Green product design through product modularization using atomic theory

With increasing environmental consciousness and the establishment of environmental protection regulations, green product design not only plays a crucial role in a modern industry but is also becoming the main focus of the future market. In this paper, an innovative method is presented that uses the concepts of atomic theory to solve design modularization problems for green product design. With the developed method, products can be modularized based upon given green constraints, e.g., material compatibility, part recyclability, and part disassemblability. The developed method can help engineers effectively create green designs in the initial design stage, based on product lifecycle requirements. With green considerations incorporated into new modules, a new design can be created that improves upon an original design, with respect to environmental impacts. Product designers can use our method to compare differences between their original designs and the new green modules and then perform necessary design modifications. A table lamp and a motor are used as case study examples to show the effectiveness of the atomic-theory-based green product design method.     

Determinants of users’ intention to adopt wireless technology: An empirical study by integrating TTF with TAM

This paper reported the results of a survey study and provided evidences of empirically testing a model that integrates both technology acceptance model (TAM) and task-technology fit (TTF) model in understanding the determinants of users’ intention to use wireless technology in organizations. Questionnaires were distributed to organizations that bring mobile commerce into practice through the wireless handheld devices. The results indicated that both technology acceptance model and task-technology fit model are robust models by themselves. First, both perceived usefulness and ease of use significantly influence users’ behavior intention to utilize wireless technology. Perceived ease of use has significant effect on perceived usefulness. Second, characteristics of technology and task significantly predict the fit between these two constructs. Significant effect of characteristics of technology on perceived ease of use and usefulness were observed. Finally, significant relationships between TAM and TTF model were also observed. Task-technology fit is a significant direct predictor of technology adoption intention. Overall, users’ intention to adopt wireless technology in organizations was determined directly by fit between characteristics of task and technology as well as users’ perceived ease of use and usefulness.     

Success of electronic commerce Web sites: A comparative study in two countries

This study incorporated attitude toward a site (Ast) in the proposed model together with moderating factors like cultural effects and attitude toward online shopping (Ashop). The proposed model and hypotheses were partially supported in Taiwan's and Thailand's data. Information quality affected both user satisfaction and attitude toward the web site and was the dimension common across both countries. Ashop moderated the effects of system quality on user satisfaction in Taiwan, but moderated information quality in the Thailand. National identity moderated the effect of system quality on both user satisfaction and attitude toward the site in the Thai data.     

NDM-Based Cognitive Agents for Supporting Decision-Making Teams

Naturalistic decision making (NDM) focuses on how people actually make decisions in realistic settings that typically involve ill-structured problems. Taking an experimental approach, we investigate the impacts of using an NDM-based software agent (R-CAST) on the performance of human decision-making teams in a simulated C3I (Communications, Command, Control and Intelligence) environment. We examined four types of decision-making teams with mixed human and agent members playing the roles of intelligence collection and command selection. The experiment also involved two within-group control variables: task complexity and context switching frequency. The result indicates that the use of an R-CAST agent in intelligence collection allows its team member to consider the latest situational information in decision making but might increase the team member's cognitive load. It also indicates that a human member playing the role of command selection should not rely too much on the agent serving as his or her decision aid. Together, it is suggested that the roles of both humans and cognitive agents are critical for achieving the best possible performance of C3I decision-making teams: Whereas agents are superior in computation-intensive activities such as information seeking and filtering, humans are superior in projecting and reasoning about dynamic situations and more adaptable to teammates' cognitive capacities. This study has demonstrated that cognitive agents empowered with NDM models can serve as the teammates and decision aids of human decision makers. Advanced decision support systems built upon such team-aware agents could help achieve reduced cognitive load and effective human-agent collaboration.     

Identification and verification of chaotic dynamics in a missile system from experimental time series

This article is concerned with the chaotic dynamics in a missile system. Five channels of acceleration signals were measured at different locations and/or orientations of the missile during a test flight. Based on these data, the existence of chaotic behaviour is determined using common techniques for nonlinear time series analysis, such as phase-space reconstruction, Poincaré map, correlation dimension and maximum Lyapunov exponent. It is found that the vibration behaviour of the missile system represents high-order (eight dimensional) chaos. Chaotic dynamics exist in three (out of the five) channels of acceleration signals. As typical in experimental time series, the acceleration signals are contaminated with random noises. In order to determine whether deterministic chaos dominates in the three acceleration signals, a sequence of two statistical tests, the BDS test and the Kaboudan test, is applied. The BDS test rules out the possibility that the three acceleration signals are purely random. The subsequent Kaboudan test indicates that deterministic chaotic dynamics indeed dominate in two acceleration signals where the seeker is located.     

Determination of shallow water depth using optical satellite images

The Penghu archipelago comprises 64 basaltic volcanic isles lying on the Taiwan Strait between mainland China and Taiwan. The water around and within these isles is shallow and poses considerable difficulty in echo sounding detection for bathymetry. Most existing bathymetry data around such areas are in water depths of greater than 5 m. Therefore, when the water depth is less than 5 m the data tend to be over-extrapolated. In this study, a remote sensing method provides a more effective approach to recording shallow water depths compared to traditional soundings using multitemporal images collected by optical/near-infrared sensors from SPOT satellites. This method employs optical energy reflections to obtain the water depth. In this study, we made several improvements wherein a relative atmosphere correction technique was used to calibrate two images within a similar atmospheric condition. We then compared the satellite images acquired from different dates to obtain the local water attenuation coefficient of sunlight. Finally, we developed a means to estimate the water attenuation coefficient and bottom reflectance which will satisfy the two parameters across the study area. Our results show a high-resolution map of shallow bathymetry for the Penghu archipelago and revealed a maximum depth of about 20 m. This study provides an efficient approach for shallow bathymetry retrieval. Many detailed features revealed by this approach may contribute to further geological research and developments in harbour and coastal engineering.     

Robust tracking control for a class of electrically driven flexible-joint robots without velocity measurements

This article addresses the motion tracking control for a class of flexible-joint robotic manipulators actuated by brushed direct current motors. This class of electrically driven flexible-joint robots is perturbed by time-varying parametric uncertainties and external disturbances. A novel observer-based robust dynamic feedback tracking controller without velocity measurements will be developed such that the resulting closed-loop system is locally stable, all the states and signals are bounded and the trajectory tracking errors can be made as small as possible. Only the measurements of link position and armature current are required for feedback and so the number of sensors in the practical implementation of the developed control scheme can be greatly reduced. The observer structure is of reduced order in the sense that the observer is constructed only to estimate the velocity signals and whose dimension is half of the dimension of flexible-joint robots. Especially, for the set-point regulation problem, the developed controller is simplified to a linear time-invariant controller. Consequently, the robust tracking control scheme developed in this study can be extended to handle a broader class of uncertain electrically driven flexible-joint robots and the developed robust control schemes possess the properties of computational simplicity and easy implementation. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control algorithms.     

The optimal retailer's ordering policies with trade credit financing and limited storage capacity in the supply chain system

The traditional economic order quantity model assumes that the retailer's storage capacity is unlimited. However, as we all know, the capacity of any warehouse is limited. In practice, there usually exist various factors that induce the decision-maker of the inventory system to order more items than can be held in his/her own warehouse. Therefore, for the decision-maker, it is very practical to determine whether or not to rent other warehouses. In this article, we try to incorporate two levels of trade credit and two separate warehouses (own warehouse and rented warehouse) to establish a new inventory model to help the decision-maker to make the decision. Four theorems are provided to determine the optimal cycle time to generalise some existing articles. Finally, the sensitivity analysis is executed to investigate the effects of the various parameters on ordering policies and annual costs of the inventory system.     

Mental map preserving graph drawing using simulated annealing

Visualizing graphs has been studied extensively in the community of graph drawing and information visualization over the years. In some applications, the user is required to interact with a graph by making slight changes to the underlying graph structure. To visualize graphs in such an interactive environment, it is desirable that the differences between the displays of the original and the modified graphs be kept minimal, allowing the user to comprehend the changes in the graph structure faster. As the mental map concept refers to the presentation of a person’s mind while exploring visual information, the better the mental map is preserved, the easier the structure change of a graph is understood. It is somewhat surprising that preserving the user’s mental map has largely been ignored in the graph drawing community in the past. We propose an effective mental-map-preserving graph drawing algorithm for straight-line drawings of general undirected graphs based on the simulated-annealing technique. Our experimental results and questionnaire analysis suggest this new approach to be promising.     

Surface deformation from persistent scatterers SAR interferometry and fusion with leveling data: A case study over the Choushui River Alluvial Fan, Taiwan

The Choushui River Alluvial Fan (CRAF), one of the most important agricultural areas in Taiwan, suffers severe subsidence caused by groundwater withdrawal. We use 20 ENVISAT images from 2006 to 2008 to derive vertical deformation over CRAF by persistent scatterer interferometry (PSI), which effectively reduces errors affecting conventional DInSAR techniques. The pixel density over CRAF is 107.6 pixels/km², compared to 0.19 points/km² of the leveling benchmarks. PSI yields vertical displacements matching the leveling result to 0.6 cm/year (RMS), and provides a higher spatial resolution of subsidence than the latter. We also develop a data fusion method that considers the high-precision, low point-density leveling result as a smoothed correction to the PSI result. The combined field is more representative of overall deformation characteristics than the PSI-only or leveling-only field, and it is better suited for the assessment of the impact of subsidence over CRAF.