• 한국콘텐츠학회논문지
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• 제15권2호
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• pp.101-108
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• 2015

위치공유기반 서비스(Location-sharing based service)는 사용자가 친구관계를 맺고 있는 다른 사용자와 자신의 위치정보를 공유하는 서비스를 일컫는다. 이 때, 이 위치정보는 서비스 제공자(SP, Service Provider)를 통해 공유되며, 자신의 위치정보는 서비스 제공자에게 노출되게 된다. 이로써 개인의 위치정보가 SP에게 노출되는 프라이버시 문제가 제기되어 왔고, 이를 보호하기 위한 메커니즘들이 제안되었다. 본 논문에서는 위치공유기반 서비스의 종류와 그 특징을 살펴보고, 이를 위한 프라이버시 보호 메커니즘들의 연구 동향을 조사한다. 조사된 기존 메커니즘 분석을 통해, 현 서비스에 적합한 프라이버시 메커니즘 설계 방향 및 향후 연구 방향을 제언한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권2호
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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.

• 한국환경보건학회지
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• 제35권6호
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• pp.461-467
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• 2009

Exposure analysis is a critical component of determining the health impact of pollutants. Global positioning systems (GPS) could be useful in developing time-location information for use in exposure analysis. This study compares four low cost GPS receivers with data logging capability (Garmin 60, Garmin Forerunner 201, GeoStats GeoLogger and Skytrx minitracker MT4100) in terms of accuracy, precision, and ease of use. The accuracy of the devices was determined at two known National Geodetic Survey points. The coordinates logged by the devices were compared when the devices were carried while walking and driving. The Garmin 60 showed better accuracy and precision than the GeoLogger when they were placed at the geodetic points. The Forerunner and Skytrx did not record when they were kept stationary. When the subject wore the devices while walking, the location of the devices differed by about 8 m on average between any two device combinations involving the four devices. The distance between the coordinates logged by the devices decreased when the devices were carried with their antennas facing the sky. All the devices showed similar routes when they were used in a car. All the devices except the Forerunner had satisfactory signal reception when they were worn and when they were carried in the car. The GeoLogger is less comfortable for the subject because of specific wearing requirements. This evaluation found that the Garmin 60 and the Skytrx may be useful in personal exposure analysis studies to record time-location data.

• 정보처리학회논문지C
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• 제13C권5호
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• pp.595-600
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• 2006

오늘날 저가의 RFID 기술은 리더와 태그사이에 물리적인 접촉 없이 인식 가능한 기술로서 기업과 학술적 분야에서 많은 각광을 받고 있다. 그러나 태그의 정보가 전송과정에 무선특성에 따른 과도한 정보 노출과 사용자의 위치정보 추적과 같은 심각한 프라이버시 침해를 유발시킨다. 특히 읽기전용 태그에서의 보안문제는 단지 물리적 방법으로만 해결하고 있다. 이 논문에서는 간단한 XOR연산과 부분 ID를 이용하여 다양한 공격에 안전하며 읽기전용 태그에 적합한 저비용 인증 프로토콜을 제안한다. 제안 프로토콜은 재전송, 도청, 위장 공격에 안전하며 또한 위치 프라이버시가 보장된다.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.368-374
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• 2024

During an X-ray examination, the beam of radiation is dispersed in many directions. We believe that managing radiation dose is about providing transparency to users and patients in the accurate investigation and analysis of radiation dose. The purpose of measuring the radiation dose as a function of location is to ensure that medical personnel using the equipment or participating in the operating room are minimally harmed by the different radiation doses depending on their location. Four mobile diagnostic X-ray units were used to analyze the radiation dose depending on the spatial location. The image intensifier and the flat panel detector type that receives the image analyzed the dose by angle to measure the distribution of the exposure dose by location. The radiation equipment used was composed of four units, and measuring devices were installed according to the location. The X-ray (C-arm) was measured by varying the position from 0 to 360 degrees, and the highest dose was measured at the center position based on the abdominal position, and the highest dose was measured at the 90° position for the head position when using the image intensifier equipment. The operator or medical staff can see that the radiation dose varies depending on the position of the diagnostic radiation generator. In the image intensifier and flat panel detector type that accepts images, the dose by angle was analyzed for the distribution of exposed dose by position, and the measurement method should be changed according to the provision of dose information that is different from the dose output from the equipment according to the position.

• 한국분무공학회지
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• 제23권2호
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• pp.81-89
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• 2018

The objective of this study is to estimate the level of exposure of traffic-related air pollutants (TRAPs) on the pedestrians in Seoul area. The road network's link-based pollutant emission was calculated by using a set of mobile source emission factor package and associated activity information. The population information, which is the number of pedestrian, was analyzed in conjunction with the link-based traffic emissions in order to quantify exposure level by selected 23 spots. We proposed the Exposure Intensity, which is defined by the amount of traffic emission and the population, to quantify the probability of exposure of pedestrian. Link-based traffic NOx and PM emissions vary by up to four times depending on the location of each spot. The Hot-spots is estimated to be around 1.8 times higher Exposure Intensity than the average of the 23 selected spots. The information of Exposure Intensity of each spot allows us to develop localized policies for air quality and health. Even in the same area, the Exposure Intensity over time also shows a large fluctuation, which gives suggestions for establishing site-specific counter-measures.

• 인터넷정보학회논문지
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• 제23권2호
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• pp.29-35
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• 2022

자외선은 노출 정도에 따라 인체에 유익 또는 유해한 영향을 미치므로 개인별 적정 노출을 위해서는 정확한 자외선(UV) 정보가 필요하다. 국내의 경우 기상청에서 생활기상정보의 한 요소로 자외선 정보를 제공하고 있으나 지역별 자외선 지수(UVI, Ultraviolet Index)로 사용자 위치의 정확한 UVI를 제공하지는 못하고 있다. 일부에서는 정확한 UVI의 취득을 위해 직접 계측기를 운용하지만 비용이나 편의성에 문제가 있고, 태양의 복사량과 운량 등 주변 환경요소를 통해 자외선 양을 추정하는 연구도 소개되었으나 개인별 서비스 방법을 제시하지는 못하였다. 이에 본 논문에서는 각 개인별 위치에서의 정확한 UVI 제공을 위한 태양객체 정보와 태양광 특성을 이용한 UVI 산출 딥러닝 모델을 제안한다. 기 수집한 하늘이미지 및 태양광 특성을 분석하여 태양의 위치 및 크기, 조도 등 UVI와 상관도가 높은 요소들을 선정한 후 DNN 모델을 위한 데이터 셋을 구성한다. 이후 하늘이미지로부터 Mask R-CNN을 통해 추출한 태양객체 정보와 태양광 특성을 입력하여 UVI를 산출하는 DNN 모델을 구현한다. 국내 UVI 권고기준을 고려, UVI 8이상과 미만인 날에 대한 성능평가에서는 기준장비 대비 MAE 0.26의 범위 내 정확한 UVI의 산출이 가능하였다.

• 한국산업보건학회지
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• 제20권2호
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• pp.102-110
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• 2010

Personal exposure relies on characteristics of time activity patterns of the population of concern as human activities impact the timing, location, and level of personal exposure. The information about time spent in microenvironments plays a critical role for personal exposure to air pollutants. It is useful to determine the precise times of the day that the subjects are in certain locations or engaging in specific activities because exposure to some air pollutants can depend on temporal trends. This study investigated time activity pattern for workers of Korean population over 19 years old with 8,778 workers in weekday. The residential indoor times were 12 hours. Time activity was different by gender and the mean times stayed at home in weekday were 12.9 hours in female and 11.42 hours in male, respectively. The major factors on residential indoor time and workplace time were age, monthly income, occupation and industry type, work position, education, and gender. Considering shorter than those in other countries, Korean workers spent less time at home after the working hours. Determinants of time activity pattern need to be taken into account in exposure assessment, epidemiological analyses, exposure simulations, as well as in the development of preventive strategies. Since there are substantial difference of Korean worker activity pattern, this information can be critical for exposure assessment in Korea.

• 한국통신학회논문지
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• 제31권7C호
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• pp.755-761
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• 2006

기존 RFID 기술은 리더와 태그사이에 물리적인 접촉 없이 인식 가능하고 태그의 정보가 전송과정에 무선특성에 따른 과도한 정보 노출과 사용자의 위치정보 추적과 같은 심각한 프라이버시 침해를 유발시킨다. 특히 읽기전용 태그에서의 보안문제는 단지 물리적 방법으로만 해결하고 있다. 이 논문에서는 간단한 XOR연산과 부분 ID를 이용하여 다양한 공격에 안전하며 읽기전용 태그에 적합한 저비용 인증 프로토콜을 제안한다. 제안 프로토콜은 재전송, 도청, 위장 및 위치 추적 등 공격에 안전하다.

• 한국통신학회논문지
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• 제36권8B호
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• pp.929-938
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• 2011

본 논문에서 제안한 Dummy를 이용한 Cloaking 영역 설정 알고리즘은 기존의 Privacy Grid의 색인 구조에 건물 그룹화 항목을 추진시켜 Privacy Grid의 여러 셀에 걸쳐져 있는 건물을 중복으로 카운트하던 문제를 해결하였고, 각 건물 모서리에 인접한 셀을 검색한 후 K값을 증가시킴으로써 기존의 GBC(Grid-Based Cloaking) 기법의 최소 Cloaking 영역 설정으로 인한 개인 위치 정보 보호 유출 문제점을 해결 하였다. 또한, 본 논문에서는 Cloaking 영역을 확장하기 전에 Dummy K 값으로 Privacy Grid와 GBC 보다 작은 Cloaking 영역을 설정할 수 있어 K값 검색시간을 단축시키고, Dummy K를 이용하여 사용자의 위치정보보호를 더 강화시킬 수 있다.