• 제목/요약/키워드: k-$\omega$

검색결과 3,472건 처리시간 0.028초

ON THE STRUCTURE OF NON-COMMUTATIVE TORI

  • Boo, Deok-Hoon;Park, Won-Gil
    • 충청수학회지
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    • 제13권1호
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    • pp.1-11
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    • 2000
  • The non-commutative torus $A_{\omega}=C^*(\mathbb{Z}^n,{\omega})$ may be realized as the $C^*$-algebra of sections of a locally trivial $C^*$-algebra bundle over $\widehat{S_{\omega}}$ with fibres $C^*(\mathbb{Z}^n/S_{\omega},{\omega}_1)$ for some totally skew multiplier ${\omega}_1$ on $\mathbb{Z}^n/S_{\omega}$. It is shown that $A_{\omega}{\otimes}M_l(\mathbb{C})$ has the trivial bundle structure if and only if $\mathbb{Z}^n/S_{\omega}$ is torsion-free.

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Experimental Investigation of R(ω), T(ω) and L(ω) for Multi-Layer SRRs and Wires Metamaterials

  • Luo, Hao;Wang, Xian;Liao, Zhangqi;Wang, Tao;Gong, Rongzhou
    • Journal of electromagnetic engineering and science
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    • 제10권3호
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    • pp.186-189
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    • 2010
  • Reflection(R($\omega$)), transmission(T($\omega$)) and loss(L($\omega$)) characteristics of multi-layer metamaterials are investigated experimentally in free space with the incident EM waves perpendicular to the substrate plane. The sample is made of split-ring resonators(SRRs) and wires which are the typical model of metamaterials. The R($\omega$) and T($\omega$) of multi-layer metamaterials have been calculated from the measured S-parameters. In this paper, we got the impedance-matched result according to the curves of R($\omega$), meanwhile the T($\omega$) decreased with increasing number of layers. At last, we attained the result that the L($\omega$) gets to nearly 98% around 8 GHz, with R($\omega$)=T($\omega$)=0. The design presented in this paper achieves experimented loss near unity.

The effect of long-term supplementation with different dietary ${\omega}-6/{\omega}-3$ ratios on mineral content and ex vivo prostaglandin E2 release in bone of growing rabbits

  • Alnouri, Doha Mustafa;El-Din, Mohamed Fekry Serag;Al-Khalifa, Abdulrhman Salih
    • Nutrition Research and Practice
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    • 제8권4호
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    • pp.360-367
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    • 2014
  • BACKGROUND/OBJECTIVES: The aim of this research was to study the different long term effects of consumption of dietary oil sources with varying omega-6/omega-3 (${\omega}-6/{\omega}-3$) polyunsaturated fatty acids (PUFAs) ratios on bone marrow fatty acid level, ex vivo prostaglandin $E_2$ ($PGE_2$) release, and mineral content of bone in rabbits. MATERIALS/METHODS: For this purpose, weaning and female New Zealand white rabbits were purchased and randomly divided into five groups and offered ad libitum diets containing 70 g/kg of added oil for 100 days. The dietary lipid treatments were formulated to provide the following ratios of ${\omega}-6/{\omega}-3$ fatty acids: 8.68 soy bean oil (SBO control), 21.75 sesame oil (SO), 0.39 fish oil (FO), 0.63 algae oil (DHA), and 0.68 algae oils (DHA/ARA). DHA and ARA are two types of marine microalgae of the genus Crypthecodinium cohnii. RESULTS: The dietary treatments had significant effects on the bone marrow fatty acids of rabbits. Rabbits fed the FO diet, containing the highest ${\omega}-3$ PUFA concentration, and those fed the SBO diet showed the highest ${\omega}-6$ PUFA. On the other hand, a positive correlation was observed between Ex vivo $PGE_2$ level and the ${\omega}-6/{\omega}-3$ dietary ratio. Significant effects of dietary treatment on femur Ca, P, Mg, and Zn contents were observed in both genders. CONCLUSIONS: Findings of the current study clearly demonstrated that dietary PUFA, particularly ${\omega}-6/{\omega}-3$ and ARA/EPA ratios are important factors in determining bone marrow fatty acid profile, and this in turn determines the capacity of bone for synthesis of $PGE_2$, thereby reducing bone resorption and improving bone mass during growth.

랫드에서 혈액지질 감소에 관한 오메가 6와 3 지방산 비율의 생화학적 메카니즘 (Biochemical mechanism of the ratio of omega 6 to 3 fatty acid on blood lipid reduction in rats)

  • 이승형;김진수;최두형;김창래;엄경환;박병성
    • 한국응용과학기술학회지
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    • 제34권2호
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    • pp.315-326
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    • 2017
  • 본 연구는 차세대 랫드에서 혈액 지질 감소에 관한 식이 내 오메가 6와 3 지방산 비율의 생화학적 메카니즘을 조사하였다. 실험처리군은 오메가 6:오메가 3비율 0 (대조구), 1:1, 8:1, 19:1로 구분하였다. 혈액 중성지방, 총콜레스테롤, 저밀도지질단백질(LDL-C), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose의 수준은 오메가 6:오메가 3 비율 1:1 그룹에서 가장 낮았다. 혈액 고밀도지질단백질(HDL-C), 인지질의 수준은 오메가 6:오메가 3 비율 1:1 그룹이 가장 높았다. HMG-CoA reductase activity는 전체 저리구 가운데 오메가 6:오메가 3 비율 1:1, 8:1 그룹에서 가장 강하게 억제되었으나 분을 통한 스테롤의 배설량은 촉진되었다. 혈액 오메가 6:오메가 3 비율은 섭취한 식이 내 오메가 6:오메가 3 비율 증가에 따른 농도 의존적으로 감소하였다. 본 연구결과는 부모 세대로부터 차세대 랫드에 이르기까지 오메가 6:오메가 3 비율이 8:1 이하로 낮아진 식이를 섭취하면 영양소 대사작용 활성화 메카니즘에 의한 혈액 중 유해지질 감소, 간 기능 유지 및 성장을 자극한다는 새로운 사실을 나타낸다.

A NEW ALTERNATIVE ELLIPTIC PDE IN EIT IMAGING

  • Kim, Sungwhan
    • 대한수학회보
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    • 제49권6호
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    • pp.1291-1302
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    • 2012
  • In this paper, we introduce a new elliptic PDE: $$\{{\nabla}{\cdot}\(\frac{|{\gamma}^{\omega}(r)|^2}{\sigma}{\nabla}v_{\omega}(r)\)=0,\;r{\in}{\Omega},\\v_{\omega}(r)=f(r),\;r{\in}{\partial}{\Omega},$$ where ${\gamma}^{\omega}={\sigma}+i{\omega}{\epsilon}$ is the admittivity distribution of the conducting material ${\Omega}$ and it is shown that the introduced elliptic PDE can replace the standard elliptic PDE with conductivity coefficient in EIT imaging. Indeed, letting $v_0$ be the solution to the standard elliptic PDE with conductivity coefficient, the solution $v_{\omega}$ is quite close to the solution $v_0$ and can show spectroscopic properties of the conducting object ${\Omega}$ unlike $v_0$. In particular, the potential $v_{\omega}$ can be used in detecting a thin low-conducting anomaly located in ${\Omega}$ since the spectroscopic change of the Neumann data of $v_{\omega}$ is inversely proportional to thickness of the thin anomaly.

Kato's Inequalities for Degenerate Quasilinear Elliptic Operators

  • Horiuchi, Toshio
    • Kyungpook Mathematical Journal
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    • 제48권1호
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    • pp.15-24
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    • 2008
  • Let $N{\geq}1$ and p > 1. Let ${\Omega}$ be a domain of $\mathbb{R}^N$. In this article we shall establish Kato's inequalities for quasilinear degenerate elliptic operators of the form $A_pu$ = divA(x,$\nabla$u) for $u{\in}K_p({\Omega})$, ), where $K_p({\Omega})$ is an admissible class and $A(x,\xi)\;:\;{\Omega}{\times}\mathbb{R}^N{\rightarrow}\mathbb{R}^N$ is a mapping satisfying some structural conditions. If p = 2 for example, then we have $K_2({\Omega})\;= \;\{u\;{\in}\;L_{loc}^1({\Omega})\;:\;\partial_ju,\;\partial_{j,k}^2u\;{\in}\;L_{loc}^1({\Omega})\;for\;j,k\;=\;1,2,{\cdots},N\}$. Then we shall prove that $A_p{\mid}u{\mid}\;\geq$ (sgn u) $A_pu$ and $A_pu^+\;\geq\;(sgn^+u)^{p-1}\;A_pu$ in D'(${\Omega}$) with $u\;\in\;K_p({\Omega})$. These inequalities are called Kato's inequalities provided that p = 2. The class of operators $A_p$ contains the so-called p-harmonic operators $L_p\;=\;div(\mid{{\nabla}u{\mid}^{p-2}{\nabla}u)$ for $A(x,\xi)={\mid}\xi{\mid}^{p-2}\xi$.

銀Ion 및 역상(逆相) HPLC를 이용(利用)한 입체이성체적(立體異性體的) 분석(分析)에 의한 은행종실유(銀杏種實油)의 트리글리세리드의 분자종(分子種)에 관한 연구(硏究) (The Stereospecific Analysis of the Triacylglycerols of Ginkgo Nut Oils by High-Performace Liquid Chromatography(HPLC) in the Silver Ion and Reversed Phase Modes)

  • 조용계;우효경;김훈숙
    • 한국응용과학기술학회지
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    • 제14권1호
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    • pp.61-76
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    • 1997
  • Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC} in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are $C_{18:2{\omega}6}$(39.0mol%), $C_{18:1{\omega}7}$(asclepic acid 21.5mol%), and $C_{18:1{\omega}9}$(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as $C_{20:3{\Delta}^{5,11,14}$ (5.7mol%), $C_{18:2{\Delta}^{5,9}$(2.8mol%), and $C_{18:3}{\Delta}^{5,9,12}$(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a ${\Delta}^5$-non methylene interrupted double bond($^5$-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a ${\Delta}^5$-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; $(C_{18:2{\omega}6)2}/C_{18:1{\omega}7}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$, $C_{16:1{\omega}7}/C_{18:1{\omega}9}/C_{20:3}{\Delta}^{5,11,14}$, $C_{16:1{\omega}7}/C_{18:1{\omega}7}/C_{20:3}{\Delta}^{5,11,14}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $C_{18:1{\omega}9}/C_{18:2}{\Delta}^{5,5}/C_{20:3}{\Delta}^{5,11,14}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$ and $(C_{18:1{\omega}9)2}/C_{18:2{\omega}6}$, while simple triacylglycerols without $C_{18:2{\omega}6})_3$ were not present. Stereospecific analysis showed that fatty acids with ${\Delta}^5$-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.

Association between Omega Fatty Acid Intake and Suicidality : Sex Differences in the General Korean Population

  • Hur, Yang-Im;Lee, Jung Hyun
    • 정신신체의학
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    • 제27권2호
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    • pp.181-190
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    • 2019
  • Objectives : Epidemiological studies in other countries show that a low intake of omega-3 fatty acids (FAs) increases the risk of depression or suicidality. However, no studies have investigated the associations of suicidality with omega-3 FAs in Korea. Hence, this cross-sectional study aimed to investigate the effects of omega FAs on suicidality in the general South Korean population. Methods : The data in this study were sourced from adults (n=215,860) who completed the Sixth Korea National Health and Nutrition Examination Survey (KNHANES VI), and the associations between omega FAs and suicidality were analyzed using multivariate logistic regressions. Results : Our results demonstrated that high omega-3 FA intake was associated with a decreased risk of suicide (OR=0.83, 95% CI : 0.71-0.98) and the high omega-6 to omega-3 FA ratio was associated with an increased risk of suicide (OR=1.25, 95% CI : 1.02-1.54). Additionally, a high intake of omega-3 FAs was associated with a decreased risk of suicide in men, but not in women (OR=0.72, 95% CI : 0.59-0.88). Conclusions : Overall, our findings suggest that a lower intake of omega-3 FA is associated with the increased risk of suicidality in the general Korean population, especially in men.

식이 $\omega$ 3 지방산이 쥐의 신장 인지질과 Na-K-ATPase 활성에 미치는 영향 (Effect of Dietary $\omega$3 Fatty Acid on Kidney Phospholipid and Na-K-ATPase)

  • 손상남
    • Journal of Nutrition and Health
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    • 제19권3호
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    • pp.135-145
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    • 1986
  • 식이 $\omega$3 지방산이 신장의 지질구성 및 기능에 미치는 영향을 조사하기 위해 젖뗀 55-60 g의 흰쥐에게 고등어유, 들깨유, 콩기름을식이의 10% (W/W)포함하는 먹이를 조제하여 24일간 섭취시켰다. 고등어유군의 신장 인지질 지방산에 C20~C22 $\omega$ 3 지방산의 함량이 월등히 많은 반면 들깨유군은 콩기름군에 비해 약간 높을 뿐이어서 C18 : 3 ($\omega$3) 지방산으로 단기간에 쉽게 전환되지 않음을 보였다. C18 : 2($\omega$6) 지방산은 고등어군만 낮았고 C20 : 4($\omega$6)는 들깨유군에서는 낮았지만 고등어유군은 콩기름군과 같은 수준이었다. 또한 고등어유군에서 C18 : 1($\omega$9)을 포함한 단일 불포화 지방산이 높고 포화지방산 함량이 낮은 것도 특징이었다 . 인지질 종류별 분석결과에서 고등어유군이 sphingomyelin 이 높고 phosphatidylethanol-amine이 낮았다. 반면 신장 Cholest대기 함량은 고등어유군이 높았으며, 이러한 지질구성 변화는 신장 Na-K-ATPase 활성감소시킨 것이다.

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