• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.47-48
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• 2014

기본적으로 전력전송개념에서 최대의 전력이 전달하기 위해서는 전력전송단과 부하단사이의 임피던스를 맞추어 주어야 최대의 전력이 전달된다. 무선전력전송 역시 RF Source와 송수신 코일간의 임피던스를 맞추어야 최대의 전력전달과 효율을 기대할 수 있다. 따라서 송수신 코일과 부하간에 임피던스 매칭은 필수적으로 필요하다. 매칭이 원할하지 않을 경우 RF Source에 반사전력이 반사되어 심각한 손실을 발생할 수 있으며, 수신부의 부하단에 최대로 전력이 전달되지 않으며 전체 시스템 효율이 나빠지게 된다. 임피던스 매칭회로 타입에는 여러가지 타입이 사용되는데 대표적으로 L type, T Type, ${\pi}$ type이 일반적으로 사용된다. 본 연구에서는 L type, T type, ${\pi}$ type 방식을 이용하여 각 타입별 매칭범위와 매칭특성에 대한 기초실험을 수행하였다.

• 한국동물위생학회지
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• 제14권2호
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• pp.110-120
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• 1991

28 porcine enteroviruses were isolated from 86 pig-feces of 9 swine farms located in south region, Chung-buk, from March to September 1990. Physico-chemical properties and pathogenicity of isolates were investigated. Results obtained throughout experiments are summarized as follows. According to the age, weanlings(40-90 days), sucklings(10-30 days) and adult pigs(6 months over) showed the isolation rate of 67%. 8% and 4%, respectively. By physico-chemical tests, YD-90/22, YD-90/43 and YD-90/64 strains were found to be ether, chloroform and PH stable. Nucleic acid test suggests the virus to have a DNA genome. Most of the Isolates were not evident of hemagglutinin using erythrocytes from various mammalian & avian. 22 strains among the isolates were shown CPE type I and the remainders were CPE type II. 3 strains among isolates of CPE type I strains were neutralized with high titers to serotype 2 antiserum. In the study on virus growth curve in PK-l5 cells, YD-90/22, YD-90/43 and YD-90/64 strains showed the maximum infectivity titers($10^{6.0}-l0^{6.5} TCID({50}ml$) at 4days post inoculation(PI). When 30 day-old commercial piglets were inoculated only intraoral route with the YD-90/22 strain at $10^{6.0} TCID_{50}ml,$ piglets not showed the symptoms. But piglets inoculated by intramuscle route, intraoral and intramuscle route after pretreat with dexamethasone(2.5mg /kg) for 5 days were shown the symptoms of anorexia, diarrhea, pyrexia and ataxia at 4th-6th days PI. The viral reisolation in the virus-inoculated piglets was examined from feces. The viruses were recovered intermittently from 2nd to 16th day PI and at 4th-6th day PI, all piglets excreted viruses.

• Journal of Power Electronics
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• 제14권5호
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• pp.1047-1056
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• 2014

In most grid-connected inverters (GCI) with an LCL filter, since the design of both the LCL filter and the controller is done separately, considerable tuning efforts have to be exerted when compared to inverters using an L filter. Consequently, an integrated co-design of the filter and the controller for an LCL-type GCI is proposed in this paper. The control strategy includes only a PI current controller and a proportional grid voltage feed-forward controller. The capacitor is removed from the LCL filer and the design procedure starts from an L-type GCI with a PI current controller. After the PI controller has been settled, the capacitor is added back to the filter. Hence, it introduces a resonance frequency, which is identified based on the crossover frequencies to accommodate the preset PI controller. Using the proposed co-design method, harmonic standards are satisfied and other practical constraints are met. Furthermore, the grid voltage feed-forward control can bring an inherent damping characteristic. In such a way, the good control performance offered by the original L-type GCI and the sharp harmonic attenuation offered by the latter designed LCL filter can be well integrated. Moreover, only the grid current and grid voltage are sensed. Simulation and experimental results verify the feasibility of the proposed design methodology.

• 대한수학회보
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• 제52권4호
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• pp.1253-1268
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• 2015

It is well known that an integral domain D is a UFD if and only if every nonzero prime ideal of D contains a nonzero principal prime. This is the so-called Kaplansky's theorem. In this paper, we give this type of characterizations of a graded PvMD (resp., G-GCD domain, GCD domain, $B{\acute{e}}zout$ domain, valuation domain, Krull domain, ${\pi}$-domain).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2120-2122
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• 2002

There are several types of control systems that use fuzzy logic controller as a essential system component. The majority of research work on fuzzy PID controller focuses on the conventional two-input PI or PD type controller. However, fuzzy PID controller design is a complex task due to the involvement of a large number of parameters in defining the fuzzy rule base. In this paper we combined conventional PI type and PD type fuzzy controller and set the initial parameters of this controller from the conventional PID controller gains obtained by Ziegler-Nichols tuning or other coarse tuning methods. After that, by replacing some of these parameters with sing1e neurons and making them to be adjusted by back-propagation learning algorithm we designed a neuro-fuzzy controller which showed good performance characteristics in both computer simulation and actual application.

• Molecules and Cells
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• 제20권2호
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• pp.241-246
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• 2005

PDK-1 activates PI3-kinase/Akt signaling and regulates fundamental cellular functions, such as growth and survival. NF-${\kappa}B$ is involved in the induction of a variety of cellular genes affecting immunity, inflammation and the resistance to apoptosis induced by some anti-cancer drugs. Even though the crucial involvement of the PI3-kinase/Akt pathway in the anti-apoptotic activation of NF-${\kappa}B$ is well known, the exact role of PDK-1 as well as PI3-kinase/Akt in NF-vactivation is not understood. Here we demonstrate that PDK-1 plays a pivotal role in transcriptional activation of NF-${\kappa}B$ by dissociating the transcriptional co-repressor HDAC1 from the p65 subunit of NF-${\kappa}B$. The association of CBP with p65 was not directly modulated by PDK-1 or by PI3-kinase. Etoposide activated NF-${\kappa}B$ through PI3-kinase/Akt, and the transcription activation domain (TAD) of p65 was further activated by wild-type PDK-1. Overexpression of a dominant negative PDK-1 mutant decreased etoposide-induced NF-${\kappa}B$ transcription and further down-regulated the ectopic HDAC1-mediated decrease in NF-${\kappa}B$ transcriptional activity. Thus activation of PDK-1 relieves the HDAC1-mediated repression of NF-${\kappa}B$ that may be related to basal as well as activated transcription by NF-${\kappa}B$. This effect may also explain the role of the PI3-kinase/PDK-1 pathway in the anti-apoptotic function of NF-${\kappa}B$ associated with the chemoresistance of cancer cells.

• BMB Reports
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• 제29권6호
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• pp.555-563
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• 1996

A membrane-bound phosphatidylinositol 4-kinase (PI 4-kinase) was separated in a sucrose gradient and solubilized with 1% Triton X-100 from mouse brain. The enzyme was purified 2,952-fold by various chromatographic techniques including DEAE-cellulose, PI-Sepharose and Sephacryl S-200 gel filtration. The molecular weight of PI 4-kinase was approximately 76 kDa by gel filtration and 70.8 kDa by SDS-polyacrylamide gel electrophoresis. The purified enzyme exhibited specific activity of 11.2 nmol/min/mg protein and pi value of 4.7. Kinetic analysis of the PI 4-kinase indicated apparent $K_m$, values of 190 ${\mu}M$ and 120 ${\mu}M$ for phosphatidylinositol and ATP, respectively. The maximal activity of this purified enzyme was observed at pH 7.4 at an incubation temperature of $37^{\circ}C$. The enzyme activity was significantly activated by $Mg^{2+}$, $Mn^{2+}$ and $Fe^{2+}$, and inhibited severely by $Ca^{2+}$. PI 4-kinase was proved to be pure in its immunoblot test by polyclonal antibody prepared from immunized rabbit sera. By this test, we were able to detect the existence of the same type of PI 4-kinase from other mouse organ tissues, such as liver, heart, kidney and spleen. Furthermore, similar immunoblot analysis with the same antisera recognized the different epitopes of PI 4-kinase proteins from various organs of rabbit, chinese hamster and rat.

• 대한화학회지
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• 제26권2호
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• pp.65-72
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• 1982

여러 형태의(n${\pi}$/m) 및 (n-${\sigma}^*$) 구조가 에너지에 미치는 구조적인 기여를 살펴보기 위하여 n-프로필아민, n-프로필아민 라디칼, trans-및 cis-에틸렌 디아민에 대한 STO-3G 수준의 계산을 수행하였다. 그 결과 (5${\pi}$/5)구조가 (4${\pi}$/4)구조는 각각 인력 및 반발의 비결합 상호작용을 나타내었으며 서로 부가관계를 가짐을 알았다. anti(n-${\sigma}^*$) 구조는 syn(n-${\sigma}^*$)구조보다 강한 hyperconjugation효과를 보이지만 anti(n-${\sigma}^*$)구조에서 강한 핵간 반발력을 가지기 때문에 결과적으로 불안정한 겉보기 효과를 나타내었다. 더우기 안정화${\pi}$ -비결합 (5${\pi}$/5)구조는 anti(${\pi}$-${\sigma}^*$)구조를, 불안정화 ${\pi}$-비결합(4${\pi}$/4)구조는 syn(n-${\sigma}^*$)구조를 수반하며 상호 보강적으로 작용함을 알았다. 또한 이러한 상호 보강성이 일반적인 성질임을 알았다. 끝으로 말단의 고립 전자쌍에 의한 through-bond 상호작용을 논의하였으며 이러한 상호작용으로 에너지 준위가 $n_+ = \frac{1}{\sqrt{2}}(n_1\;+\;n_2)$와 $n_-\;=\;\frac{1}{\sqrt{2}}(n_1\;-\;n_2)$로 갈라지는데 이때 고립 전자쌍의 간단한 overlap pattern으로 n_준위가 안정한 준위임을 알았다.

• 생명과학회지
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• 제31권8호
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• pp.729-735
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• 2021

제 2 형 당뇨병은 조직의 포도당 흡수 능력에 이상이 있을 때 발생하며, 인슐린에 의한 포도당 섭취와 신진대사는 혈당을 유지하는 기본 활동이며 포도당 섭취는 인슐린이 세포 표면의 수용체에 결합하여 시작되는 다양한 신호 단계를 거친다. 본 연구는 Ecklonia cava에서 분리된 활성 화합물 인 2,7-phloroglucinol-6,6-bieckol이 3T3-L1 지방 세포에서 인슐린 신호전달체계에 따른 포도당 흡수 증가에 미치는 영향에 대한 것이다. 2,7-phloroglucinol-6,6-bieckol 은 3T3-L1 지방 세포에서 농도의존적으로 GLUT4의 발현을 증가시켜 원형질막에서의 glucose uptake 를 증가시켰다. 이는 인슐린 신호 전달 경로에서 2,7-phloroglucinol-6,6-bieckol 에 의한 IRS-1, AKT의 인산화 및 PI3K 활성화에 의한 것이다. PHB는 또한 AMPK 인산화와 활성화를 자극했다. 2,7-phloroglucinol-6,6-bieckol에 의한 PI3K/AKT 및 AMPK 경로의 인산화 및 활성화는 wortmannin (PI3K 억제제) 및 화합물 C (AMPK 억제제)를 사용하여 확인하였다. 본 연구에서 2,7-phloroglucinol-6,6-bieckol 이 3T3-L1 지방 세포에서 PI3K 및 AMPK 경로를 통해 원형질막으로의 GLUT4 전위를 촉진함으로써 포도당 흡수를 증가시킬 수 있음을 나타내었다. 이러한 결과는 2,7-phloroglucinol-6,6-bieckol 가 인슐린 감수성을 개선하는 데 도움이 될 수 있음을 시사한다.

• Bulletin of the Korean Chemical Society
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• 제16권8호
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• pp.764-768
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• 1995