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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

Determining node duty cycle using Q-learning and linear regression for WSN

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Frontiers of Computer Science 2021年第1期15卷 17-23页

作者： han Yao HUANG kyung Tae kim Hee Yong YOUN College of Software Sungkyunkwan UniversitySuwon 440-746Korea

Wireless sensor network(WSN)is effective for monitoring the target environment,which consists of a large number of sensor nodes of limited *** efficient medium access control(MAC)protocol is thus imperative to maximize the energy efficiency and performance of *** most existing MAC protocols are based on the scheduling of sleep and active period of the nodes,and do not consider the relationship between the load condition and *** this paper a novel scheme is proposed to properly determine the duty cycle of the WSN nodes according to the load,which employs the Q-leaming technique and function approximation with linear *** allows low-latency energy-efficient scheduling for a wide range of traffic conditions,and effectively overcomes the limitation of Q-learning with the problem of continuous state-action ***3 simulation reveals that the proposed scheme significantly improves the throughput,latency,and energy efficiency compared to the existing fully active scheme and S-MAC.

关键词： wireless sensor network media access control duty-cycle scheduling Q-leaming linear regression

Fatigue strength evaluation of self-piercing riveted joints of AZ31 Mg alloy and cold-rolled steel sheets

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Journal of Magnesium and Alloys 2020年第1期8卷 241-251页

作者： Se-Hyung Kang Dong-Woon han Ho-kyung kim Graduate School Seoul National University of Science and TechnologySeoul01811South Korea Department of Mechanical and Automotive Engineering Seoul National University of Science and TechnologySeoul01811 South Korea

The application of magnesium alloys to automobiles is increasing due to their superior specific strength and specific *** this study,an upper sheet of AZ31 magnesium alloy and a lower sheet of cold-rolled steel were joined by self-piercing riveting(SPR),a method commonly used to join automotive panels.A cross-shaped specimen was fabricated with a punching force of 35 kN,which exhibited the best joint strength for the SPR joint specimen *** and fatigue strengths were evaluated using cross-shaped specimens at loading angles of 0°,45°,and 90°.The load amplitude corresponding to the fatigue endurance limit was assumed to be at 106 cycles,and the fatigue ratios(=fatigue endurance limit/static strength)at the loading angles of 0°,45°,and 90°are 22%,13%,and 9%,*** all three loading angle specimens,fatigue cracks initiated at the triple point where the rivet shank,the upper sheet and the lower sheet are in contact with each other,with the cracks propagating through the thickness of the upper sheet and ultimately leading to *** fatigue lifetimes were evaluated through the von-Mises stress,maximum principal stress,and equivalent stress intensity *** was found that the fatigue lifetimes could be evaluated most appropriately through the maximum principal stress.

关键词： Self-piercing riveting Magnesium alloy Fatigue strength Maximum principal stress Fatigue lifetime

Morphology Control of Bi2S3 Nanostructures and the Formation Mechanism

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Chinese Journal of Chemistry 2013年第6期31卷 752-756页

作者： HeeJin kim Ji-eun Park kyung kim Mi-kyung han Sung-Jin kim Wooyoung Lee Department of Materials Science and Engineering Yonsei University Seou1120- 749 Korea Department of Chemistry and Nano Science Ewha Womans University Seoul 120-750 Korea

Bismuthinite （Bi2S3）nanostructures were prepared by a hydrothermal method with sodium ethylenediamine- tetraacetate （EDTA-Na2）. The morphology of Bi2S3 nanostructures was changed from a nanorod to a nanoplate by presence of the EDTA-Na2. The altered morphology was caused by the capping effect of EDTA-Na2 with Bi3＋ ions, which induces the suboptimal growth direction due to partially blocking the preferential orientation direction. When the EDTA-Na2/Bi3＋ molar ratio= 1, the growth of Bi2S3 nanostructures was not allowed due to the chelating effect of EDTA-Na2. The obtained Bi2S3 nanorods, stacked nanorods, nanoplates and nanoparticles were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron mi- croscopy （HRTEM） and selected area electron diffraction （SAED） pattern. A possible formation mechanism of these morphologies was proposed. The successful synthesis of various morphologies of nanostructured Bi2S3 may open up new possibilities for thermoelectric, electronic and optoelectronic uses of nanodevices based on Bi2S3 nanostructure.

关键词： bismuth sulfide (Bi2S3) hydrothermal nanorod nanoplate thermoelectric material

A GIS-Based Framework for Real-Time Debris-Flow Hazard Assessment for Expressways in Korea

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International Journal of Disaster Risk Science 2016年第3期7卷 293-311页

作者： han-Saem kim Choong-Ki Chung Sang-Rae kim kyung-Suk kim Earthquake Research Center Korea Institute of Geoscience and Mineral Resources Department of Civil and Environmental Engineering Seoul National University Department of Civil and Environmental Engineering Northwestern University Expressway and Transportation Research Institute Korea Expressway Corporation

Debris flows caused by heavy rainfall in mountain areas near expressways lead to severe social and economic losses and sometimes result in ***, the development of a real-time system for debris-flow hazard assessment is necessary to provide preliminary information for rapid decision making about evacuations or restoration measures, as well as to prevent secondary disasters caused by debris flows. Recently,various map-based approaches have been proposed using multi-attribute criteria and assessment methods for debrisflow susceptibilities. For the macrozonation of debris-flow hazard at a national scale, a simplified method such as the Korea Expressway Corporation(KEC) debris-flow hazard assessment method can be applied for systematic analysis based on geographic information systems(GIS) and monitoring networks. In this study, a GIS-based framework of real-time debris-flow hazard assessment for expressway sections is proposed based on the KEC debris-flow hazard assessment method. First, the KEC-based method was standardized in a systematic fashion using Arc GIS,enabling the objective and quantitative acquisition of various attribute datasets. The quantification of rainfall criteria also was considered. A safety management system for debris-flow hazard was developed based on the GIS platform. Finally, the method was applied and verified on three expressway sections in Korea. The grading standard for each individual influencing attribute was subsequently modified to more accurately assess the debris-flow hazards.

关键词： Debris-flow hazard Expressway management GIS Korea Real-time hazard assessment

Evaluation of the safety of hair essence containing 0.05% purified bee venom on the skin and eyes of rabbits

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Journal of Traditional Chinese Medicine 2020年第1期40卷 67-72页

作者： Mi kyung Lim Eun Hye han Sang Ho Lee Jee Hee kim R&D Center KoreaeundanGyeonggi-do 13207Republic of Korea

OBJECTIVE:To investigate the safety of hair essence containing 0.05%purified bee venom(HE-PBV)on the skin and eyes of New Zealand White ***:HE-PBV which contained 0.05%PBV,purified water,and glycerin,was used as the test *** skin-irritation test(SIT)and eye-irritation test(EIT)were conducted according to the Draize *** the SIT,HE-PBV(0.5 m L)dropped gauze was attached both intact and abraded skin for 24 *** other side of the skin was used as *** 24 and 72 h,the treatment site was observed and scored according to evaluation criteria for skin *** the EIT,the rabbits were divided into two groups:eye-washed(three rabbits)and non-eye-washed(six rabbits).HE-PBV(0.1 m L)was squirted into the right eye of *** left eye was untreated and used as a ***,20-30-s later,the eyes of rabbits in the eye-washed group were washed with^50 m L of physiologic(0.9%)salt ***,1,2,3,4 and 7 d after the start of the EIT,the eyes and behavior of the rabbits were *** degree of eye irritation elicited by HE-PBV was determined in three steps and then the criteria of the classification of eye-irritation ***:The SIT revealed erythema and edema at the site of HE-PBV *** 72 h,the body weight of rabbits was reduced slightly,but other symptoms(except erythema and edema)were not *** Primary Irritation Index score was0.6,and HE-PBV was deemed to be a slight *** EIT did not show mortality or body-weight fluctuation,but hyperemic conjunctiva and eyelid closure were noted after HE-PBV *** for these results,the score for the ophthalmic response on days 1,2,3,4 and 7 was 0,and HE-PBV was deemed to be a ***:These data suggest that HE-PBV did not elicit eye irritation,but was a slight irritant to the skin of rabbits;the latter slight would have been due to the excipients used in manufacture of the hair essence because PBV has been shown to be safe.

关键词： Alopecia Bee Venoms Hair essence Skin irritancy tests Eye irritancy tests Complementary therapies

Bile-derived circulating extracellular mi R-30d-5p and mi R-92a-3p as potential biomarkers for cholangiocarcinoma

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Hepatobiliary & Pancreatic Diseases International 2020年第1期19卷 41-50页

作者： Hye Sook han Mi Jin kim Joung-Ho han Jieun Yun Hee kyung kim Yaewon Yang Ki Bae kim Seon Mee Park Department of Internal Medicine Chungbuk National University HospitalCheongju 28644Korea Departments of Internal Medicine Chungbuk National University College of MedicineCheongju 28644Korea Department of Pharmaceutical Engineering College of Science EngineeringCheongju UniversityCheongju 28644Korea

Background: Cholangiocarcinoma (CCA) is from cholangiocytes, and therefore bile is a potentially rich source of biomarkers for CCA. The aim of the study was to identify and validate microRNAs (miRNAs) in bile samples that are differentially expressed between benign biliary disease (BBD) and CCA. Methods: Bile samples from 106 patients with obstructive biliary disease were allocated consecutively to a discovery set (10 patients with BBD and 11 with CCA) and then a validation set (48 patients with BBD and 37 with CCA). An miRNA microarray platform was used to screen 1209 miRNAs in the discovery set. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to validate the pro ling results in the discovery and validation sets. In addition, the levels of carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) were determined from patient serum samples. Results: Microarray pro ling showed that miR-30d-5p and miR-92a-3p were signi cantly upregulated in bile from the CCA group compared with those from the BBD group. qRT-PCR results indicated that the expression levels of miR-30d-5p and of miR-92a-3p were signi cantly upregulated in the CCA group compared to the BBD group, validating the miRNA microarray results. Pathway analysis suggested that putative target genes of miR-30d-5p and of miR-92a-3p were involved in CCA-associated signalling path- ways, such as Hippo, Wnt, p53, MAPK, and EGFR. Receiver operating curve analysis revealed that the areas under the curve for bile miR-30d-5p, miR-92a-3p, serum CA19-9, and CEA were 0.730, 0.652, 0.675, and 0.603, respectively, and bile miR-30d-5p showed the best diagnostic performance with a sensitivity of 81.1% and a speci city of 60.5%. Conclusions: The levels of extracellular miR-30d-5p and miR-92a-3p in bile were signi cantly higher in patients with CCA than those in patients with BBD. Bile-derived circulating extracellular miR-30d-5p and miR-92a-3p are potential biomarkers for discr

关键词： Bile Biomarkers Cholangiocarcinoma MicroRNA

Germinant ZnO nanorods as a charge-selective layer in organic solar cells

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Journal of Materials Science & Technology 2020年第20期52卷 89-94页

作者： Kunsik An Jaehoon kim Mohammad Afsar Uddin Seunghyun Rhee Hyeok kim kyung-Tae Kang han Young Woo Changhee Lee Department of Electrical and Computer Engineering Seoul National UniversitySeoul 08826Republic of Korea Micro/Nano Process Group Korea Institute of Industrial Technology(KITECH)Sangnok-guAnsan-si 15588Republic of Korea Department of Chemistry College of ScienceKorea UniversitySeoul 02841Republic of Korea Department of Electrical Engineering Engineering Research Institute(ERI)Gyeongsang National UniversityJinju 52828Republic of Korea

A facile method was introduced and demonstrated to synthesize zinc oxide(ZnO) nanorods(NRs) as an electron transporting layer(ETL) for organic solar cells(OSCs).Hydrothermal synthesis of the NRs showed a constant growth rate of 5.5 nm min-1 from germination to sub-micrometer *** properties were characterized using scanning electron microscopy(SEM),transmission electron microscopy(TEM),absorption spectrophotometry and so *** on these measurements,the germinant growth mechanism and its corresponding orientation characteristics were *** an ETL of the OSCs,ZnO NRs enhance the charge extraction from the active layer due to their increased interfacial surface area,but there is an optimal length because of the shunt path formation and UV absorption of long ZnO *** a re sult,the OSC with the ZnO NRs as ETL shows power conversion efficiency(PCE) up to 6.2%.The J-V characteristics and incident photon-to-current conversion efficiency(IPCE) measurement also reveal that the efficiency enhancement is an assembly of individual results from optical,physical and electrical characteristic of the ZnO NRs.

关键词： ZnO nanorods Solar cells Self-assembly Oriented growth mechanism Hydrothermal synthesis

Identification of differentially expressed miRNAs associated with chronic kidney disease-mineral bone disorder

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Frontiers of Medicine 2017年第3期11卷 378-385页

作者： kyung Im kim Sohyun Jeong Nayoung han Jung Mi Oh Kook-Hwan Oh In-Wha kim College of Pharmacy Korea University Sejong 30019 Republic of Korea College of Pharmacy and Research Institute of Pharmaceutical Sciences -Seoul National University Seoui 08826 Republic of Korea Divisionof-Nephrology Department of Internai Medicine Seoul National University Hospital Seoul 03080 Republic of Korea

The purpose of this study is to characterize a meta-signature of differentially expressed mRNA in chronic kidney disease （CKD） to predict putative microRNA （miRNA） in CKD-mineral bone disorder （CKD- MBD） and confirm the changes in these genes and miRNA expression under uremic conditions by using a cell culture system. PubMed searches using MeSH terms and keywords related to CKD, uremia, and mRNA arrays were conducted. Through a computational analysis, a meta-signature that characterizes the significant intersection of differentially expressed mRNA and expected miRNAs associated with CKD-MBD was determined. Additionally, changes in gene and miRNA expressions under uremic conditions were confirmed with human Saos-2 osteoblast-like cells. A statistically significant mRNA meta-signature of upregulated and downregulated mRNA levels was identified. Furthermore, miRNA expression profiles were inferred, and computational anaIyses were performed with the imputed mieroRNA regulation based on weighted ranked expression and putative microRNA targets （IMRE） method to identify miRNAs associated with CKD occurrence. TLR4 and miR-146b levels were significantly associated with CKD-MBD. TLR4 levels were significantly downregulated, whereas pri- miR-146b and miR-146b were upregulated in the presence of uremic toxins in human Saos-2 osteoblast-like cells. Differentially expressed miRNAs associated with CKD-MBD were identified through a computational analysis, and changes in gene and miRNA expressions were confirmed with an in vitro cell culture system.

关键词： chronic kidney disease microRNA mineral bone disorder uremia