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1.
Dr. Richard Koch 《Monatshefte für Mathematik》1977,83(2):133-146
Let ={e(u)|uI} be a one-parameter family of straight lines forming a ruledC
r-2-surface E
n (n2,r1) without singular generatorse(u) (uI). As a synopsis, a generalization and an improvement of various results already known about the strictional properties of ruled surfaces E
n (especially in the casen=3) the author demonstrates a uniform geometrical way of defining and uniquely obtaining thestriction point S(u) and theparameter of distribution d(u) of a generatore(u) under the minimal assumptions thate(u)E
n
(n2) be noncylindrical andr1. Other methods of obtainingS(u) andd(u) are discussed in comparison, and special strictional properties ofskew ruled surfaces E
n are proved.
Herrn Prof. Dr. H. R. Müller zum 65. Geburtstag 相似文献
Herrn Prof. Dr. H. R. Müller zum 65. Geburtstag 相似文献
2.
Let be a fixed point free group given by the presentation
where and are relative prime numbers, t = /s and s = gcd( – 1,), and is the order of modulo . We prove that if (1) = 2, and (2) is embeddable into the multiplicative group of some skew field, then is circular. This means that there is some additive group N on which acts fixed point freely, and |((a)+b)((c)+d)| 2 whenever a,b,c,d N, a0c, are such that (a)+b(c)+d. 相似文献
3.
C. W. Onneweer 《Analysis Mathematica》1978,4(4):297-302
G- p- . [5] - (G) L
r(G) (1r<), . . , - . , , , . . , X. , . (. [1], [2] [4]). 相似文献
4.
Frank O. Wagner 《Archive for Mathematical Logic》1994,33(1):23-34
The following theorems are proved about the Frattini-free componentG
of a soluble stable -group: a) If it has a normal subgroupN with nilpotent quotientG
/N, then there is a nilpotent subgroupH ofG
withG
=NH. b) It has Carter subgroups; if the group is small, they are all conjugate. c) Nilpotency modulo a suitable Frattini-subgroup (to be defined) implies nilpotency. The last result makes use of a new structure theorem for the centre of the derivative of the Frattini-free component of a centreless soluble -group. 相似文献
5.
, . , L
p
(2) p>1 . , C(T3), - , . - .
This work was completed while the first named author was a visiting professor at Indiana University, Bloomington, Indiana; and the second named author was a visiting professor at Ohio State University, Columbus, Ohio, U.S.A. 相似文献
This work was completed while the first named author was a visiting professor at Indiana University, Bloomington, Indiana; and the second named author was a visiting professor at Ohio State University, Columbus, Ohio, U.S.A. 相似文献
6.
7.
Otto Röschel 《Journal of Geometry》1992,44(1-2):160-170
We study a map of osculating elements of an affine Cayley- Klein (CK-) plane into the Lie algebraA
4(2) of the aequiform transformationsA
4(2) of the given plane. If we use the real projective spaceP
3() overA
4(2) each osculating element defines a straight line inP
3(). In the first part of this paper this map is studied in detail. In the second part we study second order properties of one- parameter motions and their corresponding properties in the Lie algebraA
4(2). This is done by considering the analogen to the formula of EULERSAVARY in the image spaceP
3() overA
4(2). 相似文献
8.
S. P. Zhou 《Analysis Mathematica》1994,20(2):155-159
[Zho2] {x
n
} ,
n
0 n .
Supported in part by an NSERC Postdoctoral Fellowship and a CRF grant of University of Alberta. 相似文献
Supported in part by an NSERC Postdoctoral Fellowship and a CRF grant of University of Alberta. 相似文献
9.
On log-hyponormal operators 总被引:9,自引:0,他引:9
Kôtarô Tanahashi 《Integral Equations and Operator Theory》1999,34(3):364-372
LetTB(H) be a bounded linear operator on a complex Hilbert spaceH.TB(H) is called a log-hyponormal operator itT is invertible and log (TT
*)log (T
*
T). Since log: (0, )(–,) is operator monotone, for 0<p1, every invertiblep-hyponormal operatorT, i.e., (TT
*)
p
(T
*
T)
p
, is log-hyponormal. LetT be a log-hyponormal operator with a polar decompositionT=U|T|. In this paper, we show that the Aluthge transform
is
. Moreover, ifmeas ((T))=0, thenT is normal. Also, we make a log-hyponormal operator which is notp-hyponormal for any 0<p.This research was supported by Grant-in-Aid Research No. 10640185 相似文献
10.
R
n. , , , F R
n, F , R
n R
n .
p,q
(Rn), >0, 1, q, — ( ) Rn. ,
p,q
(Rn) F Rn. , q B
p,q
(F), = – (n–)/, >0, — « », ad — F, . , . : , F=R
d,F— « » F— R
n, « », F. .
This work has been supported in part by the Swedish Natural Science Research Council. 相似文献
This work has been supported in part by the Swedish Natural Science Research Council. 相似文献
11.
{p
mn
} -
00>0, (1, 1) (1.1) (1.2). {s
mn
} J
p
- ( bJ
p
-lims
mn
=), (1.3) 0<x,y<1 p
s
(, )/p(x, y) x, y 1-. {r
mn
} - , (1.5) 0<, <1. N
rp
- , (1.6). , bJ
p
-lims
mn
= bJ
q
-lim(N
rps)
mn
=. J
p
- . , . 相似文献
12.
Yu. F. Korobeinik 《Analysis Mathematica》1986,12(3):167-173
X
2
={x
k
}
k=2
X={x
k
}
k=1
. , , ( , ) . , , X— , , X
2 H, , , , , X
2 H. 相似文献
13.
S. R. Treil' 《Journal of Mathematical Sciences》1989,44(6):868-869
It is proved that for every sequence of points n from the unit circle, n1, and for an arbitrary sequence of positive numbers An, An, there exists a continuous real function u, such that for the Toeplitz operator T (acting in the Hardy space H2) with the symbol =e
iu
we have the estimates (T–nI)–1>An, n.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova, AN SSSR, Vol. 157, pp. 175–177, 1987. 相似文献
14.
N. B. Lebedinskaya 《Journal of Mathematical Sciences》1983,22(2):1203-1207
For a class of structural sets of penalty functions={i}
i=1
n
with lower quasiconvex functions
i defined for sets of jobs={i}
i=1
n
, one gives an algorithm for solving the problem n /1/ preemp ¦ max, having order 0(np), where n is the number of jobs i and p is the total length of the completion of all jobs of the set.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 102, pp. 61–67, 1980.In conclusion, the author expresses her gratitude to K. V. Shakhbazyan for his interest in this paper. 相似文献
15.
Segmentation under geometrical conditions using geodesic active contours and interpolation using level set methods 总被引:3,自引:0,他引:3
Let I: be a given bounded image function, where is an open and bounded domain which belongs to n. Let us consider n=2 for the purpose of illustration. Also, let S={xi}i be a finite set of given points. We would like to find a contour , such that is an object boundary interpolating the points from S. We combine the ideas of the geodesic active contour (cf. Caselles et al. [7,8]) and of interpolation of points (cf. Zhao et al. [40]) in a level set approach developed by Osher and Sethian [33]. We present modelling of the proposed method, both theoretical results (viscosity solution) and numerical results are given.
AMS subject classification 49L25, 74G65, 68U10 相似文献
16.
17.
, (n), - (P
n
), P
n
(A
n
)>0P
n
(A
n
)0,n. [15] - , . , P
n
P
n
T
n
T
n
. 相似文献
18.
Guohui Tian 《K-Theory》2000,19(2):185-193
Let A be a complex Banach algebra. In this paper, we prove a periodicity theorem that K(S
2
A, G, )K(A, G,), where (A,G,) is a finite covariant system and K(A,G,) is an Abelian group associated with (A,G,). 相似文献
19.
V. F. Gapoškin 《Analysis Mathematica》1980,6(2):105-119
a
k
f
k
, f
k
L
2, w-, (2), w(n) — .
a
k
f
k
N {a
k
}l
2, {a
k
}l
2 ( 1, 2, 1a, 2a). ( 2) [8]. , {a
k
} w-. 相似文献
20.
A model in which strongness of is indestructible under + -weakly closed forcing notions satisfying the Prikry condition is constructed. This is applied to solve a question of Hajnal on the number of elements of {
|2
<}. 相似文献