Lightweight Res-Connection Multi-Branch Network for Highly Accurate Crowd Counting and Localization

Crowd counting is a promising hotspot of computer vision involving crowd intelligence analysis,achieving tremendous success recently with the development of deep learning.However,there have been stillmany challenges including crowd multi-scale variations and high network complexity,etc.To tackle these issues,a lightweight Resconnection multi-branch network(LRMBNet)for highly accurate crowd counting and localization is proposed.Specifically,using improved ShuffleNet V2 as the backbone,a lightweight shallow extractor has been designed by employing the channel compression mechanism to reduce enormously the number of network parameters.A light multi-branch structure with different expansion rate convolutions is demonstrated to extract multi-scale features and enlarged receptive fields,where the information transmission and fusion of diverse scale features is enhanced via residual concatenation.In addition,a compound loss function is introduced for training themethod to improve global context information correlation.The proposed method is evaluated on the SHHA,SHHB,UCF-QNRF and UCF_CC_50 public datasets.The accuracy is better than those of many advanced approaches,while the number of parameters is smaller.The experimental results show that the proposed method achieves a good tradeoff between the complexity and accuracy of crowd counting,indicating a lightweight and high-precision method for crowd counting.

Multi-Branch Fault Line Location Method Based on Time Difference Matrix Fitting

The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network system.In this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location problem.Based on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were established.The time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively utilized.To realize the fault segment location,the least square method was introduced.It was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment location.Then,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location.

Wireless Interference Classification with Low Complexity Multi-Branch Networks

In non-cooperative communication systems,wireless interference classification(WIC)is one of the most essential technologies.Recently,deep learning(DL)based WIC methods have been proposed.However,conventional DL-based WIC methods have high computational complexity and unsatisfactory accuracy,especially when the interference-tonoise ratio(INR)is low.To this end,we propose three effective approaches.Firstly,we introduce multibranch convolutional neural networks(CNNs)for interference recognition.The multi-branch CNN is constructed by repeating a layer that aggregates several transformations with the same topology,and it notably improves the recognition ability for WIC.Our design avoids the carefully crafted selection of each transformation.Unfortunately,multi-branch CNNs are computationally expensive and memory-inefficient.To this end,we further propose Low complexity multibranch networks(LCMN),which are mathematically equivalent to multi-branch CNNs but maintain low computing costs and efficient inference.Thirdly,we present novel loss function,which encourages networks to have consistent prediction probabilities for samples with high visual similarities,resulting in increasing recognition accuracy of LCMN.Experimental results demonstrate the proposed methods consistently boost the classification performance of WIC without substantially increasing computational overhead compared to traditional DL-based methods.

Multi-Branch Deepfake Detection Algorithm Based on Fine-Grained Features

With the rapid development of deepfake technology,the authenticity of various types of fake synthetic content is increasing rapidly,which brings potential security threats to people’s daily life and social stability.Currently,most algorithms define deepfake detection as a binary classification problem,i.e.,global features are first extracted using a backbone network and then fed into a binary classifier to discriminate true or false.However,the differences between real and fake samples are often subtle and local,and such global feature-based detection algorithms are not optimal in efficiency and accuracy.To this end,to enhance the extraction of forgery details in deep forgery samples,we propose a multi-branch deepfake detection algorithm based on fine-grained features from the perspective of fine-grained classification.First,to address the critical problem in locating discriminative feature regions in fine-grained classification tasks,we investigate a method for locating multiple different discriminative regions and design a lightweight feature localization module to obtain crucial feature representations by augmenting the most significant parts of the feature map.Second,using information complementation,we introduce a correlation-guided fusion module to enhance the discriminative feature information of different branches.Finally,we use the global attention module in the multi-branch model to improve the cross-dimensional interaction of spatial domain and channel domain information and increase the weights of crucial feature regions and feature channels.We conduct sufficient ablation experiments and comparative experiments.The experimental results show that the algorithm outperforms the detection accuracy and effectiveness on the FaceForensics++and Celeb-DF-v2 datasets compared with the representative detection algorithms in recent years,which can achieve better detection results.

Proppant transport law in multi-branched fractures induced by volume fracturing

To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.

多分支水平井岩屑运移模型与实验研究

随着多分支水平井及复杂结构井钻井技术的不断发展,井眼清洁技术面临着新的困难和挑战。如何解决复杂地质条件与复杂井型条件下的岩屑床问题,对于判断与处理井下复杂情况是当前钻井工程面临的重要科学问题之一。通过岩屑颗粒受力分析建立了岩屑运移环空临界流速模型;基于室内可视化岩屑运移实验,探究了岩屑运移影响规律。结果表明:井斜角为36°时岩屑临界启动速度最大,携岩最为困难;模型预测结果与实验结果吻合度较好,且基于实例井的预测结果与现场作业情况一致,验证了所建模型的可靠性。该研究可为大位移大井斜井及水平井井眼清洁提供理论依据和技术支持。

水平分支井钻完井技术优化及在渤海油田的应用

随着渤海部分油田进入开发中后期,对低产低效井的治理改造愈加迫切,水平分支井技术是实现低产低效井治理的有效手段,但在实际应用中又面临老井井网密集、防碰问题严重,储层易出砂、井壁稳定性差等难题。针对这些难题,通过钻井轨迹优化,克服井眼碰撞问题;优化井身结构和钻井液体系,以保证钻井安全顺利;完井方面优选完井防砂方式,基于多物理场耦合有限元仿真结果对防砂管柱进行结构优化,设计预置导向器,并下入到分支井眼侧钻点下部,实现井壁全支撑。产能显示,A井产量从作业前的5 m^(3)/d增加至45.2 m^(3)/d,半年后产量仍保持40 m^(3)/d,实现稳定生产。这表明通过钻井轨迹优化及精准控制,并配套水平裸眼段井壁全支撑及充填防砂技术可提高单井产量,实现低产低效井高效治理。

Parameters Optimization of Multi-Branch Horizontal Well Basing on Streamline Simulation

As a highly efficient production method, the technique of multi-branch horizontal well is widely used in low permeability reservoirs, heavy oil reservoirs, shallow layer reservoirs and multi-layer reservoirs, because it can significantly improve the productivity of a single well, inhibit coning and enhance oil recovery. Study on sweep efficiency and parameters optimization of multi-branch horizontal well is at the leading edge of research. Therefore, the study is important for enhancing oil recovery and integral exploitation benefit of oil fields. In many applications, streamline simulation shows particular advantages over finite-difference simulation. With the advantages of streamline simulation such as its ability to display paths of fluid flow and acceleration factor in simulation, the flooding process is more visual. The communication between wells and flooding area has been represented appropriately. This method has been applied to the XS9 reservoir in Daqing Oilfield. The production history of this reservoir is about 10 years. The reservoir is maintained above bubble point so that the simulation meets the slight compressibility assumption. New horizontal wells are drilled following this rule.

Optimization for Hydroforming Loading Paths of Parallel Multi-branch Tubes Based on Grey System Theory

According to characteristic of hydroforming of parallel multi-branch tubes,multi-objective problems were transformed to single objective problem of relational grade comparison by grey system theory.Two different objectives were selected,according to the principle that process parameters were optimal which of grey relational grade were maximum,the optimal loading parameters under different objective condition were obtained,and loading paths were optimized.The results indicated that parallel multi-branch tubes hydroformed under loading paths optimized by grey system theory could meet with the requirement that objective was optimal.And the optimal loading paths under different objectives were different,and the appropriate objective should be selected according to forming characteristic.

四川盆地“三高”气井TAML5级分支井钻完井核心技术

分支井可大幅度地降低油气开发成本,是今后深层、超深层油气开发的主要井型之一。为探索分支井在深层碳酸盐岩气藏的适应性和高效开发的新途径,以中国石油西南油气田在四川盆地高石梯—磨溪区块龙王庙组气藏、灯影组气藏部署的2口分支井(MX023-H1井、GS001-X52井)为例,在综合分析该区块地质特点以及TAML5级完井分支井井身结构设计的基础上,系统进行5级分支井眼钻完井技术先导性试验。现场试验表明:(1)分支连接处均实现了机械+固井密封,满足了后期完井管柱选择性重入条件,达到了TAML5级完井要求;(2)现场施工过程中,壁挂式悬挂器是否成功坐挂是分支井施工成败的关键,应用陀螺测方位判断壁挂式悬挂器坐挂情况的方法准确、可靠,为后期井眼的可选择性重入提供了保障;(3)在分支井眼通井、尾管管柱下入过程中,应用设计的弯管将管柱导入开窗窗口,顺利进入分支井眼,充分证实了弯管导入工艺的准确性和可靠性;(4)实践细化形成了分支井眼开窗、通井、套管入窗、套管下入、壁挂式悬挂器坐挂等系列规范化操作流程。结论认为,分支井是今后油气田降低钻井成本、提高采收率的重要技术手段,所形成的一套适合“三高”气井的分支井钻完井技术,将进一步加快我国深层、超深层油气勘探开发的步伐,有助于能源安全的保障和“双碳”目标的实现。

注水解堵工艺在三交区块煤层气多分支水平井中的应用研究

三交区块山西组煤层为中低渗、中等强度中阶煤储层,主力开发井型为多分支水平井。部分水平井在排采过程中因制度管控不当、停电或设备故障等原因产生储层压力波动,导致煤层大量吐粉或坍塌,造成井眼堵塞,进而导致产量断崖式下降,产能无法有效释放,制约了区块的效益开发。结合地质、工程、排采3方面进行动态研究分析,针对井眼堵塞情况,创新开展注水解堵工艺和技术研究,利用水力压裂原理对堵塞部位进行疏通,并在现场施工时加以应用,效果显著。同时,指出该项工艺操作性强、效率高、成本低,且解堵后产量回升较快,可广泛应用于实际生产过程,为煤层气多分支水平井稳产上产提供技术支撑。

淮南潘二矿西四采区灰岩水害地面区域治理技术研究与应用

随着煤炭资源开采,采煤深度也在不断增加,灰岩水害对煤矿安全的威胁也越加严重。以淮南潘二煤矿西四采区为研究对象,为保障A组煤的正常开采,对煤层底板采用多分支水平井注浆技术进行超前治理,文章以D5孔组为例,针对治理区域地质概况研究分析工程的技术难点,并提出应对措施。

煤层底板多分支水平井渗透注浆扩散规律数值模拟研究

多分支水平井注浆堵水技术在矿井水害治理工程中应用很广泛,但深部地层注浆扩散范围缺乏定量表征方法,分支井水平间距、埋深设计因此缺乏理论依据。本文针对多分支水平井渗透注浆工艺,满足考虑岩层渗透率各向异性和水泥浆液、孔隙水两相渗流行为,构建了渗透注浆扩散的数值模型和简化的扩散半径理论模型,并结合实际工程案例开展了渗透注浆浆液扩散数值模拟工作。结果表明,各向异性地层中渗透浆液扩散范围呈现椭圆形,椭圆长轴沿着渗透率较大的顺层方向,椭圆短轴则垂直于层理面方向,为分支井间距、埋深设计和渗透注浆关键参数优化提供了参考依据。

低压低渗煤层气多分支水平井开发关键技术研究——以沁水盆地郑庄区块15号煤层为例

沁水盆地太原组15号煤层总体低压低渗低饱和,煤储层相对较薄,地质条件复杂,煤层气井产量普遍偏低。以沁水盆地郑庄区块为研究对象,依据本区15号煤层LDP-22H多分支水平井的成功开发经验,全面论述低压低渗煤储层煤层气钻完井工艺、标志层判定、井眼轨迹控制等关键技术。结果表明:采用钻井-录井-测井一体化地质导向技术可以有效卡准目的煤层,同时实时修正钻头轨迹,煤层平均钻遇率在97%以上,极大地提升了煤层有效进尺。865 d的排采实践表明,LDP-22H多分支水平井日产气量突破15万m^(3),日产气量稳定在8万m^(3)左右,全程累计产气量为2091.5469.3万m^(3),实现了超高产和稳产,标志着多分支水平井在低压低渗煤储层煤层气高效开发上有较好的适用性。另一方面,多分支水平井要优化井位,加强水平井底部位排采能力,稳定压降速率,减小对煤储层渗透率敏感性伤害,提高排采的连续性,减少停泵和检修作业频次,保证产能的延续性。

基于改进YOLOX算法的交通标志检测研究

为进一步提升交通标志图像视觉检测算法的性能,本文提出了一种改进的YOLOX_M算法.首先为YOLOX_M构建了新的特征融合网络Multi-branch FPN,该网络通过多分支结构提取模型底层的特征信息,并通过FPN进行特征融合,可进一步提高模型利用特征的能力.其次,在YOLOX_M检测头引入的Alpha-GIoU损失函数,可以更好地应用于带噪声的边界框,提高边界框的回归精度.实验表明,改进后的YOLOX_M模型在数据集TT100K上的mAP提高了1.8%,具备较好的检测性能.本文研究结果对交通标志检测具有一定的参考价值.

基于物性差异的低渗礁灰岩多分支水平井酸化设计

针对低渗灰岩A油藏多分支井1M初期生产指标不及预期,为满足海上少井高产需求,设计采用连续油管酸化释放1M井产能。研究表明,A油藏为生物礁(滩)灰岩储层,以粒间溶孔为主,储层非均质性强,连通性较差,裂缝弱发育,探井酸化效果好。该井实钻水平段3036m,产液指数低于同期其它开发井,井底存在污染的可能性高。结合室内实验,优选胶凝酸体系,建议采用连续油管酸化,根据水平段不同小段物性变化设计各段用酸强度,解除污染,降低水平段干扰,实现均匀布酸,预计增产倍比1.5~2.0倍。

海上油田多分支井完井新技术应用

E油田现处于开发初期,但油田投产以来,生产井递减快、稳定产量低、高部位生产井能量亏空较大、采油速度慢。为进一步探索提高油田产能的方式,油藏部门尝试多分支水平井进行先导试验开发,投产初期增产效果显著,但多数分支井初期效果较好,后期可能出现井壁坍塌而失去供液能力。分析认为初期分支井眼保持较完整,因分支井未采取防砂完井措施,后续整体产能受影响。本井提出筛管一体化分支井独立筛管防砂方案,该方案可实现主、分支井眼防砂及分支井眼存在支撑、不易坍塌,该分支井完井技术在海上油田成功应用,为后续同类型井完井奠定基础。

煤矿采动区地面L型瓦斯抽采多分支井钻进关键技术研究

淮北矿区各煤矿采动区瓦斯威胁突出,为解决井下工作面采掘期间卸压瓦斯抽采难题,结合井下及常规地面瓦斯抽采技术,考虑到使井眼覆盖到更大抽采面积,以满足抽采需求,提出地面L型多分支井瓦斯抽采技术。针对地面L型瓦斯抽采多分支井成井质量影响抽采效果的问题,在许疃煤矿某工作面开展地面L型瓦斯抽采多分支井高效钻进技术研究。通过井位层位优化布设、井身结构及井眼轨迹优化设计、套管侧钻开窗技术、井眼轨迹精确控制技术、筛管悬挂完井技术等关键技术研究,形成地面L型瓦斯抽采多分支井成井技术,充分利用煤层采动卸压效应,提高回采工作面瓦斯抽采效率,有效解决井下采掘衔接紧张及瓦斯制约安全生产矛盾。

煤层气钻井技术的经济性分析

目前中国煤层气开发主要集中在低渗煤储集层区域,采用的钻井技术主要包括两种:一是常规直井技术,二是多分支水平井技术。基于两种钻井技术,首先在不考虑产能接替的情况下,针对相同井控面积对全直井方案和全多分支水平井方案进行比较;然后在考虑产能接替的情况下,针对相同设计产能对全直井方案和混合井型方案进行比较。采用投资回收期法和净现值法计算了各个方案在不同煤层气目标区实施后的经济评价指标,比较分析了两种钻井技术在未来中国煤层气开发中的技术经济潜力。认为,采用常规直井技术可以实现一定经济效益,是目前乃至今后一段时间的首选技术;多分支水平井技术更加适合低渗煤储集层开发,可以大幅提高煤层气产量,但钻井投资过高,风险较大,需要在钻井设备和技术人员逐步实现本土化后,再进行推广使用。

多分支水平气井产能预测方法及其应用

多分支水平井能控制更大的储量面积,大幅度地提高油气藏采收率。为此,提出了考虑储层各向异性、断层和实际钻井轨迹影响的多分支水平气井产能预测方法。利用该模型分析了气藏中多分支水平井井型参数(分支长度、分支角度、分支数目)对单井产能的影响。结论表明:分支井筒与主井筒间的干扰以及分支井筒之间的互相干扰是影响多分支水平气井产能的主要因素;在实际应用中应采取4分支以上的分支数目,分支角度应不小于30°,应根据气藏需求选用尽可能大的分支长度。