The Experts below are selected from a list of 575883 Experts worldwide ranked by ideXlab platform

Kazuo Yamamoto - One of the best experts on this subject based on the ideXlab platform.

  • an on site prototype two stage anaerobic digester for co digestion of food waste and sewage sludge for biogas production from high rise Building
    International Biodeterioration & Biodegradation, 2015
    Co-Authors: Chavalit Ratanatamskul, O Wattanayommanaporn, Kazuo Yamamoto
    Abstract:

    Abstract Up to now, there has been less results from on-site pilot-scale anaerobic co-digestion system, especially for High-Rise Building application. The objective of this study was to develop an on-site prototype two-stage anaerobic digester for co-digestion of food waste and sewage sludge from High-Rise Building for biogas production. The optimal mixing ratio of food waste to sewage sludge, obtained from laboratory-scale, was found to be 7:1. Then, the prototype two-stage anaerobic digester was further designed and constructed. The results showed that COD and total volatile solid (TVS) reduction could be achieved up to 89 and 74%, respectively with the applied hydraulic retention time (HRT) of 24 days. The methane content of biogas was 64 percent. Up to now, the biogas from on-site production has been utilized for cooking at Chulalongkorn University as a model case study for High-Rise Building application.

  • a prototype single stage anaerobic digester for co digestion of food waste and sewage sludge from high rise Building for on site biogas production
    International Biodeterioration & Biodegradation, 2014
    Co-Authors: Chavalit Ratanatamskul, G Onnum, Kazuo Yamamoto
    Abstract:

    Abstract At present, there has been less results from pilot-scale experiments on anaerobic co-digestion system, especially as an on-site system for High-Rise Building application. The objective of this study was to develop a prototype single-stage anaerobic digester for the co-digestion of food waste (FW) and sewage sludge (SWS) from High-Rise Building for on-site biogas production. Here, the prototype system was operated at different hydraulic retention times (HRTs) of 27, 22 and 19 days, corresponding to organic loading rates of 7.9, 10.8 and 14.0 kgCOD/m 3 d. The feed mixed waste ratio (FW/SWS) of 10:1 by weight was selected from the previous laboratory-scale experiment. The results of this study indicate that higher gas production rate was obtained at shorter hydraulic retention time (HRT) of 19 days; however, higher methane content of the biogas was obtained at longer HRT of 27 days. Therefore, enhancement of methane production from the co-digestion could be achieved with sufficient operating HRT. Moreover, the proposed prototype system could reduce total volatile solid up to 70 percent at HRT of 27 days. Up to now, the biogas from on-site production has been utilized for cooking at Chulalongkorn University as a model case study for High-Rise Building application.

Hojjat Adeli - One of the best experts on this subject based on the ideXlab platform.

  • many objective control optimization of high rise Building structures using replicator dynamics and neural dynamics model
    Structural and Multidisciplinary Optimization, 2017
    Co-Authors: Mariantonieta Gutierrez Soto, Hojjat Adeli
    Abstract:

    Recently the authors presented a single-agent Centralized Replicator Controller (CRC) and a decentralized Multi-Agent Replicator Controller (MARC) for vibration control of High-Rise Building structures. It was shown that the use of agents and a decentralized approach enhances the vibration control system. Two key parameters in the proposed control methodologies using replicator dynamics are the total population (total available resources or the sum of actuators forces) and the growth rate. In the previous research, a sensitivity analysis was performed to determine the appropriate values for the population size and growth rate. In this paper, the aforementioned control methodologies are integrated with a multi-objective optimization algorithm in order to find Pareto optimal values for growth rates with the goal of achieving maximum structural performance with minimum energy consumption. A modified neural dynamic model of Adeli and Park is used in this research to solve the many-objective optimization problem where the Normal Boundary Intersection method is employed to find Pareto optimality. Sample results are presented using a 20-story steel benchmark structure subjected to historical and artificial accelerograms.

  • a novel machine learning based algorithm to detect damage in high rise Building structures
    Structural Design of Tall and Special Buildings, 2017
    Co-Authors: Mohammad Hossein Rafiei, Hojjat Adeli
    Abstract:

    Summary A novel model is presented for global health monitoring of large structures such as High-Rise Building structures through adroit integration of 2 signal processing techniques, synchrosqueezed wavelet transform and fast Fourier transform, an unsupervised machine learning technique, the restricted Boltzmann machine, and a recently developed supervised classification algorithm called neural dynamics classification (NDC) algorithm. The model extracts hidden features in the frequency domain of the denoised measured response signals recorded by sensors on different elevations or floors of a structure. The extracted features are used as an input of the NDC to detect and classify the global health of the structure into categories such as healthy, light damage, moderate damage, severe damage, and near collapse. The proposed model is validated using the data obtained from a 3D 1:20 scaled 38-story reinforced concrete Building structure. The results are compared with 3 other supervised classification algorithms: k-nearest neighbor (KNN), probabilistic neural networks (PNN), and enhanced PNN (EPNN). NDC, EPNN, PNN, and KNN yield maximum average accuracies of 96%, 94%, 92%, and 82%, respectively.

  • new method for modal identification of super high rise Building structures using discretized synchrosqueezed wavelet and hilbert transforms
    Structural Design of Tall and Special Buildings, 2017
    Co-Authors: Hyo Seon Park, Hojjat Adeli
    Abstract:

    Summary Measured signals obtained by sensors during dynamic events such as earthquake, wind, and wave contain nonlinear, nonstationary, and noisy properties. In this paper, a new approach is presented for modal parameter identification of structures particularly suitable for very large real-life structures such as super High-Rise Building structures based on the integration of discretized synchrosqueezed wavelet transform, the Hilbert transform, and the linear least-square fit. Its effectiveness is demonstrated first by application to a two-dimensional frames from the literature, and then to the 123-story Lotte World Tower (LWT) under construction in Seoul, Korea. The LWT measurements are very low-amplitude ambient vibrations. Extracting the natural frequencies and damping ratios from such low-amplitude signals are known to be very challenging. Further, the new methodology was compared with the empirical mode decomposition. It is demonstrated that the new method is capable of extracting both natural frequencies and damping rations from low-amplitude signals effectively and with a higher accuracy compared with the empirical mode decomposition approach. The results of this research indicate a super High-Rise Building like LWT has a damping ratio in the range 0.7–3.4%. The new method is quite promising for practical implementations of health monitoring of large real-life structures.

  • comparative study of optimum designs of steel high rise Building structures using allowable stress design and load and resistance factor design codes
    Practice Periodical on Structural Design and Construction, 2005
    Co-Authors: Kamal C Sarma, Hojjat Adeli
    Abstract:

    The writers recently created a fuzzy discrete multicriteria optimization model for automated design of large steel structures subjected to the actual constraints of commonly used design codes. In this work, the model is used to perform a comparative study of optimum designs of steel high rise Building structures using AISC allowable stress design and load and resistance factor design (LRFD) codes. Results are presented for two large structures, a 36-story space moment-resisting frame with cross bracings and a 144-story super High-Rise Building structure with over 20,000 members. LRFD code results in the cost savings in the range of 3.0-6.9% for the 36-story steel structure and 1.7-4.3% for the 144-story steel structure. When serviceability (stiffness) is more of a controlling factor, the LRFD code in general yields a much smaller advantage for weight savings.

Quanyi Huang - One of the best experts on this subject based on the ideXlab platform.

  • investigation on an integrated evacuation route planning method based on real time data acquisition for high rise Building fire
    IEEE Transactions on Intelligent Transportation Systems, 2013
    Co-Authors: Zhuyang Han, Wenguo Weng, Quanlai Zhao, Quanyi Liu, Quanyi Huang
    Abstract:

    Evacuation of occupants in High-Rise Buildings is one of the most important tasks when the Building is subjected to a significant level of fire threat. Since the mechanism of fire spread is too complicated for the trapped people to determine the evacuation route, a real-time evacuation route planning method is needed for rescue and safety management. In this paper, an integrated real-time evacuation route planning method for High-Rise Building fires is proposed. This method is composed of real-time data acquisition, risk distribution calculation, and evacuation route formulation. The real-time data acquisition process is achieved by using the sensor system and the wireless data transmission system, the calculation of risk distribution is based on the risk assessment of casualties, and the formulation of evacuation route is based on the fast marching level set method. To demonstrate the presented method, a sample Building under an assumed fire is used for numerical investigation, and a real Building model is used for experimental investigation. The results show that this method can evaluate the fire status and formulate evacuation strategies instantly in High-Rise Building fire. The risk distribution and the evacuation route of the Building fire can be intuitively displayed. This method can be used in practical applications and will be an important technical basis for the program development of rescue and evacuation.

Partha P Sarkar - One of the best experts on this subject based on the ideXlab platform.

  • an experimental study of a high rise Building model in tornado like winds
    Journal of Fluids and Structures, 2011
    Co-Authors: Zifeng Yang, Partha P Sarkar
    Abstract:

    Abstract An experimental study was conducted to quantify the characteristics of wake vortex and flow structures around a High-Rise Building model as well as the resultant wind loads (both forces and moments) acting on the test model in tornado-like winds. In addition to measuring wind loads acting on the tested High-Rise Building model using a high-sensitivity load cell, a digital Particle Image Velocimetry (PIV) system was used to conduct detailed flow field measurements to quantify the evolution of the unsteady vortex and turbulent flow structures around the test model in tornado-like winds. The measurement results revealed clearly that the evolution of the wake vortex and turbulent flow structures around the test model as well as the resultant wind loads induced by tornado-like winds were significantly different from those in conventional straight-line winds. The detailed flow field measurements were correlated with the wind load measurement data to elucidate the underlying physics to gain further insight into the flow–structure interactions between the tested High-Rise Building model and tornado-like vortex. The new findings derived from the present study could be used to provide more accurate prediction of wind damage potential to built environment with the ultimate goal of reducing life loss, injury casualty, and economic loss that results from tornados.

Zhendong Cui - One of the best experts on this subject based on the ideXlab platform.

  • analysis of electron microscope images of soil pore structure for the study of land subsidence in centrifuge model tests of high rise Building groups
    Engineering Geology, 2013
    Co-Authors: Zhendong Cui, Yajie Jia
    Abstract:

    Abstract The scanning electron microscopy (SEM) images of soil pore structures were quantitatively analyzed for the study of land subsidence in the centrifuge model tests of High-Rise Building groups in this paper. The changes of the macrostructure and microstructure characteristics of the soils before and after centrifuge model test were studied, including the void ratio, the equivalent diameter, the circularity, the shape factor, the distribution of the orientation angle and the morphological fractal dimension of pores. The results demonstrated that the real filling rate can be estimated by 115% of the filling rate calculated by the Otsu method or be estimated by the normalized threshold of the SEM images between [0.34, 0.36]. Variations of the calculated filling rate with the adopted threshold showed the Gaussian function relationship. After the consolidation, 28.0% and 29.6% of the total pore area of the silty clay of layer No. 4 and the clayey soil of layer No. 8 were reduced, respectively, which illustrated the great compressibility and showed good agreement with the large macroscopic subsidence. The pores with radii more than 1 μm occupied the vast majority of the total pore area. The fractal dimension of the pore shapes decreased after the consolidation. Considering the changes of the average eccentricity and the average shape factor, during the soil consolidation, the pores were not simply flattened but parts of the boundaries of pores were compressed to be closed, which made the shape of pores more regular.

  • land subsidence and pore structure of soils caused by the high rise Building group through centrifuge model test
    Engineering Geology, 2010
    Co-Authors: Zhendong Cui, Yiqun Tang
    Abstract:

    Abstract In the urban area of Shanghai, the dewatering of groundwater was controlled strictly and the engineering–environment effect of the High-Rise Building group became to be the main cause of land subsidence in Shanghai. Based on the High-Rise Building group in the soft soil area in Shanghai, the mechanism of land subsidence was studied in this paper by the centrifuge model test. The central area of the Building group has larger subsidence and the subsidence superimposition effect is obvious. It can exceed the allowance and cause land subsidence hazard. The land subsidence affected by the different Building distances was also studied. For smaller Building distances, the subsidence superimposition effect is more obvious. The engineering characteristics of soils are controlled by the state of pore structure of soils to a great extent. The parameter of specific subsidence was put forward as a tie to analyze the relationship between land subsidence and pore structure of soils. The pore structure of each soil layer was studied by the mercury intrusion porosimetry test (MIP) and the pore distribution of each soil layer was studied by the fractal theory. There are mainly macropores in silty clay of layer no. 4, clayey soil of layer no. 8, silty sand of layer no. 7 and layer no. 9 in Shanghai. The ink-bottle effect exists in the intrusion stage in the MIP test. There are four different fractal dimensions in silty clay of layer no. 4 and clayey soil of layer no. 8 and three different fractal dimensions in silty sand of layer no. 7 and layer no. 9.

  • centrifuge modeling of land subsidence caused by the high rise Building group in the soft soil area
    Environmental Earth Sciences, 2010
    Co-Authors: Zhendong Cui, Yiqun Tang, Xuexin Yan
    Abstract:

    With the increase of the High-Rise Buildings, land subsidence induced by human activities becomes a major problem. Land subsidence occurs slowly, but the accumulation results in the cracks in the road, the damage to the pipelines and in the tilting or the cracking of the Buildings. With the withdrawal of groundwater controlled reasonably, the engineering-environmental effect of the dense High-Rise Building group comes to be the main cause of land subsidence. Based on the High-Rise Building group in the soft soil area in Shanghai, the mechanism of land subsidence is studied in this paper by the centrifuge model tests. The central area of the Building group has larger subsidence and the subsidence superimposition effect is obvious. It can exceed the allowance and cause land subsidence hazard. The land subsidence affected by the different Building distances is also studied. For smaller Building distances, the subsidence superimposition effect is more obvious. The larger excess pore water pressure in the pile-base supporting layer of the central area shows that the stress superimposition effect is larger. The earth pressure under the Buildings fluctuates by the disturbance of the pile tips.

  • model test study of land subsidence caused by high rise Building group in shanghai
    Bulletin of Engineering Geology and the Environment, 2008
    Co-Authors: Yiqun Tang, Zhendong Cui, Jianxiu Wang, Xuexin Yan
    Abstract:

    The paper discusses the influence of a group of High-Rise Buildings on land subsidence, based on a modeling exercise. The model consisted of five layers of soils typical of the Shanghai area, with the Buildings placed on piles set in the upper silty sand horizon. It was loaded to represent the construction sequence of the four Buildings. The main settlement was observed to be in the underlying clayey layer. The model demonstrated the increase in pore water pressure with staged loading, its effect on deformation and the increase in effective stress over time. It indicated the largest amount of settlement over time occurs between the Buildings.