Dynamic Instability Analysis of Axially Compressed Castellated Columns

Jin-song Lei,Boksun Kim,Long-yuan Li 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.2

This paper presents an analytical study on the dynamic instability of castellated columns subjected to axial excitation loading. By assuming the instability modes, the kinetic energy and strain energy of the columns and the loss of the potential of the axially applied load are evaluated, from which the mass matrix, stiffness matrix, and geometric stiffness matrix of the system are derived. These matrices are then used for deriving dynamic equations and carrying out the analysis of dynamic instability of castellated columns by using Bolotin’s method. The analytical expression for determining the critical excitation frequency of the columns is derived, which takes account for not only the shear influence of web openings but also the rotary inertia effect on the transverse vibration of the columns. Numerical examples are also provided for illustrating the dynamic instability behaviour of castellated columns when subjected to axial excitation loading. The results show that the consideration of the shear effect in castellated columns results in a shaft of the dynamic instability zone to low frequency side and a reduction of the width of the dynamic instability zone. The shear effect on the dynamic instability zone becomes more significant in the short column than in the long column, and in the wide flange column than in the narrow flange column.

Understanding the Evolution of Cooperation in Distributed Systems

Lei Jin,Xin Jin 한국산학기술학회 2014 SmartCR Vol.4 No.3

The success of distributed systems such as grids and P2P networks lies in cooperation for local resource sharing. The lack of any centralized coordinator and the selfish behaviors of individual machines, however, raise a problem for such cooperation, leaving the prescribed protocol vulnerable to strategic manipulation. The most significant recent advances in distributed systems have therefore been to apply game theory and other branches in economics to model incentives for cooperation, as the first step towards robust protocol design. In this paper, we aim to provide an analytical framework to investigate the evolution of cooperation in distributed systems.

Assessment of cryopreserved sperm functions of Korean native brindled cattle (Chikso) from different region research centers of Korea

Lei Ma,Dae-Jin Jung,Eun-Ju Jung,Woo-Jin Lee,Ju-Mi Hwang,Jeong-Won Bae,Dae-Hyun Kim,Jun Koo Yi,Sang Moo Lee,Jae Jung Ha,Woo-Sung Kwon 한국동물생명공학회(구 한국동물번식학회) 2021 Journal of Animal Reproduction and Biotechnology Vol.36 No.2

Sperm cryopreservation is an important method of assisted reproductive techniques and storing genetic resources. It plays a vital role in genetic improvement, livestock industrial preservation of endangered species, and clinical practice. Consequently, the cryopreservation technique is well organized through various studies, especially on Korean native cattle (Hanwoo). However, the cryopreservation technique of Korean native brindled cattle, which is one of the native cattle species in Korea, is not well organized. Therefore, it is necessary to develop a Supplementary Table technique for the cryopreservation of Korean native brindled cattle. For this purpose, it is important to first evaluate the quality of the currently produced cryopreserved sperm of Korean native brindled cattle. In this study, we randomly selected 72 individual Korean native brindled cattle semen samples collected from 8 different region research centers and used them to evaluate sperm functions. We focused on the quality evaluation of cryopreserved Korean native brindled cattle semen following the measurement of motion kinematics, capacitation status, intracellular ATP level, sperm motility, and cell viability. Then, the values of each of the eight groups were derived from various sperm parameters of nine individual samples, including sperm motility, kinematics, cellular motility, and intracellular ATP levels, which were used to compare and evaluate sperm function. Overall, differences in various sperm parameters were observed between most of the research centers. Particularly, the deviations of motility and motion kinematics were high according to the sample. Therefore, we suggest that it is necessary to develop a standard method for the cryopreservation of Korean native brindled cattle semen. We also suggest the need for sperm quality evaluation of the cryopreserved semen of Korean native brindled cattle before using artificial insemination to attain a high fertility rate.

Petroleum Company’s Technology Commercialization Mode and Evaluation of Commercial Potential Based on Two-tuple Linguistic

Jin Lei,Li Ming,Yu Yuqi,Zhang Cuili 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4

Age-stage, two-sex life tables of the maple poison moth (Lymantria nebulosa Wileman) at different ambient temperatures

Lei Ling,Huang Hui Jing,Yi Jin Yu,Qiu Lin,Ding Wen Bin,He Hua Liang,Yi Tu Yong,Li You Zhi,Xue Jin 한국곤충학회 2021 Entomological Research Vol.51 No.4

The maple poison moth (MPM), Lymantria nebulosa (Wileman), is a Lepidopteran defoliator and one of the most important pests of Liquidambar formosana Hance. The objective of this study was to determine the effects of temperature on the population growth and reproduction of this species. MPM were raised in artificial climate chambers in a laboratory at 21 ± 1°C, 24 ± 1°C, 27 ± 1°C, 30 ± 1°C, 33 ± 1°C and 36 ± 1°C, under a relative humidity (RH) of 70% ± 10% and a 14 L:10D photoperiod, and age-stage, two-sex life tables complied for insects at each temperature. The developmental duration, adult preoviposition period and overall preoviposition period decreased with temperature in a time-dependent manner. The growth curves of the different temperature groups overlapped considerably. The highest larval survival rate (80%) was recorded at 30 ± 1°C. At 36°C only a few eggs hatched and the first instar could not complete the first molt. We consequently regard 36°C as the lethal temperature threshold for this species. Life expectancy decreased with age under all six temperatures. The endogenous growth rate was significantly lower at 21 ± 1°C than at the other temperatures, and was highest in 30 ± 1°C group. The net growth rate of the 30 ± 1°C group was also significantly higher than others. Reproductive parameters were highest at 27 ± 1°C and 30 ± 1°C. Although environmental factors absent from the laboratory environment may limit the generality of our results, they nonetheless provide a theoretical basis for developing integrated control methods for MPM in the wild.

A 3-D Steady-State Analysis of Thermal Behavior in EHV GIS Busbar

Jin Lei,Jian-ying Zhong,Shi-jin Wu,Zhen Wang,Yu-jing Guo,Xin-yan Qin 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

Antioxidant Activities of Polysaccharides Isolated from Sargassum fulvellum in In Vitro and In Vivo

Jin Hwang,Jun-Geon Je,Lei Wang,Young-Sang Kim,Jae Young Oh,Jae Young Ko,You-Jin Jeon,BoMi Ryu 한국식품영양과학회 2020 한국식품영양과학회 학술대회발표집 Vol.2020 No.10

Synthesis of Novel D-Glucose-derived Benzyl and Alkyl 1,2,3-Triazoles as Potential Antifungal and Antibacterial Agents

Jin-Jian Wei,Lei Jin,Kun Wan,Cheng-He Zhou 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

A series of novel glucose derived benzyl and alkyl 1,2,3-triazoles and their hydrochlorides have been synthesized via Cu(I)-catalyzed 1,3-dipolar cycloaddition. All the new compounds were characterized by MS, IR and NMR spectra. The DEPT, APT, ^1H-^1H and ^1H-^13C 2D NMR spectra for some compounds were also recorded. These compounds were evaluated for their in vitro antibacterial activities against Staphylococcus aureus ATCC 29213, Bacillus subtilis,Bacillus proteus, Pseudomonas aeruginosa, Escherichia coli ATCC 25922, and antifungal activities against Candida albicans and Aspergillus fumigatus. The bioactive data revealed that (3R,4S,5S,6S)-2-(hydroxymethyl)-6-methoxy-4,5-bis((1-octyl-1H-1,2,3-triazol-4-yl)methoxy)-tetrahydro-2H-pyran-3-ol 8a exhibited excellent antifungal activity against A. fumigatus with an MIC value of 0.055 mM compared to Fluconazole. It also showed broad inhibitory efficacy against tested bacterial strains with MIC values ranging from 0.049 mM to 0.39 mM.

1-(2-Pyridylazo)-2-naphthol as a synergistic additive for improving throwing power of through hole copper electronic electroplating

Lei Jin,Zhao-Yun Wang,Zhuan-Yun Cai,Jia-Qiang Yang,An-Ni Zheng,Fang-Zu Yang,De-Yin Wu,Dongping Zhan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

In this work, we develop a novel 1-(2-Pyridylazo)-2-naphthol (PAN)-based acidic sulfate copper electronicelectroplating process for compact, homogeneous and conformal copper thickening of throughhole (TH). The adsorption characteristics, electrochemical properties and the interaction mechanismsof three additives (PEG, SPS and PAN) are studied in detail. Scanning electron microscope (SEM) and opticalmicroscope (OM) reveal that PAN can make the copper coating in fine grains and high throwing powerof 90.35% in TH without an overhang phenomenon. Theoretical calculations illustrate that the bindingenergies between additive molecules and copper surface decrease in the order: PAN > SPS > PEG. Cyclic voltammetry experiments at rotating rates of 1200 and 200 r/min prove that PAN itself can accelerateand weakly suppress copper electrodeposition at the center and mouth of TH, respectively. PANbehaves respectively the synergistic and antagonistic effects with PEG at the mouth and center of TH,and the weakly synergistic effects with SPS both at the mouth and center of TH. The addition of PANto the virgin make-up solution (VMS) containing PEG and SPS causes decreasing the relative electriccharge (DQ) at high and low rotating rates from 18.52 ± 0.08% to 8.25 ± 0.05%, which satisfies the closercopper electronic electroplating rate at the center and mouth of TH. The effective and complicated synergisticeffects of the additives PEG, SPS and PAN can achieve compact, homogeneous and conformal copperthickening of TH.

A Novel Approach for the Unit Commitment with Vehicle-to-grid

Jin, Lei,Yang, Huan,Zhou, Yuying,Zhao, Rongxiang Journal of International Conference on Electrical 2013 Journal of international Conference on Electrical Vol.2 No.3

The electrical vehicles (EV) with vehicle-to-grid (V2G) capability can be used as loads, energy sources and energy storage in MicroGrid integrated with renewable energy sources. The output power of generators will be reallocated in the considering of V2G. An intelligent unit commitment (UC) with V2G for cost optimization is presented in this paper. A new constraint of UC with V2G is considered to satisfy daily use of EVs. A hybrid optimiza-tion algorithm combined Binary Particle Swarm Optimization (BPSO) with Lagrange Mul-tipliers Method (LMM) is proposed. The difference between results of UC with V2G and UC without V2G is presented.