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Analysis on the Performance Unfairness Problem of the Heterogeneous Environment with IEEE 802.11b and 802.11e (IEEE 802.11e와 802.11b 표준이 혼재하는 이종환경에서의 불공평 문제 성능 분석)

  • Lim Yujin
    • The KIPS Transactions:PartC
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    • v.12C no.2 s.98
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    • pp.217-222
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    • 2005
  • The IEEE 802.11 based wireless local area networks are candidates to lead the broadband connectivity in the home and office scenarios. Recently IEEE proposed the 802.11e as a new standard to provide appropriate Quality of Services to a plethora of emerging real-time multimedia and high demanding applications such as high definition movie and audio distribution, video-conference and voice over IP. This paper studies the IEEE 802.11e/IEEE 802.11b interactions focusing on potential unfairness problems that might appear in networks with heterogeneous wireless LAN technologies as well as in the IEEE 802.11e deployment phase.

Design of an $tan^{-1}$ circuit for the carrier frequency offset compensation of IEEE 802.11a PHY (IEEE 802.11a PHY의 반송과 주파수 옵셋 보정을 위한 $tan^{-1}$ 회로 설계)

  • Kim, Su-Young;Lim, Choon-Sik;Cho, Kyoung-Rok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.4A
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    • pp.247-255
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    • 2003
  • In this paper, an $tan^{-1}$ circuit for the frequency synchronization of OFDM based IEEE 802.11a is presented. The proposed circuit consists of a divider, an $tan^{-1}$ ROM and a phase detector, which can detect frequency offset within 0.0491 rad. The circuit implemented with FPGA shows a pull-in range of under ${\pm}625KHz$ at 5dB AWGN. It may be useful for IEEE 802.11a WLAN standard.

Prenatal diagnosis of a de novo ring chromosome 11

  • Park, Ju-Yeon;Lee, Moon-Hee;Lee, Bom-Yi;Lee, Yeon-Woo;Ryu, Hyun-Mee;Park, So-Yeon
    • Journal of Genetic Medicine
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    • v.4 no.1
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    • pp.80-83
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    • 2007
  • A 36-year-old pregnant woman was referred for amniocentesis at 19.5 weeks gestation because of advanced maternal age and evidence of increased risk for Edward syndrome in the maternal serum screening test. Cytogenetic analysis of the cultured amniotic fluid cells revealed mosaicism for ring chromosome 11: 46,XX,r(11)[65]/ 45,XX,-11[16]/ 46,XX [34]. Parental karyotypes were normal. A targeted ultrasound showed intrauterine grow th restriction (IUGR). Cordocentesis was performed to characterize the ring chromosome and to rule out tissue specific mosaicism. Karyotype was confirmed as 46,XX,r(11) (p15.5q24.2)[229]/45,XX,-11[15]. And a few new form of ring w ere detected in this culture. The deletion of subtelomeric regions in the ring chromosome were detected by fluorescent in situ hybridization (FISH). The pregnancy was terminated. The fetal autopsy showed a growth-retarded female fetus with rocker bottom feet. We report a case of prenatally detected a de novo ring chromosome 11.

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Self-Sufficient Catalytic System of Human Cytochrome P450 4A11 and NADPH-P450 Reductase

  • Han, Song-Hee;Eun, Chang-Yong;Han, Jung-Soo;Chun, Young-Jin;Kim, Dong-Hyun;Yun, Chul-Ho;Kim, Dong-Hak
    • Biomolecules & Therapeutics
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    • v.17 no.2
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    • pp.156-161
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    • 2009
  • The human cytochrome P450 4A11 is the major monooxygenase to oxidize the fatty acids and arachidonic acid. The production of 20-hydroxyeicosatetraenoic acid by P450 4A11 has been implicated in the regulation of vascular tone and blood pressure. Oxidation reaction by P450 4A11 requires its reduction partners, NADPH-P450 reductase (NPR). We report the functional expression in Escherichia coli of bicistronic constructs consisting of P450 4A11 encoded by the first cistron and the electron donor protein, NPR by the second. Typical P450 expression levels of wild type and several N-terminal modified mutants was observed in culture media and prepared membrane fractions. The expression of functional NPR in the constructed P450 4A11: NPR bicistronic system was clearly verified by reduction of nitroblue tetrazolium. Membrane preparation containing P450 4A11 and NPR efficiently oxidized lauric acid mainly to $\omega$-hydroxylauric acid. Bicistronic coexpression of P450 4A11 and NPR in E. coli cells can be extended toward identification of novel drug metabolites or therapeutic agents involved in P450 4A11 dependent signal pathways.

Molecular characterization and expression pattern of a novel Keratin-associated protein 11.1 gene in the Liaoning cashmere goat (Capra hircus)

  • Jin, Mei;Cao, Qian;Wang, Ruilong;Piao, Jun;Zhao, Fengqin;Piao, Jing'ai
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.3
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    • pp.328-337
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    • 2017
  • Objective: An experiment was conducted to determine the relationship between the KAP11.1 and the regulation wool fineness. Methods: In previous work, we constructed a skin cDNA library and isolated a full-length cDNA clone termed KAP11.1. On this basis, we conducted a series of bioinformatics analysis. Tissue distribution of KAP11.1 mRNA was performed using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. The expression of KAP11.1 mRNA in primary and secondary hair follicles was performed using real-time PCR (real-time polymerase chain reaction) analysis. The expression location of KAP11.1 mRNA in primary and secondary hair follicles was performed using in situ hybridization. Results: Bioinformatics analysis showed that KAP11.1 gene encodes a putative 158 amino acid protein that exhibited a high content of cysteine, serine, threonine, and valine and has a pubertal mammary gland) structural domain. Secondary structure prediction revealed a high proportion of random coils (76.73%). Semi-quantitative RT-PCR showed that KAP11.1 gene was expressed in heart, skin, and liver, but not expressed in spleen, lung and kidney. Real time PCR results showed that the expression of KAP11.1 has a higher expression in catagen than in anagen in the primary hair follicles. However, in the secondary hair follicles, KAP11.1 has a significantly higher expression in anagen than in catagen. Moreover, KAP11.1 gene has a strong expression in inner root sheath, hair matrix, and a lower expression in hair bulb. Conclusion: We conclude that KAP11.1 gene may play an important role in regulating the fiber diameter.

Discovery of Novel 11β-HSD1 Inhibitors by Pharmacophore-Based Virtual Screening

  • Kim, Nam-Doo;Lee, Youn-Ho;Han, Chang-Kyun;Ahn, Soon-Kil
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2365-2368
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    • 2012
  • The $11{\beta}$-hydroxysteroid dehydrogenase type 1 ($11{\beta}$-HSD1) enzyme is involved in modulation of glucocorticoid activity within target tissues. This enzyme may contribute to obesity and/or metabolic disease through its action in adipose or liver tissue. Inhibition of $11{\beta}$-HSD1 has major therapeutic potential for glucocorticoid-associated diseases, including obesity, diabetes (wound healing), and muscle atrophy. To develop such therapeutics, we performed a pharmacophore-based virtual screening (VS) for identification of novel $11{\beta}$-HSD1 inhibitors and found that the VS hit compounds show potent inhibition of $11{\beta}$-HSD1 enzyme activity. Further, we present a binding model for active compounds. The proposed pharmacophore may serve as a useful guideline for future design of new chemical entities as $11{\beta}$-HSD1-targeted antidiabetic agents.

A Functional Analysis of OsCPK11, a Calcium-dependent Protein Kinase (CDPK) Gene in Rice (벼의 칼슘-의존성 단백질 카이네즈 유전자인 OsCPK11의 기능적 분석)

  • Lee, Su-Hee;Lee, Jeong-Eun;Day, Philip;Gilroy, Simon;Kim, Sung-Ha
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1233-1244
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    • 2017
  • CDPKs have pivotal roles in plant $Ca^{2+}$-mediated transduction signaling. A total of 29 CDPK genes have been identified in rice (Oryza sativa L.), but their key functions have not been completely noted. This study focused on the OsCPK11 gene, which has not been studied, to determine its functional characteristics. A study of tissue-specific expressions revealed that the OsCPK11 gene is expressed in young leaves, mature leaves and flowers of rice. An expression of the gene was also confirmed in gibberellin-treated aleurone layers of rice. Regarding the phenotypic characteristics of Tos17-inserted OsCPK11 mutants, the heights of the mutants were not distinguishable from the heights of wild type plants, but the number of caryopses and the caryopses' weights were significantly statistically different. In addition, many grains of the mutants had white belly materials in their endosperm. The cDNA of the OsCPK11 was cloned, and an OsCPK11 protein of about 60.5 kD was obtained by using a GST affinity chromatography and an SDS-PAGE. An analysis of the amino-acid sequence of the protein indicated that the OsCPK11 protein has the structural characteristics of typical CDPKs. The results provided useful information about the functions of the OsCPK11 gene and further noted the roles CDPKs have in $Ca^{2+}$-mediated signaling in plants.

Design of Link Cost Metric for IEEE 802.11-based Mesh Routing (IEEE 802.11 MAC 특성을 고려한 무선 메쉬 네트워크용 링크 품질 인자 개발)

  • Lee, Ok-Hwan;Kim, Seong-Kwan;Choi, Sung-Hyun;Lee, Sung-Ju
    • Journal of KIISE:Information Networking
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    • v.36 no.5
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    • pp.456-469
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    • 2009
  • We develop a new wireless link quality metric, ECOT(Estimated Channel Occupancy Time) that enables a high throughput route setup in wireless mesh networks. The key feature of ECOT is to be applicable to diverse mesh network environments where IEEE 802.11 MAC (Medium Access Control) variants are used. We take into account the exact operational features of 802.11 MAC protocols, such as 802.11 DCF(Distributed Coordination Function), 802.11e EDCA(Enhanced Distributed Channel Access) with BACK (Block Acknowledgement), and 802.11n A-MPDU(Aggregate MAC Protocol Data Unit), and derive the integrated link metric based on which a high throughput end-to-end path is established. Through extensive simulation in random-topology settings, we evaluate the performance of proposed link metric and present that ECOT shows 8.5 to 354.4% throughput gain over existing link metrics.

WNT11 is a direct target of early growth response protein 1

  • Kim, JuHwan;Jung, Euitaek;Ahn, Sung Shin;Yeo, Hyunjin;Lee, Jeong Yeon;Seo, Jeong Kon;Lee, Young Han;Shin, Soon Young
    • BMB Reports
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    • v.53 no.12
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    • pp.628-633
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    • 2020
  • WNT11 is a member of the non-canonical Wnt family and plays a crucial role in tumor progression. However, the regulatory mechanisms underlying WNT11 expression are unclear. Tumor necrosis factor-alpha (TNFα) is a major inflammatory cytokine produced in the tumor microenvironment and contributes to processes associated with tumor progression, such as tumor invasion and metastasis. By using site-directed mutagenesis and introducing a serial deletion in the 5'-regulatory region of WNT11, we observed that TNFα activates the early growth response 1 (EGR1)-binding sequence (EBS) in the proximal region of WNT11 and that the transcription factor EGR1 is necessary for the TNFα-induced transcription of WNT11. EGR1 bound directly to the EBSs within the proximal 5'-regulatory region of WNT11 and ectopic expression of EGR1 stimulated WNT11 promoter activity, whereas the knockdown of EGR1 expression by RNA interference reduced TNFα-induced WNT11 expression in T47D breast cancer cells. We also observed that mitogen-activated protein kinases (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 kinase mediated TNFα-induced transcription of WNT11 via EGR1. Our results suggest that EGR1 directly targets WNT11 in response to TNFα stimulation in breast cancer cells.

Performance Analysis of IEEE 802.11n System adapting Frame Aggregation Methods (Frame Aggregation 기법을 적용한 IEEE 802.11n 시스템 성능 분석)

  • Lee, Yun-Ho;Kim, Joo-Seok;Kim, Kyung-Seok
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.515-527
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    • 2009
  • IEEE 802.11n is an ongoing next-generation WLAN(Wireless Local Area Network) standard that supports a very high-speed connection with more than 100Mb/s data throughput measured at the MAC(Medium Access Control) layer. Study trends of IEEE 802.11n show two aspects, enhanced data throughput using aggregation among packets in MAC layer, and better data rates adapting MIMO(Multiple-Input Multiple-Output) in PHY(Physical) layer. But, the former doesn't consider wireless channel and the latter doesn't consider aggregation among packets for reality. Therefore, this paper analyzes data throughput for IEEE 802.11n considering MAC and PHY connection. A-MPDU(Aggregation-MAC Protocol Data Unit) and A-MSDU(Aggregation-MAC Service Unit) is adapted considering multi-service in MAC layer, WLAN MIMO TGn channel using SVD(Singular Value Decomposition) is adapted considering MIMO and wireless channel in PHY layer. Consequently, Simulation results shows throughput between A-MPDU and A-MSDU. Also, We use Ns-2(Network simulator-2) for reality.