AI 기술을 적용하여 동물 입양을 위한 새로운 서비스 디자인 생성

Guo,Haoyue,Zhang Muxin,Chen Xie,Li Yueyi,Liang Lan,Pan Young Hwan 한국서비스디자인학회 2020 한국서비스디자인학회 학술대회자료집 Vol.2020 No.-

Investigation of Quench Sensitivity and Microstructure Evolution During Isothermal Treatment in 2195 Al–Li Alloy

Zhiwu Zhang,Youping Yi,Wen You,Shiquan Huang,Yonglin Guo,Hailin He 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

To investigate the quenching sensitivity of the 2195 Al–Li alloy rolled sheet and guide the design of the quenching process,the time–temperature-property (TTP) curves of this material were researched through interrupted quenching experiments. The differential scanning calorimetry (DSC) and transmission electron microscope (TEM) were used to characterize theevolution of precipitates during isothermal treatment. The results of this essay demonstrated that the nose temperature of 2195Al–Li alloy is around 370 °C and the temperature range of quenching sensitivity is 340 °C to 400 °C. The microstructureobservation revealed that the T1particles precipitate and grow rapidly at the temperature from 340 to 400 °C, which is dueto the high nucleation rate of phase and fast solute diffusion kinetics, especially at the nose temperature. The needle-shapedθ′/θ″ and T1particles grow up quickly as the isothermal preservation time prolonged, leading to the decrease of the supersaturatedsolid solution of the matrix. This will reduce the number of the age-induced precipitate and weaken the subsequentage hardening effect. Therefore, the rate of cooling should be increased in the quenching sensitivity range (340–400 °C) toinhibit the precipitation of the second phase and obtain excellent mechanical properties. While in other temperature ranges,the cooling rate should be decreased appropriately to reduce residual stress. The appropriate average cooling rate is recommendedto be around 13 °C s−1 at the temperature from 340 to 400 °C.

Effects of Quenching Methods and Aging Processes on the Crushing Properties and Microstructure of Al–Zn–Mg Alloy Thin-Walled Square Extrusions

Hui Guo,Jin Zhang,Cheng Wang,Yun‑lai Deng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the effects of different (online quenching and offline quenching) quenching methods and aging processes (T6and T73) on the crashworthiness and microstructural evolution of three Al–Zn–Mg alloys (G1–G3) were studied by conductingtensile test and axial compression tests at room temperature, combined with optical metallography, electron back scattereddiffraction, and transmission electron microscopy microstructural observations. The obtained results revealed that thecrushing properties of three different Al–Zn–Mg alloys subjected to different quenching methods and aging processes weresignificantly different. Their crushing energy absorption of are ranked as follows: G1 > G3 > G2. The highest total energyabsorption gap (between T6 and T73) is the G1 alloy, and the lowest one is the G3 alloy. The largest total energy absorptiongap between the two quenching methods is the G3 alloy, and the smallest one is the G1 alloy. The G2 alloy with the largesttotal amount of Zn + Mg has the highest number density of matrix precipitates, the largest precipitate gap (between T6 andT73) and the smallest precipitate gap between the two quenching methods. The G3 alloy with the largest Zn/Mg ratio hasthe smallest number density of matrix precipitates, the minimum precipitation gap (between T6 and T73) and the maximumprecipitation gap between the two quenching methods. The G1 alloy with the lowest Zn/Mg ratio has the smallest size ofgrain boundary precipitates and PFZ width, while their largest values are obtained for the G3 alloy with the maximum Zn/Mg ratio. As a crushing resistant structural material, the crushing properties is improved without reducing the strength. Theratio of Zn/Mg should be controlled within the range of 4.57–6.15, while the total amount of Zn + Mg should be controlledwithin the range of 6.18–7.01.

중국전통시대 민법상의 논쟁점

張國華 慶北大學校 法學硏究所 1998 법학논고 Vol.14 No.-

Cantonese morning tea (Yum Cha): a bite of Cantonese culture

Guo Kaiwei,Zhang Na,Zhang Jianfen,Zhang Manman,Zhou Mingzhu,Zhang Yue,Ma Guansheng 한국식품연구원 2023 Journal of Ethnic Foods Vol.10 No.12

Among various types of breakfast in China, Cantonese morning tea (Yum Cha) is unique in its form and feature. Morning tea is a Cantonese tradition of morning activity, originated in the Qing dynasty. After years of change, it has evolved to the current form, serving an assortment of small dishes (dim sum) alongside Chinese tea. The classification of Chinese tea is based on the colors, shapes, aroma, and fermentation degree. Several types of dim sum dishes in Guangdong are categorized according to the region, ingredients selection, taste, and cooking methods. Yum Cha has a unique etiquette that is different from the folk cultures in other areas. Morning tea plays an essential role in influencing the dietary patterns and eating habits of Cantonese people. In addition, morning tea supports social interactions and connections of daily human life, providing a practical and acceptable channel for old friendships to nurture and new bonds to build. As a symbol of local culture, morning tea shapes Cantonese people physically and mentally. Therefore, the Yum Cha culture should be valued and propagated.

Overexpression of NDRG2 Can Inhibit Neuroblastoma Cell Proliferation through Negative Regulation by CYR61

Zhang, Zhi-Guo,Li, Gang,Feng, Da-Yun,Zhang, Jian,Zhang, Jing,Qin, Huai-Zhou,Ma, Lian-Ting,Gao, Guo-Dong,Wu, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.

A 2 GS/s, 6-bit DAC for UWB Applications In 0.18 ㎛ CMOS Technology

Yi Zhang,Zhonghua Liu,Changchun Zhang,Yufeng Guo,Ying Zhang,Xiaopeng Li,Youtao Zhang,Hao Gao 대한전자공학회 2019 Journal of semiconductor technology and science Vol.19 No.6

To satisfy higher and higher transmission rate and broadband requirement of modern communication, high-speed, low-resolution Digital-to-Analog Converters (DACs) becomes the key element. In this paper, the design of a 2 GS/s, 6 bit DAC without calibration for Ultra-wideband (UWB) applications, is presented. The DAC is based on current steering architecture and is segmented with 4 bit unary and 2 bit binary. To realize larger linear range and fast switching, the source degeneration switch is designed instead of the traditional differential switch. The DAC is designed and taped-out in SMIC 0.18 ㎜ CMOS technology and the area is 975 ㎛´ 775 ㎛. The wafer bonding measurement results shows that the DNL is 0.11 LSB, INL is 0.25 LSB. Under a clock frequency of 2 ㎓, the DAC can achieve a SFDR of 51 ㏈ for input signal of 6㎒, and a SFDR of 32.4 ㏈ for Nyquist input while the power consumption is 79 ㎽.

Analog Fault Detection Comparison between Supply Current and Output Voltage

Chaojie Zhang,Guo He,Qiaobin Zhang 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11

In view of the difficulties caused by determining threshold for fault detection of analog circuits, a method based on principal component analysis (PCA) was proposed to overcome these difficulties. The basic model of the proposed method and the general rule for analog fault detection were described in detail. Power supply current test has the advantages that only one test point is needed and there is no need to propagate fault effects to the outputs. Fault detection of analog circuits using PCA of power supply current was evaluated by experiment. The signal filtering and amplifying circuit used in the ultrasonic liquid sensor was selected as the research object. And the detection results using power supply current are compared with those using the output voltage under the same stimulus. The results show that the PCA based method can use the information in both time and frequency domain simultaneously, and it can overcome the difficulty in determining threshold by the expert’s empirical knowledge. These make it a more suitable candidate for fault detection of analog circuits than pure time-domain or pure frequency-domain methods.

Enhancement of transglutaminase production in Streptomyces mobaraensis DSM 40587 by non-nutritional stress conditions: Effects of heat shock, alcohols, and salt treatments

Lili Zhang,Lanwei Zhang,Huaxi Yi,Ming Du,Yingchun Zhang,Xue Han,Zhen Feng,Jingyan Li,Yuehua Jiao,Yanhe Zhang,Chunfeng Guo 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.7

Stress-mediated bioprocess is a strategy designed to enhance biological target productivity. In this study,an attempt was made to enhance transglutaminase (TGase) production by Streptomyces mobaraensis by using different stress conditions including heat shock, alcohols and salt stress. Results showed that the effects of stress on TGase production depended on the type applied. For heat shock, TGase production (1.32 U/ml) was recorded maximum in the culture treated at 48 h post inoculation in water bath at 60 oC for 1 min. For alcohols treatment, the maximum activity of TGase (1.77 and 1.75 U/ml) was obtained when 3% methanol was added into the medium at 0 or 24 h of fermentation. However, a 3.5-fold increased production of TGase (3.8 U/ml) was observed in the medium supplemented with 0.2mol/l MgCl2 compared with the basic medium at the beginning of fermentation. In conclusion, TGase production from S. mobaraensis was improved by heat shock, methanol and salt stress treatments, MgCl2 stress was the most effective.

Research on PN Code Acquisition Strategy

Zhang Bo,Guo Ying,Zhang Dongwei,Li Xia 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.5

PN code acquisition is the key to synchronization in direct-sequence spread-spectrum(DSSS) systems. Aiming at the problems in the process of PN code acquisition, the block diagram of acquisition strategy is illustrated firstly. Then, with the choice of different search mode, determination mode and verification mode in the block diagram, the detection probabilities and false alarm probabilities are presented separately, and the false alarm probability of threshold detection method, the detection probability and false alarm probability of maximum-selection determination method are deduced, and all kinds of acquisition strategies are given. Finally, Simulation results shows that the detection probabilities and false alarm probabilities in theory and experiment is consistent with different acquisition strategy, and so does the validation of detection probabilities by maximum-selection method in multiple dwell times.