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DEVELOPING THE COMBINED KALMAN-EMD ALGORITHM TO PROCESS BLASTING SHOCKWAVE SIGNALS PROPAGATING IN A WATER MEDIUM 开发卡尔曼-EMD 组合算法，处理在水介质中传播的爆破冲击波信号
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.833.sce
Tung Lam Vu
{"title":"DEVELOPING THE COMBINED KALMAN-EMD ALGORITHM TO PROCESS BLASTING SHOCKWAVE SIGNALS PROPAGATING IN A WATER MEDIUM","authors":"Tung Lam Vu","doi":"10.56651/lqdtu.jst.v7.n01.833.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.833.sce","url":null,"abstract":"In experiments deploying underwater blast sensors, measured data is always disturbed, expressed as analog peaks in the obtained signal form. Except for pressure peak pmax, other parameters of an underwater explosion such as positive impulse I+, positive phase duration τ+, negative impulse I- and negative phase duration τ- are difficult or almost impossible to extract from this signal type. This article studies developing an algorithm called Kalman-EMD with the combination of Kalman filter and empirical mode decomposition for processing this signal type. The algorithm is applied in 6 data sets measuring the shockwave pressure of underwater explosions by PCB W138A05 sensors with the same condition that 184 grams of A-IX-2 explosive is detonated underwater. The results show that noise in signals is significantly eliminated. For the blasting parameters of processed signals, which can be compared with theory such as I+ and τ+, although it witnesses a small trade-off when errors of I+ enhance from about 3% to 6%, errors of τ+ are significantly decreased from about over 30% to only about 3%. Especially other pieces of information such as I- and τ- can be extracted from the processed signal so this trade-off can be acceptable. Hence, this algorithm can be applied to denoise and extract parameters from shockwave pressure signals of underwater explosions.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"104 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
DETERMINING SHALLOW WATER BATHYMETRY BY STEREO PHOTOGRAMMETRY TECHNIQUE USING WORLDVIEW-2 IMAGERY 利用 Worldview-2 图像的立体摄影测量技术确定浅水水深图
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.831.sce
Minh Hang Le
{"title":"DETERMINING SHALLOW WATER BATHYMETRY BY STEREO PHOTOGRAMMETRY TECHNIQUE USING WORLDVIEW-2 IMAGERY","authors":"Minh Hang Le","doi":"10.56651/lqdtu.jst.v7.n01.831.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.831.sce","url":null,"abstract":"Bathymetry in shallow-water areas plays an important role in marine environment management, marine economic resource development, and national defense and security. The echo sounding method is currently highly accurate; however, it has to deal with a variety of challenges as a result of the high cost, terrain influence, and meteorological conditions at sea. As remote sensing technology progresses, estimating bathymetry using satellite imagery will help lower measuring costs and expand monitoring coverage, particularly in shallow water, offshore areas, and difficult-to-access areas. In this article, the authors present a technique for determining bathymetry in shallow water regions by utilizing WorldView-2 stereoscopic images. The accuracy of stereoscopic depth measurement using WorldView-2 images is assessed by field depth measurement using the single-beam echo sounder. The study area is Nam Yet Island. The coefficient of determination (R2) between the two datasets (field measurement data and using satellite images) is 0.9. The stereoscopic satellite image method of depth measurement is highly accurate for regions with depths below 5 meters. The accuracy of the stereoscopic measurement decreases as the depth increases by more than 5 meters.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"120 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
ON THE USE OF THE GENERAL BANDWIDTH METHOD TO IDENTIFY DAMPING IN MDOF SYSTEMS 关于使用一般带宽法来识别 mdof 系统中的阻尼问题
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.834.sce
Dinh Huong Vu
{"title":"ON THE USE OF THE GENERAL BANDWIDTH METHOD TO IDENTIFY DAMPING IN MDOF SYSTEMS","authors":"Dinh Huong Vu","doi":"10.56651/lqdtu.jst.v7.n01.834.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.834.sce","url":null,"abstract":"The general bandwidth (GeB) method is one of the methods used for viscous damping identification of structures. In this method, approximate and exact formulas have been studied to estimate the damping ratio from frequency response function (FRF) of the single degree-of-freedom (SDOF) system. However, the applicability of these formulas to estimate the damping in multi degree-of-freedom (MDOF) systems has not been analyzed in detail. This article studies the influence of modal parameters on the accuracy of the GeB method used to identify the viscous damping ratios in MDOF systems. The results compared with the formulas based on the half-power bandwidth (HPB) method show that the GeB method has good efficiency and wide identification range.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141668402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
DEVELOPING SPECIALIZED SOFTWARE FOR PROGRESSIVE COLLAPSE ANALYSIS OF PLANE FRAME STRUCTURES USING THE PLASTIC DAMAGE INDEX 利用塑性损伤指数开发平面框架结构渐进式倒塌分析专用软件
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.835.sce
Van Hoang Vu
{"title":"DEVELOPING SPECIALIZED SOFTWARE FOR PROGRESSIVE COLLAPSE ANALYSIS OF PLANE FRAME STRUCTURES USING THE PLASTIC DAMAGE INDEX","authors":"Van Hoang Vu","doi":"10.56651/lqdtu.jst.v7.n01.835.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.835.sce","url":null,"abstract":"In this study, the authors developed software named Sonar to analyze the progressive collapse of structural elements. This software is capable of assessing the level of damage to each structural component and automatically updating the structural model for subsequent analyses. The software features a user-friendly interface, intuitive graphics, easy input of parameters, and presents computational results in 2D graphics. Through the use of the developed software, damaged structures were analyzed and studied to conclude that considering the progressive collapse of elements based on the plastic damage index serves as a basis for investigating specific design problems to propose more optimal design solutions.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"117 30","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141666671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
STATIC BENDING RESPONSE OF COMPOSITE PLATES RESTING ON VARIABLE ELASTIC FOUNDATIONS 复合板在可变弹性地基上的静态弯曲响应
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.836.sce
Chi Tho Nguyen
{"title":"STATIC BENDING RESPONSE OF COMPOSITE PLATES RESTING ON VARIABLE ELASTIC FOUNDATIONS","authors":"Chi Tho Nguyen","doi":"10.56651/lqdtu.jst.v7.n01.836.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.836.sce","url":null,"abstract":"This article introduces a finite element approach for examining the static bending behavior of composite plates. The method considers the variable mechanical characteristics of plates and utilizes an elastic foundation with varying stiffness values. The plate's calculation expressions and equilibrium equations are derived using the new style shear deformation theory. The article uses a mesh composed of four-node rectangular components to solve the equilibrium equation. Each node in the mesh has six degrees of freedom. The solution's dependability and convergence are confirmed by comparing it with previously published findings. Based on this premise, the study presents numerical findings that examine how various geometric factors, materials, boundary conditions, and elastic foundations affect the static bending behavior of composite panels. This research is a great resource for engineers, providing excellent guidance for the design, production, and utilization of these structures in real-world applications.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":" 591","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141669412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
NAVIER SOLUTION FOR DEFLECTION AND STRESSES ANALYSIS OF FGM SANDWICH PLATE RESTING ON PASTERNAK ELASTIC FOUNDATION 帕斯捷尔纳克弹性地基上 FGM 夹层板挠度和应力分析的纳维解法
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.832.sce
Thanh Huan Duong
{"title":"NAVIER SOLUTION FOR DEFLECTION AND STRESSES ANALYSIS OF FGM SANDWICH PLATE RESTING ON PASTERNAK ELASTIC FOUNDATION","authors":"Thanh Huan Duong","doi":"10.56651/lqdtu.jst.v7.n01.832.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.832.sce","url":null,"abstract":"In this article, the first-order shear deformation theory (FSDT) and Navier’s solution are used to establish analytical solutions for analyzing the deflection and stresses of FGM sandwich plate structures resting on a Pasternak elastic foundation. The top and bottom layers consist of functionally graded materials (P-FGM) that vary according to the exponential law along the thickness direction, while the core layer is composed of a porous material. The boundary condition of the plate is simply supported on all the edges, and the plate is subjected to a sinusoidal distributed load perpendicular to the mid-surface. The reliability of the model is validated through comparison with findings published in reputable journals. The effects of material parameters, geometric dimensions, foundation coefficients, and face-core-face thickness ratios on deflection and stress components of rectangular FGM sandwich plates are investigated in detail in parametric studies.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"5 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141668113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
RESEARCH SOLUTIONS FOR PRECAST CONCRETE REVETMENTS USING ALB-REBAR TO RETAIN CORAL SAND FOR OFFSHORE ISLANDS IN VIETNAM 利用 alb-rebar 预制混凝土护岸，为越南近海岛屿保留珊瑚沙的研究方案
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.830.sce
D. Pham
{"title":"RESEARCH SOLUTIONS FOR PRECAST CONCRETE REVETMENTS USING ALB-REBAR TO RETAIN CORAL SAND FOR OFFSHORE ISLANDS IN VIETNAM","authors":"D. Pham","doi":"10.56651/lqdtu.jst.v7.n01.830.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.830.sce","url":null,"abstract":"Gravity revetment solutions are a popular choice for shore protection at atolls under the harsh conditions of ocean waves. The precast revetment option is preferred to reduce shipping costs for materials and ensure quick construction. This article studied precast concrete revetments with ALB composite material reinforcement and conducted experimental research to determine the shear resistance characteristics of coral sand and the friction characteristics of concrete materials with coral sand. Based on the experimental parameters, the authors calculated the stability of the ALB embankment structure against the effects of wave loads during storms. With experimental data obtained from coral sand samples prepared with equivalent density in the field, the results showed that the stability coefficient of the revetment is significantly higher than the one obtained from the traditional calculation concept.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"110 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
EXPERIMENT TO EVALUATE THE EFFECTIVENESS OF THERMAL REFLECTIVE COATING APPLIED TO CONSTRUCTIONS 评估建筑热反射涂层效果的实验
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.837.sce
D. Vu
{"title":"EXPERIMENT TO EVALUATE THE EFFECTIVENESS OF THERMAL REFLECTIVE COATING APPLIED TO CONSTRUCTIONS","authors":"D. Vu","doi":"10.56651/lqdtu.jst.v7.n01.837.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.837.sce","url":null,"abstract":"Constructions are usually made of materials like reinforced concrete and steel. In hot weather conditions, the reflected thermal radiance in the daytime and the emitted thermal radiance of human activities inside the structure are significantly higher than in the background. Thanks to the temperature difference between them, thermal imaging systems can easily detect or recognize the target. In order to reduce the thermal contrast, it is vital to research and apply the specific coating that can be used to cover the construction and the outside door. On the other hand, there is yet to be a method to evaluate the effectiveness of thermal reflective coating for constructions and mobile targets in Vietnam. Hence, the article has focused on performing the experimental measurement of the thermal difference between two coating materials. The result will also be applied to evaluate and select the effective thermal paint for the protected system.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":" 951","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141668853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
SIMULATION ANALYSIS TO FORECAST PROGRESS AND OPTIMIZE RESOURCE UTILIZATION FOR MATERIAL TRANSPORTATION ACTIVITIES IN THE CONSTRUCTION PROJECT ON PHU QUY ISLAND 对富贵岛建设项目材料运输活动的进度预测和资源优化利用进行模拟分析
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.829.sce
Quang Nam Nguyen
{"title":"SIMULATION ANALYSIS TO FORECAST PROGRESS AND OPTIMIZE RESOURCE UTILIZATION FOR MATERIAL TRANSPORTATION ACTIVITIES IN THE CONSTRUCTION PROJECT ON PHU QUY ISLAND","authors":"Quang Nam Nguyen","doi":"10.56651/lqdtu.jst.v7.n01.829.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.829.sce","url":null,"abstract":"This article presents the main results of using a simulation tool to predict time and optimize the resource utilization for the transportion of materials processes in the construction project on Phu Quy island. A simulation model, which includes activities of material transfer processes, has been established and developed based on the EZStrobe simulation program. Various simulation scenarios with different resource usage options have been analyzed. The simulation results are also compared and evaluated with real-world project data. It indicates that for both productivity, time and cost, the option of using two 50-ton cranes at the dock; two 25-ton cranes at the storage yard and four trucks will be the best solution. The results of the study demonstrated the effectiveness of the simulation program, which may help managers choose the resource allocation plan and apply necessary changes to obtain the optimum results in terms of production and cost efficiency for the transportion of contruction materials on the island.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"104 36","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
RESEARCH ON APPLICATION OF FINITE ELEMENT METHOD TO ANALYZE LOAD TRANSFER EFFICIENCY ACCORDING TO DEFLECTION OF AIRPORT RIGID PAVEMENT 应用有限元法分析机场刚性路面挠度的荷载传递效率研究
Journal of Science and Technique Pub Date : 2024-07-08 DOI: 10.56651/lqdtu.jst.v7.n01.825.sce
Tien Dung Vo
{"title":"RESEARCH ON APPLICATION OF FINITE ELEMENT METHOD TO ANALYZE LOAD TRANSFER EFFICIENCY ACCORDING TO DEFLECTION OF AIRPORT RIGID PAVEMENT","authors":"Tien Dung Vo","doi":"10.56651/lqdtu.jst.v7.n01.825.sce","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v7.n01.825.sce","url":null,"abstract":"The load transfer between adjacent cement concrete slabs at expansion joint locations is affected by many different factors. The load-bearing capacity of the pavement will be limited and even lead to destruction if the load transmission ability of the dowel bars does not meet the requirements. Especially, for airports that have just been put into operation or have been in operation for a long time. In this article, the authors have researched and evaluated the effectiveness of load transfer according to deflection through the application of the 3D finite element method. The model utilizes material parameters and actual airport hard pavement structures and calculates for many types of aircraft commonly operating in Vietnam. Thereby calculating and evaluating the load transfer efficiency (LTE) according to deflection for each specific type of aircraft. The model also visually shows the deformation of the transmission dowel bars and concrete slabs at the expansion joint location. The authors tested the model's reliability through experiments conducted at Tan Son Nhat International Airport which is the largest-scale and oldest airport in Vietnam. The results of calculating LTE from the simulation and experimental models have a small error (3.39%) which shows that the model is highly reliable and can be used for similar research directions without being easily done through traditional methods.","PeriodicalId":476702,"journal":{"name":"Journal of Science and Technique","volume":"116 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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