Finger gesture input utilizing the rear camera of a mobile phone: A perspective of mobile CAD

Various interfaces have been suggested for mobile devices, including touch gesture and embedded sensor‐based interfaces. However, if a user's task requires a thorough look, these interfaces hinder sight of view in display and thus can be inappropriate for the tasks. This problem is more important especially in the mobile computer aided design (CAD) context, which performs visually demanding tasks on the limited screen. To address this point, this study suggests a mobile interface utilizing the rear camera of the device and describes the function mapping for CAD. The suggested interface detects finger attachment and movement direction. The number of colors in camera vision and local binary pattern are used as features, and a support vector machine (SVM) is used for feature classification. A prototype application is designed for validation, and appropriate SVM models are selected through benchmarking tests. The validation results show that the suggested interface can perform with high accuracy and low computational resources.     

Pt Dopant: Controlling the Ir Oxidation States toward Efficient and Durable Oxygen Evolution Reaction in Acidic Media

Dissolution of Ir oxides in Ir‐based catalysts, which is closely linked to the catalyst activity and stability toward the oxygen evolution reaction (OER) in acidic media, is a critical unresolved problem in the commercialization of water electrolysis. Doping foreign elements into the Ir oxides can accomplish an optimal combination of Ir oxidation states that is conducive to the leaching‐resistance of active catalytic sites. Here, it is reported that Pt doping into IrO_x‐based nanoframe is beneficial in both terms of activity and stability. The Pt‐doped IrO_x‐based nanoframe achieves the mass activity of 0.644 A mg^?1_Ir+Pt at 1.53 V_RHE, which is 15‐fold higher than that of the commercial IrO₂. During the accelerated durability test, the Ir^IV‐to‐Ir^III ratio of 5 is maintained in the presence of Pt dopant to effectively mitigate the degradation of Ir catalyst, leading to the superb catalyst durability in acidic media.     

Catalytic Nanoframes and Beyond

The ever-increasing need for the production and expenditure of sustainable energy is a result of the astonishing rate of consumption of fossil fuels and the accompanying environmental problems. Emphasis is being directed to the generation of sustainable energy by the fuel cell and water splitting technologies. Accordingly, the development of highly efficient electrocatalysts has attracted significant interest, as the fuel cell and water splitting technologies are critically dependent on their performance. Among numerous catalyst designs under investigation, nanoframe catalysts have an intrinsically large surface area per volume and a tunable composition, which impacts the number of catalytically active sites and their intrinsic catalytic activity, respectively. Nevertheless, the structural integrity of the nanoframe during electrochemical operation is an ongoing concern. Some significant advances in the field of nanoframe catalysts have been recently accomplished, specifically geared to resolving the catalytic stability concerns and significantly boosting the intrinsic catalytic activity of the active sites. Herein, general synthetic concepts of nanoframe structures and their structure-dependent catalytic performance are summarized, along with recent notable advances in this field. A discussion on the remaining challenges and future directions, addressing the limitations of nanoframe catalysts, are also provided.     

A comparison of heterogeneous video multicast schemes: Layered encoding or stream replication

The heterogeneity of the Internet's transmission resources and end system capability makes it difficult to agree on acceptable traffic characteristics among the multiple receivers of a multicast video stream. Three basic approaches have been proposed to deal with this problem: 1) multicasting the replicated video streams at different rates; 2) multicasting the video encoded in cumulative layers; and 3) multicasting the video encoded in noncumulative layers. Even though there is a common belief that the layering approach is better than the replicated stream approach, there have been no studies that compare these schemes. This paper is devoted to such a systematic comparison. Our starting point is an observation (substantiated by results in the literature) that a bandwidth overhead is incurred by encoding a video stream in layers. We argue that a fair comparison of these schemes needs to take into account this overhead, as well as the specifics of the encoding used in each scheme, protocol complexity, and the topological placement of the video source and the receivers relative to each other. Our results show that the believed superiority of layered multicast transmission relative to replicated stream multicasting is not as clear cut as is widely believed and that there are indeed scenarios where replicated stream multicasting is the preferred approach.     

User Behavior Model Based on Affordances and Emotions: A New Approach for an Optimal Use Method in Product–User Interactions

This study proposes a new approach to developing a user behavior model to explain how a user finds the optimal use. This is achieved by considering user concerns, task significances, affordances, and emotional responses as the interaction components and by exploring behavior sequences for a goal in using a product the first time. The tasks in the same group at each level in the user concern structure are therefore in a competing relationship in going up to a higher task. The task tree with the significances and the affordance probabilities can be analyzed. The order of a user’s exploring behavior sequences can be determined through comparisons of the expected significances, which can be obtained by the modified subjective expected utility theory. A user’s emotional responses for the tasks that a behavior sequence is composed of can be calculated by the modified decision affect theory. Here, the emotional response refers to a user’s internal reactions for the degree to which a product’s affordance features can meet his or her mental model in use. The average emotional response for a behavior sequence can be a user’s decisional factor for the optimal use method in using a product with a goal. Also, the design problems of a product can be checked from users’ point of view, and the emotional losses/changes by usage failures can be discussed. For an illustrative purpose, the proposed model is applied to a numerical example with some assumptions.     

Combined thermal characteristics analysis of steam reforming and combustion for 5 kW domestic PEMFC system

A natural gas-based steam reformer for a domestic polymer electrolyte membrane fuel cell (PEMFC) system is thermodynamically analyzed with a special focus on the heat supply mechanism, which is critical to the endothermic steam reforming process. The interdependence of the reforming and combustion processes is evaluated through a characteristic study of heat transfer from the heat source to the reforming zone. Premixed combustion patterns may be affected by the inclusion of controlling means such as a metal fiber screen or burner placement. In this study, we attempted to enhance reforming performances of a reformer embedded in a 5 kW in-house PEMFC through modification of the combustion pattern by varying the type and placement of the burner and other operating conditions. Reforming input conditions such as steam-carbon ratio (SCR) and fuel distribution ratio (FDR) are also analyzed to quantify the overall performance such as thermal efficiency and fuel conversion rate. In our experiments involving three types of combustors—cylindrical metal fiber burner, flat type metal fiber burner and nozzle-mixing burner—the operating conditions are set so that the SCR and FDR are in the range 3.0–4.0 and 0.4–0.7, respectively. It is found that the cylindrical metal fiber burner at an appropriate location could improve thermal efficiency up to 79% by 10%, compared to other devices. This maximum thermal efficiency output is obtained with 0.63 FDR, which eventually yields 99% hydrogen conversion rate when using a cylindrical metal fiber burner, while the other burners produce 95% conversion. These outputs substantiate that the overall efficiency is strongly affected by an appropriate control for uniform temperature distribution on the catalyst layer.     

Numerical and experimental study on the thermal characteristics of a steam reformer

In this study, the performance evaluation of a cylindrical natural-gas steam reformer is experimentally and numerically performed with a special focus on thermal operation conditions. The evaluation system is configured to probe the thermal and chemical characteristics of a steam reformer that does not employ a high temperature shift and a low temperature shift. The acquired experimental data is used to validate the proposed numerical model. A combination of experimental and numerical data provides detailed information leading to a better understanding of the internal reaction. An appropriate control of the heat source in the steam reformer is extremely important because the endothermic process is dominant throughout the catalyst layer. The results indicate that the thermal efficiency is enhanced by appropriately managing combustor heat, reactant concentration, and inflow rates as implemented by inlet gas control into the main reactor and combustor. A parametric study of operation control variables, such as Steam to carbon ratio (SCR) and combustible reactant ratio, could determine the optimal values for the highest thermal performance.     

Potential Link between Cu Surface and Selective CO2 Electroreduction: Perspective on Future Electrocatalyst Designs

Electrochemical reduction of carbon dioxide (CO₂RR) product distribution has been identified to be dependent on various surface factors, including the Cu facet, morphology, chemical states, doping, etc., which can alter the binding strength of key intermediates such as *CO and *OCCO during reduction. Therefore, in-depth knowledge of the Cu catalyst surface and identification of the active species under reaction conditions aid in designing efficient Cu-based electrocatalysts. This progress report categorizes various Cu-based electrocatalysts into four main groups, namely metallic Cu, Cu alloys, Cu compounds (Cu + non-metal), and supported Cu-based catalysts (Cu supported by carbon, metal oxides, or polymers). The detailed mechanisms for the selective CO₂RR are presented, followed by recent relevant developments on the synthetic procedures for preparing Cu and Cu-based nanoparticles. Herein, the potential link between the Cu surface and CO₂RR performance is highlighted, especially in terms of the chemical states, but other significant factors such as defective sites and roughened morphology of catalysts are equally considered during the discussion of current studies of CO₂RR with Cu-based electrocatalysts to fully understand the origin of the significant enhancement toward C₂ formation. This report concludes by providing suggestions for future designs of highly selective and stable Cu-based electrocatalysts for CO₂RR.     

Reduced complexity sequence detection for high-order partialresponse channels

Detector hardware complexity of high-order partial response magnetic read channels is a major obstacle to high data rate operation and reduced area and power consumption. The method presented here reduces the complexity of single-step and two-step implementations of the Viterbi detector by applying a distance-enhancing code that eliminates some states from the code trellis. The complexity of the detector is further reduced by eliminating less-probable branches from the trellis. This is accomplished by a simple control mechanism that uses the signs of the consecutive input samples. The reduced set of add-compare-select (ACS) units is dynamically assigned to the detector states, decreasing the complexity of the Viterbi detector by roughly 50%. This method is demonstrated on high-order partial response systems with the E²PR4 target and an 11-level/32-state target. The simulation results show negligible bit error rate (BER) degradation for signal-to-noise ratios In the range of operation of contemporary disk drive read channels