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Augmenting On-Body Touch Input with Tactile Feedback Through Fingernail Haptics
No full textThe key assumption attributed to on-body touch input is that the skin being touched provides natural tactile feedback. In this paper, we for the first time systematically explore augmenting on-body touch input with computer-generated tactile feedback. We employ vibrotactile actuation on the fingernail to couple on-body touch input with tactile feedback. Results from our first experiment show that users prefer tactile feedback for on-body touch input. In our second experiment, we determine the frequency thresholds for rendering realistic tactile "click"sensations for on-body touch buttons on three different body locations. Finally, in our third experiment, we dig deeper to render highly expressive tactile effects with a single actuator. Our non-metric multi-dimensional analysis shows that haptic augmentation of on-body buttons enhances the expressivity of on-body touch input. Overall, results from our experiments reinforce the need for tactile feedback for on-body touch input and show that actuation on the fingernail is a promising approach
A hybrid machine learning approach to investigate the changing urban thermal environment by dynamic land cover transformation: A case study of Suwon, republic of Korea
No full textUrban thermal environment should be analyzed by considering the dynamic structural changes as cities grow both horizontally and vertically. Local Climate Zone (LCZ) scheme can describe built-up areas in detail, mainly based on density and height; however, the low overall accuracy of LCZ urban classes (OAurb) remains a notable limitation that requires improvement. This study proposes a hybrid analytical method considering bidirectional urban expansion and low OAurb. Temporal LCZ maps were constructed using a convolutional neural network to observe the dynamic urban growth between 2004 and 2021 in Suwon, South Korea. Unlike previous LCZ mapping studies, we utilized the additional information provided by deep learning through softmax-based probability maps. Random forest-based downscaling models were developed by combining various auxiliary variables related to the Land Surface Temperature (LST) to observe the detailed surface energy flux. A filtering method was then employed by eliminating areas where LCZs were identified with a low confidence level using extracted probability maps. Finally, thermal variability was investigated by overlaying the filtered LCZ maps and the corresponding LST. The produced LCZ maps and spatially downscaled LSTs accurately depicted dynamic urban form changes, with the LCZ maps exhibiting an average overall accuracy of approximately 90% and downscaled LSTs showing an average coefficient of determination of ??? 0.9 and a root mean square error of 0.7 ??C. Thermal variability occurring due to structural transitions varied in magnitude depending on the height and density of the buildings, while exhibiting a maximum and minimum value of 2.8 ??C and ??? 2.2 ??C, respectively. By selecting reliably classified areas, the proposed filtering method produced more rational results than the original non-filtering method, resulting in higher variability from ??? 0.4 ??C to 0.6 ??C
The Effect of Shortening the Quarantine Period and Lifting the Indoor Mask Mandate on the Spread of COVID-19: A Mathematical Modeling Approach
No full textIn this paper, we present a mathematical model to assess the impact of reducing the quarantine period and lifting the indoor mask mandate on the spread of Coronavirus Disease 2019 (COVID-19) in Korea. The model incorporates important epidemiological parameters, such as transmission rates and mortality rates, to simulate the transmission of the virus under different scenarios. Our findings reveal that the impact of mask wearing fades in the long term, which highlights the crucial role of quarantine in controlling the spread of the disease. In addition, balancing the confirmed cases and costs, the lifting of mandatory indoor mask wearing is cost-effective; however, maintaining the quarantine period remains essential. A relationship between the disease transmission rate and vaccine efficiency was also apparent, with higher transmission rates leading to a greater impact of the vaccine efficiency. Moreover, our findings indicate that a higher disease transmission rate exacerbates the consequences of early quarantine release
The quantum threat to blockchain: summary and timeline analysis
No full textBlockchain technology has emerged in the last decade and has been increasingly adopted in real-world applications. It relies on several cryptographic techniques, namely cryptographic hashing and digital signatures, which are threatened by the development of quantum computers. Quantum computing can potentially implement algorithms which can invalidate assumptions underlying these systems, namely pre-image resistance, and the intractability of certain hidden subgroup problems. Several research works have investigated the nature of the threats posed by quantum computing to blockchain, and have proposed potential countermeasures to secure the systems. In this paper we will analyse the timeline along which such threats are likely to become real for blockchain implementations, and assess the level of threat posed given the proposed countermeasures. After providing a reasoned summary of the quantum computing threats to blockchain and possible solutions, we discuss the time frame within which, by integrating the insights provided by recent research on their evolution, quantum computers may become mature enough to support the implementation of algorithms that could actually break the current public blockchain implementations, like Bitcoin
Thickness of hydrogel for nitrifying biomass entrapment determines the free ammonia susceptibility differently in batch and continuous modes
No full textHydrogels immobilizing nitrifying bacteria with different thicknesses of 0.55 and 1.13 cm (HG-0.55 and HG-1.13, respectively) were produced. It was recognized that the thickness of media is a crucial parameter that affects both the stability and efficiency of wastewater treatment. Batch mode experiments were conducted to quantify specific oxygen uptake rate (SOUR) values at various total ammonium nitrogen (TAN) concentrations and pH levels. In the batch test, HG-0.55 exhibited 2.4 times higher nitrifying activity than HG-1.13, with corresponding SOUR values of 0.00768 and 0.00317 mg-O-2/L mL-PVA min, respectively. However, HG-0.55 was more susceptible to free ammonia (FA) toxicity than HG-1.13, resulting in a reduction of 80% and 50% in SOUR values for HG-0.55 and -1.13, respectively, upon increasing the FA concentration from 15.73 to 118.12 mg-FA/L. Continuous mode experiments were conducted to assess the partial nitritation (PN) efficiency in practical applications, where continuous wastewater inflow maintains low FA toxicity through high ammonia-oxidizing rates. With step-wise TAN concentration increases, HG-0.55 experienced a gentler increase in FA concentration compared to HG-1.13. At a nitrogen loading rate of 0.78-0.95 kg-N/m(3) day, the FA increase rate for HG-0.55 was 0.0179 kg-FA/m(3) day, while that of HG-1.13 was 0.0516 kg-FA/m(3) day. In the batch mode, where wastewater is introduced all at once, the high accumulation of FA posed a disadvantage for the FA-susceptible HG-0.55, which made it unsuitable for application. However, in the continuous mode, the thinner HG-0.55, with its larger surface area and high ammonia oxidation activity, proved to be suitable and demonstrated its effectiveness. This study provides valuable insights and a framework for the utilization strategy of immobilized gels in addressing the toxic effects of FA in practical processes