Research Status and Trend Analysis on Context-Aware Application (2005-2014)

Liyi Zhang,Cong Yin 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.10

Recently, context-aware application has been one of the hottest researching fields in the domain of business intelligence. By reviewing the progress of context-aware application in these years, this paper proposes a four-layer classification framework and gives an analysis and comparison to the concept and theory, context-aware computing and typical application which are related to context-aware application. It also summarizes their characteristics and effects from the point of practical use. Lastly, some discussions and suggestions were given to emphasize the difficulty of current application conditions.

Study of Copyright Protection for Merchandise Pictures in E-Commerce

Liyi Zhang,Chang Liu 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.7

For solving the picture misappropriation problem in e-commerce, this paper proposes a content-based copyright detection method. In the method, a picture is smoothed by bilateral filter to ensure the integrity of its key points, and the shape feature and texture feature are extracted by Hu moment and Gabor filter respectively. Finally copyright-infringing pictures are detected by calculating the Euclidean distance and we use fuzzy heuristics to measure similarity between the query and the database images. The test dataset is crawled from the largest e-commerce website (Taobao.com). The copyright-infringing pictures can be detected by the method and the average accuracy reaches 91%, achieved the desired effect.

Analytical Calculation of the 3D Magnetic Field Created by Non-Periodic Permanent Magnet Arrays

Zhang, He,Kou, Baoquan,Li, Liyi Journal of International Conference on Electrical 2012 Journal of international Conference on Electrical Vol.1 No.3

In this paper, the three-dimensional magnetic field created by non-periodic magnet arrays is calculated analytically. The analytical expression of the magnetic field is derived by using a magnetic charge model. The influence of ferromagnetic boundaries is formulated with an image method. Finally, we compare the results determined by analytical calculations to those from a finite element simulation.

Does Early Endoscopy Affect the Clinical Outcomes of Patients with Acute Nonvariceal Upper Gastrointestinal Bleeding? A Systematic Review and Meta-Analysis

Bai Liyi,Jiang Wei,Cheng Rui,Dang Yan,Min Li,Zhang Shutian 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.4

Background/Aims: In patients with acute nonvariceal upper gastrointestinal bleeding (ANVUGIB), the optimal timing of endoscopy is still a matter of dispute. We conducted a systematic review and meta-analysis to determine the clinical benefit of early endoscopy. Methods: A literature search of the MEDLINE, Embase, and Cochrane databases was conducted to identify publications from inception to March 1, 2022. Eligible studies included observational cohort studies and randomized controlled trials that reported clinical outcomes of endoscopy in patients with ANVUGIB. ANVUGIB patients who underwent endoscopy within 24 hours of admission were considered to have had an early endoscopy. The primary outcome was the mortality rate in ANVUGIB patients who had early or nonearly endoscopy. Results: The final analysis included five randomized controlled studies (RCTs) and 20 observational studies from the 1,206 identified articles. The mortality rate was not significantly reduced among patients who received endoscopy performed within 24 hours, whether in cohort studies nor in RCTs. For subgroup analysis, a higher mortality rate was found only among patients who received very early endoscopy within 12 hours (odds ratio, 1.66; p<0.001, I2=0) in cohort studies. No significant difference in mortality rates was found among patients at high risk of bleeding who received early versus nonearly endoscopy. Conclusions: Early endoscopy within 24 hours does not appear to significantly reduce the mortality rates of patients with ANVUGIB. Further well-designed studies are warranted to address if very early endoscopy within 12 hours can provide a clinical benefit for patients at high risk of bleeding.

Phase, Structure, and Dynamics of the Hydration Layer Probed by Atomic Force Microscopy

Bai, Liyi,Zhang, Zhengqing,Jang, Joonkyung American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol.123 No.35

<P>Using the molecular dynamics method we simulate the hydration layer probed by an atomic force microscope (AFM) tip. We investigate how the AFM tip affects the phase, structure, and dynamics of the intrinsic hydration layer formed on a hydrophobic carbon plate. Without the AFM tip the molecular packing and orientation of the hydration layer are ordered up to the second molecular layer. With approaching the tip, the hydration layer is perturbed and eventually evaporates. The force-distance curve in AFM lacks an oscillation typically found for the hydration layer formed on a hydrophilic surface. The molecular diffusions parallel and perpendicular to the plate are, respectively, enhanced and restricted by the tip. The molecular reorientation is significantly slowed down by the tip and plate, which disrupt the hydrogen-bond network present in the bulk water.</P> [FIG OMISSION]</BR>

Dewetting transition of water confined between atomically rough surfaces: A lattice gas Monte Carlo simulation study

Bai, Liyi,Jang, Jihye,Zhang, Zhengqing,Jang, Joonkyung Elsevier 2018 Chemical physics letters Vol.694 No.-

<P><B>Abstract</B></P> <P>Using lattice gas Monte Carlo simulations, we studied the dewetting transition of water confined between a spherical tip and a plate, which is relevant to atomic force microscopy measurements conducted in water. The dewetting transition was investigated by varying the tip-plate distance, tip size, and the pressure of water. With introduction of an atomic scale roughness (1 < nm) in the tip and the plate, the dewetting transition significantly increased in range and yielded an enhanced hydrophobic force between the tip and the plate. This finding is in agreement with the experimental results previously reported by Singh et al.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Water confined between a spherical tip and a plate was theoretically studied. </LI> <LI> Lattice gas Monte Carlo simulation on the dewetting transition of confined water. </LI> <LI> Atomic scale roughness significantly affects the dewetting transition. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Parameter identification of energy consumption dynamic model for double‑motor‑driven belt conveyers based on Actor–Critic framework

Li Xiao,Liyi Zhang,Feng Gao,Zhi Yan,Yanqin Li,Wenqiang Song 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.3

Research on the energy consumption model of belt conveyors is of great significance when it comes to reducing energy consumption. When compared with a conveyor driven by a single DC motor, the energy consumption model of a conveyor driven by dual motors and its parameter identifications are more complicated. Thus, a data-driven method called Actor–Critic is integrated into the analytical expression method to build an energy consumption model and to estimate the parameters for belt conveyors driven by dual motors. In accordance with the measured current, speed, and capacity, three significant components in the Actor–Critic method, namely action, observation, and reward, are, respectively, designed to estimate parameters without model error disturbance or state operation. Results from experimental studies demonstrate the accuracy and robustness of the proposed method.

Research on Ant Colony Algorithm Optimization Neural Network Weights Blind Equalization Algorithm

Yanxiang Geng,Liyi Zhang,Yunshan Sun,Yao Zhang,Nan Yang,Jiawei Wu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

The project of ant colony algorithm optimization neural network combining blind equalization algorithm is proposed. The better initial weights of neural networks are provided because of the randomness, ergodicity and positive feedback of the ant colony algorithm. And then, a combination of optimal weights are found through BP algorithm, which is fast local search speed. Thus blind equalization performance is improved. Computer simulation show that, the novel blind equalization algorithm speeds up the convergence rate, reduces the remaining steady-state error and bit error rate, which is compared with the Neural Network Blind Equalization Algorithm(NNBE) and Genetic Algorithm optimization Neural Network Blind Equalization Algorithm(GA-NNBE) .

Capacitive deionization of saline water using sandwich-like nitrogen-doped graphene composites <i>via</i> a self-assembling strategy

Yan, Tingting,Liu, Juan,Lei, Hong,Shi, Liyi,An, Zhongxun,Park, Ho Seok,Zhang, Dengsong The Royal Society of Chemistry 2018 Environmental science Vol.5 No.11

<P>Capacitive deionization (CDI) is a promising water treatment technology that is proposed to solve water scarcity. In this study, sandwich-like nitrogen-doped graphene composites were designed and produced as high-performance CDI electrodes <I>via</I> a self-assembling strategy. Nitrogen-doped mesoporous carbon was directly created and assembled onto the graphene surface using dopamine hydrochloride as a carbon and nitrogen source and nano-silica as a hard template. This unique sandwich architecture provides a large accessible surface area and lower electronic resistivity, resulting from creating a “plane-to-porous plane” conducting network for increased adsorption sites and rapid electron transportation pathways. The specific surface area (918 m<SUP>2</SUP> g<SUP>−1</SUP>) and excellent wettability of sandwich-like nitrogen-doped graphene were further improved by incorporating nitrogen in surface texture and chemistry. The material was tested for the CDI application in NaCl aqueous solution. The sandwich-like nitrogen-doped graphene electrodes demonstrated a high salt adsorption capacity of up to 18.4 mg g<SUP>−1</SUP> in a 500 mg L<SUP>−1</SUP> NaCl aqueous solution with a larger charge efficiency and an ideal recycling performance. These enhanced capacitive deionization performances of the sandwich-like nitrogen-doped graphene electrodes are attributed to the unique “plane-to-porous plane” internetworked architecture. This study offers a promising solution to develop high-performance electrode materials for removal of ions from saline water.</P>

INFLUENCE OF INLET WATER INJECTION ON ENERGY CONSERVATION AND EMISSION OF GASOLINE ENGINE

Xu Jiangtao,Zhou Zhiyuan,Jiang Liyi,Zhou Haojie,Zhang Chuan 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.4

Increased compression ratio of auto engine can effectively improve thermal efficiency. However, the risk of engine knock becomes higher when increasing the intake boosting. In this paper, the role of an inlet Water Injection (WI) system in improving the performance of a spark ignition engine was investigated, which was through a comparative study of Miller cycle with electromagnetic intake valve train (EMIT). The numerical simulation method was developed in AVL BOOST based on the engine test rig, and then the port water injection modelling was introduced. The results showed that when the engine speed was lower than 1800 r/min, the water spray scheme had a better effect on the engine performance as compared with the Miller cycle, and such advantage was increasingly significant with the decrease of the speed. This is due to the fact that the water injection takes into account the temperature reduction in the cylinder. When the engine speed was over 1800 r/min, it had a negative impact on engine performance with IWI due to the excessive suppression of combustion. This study provides a theoretical basis for design and research of gasoline engines