Ginsenosides are active ingredients in Panax ginseng with immunomodulatory properties from cellular to organismal levels

You, Long,Cha, Seunghwa,Kim, Mi-Yeon,Cho, Jae Youl The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

The immune system is one of the most important parts of the human body and immunomodulation is the major function of the immune system. In response to outside pathogens or high inflammation, the immune system is stimulated or suppressed. Thus, identifying effective and potent immunostimulants or immunosuppressants is critical. Ginsenosides are a type of steroid saponin derived from ginseng. Most are harmless to the body and even have tonic effects. In this review, we mainly focus on the immunostimulatory and immunosuppressive roles of two types ginsenosides: the protopanaxadiol (PPD)-type and protopanaxatriol (PPT)-type. PPT-type ginsenosides include Rg1, Rg2, Rh4, Re and notoginsenoside R1, and PPD-type ginsenosides include Rg3, Rh2, Rb1, Rb2, Rc, Rd, compound K (CK) and PPD, which activate the immune responses. In addition, Rg1 and Rg6 belong to PPT-type ginsenosides and together with Rg3, Rb1, Rd, CK show immunosuppressive properties. Current explorations of ginsenosides in immunological areas are in the preliminary stages. Therefore, this review may provide some novel ideas to researchers who study the immunoregulatory roles of ginsenosides.

GNSS/INS TIGHTLY COUPLED NAVIGATION WITH ROBUST ADAPTIVE EXTENDED KALMAN FILTER

Youlong Wu,Shuai Chen,Tingting Yin 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.6

GNSS/INS integrated navigation system is particularly outstanding in providing reliable navigation information for land vehicle applications. However, GNSS measurements are easily disturbed in harsh operating environments, especially the accuracy of integrated navigation system integrated with inertial navigation system will be affected accordingly. Hence, a robust adaptive extended Kalman filter procedure is crucial to maintain the stability and reliability of the system. In this study, a robust factor based on local test of standardized residual vector was proposed to deal with potential gross errors, and an adaptive factor based on position dilution of precision which reflect the satellite geometry was proposed to adjust covariance matrix. The robust adaptive factor function models are established to adjust the dynamic model and abnormal measurements. The test results show that the standard extended Kalman filter cannot always give an optimal solution due to the influence of GNSS measurements and satellite geometry especially in the complex environment, while the proposed method improves the reliability of the integrated navigation system by adopting robust adaptive factor.

The Effect of Na0.44MnO2 Formation in Na+-Modified Spinel LiMn2O4

Lilong Xiong,Youlong Xu,Weiguo Wu,Pei Lei,Tao Tao,Xin Dong 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4

Na0.44MnO2 impure phase is formed during the synthetic process of Na+-modified spinel LiMn2O4 by solid state reaction which is confirmed by x-ray diffraction analysis. Scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge measurements are carried out to investigate the effect of the formation of Na0.44MnO2 impurity on the morphology and electrochemical properties of the spinel material. The results show that the spinel material with impure phase exhibits improved cyclability compared to that of the pristine LiMn2O4. The improved electrochemical performance is mainly ascribed to the improved crystallinity of the spinel particles, enhanced stability of the spinel structure and good electronic conductivity of the composite.

The Effect of K-Ion on the Electrochemical Performance of Spinel LiMn2O4

Lilong Xiong,Youlong Xu,Xiang Xiao,Jie Wang,Yutao Li 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.1

Spinel LiMn2O4 is regarded as one of the cathode active materials for rechargeablelithium-ion batteries with the most potential. K+-ion modified LiMn2O4 samples aresynthesized by solid-state reaction. The SEM analysis shows that the modifiedsamples exhibit uniform particle size distribution and much better crystallinity. Themodified sample K1 exhibits ionic diffusion coefficient of 1.43 × 10−10 cm−2 s−1 and2.04 × 10−10 cm−2 s−1, which is much higher than that of the un-modified spinelLiMn2O4 sample. The electrochemical measurements show that K+-ion modificationcould effectively reduce the charge transfer resistance, improve the capacityretention and rate capacity of the spinel materials.

Entity Relationship Modeling Approach Based on Micro- Blog Tag

Junjiang Li,Chunlin Li,Youlong Luo,Yahui Zhao,Xijun Mao 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.7

Due to the huge information, short length and noise data, the traditional method has poor effect on micro-blog entity relationship modeling. In this paper, a new micro-blog user interests discovering approach based on tag is presented to improve the entity relationship modeling. First the matrix of user tag built by traditional way may generate the problem of sparse matrix in tag recommendation, so we introduce the information of micro-blog and establish the bipartite graph of User-Tag and Tag-Word respectively, then use them to recommend tag to micro-blog users. Meanwhile interactive relationship between users also show their interests, we establish a graph of tag relation by users’ relationship and propose a method called Tag Rank on the basis of this graph to improve the precision of the model. Finally, we combine the two methods to discover user interests. In the experiment, we use several measurement metrics: F-value, precision and the recall rate. It is proven that the new approach in the paper have a perfect performance.

Neutral point voltage balance and surge voltage reduction for three‑level converters in PMSM starting process based on narrow pulse suppression

Wenshan Li,Xuhui Wen,Jian Zhang,Youlong Wang 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.6

This paper describes a narrow pulse suppression method that is called hybrid modulation strategy for T-type neutral point clamped (TNPC) three-level converters. Conventional VSVPWM does not function well in high-frequency TNPC converters due to the problem of narrow pulses during the permanent magnet synchronous motor (PMSM) starting process. The narrow pulse phenomenon occurs when the ON/OFF state time of the driving pulse is less than the minimum time required by the power devices. The narrow pulse threatens the safe operation of power devices and results in a high surge voltage and electromagnetic interference. In addition, neutral point voltage unbalance is caused by the narrow pulse in motor starting process. The eff ects of the narrow pulse on the surge voltage and the neutral point voltage are both discussed in this paper. The minimum pulse width function is designed to defi ne the relationship between the gate drive signal and the modulation strategy. The switch pattern limited region of the virtual space vector modulation strategy is analyzed by the minimum pulse width function under both low and high modulation indexes. A resistance inductance load and a PMSM drive system test setup based on a TNPC three-level converter are both established to verify the analysis and eff ectiveness of the proposed method.

A Focused Crawler URL Analysis Algorithm based on Semantic Content and Link Clustering in Cloud Environment

Mingming Li,Chunlin Li,Chao Wu,Youlong Luo 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.2

Currently, the efficiency of the existing focused crawlers is not high because of their unsatisfactory precision. In this article, we analyze the URL analysis methods of the existing focused crawlers, and propose a URL analysis algorithm based on the semantic content and link clustering in cloud environment. In this algorithm, the download URLs are clustered with the philosophy of clustering on the basis of VSM to improve the precision of the focused crawler according to the correlation between download URLs and new URLs. The algorithm is evaluated on Heritrix3.10 compared with Best First Search algorithm and Shark Search algorithm. The experiment results demonstrate that the algorithm proposed can collect web pages related to the given topic accurately and effectively.Moreover, the algorithm has a good ability of learning which proves the possibility of this algorithm.

Identifying Opinion Leader in the Internet Forum

Chao Wu,Chunlin Li,Wei Yan,Youlong Luo,Xijun Mao,Shumeng Du,Mingming Li 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.11

Opinion leader is an authority person who has great influence in BBS. Their linguistic behavior has a huge impact on net citizen’s behavior and thought. In this paper, we propose an algorithm called OLRA (Opinion Leader PageRank Algorithm) based on topic-field to identify opinion leaders in the Internet forum. In the algorithm the closeness degree factor and sentiment analyses are taken into consideration. Meanwhile, these two authority values are defined as the weight of links among users. The data is collected from a number of posts on Tianya forum which is a famous forum in China. In the experiment, the algorithm is compared with Interest-based PageRank algorithm, online time Algorithm, and Experience-based Algorithm, the result shows that the OLRA algorithm can identify opinion leaders than others in the Internet forum effectively.