Applied Mechanics and Materials Vol. 145

Abstract: This present research mainly use bio-reagent process to degradation of medium to high strength phenol. To developing high efficiency process, the hollow fiber series-member bioreactor by Bacillus suctilis to treatment of phenol wastewater. The dependence of phenol degradation rate on biomass was studied, in which reciprocal hollow fiber series-member bioreactor. The result indicate the Bacillus suctilis biomass can efficiency of phenol degradation the initial concentration from 500 mg/L to 0 mg/L in bio reactor 75 hrs, and degradation rate is 6.67 mg phenol/L hr.

Abstract: The present study investigates the effect of flow arrangement on heat transfer characteristics in two-phase microchannel heat exchangers (MCHEs) with gas heating. The microchannel heat exchangers are developed to utilize the exhaust heat from a high-temperature gas product of a methanol reformer (a part of a reformed methanol fuel cell). Co-and counter-current flow types of MCHE are tested. Working fluids in the hot and cold sides are helium and liquid methanol, respectively. For both single-phase flow regions, the experimental results indicate that the actual effectiveness of the counter-current MCHE is higher than that of the co-current MCHE. Both of the actual effectiveness of co-and counter-current MCHEs significantly increases with an increase of cold side mass flux. Moreover, the actual effectiveness for both types of MCHE is less relationship to the hot-side thermal power in single-phase zone. The highest actual effectiveness is about 0.6 and 0.72 for co-and counter-current MCHEs, respectively.

Abstract: Smartphones provide portability and convenience to users by means of personal information profiles. However, when the phones are lost or stolen, security threats may cause personal information to be exposed. To resolve these problems, the network operator must provide users with remote-locking or wiping-out functions so that malicious users cannot use the mobile devices. In this paper, we propose a smartphone remote lock and data wipe scheme using password-based message authentication. The proposed scheme provides users with a mechanism for verifying the integrity of command messages so that malicious users cannot attack the device by intentionally transmitting lock or wipe commands. In addition, we show that the system is designed to fit in the standard SMS PDU, and we test the performance in terms of memory usage, authentication time, and bandwidth usage by implementing it on Android smartphones.

Abstract: Cloud computing is a new service style with many significant advantages and becoming a trend in the world nowadays. Although cloud computing can provide many significant advantages, it also brings us new security problems which present strong barriers for individuals/enterprises to adapt into cloud computing. Including European Network and Information Security Agency (ENISA), many international organizations have issued their reports on the issue of cloud computing security. However, the identification of risks the cloud computing faces also mix with traditional security problems. In this paper, we aim at identifying the critical security issues which are cloud computing-designated. The results of our identification are divided into three categories, namely, policy and organizational, technical, and legal issues, which were adopted by ENISA. We also carefully analyzed the literature on cloud computing security to identify critical cloud computing-designated risk items for each category. Detailed explanations about how the risk items were identified as the critical cloud computing-designated ones are also given to show the adequacy of the proposed identifications. Most of the cloud computing-designated security issues pointed out in this paper is still open and can be taken into consideration for cloud computing service providers when designing a new cloud computing technique.

Abstract: As the development of network learning, video compression is important for both data transmission and storage, especially in a digit channel. In this paper, we present the return prediction search (RPS) algorithm for block motion estimation. The proposed algorithm exploits the temporal correlation and characteristic of returning origin to obtain one or two predictive motion vector and selects one motion vector, which presents better result, to be the initial search center. In addition, we utilize the center-biased block matching algorithms to refine the final motion vector. Moreover, we used adaptive threshold technique to reduce the computational complexity in motion estimation. Experimental results show that RPS algorithm combined with 4SS, BBGDS, and UCBDS effectively improves the performance in terms of mean-square error measure with less average searching points. On the other hand, accelerated RPS (ARPS) algorithm takes only 38% of the searching computations than 3SS algorithm, and the reconstruction image quality of the ARPS algorithm is superior to 3SS algorithm about 0.30dB in average overall test sequences. In addition, we create an asynchronous learning environment which provides students and instructors flexibility in learning and teaching activities. The purpose of this web site is to teach and display our researchable results. Therefore, we believe this web site is one of the keys to help the modern student achieve mastery of complex Motion Estimation.

Abstract: It has been proved through the extensive study of continuous Form/Fill/Seal packaging machine that the outlook and final quality of the formed bags are largely dependent on the accurate synchronisation of vertical and horizontal sealing subsystems. In this paper, we first investigate synchronisation problem existed in the sealing system of traditional continuous F/F/S packaging machine which is mainly due to the mechanical non-constant transmission system used in the current continuous F/F/S packaging machine. A new control scheme is then proposed to address this problem in which the driving of the horizontal and vertical sealing has been made into independent but connected subsystems and controlled by separate control modules. We discuss the mathematical model and physical design in which the mechanical transmission part is discarded therefore simplifies the whole design of the machine. The new control scheme has been testified in several industrial applications with excellent performance result.

Abstract: The notion of technology innovation is similar to the phenomena of natural evolution because a lot of concepts in technology innovation such as technology trajectory and path dependency was originated the ideas of evolutionary theory. However, existing studies just deal with conceptual relationship between technology evolution and biological evolution without quantitative, detailed analysis. Genetic algorithm is a good approach which can investigate the evolution of promising technology by defining the mutation and selection of technology. Thus, this research aims at proposing a new approach to applying the genetic algorithm to grasp the evolution path of technology. For this, first, the analogy between technology evolution and natural evolution is identified. Second, the morphology of a selected technology is defined by extracting the keyword information from patent documents which are collected from database of USTPO (United State Trade and Patent Office) through text mining. Third, genetic algorithm is applied to analyze the evolutionary pattern of technology and derive the configurations of promising technology with software, describing the cells, mutation and selection of technology.

Abstract: Data Mining means a process of nontrivial extraction of implicit, previously and potentially useful information from data in databases. Mining closed large itemsets is a further work of mining association rules, which aims to find the set of necessary subsets of large itemsets that could be representative of all large itemsets. In this paper, we design a hybrid approach, considering the character of data, to mine the closed large itemsets efficiently. Two features of market basket analysis are considered – the number of items is large; the number of associated items for each item is small. Combining the cut-point method and the hash concept, the new algorithm can find the closed large itemsets efficiently. The simulation results show that the new algorithm outperforms the FP-CLOSE algorithm in the execution time and the space of storage.

Abstract: After inspecting the pitch contours of tone 1 of Mandarin speech, we found that the pitch contour of tone 1 consists of upward and downward line segments, while it is supposed that the contour of tone 1 is flat. Our study also found that tone 1 tends to be recognized as other three tones if the recognition algorithm used is based on the tone contour slope or shape. According to our experiments, we conclude that the recognition rate of the tones would be improved if two stage tone recognition scheme is conducted. At the first stage, tone one is recognized out and then the other three tones are identified at the second stage. The fundamental frequencies of input Mandarin speech of tone 1 are first retrieved from the training data and then a threshold value relating to standard deviation of fundamental frequencies is determined. In the first recognition stage, if the statistic standard deviation of fundamental frequencies is less than the determined threshold, the Mandarin speech is recognized as tone one. The input Mandarin speech which is not classified as tone 1 are the recognition targets of the second recognition stage. In the second stage, a so-called linear gradient analysis is conducted, and the tones are identified according to the derived positive or negative linear gradients. Our proposed recognition method is superior to traditional methods of Mandarin tone recognition in terms of effectiveness and recognition rate. Some experiments to prove the necessity of conducting two recognition stages will be described in detail.

Abstract: In the previous study, the dye decolorization was investigated by Tsukamurella sp. J8025 under the static condition at 30°C. The object of this study was to evaluate the influence of light irradiation with 15W low-pressure mercury lamp on dye decolorization. Three kinds of common culture medium Luria-Bertani (LB), Tryptic Soy Broth (TSB), and Yeast extract-Malt Extract (YEME) were used in this study. Strain J8025 was cultivated in different media added with methyl orange, and the rate of color removal was determined by measuring the absorbance at specific wavelengths. The experiments proved the decolorization efficiency after 48h under light irradiation in LB medium was up to 40%, that in TSB medium was up to 50%, and that in YEME medium was up to 68%, respectively. The decolorization process needed glucose as an energy source to support the bacterial growth and promote the decolorization rate. Due to the salt contained in the dye-wastewater, the effect of salt was investigated. The results showed nearly 98% color was removed after 48 h in the presence of 1% NaCl under light irradiation, but the decolorization was inhibited by high concentrations of salt. The results indicated a strain J8025 coupling with the light irradiation could be potentially used to improve the dye decolorization.