• 제목/요약/키워드: W.T.

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TWO GENERALIZATIONS OF LCM-STABLE EXTENSIONS

  • Chang, Gyu Whan;Kim, Hwankoo;Lim, Jung Wook
    • 대한수학회지
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    • 제50권2호
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    • pp.393-410
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    • 2013
  • Let $R{\subseteq}T$ be an extension of integral domains, X be an indeterminate over T, and R[X] and T[X] be polynomial rings. Then $R{\subseteq}T$ is said to be LCM-stable if $(aR{\cap}bR)T=aT{\cap}bT$ for all $0{\neq}a,b{\in}R$. Let $w_A$ be the so-called $w$-operation on an integral domain A. In this paper, we introduce the notions of $w(e)$- and $w$-LCM-stable extensions: (i) $R{\subseteq}T$ is $w(e)$-LCM-stable if $((aR{\cap}bR)T)_{w_T}=aT{\cap}bT$ for all $0{\neq}a,b{\in}R$ and (ii) $R{\subseteq}T$ is $w$-LCM-stable if $((aR{\cap}bR)T)_{w_R}=(aT{\cap}bT)_{w_R}$ for all $0{\neq}a,b{\in}R$. We prove that LCM-stable extensions are both $w(e)$-LCM-stable and $w$-LCM-stable. We also generalize some results on LCM-stable extensions. Among other things, we show that if R is a Krull domain (resp., $P{\upsilon}MD$), then $R{\subseteq}T$ is $w(e)$-LCM-stable (resp., $w$-LCM-stable) if and only if $R[X]{\subseteq}T[X]$ is $w(e)$-LCM-stable (resp., $w$-LCM-stable).

750 kW 풍력발전기의 소음 실증 (Noise Test and Evaluation of a 750 kW Wind Turbine Generator)

  • 김석현;김태형
    • 한국소음진동공학회논문집
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    • 제16권2호
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    • pp.124-131
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    • 2006
  • This study introduces an environmental noise evaluation procedure for wind turbines(W/T) and the evaluation result of a 750 kW wind turbine(W/T) system. Test and evaluation are performed according to the international standard IEC 61400-11 on J48 W/T which is under operation in Daekwanryung W/T test site. With the meteorological data and W/T operational data, noise data are monitored and analysed. An integrated monitoring system is constructed in the test site and is utilized for the evaluation. From the measured noise data, acoustic power level, directivity and tonality of the W/T are estimated under the wind speeds required fly the International standard. The purpose of the study is to establish an W/T noise evaluating system satisfying the international standard and to obtain noise data for home made 750 kW W/T.

토양수분의 과, 부족이 연초의 생장과 증발산량에 미치는 영향 (EFFECT OF SOIL mOISTURE CONDITiON ON THE GROWTH AND EVAPOTRANSPIRATION OF THE TOBACCO PLANT)

  • 홍순달;이윤환;김재정;조성진
    • 한국연초학회지
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    • 제7권1호
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    • pp.15-23
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    • 1985
  • Growth response and evapotranspiration of tobacco as to each soil moisture condition treated with different height of ground water table such as 30cm, 100cm, 170cm, and 230cm were investigated. The results obtained were as follows; 1. Soil water potential in the rhizosphere (25cm depth from surface) treated with ground water table (G.W.T) of 230 cm was less than -6.5 bar at 60 days after transplanting. 2. Dry weight of leaves per plant was the highest in the pot treated with 100 cm G.W.T and was the lowest in the pot treated with 230 cm G.W.T.. Leaves/Stem ratio of dry weight was the lowest in the pot treated with 230 cm G.W.T. This would show that extension of leaves as compared with elongation of stem was suppressed. .3. In the roster stress condition of 230 cm G.W.T., extension of leaves was continued until the latter growth stage, Relative growth rate of leaf area per plant of the pot with 30 cm G.W.T. was the highest through all growth period after fixation of G.W.7., but owing to lower density of leaf, the dry weight of leaves per plant was less rather than that of the pot with 170 cm G.W.T. at 64 days after transplanting. 4. The highest evapotranspiration per plant per day was shown at the 45th day after transplanting in the pots with 30cm and 100cm G.W.T. and at 60 days in the pots with 170cm and 230cm G.W.T respectively. 5. In the soil moisture conditions with 30cm and 100cm G.W.T., evapotranspiration per plant per hour was much higher in the daytime that at night as well as in clear day than in rain-cloudy day owing to loner relative humidity , but in the water stress condition with 230 cm G.W.T., that was much lower. 6. Total evapotranspiration per plant during the whole growing period of 64 days was in order of 30cm > 100 cm > 170 cm > 230 cm G.W.T.. Total evapotranspiration for 34 days after fixation of G.W.T was much higher at night than in the daytime in case of water stress conditions i.e 170cm and 230cm G.W.T. but in normal condition of the pots with 30cm and 100cm G.W.T. that was much higher in the daytime than at night. 7. Leaf water potential of the 3rd and 6th leaf from top at 64 days after transplanting was in order of 100cm > 30 cm > 170cm > 230cm G.W.T. The reason why leaf water potential in the pot with 30cm was less than that in the pot with 100cm G.W.T. would be the abnormal turgidity with low density of cell substrates by the excess water absorption in the pot with 30cm G.W.T..

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중층트롤의 깊이바꿈과 소해심도의 안정성 (Depth Control and Sweeping Depth Stability of the Midwater Trawl)

  • 장지원
    • 수산해양기술연구
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    • 제9권1호
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    • pp.1-18
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    • 1973
  • 중층트를 어구(漁具)의 소해심도(掃海深度)를 일정(一定)한 적정어획속도(適正漁獲速度)에서 기동성(機動性)있게 변화(變化)시키기 위하여 기초적인 모형어구(模型漁具)의 수조실험(水槽實驗)과 특별(特別)히 고안한 깊이바꿈틀을 이용(利用)한 이차(二次)에 걸친 해상시험(海上試驗)을 통(通)하여 연구한 결과를 요약(要約)하면 다음과 같다. 1. 중층(中層)트롤의 그물어구의 깊이 y는 끌줄의 길이 L과 단위(單位) 길이의 끌줄, 깊이바꿈틀 및 그물의 각(各) 수중중량(水中重量) $W_r,\;W_o,\;W_n$과 각(各) 항력(抗力) $R_r,\;R_o,\;R_n$ 사이의 관계(關係)는 차원해석법(次元解析法)에 의하면 다음과 같다. $$y=kLf(\frac{W_r}{R_r},\;\frac{W_o}{R_o},\;\frac{W_n}{R_n})$$ 단(但), k는 상수(常數)이고 f는 함수이다. 2. 단위 길이당(當)의 수중중량(水中重量) $W_r$, 길이 L인 끌줄 끝에 항력(抗力) $D_n$, 수중중량(水中重量) $W_n$d인 수중저항분를 매달고 끌줄의 다른 한 끝을 수면(水面)에서 예인(曳引)할 때,. 끌줄의 형상(形狀)을 현수곡선이라고 보면, 수중저항분의 깊이 y는 다음과 같다. $$y=\frac{1}{W_r}\{\sqrt{{D_n^2}+{(W_n+W_rL)^2}}-\sqrt{{D_n^2+W_n}^2\}$$ 3. 중층(中層)트롤의 그물어구(漁具)깊이의 변화(變化) ${\Delta}y$는 예강(曳綱)의 길이 L을 바꾸거나 추(錘) ${\Delta}W_n$를 부가(附加)하면 다음과 같다. $${\Delta}y{\approx}\frac{W_n+W_{r}L}{\sqrt{D_n^2+(W_n+W_{r}L)^2}}{\Delta}L$$ $${\Delta}y{\approx}\frac{1}{W_r}\{\frac{W_n+W_rL}{\sqrt{D_n^2+(W_n+W_{r}L)^2}}-{\frac{W_n}{\sqrt{D_n^2+W_n^2}}\}{\Delta}W_n$$ 단(但), $D_n$은 그물어구의 항력(抗力)이다. 4. 끌줄 상(上)의 중간점(中間点)에 추(錘) $W_s$를 부가(附加)할 때 중층(中層)트롤 그물어구의 깊이바꿈 ${\Delta}y$$${\Delta}y=\frac{1}{W_r}\{(T_{ur}'-T_{ur})-T_u'-T_u)\}$$ 단(但) $$T_{ur}^l=\sqrt{T_u^2+(W_s+W_{r}L)^2+2T_u(W_s+W_{r}L)sin{\theta}_u$$ $$T_{ur}=\sqrt{T_u^2+(W_{r}L)^2+2T_uW_{r}L\;sin{\theta}_u$$ $$T_{u}'=\sqrt{T_u^2+W_s^2+2T_uW_{s}\;sin{\theta}_u$$ $T_u$ 추(錘)를 부가(附加)하지 않았을 때 끌줄 상(上)의 중간점(中間点)에 있어서의 예인어선(曳引漁船) 쪽을 향하는 장력(張力)이고, ${\theta}_u$는 장력(張力) $T_u$와 수평방향(水平方向)과 이루는 각도(角度)이다. 5. 어떠한 형태(形態)의 저예강용(底曳綱用) 전개판(展開板)도 성능(性能)에 있서어 차이는 있으나 전중량(全重量)을 가볍게 하고 저변(底邊)에 무게를 달아 안정(安定)시키면 중층예강용(中層曳綱用)으로 사용(使用)할 수 있다는 것이 모형(模型) 실험(實驗)결과 밝혀졌다. 6. 모형(模型) 그물(Fig.6)의 수조실험(水槽實驗)에서는 예강속도(曳綱速度) v m/sec, 강고(綱高) H cm 및 수유저항(水流抵抗) R kg 사이에는 다음과 같은 간단(簡單)한 관계식(關係式)이 성립(成立)한다. $$H=8+\frac{10}{0.4+v}$$$R=3+9v^2$$ 7. 특별(特別)히 고안한 십자(十字)날개형(型) 깊이바꿈틀과 H날개형(型) 깊이 바꿈틀을 비교(比較)한 결과(結果) 전자(前者)보다 안정성(安定性)이 우월하였다. 8. 그물어구(漁具)의 유수저항(流水抵抗)이 매우 크며 또 거의가 항력(抗力)으로 볼 수 있으므로 깊이바꿈틀의 종류에 관계없이 그물어구의 소해심도(掃海深度)는 대단히 안정(安定)된 상태를 유지하였다. 9. H날개형(型) 깊이바꿈틀의 수평(水平)날개 면적율 $1.2{\times}2.4m^2$로 하였을 때 유수저항(流水抵抗) 2 ton의 그물 어구를 2.3kts로 예인(曳引)하면서 영각(迎角)을 $0^{\circ}{\sim}30^{\circ}$로 변화(變化)시킨 결과(結果), 끌줄의 길이에 관계없이 약(約) 20m의 깊이바꿈을 얻을 수 있었다.

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1kW소형 풍력발전기의 진동 모니터링 (Vibration Monitoring of a 1kW Small Wind Turbine Generator)

  • 김석현;남윤수;유능수;김윤호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.308-311
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    • 2006
  • A vibration monitoring is performed on a 1kW class stand alone wind turbine(W/T). When a W/T model is developed, general performance under various wind condition should be verified to introduce the product in the market. Especially, vibration characteristics within operating speed range are very important in the aspect of structural stability as well as generator's electrical efficiency. This paper examines the vibration performance of a home made 1kW W/T Various data of the W/T model are acquired in real time using a remote vibration monitoring system installed in Daekwanryung test site. Vibration stability of the W/T structure is diagnosed based upon the data and the result is used to estimate the applicability of the W/T model.

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Time Dependent Fourier Transform, Time Dependent Spectrum Density 및 그의 응용

  • 안수길
    • 대한전자공학회논문지
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    • 제13권4호
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    • pp.1-5
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    • 1976
  • Spectrum의 시간기복을 나타내는 시간 및 주파수의 함수 F(w,t,T) 및 W(w,t,T)를 정의하였고, 실례에 적용시켰다. Fourier변환을 f(t)와 Phasor ejwt와의 Correlation으로 정의하였고 그 변환시분이 시간마다의 성분의 합계이어서 t 시각에서의 Spectrum을 그 근거에서의 f(t)값에만 의함을 증명하였다. Two new time functions defining Time Dependent Fourier Transform F(w,t,T) and Time Dependent Spectrum Density W(w,t,T) are deduced. courier transform is defined as the correlation between the time function f(t) and phasor ejwt. Several theorems corncerning the new functions are proved in order to verify the instantaneous cause a effet of the function f(t) and the nuctuating spectrum.

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A NOTE ON w-GD DOMAINS

  • Zhou, Dechuan
    • 대한수학회보
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    • 제57권6호
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    • pp.1351-1365
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    • 2020
  • Let S and T be w-linked extension domains of a domain R with S ⊆ T. In this paper, we define what satisfying the wR-GD property for S ⊆ T means and what being wR- or w-GD domains for T means. Then some sufficient conditions are given for the wR-GD property and wR-GD domains. For example, if T is wR-integral over S and S is integrally closed, then the wR-GD property holds. It is also given that S is a wR-GD domain if and only if S ⊆ T satisfies the wR-GD property for each wR-linked valuation overring T of S, if and only if S ⊆ (S[u])w satisfies the wR-GD property for each element u in the quotient field of S, if and only if S𝔪 is a GD domain for each maximal wR-ideal 𝔪 of S. Then we focus on discussing the relationship among GD domains, w-GD domains, wR-GD domains, Prüfer domains, PνMDs and PwRMDs, and also provide some relevant counterexamples. As an application, we give a new characterization of PwRMDs. We show that S is a PwRMD if and only if S is a wR-GD domain and every wR-linked overring of S that satisfies the wR-GD property is wR-flat over S. Furthermore, examples are provided to show these two conditions are necessary for PwRMDs.

Paenibacillus gyeongsangnamensis sp. nov., Isolated from Soil

  • Hyosun Lee;Dhiraj Kumar Chaudhary;Dong-Uk Kim
    • Journal of Microbiology and Biotechnology
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    • 제34권8호
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    • pp.1636-1641
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    • 2024
  • A Gram-stain-positive, aerobic, white-coloured, rod-shaped bacteria, designated as a strain dW9T, was isolated from soil. Strain dW9T was catalase-positive and oxidase-negative. Strain dW9T grew at temperature of 20-37℃ and at pH of 5.0-7.0. Phylogenetic and 16S rRNA gene analysis indicated that strain dW9T belonged to the genus Paenibacillus with its closest relative being Paenibacillus filicis S4T (97.4% sequence similarity). The genome size of dW9T was 7,787,916 bp with DNA G+C G+C content of 51.3%. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of dW9T with its closest relatives were found to be <22.0% and <74.0%, respectively. The only respiratory quinone was MK-7, and the major fatty acids were antiso-C15:0 and iso-C16:0. Overall, the comprehensive taxonomic analysis revealed that strain dW9T met all the fundamental criteria to be classified as a novel species within the genus Paenibacillus. Accordingly, we propose the name Paenibacillus gyeongsangnamensis sp. nov., with the type strain dW9T (=KCTC 43431T =NBRC 116022T).

COMPLEX DELAY-DIFFERENTIAL EQUATIONS OF MALMQUIST TYPE

  • NAGASWARA, P.;RAJESHWARI, S.
    • Journal of applied mathematics & informatics
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    • 제40권3_4호
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    • pp.507-513
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    • 2022
  • In this paper, we investigate some results on complex delay-differential equations of the classical Malmquist theorem. A classic illustrations of their results states us that if a complex delay equation w(t + 1) + w(t - 1) = R(t, w) with R(t, w) rational in both arguments admits (concede) a transcendental meromorphic solution of finite order, then degwR(t, w) ≤ 2. Development and upgrade of such results are presented in this paper. In addition, Borel exceptional zeros and poles seem to appear in special situations.

Magnetic resonance images of ameloblastoma

  • Kim Jae-Duk;Kim Jin-Soo
    • Imaging Science in Dentistry
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    • 제35권4호
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    • pp.207-213
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    • 2005
  • Purpose: To classify and describe the characteristic features of MRI of some ameloblastoma variants. Materials and Methods: The MR images, CT images, and panoramic radiographs in 5 cases were retrospectively examined as follows. First, the contents of ameloblastomas were devided into two portions of either solid or cystic components on the basis of MR signal intensities. The signal intensity within the solid or cystic portions was classified as homogeneous or heterogeneous. Next, the characteristic internal feature of the lesion on T1W1 or T2WI was described. The signal intensities were classified into low, intermediate, slightly high, high, and strong high signal intensity. Results: Unicystic lesion showed homogeneous high signal intensity (SI) on T2W2 and the rim enhancement of the surrounding area including the mural nodule and the thick wall except the central portion on Gd- T1W1. Solid type revealed heterogeneous and high SI area with strong high SI area on T2W2. On Gd- T1W1, the area corresponding to the low signal spot on T1W1 and the strong high signal spot on T2W1 showed low SI. Hybrid type showed slightly enhanced capsular structures and low SI for the round bony septa and the areas connecting the mixed and cystic lesions on T2Wl and Gd-T1W1. Conclusion: MRI could easily assess the relationship between the mixed and cystic findings in ameloblastoma.

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