An Empirical Study of Consumer Adoption of Internet of Things Services

Internet of things (IoT) is considered as a next-generation digital revolution to connect things with an embedded system to the Internet, which will lead to dramatic changes in our lives. The purpose of this paper is to identify the antecedents of consumers’ attitudes toward IoT, and test their influences on the attitudes and behaviors of consumers. To reach the research goal, this paper develops and tests factors determining user acceptance of IoT services by using an extended unified theory of acceptance and use of technology (UTAUT) model, which includes a factor of the hindering condition. Based on the structural equation modeling (SEM) analysis of 224 survey responses, the result shows that performance expectancy, social influence, facilitating condition, and hindering condition have a strong effect on behavioral intention to use IoT services, but effort expectancy does not support the relationship with behavioral intention

High performance gas sensor platform based on integrated sensing mechanisms

We introduce a gas sensor platform consisting of resistive sensor, thin film transistor (TFT) type sensor, and Si-based field effect transistor (FET) type sensor fabricated on the same wafer. The FET type sensor has a horizontal floating gate interdigitated with the control gate. The schematic structures of these gas sensors are shown in Fig. 1. These gas sensors can be fabricated using only 5 masks. The sensing layer of these sensors is a 15nm thick n-type ZnO film prepared using atomic layer deposition (ALD) in the final process step. Although these sensors have the same sensing material, they have different sensing characteristics because of different sensing mechanisms. Our group has reported the studies of resistive- and FET-type gas sensors having ALD ZnO sensing layer previously [1], [2]. Fig. 2 shows the transfer (I-V) characteristics of these sensors. These sensors have different sensing characteristics when exposed to 500 ppb of oxidizing gas, NO2. When exposed to NO2 gas, the currents of resistive- and TFT-type gas sensors are decreased [2]. On the other hand, the drain current of the FET-type gas sensor increases when exposed to NO2 gas [1], [2]. As a result, the difference in response of these sensors can be used as a fingerprint to more accurately detect the target gas in the gas sensor platform composed of three types of gas sensors. Please click Additional Files below to see the full abstract

Recovery of off-state stress-induced damage in FET-type gas sensor using self-curing method

The need for high-performance gas sensors is driven by concerns over indoor and outdoor air quality, and industrial gas leaks. Due to their structural diversity, vast surface area, and geometric tunability, metal oxides show significant potential for the development of gas sensing systems. Despite the fact that several previous reports have successfully acquired a suitable response to various types of target gases, it remains difficult to maintain the reliability of metal oxide-based gas sensors. In particular, the degradation of the sensor platform under repetitive operation, such as off-state stress (OSS) causes significant reliability issues. We investigate the impact of OSS on the gas sensing performances, including response, low-frequency noise, and signal-to-noise ratio of horizontal floating-gate field-effect-transistor (FET)-type gas sensors. The 1/f noise is increased after the OSS is applied to the sensor because the gate oxide is damaged by hot holes. Therefore, the SNR of the sensor is degraded by the OSS. We applied a self-curing method based on a PN-junction forward current at the body–drain junction to repair the damaged gate oxide and improve the reliability of the sensor. It has been demonstrated that the SNR degradation caused by the OSS can be successfully recovered by the self-curing method

An Empirical Study of Consumer Adoption of Internet of Things Services

Internet of things (IoT) is considered as a next-generation digital revolution to connect things with an embedded system to the Internet, which will lead to dramatic changes in our lives. The purpose of this paper is to identify the antecedents of consumers’ attitudes toward IoT, and test their influences on the attitudes and behaviors of consumers. To reach the research goal, this paper develops and tests factors determining user acceptance of IoT services by using an extended unified theory of acceptance and use of technology (UTAUT) model, which includes a factor of the hindering condition. Based on the structural equation modeling (SEM) analysis of 224 survey responses, the result shows that performance expectancy, social influence, facilitating condition, and hindering condition have a strong effect on behavioral intention to use IoT services, but effort expectancy does not support the relationship with behavioral intention

Uncertainty quantification of borehole heat exchanger design length based on a global sensitivity analysis

Ground heat exchangers are essential components of ground-source heat pump systems. One of the most-used ground heat exchanger types is a borehole heat exchanger (BHE). Many parameters, such as the building thermal loads, ground thermal properties, and BHE components, influence the required BHE length. Therefore, understanding how individual parameter uncertainties are propagated to the output is counterintuitive. In this study, a global sensitivity analysis (GSA) was performed using the framework of the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) BHE design method. The GSA was conducted to identify the subparameters behind the input parameters of ASHRAE design method, which indirectly determine the BHE lengths by impacting the direct input parameters in the ASHRAE formula. The results reveal that the zone infiltration, heat pump efficiency, ground temperature, effective borehole thermal resistance, and electric equipment heat gain are the most influential parameters on the BHE design length

Visible-Light-Induced 1,3-Aminopyridylation of [1.1.1]Propellane with N-Aminopyridinium Salts

Through the formation of an electron donor-acceptor (EDA) complex, strain-release aminopyridylation of [1.1.1]propellane with N-aminopyridinium salts as bifunctional reagents enabled the direct installation of amino and pyridyl groups onto bicyclo[1.1.1]pentane (BCP) frameworks in the absence of an external photocatalyst. The robustness of this method to synthesize 1,3-aminopyridylated BCPs under mild and metal-free conditions is highlighted by the late-stage modification of structurally complex biorelevant molecules. Moreover, the strategy was extended to P-centered and CF3 radicals for the unprecedented incorporation of such functional groups with pyridine across the BCP core in a three-component coupling. This practical method lays the foundation for the straightforward construction of new valuable C4-pyridine-functionalized BCP chemical entities, thus significantly expanding the range of accessibility of BCP-type bioisosteres for applications in drug discovery.11Nsciescopu

Stage IV Wilms Tumor Treated by Korean Medicine, Hyperthermia and Thymosin-α1: A Case Report

Introduction: Wilms tumor is one of general solid cancers that occur in children, which carries a death rate of 7-8 in a million. The cure rate of Wilms tumor in the recent 30 years has dramatically been improved, but a proper remedy is still not prepared enough in terms of application in tumor therapy upon recurrence after radiotherapy, surgery and chemotherapy. We present an integrative medical remedy - hyperthermia and thymosin-α1 treatment focused on herbal remedy - since there have been cases in which this remedy contributed to remission in the liver-transferred part in the 4th phase of Wilms tumor and stable maintenance of metastatic lung lesion. Case Presentation: Our patient, a female Korean mongoloid outpatient, was treated from October 25, 2014, to July 22, 2015. The herbal remedy consisted of 8 ml inhalation of Soram nebulizer solution q.d., Soramdan S 8 g p.o., Hangamdan S 1 g p.o., t.i.d., Cheongjangtang 10-30 ml, and Spiam HC 8 g p.o. The integrative medical therapy was done with hyperthermia therapy (oncothermia) and 1.6 mg of thymosin-α1 treatment (Zadaxin) i.m. According to the CT result on July 15th, 2015, the liver metastasis was not seen anymore, while the lung metastasis was maintained stably without tumor progress. Conclusions: Accompanying integrative medical therapy with herbal remedy in the treatment of Wilms tumor showing progress patterns after surgery and chemotherapy can be meaningful as a new remedy

An Efficient Three-Dimensional Convolutional Neural Network for Inferring Physical Interaction Force from Video

Interaction forces are traditionally predicted by a contact type haptic sensor. In this paper, we propose a novel and practical method for inferring the interaction forces between two objects based only on video data—one of the non-contact type camera sensors—without the use of common haptic sensors. In detail, we could predict the interaction force by observing the texture changes of the target object by an external force. For this purpose, our hypothesis is that a three-dimensional (3D) convolutional neural network (CNN) can be made to predict the physical interaction forces from video images. In this paper, we proposed a bottleneck-based 3D depthwise separable CNN architecture where the video is disentangled into spatial and temporal information. By applying the basic depthwise convolution concept to each video frame, spatial information can be efficiently learned; for temporal information, the 3D pointwise convolution can be used to learn the linear combination among sequential frames. To validate and train the proposed model, we collected large quantities of datasets, which are video clips of the physical interactions between two objects under different conditions (illumination and angle variations) and the corresponding interaction forces measured by the haptic sensor (as the ground truth). Our experimental results confirmed our hypothesis; when compared with previous models, the proposed model was more accurate and efficient, and although its model size was 10 times smaller, the 3D convolutional neural network architecture exhibited better accuracy. The experiments demonstrate that the proposed model remains robust under different conditions and can successfully estimate the interaction force between objects

Effects of Electrode Structure on H2S Sensing and Low-Frequency Noise Characteristics in In2O3-Based Resistor-Type Gas Sensors

© 2001-2012 IEEE.Most studies on gas sensors are focusing on improving the response of the sensor. However, noise characteristics should also be considered for the design of gas sensors with optimal performance. This paper investigates the effects of electrode structure on H2S gas sensing and low-frequency noise (LFN) characteristics in In2O3 resistor-type gas sensors. We mainly analyze the response and noise performances of the interdigitated electrode (IDE) sensors with different combinations of spacing between the fingers ( ${S}_{\mathrm{f}}$ ) and the number of electrode fingers ( ${N}_{\mathrm{f}}$ ). Parallel electrode (PE) sensors are also compared as a reference. For the IDE sensors, the response increases as the ${S}_{\mathrm{f}}$ decreases (or Nf increases), while the PE sensors show constant response regardless of the ${S}_{\mathrm{f}}$. The gas response characteristics of the IDE and PE sensors are further analyzed using the gas sensing results of a transmission line method (TLM) pattern. It is shown that the contributions of bulk and contact to the overall gas response differ depending on electrode spacing. The normalized LFN of the IDE sensors is at least 100 times smaller than that of the PE sensors since ${S}_{\mathrm{f}}$ greatly affects the noise characteristics. The limit of detection (LOD) of the sensor for H2S gas can be improved from 8380 ppb ( ${S}_{\mathrm{f}}= 100\,\,\mu \text{m}$ , ${N}_{\mathrm{f}} = 2$ ) to 6.42 ppb ( ${S}_{\mathrm{f}}= 2\,\,\mu \text{m}$ , ${N}_{\mathrm{f}} = 30$ ) by adopting a shortly spaced interdigitated electrode structure. The results provide an electrode design guidance for the resistor-type gas sensors that show optimal performance considering both the noise and gas response.N