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Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test 被引量:1
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作者 Wu Houli Guo Endong +2 位作者 Wang Jingyi Dai Xin Dai Chenxi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期163-178,共16页
As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much attention.This paper presents shaking table test research on water supply pipes installed in a full-scal... As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much attention.This paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame structure.Different material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic performance.Floor response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical simulation.The acceleration response and displacement response of different combinations are compared.The results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes. 展开更多
关键词 water supply pipe different materials shaking table test amplification factor seismic fragility
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Prevalence of Enteric Pathogens Associated with Infections among Table Egg Consumers in Some Primary Health Establishments in the Center Region of Cameroon
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作者 Mariane Lucie Ngueguim Bernard Viban Tangwa +2 位作者 Victor Ngu Ngwa Albert Ngakou Abdoulmoumini Mamoudou 《Advances in Infectious Diseases》 CAS 2024年第3期606-619,共14页
Method: In Cameroon limited data are available regarding the prevalence of enteric bacteria associated with table egg consuming infections. As such, a situational-based study was performed in patients with complains o... Method: In Cameroon limited data are available regarding the prevalence of enteric bacteria associated with table egg consuming infections. As such, a situational-based study was performed in patients with complains of stomach disorders after egg consumption. Data related to sociodemographic characteristics and other factors were collected using a structured based questionnaire. Stool culture of utmost importance in stomach disorders patients and serum were collected for typhoid serological test. Results: A total of 207 participants took part in the survey, Results indicated nontyphoidal Salmonella infections were highest in the 3 areas of study with Mfoundi (73.44%) having the highest level of infection compared to other bacterial infection. other enteric bacteria associated to this infection were E. coli serotype 157, Aeromonas, Citrobacter freundii, Enterobacter cloaca and typhi salmonella. Meanwhile salmonelosis caused by typhic salmonella had highest prevalence in the Lekie Division (13.11%) as a result of poor hygienic practices associated with the conservation and preparation of eggs, Stool culture was observed to detect more positive cases in the diagnosis of typhoid fever than Widal test, but with no statistically significant (p > 0.05) difference between the stool culture and Widal test in the 3 areas of study. Conclusion: this study revealed that egg consumers are pruned to enteric bacterial and salmonella infections depending on how and where egg is consumed. 展开更多
关键词 Enteric Pathogens table Eggs Consumption Center Region Cameroon
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Accelerated generation of holograms with ultra-low memory symmetrically high-compressed look-up table
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作者 杨燕 朱建英 +1 位作者 孙敏远 毕勇 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期466-471,共6页
Computer-generated holography technology has been widely applied,and as research in this field deepens,the demand for memory and computational power in small AR and VR devices continues to increase.This paper presents... Computer-generated holography technology has been widely applied,and as research in this field deepens,the demand for memory and computational power in small AR and VR devices continues to increase.This paper presents a hologram generation method,i.e.,a symmetrically high-compressed look-up table method,which can reduce memory usage by50%.In offline computing,half of the basic horizontal and vertical modulation factors are stored,halving the memory requirements without affecting inline speed.Currently,its potential extends to various holographic applications,including the production of optical diffraction elements. 展开更多
关键词 computergenerated hologram look-up table HOLOGRAPHY
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The Periodic Table of Primes
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作者 Han-Lin Li Shu-Cherng Fang Way Kuo 《Advances in Pure Mathematics》 2024年第5期394-419,共26页
Over millennia, nobody has been able to predict where prime numbers sprout or how they spread. This study establishes the Periodic Table of Primes (PTP) using four prime numbers 2, 3, 5, and 7. We identify 48 integers... Over millennia, nobody has been able to predict where prime numbers sprout or how they spread. This study establishes the Periodic Table of Primes (PTP) using four prime numbers 2, 3, 5, and 7. We identify 48 integers out of a period 2×3×5×7=210 to be the roots of all primes as well as composites without factors of 2, 3, 5, and 7. Each prime, twin primes, or composite without factors of 2, 3, 5, and 7 is an offspring of the 48 integers uniquely allocated on the PTP. Three major establishments made in the article are the Formula of Primes, the Periodic Table of Primes, and the Counting Functions of Primes and Twin Primes. 展开更多
关键词 PRIMES COMPOSITES the Periodic table of Primes
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Opinions of Students on the Contribution of the DIVA 3D Virtual Dissection Table to the Teaching of Anatomy at the Faculty of Medicine and Odontostomatology of Bamako
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作者 Abdoulaye Kanté Tata Touré +8 位作者 Ousmane Toumany Chérif Haidara Uhl Jean François Mariam Daou Mamadou A. Keita Bakary Keïta Bréhima Bengaly Drissa Traoré Adégné Togo Nouhoum Ongoïba 《Forensic Medicine and Anatomy Research》 2024年第2期13-25,共13页
Objective: Study the contribution of the DIVA 3D dissection table in the teaching of anatomy at the Faculty of Medicine and Odontology of Bamako. Material and Methods: This was a qualitative study carried out from Nov... Objective: Study the contribution of the DIVA 3D dissection table in the teaching of anatomy at the Faculty of Medicine and Odontology of Bamako. Material and Methods: This was a qualitative study carried out from November 1 to December 30, 2023 at the clinical and morphological anatomy laboratory of the Faculty of Medicine and Odontostomatology of Bamako. Included in this study were students who participated in practical and tutorial sessions. The variables studied during this study were: the previous performance of dissection on a cadaver by the students, the opinion of the students on dissection on a cadaver, the replacement of dissection on a cadaver by virtual dissection in the absence of a body, the level student satisfaction. Results: We surveyed 130 participants. The average age was 22 ± 0.2 years with extremes of 17 and 29 years. 95.3% of participants were students. According to 66.7% of participants, virtual dissection is a good palliative in the absence of a corpse. 95.3% of participants found using the virtual dissection table easy with an average of 7.88 ± 1.4. The overall assessment was well rated by 99.3% of participants. Conclusion: According to the results of this study, the virtual dissection table should be improved by integrating commented videos. The use of the DIVA 3D virtual dissection table during practical and tutorial sessions is well appreciated by the students. We believe that the teaching of anatomy using 3D digital technology should be included in the study programs of the Faculty of Medicine and Odontostomatology. 展开更多
关键词 Student Opinion CONTRIBUTION DIVA 3D Virtual Dissection table Anatomy Teaching FMOS
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Improving Video Watermarking through Galois Field GF(2^(4)) Multiplication Tables with Diverse Irreducible Polynomials and Adaptive Techniques
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作者 Yasmin Alaa Hassan Abdul Monem S.Rahma 《Computers, Materials & Continua》 SCIE EI 2024年第1期1423-1442,共20页
Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4))... Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness. 展开更多
关键词 Video watermarking galois field irreducible polynomial multiplication table scene selection adaptive thresholding
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Evaluation of the effects of EPS composite soil replacement on the dynamic performance of caisson structure using shaking table tests
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作者 Gao Hongmei Ji Zhanpeng +3 位作者 Zhang Xinlei Zhang Shushan Wang Zhihua Shen Guangming 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第4期829-843,共15页
The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The ma... The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The macro phenomena of the two different foundation models are described and analyzed.The effects of the replacement of EPS composite soil on seismic-induced liquefaction of backfill and the dynamic performance of a caisson structure are evaluated in detail.The results show that the excess pore water pressure generation in the CES is significantly slower than that in the CSS during the shaking.The dynamic earth pressure acting on the caisson has a triangular shape.The response of horizontal acceleration,displacement,settlement,and rotation angle of the caisson in the CES is smaller than that in the CSS,which means the caisson in the CES has a better seismic performance.Furthermore,the out-of-phase phenomenon between dynamic earth thrust and inertial force in the CES is more obvious than that in the CSS,which is beneficial to reduce the lateral force and improve the stability of the caisson structure. 展开更多
关键词 EPS composite soil foundation Caisson-type quay wall shaking table test phase difference rotation angle
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Numerical analysis on seismic performance of underground structures in liquefiable interlayer sites from centrifuge shaking table test
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作者 Yan Guanyu Xu Chengshun +2 位作者 Zhang Zihong Du Xiuli Wang Xuelai 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第4期781-798,共18页
When an underground structure passes through a liquefiable soil layer,the soil liquefaction may pose a significant threat to the structure.A centrifuge shaking table test was performed to research the seismic response... When an underground structure passes through a liquefiable soil layer,the soil liquefaction may pose a significant threat to the structure.A centrifuge shaking table test was performed to research the seismic response of underground structures in liquefiable interlayer sites,and a valid numerical model was obtained through simulation model test.Finally,the calibrated numerical model was used to perform further research on the influence of various distribution characteristics of liquefiable interlayers on the seismic reaction of underground structures.The key findings are as follows.The structure faces the most unfavorable condition once a liquefiable layer is located in the middle of the underground structure.When a liquefiable layer exists in the middle of the structure,the seismic reactions of both the underground structure and model site will increase with the rise of the thickness of the liquefiable interlayer.The inter-story drift of the structure in the non-liquefiable site is much smaller than that in the liquefiable interlayer site.The inter-story drift of the structure is not only associated with the site displacement and the soil-structure stiffness ratio but also closely associated with the slippage of the soil-structure contact interface under the condition of large deformation of the site. 展开更多
关键词 centrifuge shaking table test underground structure liquefiable interlayer sites seismic response validation of numerical model
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A novel control strategy for reproducing the floor motions of high-rise buildings by earthquake-simulating shake tables
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作者 Yuteng Cao Zhe Qu Xiaodong Ji 《Earthquake Research Advances》 CSCD 2024年第1期67-75,共9页
To enable the experimental assessment of the seismic performance of full-scale nonstructural elements with multiple engineering parameters(EDPs),a three-layer testbed named Nonstructural Element Simulator on Shake Tab... To enable the experimental assessment of the seismic performance of full-scale nonstructural elements with multiple engineering parameters(EDPs),a three-layer testbed named Nonstructural Element Simulator on Shake Table(NEST)has been developed.The testbed consists of three consecutive floors of steel structure.The bottom two floors provide a space to accommodate a full-scale room.To fully explore the flexibility of NEST,we propose a novel control strategy to generate the required shake table input time histories for the testbed to track the target floor motions of the buildings of interest with high accuracy.The control strategy contains two parts:an inverse dynamic compensation via simulation of feedback control systems(IDCS)algorithm and an offline iteration procedure based on a refined nonlinear numerical model of the testbed.The key aspects of the control strategy were introduced in this paper.Experimental tests were conducted to simulate the seismic responses of a full-scale office room on the 21^(st)floor of a 42-story high-rise building.The test results show that the proposed control strategy can reproduce the target floor motions of the building of interest with less than 20%errors within the specified frequency range. 展开更多
关键词 Shake table test Nonstructural element High-rise building Open-loop IDCS algorithm Off-line iteration
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Pre-training transformer with dual-branch context content module for table detection in document images
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作者 Yongzhi LI Pengle ZHANG +2 位作者 Meng SUN Jin HUANG Ruhan HE 《虚拟现实与智能硬件(中英文)》 EI 2024年第5期408-420,共13页
Background Document images such as statistical reports and scientific journals are widely used in information technology.Accurate detection of table areas in document images is an essential prerequisite for tasks such... Background Document images such as statistical reports and scientific journals are widely used in information technology.Accurate detection of table areas in document images is an essential prerequisite for tasks such as information extraction.However,because of the diversity in the shapes and sizes of tables,existing table detection methods adapted from general object detection algorithms,have not yet achieved satisfactory results.Incorrect detection results might lead to the loss of critical information.Methods Therefore,we propose a novel end-to-end trainable deep network combined with a self-supervised pretraining transformer for feature extraction to minimize incorrect detections.To better deal with table areas of different shapes and sizes,we added a dualbranch context content attention module(DCCAM)to high-dimensional features to extract context content information,thereby enhancing the network's ability to learn shape features.For feature fusion at different scales,we replaced the original 3×3 convolution with a multilayer residual module,which contains enhanced gradient flow information to improve the feature representation and extraction capability.Results We evaluated our method on public document datasets and compared it with previous methods,which achieved state-of-the-art results in terms of evaluation metrics such as recall and F1-score.https://github.com/Yong Z-Lee/TD-DCCAM. 展开更多
关键词 table detection Document image analysis TRANSFORMER Dilated convolution Deformable convolution Feature fusion
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Impact of water table on hierarchically nested groundwater flow system
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作者 Jun Zhang Rong-zhe Hou +2 位作者 Kun Yu Jia-qiu Dong Li-he Yin 《Journal of Groundwater Science and Engineering》 2024年第2期119-131,共13页
Water table configuration gives rise to hierarchically nested groundwater flow systems.However,there remains a lack of comprehensive understanding regarding the controlling factors of water table and its impact on flo... Water table configuration gives rise to hierarchically nested groundwater flow systems.However,there remains a lack of comprehensive understanding regarding the controlling factors of water table and its impact on flow systems.Moreover,it remains challenging to identify characteristics of water table space variation through limited groundwater observations at the regional scale.Based on two ideal two-dimensional cross-section analytical models,this study presents a simplified approach to preliminarily assess the nonlinear interactions between water table variation and three driving factors:Topography,geol-ogy and climate.Two criteria,C1 and C2,are utilized to address issues at different scales ranging from basin to local:(i)the influence of various factors on water table configuration;and(ii)the influence of water table on groundwater flow pattern.Then,the Ordos Plateau is taken as an example to explore the role of the water table in nested groundwater systems using the provided approach and criterion.The applica-tion of this approach in the Ordos Plateau demonstrates its appropriateness as a practical method for prelim-inarily determining the characteristics of water table configuration and its impact on flow systems.The study explores the mechanism influencing spatial variation in the water table and improves understanding of the interaction between topography,geology,and climate on groundwater flow patterns. 展开更多
关键词 Water table configuration Groundwater flow pattern Analytical models Top boundary condi-tions Ordos Plateau
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Determination method of permafrost table in seasonal frozen soil areas under“Water-Heat-Salt”coupling
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作者 WANG Fang YANG Zhong +1 位作者 LIU Kai LU Chang-long 《Journal of Mountain Science》 SCIE CSCD 2023年第11期3266-3282,共17页
The permafrost table is an important index for the design and construction of roads in cold regions,so it is necessary to find a convenient,accurate and fast judgment method to determine the permafrost table.In this s... The permafrost table is an important index for the design and construction of roads in cold regions,so it is necessary to find a convenient,accurate and fast judgment method to determine the permafrost table.In this study,a three-field coupled model was established based on the hydrothermal salt coupling within the permafrost and the similarity theory,and the changes of the permafrost table under different temperature,moisture and salt conditions were numerically simulated by considering the transient temperature change and the influence of the permafrost layer on the seasonally thawed layer.In addition,an accelerated permafrost table test method was designed based on the time-domain variation and hydrothermal salt coupling by the similarity theory,which rapidly simulated the permafrost table change under different temperatures,moisture,and salts in the natural environment.Comparing the simulation and test results with the measured values in the field,the errors are less than 3%,which verified the feasibility of the method for determining the permafrost table,and the simulated results are better than the test results.Results show that the results of determining the permafrost table with a single index have different degrees of deviation,and the permafrost table obtained by the temperature index is the most accurate in general,and it is more accurate to use the average value of the three indexes as the permafrost table compared with a single index. 展开更多
关键词 Permafrost table Hydrothermal salt coupling Seasonally thawed layer Numerical simulation Accelerated test
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Seasonal Effect on Weather Elements on Water Table Fluctuation in Potable Wells in Kono District, Eastern Sierra Leone
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作者 Richard Tamba Simbo Alhaji Brima Gogra +1 位作者 Yahaya Kudus Kawa Paul Juana Moiwo 《Open Journal of Applied Sciences》 2023年第11期2198-2209,共12页
The study investigated the seasonal effects of weather elements on water table fluctuations in drinking wells in Nimikoro and Tankoro Chiefdoms in Kono District, Eastern Sierra Leone. The study specifically determined... The study investigated the seasonal effects of weather elements on water table fluctuations in drinking wells in Nimikoro and Tankoro Chiefdoms in Kono District, Eastern Sierra Leone. The study specifically determined the trends in precipitation, air temperature and relative humidity relative to water table depth and water volume in both manually dug and mechanically drilled water wells in the chiefdoms. The key objective was to provide a clear guide on sustainable well development and operation in the study area and beyond. To do so, the depth of each well was taken and the water table measured. Also, data on key weather elements such as precipitation, air temperature and relative humidity were collected on the 15<sup>th</sup> of every month for a period of one year. The data were analyzed on Excel, SPSS and ArcGIS platforms for monthly and seasonal trends in the time-space fabric. The results showed that the depth to water table was high in the dries (small well water volume) and low in the rains (large well water volume) for both manually dug and mechanically drilled wells. Well water temperature increased as temperature increased during the dry season but decreased as temperature decreased during the rainy season. The study showed that weather elements such as precipitation and temperature had direct impact on groundwater availability. This is critical for groundwater development and management in the study area and in Sierra Leone at large. 展开更多
关键词 GROUNDWATER Water table Relative Humidity PRECIPITATION Temperature
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Displaying Water Table Levels, Flow Direction for Predicting Construction Techniques Using Geographic Information: Case Study of Kumba (South West, Cameroon)
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作者 Benjamin Bahel Blaise Bayiha Ngwem +5 位作者 Cyrille Sigue Bepuaka Ekuka Martin Molua Ndive Alain Christian Bock Hyeng Emmanuel Yamb Sébastien Owona 《Open Journal of Civil Engineering》 2023年第2期388-398,共11页
The rapid economic growth of the town present the matter of water issue as a problem to human life human life, construction life, agriculture, etc. This study is to predict techniques of foundation construction throug... The rapid economic growth of the town present the matter of water issue as a problem to human life human life, construction life, agriculture, etc. This study is to predict techniques of foundation construction through the displaying of the water table at the flow direction in the town of Kumba and GIS. It is characterized by a significant research question which is the level of fall and rise in groundwater levels within the town of Kumba and this influence on choice of types of foundation in construction. This study is directed to decision makers, and technicians of the construction field to develop policies facilitating the supervision when building construction foundation by informing about water level depth and its flow direction in the town. To achieve this, depths of static water levels were measured in over 200 randomly selected hand-dug wells in Kumba, after their geolocation and data were collected during the dry season (November and March 2017) and during the rainy season (between April and October 2017). Data were analyzed and treated using Microsoft Excel and GIS software us as Golden Surfer, Global Mapper, and ArcGIS. The results show variations of water level and those areas that may threaten foundation construction. Quarter as Kumba Station, Mile 1, Bulletin Street (Fongong Quarter), and parts of Fiango show that water table is to deep water and proper for the shallow foundation but very hard for water supply through borehole. Groundwater flow direction was revealed to be towards the south and southeastern parts of Kumba. The significant of the study is to propose to the technician the direct application on the field of chosen types of foundations according to the quarter and proposed groundwater supply possibilities. 展开更多
关键词 GIS Prediction Water table Level Kumba FOUNDATION
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Hash Table Assisted Efficient File Level De-Duplication Scheme in SD-IoV Assisted Sensing Devices
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作者 Ghawar Said Ata Ullah +4 位作者 Anwar Ghani Muhammad Azeem Khalid Yahya Muhammad Bilal Sayed Chhattan Shah 《Intelligent Automation & Soft Computing》 2023年第10期83-99,共17页
The Internet of Things(IoT)and cloud technologies have encouraged massive data storage at central repositories.Software-defined networks(SDN)support the processing of data and restrict the transmission of duplicate va... The Internet of Things(IoT)and cloud technologies have encouraged massive data storage at central repositories.Software-defined networks(SDN)support the processing of data and restrict the transmission of duplicate values.It is necessary to use a data de-duplication mechanism to reduce communication costs and storage overhead.Existing State of the art schemes suffer from computational overhead due to deterministic or random tree-based tags generation which further increases as the file size grows.This paper presents an efficient file-level de-duplication scheme(EFDS)where the cost of creating tags is reduced by employing a hash table with key-value pair for each block of the file.Further,an algorithm for hash table-based duplicate block identification and storage(HDBIS)is presented based on fingerprints that maintain a linked list of similar duplicate blocks on the same index.Hash tables normally have a consistent time complexity for lookup,generating,and deleting stored data regardless of the input size.The experiential results show that the proposed EFDS scheme performs better compared to its counterparts. 展开更多
关键词 Hash table de-duplication linked list IoT sensing devices
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Shaking table test and cumulative deformation evaluation analysis of a tunnel across the hauling sliding surface
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作者 Lifang Pai Honggang Wu Xu Wang 《Deep Underground Science and Engineering》 2023年第4期371-393,共23页
To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical ca... To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas. 展开更多
关键词 magnification of Arias intensity plastic effect coefficient seismic action seismic cumulative failure effect shaking table test tunnel engineering
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基于幂指数法的地震模拟振动台频域前馈补偿方法 被引量:1
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作者 纪金豹 杨森 胡宗祥 《地震工程学报》 CSCD 北大核心 2024年第1期199-206,共8页
针对地震模拟振动台受到系统和试件非线性等因素影响,导致波形再现精度不高的问题,提出基于幂指数法的地震模拟振动台频域前馈补偿方法以提高振动台的控制效果,通过数值仿真和实际振动台试验对该方法的控制性能进行研究。研究结果表明:... 针对地震模拟振动台受到系统和试件非线性等因素影响,导致波形再现精度不高的问题,提出基于幂指数法的地震模拟振动台频域前馈补偿方法以提高振动台的控制效果,通过数值仿真和实际振动台试验对该方法的控制性能进行研究。研究结果表明:基于幂指数法的地震模拟振动台频域前馈补偿方法能够快速收敛,迭代次数较少,可以大幅提高振动台的波形复现精度,能够提高振动台的控制性能。 展开更多
关键词 地震模拟振动台 振动台控制 前馈补偿 幂指数方法 迭代学习控制
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10个鲜食葡萄品种在甘肃兰州的品质表现及抗寒性 被引量:1
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作者 王玉安 朱燕芳 郝燕 《经济林研究》 北大核心 2024年第1期266-273,共8页
【目的】筛选适宜甘肃兰州及同类型气候区发展的品质优良、抗寒性好的葡萄新品种。【方法】以10个引进的鲜食葡萄品种‘春光’‘贵妃玫瑰’‘巨玫瑰’‘蜜光’‘晚黑宝’‘无核翠宝’‘浪漫红颜’‘阳光玫瑰’‘晶红宝’和‘SP9715’为... 【目的】筛选适宜甘肃兰州及同类型气候区发展的品质优良、抗寒性好的葡萄新品种。【方法】以10个引进的鲜食葡萄品种‘春光’‘贵妃玫瑰’‘巨玫瑰’‘蜜光’‘晚黑宝’‘无核翠宝’‘浪漫红颜’‘阳光玫瑰’‘晶红宝’和‘SP9715’为研究对象,分析评价盛果期葡萄的单粒质量、单穗质量、香味、可溶性固形物含量、可溶性糖含量、可滴定酸含量、糖酸比、维生素C含量等主要品质指标,测定低温胁迫后各品种1年生休眠枝的相对电导率、可溶性糖含量、可溶性蛋白含量、脯氨酸含量、丙二醛含量,将10个品种枝条在不同低温处理下的相对电导率运用Logistic方程进行拟合,得出各品种的半致死温度。采用主成分分析法对不同品种的果实品质和枝条抗寒力进行综合评价。【结果】随着温度的降低,10个鲜食葡萄品种枝条的相对电导率逐渐升高,可溶性蛋白含量逐渐上升,脯氨酸含量逐渐升高,可溶性糖含量的变化不尽相同,丙二醛含量总体呈现逐渐上升的趋势。在10个品种中:‘阳光玫瑰’的半致死温度最低,为-22.38℃;其次为‘浪漫红颜’和‘春光’,半致死温度分别为-21.96、-20.75℃;‘晚黑宝’的半致死温度最高,为-18.94℃。【结论】在甘肃兰州地区,根据果实品质和抗寒性的综合评价结果由优到劣排序,10个品种依次为‘蜜光’‘阳光玫瑰’‘春光’‘巨玫瑰’‘SP9715’‘贵妃玫瑰’‘晶红宝’‘无核翠宝’‘晚黑宝’‘浪漫红颜’。 展开更多
关键词 鲜食葡萄 品质 抗寒性
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穿断层隧道NPR锚索支护体系抗震特性振动台试验研究 被引量:1
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作者 陶志刚 丰于翔 +3 位作者 赵易 张晓宇 何满潮 雷啸天 《岩土力学》 EI CAS CSCD 北大核心 2024年第4期939-949,共11页
为研究具有负泊松比效应(negative Poisson’s ratio,NPR)的恒阻大变形锚索在地震作用下的吸能特性与动力响应规律,利用振动台开展含断层隧道使用普通锚索支护以及使用NPR锚索支护的振动台物理模型试验,对比分析地震作用下处于不同围岩... 为研究具有负泊松比效应(negative Poisson’s ratio,NPR)的恒阻大变形锚索在地震作用下的吸能特性与动力响应规律,利用振动台开展含断层隧道使用普通锚索支护以及使用NPR锚索支护的振动台物理模型试验,对比分析地震作用下处于不同围岩条件中以及使用不同锚索进行支护时隧道结构的动力响应规律。研究结果表明:在同一地震波作用下,使用NPR锚索进行支护的隧道结构破坏程度与使用普通锚索进行支护的隧道结构相比有明显的改善,表明NPR锚索在地震作用下具有良好的吸能特性,能够为隧道结构提供有效支护;通过对比分析普通锚索与NPR锚索的锚索轴力时程曲线可知,在地震波作用下,普通锚索会发生破断现象,轴力突降至零,而NPR锚索的高恒阻力能够持续提供有效支护;分析隧道结构各测点的加速度、应变、土压力等动力响应可知,隧道断层区域在地震作用下的动力响应更为明显,隧道结构在地震作用下呈现出拱肩→拱腰→拱顶的破坏规律,这一研究成果为类似隧道工程的支护对策提供了理论参考。 展开更多
关键词 振动台试验 隧道支护 NPR锚索 地震响应
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理气舒心片中染色剂金胺O检测方法研究 被引量:1
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作者 马晓静 张强 +2 位作者 李本淳 崔业波 马彧 《亚太传统医药》 2024年第2期32-35,共4页
目的:建立理气舒心片中染色剂金胺O的检测方法。方法:色谱柱为OMNI-C_(18)柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.033 mol·L^(-1)磷酸二氢钾溶液(30∶70),流速为1.0 mL·min^(-1),柱温为30℃,检测波长为436 nm。结果:金... 目的:建立理气舒心片中染色剂金胺O的检测方法。方法:色谱柱为OMNI-C_(18)柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.033 mol·L^(-1)磷酸二氢钾溶液(30∶70),流速为1.0 mL·min^(-1),柱温为30℃,检测波长为436 nm。结果:金胺O在0.967~8.703μg·mL^(-1)范围内与峰面积线性关系良好(r=0.9995),加样回收率为95.01%(RSD=2.3%,n=6),精密度、重复性和溶液稳定性良好,方法检出限为0.092μg·g^(-1)。6家生产企业共38批样品中发现有1家企业的5批样品中检出金胺O,含量在1.06~4.63μg·g^(-1)。结论:该方法操作简便、灵敏度好、准确度高,可用于理气舒心片中金胺O的检测。 展开更多
关键词 理气舒心片 染色剂 金胺O 液相色谱法
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