Recommended Study of the Flow of Information based on TF-IDF

Liuqing Li,Rui Zhang 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.8

The methods to resolve Information overload can mainly classify two kinds: Information Retrieval and Information Filtering. Based on the needs of the people, Information Retrieval will search out the related information and technology from the information stored in some way. Information Filtering will choose out user preferred personalized information from the dynamic information flow based on the filtering requests of the people. The paper analyzed micro-blogs users needs and motivation, According to micro-blogs users motivation, effectively, an approach based on tem frequency inverse document frequency (TF-IDF) was proposed. This article constructed personalized recommendation models in on-line social streams based on ties strength, topic relevance and trust dimensions. The experiments on the Sina blogs data showed that the proposed method could reduce the ranks of irrelevant tweets effectively and achieve better performance than several baseline methods based on cosine and hash tags

Digital-Carrier Multi-Band User Codes for Baseband UWB Multiple Access

Yang, Liuqing,Giannakis, Georgios-B. The Korea Institute of Information and Commucation 2003 Journal of communications and networks Vol.5 No.4

The growing interest towards ultra-wideband (UWB) communications stems from its unique features such as baseband operation, ample multipath diversity, and the potential of enhanced user capacity. But since UWB has to overlay existing narrowband systems, multiple access has to be achieved in the presence of narrowband interference (NBI). However, existing baseband spreading codes for UWB multiple access are not flexible in handling NBI. In this paper, we introduce two novel spreading codes that not only enable baseband UWB multiple access, but also facilitate flexible NBI cancellation. We construct our codes using a single carrier or multiple carriers (SC or MC), which can be implemented with standard discrete-cosine transform (DCT) circuits. With our SC/MC codes, NBI can be avoided by simply nulling undesired digital carriers. Being digital, these SC/MC codes give rise to multiband UWB systems, without invoking analog carriers. In addition, our SC/MC codes enable full multipath diversity, and maximum coding gains. Equally attractive is their capability to reduce the number of interfering users, with simple matched filter operations. Comprehensive simulations are also carried out to corroborate our analysis.

Maximization of Zero-Error Probability for Adaptive Channel Equalization

김남용,Kyu-Hwa Jeong,Liuqing Yang 한국통신학회 2010 Journal of communications and networks Vol.12 No.5

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

Designing Optimal Pulse-Shapers for Ultra-Wideband Radios

Luo, Xiliang,Yang , Liuqing,Giannakis, Georgios-B. The Korea Institute of Information and Commucation 2003 Journal of communications and networks Vol.5 No.4

Ultra-wideband (UWB) technology is gaining increasing interest for its potential application to short-range indoor wireless communications. Utilizing ultra-short pulses, UWB baseband transmissions enable rich multipath diversity, and can be demodulated with low complexity receivers. Compliance with the FCC spectral mask, and interference avoidance to, and from, co-existing narrow-band services, calls for judicious design of UWB pulse shapers. This paper introduces pulse shaper designs for UWB radios, which optimally utilize the bandwidth and power allowed by the FCC spectral mask. The resulting baseband UWB systems can be either single-band, or, multi-band. More important, the novel pulse shapers can support dynamic avoidance of narrow-band interference, as well as efficient implementation of fast frequency hopping, without invoking analog carriers.

새로운 정보이론적 최적기준에 의한 블라인드 등화

김남용 ( Namyong Kim ),리우킹양 ( Liuqing Yang ) 한국인터넷정보학회 2009 인터넷정보학회논문지 Vol.10 No.1

인터넷에 관련된 많은 연구들이 멀티포인트 통신에 집중되어 있으며 이 멀티 포인트 통신에 블라인드 등화기술이 주로 사용되어 왔다. 이 논문에서는, 적응 블라인드 등화기를 위해, 두 확률밀도함수의 유클리드 거리를 최소화하는 기준을 소개한다. 파젼 확률밀도로 표현되는 유클리드 거리가 최소화되기 위해, 전송 심볼의 확률밀도함수와 같은 형태를 갖도록 하는 랜덤 심볼을 수신단에서 생성하여 사용한다. 시뮬레이션 결과로부터, 일반적으로 쓰이는 CMA 알고리듬이 열악한 성능을 보이는 채널모델에 대해 제안한 방식은 크게 향상된 성능을 나타냈다. CMA와 비교했을 때, 채널의 고유치분포비에 대해서도 비교적 민감하지 않은 일관된 성능을 보였으며, ITL의 한 영역으로서, 파젼 확률밀도를 사용한 유클리드 거리 최소화 기준이 블라인드 등화에 성공적으로 응용될 수 있음을 보였다. Blind equalization techniques have been used in multipoint communication on which the research on the internet has focused. In this paper, a criterion of minimizing Euclidian Distance between two PDFs for adaptive blind equalizers has been presented. In order for ED expressed with Parzen PDFs to be minimized, we propose to use a set of randomly generated desired symbols at the receiver so that the PDF of the generated symbols matches that of the transmitted symbols. From the simulation results, the proposed method has shown superior error performance even in severe channel environments in which CMA has shown severe performance degradation. This indicates that the proposed algorithm can be considered relatively insensitive to ESR variations compared to CMA. As a field of ITL, ED minimization using Parzen PDFs has shown possibilities of being successfully applied to blind equalization.

블루투스 비콘 통신을 이용한 네트워크 스마트 LED 조명 시스템 및 활용 방안

김성재(Sungjae Kim),김현지(Hyunji Kim),장유경(Liuqing Zhang),구현철(Hyunchul Ku) 대한전자공학회 2016 대한전자공학회 학술대회 Vol.2016 No.6

Mitophagy Improves Ethanol Tolerance in Yeast: Regulation by Mitochondrial Reactive Oxygen Species in Saccharomyces cerevisiae

( Hongjuan Jing ),( Huanhuan Liu ),( Zhang Lu ),( Cui Liuqing ),( Xiaorong Tan ) 한국미생물생명공학회(구 한국산업미생물학회) 2020 Journal of microbiology and biotechnology Vol.30 No.12

Ethanol often accumulates during the process of wine fermentation, and mitophagy has critical role in ethanol output. However, the relationship between mitophagy and ethanol stress is still unclear. In this study, the expression of ATG11 and ATG32 genes exposed to ethanol stress was accessed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The result indicated that ethanol stress induced expression of the ATG11 and ATG32 genes. The colony sizes and the alcohol yield of atg11 and atg32 were also smaller and lower than those of wild type strain under ethanol whereas the mortality of mutants is higher. Furthermore, compared with wild type, the membrane integrity and the mitochondrial membrane potential of atg11 and atg32 exhibited greater damage following ethanol stress. In addition, a greater proportion of mutant cells were arrested at the G1/G0 cell cycle. There was more aggregation of peroxide hydrogen (H₂O₂) and superoxide anion (O₂ ^·-) in mutants. These changes in H2O2 and O2 ·- in yeasts were altered by reductants or inhibitors of scavenging enzyme by means of regulating the expression of ATG11 and ATG32 genes. Inhibitors of the mitochondrial electron transport chain (mtETC) also increased production of H₂O₂ and O₂ ^·- by enhancing expression of the ATG11 and ATG32 genes. Further results showed that activator or inhibitor of autophagy also activated or inhibited mitophagy by altering production of H₂O₂ and O₂ ^·. Therefore, ethanol stress induces mitophagy which improves yeast the tolerance to ethanol and the level of mitophagy during ethanol stress is regulated by ROS derived from mtETC.

Maximization of Zero-Error Probability for Adaptive Channel Equalization

Kim, Nam-Yong,Jeong, Kyu-Hwa,Yang, Liuqing The Korea Institute of Information and Commucation 2010 Journal of communications and networks Vol.12 No.5

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

Application of Three-phase Hollow Fiber LPME using an Ionic Liquid as Supported Phase for Preconcentration of Malachite Green from Water Samples with HPLC Detection

Zou, Yanmin,Zhang, Zhen,Shao, Xiaoling,Chen, Yao,Wu, Xiangyang,Yang, Liuqing,Zhu, Jingjing,Zhang, Dongmei Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

A novel three-phase hollow fiber liquid phase microextraction was developed for the determination of malachite green (MG) in environmental waters, which selected [BMIM][$PF_6$] mixed with 1% trioctylphosphine oxide (TOPO) as supported phase. Several parameters (accepter phase pH, sample pH, supported phase membrane, volume of accepter phase, salinity, extraction time) that could affect extraction performance were investigated. Under the optimal extraction conditions, the established approach showed excellent characters as: high enrichment factor (212), wide linear range ($0.20-100{\mu}gL^{-1}$), low detection limit ($0.01{\mu}gL^{-1}$), good reproducibility (RSD, 8.9%, n=5) and satisfactory recovery (84.0-106.2%). The method was applied to detect MG at Yangtze River and pond waters in Zhenjiang, Jiangsu province, and 4 sites among 15 sampling sites were found MG with the concentration of $1.73-11.06{\mu}gL^{-1}$, which confirmed that the proposed environmentally friendly method was simple and effective for monitoring MG in aquatic system.

Correlation analysis and prognostic value of miR-29a-3p expression and CYP2C19 genotypes in exfoliated cells from tongue coating of patients with gastroesophageal reflux disease

Zhang Aiqing,Liu Wenjuan,Niu Lingyun,Zhu Liping,Yang Liuqing,Li Xueliang 한국유전학회 2023 Genes & Genomics Vol.45 No.5

Background Gastroesophageal reflux disease (GERD) is a highly prevalent and troublesome disease. Several differentially expressed microRNAs (miRNAs) have been found in GERD. Objective This study was to analyze the correlation of miR-29a-3p expression and CYP2C19 genotypes in exfoliated cells from tongue coating of GERD patients and its prognostic value. Methods Tongue coating specimens were collected from 130 GERD patients and 70 healthy volunteers and their clinical baseline information was recorded. miR-29a-3p expression in exfoliated cells from tongue coating was determined via RT-qPCR, and its diagnostic efficiency on GERD was evaluated via receiver operating characteristic curve. CYP2C19 genotypes and their correlation with miR-29a-3p were analyzed via polymerase chain reaction restriction fragment length polymorphism technique. The adverse events of patients were documented via 12-month follow-up. The impact of miR-29a-3p expression on the healing rate of patients was analyzed via Kaplan-Meier method. Qualification of miR-29a-3p as an independent prognostic factor of GERD patients was analyzed via multivariate Cox regression analysis. Results miR-29a-3p was highly-expressed in exfoliated cells from tongue coating of GERD patients. miR-29a-3p expression had high specificity and sensitivity in diagnosing GERD. CYP2C19 genotypes in GERD patients comprised rapid metabolizers, intermedia metabolizers, and poor metabolizers. miR-29a-3p expression showed a correlation with CYP2C19 genotypes. Higher miR-29a-3p expression predicted higher cumulative incidences of adverse outcomes. Highly-expressed miR-29a-3p was an independent prognostic factor for adverse outcomes of GERD patients. Conclusion High expression of miR-29a-3p aided the diagnosis and predicted poor prognosis of GERD patients.