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A case study of 2D non-separable wavelet bases for compression: Wavelets are the basic functions based on the filter banks. The 2-D separable filter banks are limited to capture the information of smooth contours in images. The 2-D non-separable filter banks with variety of directions will restrain that drawback [1]. The paper introduces the effective one-to-multi-dimensional transformations to build bidimensional filter banks for image/video compression. At the same time we make a comparison choose the best 2-D nonseparable filter banks.
A designed controller in the fuzzy sliding mode for robot control: The paper deals with the concepts of using fuzzy system as universal approximators for the robot nonlinear dynamic control systems. Here fuzzy system can be considered as switching function and its derivation as inputs that can be approximative to the robot nonlinear dynamics which is near to the switching hyperplane. It is simple for designing fuzzy controller and acquiring fuzzy rules. Finally, the result is obtained by the simulation. These results are accepted and the stability of controlled system is checked by Lyapunov method.
Adaptive control for a class of objects with delay: This paper presents a synthesis method for adaptive control systems for a class objects with delay. These objects are frequently met in the hydraulic installation, irrigation, transportation, in industrial aspects such as: chemical, biological and food processing technology, oil refine and processing technology, etc. Based on the adaptive control toll formed and a model of the Smith predictor and by the Lyapunov-Krasovsky functional method, control self-adjusted algorithms for dynamic systems with variable parametres and time-varying delay are synthesized. The self-adjusted algorithms are plain, technically realizable, that highly meet the requirement of quality of the system. The adaptive control system for the second-order objects is shown through an example. This method can be applied for a very large class of objects with delay, which usuallv are seen in practice.
Concentration of polychlorophenols, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in pulp, paper, waste water and sludge at some paper companies: Concentration of polychlorophenols (PCPs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) in pulp, paper, waste-water and sludge at some paper-companies has been determined by gas chromatography/ mass spectrometry (HP GC6890/ MSD5972A Hewlett Packard, USA). The relationship between ratio of concetration 2,3,7,8TCDD/ TEQpCDDs/PCDFS and 2,4,5-trichlorophenol/ PCPs has been observed. From the analysis results, contributed announcement about the resourse and main releasing procedures of dioxin at paper-compames was contributed.
Data transmission over multipath fading channels based on multicarrier modulation: Communication over ionospheric channel is typically available by multipath propagation. The recent advances ofDSP technology have provided parallel approach. We solve this problem by multicarier modulation. In this paper we described the system model, digital implementation and other problems to transmit data over multipath fading channels.
Effect of Gray codes on data areas around cross-points: This paper presents the effect of Gray codes on data area around cross points. Cross points which have binary codes corresponding to decimal codes of 2n may exist or not in real data, so at first the effect of Gray codes is determined with a contiguous data set, then this effect is generalized with real data without losing the generality for their statistical characteristics, espescially image or multimedia data. An another conclusion (a result of the determination above) is the change of data bits on areas around cross points for Gray codes from original data bits, this makes the probabilities of data bits and entropies of messages in those regions be changed, and this result has important effects on encode and decode process.
Fabrication of (1-X) silica- (X) titania films on monocrystalline silicon substrate and study on the effect of treatment temperature on their structure: (1-x) Silica- x Titania thin films with the ratios: 90/10, 85/15 and 80/20 on monocrystalline silicon substrate were prepared by using the sol-gel chemical synthesis process and spin-coating technique. The obtained thin films were heated from 150°C to 900°C for densification. The effect of the heating process on the structure change has been investigated by Thermo Analysis and infrared spectroscopy. The thin films with the thickness from 120 nm to 200 nm and refractive indexes from 1.49 to 1.60 were determined by ellipsometry method.
Hot pressing hard alloy based on WC-8%Co: The technical regime for hot pressing a hard alloy based on tungsten monocarbide with 8 mass % of cobalt is discovered. Grain growth during hot pressing of powder WC is minimized, probably as a result of the recrystallization in short time. It figused out that the tungsten content of hot pressed hard alloys in the cementing phase is lower than the one of those sintered in the ordinary way. Probably, it is related to the dependence of tungsten dissolution in the cementing phase of hard alloy on the time of tungsten monocarbide contacting with cobalt during sintering. The microstructure of hard WC-8%Co alloy obtained by hot pressing and ordinary sintering is studied, the pysico- mechanical characteristics and the composition of alloys in the cementing phase are determined as well.
Influence of test parameters when using accelerated weathering tests method to evaluate the quality of the organic coatings on the foundation of steel: In order to have suitable accelerated weathering test regime for material from steel with organic coatings used in different climate areas of Vietnam, we need to collect the climate data for many years, as well to understand the influence of each test parameter on the quality of test product. This study was carried out for solving this problem. With modern testing and measurement equipment, such as salt-spray chamber S 1 000 (Germane), UV chamber US-327-2 (American), Scanning Electron Microscopy JBM 5300 (Japan), electrochemical measurement equipment AUTO LAB (Holland), and with exact research methods based on testing standard such as ASTM B.117 (salt-spray testing), ASTM B 2237 (humidity - temperature testing), ASTM G-53 (radiation testing) and valuation of the property, the changes of 5 paint coating systems were made. From the research data it was proved that at the same duration of accelerated test the degradation speed of coating film in radiation testing increases in 1.3 - 1.5 times and 1.8 - 2.2 times compared with that in salt - spray testing and in humidity - temperature testing respectively.
On determination of structure for telecommunication management network: With respect to the state-space descriptive model for a Telecommunication Network (TN), the parameters of a relevant Telecommunication Management Network (TMN) are optimally obtained on adopting the state-optimization approach to the L2-norm problem for controllerreduction. On the basis of the constrained conditions (two matrix modified Lyapunov equations for model reduction, two matrix standard like-form Lyapunov ones for Standard Linear Quadratic Gaussian (LQG) Compensation) to be satisfied by the obtained parameters, two different structures for TMN node are proposed, depending upon the physical structure of each TN node under the consideration, self-wounding structure and sharing resource one. It is found that with the proposed structures, both TMN and TN are treated in a closed-loop configuration and that TMN is possible to filter out states highly contributing to the LQG-characteristic values of TN. That is, the performance of a TN will be improved remarkably by employing any of the proposed structures for TMN. In the paper, the solutions of 5 typical optimization-problems formulated relating with the service-roles of a TMN with respect to a given TN are firstly obtained by 21 references cited, leading to the conclusion from the dynamic point of view that the role of a TMN over the dynamics happening to be on a TN is exact the same as that of a reduced-order controller over a dynamic plant.
On determination of structure for telecommunication management network: With respect to the state-space descriptive model for a Telecommunication Network (TN), the parameters of a relevant Telecommunication Management Network (TMN) are optimally obtained on adopting the state-optimization approach to the L2-norm problem for controller reduction. On the basis of the constrained conditions (two matrix modified Lyapunov equations for model reduction, two matrix standard like-form Lyapunov ones for Standard Linear Quadratic Gaussian (LQG) Compensation) to be satisfied by the obtained parameters, two different structures for TMN node are proposed, depending upon the physical structure of each TN node under the consideration, self-wounding structure and sharing resource one. It is found that with the proposed structures, both TMN anh TN are treated in a closed-loop configuration and that TMN is possible to filter out states highly contributing to the LQG-characteristic values of TN. That is, the performance of a TN will be improved remarkably by employing any of the proposed structures for TMN. In the paper, the solutions of 5 typical optimization-problems formulated relating with the service-roles of a TMN with respect to a given TN are firstly obtained by 18 references cited, leading to the conclusion from the dynamic point of view that the roles of a TMN over the dynamics happening to be on a TN is exact the same as that of a reduced-order controller over a dynamic plant.
On stability problem of axially compressed bar as a system of in-out signals (MIMO-system): The paper presents a new approach to the elastic stability problem of axially compressed bar whith the conception of the control theory: - Simulate the object as the system with Multi - Input and Multi - Output (system MIMO) - To find the domain of observation of the single Output. - To find the domain of observation of the double Output. Numerical method with the software Matlab 6.0 in use is finite element method, determining the critical compressing force and gradient method which finds the size minimising the objective function.
Polycyclic aromatic hydrocarbon-degrading capacity of some bacterial strains isolated from the field trial of oil bioremediation treatment in Khe Che, Cua Luc, Quang Ninh: Field oil trial of bioremediation treatment for cleaning up contaminated intertidal sediment oil in Khe Che was carried out. Seven polycyclic aromatic hydrocarbon-degrading bacterial strains were isolated from sediment samples of this bioremediation treatment and titled as KCP2, KCP3, KCP7, KCP8, KCP9, KCPll and KCPI5. Among these strains, KCP3, KCP7 and KCP8 could show better ability of the degradation of polycyclic aromatic hydrocarbon (P AH). Based on the morphological and physiological characteristics as well as API 20NE tests, we proposed that two strains KCP3 and KCP7 should be placed by genera Pseudomomas and Sphingomonas respectively. Seven bacterial strains showed the different P AH degradative capacities After 7 days of cultivation on mineral medium containing mixture of P AHs as sole carbon and energy sources, KCP3, KCP7 and KCP8 have degraded 63.13%,69.08% and 76.12% respectively. In the mixture ofPAHs, strains KCP3, KCP7 and KCP8 have utilized at 65.13%,73.09 and 79.96% phenanthrene respectively, 46.33%, 49.97% and 71.09% anthracene respectively. These three strains have also degraded 59.06%, 46.23% and 41.01% fluoranthrene in the mixture of PAHs.
Principles for designing of planar cams using analytical mathematics and its application: The purpose of the research in cam synthesis is not only to find the optimal design methods but also to create the basic principles to study the formation theory of contact profiles in special gears. Cam dynamic synthesis can be carried out by the following two methods, analysis mathematics or vector graphs. However, the synthetic process has still faced with the problems that need further research, such as determining the laws of pressure angle and the optimal way to calaclate the roller's diameter. In this paper, the authors propose some calculating methods to satisfy all requirements of the design and manufacture of modem cams. A disk cam with a rotating roller is used as an illustrating example.
Research on treating and recycling water in coal flotation process engineering: The investigation on the complex dispersed sludge collected from the coal washery technology at Hon Gai Coal Washery Company was carried out and found that the distribution density of the dispersed solid particles concentrated mainly at the diameter of 10.2 mm. The gravitational settling ability of them was not acceptable in industrial range. By using flocculants based on polyacrylamid, the settling velocity of solid particles reached to 20 rnI4. The slurry gained after the settling process was dewatered by mean of filtration at the pressure of 0,025 MPa. The moisture content of the filter cake reached to 35%.
Researching on antiserum production technology and its application to sacbrood disease prevention and treatment for infected honeybee colonies: Sacbrood disease is perhaps the most common viral disease of honeybees. In Vietnam Sacbrood diseases have been recorded as Sacbrood disease of the common honeybee Apis mellifera and Sacbrood disease of the Asian hive bee A. cerana. It has caused great damage to honeybee colonies as well as honey products. Diseased larvae fail to pupate after four days, they remain stretched out on their backs within their cells. The anterior section of the larva, consisting of its head and thorax, is the first part of its body to change colour, passing from white to pale yellow and finally dark brown and black. Dead larvae remaining within their cells eventually dry out to flat scales that adhere to the cell floor. Although no chemotherapeutic agent is effective in preventing or controlling Sacbrood disease, colonies often recover from the infection without the beekeeper's intervention. The disease usually occurs when the colony is in a stress situation (shortage of food-storage space, unfavourable climatic conditions such as dampness during the rainy or cold season, unhygienic hive interior, poor queen, infestation with other diseases... To prevent and cure infected honeybee from Sacbrood disease caused by virus Sacbrood is a very important and essential task, not only for the farmers, but also for the researchers and scientists. In order to deal with this problem, it is assumed that the following tasks have to be done: isolating Sacbrood virus from infected samples, studying on its biological characteristics and manufacturing antiserum. Based on this, it is able to produce vacin in the near future. Strain Sacbrood H98 has been isolated and kept in low temperature condition (- 4°C) in Department of Immunology, Institute of Biotechnology. We have obtained the results such as EI50= 10-4.7, ELD50= 10-3,15, TCID50= 10-5.6. In this report we offered a method of manufacturing antiserum by rabbit body and use antiserum solution to prevent and cure infected honeybee colonies from Sacbrood disease with very high effectiveness (from 92,85% to 95,45%).
Shoot regeneration from callus and its application for the micropropagation of Anthurium Sp.: In this article, the protocol for the micropropagation of Anthurium sp. from leaf segments and seeds is presented. Plant regeneration and micropropagation of Anthurium "Sonate" by leaf segment culture can be carried out about 10 - 12 months that includes callus formation (2 months), callus proliferation (4 months), shoot regeneration (3 months) and root formation (2 months). The plantlets can flower within 12 months in greenhouse. Seeds were germinated on 1/2 MS medium supplemented with 1 mg/l IAA. Plants were obtained by seed culture which was very important for back-cross process. These methods can be used for the cropropagation of many Anthurium species of newly imported with great numbers and at a low price.
Solving method of typical problems for modeling of telecommunication metwork: The article "On a modeling method for telecommunication network: Formulation of typical problems" has been published in Vol. 42, No. I of this Journal, in which 4 typical problems for TN modeling in the state-space has been formulated. The first problem is stated for classical electronic switch, the second one is considered for a multi-delayed level buffer which happens to be with an electronic switch in an asynchronous transfer mode (ATM) switch. The following one is related with the interfacing dynamics for establishing an advanced electronic switch other than ATM one. The last one is formulated for a specified dynamics which plays the most important role in characterizing a soft-switch. This paper reports the obtained pseudo-linear models and the results for robustness of the said pseudo-linear model on adopting different methods from frequency domain to time one. The paper consists of 2 paragraphs excepting the first one is for introduction. In the second paragraph, the details of obtained results for the formulated problems are reported on adopting either the state-optimization approach, or the classical optimization method. It is worth while to mention that from different methods available in the literature for tackling the question of robustness for each quasilinear model is suitably selected, incorporating together all in a form for better understanding of non control, interested readers.Conclusion remarks and direction for further reseachs are in the last item of the paper.
Some results of research on improvement of alluvial soil by inorganic binding sustances for the foundation of waterlogged structures: Soil improvement by using inorganic binding substances (lime, fly ash, cement) has been researched and applied since along time world wide and in our country. The problem is whether other kinds of ashes can be used for this purpose in the areas where fly ash is lacking, and what improvement is needed for the soil used as foundation for the dikes in the coastal areas for aquaculture. In 2003 the author and a research group of the Phuong Dong University have improved the alluvial soil with the use of some other ashes such a rice shell ash, maize plant ash, sugar cane ash, and improved soil in the fresh water and sea water environment. The research has given encouraging results, opening a new perspective in preparation of improved soil for building dykes and embankment etc. in the coastal area. This will assist in the protection of the structures submerged by floodwater and seawater in the coastal areas of Viet Nam especially the areas in the MeKong River delta. The research on improvement of soil by using inorganic subtances for the foundations of submerged structures involves the research of many parameters. But the research project has been limited only to the investigation of the three parameters: relative density, compressive strength and water resistance. Other parameters will be investigated only when these three parameters are found to be satisfactory. Other parameters for implementation of the research project is still in the first stage. But, as the budget is limited, other parameters still cannot be investigated. The paper presents the results of the research and their evaluation.
Study on chemical constituents of pseuderanthemum palatiferum Nees Radlk: The leaves of Pseuderanthemum palatiferum (Nees) Radlk. (Acanthaceae) have been found to contain J3-sitosterol, phytol, 3-O-(J3-D-glucopyranosyl)-sitosterol, an epimeric mixture of stigmasterol and poriferasterol, n-pentacosan-l-01 and a mixture of kaempferol3-methyl ether 7O-J3-glucoside and apigenin 7-0-J3-glucoside [4, 5]. We herein further report on the isolation and structural elucidation of additional components: I-triacontanol (1), salicylic acid (4), glycerol 1hexadecanoate (2) and palmitic acid (3). Structures of these compounds have been elucidated by IR, MS, 1H-NMR and I3C-NMR spectroscopy. In Vietnam, the leaves of Pseuderanthemum palatiferum (Nees) Radlk. are used as a traditional medicine for treating inflammation and digestive troubles. First studies have shown that extracts from the leaves of this plant had antibacterial and antifungal activities.
Study on effects of technological parameters on cutting capacity and surface quality by 1000 W CO2-laser: Laser cutting technology is widey used for machining materials. Laser-cut kerts is strongly effected by various parameters, for instance resonator by power, cutting head velocity, stand-off distance, specifications of gases, pressure of blowing gases, nozzle structure and dimensions, etc. The investigation and study of the effects on laser cutting process is very important. It is just the fundamental for constructing a technological parameters optimizing program. Such software is of full use in scientific studies.
Study on the preparation of the blends based on PVC and dynamically vulcanized NBR, containing DOP: The preparation of the blends based on poly(vinyl chloride) (PVC) and dynamically vulcanized butadiene-acrylonitrile rubbber (NBR), containing dioctyl-phtalate (DOP) has been carried out. To obtain a suitable blending condition, the weight ratio PVC/NBR/DOP of the blends was fixed at 100/50/35. The blends were prepared in an intermixer model Haake Polylab in two steps. The first step: NBR, additives for NBR, part of PVC and additives for PVC were mixed for 7 min at 80°C and spreed of 20 rpm with the fill factor 0.7. The second step: The mixture obtained was then mixed with the remaining PVC amount and additives for PVC with the fill factor 0.7. Temperature, time and blending speed were varied from 120 to 170°C, 3 to 15 min and 20 to 50 rpm respectively. The dependence of processability and mechanical properties of the blends on the technological blending parameters: the amount of PVC in the first step, temperature, time and blending speed in the second step have been investigated. It might be drawn out that the amount of PVC in the first step and the blending temperature in the second step affect strongly both the processability and the mechanical properties of the blends. But the time and the blending speed affect only the mechanical properties of the blends. The results of morphological studies by SEM show clearly the relation between mechanical properties of the blends and the size of the rubber phase. According to the obtained results, the suitable condition to prepare blends based on PVC and dynamically vulcanized NBR, containing DOP was established as follows: In the first step: The amount of PVC added is 50 ppw. In the second step: Temperature, time and blending speed are 165°C, 7 min and 30 rpm respectively. At this blending condition, the blend exhibits the good processability, high tensile strength and high alongation at break (19.0 MPa, 360%).
The application of wavelet frames and bases of Hilbert space to multicarrier direct-sequence spread-spectrum systems: It is observed that communication systems can be considered mathematically consisting of different transforms, in which, a linear combination or a series of some predefined functions are very often used for expressing signals under consideration. However, orthogonal bases are commonly used for modern communication systems with some certain properties for practical purposes. This leads to the role playing by frames rather than that playing by bases. In this paper, a few mathematical background on wavelet transformation and wavelet frame is described first. Then a proposed model by adopting wavelet frame for multicarrier direct sequence spread-spectrum system is analyzed with respect to system's performance from both theoretical and experimental aspects. It is worthwhile to mention from the performance point of view that there is no improvement between the two systems, wavelet frame and Fourier based, under the consideration of the additive white Gaussian noise. However, for a fading channel the performance of wavelet frame based system is observably improved with respect to that of Fourier based one.
The composition and phase structures of Fe-Cr-C alloy in relation with abrasion and corrosion resistance for mine machinery: The main structures of Fe-Cr-C alloy consist of carbide grains and matrix phase, the last one may be pecht or martensite or austenite. The alloy with pecht matrix has minimum wear coefficient. Martensite or autenite has the best structure. The Chromium content Cr = 18 - 20% is satisfied for abrasion resistance, but for corrsion resistance it should be up to 30%.
To define sinking-displacement of the bottom of the pile which was driven into identical foundation: Based on the one-way wave theory and Dalambe solution, authors studied shock between the hammer and the pile with linear damper-mattress. The pile was driven into identical foundation and the bottom of the pile met constant prop-force. Author calculated sinking-speed expression of the pile bottom in one shock and combined with a MA TLAB computer programme to draw graph's sinking speed and on time begin, finish sinking of the pile bottom.
study on cultivation with casing soil technique of oyster-abalone mushroom pleurotus eryngii in Vietnam: A new technique of cultivation of Oyster mushroom Pleura/us eryngii has been developed applying a layer - 2 cm of casing soil upon the mixed substrates with rice straw and sawdust of rubber trees to enhance the growth and harvest yield of fruitbodies. In the latter case, the fruitbodies formed well with longer stipes swollen at the base.