Magnetic Properties of Ordered Fe/Pt Multilayer Thin Films

Li Fei,Nguyen Dan Phuong,Young-Min Lee,Chan-Woo Park,Bon-Heun Koo,Chan-Gyu Lee 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Structure and Magnetic Properties of Fe-Pt Film Electrodeposited by Diffusion Control (초)

( Li Fei ),( Tae Hoon Kim ),( Bon Heun Koo ),( Yasunori Hayashi ),( Chan Gyu Lee ) 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

Energy Saving in Cluster-Based Wireless Sensor Networks through Cooperative MIMO with Idle-Node Participation

Li Fei,Qiang Gao,Jun Zhang,Gang Wang 한국통신학회 2010 Journal of communications and networks Vol.12 No.3

In cluster-based wireless sensor networks, the energy could be saved when the nodes that have data to transmit participate in cooperative multiple-input multiple-output (MIMO). In this paper, by making the idle nodes that have no data to transmit participate in the cooperative MIMO, it is found that much more energy could be saved. The number of the idle nodes that participate in the cooperative MIMO is optimized to minimize the total energy consumption. It is also found that the optimal number of all the nodes participating in cooperative communication does not vary with the number of nodes that have data to transmit. The proposition is proved mathematically. The influence of long-haul distance and modulation constellation size on the total energy consumption is investigated. A cooperative MIMO scheme with helpnode participation is proposed and the simulation results show that the proposed scheme achieves significant energy saving.

한중 무용전공 대학생의 무용동기와 무용몰입, 무용정서표현이 무용만족에 미치는 영향

LI FEI,윤미라 경희대학교 학술단체협의회 2023 高凰論集 Vol.73 No.-

무용학과는 다른 학문에 비해 이론과 실기를 동시에 요구하기 때문에 만족도에 대해 고려해야 할 요소가 다양하다. 무용은 자신의 신체를 통해 내면을 표현하는 예술로서 자기표현과 신체활동의 기회를 동시에 주어진다는 점에서 타학문과는 다른 양상을 보인다. 본 연구의 목적은 무용만족에 영향을 미칠 수 있는 무용동기를 규명하고, 무용몰입과 무용정서표현이 매개적 역할을 하는지를 규명하는 데 있다. 이후, 교육서비스품질의 조절효과를 확인하여 중국과 한국의 무용 교육과정의 차이를 살펴보고자 한다. 이를 위해 SPSS와 Process Macro를 이용하여 빈도분석, 기술통계, 차이검증, 상관분석, 구조모형분석을 실시하였다. 분석 결과, 중국대학생은 타율적인 동기에 의한 외적동기가 높고 주관적인 만족감을 얻기 위해 무용몰입이나 정서적 표현에 집중하기 보단 개인의 만족감을 얻기 위해 무용을 하는 것으로 나타났다. 특히 중국대학생은 개인차원의 만족도를 중시한 반면, 한국대학생은 자신이 하고자 하는 욕구로 인한 내적인 동기가 높았고 무용 활동을 통해 자신의 역량을 최대한 반영하기 위해 공연한다는 점을 도출하였다. 한국대학생은 교육과정의 질을 중시한다는 점에서 중국과 한국의 교육과정의 질에 차이가 있다는 의견이 제기되었다. Since the dance department requires both theory and practice at the same time compared to other disciplines, there are various factors to consider about satisfaction. Dance is different from other studies in that it gives opportunities for selfexpression and physical activity at the same time as an art that expresses the inside through one's body. The purpose of this study is to identify dance motivation that can affect dance satisfaction and to identify whether dance flow and dance emotional expression play a mediating role. Then, the moderating effects of education service quality were examined to examine the differences between Chinese and Korean dance curriculums, and frequency analysis, descriptive statistics, difference verification, correlation analysis, and structural model analysis were conducted using SPSS and Process Macro. As a result of the analysis, it was found that Chinese university students had high external motivation due to other motivations and danced to gain personal satisfaction rather than focusing on dance flow or emotional expression in order to obtain subjective satisfaction. In particular, Chinese university students valued individual satisfaction, while Korean university students had high internal motivation due to their desire to perform and performed to reflect their capabilities as much as possible through dance activities. It was suggested that there is a difference in the quality of the curriculum between China and Korea in that Korean university students emphasize the quality of the curriculum.

Green Cooperative Sensing Scheme in Heterogeneous Networks

( Lifei Shen ),( Jian Liu ),( Xinxin Tan ),( Lei Wang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.2

Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

Investigation of natural gas flooding and its channelling prevention as enhanced oil recovery method

Lifei Dong,Miao Wang,Wei Wang,Hun Lin 한국자원공학회 2021 Geosystem engineering Vol.24 No.3

The natural gas can improve the flooding effect as its excellent flow property and dissolution ability, but it is also easily to form the serious gas channelling when injecting gas continuously. In order to decribe the advantages and disadvantages of natural gas flooding, the oil dispalcement experiments of injecting natural gas after water flooding with different permeability cores are done. The natural gas channelling and its prevention manner are discussed by theoretical and experimental analysis, and the water alternating natural gas (WAG) injection is introduced. The results show that the natural gas flooding can enhance oil recovery after water flooding in different permeability reservoirs, especially in lower permeability reservoirs. The continuously natural gas flooding can easily form and develop the gas channeling. It takes only 0.13 PV to 0.45 PV natural gas injection to form the gas channelling, and spends 0.5 PV to 1.5 PV injection to develop the gas channelling for making the gas-liquid ratio reaching to 200 in the cores with the permeability from 6.876 × 10−3μm2 to 540.124 × 10−3μm2. The WAG injection with the WAG cycle below 2 can prevent the natural gas channelling and keep the good natural gas utilisation in low/ultra-low permeability reservoirs.

Interference intention classification of moving obstacles used for USV collision avoidance

Song Lifei,Sun Hao,Xu Kaikai,Huang Liang,Chen Houjing 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

Unmanned Surface Vessels (USV) may interfere with ships in the same lane during navigation and may be affected by ships that actively collide or intercept the USV. Evidently, the latter poses a greater threat than the former. This paper proposes the concept of active and inactive interference. It is necessary for the USV to accurately classify the vessels’ intentions to conduct a suitable collision avoidance strategy. However, the existing research on collision avoidance of USV focuses on avoiding moving obstacles and rarely considers the interference intention of dynamic obstacles for USV when choosing collision avoidance strategies. This paper proposes an algorithm to recognize the interference intention of ships by combining visual classification with a Support Vector Machine (SVM). First, a Convolutional Neural Network (CNN) is proposed to distinguish the merchant ship from a high-performance ship that actively interferes with the USV with high probability. A high-dimensional feature dataset was designed to illustrate the navigation characteristics of an obstacle, and Principal Component Analysis (PCA) was then employed to reduce the dimensionality of the dataset for obstacle classification. A modified SVM is presented to classify obstacles into active and inactive interference intention categories. Moreover, an escape algorithm based on an improved artificial potential field method is proposed for vessels with active interference. The simulation and experimental results clearly show that the USV can successfully identify the interference intention of obstacles and adopt a specific collision avoidance strategy for obstacles with active interference intentions. Using this algorithm, the USV can safely avoid obstacles with different interference intentions.

民族声乐多元化演唱风格的形成研究

王俪霏(Lifei Wang) YIXIN 출판사 2024 Journal of Humanities and Social Sciences Vol.2 No.1

新时代背景下,我国民族声乐实现了多元化的创新发展,探索民族声乐的发展和传承有助于了解我国民族声乐在多元文化背景下的发展现状。在我国音乐体系中,民族声乐具有极高的艺术价值,不仅代表着中华民族的艺术审美取向,同时更能够反映出诸多民族发展的人文历史。本文将从民族声乐多元化演唱风格的历史演变、影响因素和艺术表现进行研究,为中国民族声乐的后续研究提供借鉴。 In the musical system of our country, ethnic vocal music holds extremely high artistic value. It not only represents the artistic aesthetic orientation of the Chinese nation but also reflects the human history of the development of various ethnic groups. The historical evolution of the diverse singing styles in ethnic vocal music has not only brought forth numerous influencing factors but has also propelled the artistic expression of diverse singing styles in ethnic vocal music. Based on this, this paper will conduct a study on the formation of diverse singing styles in ethnic vocal music from the three dimensions mentioned above, aiming to achieve better development of ethnic vocal music.

Identification and Characterization of an Anti-fungi Fusarium oxysporum f. sp. cucumerium Protease from the Bacillus subtilis Strain N7

Yi Luo,Lifei Sun,Zhen Zhu,Wei Ran,Qirong Shen 한국미생물학회 2013 The journal of microbiology Vol.51 No.3

A newly discovered alkaline antifungal protease named P6 from Bacillus subtilis N7 was purified and partially characterized. B. subtilis N7 culture filtrates were purified by 30–60% (NH4)2SO4 precipitation, anion-exchange chromatography and gel filtration chromatography. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE) revealed a single band of 41.38 kDa. Peptide sequence of protease P6 was determined using a 4800 Plus MALDI TOF/TOFTM Analyzer System. Self-Formed Adaptor PCR (SEFA-PCR) was used to amplify the 1,149 bp open read frame of P6. Dimensional structure prediction using Automatic Modeling Mode software showed that the protease P6 consisted of two β-barrel domains. Purified P6 strongly inhibited spore and mycelium growth of Fusarium oxysporum f. sp. cucumerium (FOC) by causing hypha lysis when the concentration was 25 μg/ml. Characterization of the purified protease indicated that it had substrate specificity for gelatin and was highly active at pH 8.0–10.6 and 70°C. The P6 protease was inhibited by EDTA (2 mmol/L), phenyl methyl sulfonyl fluoride (PMSF, 1 mmol/L), Na+, Fe3+, Cu2+, Mg2+ (5 mmol/L each) and H2O2 (2%, v/v). However, protease activity was activated by Ca2+, K+, Mn2+ (5 mmol/L each), mercaptoethanol (2%, v/v) and Tween 80 (1%, v/v). In additon, activity was also affected by organic solvents such as acetone, normal butanol and ethanol, but not hexane (25%, v/v each).

Influence of In-Plane Simple Shear Strain on the Grain Orientation Regulation and Stretch Formability of Pre-twinned AZ31 Magnesium Alloy Sheet

Liangliang Xue,Lifei Wang,Pengbin Lu,Qiang Zhang,Hua Zhang,Guangsheng Huang,Liwei Lu,Liuwei Zheng,Hanuma Reddy Tiyyagura,Hongxia Wang,Shuyong Jiang,Kwang Seon Shin 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

Pre-twin is widely accepted as an efficient method for weakening the basal texture to improve the plasticity of magnesium alloys, particularly for formability. However, the enhancement is limited since the largest Schmid factor (SF) of basal slip cannot be achieved. In-plane simple shear strain is used to control the twin orientation in accordance with Schmid law to further decrease the basal texture and improve the formability of the Mg alloys sheet. Consequently, secondary regulation of initial twin orientation (SRITO) technology, a novel combination procedure, was developed. In this method, the AZ31 Mg alloys sheet is compressed to pre-twins with various volumes (1%, 3%, and 5%), then the twin orientation is regulated by in-plane simple shear strain for the second time. Compared with the as-received sample, the average fracture elongation of the annealed sample with the best properties improves from 15.3 to 28.8%, and the Erichsen value increases from 2.8 to 6.1 mm due to the regulation of twin orientation.