Tolerance of Nicotiana tabacum Cultivars Dixie Bright 244-2, McNair 30, and Golden Stock Penish to Strains of Potato Virus Y

박은경,Park Eun Kyung,Gooding G. V. The Korean Society of Plant Pathology 1986 Plant Pathology Journal Vol.2 No.1

The reaction of seven cultivars of Nicotiana tabacum to eight naturally occurring strains of potato virus Y from tobacco and one from potato was determined by mechanical inoculations in greenhouse tests. Dixie Bright 244-2, McNair 3D, and Golden Stock Penish were highly tolerant to three mild strains, two from the United States and one from Korea, and to four severe strains, one each from the United States, West Germany, South Africa, and Korea. They also had some tolerance to a severe strain from Child and one from United States. Virus concentration in infected leaf tissue was virus strain-and cultivar-dependent. 한국을 비롯한 5개국에서 잎담배로부터 8계통, 감자로부터 분리된 1계통 등 모두 9계통의 PVY에 대한 잎담배 품종별 내병성을 온실내에서 조사하였다. 조사된 품종중 Dixie Bright 244-2, McNair 30, 및 Golden Stock Penish 등의 품종은 7가지의 PVY 계통에 대해 높은 내병성 반응을 보였다. 이외 Chile 및 US-NN계통에 대해서도 감수성품종에 비해 내병성을 나타냈다. 품종별 병징의 심, 경에 따른 엽중 바이러스의 농도는 접종된 바이러스 계통과 품종에 다라 다르게 나타나 엽중 바이러스 농도에 따른 내병성 정도 구분은 할 수 없었다.

RF plasma functionalized carbon surfaces for supporting sensor architectures

J.S. Quinton,A. Deslandes,A. Barlow,J.G. Shapter,C. Fairman,J.J. Gooding,D.B. Hibbert 한국물리학회 2008 Current Applied Physics Vol.8 No.3,4

Carbon has a number of properties that make it ideal for use in sensor and electrical applications. Using radio frequency plasma with different precursor gases and operating plasma conditions, it is possible to pre-treat a variety of carbon surfaces in preparation for further molecular attachment, or surface functionalization. Research in our laboratory involves studies on highly ordered pyrolytic graphite (HOPG) as a model carbon substrate and pyrolysed photoresist films (PPF). Plasma treated surfaces have been characterised using a variety of surface sensitive techniques. We will report on results obtained using X-ray photoelectron spectroscopy to probe the chemical nature of the treated surfaces, and hence the extent of treatment. Time of flight secondary-ion mass spectrometry (ToFSIMS) has been utilised to determine the extent of hydrogenation after plasma treatment. Scanning tunnelling microscopy (STM) measurements provide morphological information about the treated surfaces, in particular damage and a severe change in surface structures that may be caused by various plasma treatments. Etching and/or nucleation and growth features are also observed and will be discussed, with the types of features and their distribution strongly dependent on the precursor gas that is used to support the plasma. Carbon has a number of properties that make it ideal for use in sensor and electrical applications. Using radio frequency plasma with different precursor gases and operating plasma conditions, it is possible to pre-treat a variety of carbon surfaces in preparation for further molecular attachment, or surface functionalization. Research in our laboratory involves studies on highly ordered pyrolytic graphite (HOPG) as a model carbon substrate and pyrolysed photoresist films (PPF). Plasma treated surfaces have been characterised using a variety of surface sensitive techniques. We will report on results obtained using X-ray photoelectron spectroscopy to probe the chemical nature of the treated surfaces, and hence the extent of treatment. Time of flight secondary-ion mass spectrometry (ToFSIMS) has been utilised to determine the extent of hydrogenation after plasma treatment. Scanning tunnelling microscopy (STM) measurements provide morphological information about the treated surfaces, in particular damage and a severe change in surface structures that may be caused by various plasma treatments. Etching and/or nucleation and growth features are also observed and will be discussed, with the types of features and their distribution strongly dependent on the precursor gas that is used to support the plasma.

플라즈마 회전전극법에 의한 Al-Cu 합금 분말의 제조

최국선,김진영,이동희 연세대학교 대학원 1991 延世論叢 Vol.27 No.1

The production and characterization of Al-Cu alloy powders by the plasma- rotating-electrode process(PREP) was carried out to determine the influence of operating conditions(rotating speed, and plasma current) and alloy compositions on such particle characteristics as particle size distributon, shape, microstructure, and chemical composition. Each experimental condition showed a particle size range of 75∼353μm with mean sizes of 140∼160μm. The mean particle size of the powders changed with alloy compositions at the same rotating speed and plasma current. Particle shapes were mostly of the ligament type. Microstructures consisted mainly of dendrites, but also lamellar cell in the vicinity of eutectic composition. Al -20wt.% Cu powders of the same size, from even a single atomizing run, showed a wide variety of microstructure due to different thermal and nucleation history. Chemical compositions of alloy powders varied with particle size as a result of the interaction between high temperature plasma gas and material constituents of alloys during powder formation.

304L 오스테나이트 스테인레스강 분말의 소결성에 미치는 Mo의 첨가 영향

최국선,이동희,최왕규 연세대학교 산업기술연구소 1989 논문집 Vol.21 No.2

An investigation of Mo addition effect on the sinterability of 304L austenitic stainless steel powders was carried out by using the compacts of three different Mo contents(0.2 and 5 wt%) and using diffusion couple of same stainless steel and Mo powders. The compacts of pure stainless steel powder showed conventional sintering process. And also. we found the diffusion (alloying) layer, 60㎛, and porosity formation toward stainless steel compact in the vicinity of coupled zone by means of SEM and EDS analysis. The porosity of compacts to which Mo was added, was high compared with no Mo added compacts except early stage of sintering. But in compacts sintered at 1200℃ for 45 min, the abnormal increase of porosity could be understood by "bridging" effect of alloying layer formed during sintering process.

기계적 합금화에 의해 제조된 고규소 Al-Si 합금 나노 결정의 특성

이정일,김일호,홍태환,어순철,양계준,석현광,한만갑,최국선,김준수 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.7

High silicon Al-Si alloys with nanocrystalline structures have been produced by mechanical alloying process. Microstructural changes of the Al-Si alloys were investigated by scanning electron microscopy and the transmission electron microscopy. X-ray diffraction analysis was also made to characterize the lattice constant, crystallite size and misfit strain. It was found that the effective milling time by attrition milling was about 12hours for Al-70 wt%Si alloy system. The Al and Si crystallites were reduced to about 30 nm and 70 nm, respectively, by the mechanical alloying for more than 12hours. The misfit strains increased with milling time UD to 240 hours, and saturated to 5.73×10^(-3) for Al and Si crystallites, respectively.

SUNSHINE, EARTHSHINE AND CLIMATE CHANGE I. ORIGIN OF, AND LIMITS ON SOLAR VARIABILITY

GOODE PHILIP R.,DZIEMBOWSKI W. A. The Korean Astronomical Society 2003 Journal of The Korean Astronomical Society Vol.36 No.suppl1

Changes in the earth's climate depend on changes in the net sunlight reaching us. The net depends on the sun's output and earth's reflectance, or albedo. Here we develop the limits on the changes in the sun's output in historical times based on the physics of the origin of solar cycle changes. Many have suggested that the sun's output could have been $0.5\%$ less during the Maunder minimum, whereas the variation over the solar cycle is only about $0.1\%$. The frequencies of solar oscillations (f- and p-modes) evolve through the solar cycle, and provide the most exact measure of the cycle-dependent changes in the sun. But precisely what are they probing? The changes in the sun's output, structure and oscillation frequencies are driven by some combination of changes in the magnetic field, thermal structure and velocity field. It has been unclear what is the precise combination of the three. One way or another, this thorny issue rests on an understanding of the response of the solar structure to increased magnetic field, but this is complicated. Thus, we do not understand the origin of the sun's irradiance increase with increasing magnetic activity. Until recently, it seemed that an unphysically large magnetic field change was required to account for the frequency evolution during the cycle. However, the problem seems to have been solved (Dziembowski, Goode & Schou 2001) using f-mode data on size variations of the sun. From this and the work of Dziembowski & Goode (2003), we suggest that in historical times the sun couldn't be much dimmer than it is at activity minimum.

Improvement to Dormant Validators in Private Ethereum IoT Blockchain Network

Goodness Oluchi Anyanwu,Ikechi Saviour Igboanusi,Dong-Seong Kim 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.6

Novel hyper-tuned ensemble Random Forest algorithm for the detection of false basic safety messages in Internet of Vehicles

Goodness Oluchi Anyanwu,Cosmas Ifeanyi Nwakanma,Jae Min Lee,Dong-Seong Kim 한국통신학회 2023 ICT Express Vol.9 No.1

Detection of nodes disseminating false data is a prerequisite for effective deployment of Internet of Vehicles (IoV) services. This work proposed a novel hyper-tuned ensemble Random Forest (Ens. RF) algorithm to detect false basic safety messages in IoV. Performance evaluation was done using the Vehicular Reference Misbehavior (VeReMi) dataset comprising data-centric misbehavior evaluation for vehicular networks. For validation, a comparative analysis of the performance of the proposed “Ens. RF” model, five machine learning algorithms implemented in this work, and state-of-the-art ML models from related literature was presented. The performance metrics considered are time efficiency and validation accuracy for overall misbehavior classification. Also, the results confirmed the irrelevance of data balancing in real-life scenarios. Finally, we assess the performance of our proposed system for detecting each falsification scenario using precision and recall. The result shows that the proposed algorithm outperformed others with a validation accuracy of 99.60% and a negligible 604 misclassifications out of 153,730 points.

An Ensemble Learning Based Approach to Position Falsification Detection in Internet of Vehicles

Goodness Oluchi Anyanwu,Cosmas Ifeanyi Nwakanma,Jae-Min Lee,Dong-Seong Kim 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.6

Misbehaviour detection is seen as an important development to guarantee that vehicles are certified on the IoV network. To solve this, a recent dataset known as the VeReMi dataset was created. In this paper, we presented an Optimized Ensemble Neural Network approach using MATLAB R2019b. To validate the idea in this work, three other ensemble learning algorithms were investigated to show the best performed. The result shows that the proposed optimized scheme (AdaBoostM2) outperformed other state-of-the-art algorithms as well as related works with an accuracy of 99:6%.

Optimized Ensemble Learning Algorithm for Hidden Malicious Traffic Detection in VANET

Goodness Oluchi Anyanwu,Jae-Min Lee,Dong-Seong Kim 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.11

The growth in intelligent transport system comes the challenge of monitoring transportation data traffic for a secured and cost-efficient system Securing the system requires the incorporation of the IoT and Artificial Intelligence as security is of primary importance to connected vehicles. For a secured vehicular space, this work proposed an Intrusion Detection Architecture (IDA) to identify traffic from hidden networks. This novel technique has been developed to avoid illegitimate traffic from passing hidden malicious messages across various equipment on VANET. Optimal simulation parameters were selected and the output demonstrates the efficacy of the proposed Ensemble algorithm which achieved a detection accuracy of 99.2% and a Minimum Classification Error of 291.