• Title/Summary/Keyword: Sorensen

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Sorensen's Sorites and the Vagueness of 'Vague' (소렌센의 더미와 '모호함'의 모호함)

  • Lee, Jin-Hee
    • Korean Journal of Logic
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    • v.13 no.2
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    • pp.117-134
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    • 2010
  • In this paper, I attempted to show that 'Sorensen's Sorites' is not a successful argument for the vagueness of 'vague'. There are a lot of debates about it, but the central issue is whether Sorensen's Sorites is just small sorites; whether the vagueness certified by Sorensen's Sorites is just the vagueness of 'small'. Deas and Hull thought it was and rejected Sorensen's proof based on his sorites. But their rejection was rebutted by Varzi. The basis of his argument is that the subject of Sorensen's sentences - 'n-small' is vague - is not used but mentioned. I tried to reply on behalf of Deas and Hull and to show that the predicate 'vague' has not any effect on determining the truth value of "'n-small' is vague." Then it can be removed from the sentence. Of course I approve 'vague' is a homological term. What I do not agree with is only Sorensen's argument.

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Paradox of Sorensen Sorites (소렌센 더미 역설)

  • Lee, Jinhee
    • Korean Journal of Logic
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    • v.20 no.3
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    • pp.335-366
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    • 2017
  • Sorensen proved that 'vague' is vague through a sorites paradox that he presented. I will show that his sorites paradox satisfies the conditions for a sorites paradox and does not satisfy those conditions. So we will face a new paradox which exemplifies inconsistency of conditions for a sorites paradox. But those conditions include a principle which says when two cases are close enough, there will be no change in truth value. It represents an essential feature of vagueness. Therefore the paradox I will present in this article is not only shows inconsistency of conditions for a sorites paradox but also shows inconsistency of vagueness itself.

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Spectral Electromyographic Fatigue Analysis of Back Muscles in Healthy Adult Men and Women During Sorensen Test (근전도를 이용한 Sorensen 검사시 성인남녀 등 근육의 근피로도 분석)

  • Lee, Mi-Seon;Kim, Tae-Young
    • Physical Therapy Korea
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    • v.5 no.3
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    • pp.63-71
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    • 1998
  • Trunk holding test (Sorensen test) appear to have more value than strength test in prediction the occurrence of low back pain. Electromyographic activity of trunk extensor muscles during these test may provide clues to the etiology of neuromuscular-based low back pain. This study investigated the difference in back muscle endurance between healthy adult men and women using surface electromyographic (EMG) power spectral analysis. Thirty hea1thy subjects (15 men and 15 women) performed an unsupported trunk holding test for 60 seconds. Recording surface electrodes were placed over the erector spinae medially and laterally at vertebral levels of $L_1$ and $L_5$. Slope of total frequency was evaluated using the MP100WSW Fast Fourier Transform spectrum analysis program. The slopes of all indices of back muscle fatigue, except right $L_5$, were significantly steeper in men than in women (p<0.05). Our results indicated that the trunk holding test using EMG power spectral analysis of erector spinae muscles is useful for the evaluation of fatigue rate of these muscles. Our results also showed a higher muscle endurance in healthy adult women than in men.

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Numerical Simulation of One-Dimensional Madsen-Sørensen Extended Boussinesq Equations Using Crowhurst-Zhenquan Scheme (Crowhurst-Zhenquan 방법을 이용한 1차원 Madsen-Sørensen 확장형 Boussinesq 방정식의 수치 시뮬레이션)

  • Kang, Sangmuk;Park, Jinsoo;Jang, Taek Soo
    • Journal of Ocean Engineering and Technology
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    • v.31 no.5
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    • pp.346-351
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    • 2017
  • The aim of this paper is to apply the Crowhurst-Zhenquan scheme to one-dimensional Madsen-Sørensen extended Boussinesq equations. In order to verify the application of the aforementioned scheme, the propagation of solitary waves was simulated for two different cases of submarine topography; e.g., a plane beach and submerged breakwater. The simulated results are compared to the results of recent studies and show favorable agreement. The behavior of progressive waves is also investigated.

Modifying a Back Endurance Test for Examining Erector Spine Muscles by Adding Lateral Trunk Bending and Trunk Rotation

  • Park, Se-Yeon;Park, Du-Jin
    • PNF and Movement
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    • v.15 no.3
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    • pp.381-387
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    • 2017
  • Purpose: Although some studies indicate that the Sorensen test may not be used to examine back muscles such as the erector spinae, alternatives to the back-extension test are rarely suggested. Therefore, the purpose of the present study was to investigate an effective way to stimulate the erector spinae muscles by adding a component of trunk rotation and lateral bending to general back extensions. Methods: A total of 18 healthy, physically active participants performed simple trunk extension, extension with trunk rotation, and extension with lateral bending. Surface electromyography responses of the latissimus dorsi, thoracic, and lumbar levels of the erector spinae; the gluteus maximus; and the biceps femoris muscles were investigated during these 3 conditions of modified back extension tests. Results: The simple trunk extension exercise caused significant increases in activity of the gluteus maximus and biceps femoris muscles as compared to the extension with rotation and lateral bending exercises. The extension with trunk rotation exercise showed significantly greater activation in the thoracic and lumbar levels of the erector spinae and in the latissimus dorsi as compared to the other exercises. The index measuring subjective difficulty was significantly lower in the simple trunk extension exercise as compared to the extension with trunk rotation and extension with lateral bending exercises. Conclusion: The present study suggests that extension with trunk rotation has the advantage of stimulating the para-spinal muscles, while simple trunk extension may not be adequate to selectively simulate the para-spinal muscles but may be appropriate for examining global trunk extensors.

서울지역 열병합발전 지역난방 타당성 조사

  • 채재우;성재석
    • Journal of the KSME
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    • v.22 no.3
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    • pp.223-232
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    • 1982
  • 우리나라에 있어서 열병합 발전 지역난방이 1960 년대에 거론되어, 당인리 화력발전소의 폐열을 여의도 지역난방으로 이용하자는 이야기가 있었다. 그러나 이러한 "이야기"가 경제성이 있는 것 으로 판단된 것은 적극적인 연구사업인 1978 년도 과학기술원의 반월공단에 대한 타당성 검토와 여의도 강남지역의 타당성 검토를 통하여 비롯되었다. 이러한 일련의 연구검토를 토대로 우리 나라 환경에 맞는 기술의 국내 도입을 위하여 이 분야에 오랜 전통을 갖는 해외 전문용역회사 BRUNN '||'&'||' SORENSEN A/S와 한국 동력자원연구소 에너지분소가 공동으로 국내 열병합발 전지역 난방 타당성 조사사업을 1980. 9-1981.7까지 수행하였다. 본 타당성 조사의 기술 및 경 제성 분석 과정과 결과를 서술하고 향후 추진방향을 제시코자 한다.다.

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The Relationship between the Soil Seed Bank and Above-ground Vegetation in a Sandy Floodplain, South Korea

  • Cho, Hyung-Jin;Jin, Seung-Nam;Lee, Hyohyemi;Marrs, Rob H.;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.5 no.3
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    • pp.145-155
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    • 2018
  • In a monsoonal climate, the soil seed bank can play an important role in plant regeneration after the severe annual floods that disturb above-ground vegetation within the riparian zone. To investigate the relationship between the soil seed bank and vegetation, we measured the species composition of the soil seed bank and the extant above-ground vegetation in six major plant communities (Artemisia selengensis, Miscanthus sacchariflorus, Persicaria nodosa, Phalaris arundinacea, Phragmites japonica, and Rorippa palustris) in the Cheongmicheon Stream, Korea. A total of 21 species germinated from the floodplain soil seed banks. The most diverse seed bank (21 species) was found in the A. selengensis community, wheres the lowest number of species was found in the R. palustris community (2 species). Most soil seed banks were composed of annuals (90%), exceptions being Rumex crispus and Artemisia princeps, which are perennial ruderals. The similarity of species composition between the soil seed bank and above-ground vegetation was low with Sorensen's similarity indices averaging 29% (range 12 - 42%). Crucially, existing dominant perennials of the extant vegetation including A. selengensis, M. sacchariflorus, P. japonica and P. arundinacea were absent from the soil seed bank. In conclusion, the soil seed banks of the floodplains of the Cheongmicheon Stream were mainly composed of viable seeds of ruderal plants, which could germinate rapidly after severe flood disturbance. The soil seed bank may, therefore, be useful for the restoration of the early succession stages of riparian vegetation after flood disturbances.

Advanced Tools for Modeling, Design and Optimization of Wind Turbine Systems

  • Iov Florin;Hansen Anca Daniela;Jauch Clemens;Sorensen Poul;Blaabjerg Frede
    • Journal of Power Electronics
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    • v.5 no.2
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    • pp.83-98
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    • 2005
  • As wind turbine technology and control has advanced over the last decade, this has led to a high penetration of wind turbines into the power system. Whether it be for a large wind turbine or an offshore wind farm with hundreds of MW power capacity, the electrical system has become more and more important in controlling the interaction between the mechanical system of the wind turbine and the main power system. The presence of power electronics in wind turbines improves their controllability with respect not only to its mechanical loads but also to its power quality. This paper presents an overview of a developed simulation platform for the modeling, design and optimization of wind turbines. The ability to simulate the dynamic behavior of wind turbines and the wind turbine grid interaction using four simulation tools (Matlab, Saber, DIgSILENT and HAWC) is investigated, improved and extended.

A Study on the Absorption Mechanism of Drugs through Biomembranes

  • Lee, Chi-Ho;Kim, Heun-Jo
    • Archives of Pharmacal Research
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    • v.17 no.3
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    • pp.182-189
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    • 1994
  • The effect of lipophilicity on the mechanisms of drug absorption through biomembranes was investigated empolying HPLC system and the fluorescence technique. Human erythrocyte ghost membranes were used as a model biomembrane. A series of four parabens (methyl, ethyl, rpopyl, and butyl) and p-hydroxybenzoic acid were used as the model drugs for lipophilicities and their partition coefficients were measured in Sorensen's phosphate buffer solution (pH 5)/octanol system. Absorption amount of parabens through erythrocyte ghost membranes increased with an increase of lipophilicity resulted from the addition of methylene group to the n-alkyl chain of parabens. And the effect of parabens on the fluidity of ghost membrane also increased with an increase of their lipophilicities.

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