• Title/Summary/Keyword: Selectivity factor

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Uses and Gratifications of TV Home-shopping Channels (TV홈쇼핑 채널의 이용과 충족연구)

  • Lee, Sang-Bong
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.241-249
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    • 2011
  • This study takes a uses and gratification theory based approach to identifying the relation between TV home-shopping channel use motivation and purchase intention. The results are summarized as follows. First, in respect of TV home-shopping channel use motivation, the analysis results reveal three factors: convenience, information seeking, and entertainment. Among these, the factor of convenience was the first in the order of importance. Secondly, 1)It is found that use motivation also has some limited influence on purchase intention. 2)Selectivity and involvement degree, the sub-categories of audience activity, are found to be the variables with the highest prediction ability, suggesting a need to give a particular attention to them. 3)In addition, viewing amount, a variable of use behavior, is shown to have a significant influence on purchase intention. The followings are the implications of the study results. First, marketing strategies that enable maximization of shopping convenience are required. Second, there is a need to approach the delivery of TV home-shopping contents as a kind of broadcasting contents on their own rather than merely a medium for selling goods.

Physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via regulating calcium signaling

  • Ding, Ning;Lu, Yanzhu;Cui, Hanmin;Ma, Qinyu;Qiu, Dongxia;Wei, Xueting;Dou, Ce;Cao, Ning
    • BMB Reports
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    • v.53 no.3
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    • pp.154-159
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    • 2020
  • We investigated the effects of physalin A, B, D, and F on osteoclastogenesis induced by receptor activator of nuclear factor κB ligand (RANKL). The biological functions of different physalins were first predicted using an in silico bioinformatic tool (BATMAN-TCM). Afterwards, we tested cell viability and cell apoptosis rate to analyze the cytotoxicity of different physalins. We analyzed the inhibitory effects of physalins on RANKL-induced osteoclastogenesis from mouse bone-marrow macrophages (BMMs) using a tartrate-resistant acid phosphatase (TRAP) stain. We found that physalin D has the best selectivity index (SI) among all analyzed physalins. We then confirmed the inhibitory effects of physalin D on osteoclast maturation and function by immunostaining of F-actin and a pit-formation assay. On the molecular level, physalin D attenuated RANKL-evoked intracellular calcium ([Ca(2+)](i)) oscillation by inhibiting phosphorylation of phospholipase Cγ2 (PLCγ2) and thus blocked the downstream activation of Ca2+/calmodulin-dependent protein kinases (CaMK)IV and cAMP-responsive element-binding protein (CREB). An animal study showed that physalin D treatment rescues bone microarchitecture, prevents bone loss, and restores bone strength in a model of rapid bone loss induced by soluble RANKL. Taken together, these results suggest that physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via suppressing the PLCγ2-CaMK-CREB pathway.

Separation of Isomers and Close Boiling Mixtures by Crystalline Thiourea (결정성 Thiourea에 의한 유기 이성체 및 유사비점 혼합물의 분리)

  • Kim, Kwang-Joo;Lee, Choul-Ho;Lee, Jung-Min
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.129-135
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    • 1996
  • The entrapping capacity of the single hydrocarbons and the entrapping equilibrium data for binary mixtures of the $C_6$ to $C_9$ hydrocarbons on the activated thiourea have been investigated. The entrapping capacity of single component varied irregularly with molecular size and was independent of temperature. In the liquid phase entrapping from binary system, the lower molecular weight hydrocarbon was entrappe preferentially. In the liquid phase entrapping from trimethylbenzene isomer and ethyltoluene isomer, selectivity was found to be related to the relative position of methyl groups in the molecules and hence the electronic configuration. Pseudocumene of a purity of 99.5wt% may be obtained from $C_9$ aromatic raffinate found in naphtha cracking center. Activated thiourea was more efficient than distillation, extractive crystallization and adductive crystallization in terms of separation factor.

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Processing Sliding Window Multi-Joins using a Graph-Based Method over Data Streams (데이터 스트림에서 그래프 기반 기법을 이용한 슬라이딩 윈도우 다중 조인 처리)

  • Zhang, Liang;Ge, Jun-Wei;Kim, Gyoung-Bae;Lee, Soon-Jo;Bae, Hae-Young;You, Byeong-Seob
    • Journal of Korea Spatial Information System Society
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    • v.9 no.2
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    • pp.25-34
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    • 2007
  • Existing approaches that select an order for the join of three or more data streams have always used the simple heuristics. For their disadvantage - only one factor is considered and that is join selectivity or arrival rate, these methods lead to poor performance and inefficiency In some applications. The graph-based sliding window multi -join algorithm with optimal join sequence is proposed in this paper. In this method, sliding window join graph is set up primarily, in which a vertex represents a join operator and an edge indicates the join relationship among sliding windows, also the vertex weight and the edge weight represent the cost of join and the reciprocity of join operators respectively. Then the optimal join order can be found in the graph by using improved MVP algorithm. The final result can be produced by executing the join plan with the nested loop join procedure, The advantages of our algorithm are proved by the performance comparison with existing join algorithms.

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Effects of LiF and TiO$_2$ Additions on Microwave Dielectric and Sintering Properties of ZnWO$_4$ (LiF 및 TiO$_2$ 첨가에 따른 ZnWO$_4$의 고주파 유전특성 및 소결특성)

  • Kim, Yong-Chul;Lee, Kyoung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.131-134
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    • 2003
  • [ $ZnWO_4$ ] shows excellent frequency selectivity due to its high quality factor($Q{\times}f$) at microwave frequencies. However, in order to use $ZnWO_4$ as multilayered wireless communication components, its other properties such as sintering temperature($1050^{\circ}C$), ${\tau}_f$ ($-70ppm/^{\circ}C$) and ${\varepsilon}_r(15.5)$ should be modified. In present study, $TiO_2$ and LiF were used to improve the microwave dielectric and sintering properties of $ZnWO_4$. $TiO_2$ additions to $ZnWO_4$ changed ${\tau}_f$ from negative to positive value, and also increased ${\varepsilon}_r$ due to its high ${\tau}_f$ ($+400ppm/^{\circ}C$) and ${\varepsilon}_r$(100). At 20 mol% $TiO_2$ addition, ${\tau}_f$ was controlled to near zero $ppm/^{\circ}C$ with ${\varepsilon}_r=19.4$ and $Q{\times}f=50000GHz$. However, the sintering temperature was still high to $1100^{\circ}C$. LiF addition to the $ZnWO_4+TiO_2$ mixture was greatly reduced the sintering temperature from $1100^{\circ}C$ to $850^{\circ}C$ due to liquid phase formation. Also LiF addition decreased the ${\tau}_f$ value due to its high negative ${\tau}_f$ value. Therefore, by controlling the $TiO_2$ and LiF amount, temperature stable LTCC material in the $ZnWO_4$-TiO_2-LiF$ system could be fabricated.

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Study on the Pervaporation Characteristic of Water-alcohol Mixtures through Aromatic Polyetherimide Membranes : I. Pervaporation through Structure Change of Symmetric Dense and Asymmetric Structure Membranes (방향계 폴리에테르이미드막의 물-알콜 혼합액의 투과증발 특성에 관한 연구 : I.구조 변화에 따른 투과증발)

  • Kim, S.G.;Jegal, J.G.;Lee, K.-H.
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.945-953
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    • 1997
  • Aromatic polyetherimide membranes were prepared by dry/wet phase inversion method and investigated regarding the pervaporation characteristic of water-alcohol mixtures by using the permselective property of imide group and the structure modification of skin layer of the membrane. The membrane selectivity increased with the reaction time of surface-modification, to some extent, and the density of top layer tends to increases with increasing the reaction time. In the case of dense membrane, the separation factor was 160 and 2000 for 90wt% ethanol mixture and 90wt% isopropanol solution, respectively, which implies that aromatic polyetherimide has a high permselectivity. The temperature dependence of permeation flux seems to follow an Arrhenius type at the temperature range of ($40^{\circ}C-70^{\circ}C$).

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$3^{rd}$ Overtone Mode Energy-Trapped Filter Using $PbTiO_{3}$ System Ceramics ($PbTiO_{3}$계 조성 세라믹스를 이용한 3차 진동모드 에너지 트랩형 필터에 관한 연구)

  • Oh, Dong-On;Yoo, Ju-Hyun;Park, Chang-Yub;Yoon, Hyun-Sang;Lee, Su-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.83-86
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    • 2002
  • In this paper, $3^{rd}$ overtone mode energy-trapped filter using modified $PbTiO_3$ system ceramics was manufactured to apply for intermediate frequency SMD-type filter with the variations of splitted electrode size. To investigate the effects of splitted electrode size on filter characteristics of $3^{rd}$ overtone mode energy-trapped filter, ceramic wafers were fabricated by etching splitted rectangular electrode size($b{\times}d$) of b=0.4, 0.6, 0.8, 1mm, d=0.3, 0.4, 0.5mm, respectively. And then, SMD-type ceramic filter were fabricated with the size of $3.7{\times}3.1mm$. With the variations of b size, insertion loss, 3dB bandwidth and 25dB stop bandwidth showed nearly constant value, but with the variations of d size, insertion loss, 3dB bandwidth, selectivity(shape factor) decreased.⨀؀က?⨀Ⴣ?⨀਀Ⴣ?⨀ꞻꎀ̀ကꮻꎀༀ뮻ꎀ᠀Ȁ햻ꎀĀힻꎀȀ?ꎀ̀?ꎀȀꎀĀꎀĀꎀĀꎀĀꎀЀȀꎀࠀꎀഀڼꎀഀᒼꎀ؀ᮼꎀ䈀ȀȀ悼ꎀऀ檼ꎀഀȀ禼ꎀഀ螼ꎀऀȀȀ鎼ꎀഀȀꊼꎀഀ낼ꎀࠀ즼ꎀԀ쾼ꎀ܀ힼꎀ

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Preparation of Molecularly Imprinted Poly(methacrylic acid) and Its HPLC Separation Characteristics of Retinoids (분자각인 Poly(methacrylic acid)의 제조 및 레티노이드 화합물의 HPLC 분리 특성)

  • 남기훈;권영돈;김덕준
    • Polymer(Korea)
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    • v.26 no.6
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    • pp.710-717
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    • 2002
  • Molecularly imprinted polymers were prepared in particle forms by crosslinking methacrylic acid (MAA)) using all trans-retinoic acid as a template. The HPLC column packed with the prepared molecular imprinted polymers showed high capability in separation of retinoid derivatives. The column capacity factor and selectivity increased with increasing MAA to template ratio when the incorporated template amount was fixed, as it statistically generated more binding sites between host molecules and template. Molecularly imprinted polymer particles prepared via an emulsion polymerization method were round-shaped and their sizes were more uniformly distributed, but their separation capability was inferior to those obtained by solution polymerization method. It was presumably because the loss of interaction strength between MAA and the template due to hydrogen bonding either between MAA and water or between template and water during the synthesis of molecularly imprinted polymers.

A Study on Water Uptake Behavior and Properties of Pervaporation PVA Membrane (투과증발 PVA 분리막의 물 흡수 거동 및 물성 연구)

  • 김광제;박인준;김동권;이수복
    • Membrane Journal
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    • v.5 no.2
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    • pp.74-80
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    • 1995
  • Asymmetric poly(vinyl alcohol) (PVA) membranes were prepared by varying the precipitation conditions of the phase inversion technique, and the influences of precipitation conditions on the water uptake of the membrane were investigate. The degree of water uptake of the membrane increased and reached a certain maximum value, as the precipitation time increased. However, it decreded after that. As the precipition temperauure became lower, the degree of water uptake increased more or less. The addition of a nonionic surfactant to the precipitaon solution was effective reducing the precipitation time by lowering the surface tension of the precipitation solution, but ig didn't change the maximum value of its own degree of water uptake. In addition, the relationship between the degree of water uptake and the separation characteristics and mechanical properies of the membrane were investigated. The selectivity factor of the membrane for pervaperation separation decreased, but the permeate flux increased, respectively, with increasing the degree of water uptake. The tensile strength and elongation of the membrane, respectively, increased to a maximum value with increasing the degree of water uptake, and then decreased abtuptly.

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Factors Influencing Preferential Utilization of RNA Polymerase Containing Sigma-38 in Stationary-Phase Gene Expression in Escherichia coli

  • Kim, Eun-Young;Shin, Min-Sang;Rhee, Joon-Haeng;Hyon E. Choy
    • Journal of Microbiology
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    • v.42 no.2
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    • pp.103-110
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    • 2004
  • In order to understand the molecular basis of selective expression of stationary-phase genes by RNA polymerase containing$\sigma$$\^$38/ (E$\sigma$$\^$38/) in Escherichia coli, we examined transcription from the stationary-phase promoters, katEP, bo1AP, hdeABP, csgBAP, and mcbP, in vivo and in vitro. Although these pro-moters are preferentially recognized in vivo by E$\sigma$$\^$38/, they are transcribed in vitro by both E$\sigma$$\^$38/ and E$\sigma$$\^$70/ containing the major exponential $\sigma$, $\sigma$$\^$70/. In the presence of high concentrations of glutamate salts, how-ever, oldy E$\sigma$$\^$38/ was able to efficiently transcribe from these promoters, which supports the concept that the promoter selectivity of $\sigma$$\^$38/-containing RNA polymerase is observed only under specific reaction con-ditions. The examination of 6S RNA, which is encoded by the ssr1 gene in vivo, showed that it reduced E$\sigma$$\^$70/ activity during the stationary phase, but this reduction of activity did not result in the elevation of E$\sigma$$\^$38/ activity. Thus, the preferential expression of stationary-phase genes by E$\sigma$$\^$38/ is unlikely the con-sequence of selective inhibition of E$\sigma$$\^$70/ by 6S RNA.