• Title/Summary/Keyword: U-factor

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On the Summability of Infinite Series and Hüseyin Bor (무한급수의 총합 가능성과 후세인 보르에 관하여)

  • Lee, Jung Oh
    • Journal for History of Mathematics
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    • v.30 no.6
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    • pp.353-365
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    • 2017
  • In general, there is summability among the mathematical tools that are the criterion for the convergence of infinite series. Many authors have studied on the summability of infinite series, the summability of Fourier series and the summability factors. Especially, $H{\ddot{u}}seyin$ Bor had published his important results on these topics from the beginning of 1980 to the end of 1990. In this paper, we investigate the minor academic genealogy of teachers and pupils from Fourier to $H{\ddot{u}}seyin$ Bor in section 2. We introduce the $H{\ddot{u}}seyin$ Bor's major results of the summability for infinite series from 1983 to 1997 in section 3. In conclusion, we summarize his research characteristics and significance on the summability of infinite series. Also, we present the diagrams of $H{\ddot{u}}seyin$ Bor's minor academic genealogy from Fourier to $H{\ddot{u}}seyin$ Bor and minor research lineage on the summability of infinite series.

Interpretation of Empirical Cone Factors for Determining Undrained Strength (비배수강도 결정을 위한 콘 지수 연구)

  • Kim, Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.11
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    • pp.3296-3301
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    • 2009
  • The results of PCPT(Pezocone Penetration Test) are widely used for the estimation of the undrained shear strength, for which the empirical cone factors($N_{kt}$, $N_{ke}$, $N_{{\Delta}u}$) need to be obtained at each site. In this study, the cone factors were estimated, for the soils at Bookmyun area in Changwon city, using the undrained shear strengths from the unconfined and UU triaxial compression tests. The parametric studies with plastic index and pore water pressure ratio were performed as well. $N_{kt}$, $N_{ke}$ and $N_{{\Delta}u}$ were estimated in the ranges of 8~40, 7~37, and 1~26 respectively. It was observed that there is a relationship between the cone factors, specially $N_{{\Delta}u}$, and the pore pressure ratio.

A Study on Strength Characteristics of Yieldable Steel Arch Supports (가축성 강재 지보의 강도특성에 관한 연구)

  • 김종우
    • Tunnel and Underground Space
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    • v.8 no.4
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    • pp.261-274
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    • 1998
  • The brief results of laboratory and field tests of yieldable steel arches are represented. The test supports were fabricated with three U-sectional beams which are 25.8 kg/m of Glocken profile. The structural analyses of semi-circular and arch supports were conducted to find out shape factor of U beam to be 1.35 and the location of 2nd plastic hinges. Load capacity of arch supports under crown loading were examined as a function of leg length. Yieldable characheristics of test supports were investigated with various bolting torque of connection part. Determination method of bolting torque were also studied. Finally, test supports were installed in-situ with torque of 21 kg .m, which showed a typical yielding procedure.

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Urokinase Plasminogen Activator Receptor Gene Expression and Clinico-Pathologic Feature in Gastric Cancer Patients (위암 환자의 Urokinase Plasminogen Activator Receptor 유전자의 발현양상)

  • Kim Yong Gil;Lee Kyung Hee;Kim Min Kyung;Lee Jae Lyun;Hyun Myung Sue;Kim Sang Hun;Kim Hee Sun
    • Journal of Gastric Cancer
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    • v.4 no.4
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    • pp.207-212
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    • 2004
  • Purpose: Invasion and metastasis in solid tumors require the action of tumor-associated proteases. The serine protease urokinase-type plasminogen (uPA) and receptor (uPAR) appear to have a major function in these processes. Expression of the uPAR is elevated in breast and colon carcinomas, and this is often associated with invasiveness and poor prognosis. The purpose of this study was to determine whether the expression of the uPAR gene correlates with clinico-pathological parameters in human gastric carcinomas. Materials and Methods: We examined the expression of uPAR mRNA by using northern blot analysis and RT-PCR in 35 gastric carcinomas and the surrounding normal mucosa. Macroscopic and histopathological tumor findings and survival rates were obtained from the patient records and from endoscopic, surgical, and pathological reports. Results: The expression of uPAR and was higher in most neoplasms than in the corresponding normal mucosal tissue. uPAR mRNA expression in tumors correlated well with lymph-node metastasis (P<0.02) and tumor stage (P<0.01). The survival rate of patients with tumors displaying high uPAR expression levels was significantly lower (P<0.04) than that of patients without uPAR expression, but IL-8 showed only the tendency of survival difference. Conclusion: These results suggest that uPAR may be an important prognostic factor in human gastric carcinomas.

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The Effect of Oxygen Transfer Rate on the Nebramycin Factor 5' Activity and Component Ratio in Streptoalloteichus hindustanus Fermentation. (Streptoalloteichus hindustanus 발효시 Nebramycin Factor 5' 역가 및 구성비율에 대한 산소전달속도의 영향)

  • 김정근;이병규;노용택
    • Microbiology and Biotechnology Letters
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    • v.31 no.4
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    • pp.395-399
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    • 2003
  • Nebramycin is a complex of aminocyclitol compounds that is produced by aerobic culture in fermentation process. The major antibiotic factors produced by Streptoalloteichus hindustanus are nebramycin factor 2, 4, 5'and kanamycin A. A mutant was selected, producing nebramycin factor 5' activity 16.4 times higher than parent strain by microbiological assay using Pseudomonas aeruginosa CH-U34AF. The component ratio of nebramycin factor 5' was dramatically increased from 34% to 70% by the optimization of fermentation condition. It was found that the component ratio of nebramycin factor 5' in fermentation was especially affected by the oxygen transfer rate. Optimum oxygen transfer rate for maximal nebramycin factor 5' productivity and ratio during S. hindustanus fermentation was elucidated to $0.50 mMO_2$/min.

Analysis of the Reason for ROK's Foreign Strategy Adjustment: The growing threat from DPRK under the U.S.-China strategic competition and its profound influences on the security situation in Northeast Asia (韩国对外战略调整的原因分析-美中战略竞争下不断增加的北韩威胁对东北亚安全局势带来的深远影响)

  • Dongchan Kim;Jangwon Lee
    • Analyses & Alternatives
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    • v.7 no.3
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    • pp.115-144
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    • 2023
  • Under the Trump administration, the U.S. has made clear that "China is America's strategic competitor, revisionist power and a major challenge to America's prosperity and security." The Biden administration has largely inherited this perception of China. China has also responded without backing down. Therefore, the U.S.-China strategic competition has become the most important background factor in the international system and has a great impact on the security situation in Northeast Asia. Nevertheless, if you look at the recent process of establishing trilateral security cooperation among ROK, the U.S. and Japan, we can find that ROK's foreign strategy adjustment has played a key role. This is because establishing trilateral security cooperation among ROK, the U.S. and Japan depends on improving ROK-Japan relations. And the Yoon Suk Yeol government is pushing for rapid improvement in ROK-Japan relations regardless of domestic political constraints. The trilateral summit at Camp David laid the groundwork for future cooperation among ROK, the U.S. and Japan in security and other broader areas. China is strongly dissatisfied with the formation of trilateral security cooperation among ROK, the U.S. and Japan. However, this paper argues that although ROK agrees to form trilateral security cooperation with the U.S. and Japan, ROK's strategic objectives are not exactly the same as those of the U.S. and Japan. For example, looking back at the development of the U.S.-Japan alliance after the end of the Cold War, both the U.S. and Japan share similar views and perceptions of China's rise. The real goal of the strengthening of the U.S.-Japan alliance in recent years is also how to cope with China's rise. On the other hand, ROK's previous administrations have been negative about trilateral security cooperation with the U.S. and Japan. This is because ROK's main strategic goal is to reduce or eliminate threats from DPRK rather than respond to China. Faced with increasing DPRK's provocations and threats, more than half of South Koreans are in favor of reinforcing trilateral security cooperation with the U.S. and Japan to contain or mitigate threats from DPRK. As a result, if North Korea's nuclear and missile threats to ROK continue, then ROK's foreign strategy is likely to be to strengthen trilateral security cooperation between the U.S. and Japan to ensure its own safety and survival. If China wants to reduce the strategic pressure from the trilateral security cooperation among ROK, the U.S. and Japan, the best way is to reduce DPRK's provocations and threats to ROK and play a more substantive role in getting DPRK to give up its nuclear program.

Influence of Modelling Approaches of Diffusion Coefficients on Atmospheric Dispersion Factors (확산계수의 모델링방법이 대기확산인자에 미치는 영향)

  • Hwang, Won Tae;Kim, Eun Han;Jeong, Hae Sun;Jeong, Hyo Joon;Han, Moon Hee
    • Journal of Radiation Protection and Research
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    • v.38 no.2
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    • pp.60-67
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    • 2013
  • A diffusion coefficient is an important parameter in the prediction of atmospheric dispersion using a Gaussian plume model, and its modelling approach varies. In this study, dispersion coefficients recommended by the U. S. Nuclear Regulatory Commission's (U. S. NRC's) regulatory guide and the Canadian Nuclear Safety Commission's (CNSC's) regulatory guide, and used in probabilistic accident consequence analysis codes MACCS and MACCS2 have been investigated. Based on the atmospheric dispersion model for a hypothetical accidental release recommended by the U. S. NRC, its influence to atmospheric dispersion factor was discussed. It was found that diffusion coefficients are basically predicted from a Pasquill- Gifford curve, but various curve fitting equations are recommended or used. A lateral dispersion coefficient is corrected with consideration for the additional spread due to plume meandering in all models, however its modelling approach showed a distinctive difference. Moreover, a vertical dispersion coefficient is corrected with consideration for the additional plume spread due to surface roughness in all models, except for the U. S. NRC's recommendation. For a specified surface roughness, the atmospheric dispersion factors showed differences up to approximately 4 times depending on the modelling approach of a dispersion coefficient. For the same model, the atmospheric dispersion factors showed differences by 2 to 3 times depending on surface roughness.

A BIFUNCTIONAL UTILITY CONNECTED PHOTOVOLTAIC SYSTEM WITH POWER FACTOR CORRECTION AND U.P.S. FACILITY

  • Kim. S.;Yoo, Gwonjong;Song, Jinsoo
    • Proceedings of the KIPE Conference
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    • 1996.06a
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    • pp.103-108
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    • 1996
  • In this paper, a novel utility connected photovoltaic power generation system with unity power factor and uninterruptable power system facility and its control strategy are proposed. The proposed photovoltaic(PV) system is connected in parallel between utility and load. The PV system provides an uninterruptable voltage to load, a maximum power tracking to solar array, and power factor correction to the utility. The proposed system has the following advantages compared with the conventional utility connected PV system. 1. Harmonic elimination Function 2. Feeding the photovoltaic energy to the utility 3. Providing the uninterruptible power source along battery to the load In case that the photovoltaic array system is on the poor power generation, the battery and capacitor of the PV system are charged by three phase utility source and the inverter in the PV system only provides the reactive current to eliminate the harmonic current exited on the utility. In the normal operation mode, the PV system supplies active power to load and reactive power to utility in order to maintain the unity power factor and to regulate ac load voltage.

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Evaluation of Response Modification Factors for Shear Wall Apartment Building (벽식 APT의 반응수정계수 추정에 관한 연구)

  • 송정원;송진규;이수곤
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.859-864
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    • 2001
  • For earthquake resistance design, a response modification factor is used to reduce the design strength and it reflects ductility, reserve strength, redundancy and damping effect. But this factor has not theoretical basis. In this study, two response modification factors are compared and analyzed for shear wall apartment building.; the one is introduced by ATC-19 Procedures, the other is suggested FEMA-273 and ATC-40 through nonlinear static analysis. For the results, ATC-19 procedure gives a reasonable estimation to R factor. But $R_{u}$ by using FEAM-273 and ATC-40 methods is estimated so small in case of a minor or moderate earthquake region. Due to this fact, response modification factor is smaller than suggested load criterion 3.0. So, it needs to decrease wall volume and reduce the global strength and system stiffness for proper ductile behavior matching to domestic load criterion.

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Calculation of stress intensity factor considering out-of-plane bending for a patched crack with finite thickness (유한두께를 가지는 보강된 균열평판에 대한 면외굽힘을 고려한 응력강도계수 계산)

  • Kim, Jong-Ho;Lee, Soon-Bok
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.165-169
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    • 2000
  • A simple method was suggested to calculate the stress intensity factor for a one-sided patched crack with finite thickness. To consider out-of-plane bending effect resulting from the load-path eccentricity, the spring constant as a function of the through-thickness coordinate z was calculated from the stress distribution in the un-cracked plate, ${\sigma}_{yy}(y=0,\;z)$, and the displacement for the representative single strip Joint, $u_y(y=0,\;z)$. The stress Intensity factors were obtained using Rose's asymptotic solution approach and compared with the finite element results. In short crack region, two results had a little difference. However, two results were almost same in long crack region. On the other hand, the stress intensity factor using plane stress assumption was more similar to finite element result than plane strain condition.

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