• International Journal of Safety
• /
• v.5 no.2
• /
• pp.18-23
• /
• 2006

Studies have claimed that ESE (Early Streamer Emission) air terminals offer a vastly increased zone of protection over that of traditional lightning rods (Franklin rods) by causing the emission of an upward streamer/leader: The upward streamer/leader will propagate towards the tip of the downward leader at an early stage in the attachment process.. This paper shows the results of a performance evaluation test of a particular type of the ESE air terminal (called "ElecHippo") with a simple rod tested at the Korea Electrotechnology Research Institute (KERI). The corona emission current of the ElecHippo made by Yong-Jin Enterprise Corp. has also been measured at the Occupational Safety & Health Research Institute (OSHRI). The results show that the ElecHippo meets the French standard of NFC 17-102-1995. The results also verify the ESE performance by measuring the ion emission current generated in the discharge electrode gap as a function of the capacitance and inductance of the equipped devices. Finally, we propose a new method for grounding the system to reduce the lightning damage by combining the ESE air terminal, the early discharge earth plate, the lightning strike recorder and the surge protection device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.211-212
• /
• 2007

There have three kinds of partial discharge diagnosis testing: online, offline and dismantled testing on high voltage rotating machine. Our lab testing is dismantled testing, taking off pieces into individual parts of stator coil of high voltage rotating machine in laboratory. We investigate internal discharge, slot discharge, corona discharge and normal state on pre-made stator winding by using spiral patch antenna sensor. In this lab test we compare the experimental results of our spiral patch antenna sensor and reference commercial HFCT sensor.

• Journal of the Korea Convergence Society
• /
• v.12 no.7
• /
• pp.1-6
• /
• 2021

Currently, virus infection such as Corona 19 has become commonplace, and interest in unmanned systems is increasing in the field for non-face-to-face ICT services. In this paper, the function and performance of remotely successfully controlling a store through video and audio using an IP PBX with a broadcasting function was verified through a test. And the fully unmanned system is not gaining credibility due to various technical problems, however the central control system is a very efficient and reliable system because the controller can directly control the customer while monitoring the access and the inside of the store through the video and audio. In the future, we plan to study a completely unmanned remote control system using A.I technology.

• The Korean Journal of Emergency Medical Services
• /
• v.25 no.1
• /
• pp.85-103
• /
• 2021

Purpose: This study measured the mental health levels of 119 paramedics, and identified the association of mental health levels with safety environments, personal protective equipment, and coronavirus risk awareness. Methods: A total of 119 out of 428 from Daegu and Gyeongbuk took part in this study. The statistical analysis methods were the t-test, ANOVA, Pearson's correlation analysis and multiple regression analysis. Results: In a multiple regression analysis, females (β=-.137, p=<.001) showed a higher relevance to negative mental health than males. The moderate satisfied (β=-.088, p=.014) and dissatisfied (β=-.147, p=.006) showed a higher relevance to negative mental health than higher satisfied. Moderate stress perception (β=-.199, p=<.001) and higher stress perception (β=-.414, p=<.001) showed a higher relevance to negative mental health than lower stress perception. Corona-virus risk awareness (β=-.050, p=.045) was related to negative mental health and safety environment (β=.136, p=<.001). Personal protective equipment (β=.147, p=<.001) were related to positive mental health. Conclusion: Conclusively, it is necessary to develop and implement high-quality intervention programs using significantly influencing variables to impact the mental health of 119 paramedics.

• Journal of radiological science and technology
• /
• v.44 no.6
• /
• pp.679-688
• /
• 2021

This study is a questionnaire about the lesson environment that radiation major students prefer in a non-face-to-face live online lesson environment for a total of 133 students, 65 second graders and 68 third graders who are enrolled in the department of radiology at a university located in the Seoul metropolitan area. And checked the satisfactory level by grade. The questionnaire consists of three categories: 1st real-time non-face-to-face lectures, 2nd professor lectures, and 3rd corona lectures. A total of 14 questions, with multiple choice and descriptive response methods. As an evaluation method, in the case of a multiple-choice question, the average was calculated using a 5-point Likert scale. As a result of conducting the independent sample T-test of the SPSS program, the response by grade was P > 0.05, and no significant result was shown by the contents of the questionnaire survey of the second grade. As for the lecture method of the department of radiology after the end of Covid-19 virus, it is better to promote face-to-face lessons in radiation training subjects and non-face-to-face real-time education in subjects centered on radiation theory.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.45 no.3
• /
• pp.139-149
• /
• 2022

Korea's Corona 19(COVID-19) quarantine, referred to as 'K-Quarantine', is a globally recognized quarantine system that has achieved both conflicting goals: health and economy. The quarantine system represented by 3T(Test-Trace-Treat) is not a method of blocking an area, but a method of screening and treating infected and non-infected persons. The screening center, one of the key elements of this screening treatment system, has evolved to suit the timing and situation of COVID-19, and has succeeded in initial response by conducting large-scale tests quickly and safely. By analyzing the evolution of screening centers that produced such significant results from a problem-solving point of view, it proved its meaning as a practical success case of creative problem-solving. In addition, the usefulness of TRIZ (Russian abbreviation of Theory of Solving Inventive Problem), a creative problem-solving theory, was confirmed through an analysis of actual verified cases of COVID-19 response. TRIZ is a problem-solving theory created by analyzing the regularity of invention patents, and is widely used not only in the technical field but also in the non-technical fields such as design, management, and education. The results of this study are expected to provide useful meaning and practical examples to researchers interested in system analysis and TRIZ application from a problem-solving perspective.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.42.3-42.3
• /
• 2019

We translate Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) ultraviolet (UV) multi-channel images into another UV single-channel image using a deep learning algorithm based on conditional generative adversarial networks (cGANs). The base input channel, which has the highest correlation coefficient (CC) between UV channels of AIA, is 193 Å. To complement this channel, we choose two channels, 1600 and 304 Å, which represent upper photosphere and chromosphere, respectively. Input channels for three models are single (193 Å), dual (193+1600 Å), and triple (193+1600+304 Å), respectively. Quantitative comparisons are made for test data sets. Main results from this study are as follows. First, the single model successfully produce other coronal channel images but less successful for chromospheric channel (304 Å) and much less successful for two photospheric channels (1600 and 1700 Å). Second, the dual model shows a noticeable improvement of the CC between the model outputs and Ground truths for 1700 Å. Third, the triple model can generate all other channel images with relatively high CCs larger than 0.89. Our results show a possibility that if three channels from photosphere, chromosphere, and corona are selected, other multi-channel images could be generated by deep learning. We expect that this investigation will be a complementary tool to choose a few UV channels for future solar small and/or deep space missions.

• Restorative Dentistry and Endodontics
• /
• v.47 no.3
• /
• pp.28.1-28.12
• /
• 2022

Objectives: Metalloproteinase-inhibiting agents, such as chitosan, can prevent collagen degradation in demineralized dental substrates, thereby improving the adhesive interface. This study evaluated the bond strength (BS) and chemical and morphological characterization of the adhesive interface after applying chitosan solution to demineralized dentin. Materials and Methods: The 80 third molars were selected. Forty teeth underwent caries induction using the pH cycling method. The teeth were divided according to the treatment: distilled water (control) and 2.5% chitosan solution. The surfaces were restored using adhesive and composite resins. Half of the specimens in each group were aged, and the other half underwent immediate analyses. The teeth were sectioned and underwent the microtensile bond strength test (µTBS), and chemical and morphological analyses using energy-dispersive spectroscopy and scanning electron microscopy, respectively. Data analysis was performed using 3-way analysis of variance. Results: For µTBS, sound dentin was superior to demineralized dentin (p < 0.001), chitosan-treated specimens had higher bond strength than the untreated ones (p < 0.001), and those that underwent immediate analysis had higher values than the aged specimens (p = 0.019). No significant differences were observed in the chemical or morphological compositions. Conclusions: Chitosan treatment improved bond strength both immediately and after aging, even in demineralized dentin.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.85.1-85.1
• /
• 2017

We develop a coronagraph to measure the coronal electron density, temperature, and speed by observing the linearly polarized brightness of solar corona with 4 different wavelengths. Through the total solar eclipse on 21 August 2017, we test an operating software of a prototype coronagraph working with two sub-systems of two motorized filter wheels and a CCD camera that are controlled by a portable embedded computer. A Core Flight System (CFS) is a reusable software framework and set of reusable software applications which take advantage of a rich heritage of successful space mission of NASA. We use the CFS software framework to develop the operating software that can control the two sub-systems asynchronously in an observation scenario and communicate with a remote computer about commands, housekeeping data through Ethernet. The software works successfully and obtains about 160 images of 12 filter sets (4 bandpass filters and 3 polarization angles) during the total phase of the total solar eclipse. For the future, we can improve the software reliability by testing the software with a sufficient number of test cases using a testing framework COSMOS. The software will be integrated into the coronagraph for balloon-borne experiments in 2019.

• International Journal of Knowledge Content Development & Technology
• /
• v.12 no.4
• /
• pp.25-39
• /
• 2022

Perceptions of Library and Information (LI) professionals in Nigeria and the impact of COVID-19 on libraries, librarians and library services, were studied. The significance of demographic factors on LI professionals' perception of COVID-19 and its impact on libraries was tested. Descriptive survey design and Purpose sampling technique were adopted. LIS professionals in Nigeria constituted the population, and an online questionnaire designed by the researchers through Microsoft Forms was used. Descriptive analysis of respondents' demographic data and their covid-19 perception were presented in frequencies and percentages using tables while multivariate regression technique was used to test the significance of relationship between variables at P < 0.05. Findings revealed that many (61.4%) of the respondents agreed that COVID-19 is real but have personal reservations. However, 47.5% indicated that COVID-19 is a scientific invention. On the impacts of COVID-19 on libraries, the study found that COVID-19 is a game changer that will enhance the creation of new services by libraries, cause the reconfiguration of library space for safe operations in post-COVID, establishment of new rules and regulations, and more reliance on e-resources. On the test of association, educational qualification of respondents had a significant impact on respondents' perceptions that COVID-19 will reduce the use of library print resources (P-value = 0.005, B: 0.38, [95% CI: 0.115 - 0.646]) and that library will create new services to address the changes caused by COVID-19. Also, educational qualification of respondents significantly influenced respondents' perception that COVID-19 is real. The study recommends that libraries should take advantage of the season to innovate, and that public health institutions should continually educate people on corona virus to disabuse people's mind of conspiracy theories.