위임티켓을 이용한 효율적인 대리 서명 기법

서세영,김미혜 충북대학교 컴퓨터정보통신 연구소 2004 컴퓨터정보통신연구 Vol.12 No.1

전자상거래 등 보안을 요구하는 정보보호 시스템 분야에서는 공개키 기반구조(PKI: Public Key Infrastructure)가 폭넓게 사용되고 있다. PKI 도메인들이 더 많이 설립될수록 더 많은 상호 인증을 필요로 하게 된다. 더구나 각 국은 더욱 복잡한 상호 인증을 필요로 하는 많은 인증기관을 가지고 있다. 그러므로 상호 인증을 위한 경로 탐색시 최단시간에 인증 경로를 찾을 수 있는 알고리즘이 필요하다. 본 논문에서는 위임티켓을 이용한 위탁 인증 방식으로 에이전트들과 이동 노드간의 직접적인 인증을 가능하게 하고, 핸드오프시 오버헤드를 최소화 하여 인증시간을 단축하였다. In the field of secure information systems including electronic commercials, public key infrastructure(PKI) is widely used for secure services. The more PKI domains are established, the more needs are required for cross-domain certifications. Furthermore, each country has many certificate authorities(CA) which requires more complex cross certification. We may need a fast algorithm in order to find the possible certification paths. In this paper, we reduced certification time by reducing overhead of handoff and the direct certification between agents and mobile nodes

단백체를 이용한 애기장대 Cytokinin 유도 단백질의 분석

양영실,차준영,네티 엘마와티,정민희,배동원,이창원,손대영 Plant molecular biology and biotechnology research 2005 Plant molecular biology and biotechnology research Vol.2005 No.

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. To better understand the molecular mechanisms of cytokinin action, we identified cytokinin related proteins by a proteomic approach. Proteins extracted from control and trans-zeatin treated Arabidopsis seedlings were separated and analyzed by two dimensional gel analysis. Differentially expressed protein spots were identified with peptide mass fingerprinting based on matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and database searching. We obtained ten up-regulated and one down-regulated proteins upon t-zeatin treatment. The expression of the following proteins was induced; pollen allergen like protein, L-ascorbate peroxidase, tetrapyrrole methylase family protein, SGT1 protein homolog, disease resistance related protein, maternal embryogenesis control protein, paxneb related protein, gluthathione S-transferase and IAA amino acid hydrolase homolog.

신세대 농민공의 사회보장 문제에 관한 소고

박영실 동아대학교 동아시아연구원 2011 동아시아 : 비교와 전망 Vol.10 No.2

중국에서 농민공(農民工)은 개혁개방과 함께 등장하여 현재는 거대한 계층으로 성장한 노동집단이다. 농민공은 사회주의 신 중국 농촌의 건설자이며 국민경제발전에 거대한 공헌을 하였다. 최근에는, 이들 농민공 중에서도 젊은 신세대 농민공 계층이 중국 정부의 큰 관심을 받고 있다. 신세대 농민공은 제1세대 농민공에 비한다면 도시 주민에 더 가깝다. 그들의 생활방식 및 가치관은 제1세대 농민공과 비교하여 상당한 차이를 보이는데, 도시 생활을 동경하며 도시에서 더 많은 발전 기회를 얻고자 한다. 그러나 도농이원화체제로 인해 신세대 농민공들은 농민의 신분으로서 도시 주민들과 같은 사회보장권익을 향유할 수 없다. 신세대 농민공은 중국 사회 발전에 있어 중요한 원동력이다. 따라서 그들의 사회적 권익은 더욱더 보호 받아야 한다. 본문은 사회 현실에 입각하여, 신세대 농민공의 특징 및 시민화 과정에서의 사회 보장 결핍으로 인한 권익 침해 원인을 분석 연구하고 사회 보장의 필요성을 살펴보고 실행 가능한 해결책을 제시하여 보고자 한다. In China, peasant migrants are labor groups which grew as a huge class with the appearance of reform and market opening. These peasant migrants have built a new socialist Chinese farming area, and also an important driving force of constructing urban areas, greatly contributing to Chinese national economic development. In recent years, the Chinese government is putting great focus on new generation migrant wokers among the total peasant migrants. Compared to the 1st generation peasant migrants, these new generation migrant wokers are close to urban residents. Their life styles and values are greatly different from those of the 1st generation's, aspire urban life, and want to seize more developing opportunities in the city. However, due to town and village separation system, new generation migrant wokers are in fact farmers, and cannot enjoy the same social security rights as the urban citizens do. The new generation migrant wokers should enjoy more social security rights as the main driver of China's social development. In this regard, this thesis considers the current status and its reasons why new generation peasant migrants lag far behind in terms of social security rights during the citizenship process. In addition, this thesis suggests feasible solutions by reviewing the necessity of the social security, As the main force of city consruction, new generation migrant workers have also played Connecting roles in their family. New Generation Migrant Wokers bring more and more social problems with their coming. Therefore, how to protect Generation Migrant Wokers social security rights is worth to be discussed and solved. Only in this way, the social stability will be kept.

퉁퉁마디로부터 색소체 외막 단백질 유전자의 분리 및 발현분석

네티 엘마와티,차준영,양영실,정민희,신동진,이병현,이곤호,손대영 Plant molecular biology and biotechnology research 2004 Plant molecular biology and biotechnology research Vol.2004 No.-

Complementary DNA encoding chloroplast outer envelope membrane protein (OEP) from the halophyte Salicornia herbacea has been cloned and sequenced. The full length cDNA is 596 bp and encodes a polypeptide of 91 amino acid residues with a molecular mass of 8.9 kDa. The expression level of ShOEP increased by salt, drought and ABA treatments. ShOEP expression was largely induced in roots and shoots by high salts. The biological function of ShOEP was examined by yeast complementation. ShOEP can suppress Na+ sensitivity of yeast mutant (cnbΔ) in the presence of salt. These results suggest that ShOEP is a salt inducible gene and may have functions in the regulation of plant salt stress.

Illumina-based analysis of bacterial diversity related to halophytes Salicornia europaea and Sueada aralocaspica

Ying-wu Shi,Kai Lou,Chun Li,Lei Wang,Zhen-yong Zhao,Shuai Zhao,Chang-yan Tian 한국미생물학회 2015 The journal of microbiology Vol.53 No.10

We used Illumina-based 16S rRNA V3 amplicon pyrosequencing to investigate the community structure of soil bacteria from the rhizosphere surrounding Salicornia europaea, and endophytic bacteria living in Salicornia europaea plants and Sueada aralocaspica seeds growing at the Fukang Desert Ecosystem Observation and Experimental Station (FDEOES) in Xinjiang Province, China, using an Illumina genome analyzer. A total of 89.23 M effective sequences of the 16S rRNA gene V3 region were obtained from the two halophyte species. These sequences revealed a number of operational taxonomic units (OTUs) in the halophytes. There were between 22–2,206 OTUs in the halophyte plant sample, at the 3% cutoff level, and a sequencing depth of 30,000 sequences. We identified 25 different phyla, 39 classes and 141 genera from the resulting 134,435 sequences. The most dominant phylum in all the samples was Proteobacteria (41.61%–99.26%; average, 43.30%). The other large phyla were Firmicutes (0%– 7.19%; average, 1.15%), Bacteroidetes (0%–1.64%; average, 0.44%) and Actinobacteria (0%–0.46%; average, 0.24%). This result suggested that the diversity of bacteria is abundant in the rhizosphere soil, while the diversity of bacteria was poor within Salicornia europaea plant samples. To the extent of our knowledge, this study is the first to characterize and compare the endophytic bacteria found within different halophytic plant species roots using PCR-based Illumina pyrosequencing method.

Probabilistic quantum relay communication in the noisy channel with analogous space-time code

Shi, Jinjing,Shi, Ronghua,Guo, Ying,Peng, Xiaoqi,Lee, Moon Ho Springer-Verlag 2013 Quantum information processing Vol.12 No.5

Moth-Flame Optimization-Based Maximum Power Point Tracking for Photovoltaic Systems Under Partial Shading Conditions

Shi, Ji-Ying,Zhang, Deng-Yu,Xue, Fei,Li, Ya-Jing,Qiao, Wen,Yang, Wen-Jing,Xu, Yi-Ming,Yang, Ting The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

Combining Model-based and Heuristic Techniques for Fast Tracking the Global Maximum Power Point of a Photovoltaic String

Shi, Ji-Ying,Xue, Fei,Ling, Le-Tao,Li, Xiao-Fei,Qin, Zi-Jian,Li, Ya-Jing,Yang, Ting The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Under partial shading conditions (PSCs), multiple maximums may be exhibited on the P-U curve of string inverter photovoltaic (PV) systems. Under such conditions, heuristic methods are invalid for extracting a global maximum power point (GMPP); intelligent algorithms are time-consuming; and model-based methods are complex and costly. To overcome these shortcomings, a novel hybrid MPPT (MPF-IP&O) based on a model-based peak forecasting (MPF) method and an improved perturbation and observation (IP&O) method is proposed. The MPF considers the influence of temperature and does not require solar radiation measurements. In addition, it can forecast all of the peak values of the PV string without complex computation under PSCs, and it can determine the candidate GMPP after a comparison. Hence, the MPF narrows the searching range tremendously and accelerates the convergence to the GMPP. Additionally, the IP&O with a successive approximation strategy searches for the real GMPP in the neighborhood of the candidate one, which can significantly enhance the tracking efficiency. Finally, simulation and experiment results show that the proposed method has a higher tracking speed and accuracy than the perturbation and observation (P&O) and particle swarm optimization (PSO) methods under PSCs.

Dual-Algorithm Maximum Power Point Tracking Control Method for Photovoltaic Systems based on Grey Wolf Optimization and Golden-Section Optimization

Shi, Ji-Ying,Zhang, Deng-Yu,Ling, Le-Tao,Xue, Fei,Li, Ya-Jing,Qin, Zi-Jian,Yang, Ting The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper presents a dual-algorithm search method (GWO-GSO) combining grey wolf optimization (GWO) and golden-section optimization (GSO) to realize maximum power point tracking (MPPT) for photovoltaic (PV) systems. First, a modified grey wolf optimization (MGWO) is activated for the global search. In conventional GWO, wolf leaders possess the same impact on decision-making. In this paper, the decision weights of wolf leaders are automatically adjusted with hunting progression, which is conducive to accelerating hunting. At the later stage, the algorithm is switched to GSO for the local search, which play a critical role in avoiding unnecessary search and reducing the tracking time. Additionally, a novel restart judgment based on the quasi-slope of the power-voltage curve is introduced to enhance the reliability of MPPT systems. Simulation and experiment results demonstrate that the proposed algorithm can track the global maximum power point (MPP) swiftly and reliably with higher accuracy under various conditions.

Stress Dependence of Thermal Stability of Nickel Silicide forNano MOSFETs

Ying-Ying Zhang,Won-Jae Lee,Zhun Zhong,Shi-Guang Li,Soon-Yen Jung,이가원,왕진석,이희덕,Sung-Kyu Lim 한국전기전자재료학회 2007 Transactions on Electrical and Electronic Material Vol.8 No.3

Dependence of the thermal stability of nickel silicide on the film stress of inter layer dielectric (ILD) layer has been investigated in this study and silicon nitride (Si3N4) layer is used as an ILD layer. Nickel silicide was formed with a one-step rapid thermal process at 500 oC for 30 sec. 2000 Å thick Si3N4 layer was deposited using plasma enhanced chemical vapor deposition after the formation of Ni silicide and its stress was split from compressive stress to tensile stress by controlling the power of power sources. Stress level of each stress type was also split for thorough analysis. It is found that the thermal stability of nickel silicide strongly depends on the stress type as well as the stress level induced by the Si3N4 layer. In the case of high compressive stress, silicide agglomeration and its phase transformation from the low-resistivity nickel mono-silicide to the high-resistivity nickel di-silicide are retarded, and hence the thermal stability is obviously improved a lot. However, in the case of high tensile stress, the thermal stability shows the worst case among the stressed cases.