• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.30-37
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• 2021

Various devices are connected to the Internet, and attacks using the Internet are occurring. Among such attacks, there are attacks that use malicious URLs to make users access to wrong phishing sites or distribute malicious viruses. Therefore, how to detect such malicious URL attacks is one of the important security issues. Among recent deep learning technologies, neural networks are showing good performance in image recognition, speech recognition, and pattern recognition. This neural network can be applied to research that analyzes and detects patterns of malicious URL characteristics. In this paper, performance analysis according to various parameters was performed on a method of detecting malicious URLs using neural networks. In this paper, malicious URL detection performance was analyzed while changing the activation function, learning rate, and neural network structure. The experimental data was crawled by Alexa top 1 million and Whois to build the data, and the machine learning library used TensorFlow. As a result of the experiment, when the number of layers is 4, the learning rate is 0.005, and the number of nodes in each layer is 100, the accuracy of 97.8% and the f1 score of 92.94% are obtained.

• The Journal of the Acoustical Society of Korea
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• v.40 no.4
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• pp.297-303
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• 2021

When sound waves propagate over long distances in shallow water, measured transmission loss is greater than predicted one using underwater acoustic model with the Rayleigh reflection model due to inhomogeneity of the bottom. Accordingly, the US Navy predicts sound wave propagation by applying the empirical formula-based High Frequency Bottom Loss (HFBL) model. In this study, the measurement and analysis of transmission loss was conducted using mid-frequency (2.3 kHz, 3 kHz) in the shallow water of the East Sea in summer. BELLHOP eigenray tracing output shows that only sound waves with lower grazing angle than the critical angle propagate long distances for several kilometers or more, and the difference between the predicted transmission loss based on the Rayleigh reflection model and the measured transmission loss tend to increase along the propagation range. By comparing the Rayleigh reflection model and the HFBL model at the high grazing angle region, the bottom province, the input value of the HFBL model, is estimated and BELLHOP transmission loss with HFBL model is compared to measured transmission loss. As a result, it agrees well with the measurements of transmission loss.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.195-205
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• 2021

Purpose: The ultraviolet reflectance and transmittance of coastal building materials are one of the important factors of ultraviolet radiation in and out of coastal building. In this research, the ultraviolet spectral reflectance of many kinds of building materials was measured. Also, the relationships with the lightness, roughness, and chromaticity, which are surface characteristics, were reviewed and suggested. Method: In this study, according to the CIE classification, the ultraviolet region was defined as short-wavelength region UV-C(10nm~280nm), medium-wavelength region UV-B (280-315 nm), and long-wavelength region UV-A (315-400nm), and the visible light region was defined as (400nm~780nm). Spectrophotometer was used to continuously measure the reflectance from the ultraviolet region to the visible light region. Results: From the measurement results, the ultraviolet reflectance on Wood was shown to be about Visible 55-68%, UV-A^* 7-12%, and UV-B 4-5%. Wall tiles are about Visible18-40%, UV-A^* 8-20%, and UV-B^* 7-8%. That on concrete was shown to be about Visible 37%, UV-A^* 28%, and UV-B^*19%. Conclusion: The ultraviolet reflectance can be estimated by visible reflectance. Also, it is important to select a variety of materials according to the application when blocking UV.

• The Korean Journal of Archival Studies
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• no.69
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• pp.129-152
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• 2021

With the enactment and enforcement of the 「Public Records and Archives Act」, the Tottori Prefectural Archives newly enacted the "Records Management Ordinance" through a comprehensive review of the previous archive function. In accordance with this ordinance, which came into effect in April 2012, Tottori Prefecture expanded the records management institutions (Public Security Committee and Police Headquarters, etc.) A series of archive systems were improved, such as the expansion and reinforcement of the authority to appraisal and select. In addition, the Tottori Prefectural Archives went further and implemented the "Ordinance on the Preservation of Historical Documents, etc." from April 2017. Through this, the municipalities unit basic local government's record management support work was set as a unique function of the local archive, and a linkage and cooperation system was established for the preservation of private records of the prefecture area as well as the basic local area together with cultural heritage institutions such as museums and libraries. As a reference case that continuously guarantees the performance of various activities based on the mission and vision of the local archives in Korea that aim for 'autonomy of records' on the poor archival culture soil, it is worth paying attention to the case of continuous record management reform of the Tottori Prefectural Archives through the enactment of the original role and function of the archive.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.77-89
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• 2020

Nowadays, urban townhouses are being developed in various forms according to the characteristics of different regions in consideration of the trends of the housing market. Misperceiving the needs of consumers or their characteristics as a house for living, however, they often end up becoming products that are not suitable for urban life or degraded on account of reckless regional development. It is so unfortunate that such trial and error keeps being repeated. Urban townhouses are advantageous because there is no such problem as either invasion of privacy or noise from neighbors, and it is possible to have one's own garden and enlarged parking space, obtain quality of grounding, and plan unique interior and exterior design. They are also equipped with the strengths of apartment houses as well, for example, the efficiency of joint control in crime and disaster prevention or security, architecture of diaphragm walls with the separation of gates, or the planning of common space like a central square or park. Therefore, there is a great chance that they can be developed as the types of urban housing. Accordingly, the purpose of this study is to establish the basic direction of developing housing products right as space for urban life and maximize the roles of urban townhouses. By understanding their spatial as well as functional elements as a house for living, this author aims to provide a guideline for housing product development to realize urban townhouses that can meet consumer needs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.94-101
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• 2021

According to the Facility Management System (FMS) operated by the Korea Authority of Land & Infrastructure Safety, it is expected that the number of aging facilities that have been in use for more than 30 years will increase rapidly to 13.9% in 2019 and 34.5% in 2929, and end up with a social problem. In addition, with the revision of "Common Application of Seismic Design Criteria" by the Ministry of Public Administration and Security in 2017, it is mandatory to re-evaluate all existing road facilities and if necessary seismic reinforcement should be done to minimize the magnitude of earthquake damage and perform normal road functions. The seismic performance management-decision support technology currently used in seismic performance management practice in Korea only determines the earthquake-resistance reinforcement priority based on the qualitative index value for the seismic performance of individual facilities. However with this practice, normal traffic functions cannot be guaranteed. A new seismic performance management decision support technology that can provide various judgment data required for decision making is needed to overcome these shortcomings and better perform seismic performance management from a road network perspective.

• Journal of Family Resource Management and Policy Review
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• v.26 no.2
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• pp.37-51
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• 2022

This study examines the relationship between flexible work and workers' work-life balance using data from the 23rd Korean Labor and Income Panel Study, with a focus on the impact of working from home (WFH) during the COVID-19 pandemic. As a result of the analysis, WFH was found to have a positive effect on the happiness of workers, satisfaction with family relationships, job satisfaction, organizational commitment, and job satisfaction related to job security for women. In addition, we looked at the changes in time use of WFH workers and non-WFH workers before and after COVID-19, with a particular focus on aspects such as time spent sleeping and on self-development, childcare, housework, exercise, and social gatherings. Compared to non-WFH workers, WFH workers increased the time spent on housework and childcare after COVID-19, with this trend more pronounced among women. The results of this study suggest that the effect of utilizing WFH may be halved for workers who have to take care of children and work at the same time, and that this effect may be greater for women. Therefore, it is necessary to strengthen social support measures so that WFH workers who face a work-life conflict due to childcare can maintain work productivity and realize a work-life balance, and to ensure that the flexible work arrangement should not be a medium that reinforces traditional gender roles. Active policy efforts will be required to make sure this happens.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.203-215
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• 2022

The study is to investigate research trends and knowledge structures in the Smart Farm field. To achieve the research purpose, keywords and the relationship among keywords were analyzed targeting 104 Korean academic journals related to the Smart Farm in KCI(Korea Citation Index), and topics were analyzed using the LDA Topic Modeling technique. As a result of the analysis, the main keywords in the Korean Smart Farm-related research field were 'environment', 'system', 'use', 'technology', 'cultivation', etc. The results of Degree, Betweenness, and Eigenvector Centrality were presented. There were 7 topics, such as 'Introduction analysis of Smart Farm', 'Eco-friendly Smart Farm and economic efficiency of Smart Farm', 'Smart Farm platform design', 'Smart Farm production optimization', 'Smart Farm ecosystem', 'Smart Farm system implementation', and 'Government policy for Smart Farm' in the results of Topic Modeling. This study will be expected to serve as basic data for policy development necessary to advance Korean Smart Farm research in the future by examining research trends related to Korean Smart Farm.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.126-132
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• 2022

Alkaline fuel cells using liquid fuels such as hydrazine and ammonia are gaining great attention as a clean and renewable energy solution possibly owing to advantages such as excellent energy density, simple structure, compact size in fuel container, and ease of storage and transportation. However, common shortcomings including cathode flooding, fuel crossover, side yield reactions, and fuel security and toxicity are still challenging issues. Real time monitoring of fuel concentrations integrated into a fuel cell device can help improving fuel cell performance via predicting any loss of fuels used at a cathode for efficient energy production. There have been extensive research efforts made on developing real-time sensing platforms for hydrazine and ammonia. Among these, recent advancements in electrochemical sensors offering high sensitivity and selectivity, easy fabrication, and fast monitoring capability for analysis of hydrazine and ammonia concentrations will be introduced. In particular, research trend on the integration of metallic and metal oxide nanoparticles and also their hybrids with carbon-based nanomaterials into electrochemical sensing platforms for improvement in sensitivity and selectivity will be highlighted.

• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.77-86
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• 2023

Ship detection is widely used in areas such as maritime security, maritime traffic, fisheries management, illegal fishing, and border control, and ship detection is important for rapid response and damage minimization as ship accident rates increase due to recent increases in international maritime traffic. Currently, according to a number of global and national regulations, ships must be equipped with automatic identification system (AIS), which provide information such as the location and speed of the ship periodically at regular intervals. However, most small vessels (less than 300 tons) are not obligated to install the transponder and may not be transmitted intentionally or accidentally. There is even a case of misuse of the ship'slocation information. Therefore, in this study, ship detection was performed using high-resolution optical satellite images that can periodically remotely detect a wide range and detectsmallships. However, optical images can cause false-alarm due to noise on the surface of the sea, such as waves, or factors indicating ship-like brightness, such as clouds and wakes. So, it is important to remove these factors to improve the accuracy of ship detection. In this study, false alarm wasreduced, and the accuracy ofship detection wasimproved by removing wake.As a ship detection method, ship detection was performed using machine learning-based random forest (RF), and convolutional neural network (CNN) techniquesthat have been widely used in object detection fieldsrecently, and ship detection results by the model were compared and analyzed. In addition, in this study, the results of RF and CNN were combined to improve the phenomenon of ship disconnection and the phenomenon of small detection. The ship detection results of thisstudy are significant in that they improved the limitations of each model while maintaining accuracy. In addition, if satellite images with improved spatial resolution are utilized in the future, it is expected that ship and wake simultaneous detection with higher accuracy will be performed.