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1
Content available remote 3-D Simulation of Double-Bar Plush Fabrics with Jacquard Patterns
EN
A realistic computerized simulation of double-bar plush fabrics can result in a time-saving development process with high quality. Based on basic analysis of jacquard principles, a fast 3-D simulation method of warp-knitted plush fabrics is proposed by using a geometry shader on GPU. Firstly, pile areas and non-pile areas are identified according to the jacquard design graphs and chain notations. According to the directions of observation and raised pile, two layered chips are formed in the geometry shader with an approach of multi-layered textures. To ensure that the simulated piles resemble the real ones, the directions of the piles are randomized with the Perlin noise method. One pile is generated along its length with numerous layers in the plush fabric model. Simulation results of piles on both the technical face and technical back are obtained via the model built above, which is confirmed with practicability and efficiency. This 3D simulation approach improves the visualization appearance of piles just as they are actually raised.
EN
Applications of Piezo jacquard and CAD technology in warp-knitting have provided traditional jacquard fabrics with the possibility of innovating the structure design. Research on innovative design and fabrication is conducted aiming at knitting jacquard vamp fabric with the double-colour pitting effect on a technical back. By utilising Piezoelectric jacquard’s performance of displacing both underlapping and overlapping, new structures are formed, such as mesh stitches, koper stitches and float structures. Based on threading with yarns in two colors, jacquard bars in split execution create a pattern with a double-colour effect. To realize a highly efficient design, the paper proposes a computer-aided jacquard design method covering technical parameters and jacquard pattern design modules. Additionally, to pursue convenience and efficiency, mathematic models are built in terms of an automatic borderline design, loop stitching inspection and structure database. The method of jacquard vamp fabric design with a double-color pitting effect has been proven practically by illustrating a vamp design example which meets the requirement of fashion and performance well.
PL
Projektowanie dzianin dwukolorowych z efektem pittingu jest możliwe przy użyciu komputerowego systemu projektowania opartego na specjalnej metodzie dziewiarskiej. Dzięki macierzy i modelowi matematycznemu system obejmuje wszystkie podstawowe parametry techniczne modułów projektowego i kontrolnego oraz modułu bazy danych struktur, które współpracują w celu sprawnego projektowania dzianiny. Na podstawie otrzymanych wyników badań stwierdzono, że wspomagana komputerowo metoda projektowania może być z powodzeniem stosowana w projektowaniu dzianin dwukolorowych z efektem pittingu.
3
Content available remote Flat Knitting Loop Deformation Simulation Based on Interlacing Point Model
EN
In order to create realistic loop primitives suitable for the faster CAD of the flat-knitted fabric, we have performed research on the model of the loop as well as the variation of the loop surface. This paper proposes an interlacing point-based model for the loop center curve, and uses the cubic Bezier curve to fit the central curve of the regular loop, elongated loop, transfer loop, and irregular deformed loop. In this way, a general model for the central curve of the deformed loop is obtained. The obtained model is then utilized to perform texture mapping, texture interpolation, and brightness processing, simulating a clearly structured and lifelike deformed loop. The computer program LOOP is developed by using the algorithm. The deformed loop is simulated with different yarns, and the deformed loop is applied to design of a cable stitch, demonstrating feasibility of the proposed algorithm. This paper provides a loop primitive simulation method characterized by lifelikeness, yarn material variability, and deformation flexibility, and facilitates the loop-based fast computer-aided design (CAD) of the knitted fabric.
EN
Based on studying the constitution of yarn system and the geometric modality of relevant yarns in the multi-axial warp-knitted structure, 3D solid models of the loop yarns, insertion yarns and chopped strand mat in modern multi-axial warp-knitted fabrics were built to reflect the geometric structures of the three items by using NURBS curves and the principle of curved surfaces. Besides, OpenGL was employed to explore the corresponding 3D computer simulation system under the condition of VC++.NET, which could simulate the geometric model of multi-axial warp-knitted fabric. Meanwhile, through the selection of the unit cell of the fabric, the unit cell model of modern multi-axial warp-knitted fabric with chopped strand mat was developed and the relation between geometric parameters and process variables was deduced. The theoretical fibre volume fraction formula of modern multi-axial warp-knitted fabric with chopped strand mat was obtained as well. Furthermore, by using different specifications of fabric as samples, theoretical and experimental values of the fibre volume fraction were compared. The results revealed that there was good agreement between the theoretical and experimental values, which proved that the model was scientific and practical.
PL
Na podstawie badań struktury systemu przędz i geometrycznej modalności odpowiednich przędz w wieloosiowej dzianej strukturze osnowowej opracowano modele brył 3D przędz pętli, przędz wprowadzanych i struktur z włókien odcinkowych we współczesnych wieloosiowych dzianinach osnowowych w celu zobrazowania ich geometrycznych struktur dzięki zastosowaniu krzywych NURBS i reguł dotyczących zakrzywionych powierzchni. Oprócz tego zastosowano program OpenGL dla zbadania systemu symulacji komputerowej 3D przy warunkach VC++.NET, co pozwala na symulację geometrycznego modelu wieloosiowych dzianin osnowowych. Jednocześnie dzięki selekcji komórki podstawowej dzianiny opracowano model takiej komórki podstawowej dla konfiguracji wcześniej opisanej. Określono również zależności pomiędzy parametrami geometrycznymi a zmiennymi procesowymi. Uzyskano teoretyczną objętość włókien, następnie korzystając ze specyfikacji różnego rodzaju próbek określono zależności pomiędzy teoretycznymi i eksperymentalnymi wartościami objętości poszczególnych frakcji włókien. Wyniki wykazały, że istnieje zgodność pomiędzy teoretycznymi i eksperymentalnymi wartościami, co oznacza, że opracowany model jest naukowo uzasadniony i możliwy do stosowania w praktyce.
EN
This article proposes a method for designing and simulating jacquard warp-knitted towel fabric. Artistic conception drawing was used in realising the CAD design function of jacquard warp-knitted towel fabric based on the fabric structure and knitting principle. This study applied NURBS curves and the surface principle to build a three-dimensional solid model of the terry loop. Then using microscope type measurement instruments, the terry loop forms of the fabric surface were analysed and models of different forms of terry loop on the fabric surface built. With visual C++ for development tools combined with OpenGL graphics libraries, a CAD design and simulation function of jacquard warp-knitted towel fabric were finally realized within the CAD system.
PL
W artykule zaproponowano metodę projektowania i symulacji żakardowej ręcznikowej dzianiny osnowowej. Artystyczną koncepcję uwidocznioną na rysunku wykorzystano przy realizacji funkcji projektowania CAD w oparciu o strukturę dzianiny i zasady dziania. W analizie wykorzystano krzywe NURBS i charakterystykę powierzchni dla konstrukcji trójwymiarowych brył modelu pętli frotte. Następnie za pomocą pomiarów mikroskopowych analizowano pętle frotte utworzone na powierzchni dzianiny i stworzono modele różnych form tych pętli. Wykorzystując wizualizacje C++ w kombinacji z programem graficznym OpenGL zaprojektowano przy pomocy CAD wzory i symulacje funkcji żakardowej dzianiny osnowowej.
EN
Pure phase monoclinic bismuth vanadate powders of a nanosized diameter were synthesized by the hydrothermal method and characterized using XRD, TEM, DRS, Raman and FTIR techniques. The results revealed that the hydrothermal conditions (16 h at 140-240 °C) are favourable for the formation of monoclinic bismuth vanadate powders. They also indicated that if samples are prepared by the route described in this paper, an increase in the grain size and a gradual decrease of the band gap occur as the hydrothermal temperature increases.
7
Content available remote A Development of Inclusion-degree-based Rough Fuzzy Random Sets
EN
Given a widespread interest in rough sets as being applied to various tasks of data analysis, it is not surprising at all that we have witnessed a wave of further generalizations and algorithmic enhancements of this original concept. In this study, we investigate an idea of rough fuzzy random sets. This construct provides us with a certain generalization of rough sets by introducing the concept of inclusion degree. The underlying objective behind this development is to address the problems which involve co-existing factors of fuzziness and randomness thus giving rise to a notion of the fuzzy random approximation space based on inclusion degree. Some essential properties of rough approximation operators of such rough fuzzy random sets are discussed. Further theoretical foundations for the formation of rules constructed on a basis of available decision tables are offered as well.
EN
An HPLC method with a monolithic column and detection by mass spectrometry has been established for determination of chloramphenicol in honey samples previously cleaned by use of a modification of the QuEChERS procedure. Honey samples were dissolved in water containing sodium chloride and extracted with acetonitrile. Further sample clean-up was performed by simple reversed-solid-phase dispersion with primary–secondary amine (PSA) adsorbent. Chloramphenicol (CAP) residues at ppb concentrations were detected by liquid chromatography–mass spectrometry (LC–MS), with electrospray ionization, in negative-ion mode. The mobile phase was methanol–0.2% aqueous ammonium acetate solution, 45:55 (v/v). Under these conditions CAP is eluted after ∼4 min and 8 min from a Merck RP-18e monolithic column and a conventional C18 column, respectively. Recovery at three fortification levels (0.2, 20, and 200 µg kg.1) was in the range 78–93% with RSD from 3.7 to 3.9%. The coefficient of determination, R2, was 0.9995 over a 0.1–100 µg L.1 linear range. Use of this method for determination of CAP in honey resulted in an LCL of 0.20 µg kg.1. The method was validated on the basis of EU decision 2002/657. CCá and CCâ for the honey matrix were 0.002 and 0.006 µg kg.1, so the method was fit for the purpose of monitoring commercial products or checking MRL compliance.
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