Applied Mechanics and Materials Vol. 145

Abstract: Due to the product complexity and time constraint, it is common to conduct a collaborative design process to consider design requirements concurrently from the product lifecycle. However, such multi-disciplinary integration process may lead to potential design conflicts which has to be further resolved as the development continues. In this research, we propose a novel analytic model by combining the concepts of Ideal Final Result (IFR) and Trends analysis in TRIZ theory to systematically find the possible design contradictions from a top-down approach. The IFR is used to represent the integration of the developing product requirements which are requested from the collaborative team members. We then apply Trends analysis to compare the current state of existing product and the IFR state of the developing product. Therefore after comparison we will transform the differences into 39 engineering parameters defined in TRIZ to acquire possible design contradictions among components. The contributions of this methodology not only derive design conflicts systematically, but also help designers jump out of their psychological inertia and perform the design process with IFR to achieve distinct innovation.

Abstract: The smart grid is a network of computers and power infrastructures that monitor and manage energy usage and uses intelligent transmission and distribution networks to deliver electricity for improving the electric system’s reliability and efficiency. With grid controls, energy transmission management could be enhanced and resilience to control-system failures would be increased. Processing chips and storage units have been embedded into traditional electricity meters, so that they are capable of performing smart functions, called smart meters. Then, smart meters communicate with electrical appliances at home as well as the generation and management facilities at the power companies. Although deploying the smart grid has numerous social and technical benefits, several security and privacy concerns arise. Attackers might compromise smart meters, eavesdrop the communication, or hack into the power company’s database, to access power consumption data of the victim, from which they learn about the victim’s daily activities. Recently, various security and privacy vulnerabilities and threats have been studied in the research literature, however, most of the problems remain yet to be addressed. Therefore, it is crucial to design secure smart grid communication protocols that could prevent all possible security vulnerabilities. In this paper, we propose an anonymous authentication protocol for securing communication among various smart meters of the smart grid. The proposed protocol can achieve key agreement between smart meters and fully protect user privacy with low computation overhead. In addition, the analysis shows that the proposed protocol can satisfy the desirable security requirements and resist several notorious attacks.

Abstract: The purpose of this study is to integrate pathfinder and item response theory so as to manage concept structures. Concept structure is one important issue of knowledge management as to human knowledge storage. Pathfinder and item response theory are based on graph theory and psychometrics respectively and this integrated method should be feasible to represent concept structures. Besides, fuzzy clustering technique is adopted to provide features of concept structures based on homogeneity of sample. In this study, the empirical data is the assessment of linear algebra for university students. The important concepts of linear algebra consist of subspace, spanning, linear independent, R² and R³ and many literatures indicate concept structures of linear algebra will influence advanced mathematics. However, little is known about the concept structure and cognition diagnosis on linear algebra. In this study, it shows that lack of concrete examples in general dimensional space will prevent the development of the general theory. There are some limitations for students to use some materials to clarify complicated mathematic concepts perfectly. Most students could not be able to use the geometric insight and apply the Pythagorean of R² or R³. It shows that methodology of the pathfinder and item response theory will reveal important information of concept structures for students. In addition, fuzzy clustering could distinguish characteristics of concept structures on linear algebra. Finally, some limitations and suggestions as to this study are discussed.

Abstract: This paper reports the experimental of human walking style data collection system to know abnormal walking styles. The collection system is composed of 3D accelerator and body area network. Data is stored in a PC for the comparison of the normal and abnormal walking style differences. Based on the differences, we are going to define abnormal walking style in terms of 3D acceleration amplitudes.

Abstract: It is difficult to evaluate R&D performance especially for companies’ R&D in various industries because each industry has different characteristics and specific industrial environments. R&D performance evaluation can be measured by its quantitative output and firms’ performance. In this paper, R&D performance evaluation for each industry is analyzed by the indices of quantitative output and outcome, and the differences among industries can be checked for the indices. That is, one index can stand out in an industry, but another one can be remarkable in other industries. Whether the differences for each index among industries exist can be checked. We surveyed four industries such as machinery, electronics, parts & materials and IT by scoring index method with weight factors. The survey was conducted for small & medium-sized enterprises (SMEs) in Korea focused on R&D performance evaluation indices classified by output and outcome result which are gained from several hundred firms. More sensitive indices are specified for each industry, and the indices can be used with higher priority for evaluating firm’s R&D performance. By further research of the differences for each industry, the weight for indices can be specified in each industry, and the evaluation among heterogeneous industries can be performed by normalizing indices.

Abstract: With modern society entering an aging society, revitalizing elderly people's social activities and thus increasing their fall injuries leading to the fracture of various parts of the body, this study sought to examine shock amount generated when elderly people fall in diverse directions and hit the ground in a bid to develop a system aimed at minimizing shocks and preventing bone fractures. Existing studies dealt with young subjects sustaining fall injuries because a more number of elderly people suffer them, compared with young people, making it hard to obtain fall injuries data of elderly people. Thus, in this study, a system enabling a rapid movement and fall induction was used so as to simulate forced falls, and various joint movements during falls were measured using a 3-D human body movement analysis system. Young subjects participated in actual forced fall experiments, due to their safety, and their body movement data were input onto the human body movement simulation program so as to simulate falls, and resulting shock amounts were measured. Dynamic elements occurring during falls in various parts of the body, such as displacement, speed and acceleration, were input into the various parts of the body of elderly people models which were incorporated into the simulation program, and falls were simulated so as to calculate shock amounts generated when elderly people fall and hit the ground. Also, herein proposed was a system designed to reduce fall shock amounts with the aim of preventing bone fractures, using carbon dioxide gas, solenoid valves, air bag systems. This shock reduction system is believed to be used in the bone fracture prevention system that we are keeping researching on.

Abstract: Normal walking on staircases is a very important ordinary activity. It is a complicated motion that requires a big muscular strength and moment, and a big joint exercise scope. Due to such characteristics, staircase walking may be an obstacle to those with weakened lower limb muscle strength, and actually, fall injury accidents occur. Existing studies focus on dynamic changes in staircase walking. However, this study aimed to analyze staircase-walking characteristics evidenced when applying vibratory somatosensory stimulus to the ankle joint in a bid to reduce the risk of fall injuries associated with staircase walking. Five elderly male subjects, who had no disease related to the musculoskeletal system, participated in experiments. Experiments were held in a motion analysis laboratory equipped with 3-D motion analysis systems, force platforms, etc. In order to gather motion data, subjects wore markers and vibratory stimulation devices designed to apply somatosensory stimulus to ankle joints, and climbed down a staircase with the height adjusted appropriately. Using motion data gathered from staircase-walking, the ankle joint, knee joint and hip joint angles were obtained, and thus each joint's contribution to the motion was calculated. In the case of vibratory somatosensory stimuli being applied to the Achilles's tendon, the ankle joint contributed more to the motion of climbing down a staircase than the knee joint and the hip joint did. On the other hand, in the case of vibratory somatosensory stimulus being applied to the anterior tibialis, the ankle joint contribution was lowered, and to make up for it, the knee joint and the hip joint contribution increased. This outcome revealed that the effect of the vibratory somatosensory stimulation applied to the ankle joint can appear in not only the ankle joint, but also in the whole lower limbs due to chain reaction.

Abstract: In order to accommodate the global climate change, the idea of constructing zero-carbon green buildings has become the main stream and highest standard in building design in many countries. Located in subtropical zone, Taiwan features hot and humid weather in summer. The high usage of air conditioning is the main challenge to design zero-carbon green buildings in Taiwan. However, the temperature in the middle and high mountain areas decreases as altitude increases and makes it possible to create a living environment without using air conditioning in the summer. This project analyzed weather data in the middle and high mountain areas of Taiwan. The degree hour method and weather research and forecast model were used to evaluate the demand of air conditioning in the summer based on outside air temperature. The results showed that the low air conditioning load areas are above 1000 m elevation. This project then simulated energy consumption of a two-floor building near the Sun Moon Lake, an area of low air conditioning load, to explore the feasibility of zero-carbon green buildings in Taiwan. Based on the life style of a four-member family, a simulation process was conducted to estimate energy consumption of various appliances and different life habits. This study showed that the energy consumption in the buildings can be reduced up to 70% by using three major design strategies. These strategies include selection of a low air conditioning load location, using high energy efficient appliances, and application of energy conserving habits. Followed by renewable energy evaluation, it is possible to put zero-carbon green building into practice in Taiwan.

Abstract: This research reviewed the relevant patents on supporting devices for batting training of baseball and classified supporting devices which were used in baseball batting training in order to comprehend the latest research progress nowadays. We hope the technical level in batting training of baseball will be promoted by providing this research for employees in the professional baseball industry for reference.

Abstract: This research reviewed the relevant patents on supporting devices for pitching training of baseball in order to comprehend the latest research progress of supplementary devices for pitching training of baseball nowadays. We hope the technical level in pitching training of baseball will be promoted by providing this research for employees in the professional baseball industry for reference.