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Efficient and secure source authentication scheme for multicast user authentication

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Journal of Central South University 2013年第10期20卷 2741-2746页

作者： JEONG Yoon-su lee Sang-hyuk SHIN seung-soo Department of Information Communication Engineering Mokwon University Department of Electrical and Electronic Engineering Xi’an Jiaotong-Liverpool University Department of Information Security Tongmyong University

Multicast technology application has been widely utilized in broadband internet. Source authentication is one of the most needs for many multicast applications transferring real-time information such as stream video and online news. Because multicast current services provided to the group members are changed dynamically, data transferring by a group member is not used by the recipient. In order to verify the identity of the sender who sent the packet and to make sure that the data have not been tampered, an optimized source authentication scheme has been proposed to transfer the authentication information not to the next-door packet. The proposed method for multiple packets authenticates the source with a limited number of electronic signatures. The proposed method can reduce overhead compared to the method by adding a digital signature for every packet. In addition, by sending the generated electronic signature to the first packet and the last packet, it prevents the loss of consecutive packets, as well as a source authentication can be provided in real-time services.

关键词： multicast packet source authentication broadband Internet

Horizontal distribution of Changjiang Diluted Water in summer inferred from total suspended sediment in the Yellow Sea and East China Sea

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Acta Oceanologica Sinica 2015年第12期34卷 44-50页

作者： lee Dong-Kyu KWON Jae-Il SON seung Hyun Pusan National University Coastal Disaster Research Center Korea Institute of Ocean Science and Technology China-Korea Joint Ocean Research Center Cooperative Institute for Research in the Atmosphere Colorado State University

During the summer in the Yellow Sea and East China Sea, the resuspension of the bottom sediment is obstructed by strong stratification and, as a result, the concentration of total suspended sediment（TSS） can be used as an excellent tracer for Changjiang Diluted Water（CDW）. To analyze the spatial and temporal variations of the CDW distribution, the monthly mean TSS from Moderate Resolution Imaging Spectroradiometer（MODIS） ocean color data are constructed and are converted to salinity using the relationship between salinity observed from AQUARIUS and TSS. The process produces the detailed horizontal distribution of salinity with very high resolution（1 km）. From monthly mean salinity map from 2002 to 2012 in July and August, the expansion patterns of CDW are analyzed. The southerly wind in July and southeasterly wind in August transport the CDW eastward and northeastward, respectively. It is found that the yearly variation of the expansion of CDW toward the southern sea area of Korea is mostly due to the variation of southerly wind and the fluctuations of fresh water discharge into the Changjiang estuary show relatively little impact on the eastward extend of CDW. When 11-year mean（from2002 to 2012） salinity map in August is compared with World Ocean Atlas 2013, it is revealed that wind in August strengthened six times from 1994 and it causes the expansion of CDW extended 150 km further eastward.

关键词： Yellow and East China Seas Changjiang diluted water total suspended sediment MODIS

Comparison of cytotoxicity and wound healing effect of carboxymethylcellulose and hyaluronic acid on human corneal epithelial cells

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 215-221页

作者： Jong Soo lee seung Uk lee Cheng-Ye Che Ji-Eun lee Department of Ophthalmology School of MedicinePusan National University Biomedical Research Institute Pusan National University Hospital Department of Ophthalmology School of Medicine Kosin University Department of Ophthalmology the Affiliated Hospital of Medical College Qingdao University Research Institute for Convergence of Biomedical Science and Technology Pusan National University Yangsan Hospital

AIM: To investigate the cytotoxic effect on human corneal epithelial cells(HCECs) and the ability to faciliate corneal epithelial wound healing of carboxymethylcellulose(CMC) and hyaluronic acid(HA).METHODS: HCECs were exposed to 0.5% CMC(Refresh plus, Allergan, Irvine, California, USA) and 0.1% and 0.3%HA(Kynex , Alcon, Seoul, Korea, and Hyalein mini,Santen, Osaka, Japan) for the period of 30 min, and 4, 12,and 24 h. Methyl thiazolyl tetrazoiun(MTT)-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase(LDH) leakage assay to assess the cytotoxicity. apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. The wound widths were measured 24 h after confluent HCECs were scratch ***: The inhibitory effect of human corneal epithelial proliferation and cytotoxicity showed the time-dependent response but no significant effect. Apoptosis developed in flow cytometry and apoptotic cells weredemonstrated in fluorescent micrograph. The damaged HCECs were detached from the bottom of the dish and showed the well-developed vacuole formations. Both CMC and HA stimulated reepithehlialization of HCECs scratched, which were more observed in ***: CMC and HA, used in artificial tear formulation, could be utilized without any significant toxic effect on HCECs. Both significantly stimulated HCEC reepithelialization of corneal wounds.

关键词： carboxymethylcellulose corneal wound healing human corneal epithelial cells hyaluronic acid cytotoxicity

Design and use of group-specific primers and probes for real-time quantitative PCR

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Frontiers of Environmental Science & Engineering 2011年第1期5卷 28-39页

作者： Juntaek LIM seung Gu SHIN seungyong lee Seokhwan HWANG School of Environmental Science and Engineering Pohang University of Science and TechnologyPohangGyungbuk 790-784The Republic of Korea

Real-time quantitative polymerase chain reaction(qPCR)has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil,water,sediments,and *** qPCR is a very useful technique for nucleic acid quantification,accurately quantifying the target microbial group strongly depends on the quality of the primer and probe *** aspects of conducting qPCR assays have become increasingly routine and automated;however,one of the most important aspects,designing and selecting primer and probe sets,is often a somewhat arcane *** many cases,failed or non-specific amplification can be attributed to improperly designed primer-probe *** paper is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR *** demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic nutrient removal *** assays using group-specific primers and probes designed with this method,have been used to successfully quantify 16S ribosomal Ribonucleic Acid(16S rRNA)gene copy numbers from target methanogenic and ammoniaoxidizing bacteria in various laboratory-and full-scale biologic *** with a good command of primer and probe design can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes.

关键词： absolute quantification design guideline primer probe real-time quantitative polymerase chain reaction(qPCR)

Three-dimensional porous graphene-metal oxide composite microspheres： Preparation and application in Li-ion batteries

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Nano Research 2015年第5期8卷 1584-1594页

作者： seung Ho Choi Jung-Kul lee Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea Department of Chemical Engineering Konkuk University 1 Hwayang-Dong Gwangjin-Gu Seou1143-701 Republic of Korea

The use of new three-dimensional （3D） porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries （LIBs） is first introduced here. 3D graphene microspheres are aggregates of individual hollow graphene nanospheres composed of graphene sheets. Metal oxide nanocrystals are uniformly distributed over the graphene surface of the microspheres. The 3D porous graphene-SnO2 microspheres are selected as the first target material for investigation because of their superior electrochemical properties. The 3D porous graphene-SnO2 and graphene microspheres and bare SnO2 powders deliver discharge capacities of 1,009, 196, and 52 mAh·g^-1, respectively, after 500 cycles at a current density of 2 A·g^-1 .The 3D porous graphene-SnO2 microspheres exhibit uniquely low charge transfer resistances and high Li-ion diffusivities before and after cycling.

关键词： graphene metal oxide nanostructures electrode material batteries

Effects of an Urban Park and Residential Area on the Atmospheric CO_2 Concentration and Flux in Seoul,Korea

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Advances in Atmospheric Sciences 2013年第2期30卷 503-514页

作者： Moon-Soo PARK seung Jin JOO Chang Seok lee Center for Atmospheric and Environmental Modeling Seoul 151 919Korea Life and Environmental Engineering Seoul Women's UniversitySeoul 139 774Korea

The CO2 concentrations and fluxes over an urban forest site （Namsan） and an urban residential region （Boramae） in Seoul, Korea, during the non-growing season （2 4 March 2011）, the growing season （10-12 June 2011）, and the late-growing season （22-24 September 2011） were analyzed. The CO2 concentrations of two sites showed nearly the same diurnal variation, with a maximum value occurring during the night and a minimum value occurring during daytime, as well as the same seasonal variation, with a maximum value during the non-growing season （early spring） and a minimum value during the growing season （summer）. The CO2 flux over the urban forest did not show any typical diurnal variation during the non-growing season, but did show diurnal variation with a small positive value during the night and a large negative value during daytime in the growing and late-growing seasons due to photosynthesis in the urban forest. The CO2 flux over the urban residential region showed a positive daily mean value for all periods, with large values during the non-growing season and small values during the growing season, and it also showed diurnal variation with two maxima at 0600-1000 LST and 1800-2400 LST, and two minima at 0300-0600 LST and 1100-1500 LST, and was strongly correlated with the use of liquefied natural gas for cooking and heating by surrounding houses.

关键词： C02 concentration C02 flux Seoul urban forest urban residential region

Influence of the wastewater composition on denitrification and biological P-removal in the S-DN-P process: (c) Dissolved and undissolved substrates

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Journal of Environmental Sciences 2009年第8期21卷 1074-1079页

作者： Hee-Jeong Choi Chul-Ho Choi seung-Mok lee Diwakar Tiwari Department of Environmental Engineering Kwandong University Department of Chemistry School of Physical Sciences Mizoram University

The denitdfication and P-removal in the sorption-denitrification-P-removal （S-DN-P） process were carded out under various wastewater compositions. It is noted that P-removal largely depends on the wastewater composition as well to the quantity of the substrates present in wastewater fraction. Three different wastewater fractions are obtained as： raw wastewater, dissolved wastewater （obtained with filtration using 0.45 μm filter）, and undissolved wastewater （i.e., infiltrate obtained by above filtration）. The ratio of P-release/CODtotal-consumption clearly inferred that undissolved wastewater possess very low value i.e., 0.0008 followed by raw wastewater 0.008 and dissolved wastewater 0.03. When this ratio was nearby 0.01, enhanced P-removal was observed. Moreover, the ratio of P-uptake to NO3^--N decomposition for raw wastewater was two times for dissolved wastewater. Interestingly, it was observed that the P-removal and denitrification depend not only on the dissolved substrates but also the undissolved substrates present in the wastewater. The result of the P-removal obtained with this S-DN-P process did not show a big difference of 36%, 34% and 30%, respectively, for raw, dissolved and undissolved wastewater.

关键词： denitrification polyhydroxybutyrate sequencing batch biofilm reactor sorption denitrification P-removals

CaCO_3 film synthesis from ladle furnace slag: morphological change, new material properties, and Ca extraction efficiency

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1447-1456页

作者： seung-Woo lee Yong-Jae Kim Jun-Hwan Bang Soochun Chae Center for carbon mineralization Korea Institute of Geosciences and Mineral Resources Frontier in extreme physics Korea Research Institute of Standards and Science

A rapidly air-cooled ladle furnace slag(RA-LFS), which is a type of steelmaking slag discharged from a steel mill, was used to synthesize CaCO_3 film. The CaCO_3 film with 35 cm^2 of surface area was synthesized under atmospheric conditions, and the surface morphology of the CaCO_3 films was changed by using additives(CaCl_2 and ethylene glycol). Especially, the addition of CaCl_2 changed the surface morphology of CaCO_3 film with pore and induced new material properties, such as water adsorption. The(012) face of CaCO_3 film(calcite) was rapidly decreased by the addition of CaCl_2. The major components of RA-LFS were calcium(type of CaO, 53.9 wt%) and aluminum(type of Al_2 O_3, 37.9 wt%), and the major crystal phases of RA-LFS were C_3 S, C_(12) A_7, and C_3 A. The calcium extraction efficiency of RA-LFS was significantly increased after the CaCO_3 film synthesis. The material properties(hardness and elastic modulus) and the thermal characteristics of the CaCO_3 films were analyzed by nano-indentation and thermogravimetry–differential thermal analysis. The synthesized CaCO_3 films from RA-LFS and Ca(OH)_2(reagent) showed similarities in terms of their material properties and the decomposition temperature.

关键词： carbon dioxide ladle furnace slag carbonation calcium carbonate film calcium efficiency

Absorption-Dominant mmWave EMI Shielding Films with Ultralow Reflection using Ferromagnetic Resonance Frequency Tunable M-Type Ferrites

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Nano-Micro Letters 2023年第6期15卷 1-23页

作者： Horim lee seung Han Ryu Suk Jin Kwon Jae Ryung Choi Sang‑bok lee Byeongjin Park Composites Research Division Korea Institute of Materials Science797 ChangwondaeroSeongsan‑GuChangwonGyeongsangnam‑Do 51508Republic of Korea

Although there is a high demand for absorption-dominant electromagnetic interference(EMI) shielding materials for 5G millimeter-wave(mmWave) frequencies, most current shielding materials are based on reflection-dominant conductive materials. While there are few absorption-dominant shielding materials proposed with magnetic materials, their working frequencies are usually limited to under 30 GHz. In this study, a novel multi-band absorption-dominant EMI shielding film with M-type strontium ferrites and a conductive grid is proposed. This film shows ultralow EMI reflection of less than 5% in multiple mmWave frequency bands with sub-millimeter thicknesses, while shielding more than 99.9% of EMI. The ultralow reflection frequency bands are controllable by tuning the ferromagnetic resonance frequency of M-type strontium ferrites and composite layer geometries. Two examples of shielding films with ultralow reflection frequencies, one for 39 and 52 GHz 5G telecommunication bands and the other for 60 and 77 GHz autonomous radar bands, are presented. The remarkably low reflectance and thinness of the proposed films provide an important advancement toward the commercialization of EMI shielding materials for 5G mmWave applications.

关键词： 5G communication MmWave EMI shielding M-type ferrites