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Modified analogue forecasting in the hidden Markov frameworkfor meteorological droughts

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Science China(Technological Sciences) 2019年第1期62卷 151-162页

作者： CHEN Si CHUNG GunHui kim Byung Sik kim tae-Woong Department of Civil and Environmental Engineering Hanyang University Department of Civil Engineering Hoseo University Department of Urban Environmental Disaster Prevention Engineering Kangwon National University

An analogue method(AM) is a nonparametric approach that has been applied to predict the future states of a dynamic system by following the evolution of the analogues in the historical archive. In this study, we proposed a hidden Markov model(HMM)framework for a modified analogue forecasting(MAF) approach for meteorological droughts in Korea. The unobservable(hidden) state process in the framework aims to model the underlying drought state, while the observation process was formed from the time series of the standardized precipitation index(SPI) as a drought index. Within the framework, the likelihood estimator was used as the measure of similarity between past SPI analogues and current data. The MAF approach was conducted on the selected analogues to make forecasts at lead times of one and three months. The proposed model was applied to five selected stations in Korea using the SPI data from 1973 to 2016. The forecasting performance of the proposed model was tested during the validation period(2003–2016) using several statistical criteria and it was compared to a persistence-based benchmark model. The results showed significant improvement in the forecasting capacity, and satisfactory performance for numerical SPI forecasting and categorical drought forecasting. The results also suggested that the proposed model was able to provide useful information for determining future drought categories for early drought warning with a lead time of up to three months.

关键词： modified analogue forecasting hidden Markov model meteorological drought standardized precipitation index

Comparative toxicity of silver nanoparticles and silver ions to Escherichia coli

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Journal of Environmental Sciences 2018年第4期30卷 50-60页

作者： Yoojin Choi Hyun-A kim Kyoung-Woong kim Byung-tae Lee Department of Chemical and Biomolecular Engineering (BK21 Plus Program) Korea Advanced Institute of Science and Technology (KAIST) School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology (GIST)

With the increase in silver（Ag）-based products in our lives, it is essential to test the potential toxicity of silver nanoparticles（Ag NPs） and silver ions（Ag ions） on living organisms under various conditions. Here, we investigated the toxicity of Ag NPs with Ag ions to Escherichia coli K-12 strain under various conditions. We observed that both Ag NPs and Ag ions display antibacterial activities, and that Ag ions had higher toxicity to E. coli K-12 strain than Ag NPs under the same concentrations. To understand the toxicity of Ag NPs at a cellular level, reactive oxygen species（ROS） enzymes were detected for use as antioxidant enzymatic biomarkers. We have also studied the toxicity of Ag NPs and Ag ions under various coexistence conditions including： fixed total concentration, with a varied the ratio of Ag NPs to Ag ions; fixed the Ag NPs concentration and then increased the Ag ions concentration; fixed Ag ions concentration and then increasing the Ag NPs *** to Ag NPs and Ag ions clearly had synergistic toxicity; however, decreased toxicity（for a fixed Ag NPs concentration of 5 mg/L, after increasing the Ag ions concentration） to E. coli K-12 strain. Ag NPs and Ag ions in the presence of L-cysteine accelerated the bacterial cell growth rate, thereby reducing the bioavailability of Ag ions released from Ag NPs under the single and coexistence conditions. Further works are needed to consider this potential for Ag NPs and Ag ions toxicity across a range of environmental *** Significance Statement： As silver nanoparticles（Ag NPs）-based products are being broadly used in commercial industries, an ecotoxicological understanding of the Ag NPs being released into the environment should be further considered. Here, we investigate the comparative toxicity of Ag NPs and silver ions（Ag ions） to Escherichia coli K-12 strain, a representative ecotoxicological bioreporter. This study showed that toxicities of Ag NPs and Ag ions to E. coli

关键词： Nanotoxicity Silver nanoparticles Silver ions Coexist condition Escherichia coli

Injection molding of micro patterned PMMA plate

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 148-152页

作者： Yeong-Eun YOO tae-Hoon kim tae-Jin JE Doo-Sun CHOI Chang-Wan kim Sun-Kyung kim Department of Nanomanufacturing Technology KIMM 171 Jang-dong Yusung-gu Daejeon 305-343 Korea Department of Product Design and Manufacturing Seoul National University of Technology

A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 minx213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 ram. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate （PMMA） was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

关键词： micro prism pattern injection molding replication pressure profile temperature profile

PopFlow:a novel flow management scheme for SDN switch of multiple flow tables based on flow popularity

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Frontiers of Computer Science 2020年第6期14卷 111-122页

作者： Cheng WANG Kyung tae kim Hee Yong YOUN College of Electrical and Computer Engineering Sungkyunkwan UniversitySuwon 16419Korea College of Software Sungkyunkwan UniversitySuwon 16419Korea

Pipeline processing is applied to mutiple flow tables(MFT)in the switch of software-defined network(SDN)to increase the throughput of the ***,the processing time of each flow increases as the size or number of flow tables gets *** this paper we propose a novel approach called PopFlow where a table keeping popular flow entries is located up front in the pipeline,and an express path is provided for the flow matching the table.A Markov model is employed for the selection of popular entries considering the match latency and match frequency,and Queuing theory is used to model the flow processing time of the existing MFT-based schemes and the proposed *** simulation reveals that the proposed scheme substantially reduces the flow processing time compared to the existing schemes,and the diference gets more significant as the flow arrival rate increases.

关键词： edge computing SDN pipeline processing PopFlow match frequency and latency markov model-based prediction

q-Bernoulli polynomials and q-umbral calculus

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Science China Mathematics 2014年第9期57卷 1867-1874页

作者： kim Dae San kim tae Kyun Department of Mathematics Sogang University Department of Mathematics Kwangwoon University

In this paper,we investigate some properties of q-Bernoulli polynomials arising from q-umbral *** find a formula for expressing any polynomial as a linear combination of q-Bernoulli polynomials with explicit ***,we es... 详细信息

关键词： q-Bernoulli polynomial q-umbral calculus

3D designed battery-free wireless origami pressure sensor

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Microsystems & Nanoengineering 2022年第6期8卷 35-46页

作者： taeil kim Amirhossein Hassanpoor Kalhori tae-Ho kim Chao Bao Woo Soo kim Additive Manufacturing Laboratory School of Mechatronic Systems EngineeringSimon Fraser UniversitySurrey V3T 0A3 BCCanada

A pressure monitoring structure is a very useful element for a wearable device for health monitoring and sports *** pressure sensors have been studied extensively,battery-free functions working in wireless detection have not been studied ***,we report a 3D-structured origami-based architecture sensor for wireless pressure *** developed an architectured platform for wireless pressure sensing through inductorcapacitor(LC)sensors and a monopole antenna.A personalized smart insole with Miura-ori origami designs has been 3D printed together with conductive 3D printed sensors *** monitoring of resonant frequency and intensity changes of LC sensors have been demonstrated to monitor foot pressure for different *** sensitivity of the wireless pressure sensor is tunable from 15.7 to 2.1 MHz/kPa in the pressure ranges from 0 to 9 kPa and from 10 to 40 kPa,*** proposed wireless pressure-sensing platform can be utilized for various applications such as orthotics,prosthetics,and sports gear.

关键词： battery free utilized

Canonical Foliations of Certain Classes of Almost Contact Metric Structures

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Acta Mathematica Sinica,English Series 2005年第4期21卷 841-846页

作者： tae Wan kim Hong Kyung PAK Department of Mathematics Education Silla UniversityPusan617-736.Korea Department of Computer and Information Security Daegu Haany University

The purpose of this paper is to study the canonical foliations of an almost cosymplectic or almost Kenmotsu manifold M in a unified way. We prove that the canonical foliation F defined by the contact distribution is Riemannian and tangentially almost Kahler of codimension 1 and that F is tangentially Kahler if the manifold M is normal. Furthermore, we show that a semi-invariant submanifold N of such a manifold M admits a canonical foliation FN which is defined by the antiinvariant distribution and a canonical cohomology class c（N） generated by a transversal volume form for FN. In addition, we investigate the conditions when the even-dimensional cohomology classes of N are non-trivial. Finally, we compute the Godbillon Vey class for FN.

关键词： Almost α-cosymplectic manifold Almost cosymplectic manifold Almost Kenmotsu manifold Semi-invariant submanifold

Functional Insights of Plant GSK3-like Kinases： Multi-Taskers in Diverse Cellular Signal Transduction Pathways

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Molecular Plant 2015年第4期8卷 552-565页

作者： Ji-Hyun Youn tae-Wuk kim Department of Life Science College of Natural Sciences Hanyang University Seou1133-791 Korea Naturat Science Institute Hanyang University Seou1133-791 Korea

The physiological importance of GSK3-like kinases in plants emerged when the functional role of plant GSK3-like kinases represented by BIN2 was first elucidated in the brassinosteroid （BR）-regulated signal transduction pathway. While early studies focused more on understanding how GSK3-like kinases regulate BR signaling, recent studies have implicated many novel substrates of GSK3-like kinases that are involved in a variety of cellular processes as well as BR signaling. Plant GSK3-like kinases play diverse roles in physiological and developmental processes such as cell growth, root and stomatal cell development, flower development, xylem differentiation, light response, and stress responses. Here, we review the progress made in recent years in understanding the versatile functions of plant GSK3-like kinases. Based on the relationship between GSK3-like kinases and their newly identified substrates, we discuss the physiological and biochemical relevance of various cellular signaling mediated by GSK3-like kinases in plants.

关键词： GSK3-like kinases brassinosteroids signal transduction pathway Arabidopsis rice

Homeostasis and regulation of autoreactive B cells

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Cellular & Molecular Immunology 2020年第6期17卷 561-569页

作者： Sujin Lee Yeunjung Ko tae Jin kim Department of Immunology Sungkyunkwan University School of MedicineSuwon 16419Republic of Korea

In contrast to the previous belief that autoreactive B cells are eliminated from the normal repertoire of B cells,many autoreactive B cells actually escape clonal deletion and develop into mature B *** autoreactive B cells in healthy individuals perform some beneficial functions in the host and are homeostatically regulated by regulatory T and B cells or other mechanisms to prevent autoimmune *** B-1 cells constitutively produce polyreactive natural antibodies for tissue ***,autoreactive follicular B cells were reported to participate actively in the germinal center ***,the selection and usefulness of autoreactive marginal zone(MZ)B cells found in autoimmune diseases are not well understood,although the repertoire of MZ B-cell receptors(BCRs)is presumed to be biased to detect bacterial *** this review,we discuss the autoreactive B-cell populations among all three major B-cell subsets and their regulation in immune responses and diseases.

关键词： B-cell autoreactivity polyreactivity autoreactive antibody B-cell receptor B-1 lymphocyte autoreactive germinal center autoreactive marginal zone B cell