• 제목/요약/키워드: F and $F^{+}$-Center

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전자소자에서의 $\frac {1}{f}$잡음에 관한 연구 (A Study on the Theory of $\frac {1}{f}$ Noise in Electronic Devies)

  • 송명호
    • 한국통신학회논문지
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    • 제3권1호
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    • pp.18-25
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    • 1978
  • 반도체 소자에서 생기는 1/f 형의 잡음의 근원이 무엇인가에 대해 지금까지 여러 이론이 나왔다. 그중에도 Mcwhorter's Surface model이 대표적인 이론이었다. 그러나 Hooge는 이론에 반기를 들고 나왔다. Hooge의 이론에 의하면 thermo cell이나 Concentration cell에서의 1/f-형의 잡음이 표면효과(surface effect)가 아니라는 것이다. 본 논문에서는 이 두 대표적인 이론을 종합검토할 수 있는 Langenvin type의 Boltzmann transport equation에 입각하여 새로운 일반이론을 세웠다. 본 논문에서는 N형 채널을 갖고 있는 금속산화물반도체 전계효과 트랜지스터에서 단일준의 Shockley-Read-Hall recombination center에 의한 단락회로에서 드레인의 1/f-형 잡음스펙트럼을 계산하기 위해 시간에 따라 변화하는 양을 포함시키므로써 각 에너지대의 케리어에 대해 준-페르미준위를 정의할 수 없다고 가정했으므로, 1/f-형의 잡음은 다수케리어 효과에 기인한다고 가정했다. 이러한 가정하에서 유도된 1/f-형의 잡음은 금속산화물반도체 전계효과 트랜지스터에서 1/f-형의 잡음에 중요한 요인들을 모두 보여주었다. : 적주파에서 플렛티유를 나타내지 않았고 채널의 면적 A와 드레인 바이어스 전압 V에 비례하고 체널의 길이 L에 반비례한다. 본 논문의 모델에서는 1/f-응답에서 1/f2에 대한 잡음스트럼의 전이주파수와 P-n 합다이오우드의 surfact center에 관계되는 완화시간(relaxation time)에 대응하는 주파수 사이를 구별하여 설명할 수 있었다. 본 논문의 결과에서 1/f-형 잡음스펙트럼은 격자산란이 주원인이 된다. 금속산화물반도체 전계효과 트랜지스터를 살펴보면 격자산란이 주로 표면에서 일어나기 때문에 1/f-형 잡음이 표면효과라고 말할 수 있다.

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상대압 용량성 압력센서의 제작 (Fabrication of Relative-type Capacitive Pressure Sensor)

  • 서희돈;임근배;최세곤
    • 전자공학회논문지A
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    • 제30A권7호
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    • pp.82-88
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    • 1993
  • This paper describes fabrication of relative type capacitive pressure sensor to be in great demand for many fields. The fabricated sensor consists of two parts` a sensing diaphragm and a pyrox glass cover. The sensor size is 4.5${\times}3.4mm$^{2})$ and 400$\mu$m thick. To improve the nonlinearity, this sensor is designed a rectangular silicon diaphragm with a center boss structure, and in order to improve the temperature characteristics of the sensor in a packaging process, the sensing element is mounted on the pyrex glass support. Some suggestions toward the design and fabrication of improved sensors have been presented. The zero pressure capacitance, Co of sensor is 26.57pF, and the change of capacitance, ${\Delta}$C is 1.55pF from 0Kgf/Cm$^{2}$ to 1Kgf/Cm$^{2}$ at room temperature. The nonlinearity of the sensor output with center boss diaphragm is 1.29%F.S., and thermal zero shift and thermal sensitivity shift is less than 1.43%F.S./$^{\circ}C$and 0.14% F.S./$^{\circ}C$, respectively.

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Molecular Authentication of Magnoliae Flos Using Robust SNP Marker Base on trnL-F and ndhF Region

  • Kim, Min-Kyeoung;Noh, Jong-Hun;Yan, Deok-Chun;Lee, Sanghun;Lee, Hee-Nyeong;Jin, Chi-Gyu
    • 한국자원식물학회지
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    • 제28권3호
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    • pp.341-349
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    • 2015
  • Magnoliae Flos (Sini in Korean) is one of the most important oriental medicinal plants. In the Korean Herbal Pharmacopeia, the bud of the all species in Manolia denudate and Manolia genus were regarded as the botanical sources for ‘Sini’. Most the dried bud of Manolia denudata, Manolia biondii and Manolia sprengeri were used as ‘Xin-yi’ in China. Therefore, the purpose of this study was to determine and compare the ‘Magnolia’ species, four species including Manolia denudata, M. biondii, M. liliiflora and M. Kobus were analysis of sequencing data revealed DNA polymorphisms. The based on tRNA coding leucine/phenylalanine (trnL-F) and NADH-plastoquinone oxidoreductase subunit 5 (ndhF) sequences in chloroplast DNA. For the identification of ‘Magnolia’ species, polymerase chain reaction (PCR) analysis of chloroplast DNA regions such as ndhF have proven an appropriate method. A single nucleotide polymorphism (SNP) has been identified between genuine “Sini” and their fraudulent and misuse. Specific PCR primers were designed from this polymorphic site within the sequence data, and were used to detect true plants via multiplex PCR.

진폐가족의 사회적지지 특성 (The Perceived Social Support of the Family with Pneumoconiosis Patient)

  • 박영미;이성은
    • 재활간호학회지
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    • 제7권2호
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    • pp.220-230
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    • 2004
  • Purpose: The study has planned to find out the perceived social support of the families with pneumoconiosis patients. Method: The subjects of the study were the 300 family care givers of the pneumoconiosis patients who were hospitalized in Taeback, Donghae and Jeongsun Occupational Medical Center. The Social Support Survey Instrument developed by Park(1985) was adopted. Results: The Direct Perceived Supports showed statistically differences by the age(F=1.70 p=0.01) and the state of the disease(F=3.09 p=0.027) of the patients. The Health Situation Centered Support was different by the marietal situation(F=2.29 p=0.48) of the pneumoconiosis patients. The Indirect Perceived Supports were statistically different by sex(t=3.76 p=0.043) and relation with the patient (F=2.49 p=0.048), group joining(t=3.79 p=0.042) of the family care givers. The DPSs were statistically different by family income(F=2.25 p=0.025), family authority(F=2.81 p=0.031) and health insurance status(F=2.13 p=0.026). Recommendation: It is recommended to develop an active social support program at the pneumoconiosis care centers for the middle aged female family care givers of the pneumoconiosis patients with the support of Ministry of Labor, Ministry of Health and Welfare and other NGOs of pneumoconiosis.

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두경부 종양에서 $^{18}F-FDG$ PET의 임상이용 (Clinical Application of $^{18}F-FDG$ PET in Head and Neck Cancer)

  • 김재승;배진호
    • Nuclear Medicine and Molecular Imaging
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    • 제42권sup1호
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    • pp.6-13
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    • 2008
  • Head and neck cancer is the sixth most common type of human cancer worldwide. Squamous cell carcinoma is the most common cancer of the head and neck. Since $^{18}F-FDG$ PET is very sensitive to detecting squamous cell carcinoma, it has been widely used in patients with head and neck cancers for initial staging, management of recurrent cancers, and therapeutic monitoring. According to clinical research data, $^{18}F-FDG$ PET is expected to be a very helpful diagnostic tool in the management of head and neck cancer.

Identification of Potential Corynebacterium ammoniagenes Purine Gene Regulators Using the pur-lacZ Reporter in Escherichia coli

  • HAN , RI-NA;CHO, ICK-HYUN;CHUNG, SUNG-OH;HAN, JONG-KWON;LEE, JIN-HOO;KIM, SOO-KI;CHOI, KANG-YELL
    • Journal of Microbiology and Biotechnology
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    • 제14권6호
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    • pp.1249-1255
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    • 2004
  • This study has developed Corynebacterium ammoniagenes (c. ammoniagenes) purine gene transcriptional reporters (purF-lacZ and purE-lacZ) that function in Escherichia coli (E. coli) DH5a. After transformation of a C. ammoniagenes gDNA library into E. coli cells harboring either purF-lacZ or purE-lacZ, C. ammoniagenes clones were obtained that repress purF-lacZ and purE-lacZ gene expression. The potential purE and purF regulatory genes are homologous to the genes encoding transcription regulators, the regulatory subunit of RNA polymerase, and genes for purine nucleotide biosynthesis of various bacteria. The C. ammoniagenes purE-lacZ and purF-lacZ reporters were repressed by adenine and guanine within E. coli, indicating similarity in the regulatory mechanism of purine biosynthesis in C. ammoniagenes and E. coli. Gene regulation of pur-lacZ by adenine and guanine was partly abolished in cells expressing potential purine regulatory genes, indicating functionality of the purine gene regulators in repression of purE-lacZ and purF-lacZ. The purE-lacZ and purF-lacZ reporters can be used for the screening of genes involved in the regulation of the de novo synthesis of the purine nucleotides.

The Branch Extracts of Vaccinium oldhamii Stimulate Melanin Synthesis Through Activation of Tyrosinase Activity in B16F10 Melanoma Cells

  • Park, Su Bin;Kim, Ha Na;Kim, Jeong Dong;Park, Gwang Hun;Son, Ho-Jun;Eo, Hyun Ji;Song, Jeong Ho;Jeong, Hyung Jin;Jeong, Jin Boo
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 추계학술대회
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    • pp.95-95
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    • 2018
  • In this study, we investigated the effect of branch extracts from Vaccinium oldhamii (VOB) on melanin synthesis in B16F10 cells. VOB promoted melanin production in absence or presence of ${\alpha}$-melanocyte-stimulating hormone (${\alpha}-MSH$) in B16F10 cells. However, VOB did not affect the expression of tyrosinase and TRP-1 associated with melanin synthesis at the mRNA and protein level in B16F10. But, VOB decreased TRP-2 protein level and induced tyrosinase activation in B16F10 cells. Inhibition of tyrosinase activity and tyrosinase knockdown attenuated VOB-mediated melanin synthesis. In conclusion, it is thought that VOB may stimulate melanin synthesis through activating tyrosinase activity.

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Scant Extracellular NAD Cleaving Activity of Human Neutrophils is Down-Regulated by fMLP via FPRL1

  • Hasan, Md. Ashraful;Sultan, Md. Tipu;Ahn, Won-Gyun;Kim, Yeon-Ja;Jang, Ji-Hye;Hong, Chang-Won;Song, Dong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • 제18권6호
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    • pp.497-502
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    • 2014
  • Extracellular nicotinamide adenine dinucleotide (NAD) cleaving activity of a particular cell type determines the rate of the degradation of extracellular NAD with formation of metabolites in the vicinity of the plasma membrane, which has important physiological consequences. It is yet to be elucidated whether intact human neutrophils have any extracellular NAD cleaving activity. In this study, with a simple fluorometric assay utilizing $1,N^6$-ethenoadenine dinucleotide (etheno-NAD) as the substrate, we have shown that intact peripheral human neutrophils have scant extracellular etheno-NAD cleaving activity, which is much less than that of mouse bone marrow neutrophils, mouse peripheral neutrophils, human monocytes and lymphocytes. With high performance liquid chromatography (HPLC), we have identified that ADP-ribose (ADPR) is the major extracellular metabolite of NAD degradation by intact human neutrophils. The scant extracellular etheno-NAD cleaving activity is decreased further by N-formyl-methionine-leucine-phenylalanine (fMLP), a chemoattractant for neutrophils. The fMLP-mediated decrease in the extracellular etheno-NAD cleaving activity is reversed by WRW4, a potent FPRL1 antagonist. These findings show that a much less extracellular etheno-NAD cleaving activity of intact human neutrophils compared to other immune cell types is down-regulated by fMLP via a low affinity fMLP receptor FPRL1.

1/f Noise Characteristics of Sub-100 nm MOS Transistors

  • Lee, Jeong-Hyun;Kim, Sang-Yun;Cho, Il-Hyun;Hwang, Sung-Bo;Lee, Jong-Ho
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제6권1호
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    • pp.38-42
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    • 2006
  • We report 1/f noise PSD(Power Spectrum Density) of sub-100 nm MOSFETs as a function of various parameters such as HCS (Hot Carrier Stress), bias condition, temperature, device size and types of MOSFETs. The noise spectra of sub-100 nm devices showed Lorentzian-like noise spectra. We could check roughly the position of a dominant noise source by changing $V_{DS}$. With increasing measurement temperature, the 1/f noise PSD of 50 nm PMOS device decreases, but there is no decrease in the noise of NMOS device. RTN (Random Telegraph Noise) was measured from the device that shows clearly a Lorentzian-like noise spectrum in 1/f noise spectrum.