• 제목, 요약, 키워드: K-group

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Precurved Endosonic K-file에 의한 근관확대율 및 만곡도 변화에 대한 연구 (COMPARATIVE STUDY ON PERCENTAGE OF CANAL ENLARGEMENT AND CANAL ANGULATION CHANGE BY PRECURVED ENDOSONIC K-FILE)

  • 허혜경;오원만;양규호
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.316-327
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    • 1995
  • The purpose of this study was to evaluate canal shaping ability and canal angulation change of K-file, straight endosonic K-file and pre curved endosonic K-file. Twenty staight canals and thirty curved canals were selected and divided into five groups according to canals curvature and canal instrumentation method. VI group was prepared by straight endosonic K-file and H1 group by K-file in straigt canals. V2 group was instrumented by straight endosonic K-file, V3 group by pre curved endosonic K-file and H2 group by precurved K-file in curved canals. Radiographs of canals were obtained before and after canal shaping. And postoperative radiographs were compared with preoperative radiographs using superimposition method. The results obtained were as follows ; l. In straight canals, K-file group demonstrated lager percentage of canal enlargement than endosonic K-file group on facial view, but reverse results exhibit on mesial view. 2. In curved canals, precurved K-file group showed largest percentage of canal enlargement, followed by precurved endosonic K-fine group and straight endosonic K-file group was smallest. 3. Percantage of canal enlargement at convex side was greater than at concave side in apical portion of each group. Especially in straight endosonic K-file group, percantage of canal enlargement at convex side and concave side showed sharply difference. 4. In angulation change, the straight endosonic K-file group exhibited the greatest its change, followed by precurved endosonic K-file group and precurved K-file group was the least. Above results suggest that K-file is more effective endodontic instrument than endosonic K-file, and that precurved file is effective for canal shaping in curved canal.

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ON A GROUP CLOSELY RELATED WITH THE AUTOMORPHIC LANGLANDS GROUP

  • Ikeda, Kazim Ilhan
    • 대한수학회지
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    • v.57 no.1
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    • pp.21-59
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    • 2020
  • Let LK denote the hypothetical automorphic Langlands group of a number field K. In our recent study, we briefly introduced a certain unconditional non-commutative topological group ${\mathfrak{W}}{\mathfrak{A}}{\frac{\varphi}{K}}$, called the Weil-Arthur idèle group of K, which, assuming the existence of LK, comes equipped with a natural topological group homomorphism $NR{\frac{\varphi}{K}^{Langlands}}$ : ${\mathfrak{W}}{\mathfrak{A}}{\frac{\varphi}{K}}$ → LK that we called the "Langlands form" of the global nonabelian norm-residue symbol of K. In this work, we present a detailed construction of ${\mathfrak{W}}{\mathfrak{A}}{\frac{\varphi}{K}}$ and $NR{\frac{\varphi}{K}^{Langlands}}$ : ${\mathfrak{W}}{\mathfrak{A}}{\frac{\varphi}{K}}$ → LK, and discuss their basic properties.

STRONG k-DEFORMATION RETRACT AND ITS APPLICATIONS

  • Han, Sang-Eon
    • 대한수학회지
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    • v.44 no.6
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    • pp.1479-1503
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    • 2007
  • In this paper, we study a strong k-deformation retract derived from a relative k-homotopy and investigate its properties in relation to both a k-homotopic thinning and the k-fundamental group. Moreover, we show that the k-fundamental group of a wedge product of closed k-curves not k-contractible is a free group by the use of some properties of both a strong k-deformation retract and a digital covering. Finally, we write an algorithm for calculating the k-fundamental group of a dosed k-curve by the use of a k-homotopic thinning.

SCALAR EXTENSION OF SCHUR ALGEBRAS

  • Choi, Eun-Mi
    • 대한수학회보
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    • v.42 no.3
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    • pp.453-467
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    • 2005
  • Let K be an algebraic number field. If k is the maximal cyclotomic subextension in K then the Schur K-group S(K) is obtained from the Schur k-group S(k) by scalar extension. In the paper we study projective Schur group PS(K) which is a generalization of Schur group, and prove that a projective Schur K-algebra is obtained by scalar extension of a projective Schur k-algebra where k is the maximal radical extension in K with mild condition.

GROUP ACTIONS ON KAC ALGEBRAS

  • Lee, Jung Rye
    • Korean Journal of Mathematics
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    • v.7 no.1
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    • pp.103-110
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    • 1999
  • For a group action ${\alpha}$ on a Kac algebra $\mathbb{K}$ with the crossed product Kac algebra $\mathbb{K}{\rtimes}_{\alpha}G$, we will show that ${\pi}_{\alpha}(\mathbb{K})$ is a sub-Kac algebra of $\mathbb{K}{\rtimes}_{\alpha}G$. We will also investigate the intrinsic group $G(\mathbb{K})$ of $\mathbb{K}$ and get a group action ${\beta}$ on a symmetric Kac algebra $\mathbb{K}_s(G(\mathbb{K})$ with the crossed product sub-Kac algebra $\mathbb{K}_s(G(\mathbb{K}){\rtimes}_{\beta}G$ of $\mathbb{K}{\rtimes}_{\alpha}G$.

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악관절아탈구증에 대한 두부방사선계측학적 연구 (A Roentgenographic Cephalometric Study of Temporomandibular Joint Subluxation)

  • 김한평
    • 치과방사선
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    • v.11 no.1
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    • pp.23-32
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    • 1981
  • The purpose of this study was to assess temporomandibular joint subluxation by means of cephalometry using two lateral cephalograms from each person with in centric occlusion and wide-open mouth position, and to compare patient group with subluxation to normal control group in the measurements and correlation coefficient. The 200 cephalograms of 100 Korean adults, patient group consisted of 24 females and 26 males ranged from 17 to 63 years age and the normal control group consisted of 20 females and 30 males ranged from 18 to 56 years age, were studied and analyzed statistically. The results were as follows; 1. In the comparison of patient group vs normal control group in the measurements, statistically significant differences were found in C-C', C'-PTM, K-FH, K-PTM, Gn-Gn', C-S-C', Gn-S-Gn', Gn-K-Gn', GoGn-SN, and GoGn-Go'Gn'. K-point* of patient group was located antero - superiorly than of normal control group, and the significance level was higher in K-PTM than in K-FH. There was no statistically significant difference found in local relationship of C-point between patient group and normal control group. The values of correlation coefficient among all measurements were in 0.958≥r≥-0.760, and the highest value was in Gn-Gn' to GoGn-Go'Gn' and Gn-K-Gn' to Gn-Gn', and the lowest value was in C'-PTM to Gn-K-Gn' of normal control group. K was determined as a point of intersection by a perpendicular bisector of Gn-Gn' and a perpendicular bisector of C-C'.

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Vibrio parahaemolyticus에 대한 황금추출물의 항균활성 (Antimicrobial Activities of Scutellariae Radix Extract against Vibrio parahaemolyticus)

  • 조성환;김영록
    • 한국식품영양과학회지
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    • v.31 no.3
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    • pp.534-538
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    • 2002
  • 식품 가물로부터 분리.동정 된 V. parahaemolyticus에 대하여 황금추출물의 항균력을 검토하였다. 바지락 72건 가검물 중에서 66건(91.7%)이 양성으로서 높은 검출율을 보였다. 슬라이드 응집법으로 혈청형을 확인한 결과 분리 된 V. parahaemolyticus 66균주 중에서 혈청형을 결정할 수 없는 UT(untypeable) K-group이 46균주로서 69.7%였으며, 확인된 혈청형 중에서는 serotype K-I group이 7균주로서 10.6%의 검출율을 나타내었고, K-IV group 5균주(7.6%), K-II, V, VII group이 각각 2균주(3.0%)이 었으며, K-VI, VIII group 1균주(1.5%)의 순으로 분리되었고, K-III와 IX group 혈청형은 검출되지 않았다. 식품에 있어서 생육관계를 조사하기 위하여 시판되는 바지락을 시료로 분리균주들을 각각 접종한 다음35$^{\circ}C$에서 120시간동안 배양하여 얻은 생육곡선에서 V. parahemolyticus균주들 모두가 유도기, 대수기, 정지기, 사멸기를 거치는 전형적인 S자 모양의 생육곡선을 보였다. 식품에 대한 황금추출물의 항균작용을 알아보기 위하여 시판되는 바지락을 시료로 하여 증기 멸균한 후, 동량의 멸균생리식염수를 넣고 황금추출물의 농도가 0, 500, 1000, 5000 ppm (mg/kg)이 되도록 균질화시킨 시료에 분리균주들을 각각 접종한 다음, 35$^{\circ}C$에서 48시간 동안 배양하여 얻은 생육저해곡선에서 V. parahaemolyticus 균주들 모두가 유도기를 거친 다음인 6시간이 경과된 후 황금추출물의 농도에 따라 시험균주의 균수 차이를 보였고, 식품중의 Vibrio parahaemolyticus에 있어서 생육이 억제되는 황금추출물 유효저해농도는 1000ppm이었다. 세포형태변화를 관찰하기 위한 투과형전자현미경(TEM) 상에서 황금추출물 처리로 인한 V. parahaemolyticus균주들의 세포막기능의 파괴로 세포내용물들이 용출된 것을 볼 수 있었다.

갑상샘 초음파 검사에서 K-TIRADS 점수화 체계를 사용한 양성과 악성 갑상샘 결절의 감별진단 (Differential Diagnosis of Benign and Malignant Thyroid Nodules Using the K-TIRADS Scoring System in Thyroid Ultrasound)

  • 안현;임인철;이효영
    • 한국방사선학회논문지
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    • v.13 no.2
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    • pp.201-207
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    • 2019
  • 본 연구는 갑상샘 초음파에서 K-TIRADS 분류와 K-TIRADS 분류에 따른 Different risk group의 조합을 이용한 방법이 양성과 악성 결절의 감별진단에 유용한지를 평가하였다. 갑상샘 초음파를 시행한 210명을 대상으로 하였으며, 세침흡인세포검사 결과를 바탕으로 후향적인 분석을 하였다. 갑상샘 결절의 양성과 악성에 따른 K-TIRADS와 Different risk group의 점수체계의 차이 분석은 카이제곱 검정을 하였다. ROC 곡선 분석을 통해 악성 결절의 예측을 위한 K-TIRADS 점수와 Different risk group의 최적 cut off 값을 결정하였다. 양성과 악성 결절 군의 분류에 따른 K-TIRADS와 Different risk group의 차이검증 결과에서 각각 통계적으로 유의한 차이를 보였다(p=.001). ROC 곡선 분석에서 양성과 악성 결절의 예측을 위한 K-TIRADS에 따른 점수분류에서는 AUC 0.786, Cut-off value> 2를 나타내었으며, Different risk group에서는 AUC 0.640, Cut-off value> 2로 결정되었다(p=.001). 갑상샘 초음파에서 결절을 발견했을 때 양성과 악성 갑상샘 결절을 감별하는 데 도움을 주는 K-TIRADS에 따른 분류체계가 Different risk group에 따른 분류체계보다 갑상샘 결절의 감별진단에 도움을 줄 것으로 생각하며 K-TIRADS에 따른 분류체계를 적용하면, 불필요한 세포 검사를 줄일 수 있고, 악성 결절의 조기발견에 도움이 될 것으로 생각된다.

종양세포(腫瘍細胞)의 염색체(染色體)에 대한 오크라톡신 A의 독성(毒性)에 관한 연구(硏究) (Studies on toxicity of ochratoxin A to chromosomes of turmor cell-line)

  • 윤화중;노민희;김강련
    • 대한수의학회지
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    • v.29 no.2
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    • pp.51-57
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    • 1989
  • This study was performed to investigate the toxicity of ochratoxin A (OA) to the chromosomes of $K_{562}$ tumor cell-line in vitro. The results of this experiment were as follows: 1) Chromosomes of $K_{562}$tumor cell-line resulted in pseudotriploidy on the control group. Chromosomes of $K_{562}$ tumor cell-line treated with OA resulted in heteroploidy compared with the control group. The mean number of chromosomes in the karyotype of the control group (60) were 7 in the A group, 5 in the B group, 20 in the C+X group, 7 in the D group, 9 in the E group, 6 in the F group, and 6 in the G+Y group respectively. The number of chromosomes were increased as follows: Treating with $0.7{\mu}M$ OA, the number of chromosomes were increased one in E and F group, two in G+Y group compared with control group. In treated with $1.5{\mu}M$ OA, the increasing number of chromosome was one in E and F group. In treated with $3{\mu}M$ OA, E and F group was increased one and G+Y group were increased two chromosomes compared with control group. But in treated with $6{\mu}M$ OA, the number of chromosome in G+Y group was decreased one. 2) $K_{562}$ tumor cell line treated with OA showed Philadelphia-Chromosome in the long arm of the G group karyotype chromosome. The rate of chromosome aberration in $K_{562}$ tumor cell-line treated with OA was 77% in $0.7{\mu}M$ OA group, 71% in $1.5{\mu}M$ OA group, 82% in $3{\mu}M$ OA group and 94% in $6{\mu}M$ OA group respectively. The rate of chromosome aberration of $K_{562}$ tumor cell-line treated with OA was high in the high dose level of OA, and chromosome aberration of $K_{562}$ tumor cell-line treated with OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype. As a result of this study, the toxicity of OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype, and then, the toxicity of OA resulted in the damage to RNA and protein synthesis in $K_{562}$ tumor cell-line, and the C-group karyotype of $K_{562}$ tumor cell-line was target of the toxicity of OA.

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