• Title, Summary, Keyword: K-group

Search Result 5,633, Processing Time 0.052 seconds

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

  • Hur, Heuy-Keung;Oh, Won-Mann;Yang, Kyu-Ho
    • Restorative Dentistry and Endodontics
    • /
    • v.20 no.1
    • /
    • pp.316-327
    • /
    • 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.

  • PDF

ON A GROUP CLOSELY RELATED WITH THE AUTOMORPHIC LANGLANDS GROUP

  • Ikeda, Kazim Ilhan
    • Journal of the Korean Mathematical Society
    • /
    • v.57 no.1
    • /
    • pp.21-59
    • /
    • 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
    • Journal of the Korean Mathematical Society
    • /
    • v.44 no.6
    • /
    • pp.1479-1503
    • /
    • 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
    • Bulletin of the Korean Mathematical Society
    • /
    • v.42 no.3
    • /
    • pp.453-467
    • /
    • 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
    • /
    • v.7 no.1
    • /
    • pp.103-110
    • /
    • 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 $\mathbb{K}{\rtimes}_{\alpha}G$.

  • PDF

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

  • Kim Han Pyong
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.11 no.1
    • /
    • pp.23-32
    • /
    • 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'.

  • PDF

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

  • 조성환;김영록
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.31 no.3
    • /
    • pp.534-538
    • /
    • 2002
  • To investigate the antimicrobial effects of Scutellariae Radix extract against Vibrio parahaemolyticus from food samples, Vibrio parahaemolyticus strains isolated from Tapes philippinarum were examined for their sensitivity to Scutellariae Radix extract. Total 66 Vibrio parahaemolyticus strains were isolated from Tapes philippinarm 72 samples (91.7%). The serotypes of isolated Vibrio parahemolytics were K-I group 7 strains (10.6%), K-IV group 5 strains (7.6%), K-II group 2 strains (3.0%), K-V group 2 strains (3.0%), K-VII group 2 strains (3.0%), K-VI group 1 strains (1.5%), K-VIII group 1 strains (1.5%) and antisera UT K-group 46 strains (69.7%) on antisera agglutination test, but K-III group and K-IX group strains were not found. The growth curves of isolates showed lag phase, logarithmic phase, stationary phase and death phase as typical sigmoid curve on the shellfish samples. After 6 hours, the group containing Scutellariae Radix extract differs from the control on shellfish samples in the growth inhibition curves, and Vibrio parahaemolyticus were inhibited in more than 1000 ppm Scutellariae Radix extract. The morphological changes were observed by transmission electron microscope and the microbial cells membrane was destroyed by Scutellariae Radix extract.

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

  • An, Hyun;Im, In Cheol;Lee, Hyo-Yeong
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.2
    • /
    • pp.201-207
    • /
    • 2019
  • This study has evaluated whether the method of using the combination of different risk group, according to K-TIRADS classification and K-TIRADS classification in thyroid ultrasonography is useful in a differential diagnosis of benign and malignant nodules. The subject was patients underwent thyroid ultrasonography and retrospective analysis were performed based on the results of fine needle aspiration cytology. A chi-square test was performed for the difference analysis of the score system in K-TIRADS and different risk group according to the benign and malignant of thyroid nodule. The optimized cut off value was determined by the K-TIRADS score and different risk group to predict malignant nodule through ROC curve analysis. In the differential verification result of K-TIRADS and different risk group, according to the classification of benign and malignant nodule group each showed significant difference statistically(p=.001). In the point classification according to K-TIRADS for the prediction of benign and malignant in ROC curve analysis showed AUC 0.786, Cut-off value>2(p=.001), and in the different risk group, it was decided as AUC 0.640, Cut-off value>2(p=.001). When discovering the nodule in thyroid ultrasound, it is considered that the K-TIRADAS which helps in identifying benign and malignant thyroid nodules, it is considered to be helpful in the differential diagnosis of thyroid nodules, than the classification system according to Different risk group, and when applying the classification system according to K-TIRADS, it is considered that it can reduce unnecessary fine needle aspiration cytology and could be helpful in finding the malignant nodules early.

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

  • Yoon, Wha-jung;Roh, Min-hee;Kim, Kang-ryun
    • Korean Journal of Veterinary Research
    • /
    • v.29 no.2
    • /
    • pp.51-57
    • /
    • 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.

  • PDF