Applied Mechanics and Materials Vol. 311

Abstract: This study delineates the design of an exploratory study which investigates the potential of using an interactive installation, Anikee, as unorthodox pedagogical tool to support children learning of the target language. The purpose of this study is to implement instructional gaming and adopt an inductive approach to investigate user perceptions engendered from interact Anikee as a language learning tool. The researchers’ working hypothesis is that interactive installation could serve as a virtual context rich in social interactions which could be conducive to the emergent development of communicative competence. Qualitative data will be collected from interviews and a post-interaction questionnaire and will be transcribed and analyzed. Analysis of interview and textual data focuses on how user-generated perceptions could be accounted for based on Hahha and Wozniak (2001) motivation theory. Coding schemes reflecting participants’ motivational trends in playing the interactive installation to learn English will be generated by multiple researchers to ensure inter-rater reliability. These user-generated perceptions could illuminate the strengths and weaknesses of utilizing digital media for media-assisted language learning and also inform motivations in playing to learn, digital play-based learning research, and future digital media design.

Abstract: Libraries have always played important roles in information provision services. In particular, university libraries have become a major source for teachers and students to acquire important information. University libraries use websites as the media for information dissemination and the tools for extended services, thereby ensuring more extensive and comprehensive circulation of information that transcends time and space. Library websites provide community services that users can make the most direct and active contacts with libraries through the community platforms. Library information, on the other hand, can enhance user interactions with librarians through the website community services. Targeting the 148 university library websites, a survey was conducted in this paper to understand how the libraries cope with the Internet era, and give a focus to and enhance the library website services and readers’ effectiveness of use. The survey also allows one to gain an insight into the current social network services; SNS provided by the university libraries. In addition to the weblog (blog), micro-blogging community services, such as Facebook, Twitter, and Plurk have also been added in recent years. Regardless of which community platform the library uses, it hopes to strengthen the exchanges of messages between readers, thus achieving more interactive library services and enabling the user and librarian to establish close community relationships.

Abstract: The purpose of this study is to use the software of MATLAB for processing the direct and reflected signals of GPS to monitor altitude of water surface in the water flume, as well as to establish a practicable technique of measuring sea water level. It is because before determining water wave pattern, the feasibility and accuracy of reflected GPS method must be proved. Therefore, there was a field test in the Mid-size wave flume of the Tainan Hydraulics Laboratory, National Cheng Kung University. After improving RGPS positioning procedure, the tranquil water level and the steadily descending of water level observation for one hour were performed. In this research, an integrated GPS receiver that employed direct and reflected GPS signals for the measurement was introduced. Both RHCP and LHCP antennas were employed to simultaneously receive the L1 and L2 carrier phase of direct and reflected signals. After the data analysis of the GPS observation, the position of signal reflection and the water level of the wave were solved. The results of the RGPS, wave gauge, and staff meter were coincided within 0.5cm ~ 1.0 cm. The differences between the reflection heights of this GPS system and the record of wave gauge were almost identical within 90%. It is proved the reflected GPS technique is possible to monitor water surface altitude and determine water wave patterns.

Abstract: A stock portfolio selection system based on a Grey Relational Analysis (GRA) model, a Fuzzy C-Means (FCM) clustering scheme and Rough Set (RS) theory is proposed. In the proposed approach, 53 financial indices are collected automatically for each stock item every quarter and a GRA model is used to consolidate these indices into six predetermined financial ratios (Grey Relational Grades (GRGs)). The GRGs of the stock items are then clustered using a FCM scheme and the resulting cluster indices are processed using RS theory to identify the lower approximate set within the stock system. The stock items within the lower approximate set are filtered in accordance with established investment principles and the six GRGs of each surviving stock item are then consolidated to a single GRG indicating the overall merit of the corresponding stock item in terms of its ability to maximize the rate of return on the investment portfolio. The validity of the proposed approach is demonstrated using electronic stock data extracted from the financial database maintained by the Taiwan Economic Journal (TEJ). It is shown that the rate of return on the investment portfolio selected using the proposed GRA/FCM/RS system is higher than the average rate of return predicted by the variation in the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) over the same period. Thus, the feasibility of the GRA-based attribute reduction mechanism and the overall viability of the proposed portfolio selection system are confirmed. Introduction

Abstract: The stock market is a well-developed and mature market. Nevertheless, it is not immune to international financial market changes, where volatility has reigned in recent years. Investors who misgauge stock trends can suffer dramatic losses. Accurate identification of market trends can still achieve outstanding performance and has become a major investor concern. This paper proposes a new stock price trend clustering model using a genetic algorithm to search for optimal investment strategies. Daily stock prices and trading volume data from the Taiwan stock exchange weighted index (TAIEX) was used to examine the proposed trend clustering model’s performance. The model was also compared to other popular stock market investment strategies to verify its validity. Research results confirmed that the trend clustering model correctly identified three different trends in the stock market. Furthermore, the trend investment strategy model using genetic algorithms performed better than other investment strategies, i.e. Granville’s rules for buy and hold strategies, in both bull and bear markets. Research results confirmed trend investing outperformed the other two investment strategies in return and capital distribution, both during the training period and the testing period.

Abstract: Energy-efficient routing is a very important issue in wireless sensor networks. An efficient routing method can avoid unnecessary data transmission and thus saves more power to extend the life of a network. The Connected Dominating Set (CDS) is a commonly used routing method which serves as a virtual backbone for a sensor network to achieve better transmission performance. The primary advantage of a CDS is its ability to adapt to the rapidly changed network topology. The construction of the CDS is a well-studied problem in an undirected unit disk graph, in which sensors are assumed to have the same transmission range. However, in practice, the sensors could have different transmission ranges due to their residual power or energy-saving mechanisms. The difference of transmission radius may form a one-way link between two nodes. Therefore, in this paper, we model the network as a directed graph and consider the CDS construction problem in such environment. We propose algorithms to construct a Strongly Connected Dominating Set (SCDS) which is a routing backbone that provides the service of efficient bidirectional data transmission between any two sensor nodes in the network.

Abstract: In this paper, an improved polytomous item relational structure theory based on Q-matrix theory is proposed, using Tatsuoka’s Q-matrix theory, we can construct the test with all efficient items which are fitting in with the given relational structure of cognitive attributes, and then, before the test, using Liu’s before-test item ordering theory, an ideal relational structural graph of itemscan be constructed, and the real efficient items can be obtained accordingly. After testing the students, an after-test structure of items can be estimated by using the Liu’s polytomous item relational structure theory. Furthermore, using Liu’s criterion related validity index, we can evaluate the estimated item relational structure of the test, and the results could be useful for cognitive diagnosis and remedial instruction.

Abstract: In this paper, we propose a novel method to generate pseudo-random-noise (PRN) bits for navigation applications. In the present method, the code sequence generator is constructed based on two chaotic logistic maps running parallel and starting from independent initial conditions. The logistic map is a simple mathematical model that shows bewildering complex behavior. By appro-priately setting the initial conditions, the PRN sequence is then generated by comparing the outputs of both logistic maps. Several simulations are set up to verify the correlation properties of the pseudo-random bit generator (PRBG). The result shows that the code sequences generated by the proposed PRBG have great auto- and cross-correlation properties, which are very similar to the PRN sequences used by GPS navigation system. The RPBG sequences are therefore suitable for signal ranging that is used comprehensively in the navigation system. On the other hand, the chaotic nature of the proposed PRBG codes can provide more secure communication than the traditional PRN sequences. The proposed PRN sequences are well suitable to be incorporated with the so-called chaotic shift keying (CSK) modulation.

Abstract: In this study, the nonlinear vibration model of structure with cross support is established. The conventional structure without cross support is linear and easy to be investigated. Unfortunately, its dynamic stability and vibration due to earthquake excitation are usually not acceptable. For suppressing the structural vibration the cross support composed of the elastic connecting bar and damper is considered here. This is a passive control design. Beside, due to the supporting arrangement, the mathematical model of the structure is highly nonlinear. In this study, the analytical solution for this system is derived. Further, the effects of control parameters on the vibration response are investigated.

Abstract: The fractal pattern is a highly visual aesthetic image. This article describes the generation method of Mandelbrot set to generate fractal art patterns. Based on the escape time algorithm on complex plane, the visual aesthetic fractal patterns are generated from Mandelbrot sets. The generated program development, a pictorial information system, is integrated through the application of Visual Basic programming language and development integration environment. Application of the development program, this article analyzes the shape of the fractal patterns generated by the different power orders of the Mandelbrot sets. Finally, the escape time algorithm has been proposed as the generation tools of highly visual aesthetic fractal patterns.