为,“脾失健运”“脾不藏意”是病机关键。脾居中焦,为五脏气机之“枢轴”,情志之根本。“脾藏意”包含了认知、情绪、生理等不同内涵,与脑-肠轴密切相关,既是藏象理论的重要组成部分,也是中医情志病与西医心理学互通的桥梁。五加减正气散可通过强脾意、运脾营,多途径、多靶点发挥增强免疫、调节肠道菌群、抗炎止泻、调节内脏高敏等作用。本文从“脾藏意”探讨五加减正气散治疗IBS-D的理论依据,为进一步揭示该经方对脑-肠轴的调控靶点提供理论依据,为从脾论治消化心身疾病提供新的思路与方法。

昆虫对低氧环境的适应性机制研究进展

昆虫需要利用氧气进行有氧呼吸,产生能量,维持正常的生命活动。在储藏环境中,可以利用气调技术控制环境中氧气的占比,以达到防治害虫的目的。然而害虫低氧适应性的发展为这项技术的推广和应用带来挑战。文章围绕低氧对昆虫生长发育、生命活动、生理功能的影响,以及昆虫适应低氧环境的补偿性策略,包括内在调控机制,生物学特性调节,代谢网络重构,基因调控等方面进行了综述。以期为害虫低氧适应性的产生机制提供新的研究线索,为绿色储粮技术的研究及发展提供参考。

基于燕赵精品示范店场景打造的河北省旅游购物消费提振对策

旅游购物是旅游活动的重要因素之一,在拉动旅游消费和促进旅游经济方面发挥的作用不可小视。河北省旅游购物存在一定短板,其在提振旅游消费方面的作用还不够突出。基于旅游购物消费的趋势和河北省旅游购物消费存在的短板,文章提出开办一批燕赵精品示范店,集中推介展示河北各地名优特新消费品,并从场景打造、优化服务、体验提升和保障措施等层面提出对策建议,满足游客购物需求,为经济强省美丽河北建设注入旅游新动能。

面向持久化键值数据库的自适应热点感知哈希索引

针对现有键值数据库存储系统缺乏热点意识,导致系统在高度倾斜的工作负载下性能较差且不可靠,提出了一种自适应热点感知哈希索引模型,该模型基于key值摘要信息实现了一个高性能哈希表。首先,利用key的摘要信息代替key值,压缩key的存储空间,优化哈希表中桶的数据结构;其次,利用CPU的数据级并行技术以及CPU cache line,对哈希表的探查操作进行优化;最后,为解决摘要信息导致key值无法精准比较,需要额外磁盘I/O的问题,设计了一种自适应key值调度算法,该算法根据当前可用内存大小、哈希索引负载以及访问热点情况动态地调整key值的存储位置。在YCSB仿真数据集上进行了实验,实验表明,相较于最先进的哈希表,自适应热点感知哈希索引在相同内存使用率的情况下,将速度提升至1.2倍。

路用蓄盐除冰纤维配比设计及除冰性能确定

为解决道路凝冰问题,基于环保、经济、实用等原则,针对适用于沥青路面主动抗凝冰的蓄盐纤维填料的配合比进行设计,并对其相关性能展开研究。通过基于单纯形重心设计的融冰试验和电导率试验对蓄盐除冰材料配比进行探究,并基于融冰试验和冻粘剪切试验分析其除冰性能。试验结果表明:选用乙酸钠∶乙酸钾∶甲酸钠=7∶2∶1、复合有机盐∶纤维=3∶1为蓄盐纤维各种成分的最佳配合比;在融冰试验中,蓄盐纤维替换率为66%的除冰材料在较高负温下融冰速率能达到1022 g·(h·m 2)-1,表明其融冰性能良好;凝冰后,蓄盐纤维沥青混合料表面冻粘强度比普通沥青混合料下降33%,能够有效降低冻粘强度。基于最佳配合比,新型路用环保蓄盐除冰材料具有良好的融冰能力和除冰降粘功效。

内埋武器机弹分离动态风洞投放试验研究

基于动力学相似的动态风洞投放试验研究了尖拱圆柱体从空腔中分离的气动及运动特性,并创新性地采用快响应压敏漆技术对动态运动模型表面上的压力分布测量进行初步探索研究,试验中探究了不同空腔模型攻角(α=0°,-1.5°,-3°)及弹体在空腔内的不同位置(L_(0)=25 mm,39 mm)对内埋武器机弹分离特性的影响。结果表明:弹体在空腔内的位置对机弹分离运动特性的影响最大,当L_(0)=25 mm时,弹体模型头部区域压力明显高于后部区域压力,产生抬头俯仰力矩,导致弹体模型俯仰角逐渐增大,最终碰撞空腔模型,降低载机攻角并未改变弹体模型碰撞空腔模型的效果。当L_(0)=39 mm时,弹体模型在给定的攻角下均能安全地从空腔中分离。

基于改进型YOLOX的储粮害虫识别技术研究

为平衡储粮害虫图像检测中的速度与精度以获得二者最优结合的目标检测模型,提出并实现了一种基于改进YOLOX网络模型的储粮害虫检测方法。通过引入一种新的GSConv替换标准卷积以减少计算量,结合引入的Res-CBAM注意力机制,提升模型的特征提取能力;引入SiLU激活函数提升模型训练效率;引入双向特征金字塔网络(BiFPN)改善特征融合效果;改进损失函数提高目标框回归稳定性;使用非极大值抑制解决冗余框过剩的问题。试验结果表明:改进后的YOLOX模型计算量减少了31%;检测速度提高了18%,最高可达60 FPS;检测精度提高了6.14百分点,最高可达97.05%。改进的YOLOX模型结合了一阶段算法和二阶段算法的优点,在储粮害虫的智能识别中取得了明显的效果。