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Sexual dimorphism and sex-differential migration of Little Buntings(Emberiza pusilla)at an East Asian stopover site

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Avian Research 2022年第1期13卷 87-93页

作者： Sook-young Cho hyun-young Nam Se-young Park chang-Yong Choi Bird Research Center Korea National Park Research InstituteJeonnam58863Republic of Korea Division of Zoology Honam National Institute of Biological ResourcesMokpo58762Republic of Korea School of Biological Sciences College of Natural SciencesSeoul National UniversitySeoul08826Republic of Korea Department of Agriculture Forestry and BioresourcesCollege of Agriculture and Life SciencesSeoul National UniversitySeoul08826Republic of Korea

Sex differences in morphology provide key information for understanding a species'morphological adaptations in relation to the evolution of sexual *** migratory birds,morphological traits have adapted to long-distance travel,and sexual dimorphism is typically related to sex-differential migration *** Buntings(Emberiza pusilla)have one of the longest migrations and are the least dichromatic species among the Emberiza *** this study,we measured sexual size dimorphism and sexual dichromatism of Little Buntings in relation to the spring arrival dates at a stopover site in *** length was the most important predictor for identifying sex;the wings of males were longer than those of *** also had a significantly stronger chestnut color of the head feathers than females,but this color difference was more prominent in the spring than in the *** arrived earlier than females by four *** dates correlated with both size and color,but unlike other bunting species previously studied in the same area,there was no clear sex-differential trend in the relationship between arrival date and morphological *** differences in the degree of sexual dichromatism suggest that chestnut plumage coloration can be used as a social or sexual signal of males in the breeding *** correlation of size and color to early arrival regardless of sex may indicate that a preference for assortative mating exists or that a sex-differential migration strategy is not clearly defined in the early stages of northward *** findings on the sexual dimorphism of Little Buntings provide insight into the evolution of the sex-differential migration of buntings in the East Asian Flyway.

关键词： Digital photography Emberiza pusilla Little Bunting Protandrous migration Sexual dichromatism Sexual dimorphism

Collusion-resistant convertible ring signature schemes

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Science China(Information Sciences) 2015年第1期58卷 134-149页

作者： HWANG Jung Yeon chang Ku-young CHO hyun Sook SONG Boyeon SUSILO Willy Electronics and Telecommunications Research Institute(ETRI) DaejeonKorea Korea Institute of Science and Technology Information (KISTI) DaejeonKorea Centre for Computer and Information Security Research School of Computer Science and Software EngineeringUniversity of WollongongAustralia

A ring signature scheme provides signer ambiguity by hiding a signer in a ring of arbitrary members appropriately. A convertible ring signature scheme is an extension of a ring signature scheme that authenticates a signer and proves that a real signer and no one else generated a ring signature. In this paper, we first show that the recent convertible ring signature scheme proposed by Jeong et al. is vulnerable to collusion ***, we present a formal security model for a convertible ring signature with collusion resistance. The security notion of a convertible ring signature is intrinsically different from that of an ordinary ring signature due to the conversion property. For our collusion resistance, we consider full key exposure, that is, even an adversary who knows all secret keys will not be able to break the collusion resistance. Finally, we construct a novel convertible ring signature scheme with collusion resistance and prove the security of the scheme in the presented security model. We also compare our scheme with the existing ring signature schemes in the literature to show its advantages.

关键词： authentication ring signature anonymity convertibility collusion-resistance

Memristive Devices Based on Two-Dimensional Transition Metal Chalcogenides for Neuromorphic Computing

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Nano-Micro Letters 2022年第4期14卷 29-58页

作者： Ki chang Kwon Ji hyun Baek Kootak Hong Soo young Kim Ho Won Jang Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoul 08826Republic of Korea Interdisciplinary Materials Measurement Institute Korea Research Institute of Standards and Science(KRISS)Daejeon 34133Republic of Korea Department of Materials Science and Engineering Institute of Green Manufacturing TechnologyKorea UniversitySeoul 02841Republic of Korea Advanced Institute of Convergence Technology Seoul National UniversitySuwon 16229Korea

Two-dimensional(2D)transition metal chalcogenides(TMC)and their heterostructures are appealing as building blocks in a wide range of electronic and optoelectronic devices,particularly futuristic memristive and synaptic devices for brain-inspired neuromorphic computing *** distinct properties such as high durability,electrical and optical tunability,clean surface,flexibility,and LEGO-staking capability enable simple fabrication with high integration density,energy-efficient operation,and high *** review provides a thorough examination of high-performance memristors based on 2D TMCs for neuromorphic computing applications,including the promise of 2D TMC materials and heterostructures,as well as the state-of-the-art demonstration of memristive *** challenges and future prospects for the development of these emerging materials and devices are also *** purpose of this review is to provide an outlook on the fabrication and characterization of neuromorphic memristors based on 2D TMCs.

关键词： Two-dimensional materials Memristors Neuromorphic computing Artificial synapses Transition metal chalcogenides

Clinical features of gastric adenoma detected within 3 years after negative screening endoscopy in Korea

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Gastroenterology Report 2023年第1期11卷 406-411页

作者： hyun young Kim Department of Internal Medicine Seoul National University Bundang HospitalSeongnam-siGyeonggi-doKorea

Background:Early detection and management of gastric adenoma are important for preventing gastric *** present study aimed to evaluate the predictors of missed gastric adenoma on screening endoscopy in Korea and identify the risk factors associated with interval precancerous gastric ***:All cases of gastric adenomas diagnosed via screening endoscopy between 2007 and 2019 were *** them,those who had undergone endoscopy within 3 years were included in the present *** gastric adenoma was defined as gastric adenoma diagnosed within 3 years after negative screening ***:In total,295 cases of gastric adenoma were *** these,95(32.2%)were missed gastric adenoma cases(mean age,60.6 years;average interval between final and index endoscopies,12.6months);the remaining 200(67.8%)were newly detected adenoma *** analysis revealed thatmale sex,endoscopist experience,observation time,and presence of gastric intestinalmetaplasia(pathologically proven)were associated with missed gastric *** analysis revealed that gastric intestinal metaplasia(odds ratio[OR],2.736;95%confidence interval[CI],1.320–5.667;P=0.007)and shorter observation time of the index screening endoscopy(B,0.011;OR,0.990;95%CI,0.986–0.993;P<0.001)were independent risk factors for missed gastric *** optimal cut-off for the observation time for detecting gastric adenoma was 3.53minutes(area under curve,0.738;95%CI,0.677–0.799;P<0.001).Conclusions:Gastric intestinal metaplasia is an indication of missed gastric ***,careful inspection of gastric mucosa with gastric intestinal metaplasia and proper observation time can lower the possibility of missing the gastric adenoma during screening.

关键词： gastric adenoma screening endoscopy gastric intestinal metaplasia observation time

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Neural Regeneration Research 2011年第4期6卷 283-287页

作者： Sung Ho Jang Sang-hyun Cho Mi young Lee Yong hyun Kwon Min Cheul chang Department of Physical Medicine and Rehabilitation College of MedicineYeungnam UniversityDaegu 705-717Republic of Korea Department of Physical Therapy Institute of Health ScienceYonsei University College of Health ScienceWounju-siGangwon-do 220-710Republic of Korea Department of Physical Therapy College of Health and TherapyDaegu Haany UniversitySuseongkuDaegu 706-060Republic of Korea Department of Physical Therapy Yeungnam College of Science and TechnologyNamkuDaegu 705-703Republic of Korea

The corticospinal tract （CST） is one of the most important neural tracts for motor function in the human brain. Little is known about age-related changes of the CST. tn this study, we tried to evaluate age-related changes of the CST using diffusion tensor imaging in 60 healthy subjects. The diffusion tensor imaging result revealed that the tract number and fractional anisotropy value were decreased, and the apparent diffusion coefficient （ADC） value was increased with aging. The distribution showed a semilog pattern for tract number, fractional anisotropy and ADC of the CST, and the pattern of each graph was near-linear. When compared with the diffusion tensor imaging parameters of subjects in the 20 s age group, tract number and fractional anisotropy values were significantly decreased in the 50 s-70 s age groups. Likewise, the ADC value was significantly higher in the 50 s-70 s age groups. The CST in the brain of normal subjects degenerated continuously from the 20 s to the 70 s, with a near-linear pattern, and degeneration of the CST began to manifest significantly in the subjects in their 50 s, compared with the subjects in their 20 s.

关键词： corticospinal tract motor function aging diffusion tensor imaging

Characteristic evaluation of Al_2O_3/CNTs hybrid materials for micro-electrical discharge machining

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 28-32页

作者： hyun-Seok TAK chang-Seung HA Ho-Jun LEE hyung-Woo LEE young-Keun JEONG Myung-chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

The characteristic evaluation of aluminum oxide （A1203）/carbon nanotubes （CNTs） hybrid composites for micro-electrical discharge machining （EDM） was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. A1203 composites with different CNT concentrations were synthesized. The electrical characteristic of A1203/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope （FESEM）. The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% A1203 （volume fraction）. In the machining accuracy, many tangles of CNT in A1203/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of A1203/CNTs hybrid composites.

关键词： A1203/CNTs hybrid materials micro-electrical discharge machining micro-hole electrical conductivity

Interface properties and phase formation between surface coated SKD61 and aluminum alloys

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中国有色金属学会会刊：英文版 2009年第4期19卷 875-878页

作者： Se-Weon CHOI young-Chan KIM Se-Hun chang Ik-hyun OH Joon-Sik PARK chang-Seog KANG Automotive Components Center Korea Institute of Industrial Technology Division of Advanced Materials Engineering Hanbat National University

The intermediate phase formation and surface protection effects between SKD61 die mold alloys and aluminum alloys were investigated during a simulated die-casting *** surface coatings of SKD61 alloy were carried out via Si pack cementation coatings at 900 ℃ for 10 h and the ε-FeSi phase *** the coated SKD61 alloy was dipped in the liquid aluminum alloy(ALDC12),the surface coated SKD61 alloys showed better surface properties compared with uncoated SKD61 alloys,i.e.,the intermediate phases(FeSiAl compound) were not produced for the coated SKD61 *** coating layer of ε-FeSi served as a diffusion barrier for the formation of FeSiAl compounds.

关键词：表面涂层铝合金接口特性表面合金涂层表面保护合金生产化合物中间相

Preparation and characterization of SMA/S-POSS hybrid membranes for direct methanol fuel cell applications

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Rare Metals 2006年第Z1期25卷 224-228页

作者： chang young-wook Department of Chemical Engineering Hanyang University AnSan 425-791 South Korea

A novel sulfonated polyhedral oligomeric silsesquioxane(S-POSS) monomer was synthesized successfully in this article. S-POSS acted as a donor of sulfonic acid group and reacted with poly(styrene-co-maleic anhydride) (SMA). FT-IR spectroscopy confirmed the modification through introduction of peaks characteristic of ester linkages and carboxylic groups. The SMA/S-POSS hybrid membranes were fabricated from different S-POSS contents. The proton conductivity and methanol permeability of the hybrid membranes were studied with changing S-POSS content from 5wt.% to 30wt.%. It was found that the proton conductivity and the methanol permeability were dependent on the S-POSS content. Both of proton conductivity and methanol permeability properties improve with increasing S-POSS content. The proton conductivities of the hybrid membranes are in the range of 10-3-10-2 S·cm-1, and the range of methanol permeabilities was between 10-8 and 10-7 cm2·s-1. The membranes show good thermal properties characterized by thermogravimetric analysis (TGA).

关键词： SMA sulfonated polyhedral oligomeric silsesquioxane proton conductivity methanol permeability

Cardiac metastasis from colorectal cancer:A case report

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World Journal of Gastroenterology 2009年第21期15卷 2675-2678页

作者： Pyong Wha Choi Chul Nam Kim Sun Hee chang Woo Ik chang chang young Kim hyun Min Choi Department of Surgery Ilsan Paik HospitalInje University College of Medicine Department of Diagnostic Pathology Ilsan Paik HospitalInje University College of Medicine Department of Chest Surgery Ilsan Paik HospitalInje University College of Medicine Department of Internal Medicine Ilsan Paik HospitalInje University College of Medicine

The heart is an unusual site of metastasis from any malignancy. We report a case of cardiac metastasis from colorectal cancer. A 70-year-old woman was referred with a presumptive diagnosis of sigmoid colon cancer with cardiac myxoma. Two-dimensional echocardiography showed a 4 cm x 4.5 cm mobile mass on the lateral right atrial wall, and computed tomography revealed a low attenuated Iobulating mass in the right atrium. The patient underwent anterior resection for sigmoid colon cancer （T4N2）. Thereafter, she experienced progressive shortness of breath. Therefore, a cardiac operation was performed 2 wk after the colorectal operation. Histological examination revealed adenocarcinoma, which was identical to the primary lesion. Although two- dimensional echocardiography has become the diagnostic test of choice for detecting cardiac tumors, in patients with colorectal cancer showing a cardiac mass, further diagnostic evaluation such as a magnetic resonance imaging might be necessary.

关键词： Heart Cardiac metastasis Colorectalcancer Atrial myxoma Magnetic resonance imaging