Task Modeling by the Keywords Extracted from Manual Pages

A task modeling method using keywords related to the functions of commands for intelligent user interfaces is proposed. A task model is a description of functions and operations of the computer. The task model is described as the name of a task in our method. We define the name of a task as the minimal set of common keywords which definitely distinguish the task. For the name of a task, keywords indicating the concepts of each command are needed. Since the order of the number of the keywords is that of the number of the commands, it is much easier to implement this method than a procedural knowledge based one. We also propose a method to extract the keywords automatically from the manual pages, the on-line reference manuals for UNIX. Since almost every command is associated with manual pages, the task names can be easily updated when a new command is added to the system. To show the effectiveness of the task names and the keywords extracted from the manual pages, we direct our attention to users' command histories. We show the effectiveness of these keywords by showing the relationship between the tasks in the history and the task names through statistical analysis

Improvement of dye-sensitized solar cells toward the broader light harvesting of the solar spectrum

Dye-sensitized solar cells (DSSCs) have been extensively evolved for the past two decades in order to improve their cell performance. From the commercialization point of view, the overall solar to electrical energy conversion efficiency should compete with other solar cells. But, due to structural restrictions of DSSC using the liquid electrolyte and a space requirement between two electrodes, the direct tandem construction of DSSCs by stacking of repeating units is highly limited. In this feature article, important research trials to overcome these barriers and a recent research trend to improve the light harvesting strategies mainly panchromatic engineering, various tandem approaches such as parallel tandem, series tandem, p-n tandem etc., have been briefly reviewed.close271

Organic-inorganic hybrid perovskite materials for flexible energy devices

School of Molecular Sciences(Chemical Engineering)Photovoltaic (PV) devices, which directly converts the photons to electricity, can be regarded as one of the promising solution for increasing energy demands and concerns environmental pollutions induced by fossil fuels. Organic-inorganic hybrid perovskite solar cells (PSCs) have received considerable attention within few years, due to their excellent electrical and optical properties. Their performance has rapidly improved reaching efficiency as high as certified value of 20.1%. However, to reduce the cost for production of photovoltaics and give direction towards potential application such as wearable electronic textiles, bendable display devices, and portable electronic chargers, fabricating them onto flexible substrate should be realized. So far, most of flexible PSCs (FPSCs) have been prepared on a plastic substrate. However, there is limitation for calcination of TiO2 electrode, which is most often used for electron transport materials because it is still holding the efficiency record as well as mesoporous TiO2 layer can solve the hysteresis problem of perovskite solar cells, at high temperature onto plastic based substrate due to their thermal instability. Metal substrate such as Ti, and stainless steel can be considered as viable alternative to plastic substrate. Metallic foils can provide several advantages such as superior mechanical and thermal stability. Furthermore, they have greater electrical conductivity and low materials cost. Although metal substrates offer promising properties, they have the key obstacle to fabricate with conventional metal top electrode due to their opacity. Since the light cannot penetrate though metal substrate, metal top electrodes should be replaced with transparent conducing materials. My thesis presents three different approaches that are aimed at contributing to the development of transparent and conductive top electrodes for integrating FPSCs into metal substrate. At first, I present silver thin film as a semitransparent top electrode in metal based FPSCs. Since the thickness of the Ag layer controls the number of photons penetrating into the active layer and the collecting ability, optimizing the thickness of Ag layer is needed. I have varied the thickness of the Ag layer, the performance and properties are addressed this part. Second, I report indium tin oxide (ITO) for top electrode in a PSCs. ITO has been used as a transparent conducting electrode for photovoltaic devices due to its advantages such as low electrical resistivity, structural uniformity, and high transparency compared with those of other promising transparent conducting materials. Although ITO has superior characteristics, its inherent brittleness has limited its use in flexible electrode applications. I suggest that the insertion of an ultra-thin Ag layer (1-3 nm) by thermal evaporation between spiro-MeOTAD and ITO may be a solution to enhance the performance and brittleness issue in devices. Third, I introduce silver nanowires (AgNWs) for top electrode deposited using spray coating methods. Fully solution based indium-free flexible photovoltaics, which has advantages in terms of price and process, have potentials to be made scalable commercial production. Moreover, efficient fiber-shaped perovskite photovoltaics with AgNWs as top electrode would be addressed for future electronic systems. The processes were all fully solution-based, and are therefore feasible for large-scale industrial production. These strategy in my thesis expected to provide important insight into design of next generation photovoltaic cells.ope

Distortion Correction for 3D Scan of Trunk Swaying Human Body Segments

We propose a method for acquiring a 3D shape of human body segments accurately. Using a light stripe triangulation range finder, we can acquire accurate 3D shape of a motionless object in dozens of seconds. If the object moves during the scanning, the acquired shape would be distorted. Naturally, humans move slightly for making balance while standing even if the subject makes an effort to stay still for avoiding the distortion in acquired shape. Our method corrects the distortion based on measured subject's motion during the scanning. Experimental results show the accuracy of the proposed method. Trunk swaying degrades the accuracy of the light stripe triangulation from 1mm to 10mm. We can keep the accuracy of as good as 2mm by applying our method