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OFDMA FD-MAC Protocol Based on the Channel Information (채널정보 기반 OFDMA FD-MAC 프로토콜)

  • Cheon, Hye-Rim;Kim, Jae-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.3
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    • pp.451-458
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    • 2015
  • The deployment density of AP increases as well as the density WLAN stations due to increase of WLAN use and the real performance of WLAN is degraded. To improve the performance, there are many PHY/MAC technologies and OFDMA and full duplex are promising technologies among them. In conventional OFDMA WLAN MAC relate works, there are some limitations in terms of channel utilization and collision probability. Thus, it need to research for effective channel allocation protocol. Full duplex can transmit data on the same time and same frequency resource so it can allocate channel more flexible than half duplex. In this paper, we prose the OFDMA FD-MAC(Full Duplex MAC) protocol that it allocates the sub-channels based on the idle channel information for full duplex pair. In addition, it shows the throughput improvement by performance analysis.

Characterization of Tetraploid Somatic Cell Nuclear Transfer-Derived Human Embryonic Stem Cells

  • Shin, Dong-Hyuk;Lee, Jeoung-Eun;Eum, Jin Hee;Chung, Young Gie;Lee, Hoon Taek;Lee, Dong Ryul
    • Development and Reproduction
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    • v.21 no.4
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    • pp.425-434
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    • 2017
  • Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.

Effect of $N_2$ and $O_2$ Properties of STS304 Stainless Steel Films Synthesized by Unbalanced Magnetron Sputtering Process (비대칭 마그네트론 스퍼터링법에 의해 합성된 STR304 스테인리스강 박막에서의 질소와 산소의 첨가 효가)

  • 김광석;이상율;김범석;한전건
    • Journal of the Korean institute of surface engineering
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    • v.34 no.2
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    • pp.89-96
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    • 2001
  • N- or O-doped STS304 stainless films were synthesized by an unbalanced magnetron sputtering process with various argon and reactive gas ($N_2$, $O_2$) mixtures. These films were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Auger electron spectroscopy (AES) and Knoop microhardness tester. The Results from X-ray diffraction (XRD) analysis showed that a STS304 stainless steel film synthesized without reactive gas using a bulk STS304 stainless steel target had a ferrite bcc structure ($\alpha$ phase), while the N-doped STS304 stainless film was consisted of a nitrogen supersaturated fcc structure, which hsa a strong ${\gamma}$(200) phase. In the O-doped films, oxide Phases ($Fe_2$$O_3$ and $Cr_2$$O_3$) were observed from the films synthesized under an excess $O_2$ flow rate of 9sccm. AES analysis showed that nitrogen content in N-doped films increased as the nitrogen flow rate increased. Approximately 43 at.%N in the N-doped film was measured using a nitrogen flow rate of 8sccm. In O-doped film, approximately 15 at.%O was detected using a $O_2$ flow rate of 12sccm. the Knoop microhardness value of N-doped film using a nitrogen flow rate of 8 sccm was measured to be approximately $H_{ k}$ 1200 and this high value could be attributed to the fine grain size and increased residual stress in the N-doped film.

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Ginseng-Whey Beverage Production and Sensory Properties (인삼 유청음료의 제조 및 관능적 특성)

  • 기해진;홍윤호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.2
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    • pp.202-207
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    • 1993
  • Ginseng-whey beverages were prepared with rennet whey, ginseng extract, sweetener, honey and Japanese apricot, inoculated with different strains of lactic acid bacteria and unfermented partly. The samples were stored at 4$^{\circ}C$ or 30$\pm$1$^{\circ}C$ and the sensory evaluations were carried out at 1st, 3rd and 5th week. As a result of sensory test, unfermented ginseng-whey beverage (A) with sweetener and honey (storage at cold temp.) in overall eating quality obtained the best score (8.64~8.86) due to stronger sweetness and weaker sourness, bitterness, astringent taste and aftertaste. The fermented ginseng-whey beverage (C) which was stored at 4$^{\circ}C$ with inoculation of Lac. acidophilus and Lac. delbrueckii sub-sp. bulgaricus and the unfermented samples stored at room temperature with sweetener, honey and Japanese apricot received a good evaluation. But, the fermented beverages (E, F) stored at room temperature obtained the lowest score (2.92~3.58).

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Genotyping of avian pathogenic Escherichia coli by DNA fragment analysis for the differences in simple sequence repeats

  • Han, Mi Na;Byeon, Hyeon Seop;Han, Seong Tae;Jang, Rae Hoon;Kim, Chang Seop;Choi, Seok Hwa
    • Korean Journal of Veterinary Service
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    • v.41 no.4
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    • pp.257-262
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    • 2018
  • Avian pathogenic E. coli (APEC) causes severe economic losses in the poultry farms, due to systemic infections leading to lethal colisepticemia. It causes a variety of diseases from air sac infection to systemic spread leading to septicemia. Secondary infection contains opportunistic infections due to immunosuppression disease. Collibacillosis causes the great problems in the poultry industry in Korea. Thus, it is necessary to identify and classify the characteristics of E. coli isolate of chicken origin to confirm the diversity of symptoms and whether they are transmitted among the farms. Fragment analysis is identify the difference in the number of Variable-Number Tandem-Repeats (VNTRs) for genotyping. VNTRs have repeating structure (Microsatellite, Short tandem repeats; STR, Simple sequence repeats; SSR) in the chromosome. This region can be used as a genetic marker because of its high mutation rate. And various lengths of the amplified DNA fragment cause the difference in the number of repetition of the DNA specific site. The number of repetition sequences indicates the separated size of fragments, so the each fragments can be distinguished by specific samples. The results of the sample show that there is no difference in six microsatellite loci (yjiD, aidB, molR_1, ftsZ, b1668, yibA). There are differences among the farms in relation of the number of repetitions of other six microsatellite loci (ycgW, yaiN, yiaB, mhpR, b0829, caiF). Four (ycgW, yiaB, b0829, caiF) of these six microsatellite loci show statistically significant differences (P<0.05). It means that the analysis using four microsatellite loci including ycgW, yiaB, b0829, and caiF can confirm among the farms. Five E. coli samples in one farm have same SSR repetition at all markers. But, there are significant differences from other farms at Four (ycgW, yiaB, b0829, caiF) microsatellite loci. These results emphasize again that the four microsatellite loci makes a difference in the amplified DNA fragments, enabling it to be used for E. coli genotyping.

Complete mitochondrial genome of Rotunda rotundapex Miyata & Kishida 1990 (Lepidoptera: Bombycidae), which was named as Bombyx shini Park & Sohn 2002

  • Park, Jeong Sun;Kim, Min Jee;Kim, Iksoo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.44 no.2
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    • pp.55-64
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    • 2022
  • Bombyx shini Park & Sohn, 2002 (Lepidoptera: Bombycidae), which was listed as an endemic species in South Korea has recently been renamed as the East Asian silk moth Rotunda rotundapex Miyata & Kishida, 1990 (Lepidoptera: Bombycidae). In this study, we sequenced the complete mitochondrial genome (mitogenome) of the R. rotundapex to announce genomic characteristics and to clarify its validity with a new name. The 15,294-bp long complete mitogenome comprises a typical set of genes [13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes] and one major noncoding, A + T-rich region, with an arrangement identical to that observed in most lepidopteran mitogenomes. The A/T content of the whole mitogenome was 79.22%; however, it varied among the regions/genes as follows: A + T-rich region, 91.62%; srRNA, 84.67%; lrRNA, 83.01%; tRNAs, 81.43%; and PCGs, 77.46%. Phylogenetic analyses of 35 species in the Bombycoidea superfamily showed the sister relationship between the families Sphingidae and Bombycidae s. str., with the higher nodal support [bootstrap support (BS) = 78%]. The Saturniidae was placed as the sister to the two families, but the nodal support for this relationship was low (BS = 53%). Current R. rotundapex was placed together with previously reported con-species with the highest nodal support, forming a separate clade from Bombyx, validating that B. shini can have a new genus name, Rotunda. However, the Korean R. rotundapex showed a substantial sequence divergence at 5.28% to that originated from an individual of type locality Taiwan in 1,459-bp of COI sequences. Considering such a high sequence divergence an additional study, which includes morphological and DNA barcoding data from further extensive distributional range maybe is needed for further robust taxonomic conclusion.

Prevalence and characterization of pathogenic Escherichia coli from carcasses and environmental samples of cattle and pig slaughterhouses (소와 돼지 도축장 도체 및 환경에서 분리된 병원성대장균 분포 및 특성조사)

  • Hong, Serim;Kang, Hye Jeong;Moon, Jin-San;Yoon, Soon-Seek;Kim, Ha-Young
    • Korean Journal of Veterinary Service
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    • v.45 no.3
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    • pp.191-199
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    • 2022
  • We investigated the virulence genes, O-serotypes, antimicrobial resistance of pathogenic E. coli isolated from carcasses (n=455) and environmental (n=372) samples of 11 cattle and 12 pig slaughterhouses from December 2020 to December 2021. E. coli were isolated from nine carcasses (2.0%), three slaughter facilities (1.4%), two utensils (2.7%) and three abattoir workers (3.5%) from four cattle and four pig slaughterhouses. Among all isolates, 13 STEC (76.5%) were identified, followed by four EPEC (23.5%). As a result of the antibiotic susceptibility test, all isolates were resistant to at least one antimicrobial, of which 70.6% isolates showed multidrug resistance patterns. The serotypes were diverse in pigs compared to cattle, with serotypes O18, O66, O109 in cattle and O9, O76, O85, O100, O153, and O159 in pigs. In a single cattle slaughterhouse, eight STEC O66 were isolated from various types of sample (4 slaughter animal surfaces, 3 gloves, and 1 knife) with two antimicrobial resistance patterns (CHL-FIS-STR and CHL-FIS). Those two types of strain were suspected cross-contamination from utensils to slaughter animal surfaces. These results showed that pathogenic E. coli were detected in carcasses and various environmental samples in cattle and pig slaughterhouses. Nationwide monitoring and hygiene management are required to prevent cross-contamination of STEC isolate slaughterhouses.

Vibration behavior of partially bio-sourced sandwich panel with orthogonally stiffened core: Analytical and experiment study

  • Boussoufi, Aicha;Errouane, Lahouaria;Sereir, Zouaoui;Antunes, Jose V.;Debut, Vincent
    • Advances in aircraft and spacecraft science
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    • v.9 no.3
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    • pp.169-193
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    • 2022
  • By the present paper, both experimental and analytical models have been proposed to study the vibration behavior of partially bio-sourced sandwich panel with orthogonally stiffened core. For a variable mass fraction of Alfa fibers from 5% to 15%, impregnated in a Medapoxy STR resin, this panel were manufactured by molding the orthogonally stiffened core then attached it with both skins. Using simply supported boundary conditions, a free vibration test was carried out using an impact hammer for predicting the natural frequencies, the mode shapes and the damping coefficient versus the fibers content. In addition, an analytical model based on the Higher order Shear Deformation Theory (HSDT) was developed to predict natural frequencies and the mode shapes according to Navier's solution. From the experimental test, we have found that the frequency increases with the increase in the mass fraction of the fibers until 10%. Beyond this fraction, the frequencies give relatively lower values. For the analytical model, variation of the natural frequencies increased considerably with side-to-thickness ratio (a/H) and equivalent thickness of the core to thickness of the face (hs/h). We concluded that, the vibration behavior was significantly influenced by geometrical and mechanical properties of the partially bio-sourced sandwich panel.

Antioxidant Activity and Anti-Obesity Effects of Mixture of Brassica juncea and Black Rice Bran (갓과 흑미강 혼합물의 항산화 활성 및 지방세포 억제 효과)

  • Ji-Heon Im;June seok Lim;Xionggao Han;Xiao Men;Geon Oh;Geun hee Cho;Sun-Il Choi;Woonsang Hwang;Ok-Hwan Lee
    • The Korean Journal of Food And Nutrition
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    • v.36 no.4
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    • pp.244-252
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    • 2023
  • This study was conducted to provide basic data on the antioxidant activity, inhibition of adipocyte differentiation and reactive oxygen species (ROS) production of a mixture of Brassica juncea extract (BJE) and fermented black rice fraction (BRF). We investigated the total phenol content, total flavonoid content, antioxidant effects (DPPH radical scavenging, ABTS radical scavenging, reducing power, FRAP and ORAC assay) and anti-obesity activity of the mixture in 3T3-L1 cells. Our results showed that the total phenol and flavonoid content increased with increasing BRF mixture ratio. The antioxidant activity increased as the BRF mixture ratio increased. In addition, BJE and BRF mixtures did not show any cytotoxicity during the 3T3-L1 differentiation period. During adipocyte differentiation, BJE and BRF mixtures significantly inhibited lipid accumulation and ROS production compared to the control group. These results warrant further experiments to develop an anti-obesity functional food using a mixture of BJE and BRF.

Design of the emotion expression in multimodal conversation interaction of companion robot (컴패니언 로봇의 멀티 모달 대화 인터랙션에서의 감정 표현 디자인 연구)

  • Lee, Seul Bi;Yoo, Seung Hun
    • Design Convergence Study
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    • v.16 no.6
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    • pp.137-152
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    • 2017
  • This research aims to develop the companion robot experience design for elderly in korea based on needs-function deploy matrix of robot and emotion expression research of robot in multimodal interaction. First, Elder users' main needs were categorized into 4 groups based on ethnographic research. Second, the functional elements and physical actuators of robot were mapped to user needs in function- needs deploy matrix. The final UX design prototype was implemented with a robot type that has a verbal non-touch multi modal interface with emotional facial expression based on Ekman's Facial Action Coding System (FACS). The proposed robot prototype was validated through a user test session to analyze the influence of the robot interaction on the cognition and emotion of users by Story Recall Test and face emotion analysis software; Emotion API when the robot changes facial expression corresponds to the emotion of the delivered information by the robot and when the robot initiated interaction cycle voluntarily. The group with emotional robot showed a relatively high recall rate in the delayed recall test and In the facial expression analysis, the facial expression and the interaction initiation of the robot affected on emotion and preference of the elderly participants.