Modeling of SACK-based Fast Retransmission and Recovery

Zhiming Wang,Xiaoping Zeng,Xiaofan Jia,Xue Liu,Li Chen 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.6

Selective acknowledgment (SACK)-based retransmission and recovery mechanism has been implemented in most of current transmission control protocol (TCP) stacks. A new SACK-based loss recovery algorithm is defined in RFC6675 under standard track. Existing models in literatures on modeling TCP SACK, which usually use SACK-based retransmission and recovery mechanism, is no longer accurate for two reasons: 1) they ignore transmission of new packets before retransmission of the last loss; 2) they are based on the strategy that pipe is decreased by 2 upon receipt of a partial ACK, where pipe is the estimated number of outstanding packets. This paper develops a new method to derive the expected number of new packets transmitted between retransmission of the first loss and the last, proposes a model that estimates the expected number of packets transmitted during fast retransmission and recovery phase (FRR) and the corresponding expected duration based on RFC6675. The numerical results show that the proposed model can accurately estimate the expected number of packets transmitted during FRR and the corresponding expected duration based on RFC6675.

The SnRK2 family in pepper (Capsicum annuum L.): genome-wide identifcation and expression analyses during fruit development and under abiotic stress

Zhiming Wu,Jiaowen Cheng,Fang Hu,Cheng Qin,Xiaowan Xu,Kailin Hu 한국유전학회 2020 Genes & Genomics Vol.42 No.10

Plant-specifc SnRK2 (sucrose nonfermenting-1-related protein kinase 2) genes play crucial roles in the coordination of plant growth and development and responses to stress. However, comprehensive studies have not been performed for this gene family in pepper (Capsicum annuum), a very important Solanaceous vegetable worldwide. To fully understand the status of SnRK2s in chili pepper, a total of 9 putative SnRK2 genes (named CaSnRK2.1-2.9) were identifed in pepper in the present study. These genes were located on 7 diferent chromosomes and classifed into three subfamilies based on the phylogenetic tree. Their conserved motif compositions and exon-intron structures were systematically analyzed, and the results strongly supported the classifcation. Furthermore, a total of 81 putative cis-elements were found in the promoter regions, and the cis-elements related to hormone and stress signaling were abundant. Finally, the CaSnRK2 gene expression profles among diferent tissues, especially developing fruit tissue, and under various abiotic stresses were investigated to identify tissuespecifc or stress-responsive candidates. This study was the frst to comprehensively investigate the SnRK2 family in pepper, and the results provide important clues for further functional analyses of fruit development and abiotic stress responses.

The Deviation Characteristics of High-speed Train Running Time in Section and its Effect on Transport Capacity

Zhiming Yuan,Qi Zhang,Tao Wang,Feng Chen 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.10

Starting from the phenomenon that a large number of trains’ actual arrival & departure time deviate from specified time in train working diagram in the database of high speed railway dispatching system, the paper analyzes the defects of current train running time calculation method. Based on data mining theory, a section running time deviation calculation model for high speed railway train is proposed. Then the properties of train section running time deviation are studied in three different cases (non-stop both at the start and the end of section, stop at the end of section, and departure at the start of section) with the data from a Chinese railway bureau dispatching system, and its further influence on carrying capacity is analyzed. The results show that three deviation cases all fit Gauss distribution and the accumulative deviation time can increase the transport capacity for more than 1 million passengers per year.

Effects of Surface Machining by a Lathe on Microstructure of Near Surface Layer and Corrosion Behavior of SA182 Grade 304 Stainless Steel in Simulated Primary Water

( Zhiming Zhang ),( Jianqiu Wang ),( En-hou Han ),( Wei Ke ) 한국부식방식학회(구 한국부식학회) 2019 Corrosion Science and Technology Vol.18 No.1

To find proper lathe machining parameters for SA182 Grade 304 stainless steel (SS), six kinds of samples with different machining surface states were prepared using a lathe. Surface morphologies and microstructures of near surface deformed layers on different samples were analysed. Surface morphologies and chemical composition of oxide films formed on different samples in simulated primary water with 100 μg/L O₂ at 310 ℃ were characterized. Results showed that surface roughness was mainly affected by lathe feed. Surface machining caused grain refinement at the top layer. A severely deformed layer with different thicknesses formed on all samples. In addition to high defect density caused by surface deformation, phase transformation, residual stress, and strain also affected the oxidation behaviour of SA182 Grade 304 SS in the test solution. Machining parameters used for # 4 (feed, 0.15 mm/r; back engagement, 2 mm; cutting speed, 114.86 m/min) and # 6 (feed,0.20 mm/r; back engagement, 1 mm; cutting speed, 73.01 m/min) samples were found to be proper for lathe machining of SA182 Grade 304 SS.

Shear Behavior of Marlstone Containing Parallel Fissure under Normal Unloading

Zhiming Yin,Xinrong Liu,Zhongping Yang,Yanlei Wang 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.4

Shear tests under normal unloading were carried out to further study the shear mechanical behavior of marlstone containing parallel fissures. The results reveal that the failure on the rock bridge is tensile failure except for the limited extrusion failure at the tip of the prefabricated fissure. The failure on both sides is generally tensile-shear mixed failure, in which the tensile failure is mainly concentrated in the middle of both sides. In general, it can be summarized as a tensile-shear failure mode of STS-T-STS (S means shear failure, T means tension failure). The failure normal stress of the specimens gradually increases and then decreases with the increase of the fissure inclination, increases with an increase in the initial normal/shear stress, and decreases with the increase of the unloading rate. Strong dilation occurred in the shear process of the specimens, which shows obvious arch effect. The variation law of dilatancy deformation and horizontal deformation in the stage of normal stress unloading is just opposite to that of the failure normal stress. The increasing effect of high shear stress on shear deformation is greater than that of dilatancy deformation, while the inhibiting effect of high normal stress on dilatancy deformation is greater than that of the shear deformation.

Condition assessment of stay cables through enhanced time series classification using a deep learning approach

Zhiming Zhang,Jin Yan,Liangding Li,Hong Pan,Chuan-Zhi Dong 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.1

Stay cables play an essential role in cable-stayed bridges. Severe vibrations and/or harsh environment may result in cable failures. Therefore, an efficient structural health monitoring (SHM) solution for cable damage detection is necessary. This study proposes a data-driven method for immediately detecting cable damage from measured cable forces by recognizing pattern transition from the intact condition when damage occurs. In the proposed method, pattern recognition for cable damage detection is realized by time series classification (TSC) using a deep learning (DL) model, namely, the long short term memory fully convolutional network (LSTM-FCN). First, a TSC classifier is trained and validated using the cable forces (or cable force ratios) collected from intact stay cables, setting the segmented data series as input and the cable (or cable pair) ID as class labels. Subsequently, the classifier is tested using the data collected under possible damaged conditions. Finally, the cable or cable pair corresponding to the least classification accuracy is recommended as the most probable damaged cable or cable pair. A case study using measured cable forces from an in-service cable-stayed bridge shows that the cable with damage can be correctly identified using the proposed DL-TSC method. Compared with existing cable damage detection methods in the literature, the DL-TSC method requires minor data preprocessing and feature engineering and thus enables fast and convenient early detection in real applications.

Experimental study on the composite fouling characteristics of calcium carbonate and nanometer magnesia

Zhiming Xu,Jingtao Wang,Zhimin Han,Yu Zhao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.1

In order to study the composite fouling characteristics of crystallization and particulate, the fouling characteristics of calcium carbonate (CaCO 3 ) and nanometer magnesia in the alternating elliptical axis tube were investigated experimentally. The results show that CaCO 3has obvious effect on the inhibition of the formation of particulate fouling. The asymptotic value of fouling resistance of the nanometer magnesia is the highest and the CaCO 3 is the lowest, and the composite fouling is between them. The fouling rate and the asymptotic value of composite fouling resistance decrease with the increase of the CaCO 3 concentration. The time reaches to the asymptotic value of the three experiments are similar. The variation of nanometer magnesia concentration has greater influence than the CaCO 3 concentration on the asymptotic value of composite fouling. The fouling rate and the asymptotic value of composite fouling resistance increase obviously with the increase of the nanometer magnesia concentration.

Using Fuzzy Neural Network to Assess Network Video Quality

Zhiming Shi 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.7

At present people have higher and higher requirements for network video quality, but video quality will be impaired by various factors, so video quality assessment has become more and more important. This paper focuses on the video quality assessment method using different fuzzy neural networks. Firstly, the main factors that impair the video quality are introduced, such as unit time jamming times, average pause time, blur degree and block effect. Secondly, two fuzzy neural network models are used to build the objective assessment method. By adjusting the network structure to optimize the assessment model, the objective assessment value of video quality is obtained. Meanwhile the advantages and disadvantages of the two models are analysed. Lastly, the proposed method is compared with many recent related assessment methods. This paper will give the experimental results and the detail of assessment process.

Characteristics of calcium carbonate fouling on heat transfer surfaces under the action of electric fields

Zhiming Xu,Hongliang Chang,Bingbing Wang,Jingtao Wang,Qi Zhao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.7

The present study examined the effect of electric fields in calcium carbonate (CaCO 3 ) scale formation on a heat transfer surface. The effects of electric fields ranging from 0 V to 4000 V on the fouling properties of CaCO 3 were investigated. Results showed that the optimal electric voltage was approximately 500 V, at which the asymptotic value of fouling resistance and the deposited weight were minimal and corresponded to 52.8 % and 61.3 % reductions, respectively, compared with the results recorded at 0 V. At higher voltages of 3000 V or 4000 V, the asymptotic value of fouling resistance and the weight of fouling deposits increased relative to those obtained at 0 V. The scanning electron microscope images of the fouling deposits obtained at 0 V showed mainly aragonites with sharp and needle-like crystal structures. The structure of CaCO 3 fouling changed from aragonites to spherical vaterites as the applied voltage was increased.

Linguistic Angst and Multiculturalism: The Singaporean Experience

( Zhiming Bao ) 부경대학교 글로벌지역학연구소 2017 Journal of Global and Area Studies(JGA) Vol.1 No.1

Singapore is a multiethnic, multilingual city-state since its founding. Within the multilingual society, the languages have well-defined functions: English is the working language, and Chinese (Mandarin), Malay and Tamil are the mother tongues of the respective ethnic groups. Within the Chinese community, the traditional dialects are Southern Min (Hokkien, Teochew) and Cantonese. After independence, the government chose English as the working language, closed vernacular schools, and promoted Mandarin within the Chinese community. Within a short span of 40 years since independence, the young Singaporeans have virtually abandoned dialects in favor of English and Mandarin. The government`s language policy has created a multilingual, multicultural community. This article traces the history of the language situation in Singapore, and describes the linguistic angst that permeates the community. The linguistic angst is manifested in language choice, language identity, and language confidence, among others. Linguistic angst is perhaps the by-product of multilingualism and multiculturalism.