Passive tracking in heavy clutter with sensor location uncertainty

Guo, Yunfei,Tharmarasa, Ratnasingham,Rajan, Sreeraman,Song, Taek Lyul,Kirubarajan, Thia IEEE 2016 IEEE transactions on aerospace and electronic syst Vol.52 No.4

<P>In order to address the problem of passive tracking from multiple asynchronous angle-only sensors with location uncertainty in heavy clutter, a new iterative maximum-likelihood probabilistic data-association algorithm is proposed in this paper. An iterative prediction-update framework is adopted in the algorithm to simultaneously estimate the target state as well as the sensor state. At the prediction stage, a deterministic sampling approach is used to adjust the measurement covariance with sensor location uncertainty. Then a two-step grid-search technique is proposed to optimize the log-likelihood ratio, combined with a gradient-based search method. At the update stage, the operational sensor states are updated with target state estimates and measurements in corresponding validation gates. The updated sensor states are used to establish a more accurate log-likelihood ratio in the next iteration, which leads to better parameter estimation. In addition, the effects of the sensor location uncertainty on the track acceptance test and the posterior Cramer-Rao lower bound are also analyzed. Simulation results show that the proposed method provides a computationally efficient way to improve track initialization performance in heavy clutter with sensor location uncertainty. The proposed work has applications in sonar tracking, geolocation, electronic support measures, and infrared search and tracking systems.</P>

A new fault diagnosis method based on convolutional neural network and compressive sensing

Yunfei Ma,Xisheng Jia,Huajun Bai,Guozeng Liu,Guanglong Wang,Chiming Guo,Shuangchuan Wang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.11

Compressive sensing is an efficient machinery monitoring framework, which just needs to sample and store a small amount of observed signal. However, traditional reconstruction and fault detection methods cost great time and the accuracy is not satisfied. For this problem, a 1D convolutional neural network (CNN) is adopted here for fault diagnosis using the compressed signal. CNN replaces the reconstruction and fault detection processes and greatly improves the performance. Since the main information has been reserved in the compressed signal, the CNN is able to extract features from it automatically. The experiments on compressed gearbox signal demonstrated that CNN not only achieves better accuracy but also costs less time. The influencing factors of CNN have been discussed, and we compared the CNN with other classifiers. Moreover, the CNN model was also tested on bearing dataset from Case Western Reserve University. The proposed model achieves more than 90 % accuracy even for 50 % compressed signal.

Long Noncoding RNA Expression Profiling During the Neuronal Differentiation of Glial Precursor Cells from Rat Dorsal Root Ganglia

Yunfei Dai,Wei Ma,Tong Zhang,Jinwei Yang,Chenghao Zang,Kuangpin Liu,Xianbin Wang,Jiawei Wang,Zhen Wu,Xingkui Zhang,Chunyan Li,Junjun Li,Xiangpeng Wang,Jianhui Guo,Liyan Li 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.3

Long noncoding RNAs (lncRNAs) play important roles in the process of cell fate determination. However, their function and expression profiles have not yet been systematically investigated during the transdifferentiation of glial precursor cells derived from dorsal root ganglia (DRG) in the peripheral nervous system. Our results demonstrated significant differences in gene architecture and expression among the three transcript types (lncRNA, mRNA, and TUCP). Distinct differences in transcript length, exon number, and ORF length were identified between lncRNAs and mRNAs after comparative analysis of their structure and sequence conservation. We found that the upregulated lncRNAs outnumbered the downregulated lncRNAs in glial precursor cells cultured with proBDNF antiserum compared with the levels in glial precursor cells cultured without proBDNF antiserum. By a series of GO and KEGG analyses, we found that the effects of some lncRNAs on their target genes in cis were related to nerve growth factor-induced cell cycle, cell phenotype change, and neuronal differentiation. The qRT-PCR verification results of lncRNAs ENSRNOT00000091991, ENSRNOT00000087717, and LNC_000429 were mostly consistent with the sequencing results. The candidate lncRNAs may be associated with the neuronal transdifferentiation of glial precursor cells. Our study provides the first evidence for a remarkably diverse pattern of lncRNA expression during neuronal differentiation of glial precursor cells from rat DRG, and also provides a resource for lncRNA studies in the field of cell differentiation.

Cdyl2-60aa encoded by CircCDYL2 accelerates cardiomyocyte death by blocking APAF1 ubiquitination in rats

Deng Yunfei,Zeng Xiaochen,Lv Yifei,Qian Zhiyuan,Guo Peijie,Liu Yi,Chen Shaoliang 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The loss of cardiomyocytes (CMs) after myocardial infarction (MI) is widely acknowledged to initiate the development of heart failure (HF). Herein, we found that circCDYL2 (583 nt) derived from chromodomain Y-like 2 (Cdyl2) is significantly upregulated in vitro (oxygen-glucose deprivation (OGD)-treated CMs) and in vivo (failing heart post-MI) and can be translated into a polypeptide termed Cdyl2-60aa (~7 kDa) in the presence of internal ribosomal entry sites (IRES). Downregulation of circCDYL2 significantly decreased the loss of OGD-treated CMs or the infarcted area of the heart post-MI. Additionally, elevated circCDYL2 significantly accelerated CM apoptosis via Cdyl2-60aa. We then discovered that Cdyl2-60aa could stabilize protein apoptotic protease activating factor-1 (APAF1) and promote CM apoptosis; heat shock protein 70 (HSP70) mediated APAF1 degradation in CMs by ubiquitinating APAF1, which Cdyl2-60aa could competitively block. In conclusion, our work substantiated the claim that circCDYL2 could promote CM apoptosis via Cdyl2-60aa, which enhanced APAF1 stability by blocking its ubiquitination by HSP70, suggesting that it is a therapeutic target for HF post-MI in rats.

Effects of sheep slaughter age on myogenic characteristics in skeletal muscle satellite cells

Han Yunfei,Guo Wenrui,Su Rina,Zhang Yanni,Yang Le,Borjigin Gerelt,Duan Yan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.4

Objective: The objective of this study was to investigate the effects of sheep slaughter age on myogenic characteristics in skeletal muscle satellite cells (SMSCs).Methods: Primary SMSCs were isolated from hind leg biceps femoris muscles of Wurank lambs (slaughtered at three months, Mth-3) and adults (slaughtered at fifteen months, Mth-15). SMSCs were selected by morphological observation and fluorescence staining. Myogenic regulatory factors (MRF) and myosin heavy chain (MyHC) expressions of SMSCs were analyzed on days 1, 3, 4, and 5.Results: The expressions of myogenic factor 5 (Myf5), myogenic differentiation (MyoD), Myf6, and myogenin (MyoG) in Mth-15 were significantly higher in Mth-15 than in Mth-3 on days 1, 3, and 4 (p<0.05). However, MyoG expression in Mth-15 was significantly lower than in Mth-3 on day 5 (p<0.05). The expressions of MyHC I, MyHC IIa, and MyHC IIx in Mth-15 were significantly higher than in Mth-3 on days 1 and 3 (p<0.05), and MyHC IIb were significantly lower than in Mth-3 on days 3 and 4 (p<0.05). In contrast, the expression of MyHC IIx in Mth-15 was significantly lower and MyHC IIb was significantly higher than in Mth-3 on days 5 (p<0.05).Conclusion: The slaughter age altered the expression of MRFs and MyHCs in SMSCs while differentiation, which caused the variation of myogenic characteristics, and thus may affect the meat quality of Wurank sheep. Objective: The objective of this study was to investigate the effects of sheep slaughter age on myogenic characteristics in skeletal muscle satellite cells (SMSCs). Methods: Primary SMSCs were isolated from hind leg biceps femoris muscles of Wurank lambs (slaughtered at three months, Mth-3) and adults (slaughtered at fifteen months, Mth-15). SMSCs were selected by morphological observation and fluorescence staining. Myogenic regulatory factors (MRF) and myosin heavy chain (MyHC) expressions of SMSCs were analyzed on days 1, 3, 4, and 5. Results: The expressions of myogenic factor 5 (Myf5), myogenic differentiation (MyoD), Myf6, and myogenin (MyoG) in Mth-15 were significantly higher in Mth-15 than in Mth-3 on days 1, 3, and 4 (p<0.05). However, MyoG expression in Mth-15 was significantly lower than in Mth-3 on day 5 (p<0.05). The expressions of MyHC I, MyHC IIa, and MyHC IIx in Mth-15 were significantly higher than in Mth-3 on days 1 and 3 (p<0.05), and MyHC IIb were significantly lower than in Mth-3 on days 3 and 4 (p<0.05). In contrast, the expression of MyHC IIx in Mth-15 was significantly lower and MyHC IIb was significantly higher than in Mth-3 on days 5 (p<0.05). Conclusion: The slaughter age altered the expression of MRFs and MyHCs in SMSCs while differentiation, which caused the variation of myogenic characteristics, and thus may affect the meat quality of Wurank sheep.

EDGE: An Enticing Deceptive-content GEnerator as Defensive Deception

( Huanruo Li ),( Yunfei Guo ),( Shumin Huo ),( Yuehang Ding ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.5

Cyber deception defense mitigates Advanced Persistent Threats (APTs) with deploying deceptive entities, such as the Honeyfile. The Honeyfile distracts attackers from valuable digital documents and attracts unauthorized access by deliberately exposing fake content. The effectiveness of distraction and trap lies in the enticement of fake content. However, existing studies on the Honeyfile focus less on this perspective. In this work, we seek to improve the enticement of fake text content through enhancing its readability, indistinguishability, and believability. Hence, an enticing deceptive-content generator, EDGE, is presented. The EDGE is constructed with three steps: extracting key concepts with a semantics-aware K-means clustering algorithm, searching for candidate deceptive concepts within the Word2Vec model, and generating deceptive text content under the Integrated Readability Index (IR). Furthermore, the readability and believability performance analyses are undertaken. The experimental results show that EDGE generates indistinguishable deceptive text content without decreasing readability. In all, EDGE proves effective to generate enticing deceptive text content as deception defense against APTs.

CacheSCDefender: VMM-based Comprehensive Framework against Cache-based Side-channel Attacks

( Chao Yang ),( Yunfei Guo ),( Hongchao Hu ),( Wenyan Liu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.12

Cache-based side-channel attacks have achieved more attention along with the development of cloud computing technologies. However, current host-based mitigation methods either provide bad compatibility with current cloud infrastructure, or turn out too application-specific. Besides, they are defending blindly without any knowledge of on-going attacks. In this work, we present CacheSCDefender, a framework that provides a (Virtual Machine Monitor) VMM-based comprehensive defense framework against all levels of cache attacks. In designing CacheSCDefender, we make three key contributions: (1) an attack-aware framework combining our novel dynamic remapping and traditional cache cleansing, which provides a comprehensive defense against all three cases of cache attacks that we identify in this paper; (2) a new defense method called dynamic remapping which is a developed version of random permutation and is able to deal with two cases of cache attacks; (3) formalization and quantification of security improvement and performance overhead of our defense, which can be applicable to other defense methods. We show that CacheSCDefender is practical for deployment in normal virtualized environment, while providing favorable security guarantee for virtual machines.

Study of Proteolysis, Lipolysis, and Volatile Compounds of a Camembert-type Cheese Manufactured Using a Freeze-dried Tibetan Kefir Co-culture during Ripening

Jun Mei,Qizhen Guo,Yan Wu,Yunfei Li,Huaning Yu 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.2

The use of a freeze-dried Tibetan kefir coculture as a starter for production of Camembert-type cheese was investigated. Maturation of produced cheese was monitored for 35 days and the chemical composition, proteolysis, lipolysis, and volatile compounds were studied. The cheese underwent proteolysis. The content of pH 4.6- soluble nitrogen, 12% trichloroacetic acid-soluble nitrogen, and the total free amino acid content increased while the total nitrogen content decreased. Palmitic, myristic, oleic, and capric acid were the representative free fatty acids, which increased in amount during ripening. A total of 45 compounds were detected, including 16 acids, 8 ketones, 6 alcohols, 7 esters, and 8 unclassified compounds. Volatile carboxylic acids were abundant in the headspace of the cheese.

Dynamic reverse proxy chain generation for networks in data centers

Yang Bai,Guixin Guo,Yong Wang,Kangyou Zhong,Jiang Li,Yunfei Du 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

Reverse proxy, as one of the important components required by the data center to provide application services, has functions of access control, load balancing, connecting to different types of networks, etc. In the future, as the application services requiring reverse proxy further increase, network types become more and more diverse and complex, and the network hierarchy becomes higher and higher, reverse proxy will change from a single layer to multiple layers to form a reverse proxy chain. The construction of the reverse proxy chain will become one of the bottlenecks of data center networking operation and maintenance. In this paper, we propose a method of automatically constructing reverse proxy chains to avoid the problem of manual static configuration of the reverse proxy chain which is time-consuming, laborious, and difficult to maintain. In our software-defined networking experiment, we simulated a full-binary-tree-like topology of 1534 nodes. We recorded the time to generate and remove proxy chains of various lengths. The average time to generate all reverse proxy chains in the topology consisting of 1534 nodes with 100ms delay is around 5100ms, much smaller than manual configuration, which usually needs several hours.

Evaluation of Freeze-dried Tibetan Kefir co-culture as a Starter for Production of Bod ljong Cheese

Jun Mei,Fei Feng,Qizhen Guo,Yunfei Li,Yan Wu 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.3

The physico-chemical profile, proteolysis, flavor, and microbiological changes were investigated, and a sensory evaluation was performed for Bod ljong cheese prepared using a freeze-dried Tibetan kefir co-culture during ripening. The proteolysis level was high, the pH 4.6-soluble nitrogen, 12% trichloroacetic acid-soluble nitrogen, water soluble nitrogen, and total free amino acid contents increased, and the protein content decreased during ripening. The effect of the starter culture on production of aroma-related compounds responsible for cheese flavor was also studied using solidphase microextraction GC-MS techniques. Alcohols and esters were the most abundant volatile compounds. Microbial counts during ripening increased steadily. Lactic acid bacteria, Lactobacillus and Lactococcus, were the dominant flora during ripening. Enterococci, Enterobacteriaceae, and Salmonella sp. bacterial counts were low or zero. The cheese was subjected to sensory evaluation by a panel and compared to commercial Bod ljong-type cheese.