Li-Chieh Chen

Knowledge-based support for simulation analysis of manufacturing cells

Abstract Simulation is a widely used approach for assisting design and improvement of manufacturing systems. It is a complex activity and needs a great deal of human expertise. Since the knowledge of analyzing simulation output for decision making is not inherently captured in the simulation modeling methodology, a framework that integrates simulation and knowledge-based decision analysis is needed. In this paper, we develop a knowledge-based system that cooperates with simulation for improving the performance of manufacturing cells. Using Axiomatic Design as a guideline, a hierarchical knowledge base structure that corresponds to the decision process is built. Our proposed knowledge-based system consists of a set of facts and three levels of rules in a hierarchy that is consistent with the manufacturing cell system configuration. The system demonstrates the effectiveness of utilizing Axiomatic Design concept when developing a knowledge-based system. The results of an industrial study show that our method contributes to improving the performance of manufacturing cells.

Developing the index for product design communication and evaluation from emotional perspectives

Often customers make their purchase decision based on price, quality and functionality of the product. Sometimes the decision is influenced by the perceived value, which is always subjective and emotion-driven. In order to ensure successful launch of a product, it is extremely important to predict the perceived value of design alternatives systematically based on the common language understood by both target users and designers. However, the index for communicating and evaluating such value from emotional perspective is not available in the literature. Therefore, the objective of this research is to extract key indexes of perceived value from emotional perspectives and develop an effective algorithm to evaluate products. First, through literature review and the interview of participants, many scenarios of purchase decision were collected. A focus group was invited to identify the essential elements that influence the perceived value of products. Followed by a large scale questionnaire survey and factor analysis, four indexes were extracted. These indexes, named as FASE Index in brief, included features, association, social-esteem, and engagement. Second, by combining the fuzzy mathematics and the pairwise comparison method, an evaluation model was developed. Third, the perception differences of sample products were conducted to verify the validity of FASE index. The findings of this study demonstrated that FASE index was effective for decision making in product design.

A Study on the Design of Augmented Reality User Interfaces for Mobile Learning Systems in Heritage Temples

In order to reduce switching attention and increase the performance and pleasure of mobile learning in heritage temples, the objective of this research was to employ the technology of Augmented Reality (AR) on the user interfaces of mobile devices. Based on field study and literature review, three user interface prototypes were constructed. They both offered two service modes but differed in the location of navigation bars and text display approaches. The results of experiment showed that users preferred animated and interactive virtual objects or characters with sound effects. In addition, transparent background of images and text message boxes were better. The superimposed information should not cover more than thirty percents of the screen so that users could still see the background clearly.

Surfing in the crowd: feasibility study of experience sharing in a Taiwanese night market

Social Proximity Applications (SPAs) have prompted a promising opportunity for mobile services that utilize the changes in daily life in the proximity of mobile users. This paper describes our research-in-progress about designing and developing a mobile SPA, which facilitates social interaction among visitors in a night market crowd. This application allows night market visitors to share their experiences in photos with nearby others via their Bluetooth-enabled mobile phones. The design was based on a two-week field observation in an attempt to investigate the motivations and attitudes towards applications of this type. After a three-night extensive trial we found the value of the application - privacy-sensitive, playful, and enjoyable, yields high consistency with results from field observation. The ultimate goal is to identify potential engaging design extensions to the current prototype.

Exploring the Ergonomic Issues of User-Defined Mid-Air Gestures for Interactive Product Exhibition

Recently, the applications of 3D and mid-air hand gestures have increased significantly in public and interactive display systems. Due to the context and user differences, it is necessary to consider user-defined gestures at the design stage of the system development. However, user-defined gestures may not be able to conform to the requirements of ergonomics without in-depth studies and careful selection. Therefore, the objective of this research is to develop a systematic method for extraction and evaluation of user-defined gestures from ergonomic perspectives. In this research, a behavior coding scheme was developed to analyze gestures for six tasks of interactive product exhibition. The results indicated that hand dorsiflexion caused by the posture of opening palm and facing forward was the common ergonomic issue identified from user-defined gestures. In order to reduce discomfort of prolonged gesture controls, the alternative combinations of gestures for accomplishing these tasks was determined based on ergonomic limitations and the considerations of vision-based hand gesture recognitions.

The exploration of non-visual interaction for social proximity applications in a Taiwanese night market

Social Proximity Applications (SPAs) has been an emerging hot topic in recent mobile research communities. However, the traditional SPA interfaces rely on heavy interaction load in visual attention. This is always problematic when people are on the move. This paper describes our research-in-progress in designing and developing a suitable SPA interface for the use in a night market. Night markets embody a distinct cultural habitat for social life in Taiwan. Visitors are continuously bombarded with surrounding information. The results showed our non-visual interaction approach could be a successful means in user interfaces in this type of situations.

The effects of screen size on rotating 3D contents using compound gestures on a mobile device

Abstract The development of mobile devices nowadays shows an increasing trend toward interacting with 3D digital content on a 2D touch screen. However, many issues regarding the appropriateness of the control mode require further exploration. The experimental design in this study designates displays of two sizes—five inches and seven inches—with three groups of hand gestures controlling the X -, Y -, and Z -axis, respectively. The three groups of gestures are compared in terms of how they interact with the 3D content. In the experiment, 30 adult research subjects twice completed a task that involved rotating three 3D immersive-heritage models. Their characteristics, completion time, subjective evaluation, and frequency of gesture change were measured and examined. The results from the experiment and the statistics from a two-way Analysis of Variance (ANOVA) indicate: (1) the display size and the task-completion time are inversely related. Under the effect of the Control–Display ratio, using a smaller display results in a shorter completion time while using a larger display results in a longer completion time; (2) tasks with obvious characteristics for the 3D objects require a shorter time to complete, but those with no obvious characteristics require more time; and (3) using familiar hand gestures leads to a shorter task-completion time, while using unfamiliar hand gestures leads to a longer completion time. The findings of this study show that the Control–Display ratio is an important factor that affects the operational performance of the 3D immersive-heritage model’s rotation tasks completed with hand gestures on small displays. In addition, adaptability and familiarity should be taken into consideration when introducing new hand gestures. Hence, the suggestions in this study constitute important guidelines for museums designing technology for the interaction between mobile devices and 3D immersive-heritage models.

Identifying the Usability Factors of Mid-Air Hand Gestures for 3D Virtual Model Manipulation

Although manipulating 3D virtual models with mid-air hand gestures had the benefits of natural interactions and free from the sanitation problems of touch surfaces, many factors could influence the usability of such an interaction paradigm. In this research, the authors conducted experiments to study the vision-based mid-air hand gestures for scaling, translating, and rotating a 3D virtual car displayed on a large screen. An Intel RealSense 3D Camera was employed for hand gesture recognition. The two-hand gesture with grabbing then moving apart/close to each other was applied to enlarging/shrinking the 3D virtual car. The one-hand gesture with grabbing then moving was applied to translating a car component. The two-hand gesture with grabbing and moving relatively along the circumference of a horizontal circle was applied to rotating the car. Seventeen graduate students were invited to participate in the experiments and offer their evaluations and comments for gesture usability. The results indicated that the width and depth of detection ranges were the key usability factors for two-hand gestures with linear motions. For dynamic gestures with quick transitions and motions from open to close hand poses, ensuring gesture recognition robustness was extremely important. Furthermore, given a gesture with ergonomic postures, inappropriate control-response ratio could result in fatigue due to repetitive exertions of hand gestures for achieving the precise controls of 3D model manipulation tasks.

Age and Gestural Differences in the Ease of Rotating a Virtual 3D Image on a Large, Multi-Touch Screen

Providing a natural mapping between multi-touch gestures and manipulations of digital content is important for user-friendly interfaces. Although there are some guidelines for 2D digital content available in the literature, a guideline for manipulation of 3D content has yet to be developed. In this research, two sets of gestures were developed for experiments in the ease of manipulating 3D content on a touchscreen. As there typically are large differences between age groups in the ease of learning new interfaces, we compared a group of adults with a group of children. Each person carried out three tasks linked to rotating the digital model of a green turtle to inspect major characteristics of its body. Task completion time, subjective evaluations, and gesture changing frequency were measured. Results showed that using the conventional gestures for 2D object rotation was not appropriate in the 3D environment. Gestures that required multiple touch points hampered the real-time visibility of rotational effects on a large screen. While the cumulative effects of 3D rotations became complicated after intensive operations, simpler gestures facilitated the mapping between 2D control movements and 3D content displays. For rotation in Cartesian coordinates, moving one fingertip horizontally or vertically on a 2D touchscreen corresponded to the rotation angles of two axes for 3D content, while the relative movement between two fingertips was used to control the rotation angle of the third axis. Based on behavior analysis, adults and children differed in the diversity of gesture types and in the touch points with respect to the objects contours. Offering a robust mechanism for gestural inputs is necessary for universal control of such a system.

On the implications of sense of control over bicycling: design of a physical stamina-aware bike

Bicycling has become a mainstream activity among the environmental aware generation. Bicycling communities have gradually shown interests in quantitative data of the bicycling experiences such as road roughness, inclination, pollution, etc. Bikers utilize these data to infer the possible stamina cost and quality of surroundings. This supports them to make a better decision. This study assumes that fitness level indexed by stamina cost could enhance a bikers sense of control. The prototype in this paper was developed to provide stamina cost information, which is inferred from the terrain patterns of a biking route. In the system evaluation, participants took a positive attitude toward this prototype and approved the importance of stamina cost feedback. This paper also concluded several key issues about designing the stamina cost feedback system for bikers.