A fire detector is the most important component in a fire alarm system. Herein, we present the feasibility of a highly sensitive and rapid response gas sensor based on metal oxides as a high ...performance fire detector. The glancing angle deposition (GLAD) technique is used to make the highly porous structure such as nanocolumns (NCs) of various metal oxides for enhancing the gas-sensing performance. To measure the fire detection, the interface circuitry for our sensors (NiO, SnO₂, WO₃ and In₂O₃ NCs) is designed. When all the sensors with various metal-oxide NCs are exposed to fire environment, they entirely react with the target gases emitted from Poly(vinyl chlorides) (PVC) decomposed at high temperature. Before the emission of smoke from the PVC (a hot-plate temperature of 200 °C), the resistances of the metal-oxide NCs are abruptly changed and SnO₂ NCs show the highest response of 2.1. However, a commercial smoke detector did not inform any warning. Interestingly, although the NiO NCs are a
-type semiconductor, they show the highest response of 577.1 after the emission of smoke from the PVC (a hot-plate temperature of 350 °C). The response time of SnO₂ NCs is much faster than that of a commercial smoke detector at the hot-plate temperature of 350 °C. In addition, we investigated the selectivity of our sensors by analyzing the responses of all sensors. Our results show the high potential of a gas sensor based on metal-oxide NCs for early fire detection.
The realization of high‐contrast modulation in optically transparent media is of great significance for emerging mechano‐responsive smart windows. However, no study has provided fundamental ...strategies for maximizing light scattering during mechanical deformations. Here, a new type of 3D nanocomposite film consisting of an ultrathin (≈60 nm) Al2O3 nanoshell inserted between the elastomers in a periodic 3D nanonetwork is proposed. Regardless of the stretching direction, numerous light‐scattering nanogaps (corresponding to the porosity of up to ≈37.4 vol%) form at the interfaces of Al2O3 and the elastomers under stretching. This results in the gradual modulation of transmission from ≈90% to 16% at visible wavelengths and does not degrade with repeated stretching/releasing over more than 10 000 cycles. The underlying physics is precisely predicted by finite element analysis of the unit cells. As a proof of concept, a mobile‐app‐enabled smart window device for Internet of Things applications is realized using the proposed 3D nanocomposite with successful expansion to the 3 × 3 in. scale.
Mechano‐responsive smart windows are developed using stretchable 3D hybrid nanocomposites. The inserted periodic oxide nanoshell in the elastomer offers formation of light scattering air gaps upon stretching, and this provides high‐contrast optical modulation. It is demonstrated that smart window devices can be prepared for self‐responding to the surrounding environments and temporary projection screens by integrating with Internet of Things technology.
Our world is quickly moving towards the fourth industrial revolution including mobile, big data, AI, IoT, cloud computing, VR, etc. Recently, South Korea has been emphasizing convergence education to ...university. Thus, university has begun doing convergence education on their own by linking major subjects and liberal arts courses or linking different departments. In this paper, we analyzed learners’ satisfaction for operating convergence education effectively to increase education satisfaction and developed convergence curriculum and convergence skills required by society. for this study, a satisfaction survey is conducted for students majoring in engineering colleges. And the students’ experiences are collected through interviews and questionnaires for suggesting improved the convergence curriculum operation. We also did interviews and asked students about the meaning convergence education had for them, the impressions they had after taking the classes, and any opinions for further improvements. As a result of the analysis of student's satisfaction and satisfaction of convergence curriculum, it was analyzed as “approximately satisfied†with 3.6. Additionally, the correlation between student satisfaction and convergence curriculum satisfaction was analyzed, and the correlation coefficient showed a significant correlation with 0.732. In other words, it can be seen that students with high-student satisfaction are also highly satisfied with the convergence curriculum. Based on the result of the research and the student’s opinions, we would like to suggest that there should be subject development that is connected to careers or job searching for senior students, and additional research of practical educational methods are also needed.
The need for interoperability at the national level was highlighted in Korea, leading to a consensus on the importance of establishing national standards that align with international technological ...standards and reflect contemporary needs. This article aims to share insights into the background of the recent national health data standardization policy, the activities of the Health Data Standardization Taskforce, and the future direction of health data standardization in Korea.
To ensure health data interoperability, the Health Data Standardization Taskforce was jointly organized by the public and private sectors in December 2022. The taskforce operated three working groups. It reviewed international trends in interoperability standardization, assessed the current status of health data standardization, discussed its vision, mission, and strategies, engaged in short-term standardization activities, and established a governance system for standardization.
On September 15, 2023, the notice of "Health Data Terminology and Transmission Standards" in Korea was thoroughly revised to improve the exchange of health information between information systems and ensure interoperability. This notice includes the Korea Core Data for Interoperability (KR CDI) and the Korea Core Data Transmission Standard (HL7 FHIR KR Core), which are outcomes of the taskforce's efforts. Additionally, to reinforce the standardized governance system, the Health-Data Standardization Promotion Committee was established.
Active interest and support from medical informatics experts are needed for the development and widespread adoption of health data standards in Korea.
As the number of cases of damage caused by malicious apps increases, accurate detection is required through various detection conditions, not just detection using simple techniques. In this paper, we ...propose a knowledge-based machine learning method using authority information and adding its usage counting features. This method is classifying training apps and malicious apps through machine learning using permission features in manifest.xml of Android apps. As a result of the experiment, accuracy, recall, precision, F1 score are 99.01%, 97.70%, 100.0%, 99.01%, respectively. Since Recall is higher than other indicators, it accurately predicts malicious apps as malicious. In other words, the proposed system is effective in preventing the distribution of malicious apps.
Although various fabrication methods for metal–oxide nanostructures have been well developed for enlarged surface area, numerous efforts to further enhance the effective surface area for their ...chemical sensor applications are still being studied. Herein, a high‐power laser is irradiated on the existing metal–oxide nanostructures to expose the hidden inner surface of the nanostructures for full participation in the surface gas‐sensing reactions, resulting in extraordinary gas‐sensing performance. In addition, noble metal catalyst decoration at both the inner and outer surfaces of the nanostructures records extremely high gas response and selectivity to volatile organic compounds. The numerical simulation and experimental verification of the effects of high‐power laser irradiation for morphological evolution of the metal–oxide nanostructures can provide a new perspective toward the time‐efficient development of nanostructure‐based electronic devices.
Abstract
This study describes the Korea Meteorological Administration/National Institute of Meteorological Sciences (KMA/NIMS) Atmospheric Research Aircraft (NARA) and its observational data archive. ...NARA has been performing annual observation flights, which are aimed at reducing the uncertainty of atmospheric observations in the observation data gap area around the Korean peninsula, since January 2018. An online system has also been constructed to provide data management, transmission, quality control and simple visualization. The mission strategy of NARA is subdivided into four individual units, namely observations of severe weather (SW), climate monitoring (CM), environmental monitoring (EM) and cloud physics and weather modification experiments (CP). As of December 2020, NARA has been launched operationally for 325 flights (corresponding to 9.02 flights per month), typically over the West Sea, mid‐inland areas (34.4% and 25.4%, respectively), and below an altitude of 3 km (51.9%). Results of intercomparison tests confirmed that NARA measurements have reasonable offsets (<0.9%) to each other in terms of pressure and temperature. Moreover, the monthly average temperature profile in the East Sea area showed a seasonal variation was detected in monthly variation. From these results, it is evident that NARA data will contribute significantly to enhancing the level of scientific understanding of atmospheric observations and the applications (i.e. long‐term study) thereof as the amount of data accumulated increases.
Photo(electro)catalysis methods have drawn significant attention for efficient, energy‐saving, and environmental‐friendly organic contaminant degradation in wastewater. However, conventional ...oxide‐based powder photocatalysts are limited to UV‐light absorption and are unfavorable in the subsequent postseparation process. In this paper, a large‐area crystalline‐semiconductor nitride membrane with a distinct nanoporous surface is fabricated, which can be scaled up to a full wafer and easily retrieved after photodegradation. The unique nanoporous surface enhances broadband light absorption, provides abundant reactive sites, and promotes the dye‐molecule reaction with adsorbed hydroxyl radicals on the surface. The superior electric contact between the nickel bottom layer and nitride membrane facilitates swift charge carrier transportation. In laboratory tests, the nanostructure membrane can degrade 93% of the dye in 6 h under illumination with a small applied bias (0.5 V vs Ag/AgCl). Furthermore, a 2 inch diameter wafer‐scale membrane is deployed in a rooftop test under natural sunlight. The membrane operates stably for seven cycles (over 50 h) with an outstanding dye degradation efficiency (>92%) and satisfied average total organic carbon removal rate (≈50%) in each cycle. This demonstration thus opens the pathway toward the production of nanostructured semiconductor layers for large‐scale and practical wastewater treatment using natural sunlight.
A nitride semiconductor nanostructured membrane is fabricated for a solar‐driven dye degradation utility. The reusable wafer‐scale membrane operates stably at outdoor with an outstanding dye degradation efficiency of >92%, providing satisfied and repeatable total organic carbon removal rate of ≈50%. The pathway for practical wastewater treatment using natural sunlight is thus demonstrated.
GaN vertical FinFETs on a bulk GaN substrate were fabricated with various fin widths and 400 ns pulsed I-V measurements were performed to investigate their self-heating and DC-RF dispersion. With ...low-temperature post-gate processes including Ar plasma-enhanced Ohmic contact, a high drain current density (>175 kA cm -2 ) and a low gate leakage (<1 × 10 -7 kA cm -2 ) could be achieved simultaneously. When normalized by the active fin area, the specific on-resistance was 0.030mΩcm 2 at the drain on-current of 119 kA cm -2 for the 300nm fin-width single-finger device. A 25-finger device with the same fin width and fin-to-fin pitch of 3 μm showed the on-resistance of 0.043mΩcm 2 (0.43mΩcm 2 when normalized by the total device area of 6000 μm2), which was one of the lowest values reported. Low DC-RF dispersion was observed for the devices more than 2.5mm away from the wafer edge. This study also reports that more influence of self-heating was observed as the fin width scaled down or the number of fingers increased.
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