A context-aware reminder system for elders based on fuzzy linguistic approach

To date, several reminder systems for elders have been developed, but when and how to prompt the reminding message has not been fully explored yet. This paper presents a context-aware system that provides reminding messages for elders based on fuzzy linguistic model in order to properly deliver a reminder in an appropriate time and way. By separating the user activity contexts and contexts utilized to trigger a reminder, it is much easier for the elderly or their care givers to schedule and maintain reminders. We first adopt a fuzzy linguistic model to determine the prompting level based on the interrupt degree of user current activity and the urgent level of to-be-prompt reminder. An adaptive mapping strategy is then presented to transfer the prompting level into machine-readable parameters. Finally, the proposed approach is verified through our system prototype and experiments.     

An approach to feature‐based software construction for enhancing maintainability

While the way we build software affects significantly its maintenance in terms of the effort and cost, the experience level of the maintainer in a software acquirers' organization is also one of concern. In this context, often the maintainer is the user of the system. Unfortunately, it is quite possible to lose the trustworthiness of the software due to the inexperience of the maintainer, especially when the maintainer is without the help of the original developers. One remedy for providing security against the effects of the maintainer's software modifications is to restrict the access to software parts (modules) relative to the experience level of the maintainers. For such a remedy to be successful, the software should be constructed in such a way that its parts under maintenance affect others as little as possible. We propose an approach to software construction aligning the dependencies among software parts in one direction so that they are allocated to maintainers based on their experience level. Our approach decomposes the software into parts based on functionality and orders the parts by essentiality, which indicates how difficult it is to change each part. Then, we align the dependencies in such a way that the less essential functionality is dependent on the more essential functionality. Consequently, any modification on less essential functionality does not affect the essential functionalities. To demonstrate the feasibility of our proposed approach, we applied it to a military application and found that the constructed software enables us to confine maintainers' activity within a limited working area, and thus the software is safer against maintainers' modification. Copyright © 2006 John Wiley & Sons, Ltd.     

Development of a statistical model to classify driving stress levels using galvanic skin responses

Many studies have demonstrated the strong relationships between physiological responses and driving stress, but they have done little to build a model that could be used to identify a driver's stress accurately in real time. The objective of this study is to develop a model that accurately classifies driving stress by monitoring physiological responses—specifically galvanic skin response (GSR). GSR data were collected from nine drivers with licenses obtained in the US in real road driving situations with two stress conditions—rest period (low stress) and highway or city driving (high stress). The validation drive was performed by one driver with licenses obtained in South Korea in real long‐term road driving situations with two stress conditions—rural area (low stress) and highway or highway under construction (high stress). Those two conditions were used to build a binary logistic regression model to classify low stress or high stress based on a driver's measured hand GSR. The overall classification accuracy of the developed model was found to be 85.3%, and the accuracy of cross validation, with a testing dataset, was found to be 83.2%. A simple logit model was developed to identify drivers' stress by incorporating their GSR data. The developed model can be embedded in a wearable device equipped with GSR sensors for drivers to detect their stress level in real time.     

Ion sensitive field effect transistor based on graphene and ionophore hybrid membrane for phosphate detection

Microsystem Technologies - This paper reports ion sensitive field effect transistor (IS-FET) with graphene/ionophore hybrid membrane for phosphate detection. CVD graphene is used as a sensing...     

Tuning Interfacial Properties by Spontaneously Generated Organic Interlayers in Top‐Contact‐Structured Organic Transistors

Controlling the interfacial properties between the electrode and active layer in organic field‐effect transistors (OFETs) can significantly affect their contact properties, resulting in improvements in device performance. However, it is difficult to apply to top‐contact‐structured OFETs (one of the most useful device structures) because of serious damage to the organic active layer by exposing solvent. Here, a spontaneously controlled approach is explored for optimizing the interface between the top‐contacted source/drain electrode and the polymer active layer to improve the contact resistance (R_C). To achieve this goal, a small amount of interface‐functionalizing species is blended with the p‐type polymer semiconductor and functionalized at the interface region at once through a thermal process. The R_C values dramatically decrease after introduction of the interfacial functionalization to 15.9 kΩ cm, compared to the 113.4 kΩ cm for the pristine case. In addition, the average field‐effect mobilities of the OFET devices increase more than three times, to a maximum value of 0.25 cm² V^?1 s^?1 compared to the pristine case (0.041 cm² V^?1 s^?1), and the threshold voltages also converge to zero. This study overcomes all the shortcomings observed in the existing results related to controlling the interface of top‐contact OFETs by solving the discomfort of the interface optimization process.     

Prediction of nonrandom mixing in lattice model with multi-references

A new lattice theory is proposed to describe nonrandom mixing behavior based on recently developed lattice model theory by Aranovich and Donohue. The present theory assumes multi-references in order to take into account interference effects on non-random mixing among pairs. The number of references was obtained from Monte Carlo simulations for monomer+hole mixtures. Monte Carlo simulation for hole [0]+monomer [1]+monomer [2] mixture shows that this theory is more accurate than Guggenheim’s quasi-chemical theory or the Aranovich-Donohue model in a wide range of temperatures and densities. Especially, even under the stringent condition of zero interaction energy parameter ε₁₂=0, the present theory predicts well the extent of nonrandom mixing. For dimer fluid the non-randomness is calculated using the surface fraction. Here three references was used as in the case of monomer fluid with chain connectivity constraints. Comparison of the theory with Monte Carlo simulation results for dimer+hole system shows a good agreement.     

Using a Tablet Device to Compensate for Underestimation of Cognitive Function due to Impaired Dominant Hand Function in Stroke Patients

This study aimed to investigate whether a touch-screen tablet device can be used to avoid underestimation of cognitive function due to hand disability in patients with stroke. Thirty patients with stroke and hemiplegia were divided according to whether the paretic side corresponded to their dominant or non-dominant hand. They were given the cube-copying task twice, once via paper and once via tablet. The results between paper- and tablet-based tasks were more likely to be concordant in participants with a non-paretic dominant hand (z = 2.80, p = 0.005) when the stroke type, education years, and sex were included in the model. All participants with discordant test results had a paretic dominant hand and showed lower muscle power in the wrist and hand muscles. In conclusion, cognitive function in patients with a paretic dominant hand may be underestimated in the cube-copying task, because it requires handwriting ability. This could be prevented by using a touch-screen device.     

A time-interleaved recursive loop band-pass delta-sigma modulator for a digital IF CDMA receiver

A bandpass delta-sigma modulator (BPDSM) is a key building block to implement a digital intermediate frequency (IF) receiver in a wireless communication system. This paper proposes a time-interleaved (TI) recursive loop BPDSM architecture that consists of five-stage TI blocks for a code-division multiple-access (CDMA) receiver. The proposed TI BPDSM provides reduction in the clock frequency requirement by a factor of 5 and relaxes the settling time requirement to one-fourth of the conventional approach. The test chip was designed and fabricated for a 30-MHz IF system with a 0.35-/spl mu/m CMOS process. The measured peak SNR for a 1.25-MHz bandwidth is 48 dB while dissipating 75 mW from a 3.3-V supply and occupying 1.3 mm/sup 2/.     

Usability evaluation of symbols in digital cluster for drivers with color vision deficiency

Universal Access in the Information Society - Digital clusters have been adopted as displays in vehicles, and various driving information is presented through the digital clusters with different...     

Exploration on Solvatochromic Sensing Probe of Phenol Blue for L-Lactic Acid Detection: Effective Strategy to Obtain Reliable Capacitive Sensor

This study systematically investigates a capacitive sensor applied with phenol blue (PhB)-based sensing medium for detection of L-lactic acid (LA), as a health monitoring indicator. PhB is a substance with solvatochromic effect, inducing the change in capacitance by exposure to polar molecules. However, the capacitive LA sensor with a flat-structured PhB/polyvinylchloride (PVC) composite-sensing medium is observed to have a problem in that sensing capacitance variation saturate quickly with increasing the LA solution concentration. This main cause can be analyzed that the interaction of proton from LA molecule with the lone pair electrons of the PhB molecule acts as a major factor on the sensing characteristics rather than the solvatochromic behavior of PhB molecule. Therefore, a strategy is adopted to introduce a porous structure to the PhB/PVC composite-sensing medium to maximize the interaction of PhB with protons, which is implemented through solvent and non-solvent exchange methods. Consequently, the sensitivity and linearity of the porous-structured LA sensor are 2.99 pF mm ⁻¹ and 0.966 over LA concentrations ranging from 0 to 100 mm , respectively, which is a significant improvement over that of the flat-structured one. Notably, the sensing performance remained unchanged even after a month of storage under normal ambient conditions.