• Kyungpook Mathematical Journal
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• 제54권4호
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• pp.619-627
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• 2014

Let $\mathcal{M}(S)$ denote the set of all $m{\times}n$ matrices over a semiring S. For $A{\in}\mathcal{M}(S)$, zero-term rank of A is the minimal number of lines (rows or columns) needed to cover all zero entries in A. In [5], the authors obtained that a linear operator on $\mathcal{M}(S)$ preserves zero-term rank if and only if it preserves zero-term ranks 0 and 1. In this paper, we obtain new characterizations of linear operators on $\mathcal{M}(S)$ that preserve zero-term rank. Consequently we obtain that a linear operator on $\mathcal{M}(S)$ preserves zero-term rank if and only if it preserves two consecutive zero-term ranks k and k + 1, where $0{\leq}k{\leq}min\{m,n\}-1$ if and only if it strongly preserves zero-term rank h, where $1{\leq}h{\leq}min\{m,n\}$.

• The Korean Journal of Physiology and Pharmacology
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• 제7권6호
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• pp.303-306
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• 2003

Metabotropic glutamate receptors (mGluRs), classified into three groups (group I, II, III), play a critical role in modulation of synaptic transmission at central and peripheral synapses. In the present study, extracellular field potential recording techniques were used to investigate effects of mGluR agonists on excitatory synaptic transmission at thalamic input synapses onto the lateral amygdala. The non-selective mGluR agonist t-ACPD ($100{\mu}M$) produced reversible, short-term depression, but the group III mGluR agonist L-AP4 ($50{\mu}M$) did not have any significant effects on amygdala synaptic transmission, suggesting that group I and/or II mGluRs are involved in the modulation by t-ACPD. The group I mGluR agonist DHPG ($100{\mu}M$) produced reversible inhibition as did t-ACPD. Unexpectedly, the group II mGluR agonist LCCG-1 ($10{\mu}M$) induced long-term as well as short-term depression. Thus, our data suggest that activation of group I or II mGluRs produces short-term, reversible depression of excitatory synaptic transmission at thalamic input synapses onto the lateral amygdala. Considering the long-term effect upon activation of group II mGluRs, lack of long-term effects upon activation of group I and II mGluRs may indicate a possible cross-talk among different groups of mGluRs.

• Kyungpook Mathematical Journal
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• 제50권4호
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• pp.465-472
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• 2010

In this paper, we consider two extreme sets of zero-term rank sum of fuzzy matrix pairs: $$\cal{z}_1(\cal{F})=\{(X,Y){\in}\cal{M}_{m,n}(\cal{F})^2{\mid}z(X+Y)=min\{z(X),z(Y)\}\};$$ $$\cal{z}_2(\cal{F})=\{(X,Y){\in}\cal{M}_{m,n}(\cal{F})^2{\mid}z(X+Y)=0\}$$. We characterize the linear operators that preserve these two extreme sets of zero-term rank sum of fuzzy matrix pairs.

• 생약학회지
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• 제43권3호
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• pp.257-264
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• 2012

The purpose of this study was to estimate the shelf-life of Ssanghwa-tang by long-term storage test. Experiments were conducted to evaluate the stability such as the selected physicochemical, pH, identification, heavy metal, microbiological experiment under a long-term storage test of Ssanghwa-tang. The significant change was not showed in pH, heavy metal, microbiological, identification test and quantitative analysis based on long-term storage test. The contents of albiflorin, paeoniflorin, cinnamic acid, liquiritin, and glycyrrhizin in long-term storage test were 66.8-93.1 ${\mu}g/mL$, 429.0-495.0 ${\mu}g/mL$, 3.8-4.4 ${\mu}g/mL$, 32.0-38.1 ${\mu}g/mL$, and 66.8-71.7 ${\mu}g/mL$, respectively. Shelf-lifes by 5 compounds about 3 lots at room temperature were predicted 21-37, 14-21, and 16-72 months, respectively. The suggested shelf-life would be helpful on the storage and distribution of herbal medicine.

• 한국환경과학회지
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• 제26권2호
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• pp.221-230
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• 2017

To determine the effect of air pollution reduction policies, the long-term trend of air pollutants should be analyzed. Kolmogorov-Zurbenko (KZ) filter is a low-pass filter, produced through repeated iterations of a moving average to separate each variable into its temporal components. The moving average for a KZ(m, p) filter is calculated by a filter with window length m and p iterations. The output of the first pass subsequently becomes the input for the next pass. Adjusting the window length and the number of iterations makes it possible to control the filtering of different scales of motion. To break down the daily mean $PM_{10}$ into individual time components, we assume that the original time series comprises of a long-term trend, seasonal variation, and a short-term component. The short-term component is attributable to weather and short-term fluctuations in precursor emissions, while the seasonal component is a result of changes in the solar angle. The long-term trend results from changes in overall emissions, pollutant transport, climate, policy and/or economics. The long-term trend of the daily mean $PM_{10}$ decreased sharply from $59.6ug/m^3$ in 2002 to $44.6ug/m^3$ in 2015. This suggests that there was a long-term downward trend since 2005. The difference between the unadjusted and meteorologically adjusted long-term $PM_{10}$ is small. Therefore, we can conclude that $PM_{10}$ is unaffected by the meteorological variables (total insolation, daily mean temperature, daily mean relative humidity, daily mean wind speed, and daily mean local atmospheric pressure) in Busan.

• The Korean Journal of Physiology and Pharmacology
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• 제16권2호
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• pp.139-144
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• 2012

It has been reported that activation of metabotropic glutamate receptor 1 (mGluR1) can mediate endocannabinoid-induced short-term depression of synaptic transmission in cerebellar parallel fiber (PF)-Purkinje cell (PC) synapse. mGluR1 has signaling pathways involved in intracellular calcium increase which may contribute to endocannabinoid release. Two major mGluR1-evoked calcium signaling pathways are known: (1) slow-kinetic inward current carried by transient receptor potential canonical (TRPC) channel which is permeable to $Ca^{2+}$; (2) $IP_3$-induced calcium release from intracellular calcium store. However, it is unclear how much each calcium source contributes to endocannabinoid signaling. Here, we investigated whether calcium influx through mGluR1-evoked TRPC channel contributes to endocannabinoid signaling in cerebellar Purkinje cells. At first, we applied SKF96365 to inhibit TRPC, which blocked endocannabinoid-induced short-term depression completely. However, an alternative TRP channel inhibitor, BTP2 did not affect endocannabinoid-induced short-term depression although it blocked mGluR1-evoked TRPC currents. Endocannabinoid signaling occurred normally even though the TRPC current was mostly blocked by BTP2. Our data imply that TRPC current does not play an important role in endocannabinoid signaling. We also suggest precaution in applying SKF96365 to inhibit TRP channels and propose BTP2 as an alternative TRPC inhibitor.

• The Korean Journal of Physiology and Pharmacology
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• 제5권6호
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• pp.503-510
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• 2001

Long-term treatment of cultured bovine adrenal medullary chromaffin (BAMC) cells with arachidonic acid $(100\;{\mu}M),$ angiotesnin II (100 nM), prostaglandin $E_2\;(PGE_2;\;10\;{\mu}M),$ veratridine $(2\;{\mu}M)$ or KCl (55 mM) for 24 hrs increased both norepinephrine and epinephrine levels in the supernatant. Pretreatment with staurosporine (10 nM), a protein kinase C (PKC) inhibitor, completely blocked increases of norepinephrine and epinephrine secretion induced by arachidonic acid, angiotensin II, $PGE_2,$ veratridine or KCl. In addition, K252a, another PKC inhibitor whose structure is similar to that of staurosporine, effectively attenuated both norepinephrine and epinephrine secretion induced by arachidonic acid. However, K252a did not affect the catecholamine secretion induced by angiotensin II, $PGE_2,$ veratridine or KCl. Our results suggest that staurosporine may inhibit long-term catecholamine secretion induced by various secretagogues in a mechanism other than inhibiting PKC signaling. Furthermore, long-term secretion of catecholamines induced by arachidonic acid may be dependent on PKC pathway.

• 동력기계공학회지
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• 제19권5호
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• pp.45-51
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• 2015

Grade 91 steel is used for the major structural components of Generation-IV reactor systems such as a very high temperature reactor (VHTR) and sodium-cooled fast reactor (SFR). Since these structures are designed for up to 60 years at elevated temperatures, the prediction of long-term creep life is very important to determine an allowable design stress of elevated temperature structural component. In this study, a large body of creep rupture data was collected through world-wide literature surveys, and using these data, the long-term creep life was predicted in terms of three methods: Larson-Miller (L-M), Manson-Haferd (M-H) and Wilshire methods. The results for each method was compared using the standard deviation of error. The L-M method was overestimated in the longer time of a low stress. The Wilshire method was superior agreement in the long-term life prediction to the L-M and M-H methods.

• Advances in Traditional Medicine
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• 제9권1호
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• pp.39-48
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• 2009

We have evaluated the effect of long term treatment of Enicostemma littorale (E. littorale) in type 2 diabetic patients taking pills of aqueous extract of E. littorale regularly as a complimentary medicine for at least 9 months. The effects of E. littorale on glycemic control, lipid profile, cardiac function and DNA damage in these patients were compared with those who had not been regular in taking E. littorale but regular in taking other conventional anti-diabetics. Our data suggest that, E. littorale can maintain normal blood glucose, serum insulin, serum triglycerides levels of type 2 diabetic patients if taken regularly. E. littorale also improves insulin sensitivity, and normalize disturbed lipogram and elevated creatinine levels, thereby produces beneficial effect in preventing cardiovascular complications and may preserve the kidney function. The finding that E. littorale also prevents DNA damage suggest a long term effect in diabetic patients. E. littorale thus can be considered as safe supplementary therapy for a long term and effective management of type 2 diabetic patients.

• 한국재난정보학회 논문집
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• 제12권4호
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• pp.329-341
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• 2016

신종 인플루엔자 유행과 같은 사회적 위기는 기업을 비롯한 다양한 조직에 영향을 미치게 되고 이에 대한 활동과 결과는 사회적 위기와 조직의 특성에 따라 다를 것이다. 사회적 위기에 대한 조직의 단기적인 대응을 이해하는데 ser-M 모델을 이용한 메카니즘 기반 관점은 현재까지 사용되지 않았으나, 본 연구를 통해 ser-M 모델을 활용한 연구가 단기간 특정 사건을 대상으로도 가능함을 보이고, 위기나 재난과 관련된 접근 방법의 하나로 활용할 수 있음을 보고자 하였다. 본 연구에서는 신종 인플루엔자를 직접 대응하는 의료기관에서 사회적 위기로서 신종 인플루엔자에 어떻게 대처하였는지를 알아봄과 동시에 그 활동과 운영의 변화를 최신의 ser-M 모델을 적용하여 보고자 하였다. 본 사례로 볼 때 신종 플루 유행과 같은 외부 요인으로 인한 기업의 위기 상황에서 효율적 대응을 위한 준비와 그 과정에 대한 경영학적 접근, 특히 ser-M 모델을 적용한 기업 측면의 구체적 사례 연구가 부족한 데 대한 초기단계 연구로서 의의가 있을 것이며, 메커니즘 이론이 장기적 경영 전략 뿐 아니라 단기적 외부 상황 변화에 따른 기업의 영향을 분석하는 데에도 사용 가능할 것으로 사료된다.