• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.793-799
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• 2018

The CCD camera is easily deteriorated by radiation, and an integrated camera using an image pickup tube is used in a high radiation area. We implemented a radiation camera system which is divided into a camera head using radiation-resistant electronic components and a remote control using weak radiation-resistant electronic components such as TR, IC, etc. According to the experimental results, the first damage of the electronic parts was IC for horizontal and vertical sync generation, and it was confirmed that if the radiation of $2{\times}10^5{\sim}10^6rad$ is accumulated, the normal function is lost. In addition, the signal transmission cable for remoteization has added an input/output buffer circuit and reduced the closed loop area of the shield and the cable to eliminate signal loss correction and noise. Therefore, it is expected that the maintenance cost will be greatly reduced and practical because only the camera head part can be used instead of replacing the entire system.

• Current Optics and Photonics
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• v.5 no.2
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• pp.147-154
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• 2021

Microfluidic chip technology is a research focus in biology, chemistry, and medicine, for example. However, microfluidic chips are rarely applied in imaging, especially in ghost imaging. Thus in this work we propose a ghost-imaging system, in which we deploy a novel microfluidic chip modulator (MCM) constructed of double-layer zigzag micro pipelines. While in traditional situations a spatial light modulator (SLM) and supporting computers are required, we can get rid of active modulation devices and computers with this proposed scheme. The corresponding simulation analysis verifies good feasibility of the scheme, which can ensure the quality of data transmission and achieve convenient, fast ghost imaging passively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.4
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• pp.405-411
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• 2020

Objectives: The objectives of this study were to investigate whether airborne fibers were released to the outside air from the asbestos removal area in buildings, and to confirm the existence of asbestos fibers in samples using transmission electron microscopy(TEM). Methods: A total of 1,295 samples was collected from inside and outside 155 asbestos removal areas. To investigate the release of asbestos fibers from the removal area, samples were collected at three locations, such as an entrance to change room, an exit of negative pressure unit(NPU) and perimeter areas. Samples were also collected in the removal area prior to and after removal activity. All samples were analyzed by phase contrast microscopy(PCM) and one-tenth of the samples was analyzed using TEM to discriminate asbestos fibers. Results: During the asbestos removal activity, 27(4.1%) of 662 samples collected outside the removal area showed airborne fiber concentrations equal to or in excess of 0.01 f/cc, the permissible emission standard of the Korean Ministry of Environment. Further, 111 samples were analyzed using TEM. The distribution of asbestos fiber concentrations was log-normal. It was found that 51 of 111 samples(46%) contained asbestos fibers. Conclusions: There is a potential risk of asbestos exposure among neighbors and the public outside the asbestos removal areas. It is recommended that the asbestos removal work be conducted strictly following the specifications required by government and/or professional organizations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.195-215
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• 2021

Multipath Transport Control Protocol (MPTCP) is a transport layer protocol that enables multiple TCP connections across various paths. Due to path heterogeneity, it incurs more energy in a multipath wireless network. Recent work presents a set of approaches described in the literature to support systems for energy consumption in terms of their performance, objectives and address issues based on their design goals. The existing solutions mainly focused on the primary system model but did not discourse the overall system performance. Therefore, this paper capitalized a novel stochastically multipath scheduling scheme for data and path capacity variations. The scheduling problem formulated over MPTCP as a stochastic optimization, whose objective is to maximize the average throughput, avoid network congestion, and makes the system more stable with greater energy efficiency. To design an online algorithm that solves the formulated problem over the time slots by considering its mindrift-plus penalty form. The proposed solution was examined under extensive simulations to evaluate the anticipated stochastic optimized MPTCP (so-MPTCP) outcome and compared it with the base MPTCP and the energy-efficient MPTCP (eMPTCP) protocols. Simulation results justify the proposed algorithm's credibility by achieving remarkable improvements, higher throughput, reduced energy costs, and lower-end to end delay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.515-522
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• 2021

In this paper, we present and analyze a method of applying a machine learning to ultrasonic test signals for constant monitoring of the welding faults in a tubular steel tower. For the machine learning, feature selection based on genetic algorithm and fault signal classification using a support vector machine have been used. In the feature selection, the peak value, histogram lower bound, and normal negative log-likelihood from 30 features are selected. Those features clearly indicate the difference of signals according to the depth of faults. In addition, as a result of applying the selected features to the support vector machine, it has been possible to perfectly distinguish between the regions with and without faults. Hence, it is expected that the results of this study will be useful in the development of an early detection system for fault growth based on ultrasonic signals and in the energy transmission related industries in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.143-148
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• 2021

A systematic study of Bloch surface wave (BSW), which is created by guided mode resonance (GMR) of dielectric multilayer structures with a grating profile, is presented to analyze the sensing performance of bio-sensors. The effect of structural parameters on optical behavior is evaluated by using Babinet's principle and modal transmission-line theory. The sensitivity of designed bio-sensors is proportional to the grating constant at wavelength spectrum, and inversely proportional to the normal wave vector of incident electromagnetic wave at angular spectrum. Numerical results for two devices with SiO/SiO₂ and TiO₂/SiO₂ multilayer dielectric stacks are presented, showing that BSW can be exploited for the realization of efficient diffraction-based bio-sensors from infrared to visible-band range.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1183-1194
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• 2021

Traditionally, electric power systems have been known as the centralized structures, which is organized into placing customers at the end of the supply chain. However, recent decades have witnessed the emergence of distributed energy resources(:DERs) such as rooftop solar, farming PV system, small wind turbines, battery energy storage systems and smart home appliances. With the emergence of distributed energy resources, the role of distributed system operators(:DSOs) will expand. The increasing penetration of DERs could lead to a less predictable and reverse flow of power in the system, which can affect the traditional planning and operation of distribution and transmission networks. This raises the need for a change in the role of the DSOs that have conventionally planned, maintained and managed networks and supply outages. The objective of this research is to designed the future distribution operation system with multi-DERs and the proposed distribution system model is implemented by hardware-in-the-loop simulation(HILS). The test results show the normal operation domain and reduction of distribution line loss.

• Asia-Pacific Journal of Business
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• v.12 no.1
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• pp.71-86
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• 2021

Purpose - This study examines the awareness regarding the symptoms of COVID-19 exposures and safety distances strategies whether they were useful to resile the businesses a mid of the pandemic. Besides exploring the awareness and safety distances, the effectiveness of offering free use of protective equipment (mask, hand sanitizer, frequent hand washing, etc.) to the customers for visiting the business centers was also examined. Design/methodology/approach - This study collected 264 survey data in Bangladesh which is one of the most densely populated country and very vulnerable for COVID-19 due to its socio-economic condition. The multiple regression analysis is used to analyze the data. Findings - The findings of the study indicate that the awareness about the symptoms of virus exposures (cough, fever, diarrhea, and weakness) has significant affirmative effects to enhance the public movement for business purposes with the lower possibility to be affected by the virus. The study also indicates that safety distances and protective equipment can mediate the significant positive relationship between the awareness of the disease and the businesses' resilient capacity. Research implications or Originality - COVID-19, as an apprehensive health issue in the current world, has sharpened the uncertainty of the businesses. One essential technique as lockdown, has been followed by almost every country to protect the transmission of the virus even though the scholars criticized it due to the substantial adverse effects on the country's economy. Under this circumstances, this study provides implications to the relevant businesses by assessing the nexus between the safety distances and the proper uses of protective equipment with the business resilient.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.79-86
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• 2019

Drama, as an artistic stage performance style of traditional life style, has built a bridge of communication between the two nationalities in China and Korea. However, the different performance procedures and cultural backgrounds of different countries make the theatrical arts of China and Korea present different stage manifestations. The dissemination and influence of the Chinese drama and in Korea are mainly studied in this paper. By using the methods of work analysis and text analysis, this paper further explores the evolution history of drama communication, the influence of Chinese drama on Korea, which embodies the cultural transmission, and explores the influence of communication and the acceptance degree of the audience. It has the significance and value of research, at the same time, it promotes the long-term development of national culture.

• Journal of Information Science Theory and Practice
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• v.12 no.2
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• pp.49-63
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• 2024

Information behavior played a significant role in minimizing the risks of the COVID-19 pandemic. When faced with such a situation, an individual needs information for decision-making and in order to determine the best course of action relating to their health. This study aims to explore information behavior during each phase of the COVID-19 pandemic in Indonesia, which is known for its close-knit collective culture. A sensemaking approach is used, which emphasizes the process individuals go through to understand their situation and give meaning to the information they are getting from their environment. Data was collected through in-depth interviews with 10 participants to obtain a description of their information behaviors during the pandemic. Data analysis was carried out using open, axial, and selective coding. We propose a sensemaking-based information behavior strategy framework for mitigating risk and reducing ongoing health crises. Changes in information behavior strategies, including search, prevention, and restriction of information exposure, were random at the beginning of the pandemic, but became more regular in later phases. This was influenced by the "knowledge gap fulfillment" and "use of local knowledge" among the participants throughout the pandemic. In conclusion, the participants developed a sensemaking process including an understanding of the pandemic situation and the risks that they faced. They used a number of information behavior strategies to prevent transmission, and their perception of the risks changed across the course of the pandemic, up til the situation began to be considered back to normal again in Indonesia.