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Discreteness of Flux Groups

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Acta Mathematica Sinica,English Series 2006年第1期22卷 115-122页

作者： Yong Seung cho Myung Im LIM Department of Mathematics Ewha Women's-University Seoul 120-750 Korea

Let （M, ω） be a closed symplectic 2n-dimensional manifold. Donaldson in his paper showed that there exist 2m-dimensional symplectie submanifolds （V^2m,ω） of （M,ω）, 1 ≤m ≤ n - 1, with （m - 1）-equivalent inclusions. On the basis of this fact we obtain isomorphic relations between kernel of Lefschetz map of M and kernels of Lefschetz maps of Donaldson submanifolds V^2m, 2 ≤ m ≤ n - 1. Then, using this relation, we show that the flux group of M is discrete if the action of π1 （M） on π2（M） is trivial and there exists a retraction r ： M→ V, where V is a 4-dimensional Donaldson submanifold. And, in the symplectically aspherical case, we investigate the flux groups of the manifolds.

关键词： Symplectic diffeomorphisms Flux Symplectically aspherical manifold Donaldson submanifold

An Empirical Study on the Effectiveness of Adversarial Examples in Malware Detection

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3535-3563页

作者： Younghoon Ban Myeonghyun kim Haehyun cho School of Software Soongsil UniversitySeoul06978Korea

Antivirus vendors and the research community employ Machine Learning(ML)or Deep Learning(DL)-based static analysis techniques for efficient identification of new threats,given the continual emergence of novel malware *** the other hand,numerous researchers have reported that Adversarial Examples(AEs),generated by manipulating previously detected malware,can successfully evade ML/DL-based *** antivirus systems,in particular,have been identified as vulnerable to such *** paper firstly focuses on conducting black-box attacks to circumvent ML/DL-based malware *** attack method utilizes seven different perturbations,including Overlay Append,Section Append,and Break Checksum,capitalizing on the ambiguities present in the PE format,as previously employed in evasion attack *** directly applying the perturbation techniques to PE binaries,our attack method eliminates the need to grapple with the problem-feature space dilemma,a persistent challenge in many evasion attack *** a black-box attack,our method can generate AEs that successfully evade both DL-based and ML-based ***,AEs generated by the attack method retain their executability and malicious behavior,eliminating the need for functionality *** thorogh evaluations,we confirmed that the attack method achieves an evasion rate of 65.6%against well-known ML-based malware detectors and can reach a remarkable 99%evasion rate against well-known DL-based malware ***,our AEs demonstrated the capability to bypass detection by 17%of vendors out of the 64 on VirusTotal(VT).In addition,we propose a defensive approach that utilizes Trend Locality Sensitive Hashing(TLSH)to construct a similarity-based defense *** several experiments on the approach,we verified that our defense model can effectively counter AEs generated by the perturbation *** conclusion,our defense model alleviates the limitation of the mos

关键词： Malware classification machine learning adversarial examples evasion attack cybersecurity

Characterization of a β-1,3-glucan recognition protein from the beet armyworm, Spodoptera exigua （Insecta： Lepidoptera： Noctuidae）

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Insect Science 2013年第5期20卷 575-584页

作者： kyeongrin Bang Sujin Park Saeyoull cho Department of Applied Biology College of Agriculture and Life Science Agriculture and Life Sciences Research Institute Kangwon National University Chuncheon CHA Cancer Institute CHA University 605 Yeoksam-dong Gangnam-gu Seoul 135-081 Korea

The β-1,3-glucan recognition protein gene from Spodoptera exigua （SeβGRP） was cloned and characterized. The cDNA of this gene is 1？644 nucleotides in length and the predicted polypeptide is 491 amino acids （aa） in length, with a calculated molecular mass of 54.8 kDa. The first 22 aa encode a predicted secretion signal peptide. A BLAST search, multiple sequence alignment, and phylogenetic analysis of the aa sequence of SeβGRP revealed that this protein is most similar to the β-1,3-glucan recognition protein （βGRP） family of pattern recognition proteins. Using reverse-transcription polymerase chain reaction, we detected the presence of SeβGRP transcripts in the egg, larval, pupal, and adult stages of S. exigua. In addition, the SeβGRP transcript was expressed in all the tissues examined including the brain, hemocytes, fat body, intestine, and cuticle. There were no changes in SeβGRP mRNA levels in larvae infected with ultraviolet （UV）-killed Escherichia coli DH5α compared with the control larvae inoculated with the water; however, SeβGRP mRNA levels were markedly elevated 4–8 h after infection and slightly induced 12–24 h after infection in larvae injected with UV-killed Fusarium oxysporum. This may be because β-1,3-glucan is the main component of the cell wall of F. oxysporum, but not E. coli DH5α.

关键词： β-1,3-glucan recognition protein Fusarium oxysporum immune,Spodoptera exigua

Angelica tenuissima Nakai Ameliorates Cognitive Impairment and Promotes Neurogenesis in Mouse Model of Alzheimer's Disease

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Chinese Journal of Integrative Medicine 2018年第5期24卷 378-384页

作者： Minji choi Younghyurk Lee Seung-Hun cho Department of Psychiatry Hospital of Korean Medicine Kyung Hee University Medical Center

Objective: To research Angelica tenuissima Nakai(ATN) for use in novel Alzheimer’s disease(AD) therapeutics. Methods: The effect of a 30% ethanol extract of ATN(kH032) on AD-like cognitive impairment and neuropathological and neuroinflammatory changes induced by bilateral intracerebroventricular injections of β-amyloid(Aβ) peptide(Aβ1-42) was investigated. Male C57 Bl/6 mice were randomly divided into 4 groups, 10 in each group. kH032-treated groups were administrated with a low or high dose of kH032(50 and 200 mg/kg, respectively), intragastrically for 16 days; distilled water was applied in the sham and negative groups. Open field test, Y maze and Morris water maze test were used for behavior test and cognitive ability. In addition, the neuroprotective effects of kH032 in Aβ1-42-infused mice on the histopathological markers [neuronspecific nuclear protein(Neu N), Aβ1-42] of neurodegeneration were examined. The levels of glial fibrillary acidic protein(GFAP), Neu N, phosphorylation extracellular signal-regulated kinase(ERk)/ERk, brain-derived neurotrophic factor(BDNF), phosphorylation c AMP response element-binding(CREB)/CREB protein expression were measured by Western blot. Results: kH032 treatment ameliorated cognitive impairments, reduced the overexpression of Aβ1-42, and inhibited neuronal loss and neuroinflammatory response in the Aβ1-42-infused mice. Moreover, kH032 treatment enhanced BDNF expression levels in the hippocampus. Finally, kH032 treatment increased phosphorylation of ERk1/2 and CREB, vital for ERk-CREB signaling. Conclusions: kH032 attenuated cognitive deficits in the Aβ1-42-infused mice by increasing BDNF expression and ERk1/2 and CREB phosphorylation and inhibiting neuronal loss and neuroinflammatory response, suggesting that kH032 has therapeutic potential in neurodegenerative disorders such as AD.

关键词： Alzheimer's disease Angelica tenuissima Nakai beta amyloid cognitive impairment neurogenesis

Influence of different nitrogen application on flour properties,gluten properties by HPLC and end-use quality of korean wheat

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Journal of Integrative Agriculture 2018年第5期17卷 982-993页

作者： Seong-Woo cho chon-Sik kang Taek-Gyu kang kwang-Min cho Chul Soo Park Department of Crop Science and Biotechnology Chonbuk National University National Institute of Crop Science Rural Development Administration Research Center of Bioactive Materials Chonbuk National University

This study was performed to identify how the different levels of nitrogen application affected the variances of gluten properties and end-use qualities and the differences of variances among korean wheat cultivars. Protein and dry gluten content, SDS sedimentation volume and water absorption of Mixolab increased as nitrogen application increased. This ratio of the increase was higher in korean wheat cultivars for bread than in korean wheat cultivars for noodles and cookies. The proportion of（α＋β）-gliadin measured by reversed-phase high-performance liquid chromatography（RP-HPLC） increased, but the proportion of ω-and γ-gliadin decreased as the protein content increased. The korean wheat cultivars for bread showed a high proportion of（α＋β）-gliadin increase, the korean cultivars for noodles had a high proportion of γ-gliadin decrease and the korean wheat cultivars for cookies had a high proportion of ω-gliadin decrease. However, there was no variation of the component in the proportion of glutenin component measured by RP-HPLC, even though the protein content was increased, but all of the protein fractions measured by size exclusion（SE）-HPLC were increased. The soluble monomeric protein showed a high proportion of korean wheat cultivars for bread by the increase of protein content. Bread loaf volume increased by the increase of protein content but there were no variances in the ratio of increase among korean wheat cultivars. The cookie diameter decreased with the increase of protein content, and this ratio of decrease was the highest in korean wheat cultivars for cookies. The hardness of cooked noodles also increased by the increase of protein content but there were no variations in springiness and cohesiveness. The decrease proportion of ω-gliadin affected the increase of bread loaf volume, the hardness of cooked noodles, and the decrease of cookie diameter.

关键词： wheat gluten end-use quality cultivar nitrogen application

Simple method for extracting the seasonal signals of photochemical reflectance index and normalized difference vegetation index measured using a spectral reflectance sensor

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Journal of Integrative Agriculture 2021年第7期20卷 1969-1986页

作者： Jae-Hyun RYU Dohyeok OH Jaeil cho Department of Applied Plant Science Chonnam National UniversityGwangju 61186Republic of Korea

A spectral reflectance sensor(SRS)fixed on the near-surface ground was developed to support the continuous monitoring of vegetation indices such as the normalized difference vegetation index(NDVI)and photochemical reflectance index(PRI).NDVI is useful for indicating crop growth/phenology,whereas PRI was developed for observing physiological ***,the seasonal change patterns of NDVI and PRI are two valuable pieces of information in a crop-monitoring ***,capturing the seasonal patterns is considered challenging because the vegetation index values estimated by the reflection from vegetation are often governed by meteorological conditions,such as solar irradiance and ***,unlike growth/phenology,the physiological condition has diurnal changes as well as seasonal *** study proposed a novel filtering method for extracting the seasonal signals of SRS-based NDVI and PRI in paddy rice,barley,and ***,the measurement accuracy of SRSs was compared with handheld spectrometers,and the R^(2)values between the two devices were 0.96 and 0.81 for NDVI and PRI,***,the experimental study of threshold criteria with respect to meteorological variables(i.e.,insolation,cloudiness,sunshine duration,and precipitation)was conducted,and sunshine duration was the most useful one for excluding distorted values of the vegetation *** data processing based on sunshine duration,the R^(2)values between the measured vegetation indices and the extracted seasonal signals of vegetation indices increased by approximately 0.002–0.004(NDVI)and 0.065–0.298(PRI)on the three crops,and the seasonal signals of vegetation indices became noticeably *** method will contribute to an agricultural monitoring system by identifying the seasonal changes in crop growth and physiological conditions.

关键词： photochemical reflectance index normalized difference vegetation index vegetation remote sensing spectral reflectance sensor

Silicone-coated polyimide films deposited by surface dielectric barrier discharges

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Plasma Science and Technology 2019年第1期21卷 93-99页

作者： Junggil kIM Yunjung kIM Sangjin kIM Guangsup cho Department of Electrical and Biological Physics Kwangwoon University

Hybrid dielectric barrier discharges are investigated for plasma generated on the surface of a dielectric layer, where two conducting electrodes of high voltage and ground are formulated on the upper and bottom surfaces. Using a flexible thin polyimide-film of a thickness ranging from 25 to 125 μm, a plasma is generated with a voltage of about 1 kV and a frequency of 40 ***, the surface of the dielectric layer was etched through a chemical reaction involving plasma oxygen radical species, and thus the polyimide films failed readily, resulting in dielectric breakdown within short operating time ranging from a few minutes to several tens of minutes,based on the film thicknesses of 25 μm and 125 μm, respectively. These plasma erosions were prevented by coating the polyimide surface with a 25 μm thick silicone paste. The siliconecoated film surface was then reinforced remarkably against plasma erosion as the organic polymer was vulnerable to chemical reaction of the plasma species, while the inorganic silicone exhibited a high chemical resistance against plasma erosion.

关键词： plasma discharge atmospheric pressure nonthermal plasma polyimide film plasma erosion

Efective Object Identification and Association by Varying Coverage Through RFID Power Control

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Journal of Computer Science & Technology 2014年第1期29卷 4-20页

作者： Shung Han cho kyung Hoon kim Sangjin Hong IEEE System LSI Business Samsung Electronics Department of Electrical and Computer Engineering Stony Brook University

This paper presents an effective power scheduling strategy for energy efficient multiple objects identification and association. The proposed method can be utilized in many heterogeneous surveillance systems with visual sensors and RFID （radio-frequency identification） readers where energy efficiency as well as association rate are critical Multiple objects positions and trajectory estimates are used to decide the power level of RFID readers. Several key parameters including the time windows and the distance separations are defined in the method in order to minimize the effects of RFID coverage uncertainty. The power cost model is defined and incorporated into the method to minimize energy consumption and to maximize association performance. The proposed method computes the power cost using the range of the outermost position for possible single association and group associations at every sampling time. An RFID reader is activated with the proper coverage range when the power cost for the current time is lower than the power cost for the next time sample. The simplicity of the power cost model relieves the problematic combinatorial comparisons in multiple object cases. The performance comparison simulation with the minimum and maximum energy consumption shows that the proposed method achieves fast single associations with less energy consumption. Finally, the realistic comparison simulation with the fixed range RFID readers demonstrates that the proposed method outperforms the fixed ranges in terms of single association rate and energy consumption.

关键词： object association RFID power control power scheduling visual sensor collaboration

Microstructure comparison of Zk60 alloy under casting,twin roll casting and hot compression

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Transactions of Nonferrous Metals Society of China 2010年第5期20卷 763-768页

作者：王守仁王敏 kANG Suk-bong cho Jae-hyung School of Mechanical Engineering University of Ji'nan School of Materials Science and Engineering Shandong University korea Institute of Materials Science 66 Sangnam-dongChangwon 641010Korea

The microstructures of Zk60 alloy under conventional direct as-casting (DC),twin roll casting (TRC) and twin roll casting followed by hot compression (TRC-HC) were analyzed by optical morphology (OM),electron backscatter diffraction (EBSD) and X-ray diffraction (XRD).The deformation condition of hot compression is 350 ℃,0.1 s?*** microstructural evolution under TRC-HC deformation followed by annealing at different temperatures and time was *** results show that TRC provides more modified microstructure compared with *** are found in TRC processing;dynamic recrystallization (DRX),shear bands and twins are found in TRC-HC.A short annealing time has little effect on hardness,while during a long time annealing,it is found that low annealing temperatures increase the micro-hardness and high temperature decreases it.

关键词： microstructural evolution anneal dynamic recrystallization static recrystallization twin-roll casting hot compression magnesium alloy Zk60