• Title/Summary/Keyword: $R_m$

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Phytosociological Studies on the Beech(Fagus multinervis Nakai) Forest and the Pine (Pinus parviflora S. et Z.) Forest of Ulreung Island, Korea (한국 울릉도의 너도밤나무(Fagus multinervis Nakai)림 및 섬잣나무(Pinus parviflora S. et Z.)림의 식물사회학적 연구)

  • 김성덕
    • Journal of Plant Biology
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    • v.29 no.1
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    • pp.53-65
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    • 1986
  • The montane forests of Ulreung Island, Korea, were investigated by the ZM school method. By comparing the montane forests of this island with those of Korean Peninsula and of Japan, a new order, F a g e t a l i a m u l t i n e r v i s, a new alliance, F a l g i o n m u l t i n e r v i s, a new association, H e p a t i c o-F a g e t u m m u l t i n e r v i s and Rhododendron brachycarpum-Pinus parviflora community were recognized. The H e p a t i c o - F a g e t u m m u l t i n e r v i s was further subdivided into four subassociations; Subass. of Sasa kurilensis, Subass. of Rumohra standishii, Subass. of Rhododendron brachycarpum and Subass. of typicum. Each community was described in terms of floristic, structural and environmental features.

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ON WEAKLY QUASI n-ABSORBING SUBMODULES

  • Issoual, Mohammed;Mahdou, Najib;Moutui, Moutu Abdou Salam
    • Bulletin of the Korean Mathematical Society
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    • v.58 no.6
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    • pp.1507-1520
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    • 2021
  • Let R be a commutative ring with 1 ≠ 0, n be a positive integer and M be an R-module. In this paper, we introduce the concept of weakly quasi n-absorbing submodule which is a proper generalization of quasi n-absorbing submodule. We define a proper submodule N of M to be a weakly quasi n-absorbing submodule if whenever a ∈ R and x ∈ M with 0 ≠ an x ∈ N, then an ∈ (N :R M) or an-1 x ∈ N. We study the basic properties of this notion and establish several characterizations.

Type I Thyroplasty Using Prefabricated Hydroxylapatite Implant(VoCoM$^{\circledR}$) (미리 제작된 Hydroxylapatite 보형물을(VoCoM$^{\circledR}$) 이용한 제 1 형 갑상성형술)

  • 이현종;정한신;백정환;손영익
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.14 no.2
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    • pp.117-122
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    • 2003
  • Background and Objectives : $VoCoM^{\circledR}$ is a commercialized set composed of prefabricated hydroxylapatite implants and shims of various sizes which are specially designed for the type I thyroplasty. Even though a previously published preliminary report showed that $VoCoM^{\circledR}$ is a convenient and safe product for the type I thyroplasty, further investigations or experiences are yet to be reported. Authors aimed to evaluate the efficacy of $VoCoM^{\circledR}$type I thyroplasty, and its advantage and/or disadvantage. Materials and Method : Twenty three consecutive patients with unilateral vocal cord palsy enrolled for the study, who received type I thyroplasty with $VoCoM^{\circledR}$ between July 2001 and June 2003. Acoustic, aerodynamic and stoboscopic analyses were performed prior to surgery and 1 to 3 months after surgery. Speech language pathologists evaluated their voice quality by GRBAS scale, and patients themselves reported subjective changes of their voice by visual analog scale. Results : The average time for the operation was 80 min, which is about 30 min less than other methods. Preoperative jitter was 3.25$\pm$1.65% and improved to 1.94$\pm$1.79% postoperatively (p<0.05). Preoperative shimmer was 9.72$\pm$6.56% and improved to 5.61 $\pm$3.76% (p<0.05), Maximal phonation time increased from 4.41$\pm$2.99 to 7.98$\pm$4.35 sec (p<0.05) The postoperative stroboscopy revealed an effective medialization in 91.3% of the patients. The subjective phonetic improvements were reported in 21 out of 23 patients. GRBAS scale improved from 2.71$\pm$0.46 to 1.47$\pm$1.12(p<0.05). Additional medialization with $Gore-Tex^{\circledR}$ was easily performed in two revision cases. Previously inserted $VoCoM^{\circledR}$ implant was hard to remove because of the tight integration of soft tissues around the implant. Side effects such as extrusion or foreign body reaction are not observed. $VoCoM^{\circledR}$ was relatively expensive and costed more than 10 times of $Gore-Tex^{\circledR}$. Conclusion : Prefabricated hydroxylapatitie implant($VoCoM^{\circledR}$) provides a convenient, safe and efficient way of vocal fold medialization. However it is relatively expensive and hard to remove.

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A Possible Test Method Proposed for Resilient Modulus (MR) and Analysis of Correlation between Resilient Modulus and Shear Modulus of Track Subgrade Soil (흙노반재료의 회복탄성계수(MR) 결정을 위한 반복삼축압축시험법 제시 및 변형계수 상관성 분석)

  • Park, Jae Beom;Choi, Chan Yong;Lim, Sang Jin;Lim, Yu Jin
    • Journal of the Korean Society for Railway
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    • v.20 no.1
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    • pp.85-98
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    • 2017
  • In general, under the repetitive dynamic load generated by rail cars running on the track, subgrade soil experiences changes of stress conditions such as deviatoric stress (${\sigma}_d$) and bulk stress (${\theta}$). Due to the repetitive change of deviatoric stress (${\sigma}_d$) with number of loadings, the resilient modulus ($M_R$) can be obtained by using the measured resilient strain (${\varepsilon}_r$) after a sufficient number of loadings. At present, no plausible and unified test method has been proposed to obtain the resilient modulus of railway track subgrade soil. In this study, a possible test method for obtaining the resilient modulus ($M_R$) of railway track subgrade soil is proposed; this test, by utilizing repetitive triaxial compression testing, can consider all the important parameters, such as the confining stress, deviatoric stress, and number of loadings. By adapting and using the proposed test method to obtain $M_R$, $M_R$ values for compacted track subgrade soil can be successfully determined using soil obtained in three field sites of railway track construction with changing water content range from OMC. In addition, shear modulus (G) ~ shear strain (${\gamma}$) relation data were also obtained using a mid-size RC test. A correlation analysis was performed using the obtained G and $M_R$ values while considering the strain levels and modes of strain direction.

Lung/Heart Uptake Ratio in Dipyridamole $^{99m}Tc-MIBI$ Myocardial Perfusion Scan in Coronary Artery Disease (관상동맥질환에서 디피리다몰 부하 $^{99m}Tc-MIBI$ 심근스캔의 폐/심장 섭취율)

  • Kang, Keon-Wook;Lee, Dong-Soo;Choi, Chang-Woon;Lee, Kyung-Han;Chung, June-Key;Lee, Myung-Chul;Seo, Jung-Don;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.27 no.2
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    • pp.218-222
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    • 1993
  • Lung/heart uptake ratio (L/H R) in $^{201}Tl$ myocardial perfusion scan is a reliable marker for long-term prognosis in patients with coronary artery disease. However, the value of L/H R in $^{99m}Tc-MIBI$ myocardial perfusion scan is controversial in determining the prognosis and severity of the coronary artery disease. The purpose of this study was to determine the clinical implications of L/H R in $^{99m}Tc-MIBI$ myocardial perfusion scan. Forty five patients who received $^{99m}Tc-MIBI$ myocardial perfusion scan were divided into control group and coronary artery disease (CAD) group by their clinical findings, EKGs, and $^{99m}Tc-MIBI$ myocardial perfusion scans. Twenty five patients in CAD group were divided into ischemic group and infarct group according to their results from $^{99m}Tc-MIBI$ myocardial perfusion scan. L/H R was calculated on the anterior planar view, 60 minutes after infusion of dipyridamole. Two regions of interest (ROI) were placed on the left lung area 8 pixel above the left ventricle and on the myocardial area which had the highest radioactivity. In the control group, there were no significant differences of L/H R according to sex and age. No significant difference of L/H R was found between the control and CAD group ($0.26{\pm}0.06,\;0.29{\pm}0.05$, p>0.05). In the CAD group, there was also no significant difference of L/H R between the ischemic group and infarct group ($0.29{\pm}0.07,\;0.30{\pm}0.04$, p>0.05). L/H R in CAD group did not show correlations with the defect area of stress polar map (r=0.18, p >0.05) and with the sum of severity weighted extent score or reversibility score which represent severity and extent of myocardial perfusion defect area in stress (r=0.18, p>0.05). We conclude that it is difficult to use L/H R as a marker for severity of CAD in dipyridamole $^{99m}Tc-MIBI$ myocardial perfusion scan.

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$H_{2}$ production of photosynthetic bacteria transferred TOL plasmid from flavobacterium odoratum (Flavobacterium odoratum의 TOL 플라스미드를 전달받은 광합성세균으로부터의 수소 생성)

  • 오순옥;조인성;이희경;민경희
    • Korean Journal of Microbiology
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    • v.29 no.6
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    • pp.408-415
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    • 1991
  • TOL plsmid size of Flavobacterium odoratum SUB53 was estimated as 83 Md and the optimum concentration of m-toluate degradation by TOL plasmid was 5 mM. $H_{2}$ production by Rhodopseudomonas sphaeroides KCTC1425 was largely dependent on nitrogenase activity and showed the highest at 30 mM malate with 7 mM glutamate as nitrogen source. Nitrogenase activities were inhibited by 0.3 mM $NH_{4}^{+}$ions, to be appeared the decrease of $H_{2}$ production. Conjugation of TOL plasmids from F. odoratum SUB53 and Pseudomonas putida mt-2 to R. sphaeroides showed the optimum at the exponential stage of recipient cells in presence of helper plasmid pRK2013. According to the investigation of catechol-1,2-oxygenase (C-1, 2-O) and catechol-2,3-oxygenase (C-2,3-O) activities of R. sphaeroides C1 (TOL SUB53) and C2 (TOL mt-2), the gene for C-2,3-O is located on TOL plasmid and gene for C-1, 2-O on the chromosome of R. sphaeroides. m-Toluate was biodegraded by TOL plasmid in R. sphaeroides C1 and C2, presumably to be produced $H_{2}$ gas from the secondary metabolites of m-toluate.e.

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Influence of Iodinated Magnetic Resonance Contrast Media and Isotope 99mTc on Changes of Computed Tomography Number

  • Kim, Sang-Beom;Lee, Jin-Hyeok;Ahn, Jae-Ouk;Cho, Jae-Hwan
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.302-307
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    • 2015
  • The purpose of the study was to identify how isotope and magnetic resonance imaging (MRI) contrast media impact on noise to computed tomography (CT) examination. For the study, divide the phantoms to two groups: 1) saline, saline + different kinds of contrast agent without $^{99m}Tc$ administration; 2) $^{99m}Tc$ administration: saline, saline + different kinds of contrast agent with $^{99m}Tc$ administration. CT contrast agent was used for Iopamidol$^{(R)}$ and Dotarem. And MRI contrast agent was used for Primovist$^{(R)}$ and Gadovist$^{(R)}$. To obtain an image, we used CT scanner. With an obtained image, we set the $1cm^2$ region of interest in the middle of bottle to measure the noise and CT number. As a result, there was no difference in CT number before and after inserting $^{99m}Tc$ into all contrast media including Normal Saline. However, when it comes to Noise, there was a difference before and after inserting $^{99m}Tc$ into every contrast media except MRI contrast media such as Primovist$^{(R)}$ and Gadovist$^{(R)}$.

Performance of Rotating Biological Contactor (RBC) under Different Hydraulic Loading Rates and Rotational Speeds on Ammonia Removal in a Recirculating System

  • Son Maeng Hyun;Jeon Im Gi;Jo Jae-Yoon;Moon HaeYoung
    • Fisheries and Aquatic Sciences
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    • v.2 no.1
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    • pp.52-57
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    • 1999
  • Air-drived rotating biological contactor (RBC) system, which is effective method in filtering performance, was tested for the nitrification capacity in a recirculating system. At ammonia concentrations between 0.029 and 0.528 mg/l, the effect of ammonia loading rate on ammonia removal rate at three different hydraulic loading rates could be defined by the following first­order regression models: Hydraulic loading rate of $14.8 m^3/m^3/day:\;y=39.2\times+3.4 (r^2=0.9137)$, Hydraulic loading rate of $26.5 m^3/m^3/day: y=53.3\times+4.0 (r^2=0.8686)$, Hydraulic loading rate of $37.3 m^3/m^3/day: y=58.4\times+4.2 (r^2=0.7755)$, where, $\times$ is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3/day)$, The equations showed the optimal ammonia removal rate at the hydraulic loading rate of $26.5m^3/m^3/day$. Below the ammonia concentration of 2.72 mg/l, first-order regression models between ammonia loading rate and ammonia removal rate at three different rates of speed are defined as follows: Rotational speed of $0.75 rpm: y=28.5\times+4.7 (r^2=0.9143)$, Rotational speed of $1.0 rpm: y=33.6\times+8.4 (r^2=0.9534)$, Rotational speed of $2.0 rpm: y=28.9\times+3.6 (r^2=0.9488)$, where, x is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3day)$. The equations show the ammonia removal rate at the rotational speed of 1.0 rpm is significantly higher than that at the rotational speed of either 0.75 rpm or 2.0 rpm (P<0.05).

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주위 지형조건이 소음도 크기에 미치는 영향

  • 이덕수;최희철;강희설;송준익;권두중;유용희;김형호
    • Proceedings of the Korea Society of Poultry Science Conference
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    • 2002.11a
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    • pp.136-137
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    • 2002
  • The study was conducted to examine noise levels influenced by differences of altitudes and elevation from ground level. The results of the study indicated that when the noise (102 db) was created at the upper part of a steep slope area, the noise levels measured at the altitudes of 5 and 10 m were 70 and 62.1 db (R$^2$=0.9533), respectively, and that when the noise (102 db) was created at the lower part of the area, the noise levels levels measured at the altitudes of 5 and 10 m were 74.6 and 71.8 db (R$^2$=0.8519), respectively. When noise was created on a nat area, the noise levels at 10, 20 and 50 meter-ranges were 76.2, 65.9 and 55.3 db (R2 =0.9854), respectively, in which the longer distances from the noise source reduced the noise levels than the shorter and especially the noise was tremendously reduced within 10 meter-range.

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