• Journal of Broadcast Engineering
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• v.27 no.1
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• pp.91-103
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• 2022

Determination of sound source characteristics such as: sound volume, direction and distance to the source is one of the important techniques for unmanned systems like autonomous vehicles, robot systems and AI speakers. There are multiple methods of determining the direction and distance to the sound source, e.g., using a radar, a rider, an ultrasonic wave and a RF signal with a sound. These methods require the transmission of signals and cannot accurately identify sound sources generated in the obstructed region due to obstacles. In this paper, we have implemented and evaluated a method of detecting and identifying the sound in the audible frequency band by a method of recognizing the volume, direction, and distance to the sound source that is generated in the periphery including the invisible region. A cross-shaped based sound source recognition algorithm, which is mainly used for identifying a sound source, can measure the volume and locate the direction of the sound source, but the method has a problem with "blind spots". In addition, a serious limitation for this type of algorithm is lack of capability to determine the distance to the sound source. In order to overcome the limitations of this existing method, we propose a QRAS-based algorithm that uses rectangular-shaped technology. This method can determine the volume, direction, and distance to the sound source, which is an improvement over the cross-shaped based algorithm. The QRAS-based algorithm for the OSSD uses 6 AITDs derived from four microphones which are deployed in a rectangular-shaped configuration. The QRAS-based algorithm can solve existing problems of the cross-shaped based algorithms like blind spots, and it can determine the distance to the sound source. Experiments have demonstrated that the proposed QRAS-based algorithm for OSSD can reliably determine sound volume along with direction and distance to the sound source, which avoiding blind spots.

• 한국노년학
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• v.30 no.4
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• pp.1281-1292
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• 2010

This study was performed to identify older adults' self-reported difficulties in understanding and utilizing health information and their relationships with health status and to investigate the differences between age groups and among education levels. Data were collected from July 1 to August 31 in 2007 from older adults in senior centers located in Daegu, Kyungpook, and Busan area. A total of 103 subjects participated in the study. The level of understanding health information in older adults was 50 on average (possible score 15-75). The most difficult items to understand were patient educational materials, written information provided by health care providers, and medical forms. The lower level of difficulty in utilizing health information was associated with better physical and mental health status. There were differences in their self-reported difficulties between the young-old and the old-old as well as among different education levels. Health care providers may need to tailor educational materials and medical forms to the cognitive ability of older adults under the consideration of their age and education levels.

• Smart Media Journal
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• v.12 no.10
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• pp.71-84
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• 2023

Paralichthys olivaceus accounts for a large proportion, accounting for more than half of Korea's aquaculture industry. However, about 25-30% of the total breeding volume throughout the year occurs due to diseases, which has a very bad impact on the economic feasibility of fish farms. For the economic growth of Paralichthys olivaceus farms, it is necessary to quickly and accurately diagnose disease symptoms by automating the diagnosis of Paralichthys olivaceus diseases. In this study, we create training data using innovative data collection methods, refining data algorithms, and techniques for partitioning dataset, and compare the Paralichthys olivaceus disease symptom detection performance of four object detection deep learning models(such as YOLOv8, Swin, Vitdet, MvitV2). The experimental findings indicate that the YOLOv8 model demonstrates superiority in terms of average detection rate (mAP) and Estimated Time of Arrival (ETA). If the performance of the AI model proposed in this study is verified, Paralichthys olivaceus farms can diagnose disease symptoms in real time, and it is expected that the productivity of the farm will be greatly improved by rapid preventive measures according to the diagnosis results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.61-81
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• 2024

eCall system assists traffic accident victims by connecting emergency rescue institutions with accurate accident information, helping them to identify the on-site situation in the event of a traffic accident. The purpose of this paper is to develop a Korean eCall system that reflects the requirements of domestic emergency rescue institutions and to analyze the expected effects through an integrated demonstration. The results of an integrated demonstration indicated that the communication success rate between the eCall IVS and the call center was 99.25%, and the average location information error was 1.2 m. In particular, it has been confirmed that the average location information error is less than 21.6 meters, as assessed by the Korea Communications Commission when evaluating the accuracy of domestic emergency rescue location information. When the eCall system was introduced, it was confirmed that the time from traffic accidents to hospital arrival could be shortened by 3 m 38 s for highways and 1 m 22 s for general roads. By it to traffic deaths from 2005 to 2022, it was analyzed that the number of fatalities decreased by 82,662, resulting in a reduction of approximately social costs.

• Korean Journal of Cognitive Science
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• v.34 no.4
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• pp.259-275
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• 2023

The aim of this study was to investigate font change blindness based on text difficulty in the "Moving Window Task", as originally introduced by McConkie and Rayner(1975). During the reading process where the moving window was applied, different target words in terms of font style compared to the text were presented. As participants' gaze reached the position of the target word, the font of the target word was changed to match the text font. The font of the target word before the change was either sans-serif when the text font was serif, or serif when the text font was sans-serif. After completing the reading task, more than half of the participants(62.5%) reported not detecting the font change. Observation of eye movements at the target word positions revealed that when understanding the content within the text was difficult, there was an increase in the number of regressions, an extended gaze duration, and a reduction in saccade length. Specifically, the increase in the number of regressions was evident only when the text font was serif, in other words, when the font of the target word shifted from sans-serif to serif. These results suggest that sensory interference unrelated to content understanding is not easily detected during reading. However, the possibility of detection increases when comprehension of the content becomes challenging. Furthermore, this exceptional detection possibility implies that it may be higher when the text font is serif compared to when it is sans-serif.

• The Journal of Bigdata
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• v.8 no.2
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• pp.1-13
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• 2023

Current analysis of air passengers mainly relies on statistical methods, but there are limitations in analyzing detailed aspects such as travel routes, number of regional passengers and airport access times. However, with the advancement of big data technology and revised three data acts, big data-based transportation analysis has become more active. Mobile communication data, which can precisely track the location of mobile phone terminals, can serve as valuable analytical data for transportation analysis. In this paper, we propose a air passenger Origin/Destination (O/D) extraction algorithm based on mobile communication data that overcomes the limitations of existing air transportation user analysis methods. The algorithm involves setting airport signal detection zones at each airport and extracting air passenger based on their base station connection history within these zones. By analyzing the base station connection data along the passenger's origin-destination paths, we estimate the entire travel route. For this paper, we extracted O/D information for both domestic and international air passengers at all domestic airports from January 2019 to December 2020. To compensate for errors caused by mobile communication service provider market shares, we applied a adjustment to correct the travel volume at a nationwide citizen level. Furthermore correlation analysis was performed on O/D data and aviation statistics data for air traffic users based on mobile communication data to verify the extracted data. Through this, there is a difference in the total amount (4.1 for domestic and 4.6 for international), but the correlation is high at 0.99, which is judged to be useful. The proposed algorithm in this paper enables a comprehensive and detailed analysis of air transportation users' travel behavior, regional/age group ratios, and can be utilized in various fields such as formulating airport-related policies and conducting regional market analysis.

• Journal of Internet of Things and Convergence
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• v.10 no.4
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• pp.9-19
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• 2024

In this paper, a real-time public transportation monitoring system is proposed. The proposed system was implemented by developing a public transportation app and utilizing optical sensors, pressure sensors, and an object detection algorithm. Additionally, a bus model was created to verify the system's functionality. The proposed real-time public transportation monitoring system has three key features. First, the app can monitor congestion levels within public transportation by detecting seat occupancy and the total number of passengers based on changes in optical and pressure sensor readings. Second, to prevent errors in the optical sensor that can occur when multiple passengers board or disembark simultaneously, we explored the possibility of using the YOLO object detection algorithm to verify the number of passengers through CCTV footage. Third, convenience is enhanced by displaying occupied seats in different colors on a separate screen. The system also allows users to check their current location, available public transportation options, and remaining time until arrival. Therefore, the proposed system is expected to offer greater convenience to public transportation users.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.74-83
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• 2011

The high-pass transportation information system directly collects section information by using probe cars and therefore can offer more reliable information to drivers. However, because the running condition and features of probe cars and statistical processing methods affect the reliability of the information and particularly because the section travel time is greatly influenced by whether there has been delay by signals on urban roads or not, there can be much deviation among the collected individual probe data. Accordingly, researches in multilateral directions are necessary in order to enhance the credibility of the section information. Yet, the precedent studies related to high-pass information provision have been conducted on the highway sections with the feature of continuous flow, which has a limit to be applied to the urban roads with the transportational feature of an interrupted flow. Therefore, this research aims at analyzing the features of high-pass transportation data on urban roads and finding a proper processing method. When the characteristics of the high-pass data on urban roads collected from RSE were analyzed by using a time-space diagram, the collected data was proved to have a certain pattern according to the arriving cars' waiting for signals with the period of the signaling cycle of the finish node. Moreover, the number of waiting for signals and the time of waiting caused the deviation in the collected data, and it was bigger in traffic jam. The analysis result showed that it was because the increased number of waiting for signals in traffic jam caused the deviation to be offset partially. The analysis result shows that it is appropriate to use the mean of this collected data of high-pass on urban roads as its representative value to reflect the transportational features by waiting for signals, and the standard of judgment of delay and congestion needs to be changed depending on the features of signals and roads. The results of this research are expected to be the foundation stone to improve the reliability of high-pass information on urban roads.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.243-248
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• 2010

Two suspicious events, which were claimed as underground nuclear tests by North Korea, were detected in the northern Korean Peninsula on October 9, 2006 and May 25, 2009. The KIGAM and Korea-China Joint seismic stations are distributed uniformly along the boundaries between North Korea and adjacent countries. In this study, the data from broadband stations with the distance of 200 to 550 km from the test site are used to analyze and compare two nuclear tests of North Korea. By comparing the time differences of the Pn-wave arrival times of 1st and 2nd tests at multiple stations, the relative locations of two test sites could be calculated precisely. From the geometrical calculation with the velocity of Pn wave $V_{Pn}$ = 8 km/s, the 2nd test site is estimated to move in the WNW direction from 1st one with the distance of 2 km. Body wave magnitude, mb of the 2nd test, which was announced officially as the network average of 4.5, varies widely with the directional location of stations from 4.1 to 5.2. The magnitude obtained from Lg wave, $m_b$(Lg), shows less variation between 4.3 to 4.7 with the average of 4.6. The moving-window spectra of time traces of 1st and 2nd tests show very similar pattern with different scale level. In addition, the corner frequencies of P wave of 1st and 2nd tests at each station show no or negligible difference. This indicates the burial depths of two tests might be very similar. The relative yield amount of the 2nd test is estimated 8 times larger than that of the 1st from the weighted average of ground-velocity amplitude ratios.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.374-380
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• 2017

In this study, we analyzed the situation of the 119 emergency medical service zone of H town, countryside of Y city from January 1st, 2015 to December 31st, 2016 and then, on the basis of this analysis, we investigated the present condition of the patient-transportation service of the 119 emergency medical service to provide the basic data in order for patients to use the emergency medical service more efficiently. We analyzed the data with SPSS 21.0 using frequency analysis and, after positioning the virtual 119 emergency medical service, we analyzed the data of the transportation time and transportation distance by using GIS. The results of this study show that the use of the 119 emergency medical service for people over 65 years old represents approximately 57% of the total number of patients transported, The average distance and time of the real moving reaction are 6.41 km and 11.86 min, respectively. The distance and time from the pick-up location to the hospital are 18.24 km and 21.52 min, respectively. Given the present position of the 119 emergency medical service, the results of this analysis using GPS show that the (average) distance and time from the 119 emergency medical service to Jang * Ri town are 9.12 km and 12 min, and the (average) total distance and time to arrive at the hospital after the emergency medical service picks up the patient are 36.83 km and 62 min, respectively. In the case of the virtual emergency medical service, the total distance and time required to arrive at the hospital after the emergency medical service picks up the patient are 27.71km and 50min, respectively. The results of this study showed that the present position of the 119 emergency service does not provide the optimum distance and time from the patient's location to the hospital. Therefore, we consider that the repositioning of the 119 emergency medical center is necessary, in order to reduce the time required for the emergency medical service to move to the patient's location and then bring the patient to the hospital.