Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
HYPERRULED SURFACES IN MINKOWSKI 4-SPACE
341
347
EN
R.
ASLANER
Department of Mathematics, Inönü University, 44280 Malatya, Turkey
10.22099/ijsts.2005.2810
In this paper, the time-like hyperruled surfaces in the Minkowski 4-space and their algebraic<br />invariants are worked. Also some characteristic results are found about these algebraic invariants.
ruled surfaces,rulings,main curvature,scalar curvature,time-like vector
http://ijsts.shirazu.ac.ir/article_2810.html
http://ijsts.shirazu.ac.ir/article_2810_2fdadc0f5858b8c7c132ee7ac3a6e46b.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
ANGULAR DEPENDENT MAGNETORESISTANCE OSCILLATION IN STAGE-2 IBr GRAPHITE INTERCALATION COMPOUND
349
356
EN
M.
BARATI
Department of Physics, Shiraz University, Shiraz, I. R. of Iran 71454
P. K.
UMMAT
Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
G.
LUKE
Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
W. R.
DATARS
Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
10.22099/ijsts.2005.2811
The angular dependent magnetoresistance oscillation (ADMRO) of the stage-2 IBr graphite<br />intercalation compound (GIC) was studied between 1.8 K and 110 K in magnetic fields between 1 and 9<br />T. There was a series of peaks in the c-axis resistance as the field direction was changed from the c axis<br />to the (001) plane. The field independence of the angular positions of the peaks, showing that the<br />oscillation is not from the Shubnikov-de Haas effect, and the presence of the oscillation at high<br />temperatures indicate that the effect is semiclassic. The location and the relative amplitudes of the peaks<br />show that the ADMRO in this compound does not follow the predictions for the symmetrical corrugation<br />model of the cylindrical Fermi surface. The reason is attributed to the presence of two cylindrical Fermi<br />surfaces and zone folding of the Fermi surface by the periodicity of the IBr lattice in this compound.
Graphite intercalation compound,ADMRO effect
http://ijsts.shirazu.ac.ir/article_2811.html
http://ijsts.shirazu.ac.ir/article_2811_d5686fab19aa01ed8a1a7bfb69baa70b.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
ON GENERAL RELATIVELY ISOTROPIC L-CURVATURE FINSLER METRICS
357
366
EN
B.
NAJAFI
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
A.
TAYEBI
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
M. M.
REZAII
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
10.22099/ijsts.2005.2812
In this paper the general relatively isotropic L -curvature Finsler metrics are studied. It is<br />shown that on constant relatively Landsberg spaces, the concepts of weakly Landsbergian, Landsbergian<br />and generalized Landsbergian metrics are equivalent. Some necessary conditions for a relatively<br />isotropic L -curvature Finsler metric to be a Riemannian metric are also found.
Finsler metric,(generalized) Landsberg metric,(mean) landsberg curavture,(mean) Cartan tensor,Douglas tensor,Funk metric,Randers metric
http://ijsts.shirazu.ac.ir/article_2812.html
http://ijsts.shirazu.ac.ir/article_2812_3ec2d485739429c1284f819a17e1ed16.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
ELECTRON ACCELERATION AND EXCITATION PROCESSES IN THE VICINITY OF A MERCURY DISCHARGE CONSTRICTION
367
375
EN
S.
FAZLIAN
1Faculty of Physics, University of Tabriz, Tabriz, I. R. of Iran,
S.
SOBHANIAN
Faculty of Physics, University of Tabriz, Tabriz, I. R. of Iran
A.
MURADOV
Physics Dept., Baku State University, Baku, Azerbaijan
10.22099/ijsts.2005.2813
In the present paper axial distributions of plasma and floating potentials, electron and ion<br />densities and EEDF have been measured in the DL region of a Hg discharge constriction. An attempt has<br />been made for the resolution of opposing charged layer structures in DL. Excitation processes in the<br />constriction region are studied. Using the linearization method for the nonstationary balance equations<br />system and choosing appropriate discharge conditions, the step excitation rate by the electron impact for<br />6 3 P 2 →7 1 S 0 transition in Hg is determined.
Double layers (DL),EEDF,plasma parameters,excitation processes,constriction edge,excitation
rates,modulation depths,spectral lines
http://ijsts.shirazu.ac.ir/article_2813.html
http://ijsts.shirazu.ac.ir/article_2813_af8332e94ffa5ce5f445ce6c441a01ca.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
INFORMATION MATRIX FOR A MIXTURE OF TWO PARETO DISTRIBUTIONS
377
385
EN
S.
NADARAJAH
1Department of Statistics, University of Nebraska, Lincoln, NE, USA, 68583
S.
KOTZ
Department of Engineering Management and Systems Engineering,
George Washington University, Washington, D. C. USA, 20052
10.22099/ijsts.2005.2814
The Fisher information matrix for a mixture of two Pareto distributions is derived. Numerical<br />tabulations of the matrix are also provided for practical purposes. The work is motivated by a real-life<br />example.
Lerch function,pareto distribution
http://ijsts.shirazu.ac.ir/article_2814.html
http://ijsts.shirazu.ac.ir/article_2814_69a91a8da9260173b19ae6d68b85daaa.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
EFFECT OF MONITORING TIME INTERVAL ON THE RESULTS OF STOCHASTIC ANALYSIS OF KARST WATER RESOURCES
387
399
EN
M.
ZARE
Department of Geology, Shiraz University, I. R. of Iran
2Department of Statistics, Shiraz University, I. R. of Iran
A. R.
NEMATOLLAHI
Department of Statistics, Shiraz University, I. R. of Iran
M.
RAHNEMAEI
Department of Irrigation, Shiraz Islamic Azad University, I. R. of Iran
10.22099/ijsts.2005.2815
Data monitoring is important in the study and analysis of hydrological behaviors of karstic<br />systems. Monitoring shows the various regimes of groundwater flow (laminar or turbulent), depletion,<br />filling, filtration and karstification degree of karst aquifers. In recent years, analyses of these data had<br />considerable advances using stochastic time series analyses. An important problem related to these<br />analyses is the constraint of financial and technical human support. If we can increase the time intervals,<br />the costs are lowered and development of new monitoring networks will be possible. In this research, the<br />effect of monitoring time intervals on the results of time series analysis and calculated hydrologic delay<br />times are studied, using bivariate analyses in spectral domain. The first (shorter) and the second (longer)<br />delay times are related to the flow of groundwater through the larger and smaller fractures of the karstic<br />system, respectively. Daily groundwater level data of three piezometers and the discharge of a spring in<br />the Maharlu karst basin in Iran (5212′ to 5328′E and 291′ to 306′N ) were acquired and then six<br />different time series having different time intervals (1, 3, 7, 10, 14 and 30 days) were extracted and<br />analyzed. The results show that the variation of the computed stochastic parameters with increasing time<br />intervals is unpredictable, but the variation of time (period) corresponding to the frequency at the peak of<br />amplitude function (curve) shows a linear and predictable relationship, which is unique for every kind of<br />karstic aquifer having different degrees of karstification.
Karst,Time series,squared coherency,phase,amplitude,delay time
http://ijsts.shirazu.ac.ir/article_2815.html
http://ijsts.shirazu.ac.ir/article_2815_e4d792d269fba9a9da978a1f80d5196a.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
A NEW METHOD FOR ELECTRIC FIELD OPTIMIZATION IN HIGH POWER LASER MULTILAYERS
401
410
EN
M. H.
MAHDIEH
Department of Physics, Iran University of Science and Technology, Narmak, Tehran, I. R. of Iran
M.
ALAVI-NEJAD
Department of Physics, Iran University of Science and Technology, Narmak, Tehran, I. R. of Iran
10.22099/ijsts.2005.2816
Spatial distribution of electric field amplitude has an essential role in laser-induced damage<br />multi-layer coating. A new method introduced in this paper to reduce the electric field intensity<br />effectively within the high index layers in multi-layer reflectors that are irradiated by high power lasers.<br />The design is based on specific non-quarter wave pairs, assuming the number of layers is held constant.<br />Using a combination of periodic and non-periodic pairs of a non-quarter wave stack with an appropriate<br />thickness for a specific angle of incidence, minimum electric field can be obtained within the high index<br />layers for the S or P polarization. Different results can be obtained if the non-periodic pairs are placed<br />adjacent to the substrate, or to the ambient. We have shown that by the former design, a lower electric<br />field can be achieved within the layers and the mirror can be optimized. The optimization was carried<br />out for oblique incidence and the effect of angle of incidence was examined for both S and P<br />polarizations.
Optical multi-layers,high power laser mirrors,optical damage,electric field reduction
http://ijsts.shirazu.ac.ir/article_2816.html
http://ijsts.shirazu.ac.ir/article_2816_1faf57c21d8441ae18e765ab67979c52.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
EXTREMAL ORDERS INSIDE SIMPLE ARTINIAN RINGS
411
420
EN
N. H.
HALIMI
84 Manburgh Tce, Darra, QLD 4076, Australia
10.22099/ijsts.2005.2817
The aim of this paper is to study orders over a valuation ring V with arbitrary rank in a<br />central simple F-algebra Q. The relation between all of the orders is explained with a diagram. It is then<br />shown that inside Bezout order, extremal V-orders are precisely semi-hereditary. In the last section, the<br />effect of Henselization on maximal and semi-hereditary orders is examined.
Dubrovin valuation rings,extremal orders,Henselization
http://ijsts.shirazu.ac.ir/article_2817.html
http://ijsts.shirazu.ac.ir/article_2817_62d19d2ec79077ab2b70dcc65e62f64a.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
12
28
ON THE INVESTIGATION OF SPARK FORMATION CONDITIONS AND ENERGY GAIN IN INERTIAL CONFINEMENT FUSION
421
431
EN
A.
GHASEMIZAD
1Department of Physics, Faculty of Science, University of Guilan, Rasht, I. R. of Iran,
M. R.
ESKANDARI
Department of Physics, Shiraz University, Shiraz, I. R. of Iran
S.
KHOSHBINFAR
Department of Physics, Faculty of Science, University of Guilan, Rasht, I. R. of Iran
M.
KAMRAN
Department of Physics, Faculty of Science, University of Guilan, Rasht, I. R. of Iran
10.22099/ijsts.2005.2818
In isobaric models for inertial confinement fusion it is assumed that the target configuration<br />at stagnation time (maximum compression) consists of two regions, hot spark and cold fuel, respectively.<br />Here the conditions of spark formation and ignition in hydrogen equimolar isotopes in central spark<br />ignition are investigated and permissible values of Hs and Ts are evaluated numerically. By introducing a<br />dimensionless parameter, ψs, the class of targets are considered by the specific value of ψs. Finally,<br />limiting fuel energy gain curve (Gf*) as a function of ignition energy (Eign) allows different implosion<br />velocities to be calculated. This result is in good agreement with more complex hydrodynamic models.
Central spark ignition,spark parameter,isobaric model,limiting gain curve
http://ijsts.shirazu.ac.ir/article_2818.html
http://ijsts.shirazu.ac.ir/article_2818_e2c40591159c56838c97453e3778604e.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
USING FUZZY KNOWLEDGE OF A NUISANCE PARAMETER FOR HYPOTHESIS TESTING
433
454
EN
J.
BEHBOODIAN
1Department of Mathematics, Shiraz Islamic Azad University, Shiraz, I. R. of Iran
behboodian@stat.susc.ac.ir,
A.
MOHAMMADPOUR
Department of Statistics, Faculty of Mathematics and Computer Science, Amirkabir University of Technology,
424 Hafez Ave., Tehran, I. R. of Iran, 15914
10.22099/ijsts.2005.2819
The problem of hypothesis testing with a nuisance parameter is considered. Two methods for<br />using fuzzy knowledge on the nuisance parameter to test hypotheses are suggested. These methods are<br />neither a pure classical nor a pure Bayesian approach to hypothesis testing, but rather related to both. A<br />few known examples and their applications, which cannot be studied by the parametric statistical<br />methods, are discussed.
Fuzzy Statistics,defuzzified distribution,weighted defuzzification-Estimator,exchangeable
normal Distribution
http://ijsts.shirazu.ac.ir/article_2819.html
http://ijsts.shirazu.ac.ir/article_2819_7710b20c222e8a91298a9202beade963.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
ON THE INTEGRAL INVARIANTS OF KINEMATICALLY GENERATED RULED SURFACES
455
470
EN
H. B.
KARADAG
Department of Mathematics, Faculty of Sciences and Arts, Inönü University,
44069 Malatya, Turkey
S.
KELES
Department of Mathematics, Faculty of Sciences and Arts, Inönü University,
44069 Malatya, Turkey
10.22099/ijsts.2005.2820
In this paper, the dual area vector of a closed dual spherical curve is kinematically generated<br />and the dual Steineer vector of a motion are extensively studied by the methods of differential geometry.<br />Jacobi’s Theorems, known for real curves, are investigated for closed dual curves. The closed trajectory<br />surfaces generated by an oriented line are fixed in a moving rigid body in IR3 , in which the closed dual<br />curves from E. Study’s transference principle is studied. The integral invariants of these closed ruled<br />surfaces are calculated by means of the area vector. Moreover, some theorems, results and examples are<br />given.
Mechanism,kinematics,area vectors,ruled surfaces,invariants and motions
http://ijsts.shirazu.ac.ir/article_2820.html
http://ijsts.shirazu.ac.ir/article_2820_8a3f1287b2fff270d6c689fd8bbe547e.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
AIR POLLUTION ASSESSMENT IN SHIRAZ BY PASSIVE SAMPLING TECHNIQUES
471
480
EN
K.
HADAD
1Department of Nuclear Engineering, Shiraz University, Shiraz, I. R. of Iran, 71345
hadadk@shirazu.ac.ir
A.
SAFAVI
Department of Chemistry, Shiraz University, Shiraz, I. R. of Iran, 71454
R.
TAHON
ETI Group Burgeap, 92772 Boulogne Billancourt Cedex, France
10.22099/ijsts.2005.2821
The air quality in Shiraz was assessed based on a one-week passive sampling campaign.<br />During the first week of the summer 2003, about 400 passive samplers were used in groups of two and<br />three, so that 187 sampling stations covered all of Shiraz. Pollutant gases including SO2, NO2 and BTX<br />(benzene, toluene and xylene) were sampled by diffusive sampling tubes. Collected samples were<br />analyzed and pollutant concentrations were determined by using ion chromatography, spectrophotometry<br />and gas chromatography techniques. The result of the analysis shows that SO2 and NO2 concentrations<br />exceed national and international standards in the central and southern parts of Shiraz. Weekly averaged<br />concentrations of benzene, toluene and xylene at all sampling sites were 105, 206 and 123 μg/m3, which<br />exceed national and international standards.<br />Based on the results, more than 15% of Shiraz's population (180,000 out of 1.2 million people)<br />were exposed to high levels of NO2 during this survey period.
Urban air pollution,passive sampling,air quality,BTX concentration
http://ijsts.shirazu.ac.ir/article_2821.html
http://ijsts.shirazu.ac.ir/article_2821_fdda54545c67a6cf90ba3218724b577c.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
TRANSFORMATION SEMIGROUPS AND EXACT SEQUENCES
481
495
EN
F.
AYATOLLAH ZADEH SHIRAZI
Department of Mathematics, Faculty of Science, University of
Tehran, Enghelab Ave., Tehran, I. R. of Iran
10.22099/ijsts.2005.2822
This text carries out some ideas about exact and P− exact sequences of transformation<br />semigroups. Some theorems like the short five lemma (Lemma 1.3 and Lemma 2.3) are valid here as in<br />exact sequences of R − modules.
a − minimal set,exact sequence,P− exact sequence,proximal relation,transformation semigroup
http://ijsts.shirazu.ac.ir/article_2822.html
http://ijsts.shirazu.ac.ir/article_2822_838138855031870967c60812ee721d3f.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
ON GENERAL RELATIVELY ISOTROPIC MEAN LANDSBERG METRICS
497
505
EN
B.
NAJAFI
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
A.
TAYEBI
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
M. M.
REZAII
Department of Mathematics and Computer Science
of Amir-Kabir University, Tehran, I. R. of Iran
10.22099/ijsts.2005.2823
The general relatively isotropic mean Landsberg metrics contain the general relatively<br />isotropic Landsberg metrics. A class of Finsler metrics is given, in which the mentioned two concepts<br />are equivalent. In this paper, an interpretation of general relatively isotropic mean Landsberg metrics is<br />found by using C-conformal transformations. Some necessary conditions for a general relatively<br />isotropic mean Landsberg metric, as well as generalized Landsberg metric to be a Riemannian metric are<br />also found.
Finsler structure,Cartan connection,(generalized) Landsberg metric,scalar curvature,C2-like
space,c-conformal transformation
http://ijsts.shirazu.ac.ir/article_2823.html
http://ijsts.shirazu.ac.ir/article_2823_90a1f40868e91842e0619d4d84578a41.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
THE STRUCTURE OF (α,β)-DERIVATIONS OF TRIANGULAR RINGS
507
514
EN
M. N.
GHOSSEIRI
Department of Mathematics, Kurdistan University
P. O. Box 416, Sanandaj, I. R. of Iran
10.22099/ijsts.2005.2824
Let R and S be reduced rings with identities whose idempotents are central, and let M be an<br />(R, S)-bimodule such that annr (M)=0. In this paper, we determine first the structure of automorphisms of<br />the triangular ring, <br /><br /><br /><br /><br />=<br />S<br />R M<br />T<br />0<br />, and then, for all automorphisms α ,β of T we determine the structure<br />of (α,β)-derivations of T.
Triangular ring,automorphism,(α,β ) -derivation
http://ijsts.shirazu.ac.ir/article_2824.html
http://ijsts.shirazu.ac.ir/article_2824_9c3c1808dd2dab02b817767301f7eb17.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
INSTABILITY OF SOLUTIONS OF CERTAIN NONLINEAR VECTOR DIFFERENTIAL EQUATIONS OF ORDER SEVEN
515
521
EN
C.
TUNC
1Department of Mathematics, Faculty of Sciences and Literature,
Yüzüncü Yil University, 65080, Van, Turkey
E.
TUNC
Department of Mathematics, Faculty of Science and Literature,
Gaziosman Paşa University, 60080, Tokat, Turkey
10.22099/ijsts.2005.2825
Sufficient conditions are established under which the zero solution X = 0 of equation (2) is<br />unstable.
Nonlinear differential equations,seventh order,instability,Lyapunov’s second (direct) method
http://ijsts.shirazu.ac.ir/article_2825.html
http://ijsts.shirazu.ac.ir/article_2825_a8ec38612da6961acdeef265e22fd009.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
ON THE MOMENTS OF LKD
523
529
EN
A
BAZARGAN-LARI
Department of Statistics, Shiraz University, Shiraz, I. R. of Iran
10.22099/ijsts.2005.2826
The mean and variance of the Lagrangian Katz family of distribution (LKD), the basic<br />Lagrangian Katz distribution of Type I (LKD-I) and Type II (LKD-II) are provided in an easy method.<br />The recurrence relation between the non-central, central and factorial moments, and the recurrence<br />relation between moments and cumulants of LKD, LKD-I and LKD-II are given. The first four<br />cumulants of LKD-I and LKD-II are provided.
Lagrangian Katz Family of Distribution (LKD),recurrence relations,central,non-central and
factorial moments,cumulants
http://ijsts.shirazu.ac.ir/article_2826.html
http://ijsts.shirazu.ac.ir/article_2826_e500a7576eb164d442bdb20b3d6415b8.pdf
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
29
3
2005
02
27
CONFORMAL VECTOR FIELDS ON TANGENT BUNDLE OF A RIEMANNIAN MANIFOLD
531
539
EN
S.
HEDAYATIAN
Faculty of Mathematics, Amir-Kabir University of Technology, Hafez Ave. 15914, Tehran, I. R. of Iran
B.
BIDABAD
Faculty of Mathematics, Amir-Kabir University of Technology, Hafez Ave. 15914, Tehran, I. R. of Iran
10.22099/ijsts.2005.2827
Let M be an n-dimensional Riemannian manifold and TM its tangent bundle. The<br />conformal and fiber preserving vector fields on TM have well-known physical interpretations and have<br />been studied by physicists and geometricians. Here we define a Riemannian or pseudo-Riemannian lift<br />metric g on TM , which is in some senses more general than other lift metrics previously defined on<br />TM , and seems to complete these works. Next we study the lift conformal vector fields on (TM,g) and<br />prove among the others that, every complete lift conformal vector field on TM is homothetic, and<br />moreover, every horizontal or vertical lift conformal vector field on TM is a Killing vector.
Complete lift metric,Conformal,Homothetic,Killing and Fiber-preserving vector fields
http://ijsts.shirazu.ac.ir/article_2827.html
http://ijsts.shirazu.ac.ir/article_2827_9795fa11b38852d02d951bd9f80126d8.pdf