019396   Javaid S;Maqbool S (Statistics & O.R. Dep, A. M. U., Aligarh-202 002, Email: shakeel.jd@gmail.com) : Improved ratio estimator using non-conventional location parameter in ranked set sampling. Int J agric statist Sci 2017, 13(2), 453-5.

In most sample surveys, a reasonable number of the sampling units (eg. households, businesses, etc.) can be ordered fairly accurately with respect to a variable of interest without actual measurement, and at little cost. However, exact measurement of these units may be very tedious and/or expensive. Ranked Set Sampling (RSS), as proposed by McIntyre (1952), provides an alternative to simple random sampling (SRS) in these situations. The feature of RSS is that it combines SRS with other sources of information such as professional knowledge, judgment, auxiliary information, etc., to yield more representative measurements from the population. Ranked set sampling (RSS) is a method of collecting data that improves estimation by utilizing the sampler's judgment or auxiliary information about the relative sizes of the sampling units. It can be applied in many studies where exact measurement of an element is very difficult, but the variable of interest can be relatively easily ranked. In this paper, improved ratio estimator using non-conventional location parameter of an auxiliary variable is developed for population mean in ranked set sampling. Mean square error of the proposed estimator is obtained and compared with traditional ratio rank set sampling.

7 ref

019395   Hungund C P S;Kulkarni V S (Statistics Dep, Gulbarga Univ, Kalaburagi-585 106, Email: cpshgu2@gmail.com) : Factor approach for the analysis of stress factors of working women of the three districts of Karnataka state. Int J agric statist Sci 2017, 13(2), 417-22.

The present study investigates the most decisive factors contributing to stress and the level of occupational stress among working women through factor analysis by using SPSS 20 software. There were six occupational stress factors identified viz. ; salary/wage availability in time, leave/gap availability in time, work satisfaction level, heavy physical work, colleague support and opportunity to improve the economic level to analyze in this study. Descriptive Statistics and Exploratory Factor Analysis (EFA) were used to analyze the data.

1 illus, 9 tables, 5 ref

019394   Handique L;Chakraborty S (Statistics Dep, Dibrugarh Univ, Dibrugarh-786 004, Email: handiquelaba@gmail.com) : Beta generalized Marshall-Olkin Kumaraswamy-G family of distributions with applications. Int J agric statist Sci 2017, 13(2), 721-33.

A family of continuous probability distribution is proposed by plugging the Kumaraswamy-G (Kw - G) distribution as the base line distribution in the Beta Generalized Marshall-Olkin-G (BGMO - G) family. Some known families are obtained as special cases. The probability density function and the cumulative distribution function of the proposed family is expressed as infinite mixtures of the Kw - G distribution. Probability density function of order statistics, probability weighted moments, moment generating function, Renyi entropy, quantile function and asymptotes are studied. The parameter estimation by method of maximum likelihood is presented. Finally, the proposed model is compared to its sub models by considering one example of real life data modeling.

3 illus, 1 table, 33 ref

019393   Gupta R;Bhardwaj P (Statistics Dep, Ch. Charan Singh Univ, Meerut-250 004, Email: prgheadstats@yahoo.in) : Analysis of a discrete parametric markov-chain model of a two unit warm standby system with arrival time of repairman. Int J agric statist Sci 2017, 13(2), 445-52.

This paper deals with the cost-benefit analysis of a two-identical unit warm standby system model assuming two modes- normal and total failure of each unit. Initially, the repairman is not available with the system. He is called to come at the system whenever required and he takes some significant time to reach the system. The random variables denoting failure time, repair time and arrival time of repairman at the system follow geometric distributions with different parameters. The various measures of system effectiveness are obtained by using regenerative point technique.

3 illus, 11 ref

019392   Godase S S;Shirke D T;Kashid D N (Statistics Dep, SGM College, Karad, Satara-415 124, Email: suwarna_godase@rediffmail.com) : Prediction and tolerance intervals for the lifetime distribution of K-unit parallel system based on generalized variable approach. Int J agric statist Sci 2017, 13(2), 663-72.

In this article, we consider the problem of setting prediction interval for future sample, when lifetime distribution of a unit in a k-unit parallel system has exponential distribution based on generalized variable(GV) approach. We also discuss one sided tolerance limits and tolerance intervals based on GV approach. Performance of both intervals are studied using simulation and compared them with existing ones to exhibit superiority of the proposed method. The prediction interval is illustrated through real life data.

9 tables, 27 ref

019391   Fitriani R;Sumarminingsih E;Astutik S (Statistics Study Programme, Brawijaya Univ, Malang, Indonesia, Email: rahmafitriani@ub.ac.id) : Spatial panel dynamic econometrics model of land value case study of land use externalities and their dynamic in the Jakarta's fringe. Int J agric statist Sci 2017, 13(2), 645-54.

Land value is the product of past decision of its use. It is also affected by the observed externalities. The effect of each factor on land value has dynamic and spatial virtues, which can be captured based on an empirical model using a spatial panel dynamic setting. The model is useful to estimate the extent and the dynamic nature of land use externalities, important information to formulate an effective urban growth - 21 - management's policy. The objective of this paper is to derive the instant and the dynamic indirect effects - externalities on land value.The result is applied to analyse the significance of land use externalities on agricultural land value in the Jakarta's fringe. The analysis indicates the significance of the negative externalities, the previous land value and the local accessibility. The effects are accumulated dynamically over years, but they will fully affect the land value after 6 years.

4 illus, 4 tables, 22 ref

019390   Dwivedi S;Siddiqui S A (Mathematics Dep, IT Unit, Higher College Technology, Muscat, Sultanate of Oman, Email: k.getshradha@gmail.com) : Bayes estimator of scale parameter of size-biased Mukherjii-Islam (SBMID) by Lindley's approach. Int J agric statist Sci 2017, 13(2), 753-8.

Authors have obtained Bayes estimator of scale parameter of SBMID using Lindley's approach of estimation. We have taken four priors un der Squared Error Loss Function and Asymmetric Precautionary Loss Function.

2 tables, 6 ref

019389   Dargopatil P M;Ghute V B (Statistics Dep, Solapur Univ, Solapur-413 255, Email: vbghute_stats@rediffmail.com) : Effect of autocorrelation on performance of the S chart. Int J agric statist Sci 2017, 13(2), 465-72.

Monitoring the variability of a process is as important as monitoring its mean. The Shewhart S chart is commonly used in many manufacturing industries to monitor the process variability. This chart assumes that generated process data are normally and independently distributed. The assumption of independence may be unrealistic in industries, as many processes inherently produce autocorrelated data. In this paper, we investigate the effect of autocorrelation on the statistical performance of the S chart. The first-order autoregressive (AR (1)) process is used to model the data from an autocorrelated process of interest. The ARL performance of the S chart for variability derived independent observations is compared with autoregressive process AR (1) with different degrees of correlation. It is found that the correlation structure increases the rate of false alarm of the S chart. Also, the chart is found much less sensitive in detecting changes in the process standard deviation.

1 illus, 14 tables, 9 ref

019388   Chauhan S K;Malik S C (Statistics Dep, M. D. Univ, Rohtak-124 001, Email: statskumar1@gmail.com) : Reliability and MTSF evaluation of series-parallel configuration using weibull failure laws. Int J agric statist Sci 2017, 13(2), 759-70.

In this paper, the main stress is on the evaluation of reliability measures of a series-parallel system by considering Weibull failure laws. For non-identical components, the expressions for mean time to system failure (MTSF) and reliability of the system are derived. Using R-software, the results for these reliability measures are obtained for arbitrary values of the parameters such as number of components, failure rates and operating time of the components. A particular case of Weibull failure laws i.e. Rayleigh laws is considered to examine the variation of MTSF and Reliability with respect to the parameters taken in the study. The behaviour of reliability and MTSF of the system comprising five subsystems each having five components have also been observed through graphs by considering different operating time and failure rates.

9 - 20 - illus,

019387   Chakraborty S;Sarma G C (Statistics Dep, Dibrugarh Univ, Dibrugarh-786 004, Email: subrata_dibru@rediffmail.com) : Doubly truncated extreme value distribution of type-I. Int J agric statist Sci 2017, 13(2), 379-86.

A doubly truncated extreme value distribution of type-I has been considered. Its cumulative distribution function, moments, quartiles, mode, generating functions and estimation of parameters by different methods have been investigated. Comparative evaluations of the benefits of truncation in data modeling have been carried out by fitting and testing six data sets.

6 tables, 15 ref

019386   Biradar B S;Santosha C D (Studied in Statistics Dep, Mysore Univ, Mysuru-570 006, Email: biradarbs1@gmail.com ) : Estimation of the mean of the exponential distribution using extreme ranked set sampling with unequal samples. Int J agric statist Sci 2017, 13(2), 393-401.

In many environmental studies, the main focus is on observational economy, that is to obtain data on the basis of cost effective and efficient sampling methods. In this paper, a ranked set sampling procedure with unequal samples based on extremes (ERSSU) is proposed, which reduces the cost and increases the precision of the estimator. Maximum likelihood estimator and modified maximum likelihood estimators are obtained and their properties are studied when the underlying distribution is exponential. These methods are studied under both perfect and imperfect ranking (with errors in ranking). These estimators are then compared with estimators based on simple random sampling (SRS) and ranked set sampling (RSS) procedures. It is shown that relative efficiencies of the estimators based on ERSSU are better than those of the estimator based on SRS. Simulation results show that efficiency of proposed estimator is better than estimators based on SRS and RSS, when errors in ranking are present.

8 tables, 16 ref

019385   Bhat M A;Maqbool S;Raja T A;Ganai N A (AGB Div, FVSc, SKUAST-Kashmir-190 006, Email: mabhat.1500@gmail.com) : Variance estimation using linear combination of gini's mean difference and deciles. Int J agric statist Sci 2017, 13(2), 527-30.

In this paper, authors have proposed a ratio type estimator for the estimation of population variance using linear combination of Gini's Mean Difference & Deciles. The expression of bias and mean square error of the proposed estimator has been derived up to first order approximation. The comparison between existing and proposed estimators has been carried out along with its efficiency conditions. The empirical study has been carried out by using two populations to assess the efficiency of proposed estimators over existing estimators.

5 tables, 6 ref

019384   Bajpayi A;Singh U;Singh R B;Patel L (Mathematics and Statistics Dep, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jablpur-482 004, Email: r_bahadursingh@yahoo.com) : Stochastic models for some time series production factors of mustard. Int J agric statist Sci 2017, 13(2), 595-600.

The aim of this study is to make a statistical analysis of the linear models in mustard production and productivity in Madhya Pradesh and India. The data set used for this analysis was taken from the Agriculture at a Glance, www.mpkrishi.org.in and Directorate of Economics and Statistics for 30 consecutive years (1985 to 2014). Following stochastic models were taken: Linear, Quadratic, Compound, - 19 - Cubic and Power. For model fitting performance, we used four comparison criteria; coefficient of determination (R²), sum of Squares error (SSE), root mean squares error (RMSE) and absolute prediction error (ARPE). The results indicated that cubic and quadratic models are more useful than other models to estimate mustard production and productivity in India and Madhya Pradesh.

1 illus, 4 tables, 4 ref

018453   Zoungrana P L (NO, Univ Ouaga II, 12, BP 412, Ouagadougou 12 Ouagadougou, Burkina Faso, Email: pati@univ-ouaga.bf) : Note on Lie-Yamaguti superalgebras. Far East J mathl Sci 2016, 100(1), 1-18.

A Lie-Yamaguti algebra (or general Lie triple system or Lie triple algebra) is a tangent algebraic system of the reductive homogeneous space studied by Nomizu in [3]. The class of Lie-Yamaguti algebras contains Malcev algebras and Lie triple systems as special classes. In this paper, we describe and give some properties of Lie-Yamaguti superalgebras. Also, we study a particular class of Lie-Yamaguti superalgebras.

8 ref

018452   Zainudin M L;Saaban A;Bakar M N A (School of Quantitative Sciences UUMCAS, Univ Utara Malaysia 06010 Sintok, Kedah, Malaysia, Email: mdlutfi07@gmail.com) : On comparison of estimation techniques for solar radiation missing data at Alor setar and Penang area in northern peninsular Malaysia. Far East J mathl Sci 2016, 100(2), 271-90.

The radiation data is important for solar data analysis which is significantly for modeling, designing on energy conversion system development and outputting it as a variable that is needed by other related scientific researches. Obtaining the complete data for solar intensity is a tough job when the technical problem is raised either from the sensor's devices or faulty data transmission. Next, missing values occur accordingly. As a solution, missing value estimation has been introduced to substitute the absent values with imputed values. This article is highlighted to propose cubic B‚zier interpolation as potential techniques to generate replacement values. Afterwards, compare the performance capability of few submitted interpolation techniques dealing with difference amount of simulated missing data. Based on our knowledge, curiosity works for replaceable values by applying B‚zier interpolation on solar radiation data is limited. The - 28 - cubic B‚zier interpolation performs very well on both areas but the most effective condition is at the lower missing values and higher absent values that come from Alor Setar and Penang cities, respectively, which offer the lowest RMSE value and the r² value nearest to 1.

4 illus, 3 tables, 20 ref

018451   Yoo J K (Liberal Arts and Science Dep, Chodang Univ, Muan 534-701, Korea) : Spectral mapping theorem for localizable spectrum. Far East J mathl Sci 2016, 100(3), 491-504.

Let T be a bounded linear operator on a complex Banach space X. Then the localizable spectrum σ_loc(T) of T is defined to be the set of all points λ ∈ C such that X^T(V) ≠ {0} for every open neighborhood V of λ. In this paper, we show that if T has SVEP, then σ_loc(f(T)) = f (σ_loc(T)) for a function f admissible in the analytic calculus. Also, we show that if Q ∈ L(X) is a quasi-nilpotent operator commuting with T ∈ L(X), then σ_T(x) = σ_T+Q(x) for all x ∈ X, and σ_loc(T) = σ_loc(T+Q). As a corollary, we show that if R ∈ (L(X) is a Riesz operator that commutes with T ∈ L(X), then σ_loc(π(T)) = σ_loc(π(T) + π(R)), where π : L(X) → L(X)/K(X) denotes the natural homomorphism. Finally, we show that if T ∈ L(X) and S ∈ L(Y), then σ_loc(T ⊕ S) = σ_loc(T) ∪ σ_loc(S).

16 ref

018450   Wong D C K;Ang M H (Mathematical and Actuarial Sciences Dep, Lee Kong Chian Faculty of Engineering and Science Universiti Tunku Abd, Bandar Sungai Long 43000, Kajang, Selangor, Malaysia, Email: deniswong@utar.edu.my ) : Results on building sets, extended building sets and double building sets. Far East J mathl Sci 2016, 100(4), 589-607.

9 ref

018449   Widodo B;Anggriani I;Khlimah D A;Zainal F D S;Imron C (Mathematics Dep, Faculty of Mathematics and Natural Sciences Institut Teknologi Sepuluh, Indonesia, Email: b_widodo@matematika.its.ac.id) : Unsteady boundary layer magnetohydrodynamics in micropolar fluid past a sphere. Far East J mathl Sci 2016, 100(2), 291-9.

Authors consider heat transfer unsteady boundary layer magnetohydrodynamics in micropolar fluid past a sphere. Dimensional governing equations formed from the physical problem by using the theory of the boundary layer. The dimensional governing equations consist of the continuity equation, momentum equation and energy equation. The dimensional governing equations are further converted into non-dimensional equations by introducing non-dimensional variables. The non-dimensional equations are further transformed into similarity equations and then solved numerically using the Keller-Box method. We obtain that the velocity profiles increase when both the values of magnetic variable, M, and micropolar parameter, K, increase. However, when we increase both these values, we obtain that the value of microrotation decreases.

6 illus, 5 ref

018448   Tangkanchanawong C (Mathematics Dep, Faculty of Science Khon Kaen Univ, Khon Kaen 40002, Thailand, Email: chitan@kku.ac.th) : Error estimation of occupancy urn model by Stein-Chen method via random graph. Far East J mathl Sci 2016, 100(2), 197-208.

In this paper, author gives an error estimation of the number of urns containing exactly k balls by Poisson distribution via Stein-Chen method.

17 ref

018447   Sutrima;Widyaningsih P (Mathematics Dep, Faculty of Mathematics and Natural Sciences, Sebelas Maret Univ, Surakarta, 57126, Indonesia, Email: sutrima@mipa.uns.ac.id) : Observability analysis of the pollution transport. Far East J mathl Sci 2016, 100(4), 549-60.

In this paper, observability analysis is performed for the transport of pollution in the river. The process is described by a parabolic partial differential equation. We report that the associated linear infinite-dimensional operator is a Riesz-spectral operator and generates a C₀-semigroup of bounded linear operators. Then we construct a sufficient and necessary condition for the approximate observability of the system. In particular, a finite number of dominant modes of the system are approximately observable when the input is measured at the output by an appropriate sensor. This result is confirmed by a numerical simulation.

1 illus, 1 table, 21 ref

018446   Susilowati L;Utoyo M I;Slamin (Mathematics Dep, Faculty of Sciences and Technology Airlangga Univ, Surabaya, Indonesia, Email: liliek-s@fst.unair.ac.id) : On commutative characterization of generalized comb and corona products of graphs with respect to the local metric dimension. Far East J mathl Sci 2016, 100(4), 643-60.

Let G be a connected graph with vertex set V(G) and W = {w₁, w₂, ..., w_m} ⊂ V(G). The representation of a vertex v ∈ V(G), with respect to W is the ordered m-tuple r(v|W) = (d(v, w₁), d(v, w₂), ..., d(v, w_m)), where d(v, w) represents the distance between vertices v and w. This set W - 26 - is called a local resolving set for G if every two adjacent vertices have a distinct representation anda minimum local resolving set is called a local basis of G. The cardinality of a local basis of G is called the local metric dimension of G, denoted by dim_l(G). In general, comb product and corona product are non-commutative operations in graphs. However, these operations can be made commutative with respect to local metric dimension for some graphs with certain conditions. In this paper, we determine the local metric dimension of generalized comb and corona products of graphs and obtain necessary and sufficient conditions of graphs in order that comb and corona products be commutative operations with respect to the local metric dimension.

9 ref

018445   Suriyakat W (Faculty of Science and Technology, Pibulsongkram Rajabhat Univ, Phitsanulok 65000, Thailand, Email: suriyakat@psru.ac.th) : Performance of exponentially weighted moving average control chart for exponential arima processes. Far East J mathl Sci 2016, 100(3), 371-84.

The exponentially weighted moving average (EWMA) control chart has widely used in applications to monitor and improve the quality of manufacturing and service systems. The in-control average run length (ARL₀) and out-of-control average run length (ARL₁) are the traditional measurements of the performance of control chart. In this paper, we study the EWMA control chart when observations are from autoregressive integrated moving average model (ARIMA(p, d, q)) with exponential white noise. The objective of this paper is to derive explicit formulas for the in-control average run length and out-of-control average run length on EWMA control chart. Numerical results obtained from explicit formulas and the numerical integration approach by using the Gauss-Legendre quadrature rule are presented. The results show that those approaches are in excellent agreement. However, the numerical results obtained from explicit formulas take computational times less than the results obtained from the numerical integration.

4 tables, 10 ref

018444   Sung Y O;Son B G (Applied Mathematics Dep, Kongju National Univ, 182 Sinkwandong Kongju-city, 314-701, Korea) : Notes of fuzzy congruences. Far East J mathl Sci 2016, 100(3), 385-96.

Authors carry on the investigation of fuzzy congruences on groups by introducing fuzzy difunctional relations and we show that there exists a one-to-one correspondence between FNS(G) and FC(G).

10 ref

018443   Sompong S;Rodjanadid B (Mathematics and Statistics Dep, Faculty of Science and Technology Sakon Nakhon Rajabhat Univ, Sakon Nakhon 47000, Thailand, Email: s_sanpinij@yahoo.com) : Neighborhood and accumulation points in bigeneralized topological spaces. Far East J mathl Sci 2016, 100(1), 65-79.

In this paper, authors introduce the notion of the neighborhood of a set and also accumulation points of a set in bigeneralized topological space and investigate their properties.

10 ref

018442   Seena V;Pilakkat R (Mathematics Dep, Calicut Univ, Malappuram-673 635, Email: seenavclt@gmail.com) : Hausdorff property of lexicographic, co-normal and homomorphic product of graphs. Far East J mathl Sci 2016, 100(2), 243-54.

A simple graph G is said to be Hausdorff if for any two distinct vertices u and v of G, one of the following conditions holds: (1) At least one of u and v is isolated. (2) There exist two - 25 - nonadjacent edges e₁ and e₂ of G such that e₁ is incident with u and e₂ is incident with v. In this paper, we derive sufficient conditions for lexicographic, co-normal and homomorphic product of two graphs to be Hausdorff.

7 illus, 10 ref

018441   Sangsura K;Poomsaard T (Mathematics Dep, Faculty of Science Mahasarakham Univ, Mahasarakham 44150, Thailand, Email: kittisak.s@msu.ac.th) : Graceful labelings of the classes of spider graphs with four legs of lengths greater than one S_n (k, l, m, 2). Far East J mathl Sci 2016, 100(2), 255-69.

A spider graph is a tree with at most one vertex of degree greater than 2. Let S_n(k, l, m, p) denote a spider of n legs (n ≥ 4) in which all of its legs have lengths one except four legs of lengths k, l, m and p (k ≥ 2, l ≥ 2, m ≥ 2, p ≥ 2). A graceful labeling of a tree T with n edges is a bijection f : V(T) → {0, 1, 2, ..., n} such that {| f(u) - f(v)| : {u, v} is an edge of T} = {1, 2, ..., n}. We prove that the classes of spider graph S_n(k, l, m, 2) are graceful.

6 illus, 8 ref

018440   Salah J (Basic Sciences Dep, College of Applied Sciences, A'Sharqiyah Univ, Ibra, Oman, Email: damous73@yahoo.com ) : Note on the modified Caputo's fractional calculus derivative operator. Far East J mathl Sci 2016, 100(4), 609-15.

In this paper, a connection between Caputo operator of fractional calculus and a modification of Caputo operator is provided. Furthermore, a special case of the modified Caputo operator is investigated by the means of its connection with some special functions.

7 ref

018439   Promsakon C (Mathematics Dep, Faculty of Applied Science. King Mongkut's Univ of Technology North Ba, Bangkok, 10800, Thailand) : Colorability of unitary addition cayley graphs. Far East J mathl Sci 2016, 100(2), 227-42.

Let n be a positive integer greater than 1, Z_n be the integer modulo n, and U_n be a set of all units in Z_n The unitary addition Cayley graph, denoted by G_n or Cay⁺ (Z_n, U_n is a graph whose vertex set is Z_n and two vertices uand vare adjacent if and only if u + v ∈ U_n. In this paper, we focus on coloring properties of unitary addition Cayley graph. We also find bounds of the chromatic numbers of G_n. Moreover, the sharpness of each bound is given.

3 illus, 16 ref

018438   Park J S (Mathematics Dep, Busan Univ of Foreign Studies 65, Geumsaem-ro 485 Beon-gil Geumjeong-gu, Busan 46234, Korea, Email: iohpark@pufs.ac.kr) : Surfaces embedded isometrically in the heisenberg group. Far East J mathl Sci 2016, 100(1), 117-33.

Let H be the 3-dimensional Heisenberg group and h be an arbitrarily given left invariant Riemannian metric on H. In this paper, minimal and flat surfaces (minimal and flat subgroups of H) embedded isometrically in (H, h) which are neither totally umblic nor totally geodesic are given.

8 ref

018437   Mecwan A I;Devashrayee N M (NO, , ) : Linearity analysis of traditional single and double balanced down conversion mixers. J VLSI Des Tool Technol 2016, 6(3), 22-7.

More sophisticated designs of communicating devices are required with tremendous scaling in MOS. Mixers play a vital role in all radio transmitters and receivers. To improve the sensitivity of the receivers, the low noise amplifiers are designed with very high gain. Higher gain of amplifier saturates the preceding sections and forces them to operate in the nonlinear region. MOS based Single Balanced and Double Balanced mixers are the most common designs for down conversion mixer. The paper discusses the linearity issue for both the traditional mixers. Basic definition of linearity is explained and the mathematical analysis based on Taylor's series expansion is carried out for single and double balanced mixers.

018436   Manna M Q;Jazmati M (Mathematics Dep, College of Science Al-Qassim Univ, P.O. Box 6644 Buraidah 51452, Saudi Arabia, Email: mohdqasim492@hotmail.com) : Topological inverse semigroup-groupoid and their covering. Far East J mathl Sci 2016, 100(1), 31-49.

In this paper, we introduce a definition to a topological inverse semigroup-groupoid and topological inverse subsemigroup-groupoid and discuss some of their properties. Further, we prove that the setof homotopy classes of paths in topological inverse semigroup isan inverse semigroup-groupoid. Also, we define the category TISGCov/X of topological inverse semigroup coverings of X and prove that its equivalent to the category ISGpGpdCov/π₁X covering groupoids of the inverse semigroup-groupoid π₁X. We also prove that the inverse semigroup structure of inverse semigroup-groupoid lifts to a universal covering groupoid.

8 ref

018435   Mahmood R M S (Mathematics Dep, Irbid National Univ, P.O. Box 2600, Code 21110 Irbid, Jordan, Email: rasheedmsm@yahoo.com) : On subgroups of finite index in quasi-free groups. Far East J mathl Sci 2016, 100(3), 439-50.

A group G is said to be a quasi-free group if G is a free product of a number of infinite cyclic groups and a certain number of cyclic groups of order 2. In this paper, we find the rank, structure, and a formula indicating the number of subgroups of finite index in a finitely generated quasi-free group.

10 ref

018434   Lekkoksung N;Jampachon P (Mathematics Dep, Faculty of Science Khon Kaen Univ, Khon Kaen 40002 Thailand, Email: n.lekkoksung@kkumail.com) : Some properties of generalized full - 23 - hypersubstitutions. Far East J mathl Sci 2016, 100(3), 343-59.

An algebra clone _GF(τ_n), of type τ_n is a couple of the set of all generalized full terms W_τn^GF(X) and generalized superposition Sⁿ. The generalized superposition is a tool to study generalized full hypersubstitutions. In this paper, authors study some properties of the clone_GF(τ_n and the generalized full hypersubstitutions. We show directly that the algebra Hyp^GF(τ_n):=(Hyp^GF (τ_n); °_GF, σ_id is a monoid. In fact, we do not use the subalgebra criterion to prove this fact which is given in [8].

8 ref

018433   Lasunon P (Faculty of Applied Science and Engineering, Khon Kaen Univ, Nong Khai Campus, Nong Khai 43000, Thailand, Email: lpatar@hotmail.com) : Scilab software package for the fuzzy analytical method (FAM). Far East J mathl Sci 2016, 100(2), 209-25.

In this paper, a new analytical method for calculating overall assessment results and the software package related to it are presented. The fuzzy set theory has been employed in the purposive analytical method that is called the fuzzy analytical method (FAM). The FAM is used to combine the assessment results from multi-criteria into an overall index. That index number can indicate the level of the overall assessment results more efficiently, more reliably and more rationally. The numerical examples show that the FAM can be put into practical use and can be more effective than making calculations by using a weighted average. The FAM algorithm has been developed with the Scilab programming language. This Scilab software package allows the overall index to be calculated with greater accuracy and convenience, and furthermore, the results are accomplished more quickly than with manual calculations. Therefore, for analytical optimization users, the FAM and its software package are interesting and useful, and they can be utilized to find the conditions that best fit their objectives.

5 illus, 6 tables, 12 ref

018432   Kim C B (Mathematics Dep, Kookmin Univ, Seoul, 136-702, Korea, Email: cbkim@kookmin.ac.kr) : On BR-algebras. Far East J mathl Sci 2016, 100(3), 451-62.

In this paper, authors introduce the notion of BR-algebras, which is a generalization of Coxetr algebras. Authors also investigate some relations between BR-algebra and the other algebras, i.e., BH-algebras, BF-algebras, BG-algebras, Coxeter algebras, and pre-coxeter algebras.

10 ref

018431   Khumprapussorn T (Mathematics Dep, Faculty of Science King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand, Email: thawatchai.kh@kmitl.ac.th) : On the (m, n)-jointly prime radical (R, S)-submodules. Far East J mathl Sci 2016, 100(1), 99-116.

In this paper, author presents and discusses the notion of (m, n)-jointly prime (R, S)-submodules as a generalization of jointly prime (R, S)-submodules.

2 ref

018430   Jitpattanakul A (Mathematics Dep, Faculty of Applied Science King Mongkut's Univ of Technology North Ban, Thailand, Email: anuchit.j@sci.kmutnb.ac.th) : Closure properties of - 22 - languages recognized by strictly k-edge finite state automata. Far East J mathl Sci 2016, 100(3), 397-411.

We study the model of computation called strictly k-edge finite state automata (S_k-FSA). This mathematical model has been introduced to compute naturally ordered data, which are transformed by other domains such as data in music processing. In order to use such model in practice, closure properties need to be investigated. We show here that the class of languages recognized S_k-FSA, called strictly k-acceptable languages (S_k-ACC), is closed under theoretic-set operations: union, intersection, complement and difference. Furthermore, we study its closure under two operators in language domain. It is shown that the class of S_k-ACC is closed under concatenation and Kleene-star operation.

11 ref

018429   Jampachon P;Poomsaard T (Mathematics Dep, Faculty of Science Khon Kaen Univ, Khon Kaen 40002, Thailand, Email: prajam@kku.ac.th) : Graceful labeling of spider graphs with three legs of lengths greater than one. Far East J mathl Sci 2016, 100(1), 51-64.

A spider graph is a tree with at most one vertex of degree greater than 2. Let S_n(k, l, m) denote a spider of n legs (n ≥ 3) in which all of its legs have lengths one except three legs of lengths k, l and m (k ≥ 2, l ≥ 2, m ≥ 2). A graceful labeling of a tree T with n edges is a bijection f : V(T) → {0, 1, 2 ..., n} such that {| f(u) - f(v)|: {u, v} is an edge of T} = {1, 2, ..., n}. We show that all spider graphs S_n(k, l, m) admit graceful labeling.

5 illus, 7 ref

018428   Jaafar N A;Yatim Y M;Sankar D S (School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, Email: duraisamysankar@utb.edu.bn) : Influence of chemical reaction on the steady dispersion of solute in blood flow - a mathematical model. Far East J mathl Sci 2016, 100(4), 617-42.

The shear augmented dispersion of solute in blood flow through (i) circular pipe and (ii) channel between two parallel flat plates with the effect of chemical reaction is investigated, treating the blood as non-Newtonian Casson fluid model. Classical integration methods are used to derive the analytical solution to the flow quantities of solvent fluid. Mathematica programs are developed for numerically solving convective diffusion equation in the shear flow region and also to obtain data for plotting various graphs and tabular values. The expressions for normalized velocity of solvent, solute concentration in the plug flow and shear flow regions, flow rate of solute and effective axial diffusivity are obtained. It is found that the effective axial diffusivity and relative axial diffusivity decrease with the increase of the chemical reaction parameter. The aforesaid flow quantities are lower when the solute disperses in the presence of chemical reaction than in the absence of chemical reaction. The effective axial diffusivity and relative axial diffusivity of solute are higher when it disperses in blood flow through circular pipe than in blood flow through channel.

6 illus, 2 tables, 29 ref

018427   Ihsan M;Wafdan R;Hafnani;Halfiani V;Ramli M (Multimedia Research Group, Mathematics Dep, Syiah Kuala Univ, Banda Aceh, Indonesia, Email: ramlimarwan@gmail.com) : Enhancement of an algorithm for finding a hamiltonian cycle. Far East J mathl Sci 2016, 100(4), 573-87.

This paper describes a new algorithm to find a Hamiltonian cycle on Hamiltonian graph using the backtracking method. This algorithm is able to reduce the number of backtracking processes when finding a Hamiltonian cycle with backtracking only at certain vertices and removing each vertex that has been passed in the graph. A Hamiltonian cycle can be found by searching paths forming a Hamiltonian cycle and discarding edges that are not needed to reduce the search space. However, the complexity of algorithm is still exponential because it basically uses the backtracking method and the Hamiltonian cycle problem itself is NP-complete.

4 illus, 23 ref

018426   Hussain M T;Ramli R;Khalid R (School of Quantitative Sciences, Univ Utara Malaysia 06010 UUM Sintok, Kedah Malaysia, Email: mushtaqth78@gmail.com) : Hybrid integer data envelopment analysis based on an alternative approach of super slack based measure for measuring super efficiency and inefficiency of decision making units. Far East J mathl Sci 2016, 100(1), 147-70.

Conventional data envelopment analysis (DEA) models assume that all values of input and output variables are non-integers. However, in many situations of real life DEA application, some of the input and/or output variables are to be integers. The rounding process of the non-integer values to their nearest integers can cause inaccurate efficiency and performance measurement. Thus, it is important to develop a non-radial hybrid integer DEA model. Moreover, the projection of decision making units (DMUs) in the existing super efficiency slack based measure hybrid integer model may not be strongly Pareto-efficient. Thus, our hybrid integer DEA model is developed based on an alternative super efficiency slack based measure DEA model for ranking efficient and inefficient DMUs. The developed model can project efficient DMUs resulted from super efficiency strongly Pareto-efficient by identifying input excesses and output shortfalls of non-integer and integer slack variables. It then discriminates inefficient DMUs whose efficiency scores resulted from super efficiency slack based measure model equal to one. An application to measure the efficiency of 41 academic departments at National Cheng Kung University in Taiwan (NCKU) is used to test the applicability of developed models. The results showed that 51.20% of the departments (DMUs) were super efficiency. Moreover, the result also showed that most of the inefficient departments were caused by their input excesses of expenses and teaching space, and output shortfalls associating with publications and grants.

1 illus, 5 tables, 38 ref

018425   Hima Bindu V M L;Kishore G N V;Rao K P R (Mathematics Dep, K.L. Univ, Vaddeswaram, Guntur-522 502, Email: v.m.1.himabindu@gmail.com) : Suzuki type unique common coupled fixed point theorem for jungck type maps in partial metric spaces. Far East J mathl Sci 2016, 100(4), 521-36.

In this paper, authros obtain a Suzuki type unique common coupled fixed point theorem for Jungck type maps in partial metric spaces. Also, we give an example which supports our theorem.

24 ref

018424   Goo Y H (Mathematics Dep, Hanseo Univ, Seosan, Chungnam, 356-706 Republic of Korea, Email: yhgoo@hanseo.ac.kr) : Uniform lipschitz stability and asymptotic property of perturbed nonlinear systems. Far East J mathl Sci 2016, 100(1), 81-98.

In this paper, author shows that the solutions of perturbed differential system y' = f(t, y) + ∫_t0^t g(s, y(s), T₁y(s)) ds + h(t, y(t), T₂y(t)) have uniform Lipschitz stability and asymptotic property under certain conditions imposed on the perturbed part ∫_t0^t g(s, y(s), T₁y(s))ds, h(t, y(t), T₂y(t)), and on the fundamental matrix of the unperturbed system y' = f(t, y).

18 ref

018423   Goo Y H (Mathematics Dep, Hanseo Univ Seosan, Chungnam 356-706 Republic of Korea, Email: yhgoo@hanseo.ac.kr) : Perturbations of nonlinear differential systems. Far East J mathl Sci 2016, 100(2), 171-96.

In this paper, author shows that the solutions to the nonlinear perturbed differential system y' = f(t,y) + ∫^t_t0 g(s, y(s), T₁y(s))ds + h(t,y(t), T₂y(t)), have boundedness and asymptotic behavior by imposing conditions on the perturbed part ∫_t0^t g(s, y(s), T₁y(s))ds, h(t, y(t), T₂y(t)), and on the fundamental matrix of the unperturbed system y' = f(t, y) using the notion of h-stability.

22 ref

018422   Gokhale M Y;Fernandes I (Mathematics Dep, Maharashtra Institute of Technology, Pune, Email: mukundyg@yahoo.com) : Lattice boltzmann simulation of forced convection in non-newtonian fluid through low permeable porous media. Far East J mathl Sci 2016, 100(2), 315-32.

Numerical simulation is carried out to study forced convection in non-Newtonian fluids flowing through low permeable porous media like sandstones and sand. Simulation is carried out using lattice Boltzmann method for both shear-thinning and shear-thickening, by varying the power-law index from 0.5 to 1.5 in Carreau-Yasuda model. Parameters involved in lattice Boltzmann method and Carreau model are identified to achieve numerical convergence. Permeability and porosity are varied in the range of 10^-10 to 10^-6 and 0.1 to 0.7, respectively, to match actual geometrical properties of sandstone. Numerical technology is validated by establishing Darcy's law by plotting the graph between velocity and pressure gradient. Consequently, investigation is carried out to study the influence of material properties of porous media on flow properties such as velocity profiles, temperature profiles and Nusselt number.

5 illus, 3 tables, 18 ref

018421   Dumrongpokaphan T;Kananthai A (Mathematics Dep, Faculty of Science Chiang Mai Univ, Chiang Mai 50200, Thailand, Email: malamnka@gmail.com) : On the estimation of the hedging of the asset price involving the asian option. Far East J mathl Sci 2016, 100(4), 537-48.

In this paper, authors study the hedging, particularly, the delta-hedging, the gamma-hedging and the theta-hedging of the asset price involving the Asian option. Actually, we know that the Asian option has no closed form. So, in this paper, we can estimate such closed form solution from the partial differential equation involving such Asian option. We obtain the new result which is interesting and may be useful in the research area of financial mathematics.

6 ref

018420   Chotwattakawanit U;Ratanaprasert C (Mathematics Dep, Faculty of Science Silpakorn Univ, Nakhon Pathom, 73000, Thailand, Email: udom.chotwat@gmail.com) : Galois connection of algebraic relations and colored resets. Far East J mathl Sci 2016, 100(3), 427-37.

Let M be a finite algebra and M = (M; Θ) be a reset whose Pol(Θ) = Clo(M). In this paper, we study a Galois connection of M-colored resets and algebraic relations over M. Its application in case when there is a finite structure which dualise a constantive algebra is also presented.

2 illus, 7 ref

018419   Cho Y U (Mathematics Education Dep, College of Education Silla Univ, Pusan 617-736, Korea, Email: yucho@silla.ac.kr) : Alternative proofs of baer and p.p. conditions. Far East J mathl Sci 2016, 100(3), 469-75.

Noticing a slip in the proof of Armendariz's result [2], according to which a reduced ring R is p.p. (Baer) if and only if the polynomial ring R[x] is p.p. (Baer), we provide a modified proof. Besides this, we obtain an equivalent condition for ring to be p.p.

5 ref

018418   Cho Y U (Mathematics Dep, Silla Univ, Pusan 617-736 Korea, Email: yucho@silla.ac.kr) : Properties of semicentral idempotent near-rings. Far East J mathl Sci 2016, 100(3), 463-8.

In this paper, authors investigate some properties of semicentral idempotents, which are related to the left regularity, right regularity and zero symmetric reducibility. We deduce that every zero-symmetric near-ring with reversibility is left semicentral idempotent. Finally, we obtain some properties of semicentral idempotent near-rings.

6 ref

018417   Cho Y D;Lee J S;Im Y B (College of Dharma, Dongguk Univ, Seoul 04620, Korea, Email: joyd@dongguk.edu) : Morphism of sheaves generated by a family of functions on a basis. Far East J mathl Sci 2016, 100(4), 561-71.

Authors extend a family of functions (δ(U) : F(U) → G(U))_U∈B which is natural in B to a morphism of sheaves η : F → G, where F and G are sheaves on a topological space X and B is a basis for X which is closed under finite intersections. Besides, we construct a morphism of sheaves η_α : ∏_i∈I F_i → π_α^*F_α for each α ∈ I, where π_α is the natural projection from the product space ∏ X_i to X_α and F_i is a sheaf on X_i for each i ∈ I.

6 ref