• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.277-284
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• 2014

This paper describes the application method of bumper area defined in the ship domain theory and it is to identify risky sectors in VTS(Vessel Traffic Services) area. The final goal of this work is to develop early warning system providing the location information with high traffic risks in Mokpo VTS area and to prevent the human errors of VTS Officer(VTSO). The current goal of this paper is to find evaluation and detection method of risky sectors. The ratio between overlapped bumper area of each vessels and the summing area of a designated sector, Ratio to Evaluate Risk(RER) ${\gamma}$ is used as one of evaluation and detection parameter. The usability of overlapped bumper area is testified through three kinds of scenarios for various traffic situations. The marine traffic data used in the experiments is collected by AIS(Automatic Identification System) receiver and then compiled in the SQL(Structured Query Language) Server. Through the analysis of passing vessel's tracks within the boundary of Mokpo VTS area, the total of 11 sectors are identified as evaluation unit sector. As experiment results from risk evaluation for the 11 sectors, it is clearly known that the proposed method with RER ${\gamma}$ can provide the location information of high risky sectors which are need to keep traffic tracks of vessel movements and to maintain traffic monitoring by VTSO.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.644-662
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• 2023

There are still outbreaks of COVID-19 across the world. Ships increase the risk of worldwide transmission of the virus. Close contact tracing remains as an effective method of reducing the risk of virus transmission. Therefore, close contact tracing in ship environments becomes a research topic. Exposure Notifications API (Application Programming Interface) can be used to determine the encountered location points of close contacts on ships. Location points of close contact are estimated by the encountered location points. Risky areas in ships can be calculated based on the encountered location points. The tracking of close contacts is possible with Bluetooth technology without the Internet. The Bluetooth signal can be used to judge the proximity among detecting devices by using the feature that Bluetooth has a strong signal at close range. This Bluetooth feature makes it possible to trace close contacts in ship environments. In this paper, we propose a method for close contact tracing and showing the risky area in a ship environment by combining beacon and Exposure Notification API using Bluetooth technology. This method does not require an Internet connection for tracing close contacts and can protect the personal information of close contacts.

• Journal of Preventive Medicine and Public Health
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• v.45 no.3
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• pp.156-163
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• 2012

Objectives: It is necessary to examine groups carrying out sexually risky behavior because the prevalence of sexually transmitted diseases (STDs) is high among them. In this study, the prevalence of STDs among homosexuals and sexbuying men in South Korea was investigated, along with their sexual risk factors. Methods: Men who have sex with men (MSMs, n=108) were recruited in Seoul and Busan by applying the time location sampling method, while sex-buying men (n=118) were recruited from a john school in Gyeonggi province, the suburbs of Seoul. Dependent variables included past or present infection with syphilis, Chlamydia, gonorrhea, and human immunodeficiency virus. Independent variables included health behavior, social support, sexual behavior, and safe sex. Results: It was found that when the MSMs were non-drunk while having sexual intercourse (odds ratio [OR], 0.132), they showed a higher STD infection rate when they had a higher number of anal sex partners (OR, 5.872), rarely used condoms (OR, 1.980), had lower self-efficacy (OR, 0.229), and were more anxious about becoming infected with an STD (OR, 3.723). However, the men who paid for sex showed high STD infections when they had more sex partners (OR, 2.286) and lower education levels (OR, 3.028). Conclusions: STD infections among the two groups were high when they were engaged with many sex partners and not having protected sex. In other words, there was a gap in risky sex behavior within such groups, which was significantly related to the possibility of developing an STD. Therefore, the preventive intervention against STDs for these groups needs to be expanded to include management of sex behaviors.

• Journal of the Korean Institute of Rural Architecture
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• v.25 no.4
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• pp.17-24
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• 2023

This study is about the traditional house of Kim Myeong-Gwan, the founder of Gwangsan Kim clan(光山金氏) and the 30th grandson of Heunggwang, the 49th king of the Unified Silla Dynasty. He sought a place to take refuge due to a plot and built a house in Jeongeup, adjacent to Yeonsan or Nonsan, Chungcheong-do, which is the home of the Gwangsan Kim clan. The location of old houses was analyzed through Hyeongselon(形勢論) and hyeongguklong(形局論) of Pungsu theory. The results of fengshui analysis of the house through fengshui literature that was presumed to have been used at the time are as follows.The dragon(龍) shows an auspicious condition in which the dragon vein is well connected from its roots in the Honam vein to Guksabong Mountain on Josan Mountain, Bibongsan Mountain on Sojo Mountain, and Mt. Changhasan reaching Jusan Mountain. Hyeol(穴) is a type of Wahyeol(窩穴) and is a Hwalwa(濶窩). Hyeolseong(穴星) is a Jeongche-Hyeolseong(正體穴星) and is a Suseong Hyeol(水星穴). HyeolJung(穴證) and Hyeolgi(穴忌) have the conditions to create hyeol. As for Sa(砂), the height of Hyeonmu(玄武) is not that high, but the Jujak(朱雀) is relatively high, the left blue dragon(左靑龍) is complemented by the outer blue dragon(外靑龍), and the right white tiger(右白虎) does not sufficiently surround the house. To compensate for this, Bibosu trees(裨補樹) were planted at the time of the construction of the house. As for the Water element, it appears to be auspicious as it approaches the old house in the form of a curve, but it has the disadvantage of not sufficiently surrounding the house, so an artificial pond is dug as a Bibo Pungsu(裨補風水). Through this study, it was found that Pungsu was applied as an important consideration factore in selecting the location of the house, and that Pungsu was not just a theory but had a practical effect in preserving the life and property of the family under the risky circumstances of the time.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.237-238
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• 2016

This paper describes Web-based information sharing mechanism in our hazard map creation support system. This system aims at collecting the unique information received from residents and raising resident's consciousness to disasters by recording hazardous locations where residents feel danger in case of disasters. We have implemented a mechanism to share and integrate data of each terminal through a Web server. We expect that this information sharing effects scalability and usefulness of our system by utilizing collected local hazard information of each district.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.59-71
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• 2019

In Mountainous Districts Management Act of Korea Forest Service, slope and elevation criteria are operated to regulate the indiscriminate use of risky land parcels when forestland is converted to other land use types. However, there is a limitation in considering topographical variation with only such two indices in the land parcel. Therefore, in order to supplement insufficient criteria, the slope type standard was developed using Catena, and the ecological condition improved terrain standards. Firstly, the ratio of 'risky slope' in a target forestland parcel was defined to decrease the risk of disasters such as landslides. Secondly, the standard of the ecological location condition was proposed as ecological score by integrating age, diameter and soil depth classes in the target forestland parcels. Thereby, we could prepare reasonable standards that can reduce forestland disasters and ecological damages, as suggesting new topographical and ecological assessment methods for forestland use conversion.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.122-131
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• 2017

This study was a drone-utilized case study motivated by that drones can obtain sophisticated video image data previously not feasible. The dilemma zones on selected intersection approaches were identified and locations of drivers' decision making to stop or go at the onset of yellow were determined by analyzing drone video images. The gap between the drivers' decision making location and invisible stop/go border line provided by the yellow time interval was defined as "risky passing zone". To improve the dilemma zone safety problems, re-optimization of yellow time intervals and introduction of new pavement marking that can help drivers decision making on yellow indication are suggested.

• Earthquakes and Structures
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• v.16 no.4
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• pp.437-453
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• 2019

This study investigates a new optimal placement method for viscous dampers between structures in order to prevent pounding of adjacent structures with different dynamic characteristics under earthquake effects. A relative displacement spectrum is developed in two single degree of freedom system to reveal the critical period ratios for the most risky scenario of collision using El Centro earthquake record (NS). Three different types of viscous damper design, which are classical, stair and X-diagonal model, are considered to prevent pounding on two adjacent building models. The objective function is minimized under the upper and lower limits of the damping coefficient of the damper and a target modal damping ratio. A new algorithm including time history analyses and numerical optimization methods is proposed to find the optimal dampers placement. The proposed design method is tested on two 12-storey adjacent building models. The effects of the type of damper placement on structural models, the critical period ratios of adjacent structures, the permissible relative displacement limit, the mode behavior and the upper limit of damper are investigated in detail. The results of the analyzes show that the proposed method can be used as an effective means of finding the optimum amount and location of the dampers and eliminating the risk of pounding.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.301-310
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• 2022

Accurate prediction of mixed ground conditions ahead of a tunnel face is of vital importance for safe excavation using tunnel boring machines (TBMs). Previous studies have primarily focused on electrical resistivity surveys from the ground surface for geotechnical investigation. In this study, an FE (finite element) numerical model was developed to simulate electrical resistivity surveys for the prediction of risky mixed ground conditions in front of a tunnel face. The proposed FE model is validated by comparing with the apparent electrical resistivity values obtained from the analytical solution corresponding to a vertical fault on the ground surface (i.e., a simplified model). A series of parametric studies was performed with the FE model to analyze the effect of geological and sensor geometric conditions on the electrical resistivity survey. The parametric study revealed that the interface slope between two different ground formations affects the electrical resistivity measurements during TBM excavation. In addition, a large difference in electrical resistivity between two different ground formations represented the dramatic effect of the mixed ground conditions on the electrical resistivity values. The parametric studies of the electrode array showed that the proper selection of the electrode spacing and the location of the electrode array on the tunnel face of TBM is very important. Thus, it is concluded that the developed FE numerical model can successfully predict the presence of a mixed ground zone, which enables optimal management of potential risks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.851-856
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• 2015

As crime has actually increased in recent years, various mobile applications related to safety and emergency measure have received much attention. Therefore, IoT (Internet of Things) technologies, which connect various physical objects with Internet communication, have been also paid attention and then diverse safety services based on IoT technologies have been on the increase. However, existing mobile safety applications are simply based on location based service (LBS). Also, as they are independently operated without the help of another safety systems, they cannot efficiently cope with various safety situations. So, this paper proposes the efficient smart safety service architecture with both the risky situation detection using user location as well as various sensing information and the risk congruence measure using the streetlight infrastructure. Additionally, UDID (unique device identifier) is utilized for the secure communication with the control center.