Sigma

Conservators frequently report that the removal of surface dirt and grime from acrylic paintings can be problematic. While increasing amounts of research is being published on the analysis of acrylic paints and the historical use of acrylic paints by artists, relatively little has focused on the characterisation of the effects of surface cleaning treatments. One of the current areas of research at Tate is the evaluation of surface cleaning treatments for acrylic paintings, which includes the characterisation of the physical and optical changes to acrylic paint films after cleaning. This forms part of a broad research collaboration on modern paints involving many academic and cultural institutions, such as the National Gallery of Art where researchers are developing chromatographic and spectroscopic methods for the identification of additives in acrylic paints and the characterisation of extractable components. The Getty Conservation Institute (GCI) is continuing to develop technique...

the main aim of this research project is to investigate the current lean modal exist in Electronic manufacturing small and medium firm. These projects mainly identify the success factor of the lean support to the cellular manufacturing in the medium and small electronic business set. The dissertation clearly illustrated the supportive lean model to the electronic manufacturing company that support to the capacity of high variety cellular manufacturing process

This paper presents an experimental investigation of the machining characteristics of AISI 304 austenitic stainless steel in turning process. During experiments, parameters such as cutting speed, feed rate and depth of cut were changed to explore their effect on the surface roughness, tool flank wear and tool – chip interface temperature. Chip forms were determined. Taking into consideration the experimental results, it is found that with increasing cutting speed, tool – chip interface temperature and tool flank wear were decreased. Surface roughness got better with decreasing feed rate and depth of cut.

Penelitian ini bertujuan untuk mengetahui ada tidaknya pengaruh motivasi orang tua terhadap prestasi belajar siswa pada bidang studi matematika di MTs Nahdlatun Nasyiin IV Pasanggar Pegantenan dan untuk mengetahui seberapa besar  pengaruh motivasi orang tua terhadap prestasi belajar siswa pada bidang studi matematika di MTs Nahdlatun Nasyiin IV Pasanggar Pegantenan. Penelitian ini merupakan jenis penelitian kuantitatif. Penelitian ini terdapat dua variabel yaitu variabel X (Motivasi orang tua) dan Y (prestasi belajar siswa). Populasi dalam penelitian ini yaitu semua siswa MTs Nahdlatun Nasyiin IV dimana diambil siswa kelas VIII yang berjumlah 21 siswa untuk dijadikan sampel . Teknik pengumpulan data yang digunakan adalah angket, wawancara dan dokumentasi. Teknik analisis yang digunakan adalah korelasi product moment .Berdasarkan hasil analisis data korelasi product moment diperoleh  r hitung = 0,930 sementara pada tabel  r product moment dengan N = 21 pada taraf signifikan 5% nilai ...

Penelitian ini bertujuan untuk mengidentifikasi kesalahan siswa serta faktor yang menjadi penyebab siswa melakukan kesalahan dalam menyelesaikan soal matematika pada materi trigonometri kelas X. Subjek penelitian ini adalah siswa kelas XI sebanyak 2 orang yang dipilih sesuai kriteria pada penelitian ini. Penelitian yang digunakan adalah penelitian deskriptif  kualitatif. Teknik yang digunakan untuk mengumpulkan data dalam penelitian ini adalah dengan melakukan tes dan wawancara. Dan kemudian, hasil tes dan wawancara di triangulasi dalam upaya mendapatkan data valid sehingga dapat dianalisis sebagai hasil dari penelitian ini. Adapun hasil penelitian menunjukkan bahwa jenis kesalahan dan faktor penyebab siswa dalam menyelesaikan soal matematika pada materi trigonometri di antaranya: Jenis Kesalahan meliputi kesalahan konsep, kesalahan prinsip, dan kesalahan operasi serta faktor penyebabnya yaitu dimana siswa kurang memahami soal dengan baik, kurang memahami tentang konsep yang terkait...

Genetic Algorithms are research algorithms which are based on natural selection and natural genetic mechanism. In this paper, the definition and the principle as operators of the genetic algorithms have been introduced and (crossover and mutation) have been analyzed. Various studies have been carried out for the engineering applications of genetic algorithms and information has been given about these studies. In the last part of this paper, An explanatory example related to genetic algorithms has been given.

We develop our method to prove quantum superintegrability of an integrable 2D system, based on recurrence relations obeyed by the eigenfunctions of the system with respect to separable coordinates. We show that the method provides rigorous proofs of superintegrability and explicit constructions of higher order generators for the symmetry algebra. We apply the method to 5 families of systems, each depending on a parameter $k$, including most notably the caged anisotropic oscillator, the Tremblay, Turbiner and Winternitz system and a deformed Kepler-Coulomb system, and we give proofs of quantum superintegrability for all rational values of $k$, new for 4 of these systems. In addition, we show that the explicit information supplied by the special function recurrence relations allows us to prove, for the first time in 4 cases, that the symmetry algebra generated by our lowest order symmetries closes and to determine the associated structure equations of the algebras for each $k$. We have no proof that our generating symmetries are of lowest possible order, but we have no counterexamples, and we are confident we can can always find any missing generators from our raising and lowering operator recurrences. We also get for free, one variable models of the action of the symmetry algebra in terms of difference operators. We describe how the St\"ackel transform acts and show that it preserves the structure equations.

The essay rereads some stylistic and structural elements of Petrolio, the great posthumous novel by Pier Paolo Pasolini. Referring to the most successful hermeneutic efforts on the text, the work emphasizes the role of contamination between media within the novel, as a key element to understand its singular form, drawing inspiration from Pasolini’s theoretical essays in Empirismo Eretico. In fact, it is precisely the field of the media and of intermediality where historically all the complex problems that Petrolio tried to address were emerging, in clear opposition with other outcomes of the contemporary postmodern literature.

Let h a positive integer, A a set of positive integers, with hA we denote the set of all integers representable as a sum of at most h elements of A (allowing repetitions). The Postage Stamp Problem, is to find the largest integer n = n(h,A) such that {1, . . . , n} hA.In this paper we present a new proof of the result of St¨ohr that say how to calculate n(h,A) when A has two elements. From this result we show that if h is a positive integer there exists a set A which is an extremal (, h)−basis and an extremal (, h+ 1)−basis for two stamps.In addition, we find the cases when exist a set which is an extremal (, h)−basis and an extremal (, h + 1)−basis in the case of three stamps.

The number of sleep spindles remains relatively stable within individuals from night to night. However, there is little explanation for the large interindividual differences in spindles. The authors investigated the relationship between spindles and intelligence quotient (IQ) in 3 separate studies. The number of spindles and sigma power were positively correlated with performance IQ (PIQ), but not verbal IQ (VIQ). The perceptual/analytical skills measured by the PIQ Picture Completion subscale accounted for most of the interindividual differences in spindles. Furthermore, there was a relationship between the rapid eye movements (REMs) of REM sleep and VIQ in individuals with higher IQ scores. A similar pattern was observed between spindles and PIQ. It was hypothesized that high-IQ individuals have more spindles that can support more complex cortical networks underlying perceptual/analytical abilities.

PENGGUNAAN LEMBAR AKTIVITAS SISWA PADA PEMBELAJARAN MATEMATIKA SMP DALAM MENINGKATKAN KEMANDIRIAN BELAJAR MAHASISWA Rika Sukmawati1, Yenni2,1,2Program Studi Pendidikan Matematika, Universitas Muhammadiyah TangerangEmail : rikasukma75rika@gmail.com Abstrak:Penelitian ini bertujuan untuk Mengetahui gambaran peningkatan kemandirian belajar  mahasiswa dalam penggunaan lembar aktivitas siswa (LAS) pada pembelajaran matematika Sekolah Menengah Pertama (SMP). Jenis penelitian yang dilakukan menggunakan metode penelitian kualitatif deskriptif. Subjek penelitiannya adalah mahasiswa semester 1 tahun akademik 2019/2020 Program Studi Pendidikan Matematika Fakultas Keguruan dan Ilmu Pendidikan Universitas Muhamadiyah Tangerang. Instrumen yang digunakan dalam penelitian ini menggunakan angket, lembar observasi, lembar Aktivitas Siswa dan pengamatan dokumen dengan pengolahan data menggunakan analisis persentase. Hasil penelitian menunjukkan kemandirian   mahasiswa meningkat berdasarkan indikator k...

En la parte inicial de este artículo se presenta una introducción al estudio de las curvas elípticas definidas sobre un campo K y algunas características de dichas curvas que dependen del campo sobre el cual se han definido; posteriormente se muestra que es posible definir una operación binaria entre los puntos de una curva elíptica proporcionándole a ésta estructura de grupo abeliano. En el apéndice se presentan algoritmos desarrollados en este trabajo, implementados en el sistema de álgebra computacional MuPAD.

The paper presents SIGMA (Semantic Government Mash-up Application), a platform able to create mash-ups by providing access to open governmental data. The proposed solution is based on the existing semantic Web technologies (especially RDF and SPARQL) and uses public distributed endpoints conforming to the Linked Data initiative. Also, SIGMA allows creating and deployment of independent plugins, encouraging the developers to build innovative applications, visualization solutions and mash-ups that give ...

Supercritical fluid extraction of grape seed oil was performed to study the effect of various parameters such as pressure (80–120 bar), temperature (40-50°C) and modifier concentration (10-30%) on the yield and composition of oil. Experiments were performed based on experimental design in three levels. The maximum yield of the oil was obtained by adding 30% of methanol as a modifier. The fatty acid composition of grape seed oil was analyzed by GC-MS using by a standard estimation method. Unsaturated fatty acids constitute about 70% of the oil, in conformance with respective literature.

Resumen: Gracias a la vision socio-antropologica de la sordera desde la decada de los 70's, la educacion se viene preocupando por replantear sus concepciones sobre lo que es la educacion especial y quienes deben ser parte de ella. La conclusion mas interesante es que la sordera no implica deficiencia mental. Esto ha hecho que todas las areas pertenecientes a la educacion se preocupen por pensar en la integracion y posteriormente en la inclusion de personas sordas en las aulas regulares de clase. Para el caso de la educacion matematica, los replanteamientos apenas tienen efectos importantes a partir de los ultimos anos, dejando grandes tareas para los educadores matematicos del presente y el futuro. En este articulo se realiza una aproximacion teorica sobre las ideas fundamentales para tener en cuenta al tratar con comunidad sorda, segun el informe de la investigacion Aprendizaje del concepto algebraico de variable y su relacion con las representaciones semioticas en una poblacio...

Present study deals with the various principles of Lean Construction where the concepts of POKA-YOKE, Visual Management, Just-In-Time, Total Quality Management, Employee Involvement, KAIZEN, KANBAN, 6S, Last Planner System (LPS), Value Stream Mapping are discussed along with their benefits and application in real field. In Lean construction the above-mentioned concepts and ideas play major role in success of many projects.

In this study, chlorine from 2-chlorophenol was removed with crude laccase enzyme produced from Trametes versicolor ATCC (200801) grown in PDB culture including wheat straw. Effects of pH value, substrate concentration, enzyme amount, contact time and temperature on dechlorination were examined. Besides, dissolved oxygen consumption was followed simultaneously dechlorination and the decrease was observed. A change in toxicity of 2-chlorophenol under determined optimum conditions was monitored through Microtox. ...

Penelitian ini merupakan penelitian deskriptif dengan menggunakan teknik the one shot case study yang bertujuan untuk mendeskripsikan aktivitas mahasiswa selama pembelajaran dan ketuntasan hasil belajar mahasiswa terhadap pembelajaran model Reciprocal Teaching. Tahap-tahap dalam Reciprocal Teaching yaitu 1) Qustioning Generating dimana mahasiswa diminta untuk membuat pertanyaan terkait materi yang sedang dibahas, 2) Clarifying mahasiswa diberi kesempatan untuk mengklarifikasi materi yang dianggap sulit yaitu dengan bertanya kepada guru, 3) Predicting mahasiswa diberi sola latihan yang memuat soal pengembangan yang harus dikerjakan secara individu, dan 4) Summarizing mahasiswa diminta untuk menyampaikan kesimpulan tentang materi yang dipelajari. pengumpulan data menggunakan metode observasi aktivitas mahasiswa dan tes. Data yang diperoleh, meliputi aktivitas mahasiswa dan ketuntasan hasil belajar mahasiswa terhadap pembelajaran Reciprocal Teaching.

The paper presents SIGMA (Semantic Government Mash-up Application), a platform able to create mash-ups by providing access to open governmental data. The proposed solution is based on the existing semantic Web technologies (especially RDF and SPARQL) and uses public distributed endpoints conforming to the Linked Data initiative. Also, SIGMA allows creating and deployment of independent plugins, encouraging the developers to build innovative applications, visualization solutions and mash-ups that give an improved access to the governmental data.

Abstract. The algebraic structure and the spectral properties of a special class of multicomponent NLS equations, related to the symmetric spaces of BD. I-type are analyzed. The focus of the study is on the spectral theory of the relevant Lax operators for different ...