Hang He^1,*, Zhenhan Zhao¹, Weiwei Luo¹, Jinghui Zhang²

Computer Systems Science and Engineering, Vol.39, No.2, pp. 251-264, 2021, DOI:10.32604/csse.2021.017296

Abstract With the increasing number of airports and the expansion of their scale, the aviation network has become complex and hierarchical. In order to investigate the complex network characteristics of aviation networks, this paper constructs a Chinese aviation network model and carries out related research based on complex network theory and K-means algorithm. Initially, the P-space model is employed to construct the Chinese aviation network model. Then, complex network indicators such as degree, clustering coefficient, average path length, betweenness and coreness are selected to investigate the complex characteristics and hierarchical features of aviation networks and explore their causes. Secondly, using K-means… More >

Jingcheng Qian¹, Mingfang Zhu¹, Yingnan Zhao^2,*, Xiangjian He³

Computer Systems Science and Engineering, Vol.39, No.2, pp. 197-209, 2021, DOI:10.32604/csse.2021.016911

Abstract Wind speed prediction is of great importance because it affects the efficiency and stability of power systems with a high proportion of wind power. Temporal-spatial wind speed features contain rich information; however, their use to predict wind speed remains one of the most challenging and less studied areas. This paper investigates the problem of predicting wind speeds for multiple sites using temporal and spatial features and proposes a novel two-layer attention-based long short-term memory (LSTM), termed 2Attn-LSTM, a unified framework of encoder and decoder mechanisms to handle temporal-spatial wind speed data. To eliminate the unevenness of the original wind speed,… More >

Yu Xue^1,2,*, Jiafeng Qin¹, Shoubao Su², Adam Slowik³

Computer Systems Science and Engineering, Vol.39, No.2, pp. 211-219, 2021, DOI:10.32604/csse.2021.016693

Abstract Recently, online learning platforms have proven to help people gain knowledge more conveniently. Since the outbreak of COVID-19 in 2020, online learning has become a mainstream mode, as many schools have adopted its format. The platforms are able to capture substantial data relating to the students’ learning activities, which could be analyzed to determine relationships between learning behaviors and study habits. As such, an intelligent analysis method is needed to process efficiently this high volume of information. Clustering is an effect data mining method which discover data distribution and hidden characteristic from uncharacterized online learning data. This study proposes a… More >

Huma Hayat Khan^1,*, Muhammad Noman Malik², Youseef Alotaibi³, Abdulmajeed Alsufyani⁴, Saleh Alghamdi⁵

Computer Systems Science and Engineering, Vol.39, No.2, pp. 221-236, 2021, DOI:10.32604/csse.2021.016510

Abstract Software crowdsourcing (SW CS) is an evolving software development paradigm, in which crowds of people are asked to solve various problems through an open call (with the encouragement of prizes for the top solutions). Because of its dynamic nature, SW CS has been progressively accepted and adopted in the software industry. However, issues pertinent to the understanding of requirements among crowds of people and requirements engineers are yet to be clarified and explained. If the requirements are not clear to the development team, it has a significant effect on the quality of the software product. This study aims to identify… More >

Xiaokan Wang^1,2,*, Qiong Wang¹, Liang Shuang³, Chao Chen⁴

Computer Systems Science and Engineering, Vol.39, No.2, pp. 237-250, 2021, DOI:10.32604/csse.2021.015945

Abstract Electric vehicles such as trains must match their electric power supply and demand, such as by using a composite energy storage system composed of lithium batteries and supercapacitors. In this paper, a predictive control strategy based on a Markov model is proposed for a composite energy storage system in an urban rail train. The model predicts the state of the train and a dynamic programming algorithm is employed to solve the optimization problem in a forecast time domain. Real-time online control of power allocation in the composite energy storage system can be achieved. Using standard train operating conditions for simulation,… More >

Xuan Sun^1,2,3, Pengyu Liu^1,2,3,*, Xiaowei Jia⁴, Kebin Jia^1,2,3, Shanji Chen⁵, Yueying Wu^1,2,3

Computer Systems Science and Engineering, Vol.39, No.2, pp. 275-286, 2021, DOI:10.32604/csse.2021.015255

Abstract This paper presents an effective machine learning-based depth selection algorithm for CTU (Coding Tree Unit) in HEVC (High Efficiency Video Coding). Existing machine learning methods are limited in their ability in handling the initial depth decision of CU (Coding Unit) and selecting the proper set of input features for the depth selection model. In this paper, we first propose a new classification approach for the initial division depth prediction. In particular, we study the correlation of the texture complexity, QPs (quantization parameters) and the depth decision of the CUs to forecast the original partition depth of the current CUs. Secondly,… More >

Yong Wang, Yongyan Wang^*, Songmei Li, Nan Qin, Peng Du, Tongtong Zhou

Computer Systems Science and Engineering, Vol.39, No.2, pp. 179-195, 2021, DOI:10.32604/csse.2021.014469

Abstract The antiknock capability and thermal protection performance of rescue capsules mainly depend on the structural design of the cabin. By designing a new type of cabin structure, it can resist the impact of explosion shock waves and thermal shocks. In this paper, a new honeycomb-like cabin is proposed; the model has a novel thermal insulation layer design. Then, the antiknock capabilities and thermal protection analysis are carried out by using computer software. The “Autodyn” analysis module in ANSYS Workbench 17.0 has been used to simulate the explosion of TNT with a certain quality in a single room. The pressure map… More >

Ahmed J. Hamad^*, Fawziea M. Hussien, Johain J. Faraj

Energy Engineering, Vol.118, No.5, pp. 1483-1497, 2021, DOI:10.32604/EE.2021.016867

Abstract The fluctuation in drying temperature influences the food products’ quality and drying time significantly during the drying process using an indirect solar dryer. One of the effective methods to reduce these variations in the temperature is based on thermal storage materials to control the drying temperature. An experimental investigation is presented in this study to evaluate the performance of an indirect solar dryer with air double pass using multiple phase change materials (PCM) as thermal storage materials. Two PCMs with different melting points are used to store the available heat energy during peak sunshine periods and reduce the drying temperature… More >

Vibhushit Gupta¹, Shubham K. Verma², Sanjeev Anand², Navin Gupta³, Yatheshth Anand^1,*

Energy Engineering, Vol.118, No.5, pp. 1317-1331, 2021, DOI:10.32604/EE.2021.016732

Abstract The utilization of energy in building sectors comprises 30–40% of the entire global energy consumption. Most of the energy is being utilized for cooling & heating the buildings. These cooling and heating depend on the nature of climate for different places. In this, the detailed analysis of the building envelope across five areas (viz. Srinagar, Jaisalmer, New Delhi, Thiruvananthapuram and Bangalore) representing different climatic zones had been carried out. Simulations are performed for these locations using eQUEST and ANSYS software. Three of the result output from the eQUEST simulation are used to assess the different cases. These outputs are: total… More >

Nugroho Agung Pambudi^1,*, Santiko Wibowo¹, Ranto¹, Lip Huat Saw²

Energy Engineering, Vol.118, No.5, pp. 1565-1576, 2021, DOI:10.32604/EE.2021.016642

Abstract Organic Rankine Cycle (ORC) is one of the solutions to utilize a low temperature geothermal fluid for power generation. The ORC system can be placed at the exit of the separator to extract energy from brine. Furthermore, one of the main components of the system and very important is the pump. Therefore, in this research, the pump rotation is examined to investigate the effect on power output and energy efficiency for low temperature geothermal fluid. The rotation is determined by using an inverter with the following frequencies: 7.5, 10, 12.5, 15 and 17.5 Hz, respectively. R-134 working fluid is employed… More >