eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
229
245
10.22099/ijsts.2005.2799
2799
SOME SPECTRAL PROPERTIES OF STURM-LIOUVILLE PROBLEM WITH TRANSMISSION CONDITIONS
M. KADAKAL
1
O. SH. MUKHTAROV
2
F. S. MUHTAROV
3
Ondokuz Mayis University, Science and Arts Faculty, Department of Mathematics 55139 Kurupelit, Samsun, Turkey
Gaziosmanpasa University, Science and Arts Faculty, Department of Mathematics 60000-Tokat-Turkey
Azerbaijan Science Academy, Mathematics and Mechanic Institute, Baku-Azerbaijan
We investigate the boundary-value problem generated by the Sturm-Liouville equation with<br />discontinuous coefficients, eigenparameter dependent boundary conditions and transmission conditions<br />at the point of discontinuity. With a different approach we introduce an adequate Hilbert space<br />formulation, investigate some properties of eigenvalues, Green’s function and resolvent operator, and<br />find simple conditions on the coefficients which guarantee the self-adjointness of the considered<br />problem.
http://ijsts.shirazu.ac.ir/article_2799_0eceb32895a9fc2db9c0606e88ce221e.pdf
Sturm-Liouville problem
eigenvalue
eigenfunction
Green’s function
resolvent operator
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
247
257
10.22099/ijsts.2005.2800
2800
NUMERICAL EVALUATION OF THREE-STEP SELECTIVE PHOTO-IONIZATION OF GD157 AND GD155 ISOTOPES
M. H. MAHDIEH
1
F. MARSUSI
2
Department of Physics, Iran University of Science and Technology, Narmak, Tehran, I. R. of Iran
Department of Physics, Iran University of Science and Technology, Narmak, Tehran, I. R. of Iran
A three-step selective photo-ionization for Gd155 and Gd157 isotopes by pulsed laser was<br />evaluated numerically. Due to large thermal neutron absorption cross sections, these two isotopes in<br />natural gadolinium are good candidates as burnable poison to control reactivity early in the fuel cycle<br />and allow extended fuel burn up. Rate equations have been used to calculate the dynamics of the isotope<br />populations, ionization rate, and selection factor. Doppler broadening, as well as power broadening for<br />atomic energy levels, has been considered in the calculations. The effects of laser intensity, frequency<br />bandwidth, and laser detuning in the ionization process have also been assessed. By applying a variety of<br />conditions, the sensitivity of different parameters in the ionization process was investigated. The results<br />show that the ionization yield increases with the intensities of lasers, and becomes saturated at some<br />specific values. Depending on the energy bandwidth of each state, laser bandwidth and the detuning of<br />lasers greater than particular values can affect the ionization yield. Due to small and finite isotope shifts<br />of energy states, the selection factor can be influenced by detuning and laser bandwidth. From the<br />results, it can be inferred that for Gd155 and Gd157 isotopes, ionization is more sensitive to the first and<br />second laser bandwidth and detuning. From these results, optimum selection factors and ionization by<br />using appropriate laser intensities, bandwidth, and detuning can be achieved.
http://ijsts.shirazu.ac.ir/article_2800_6783d339295fe8a6a346e2fe6469fd00.pdf
Photo-ionization
multi-step photo-ionization
selective photo-ionization
pulse laser
photon-atom
interaction
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
259
269
10.22099/ijsts.2005.2801
2801
DISTRIBUTION FUNCTIONS IN LIGHT OF THE UNCERTAINTY PRINCIPLE
S. NASIRI
1
Department of Physics, Zanjan University, Zanjan, I. R. of Iran and Institute for Advanced Studies in Basic Sciences, IASBS, Zanjan, I. R. of Iran
Here, we have considered the Husimi and Wigner distribution functions. We have, in<br />particular, shown how the uncertainty principle works for the two cases of simple and damped harmonic<br />oscillators when either of these two distributions are used. The conclusion shows that the Husimi<br />distribution function remains non-negative through the phase space but it does not always satisfies the<br />uncertainty principle. On the other hand the Wigner distribution function while becoming negative in<br />certain regions of the phase space do not violate the uncertainty principle.
http://ijsts.shirazu.ac.ir/article_2801_f466608f51bf7b8e13ac047be9a03fe7.pdf
Distribution functions
uncertainty principle
damped harmonic oscillator
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
267
276
10.22099/ijsts.2005.2802
2802
A NEW DIGITAL PROTECTIVE RELAY BASED ON FUZZY LOGIC AND VALUE ESTIMATION
K. ERENTURK
1
Dept. of Electrical Eng., Faculty of Engineering, Ataturk University, 25240, Erzurum, Turkey
In this paper, design and application of a new digital protective relay based on fuzzy logic<br />and value estimation to a radial power system protection was presented. A novel approach based on<br />value estimation was investigated for the proposed fuzzy logic based protective relay. In addition to the<br />theoretical aspect of fuzzy logic, mathematical definition of value estimation, detection and<br />measurement of faulty current, determination of its duration, decision mechanism and detailed system<br />architecture were also introduced. The examined technique based on fuzzy logic and value estimation to<br />control the protection action of the protective relay was intended to improve the performance of a<br />conventional protective relay control for human safety and system reliability with the use of a fuzzy<br />logic controller. The difference between estimated and sampled values was used to form the rule base.<br />Proposed relay architecture was used as a detector and was developed to predict faults and to protect<br />particular sections of a designed prototype radial power system at an early stage. Performance analysis<br />was made, and related results and discussion were given.
http://ijsts.shirazu.ac.ir/article_2802_dff05c556a1cfc46eba1def4f52a3cfb.pdf
Value estimation
fuzzy control
AC transmission
fault detection
digital protective relay
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
277
285
10.22099/ijsts.2005.2803
2803
KAON ELECTROPRODUCTION OFF PROTON
N. GHAHRAMANY
1
M. GHANAATIAN
2
Department of Physics, Shiraz University, Shiraz, I. R. of Iran, 71454
Department of Physics, Shiraz University, Shiraz, I. R. of Iran, 71454
The elementary reaction of kaon exclusive electroproduction on protons has been studied in<br />a broad kinematical range. Data for the calculation of the form factor of the kaon have been taken at<br />different values of the invariant center of mass energy W in the range W=1.8, 1.85, 1.98, 2.08 (GeV), for<br />one value of the transferred 4-momentum Q2=2.35 (GeV/c)2. In this analysis, we calculated σL and σT by<br />using the Rosenbluth separation. Then the electromagnetic kaon form factor was calculated by Chew-<br />Low extrapolation.
http://ijsts.shirazu.ac.ir/article_2803_0f6f47533b5d067529237bed3f5eeea9.pdf
Electroproduction
kaon
form factor
rosenbluth separation
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
287
294
10.22099/ijsts.2005.2804
2804
AN INFLUENCE APPROACH FOR SENSITIVITY ANALYSIS OF NON-RANDOM DROPOUT BASED ON THE COVARIANCE STRUCTURE
M. GANJALI
1
M. REZAEI
2
Dept. of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, I. R. of Iran
Dept. of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, I. R. of Iran
A generalized Heckman model is used for the joint modeling of longitudinal continuous<br />responses and dropout in order to see the influence of a small perturbation of the elements of the<br />covariance structure on displacement of the likelihood. The perturbation from random dropout in the<br />direction of informative dropout is considered for Mastitis data.
http://ijsts.shirazu.ac.ir/article_2804_19ba27e6efbe5227014b5b2cf3be6803.pdf
Longitudinal data
Informative dropout
Sensitivity analysis
Generalized Heckman model
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
296
304
10.22099/ijsts.2005.2805
2805
EXISTENCE RESULTS FOR A CLASS OF SEMILINEAR ELLIPTIC BOUNDARY VALUE PROBLEMS
G. A. AFROUZI
1
M. JAFARI
2
Department of Mathematics, Faculty of Basic Sciences Mazandaran University, Babolsar, I. R. of Iran
Department of Mathematics, Faculty of Basic Sciences Mazandaran University, Babolsar, I. R. of Iran
We consider the semilinear elliptic boundary value problem<br /> <br />= ∈∂Ω<br />− Δ = ∈Ω<br />u x x<br />u x f u x x<br />( ) 0;<br />( ) λ ( ( ));<br />where λ > 0 is a parameter, Ω is a bounded region in RN with a smooth boundary, and f is a<br />smooth function. We prove, under some additional conditions, the existence of a positive solution for λ<br />large. We prove that our solution u for λ large is such that = →∞<br />∈Ω<br />|| u ||: sup| u(x) |<br />x<br />as λ →∞.<br />Also, in the case of N = 1, we use a bifurcation theory to show that the solution is unstable.
http://ijsts.shirazu.ac.ir/article_2805_2d6e26f33852e5572e87420cc59103b7.pdf
Semilinear elliptic problem
positive solution
unstable solution
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
305
317
10.22099/ijsts.2005.2806
2806
APPLICATION OF FUZZY LOGIC TO A LEAKAGE CURRENT RELAY
K. ERENTURK
1
Dept. of Electronic Eng., Engineering Faculty, Ataturk University, 25240, Erzurum, Turkey
The design and application of a fuzzy logic based controller to a leakage current relay was<br />presented in this paper. A novel approach based on fuzzy logic to form the tripping action of leakage<br />current relay was investigated. In addition to the theoretical aspect of fuzzy logic, detection of a leakage<br />current, measurement of the leakage current, determination of its duration, trip opening of faulty cases<br />and detailed system architecture were also introduced. The inspected fuzzy logic technique to control the<br />tripping action of the leakage current relay was intended to improve the performance of conventional<br />leakage current relay control for human safety and system reliability. The relationship between the<br />controlled output of the fuzzy processor and properties of leakage current for the proposed relay was<br />explored by using a graphical output expression. It was observed that the proposed leakage current relay<br />based on fuzzy logic was more reliable than conventional leakage current relay.
http://ijsts.shirazu.ac.ir/article_2806_9cf246559be6c56d0e063e85534ad50e.pdf
Fuzzy Logic
leakage current relay
intelligent protection
rule-base design
radial power system
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
319
323
10.22099/ijsts.2005.2807
2807
THE COHERENT ANOMALY METHOD IN THE STUDYING OF THE S=1 ISING CHAINS WITH LONG-RANGE INTERACTION
A. RAMAZANI
1
Department of Physics, Kashan University, Kashan, I. R. of Iran
The coherent anomaly method and a cluster mean-field approach combined with finite-size<br />scaling extrapolation were used to determine the critical temperature and the critical exponents of a<br />S =1 Ising chain with a long-range interaction in the form of 1/ r1+σ . The results of critical<br />temperature are in good agreement with the recent results of the finite-range scaling method and are<br />more accurate in the classical region. The critical exponents are in agreement with the results of spin-<br />2<br />1<br />Ising chains and indicate that the critical exponents are independent of the magnitude of spin in Ising<br />models with long-range interactions.
http://ijsts.shirazu.ac.ir/article_2807_b6e06d438a3252aae04d715ebd880f56.pdf
Coherent anomaly
critical phenomena
critical exponents
Ising model
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2005-09-01
29
2
325
333
10.22099/ijsts.2005.2808
2808
A STUDY ON TIME-LIKE COMPLEMENTARY RULED SURFACES IN THE MINKOWSKI n-SPACE
M. TOSUN
tosun@sau.edu.tr
1
M. A. GUNGOR
2
Department of Mathematics, Sakarya University, Sakarya, Turkey
Department of Mathematics, Sakarya University, Sakarya, Turkey
For the first time in the Minkowski space, an Rn 1 time-like complementary ruled surface is<br />described and relations are given connected with an asymptotic and tangential bundle of the time-like<br />complementary ruled surface. Furthermore, theorems are given related to edge space, central space and<br />central ruled surface of this complementary ruled surface.
http://ijsts.shirazu.ac.ir/article_2808_40bc362abe927726aa6b793686d16a2b.pdf
Minkowski space
ruled surfaces
complementary ruled surfaces