• 논리연구
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• 제13권2호
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• pp.117-134
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• 2010

'모호함'의 모호성을 정당화하는 소렌센의 논증은, '모호함'에 대한 직관적 이해를 체계적으로 정당화한다는 측면에서 매우 중요한 의미를 갖는다. 그러나 필자는 이러한 소렌센의 논증이 성립하지 않음을 보이고자 한다. 소렌센의 논증에 대한 가장 일반적인 비판은, 'n-작음'이라는 용어에 기초하는 그의 논증은 '모호함'의 모호함이 아니라 '작음'의 모호함을 입증할 뿐이라는 것이다. 그런데 이러한 비판에 근거한 디즈와 헐의 논의는, 소렌센의 더미를 구성하는 "'n-작음'은 모호하다."의 주어는 언급된 정확한 용어라는 바르찌의 주장에 의해 반박된다. 그러나 필자는 "'n-작음'은 모호하다."의 진리값 결정에 술어 '모호함'이 아무런 역할을 수행하지 못함을 보임으로써 바르찌의 주장을 반박하고, 소렌센의 논증으로부터 정당화되는 것은 '작음'의 모호성뿐임을 보이고자 한다. 물론 필자 역시 '모호함'이 모호하다는 것에는 동의한다. 본 논문을 통해 필자가 주장하는 것은 이러한 '모호함'의 특징에 대한 소렌센의 정당화가 성립하지 않는다는 것뿐이다.

• 논리연구
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• 제20권3호
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• pp.335-366
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• 2017

소렌센(R. Sorensen)은 자신이 제시한 더미 역설(sorites paradox)을 통해 '모호함'이 모호함을 입증하였다. 필자는 이 글에서 소렌센이 제시한 더미 역설이 새로운 역설을 야기함을 보일 것이다. 간단히 말해, 소렌센이 제시한 더미 역설은 더미 역설이 성립하기 위한 조건을 만족하면서 만족하지 못한다는 것이다. 그래서 필자가 제시하는 '소렌센 더미 역설'은 소렌센이 제시한 더미 역설의 역설이라고 할 수 있다. 그런데 더미 역설이 성립하기 위한 조건은 인접한 두 대상 $a_n$, $a{_n}^{\prime}$과 관련된 $P(a_n)$과 $P(a{_n}^{\prime})$의 진리값이 다르지 않다는 것을 포함한다. 그리고 이 조건은 모호성의 정의적 특징을 나타내는 것이기도 하다. 이 조건으로부터 모호한 용어의 적용범위를 구분하는 절단점이 없다는 주장이 도출되기 때문이다. 따라서 필자가 제시하는 소렌센 더미 역설은 모호성 자체가 비일관적임을 보이는 것이라고 할 수 있다.

• 한국전문물리치료학회지
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• 제5권3호
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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.

• 한국해양공학회지
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• 제31권5호
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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.

• PNF and Movement
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• 제15권3호
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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.

• 기계저널
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• 제22권3호
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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.

• Ecology and Resilient Infrastructure
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• 제5권3호
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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.

• Journal of Power Electronics
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• 제5권2호
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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.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2001년도 제41회 종합학술대회 연제초록
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• pp.31-31
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• 2001

• Archives of Pharmacal Research
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• 제17권3호
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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.