Precision Of The Refractometric Methods Of Moisture Honey Analysis [precisão Dos Métodos Refratométricos Para Análise De Umidade Em Mel]

For the determination of the moisture contents of honey, the Brazilian legislation adopts the refractometric method proposed by AOAC. However, in other work, the authors observed that the crystallization interferes in the refractive index measurement when the honey sample if encountered crystallized and, therefore, moisture contents overestimated were obtained. The European Honey Commission (EHC), adopt other refractometric method that use a pre-treatment of sample when this one was crystallized. So, the objective of this work was to compare the precision of these refractometric methods by different statistical techniques and it establish thus the more adequate procedure for moisture analysis in honey. The results of t-tests analysis in the 95% confidence level for the average moisture contents of the honey samples suggested that there were significant differences between the two-refractometric methods (AOAC e EHC) only for the crystallized samples. The analysis of standard deviations by application of F-test and building of confidence intervals shown that the EHC method was more precise than the AOAC methodology for the crystallized honey samples. In this way, it may be suggested the adoption by Brazilian legislation of refractometric method of EHC, as official method, by this one not present systematic errors.272328332Official Methods of Analysis of AOAC International (2000) 17th, 2. , ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTSBOGDANOV, S.MARTIN, P.LULLMAN, C. Harmonised Methods of the European Honey Commission. Apidologie, sp. iss., p. 1-59, 1997. 2a ed. Campinas. SP. Editora Unicamp. 2002BARROS NETO, B., SCARMINO, I.S., BRUNS, R.E., Como fazer experimentos: Pesquisa e desenvolvimento na ciência e na, , indústriaBOGDANOV, S., RUOFF, K., PERSANO ODDO, L., Physicochemical methods for characterization of unifloral honeys: A review (2004) Apidologie, 35, pp. S4-S17BRASIL. Instrução Normativa n. 11, de 20 de outubro de 2000. Regulamento Técnico de Identidade e Qualidade de Mel. Diário Oficial da União, Brasília, DF, 23 out 2000. Seção 1, n. 204, 23 pCANO, C.B., FELSNER, M.L., MATOS, J.R., BRUNS, R.E., WHATANABE, H.M., ALMEIDA-MURADIAN, L.B., Comparison of methods of determining moisture content of citrus and eucalyptus brazilian honeys by refractometry (2001) J. Food Comp. Anal, 14 (2), pp. 101-109CODEX ALIMENTARIUS STANDARD FOR HONEY. Ref. Nr. CL 1993/14-SH FAO e WHO, Roma, 1993ISENGARD, H., Water, D., Content, one of most important properties of food (2001) Food Control, 12, pp. 395-400MILLER, J.C., MILLER, J.N., (1993) Estadística para Química Analítica, , 2a. Ed. Delaware: Addison-Wesley Iberoamerican, S. ASTATSOFT INC, Statistica for Windows, Version 6.0, 2300 East 14 th Street, Tulsa, OK, 74104, USA, 1998VLACHOS, N.A., KARAPANTSIOS, T.D., Water content measurement of thin sheet starch products using a conductance technique (2000) J. Food Eng, 46, pp. 91-98WERNIMONT, G., Use of, T., (1985) Statistics to Develop and Evaluate Analytical Methods, , 1a. ed. Virginia: AOAC InternationalBERTHEA, R.M., DURAN, B.S., BOULLION, T.L., Statistical Methods for Engineers and Scientists (1985) Nova Iorque, , 2a. ed, Marcel DekkerMONTGOMERY, D.C., (1984) Design and Analysis of Experiments, , 2a. ed. Londres: John Wiley & SonsNIELSEN, S.S., (1994) Introduction to the Chemical Analysis of Foods, , 1 a. ed. Boston: Jones and Bartlett PublishersPOMERANZ, Y., MELOAN, C.E., Food Analysis: Theory and Practice (1994) Nova Iorque, , 3 a. ed, Chapmann & Hal

A New Intersection Model and Improved Algorithms for Tolerance Graphs

Tolerance graphs model interval relations in such a way that intervals can tolerate a certain degree of overlap without being in conflict. This class of graphs, which generalizes in a natural way both interval and permutation graphs, has attracted many research efforts since their introduction in [M. C. Golumbic and C. L. Monma, Congr. Numer., 35 (1982), pp. 321–331], as it finds many important applications in constraint-based temporal reasoning, resource allocation, and scheduling problems, among others. In this article we propose the first non-trivial intersection model for general tolerance graphs, given by three-dimensional parallelepipeds, which extends the widely known intersection model of parallelograms in the plane that characterizes the class of bounded tolerance graphs. Apart from being important on its own, this new representation also enables us to improve the time complexity of three problems on tolerance graphs. Namely, we present optimal O(n log n) algorithms for computing a minimum coloring and a maximum clique and an O(n2) algorithm for computing a maximum weight independent set in a tolerance graph with n vertices, thus improving the best known running times O(n2) and O(n3) for these problems, respectively

Longest increasing subsequences in windows based on canonical antichain partition

Given a sequence π1π2... πn, a longest increasing subsequence (LIS) in a window π〈l, r〉 = πlπl+1... πr is a longest subsequence σ = πi1πi2... πiT such that l ≤ i1 < i2 < · · · < iT ≤ r and πi1 < πi2 < · · · < πiT. We consider the Lisw problem, which is to find the longest increasing subsequences in a sliding window of fixed-size w over a sequence. Formally, it is to find a LIS for every window in a set SFIX = � π〈i + 1, i + w 〉 � � 0 ≤ i ≤ n − w � ∪ � π〈1, i〉, π〈n − i, n 〉 � � i < w �. By maintaining a canonical antichain partition in windows, we present an optimal output-sensitive algorithm to solve this problem in O(output) time, where output is the sum of the lengths of the n+w −1 LISs in those windows of SFIX. In addition, we propose a more generalized problem called Lisset problem, which is to find a LIS for every window in a set SVAR containing variable-size windows. By applying our algorithm, we provide an efficient solution for the Lisset problem to output a LIS (or all the LISs) in every window which is better than the straightforward generalization of classical LIS algorithms. An upper bound of our algorithm on the Lisset problem is discussed

New results for the 2-interval pattern problem

We present new results concerning the problem of nding a constrained pattern in a set of 2-intervals. Given a set of n 2-intervals D and a model R describing if two disjoint 2-intervals can be in precedence order (<), be allowed to nest (@) and/or be allowed to cross (G), the problem asks to nd a maximum cardinality subset D ′ ⊆ D such that any two 2-intervals in D ′ agree with R. We improve the time complexity of the best known algorithm for R = {@} by giving an optimal O(n log n) time algorithm. Also, we give a graph-like relaxation for R