• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.76-86
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• 2013

As the basic Kalman filter is limited to be used for indoor navigation, and particle filters incur serious computational overhead, especially in mobile devices, we propose an adaptive hybrid filter for WiFi-based indoor positioning systems. The hybrid filter utilizes the same prediction framework of the basic Kalman filter, and it adopts the notion of particle filters only using a small number of particles. Restricting the predicts of a moving object to a small number of particles on a way network and substituting a dynamic weighting scheme for Kalman gain are the key features of the filter. The adaptive hybrid filter showed significantly better accuracy than the basic Kalman filter did, and it showed greatly improved performance in processing time and slightly better accuracy compared with a particle filter.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.261-262
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• 2020

현대에 흔히 쓰이는 도어락은 안전과 보안등의 목적과 편리함을 목적에 두고 있다. 실제로 그전에 쓰던 열쇠보다 더 편리하고 분실염려도 없고 복제키 등으로 인한 사건, 사고로 인한 범죄율이 줄어들었다. 도어락은 사용자가 손으로 직접 비밀번호를 입력하여 잠금을 해제하는 방식이고 이 과정에서 도어락에 지문이나 표시가 남으며 비밀번호가 주위에 쉽게 노출될 수 있다. 본 논문은 위의 문제를 해결하기 위해 아두이노로 라즈베리파이와 앱을 무선 통신하여 '원격 제어가 가능한 스마트 도어락'을 고안했다. 아두이노 와이파이 모듈을 통해 스마트폰으로 도어락을 원격으로 제어할 수 있으며 라즈베리파이 카메라 모듈과 초음파 센서를 통해 도어락에 접근하는 사람을 감지하고 확인할 수 있다. 이 기능으로 범죄를 예방할 수 있으며 자녀들의 귀가 여부도 확인할 수 있고 문을 열어줘야 할 상황에 비밀번호 노출없이 문을 열어줄 수 있다.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.3
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• pp.289-299
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• 2024

In the Pedestrian Dead Reckoning (PDR)/Global Positioning System (GPS)/Wi-Fi-integrated navigation system for indoor/outdoor continuous positioning of pedestrians, the process of detecting outliers in measurements is very important. When accurate location information from measurements is used, reliable correction data can be generated during the fusion filtering process. However, abnormal measurements may occur in certain situations, such as indoor/outdoor transitions, which can degrade filter performance and lead to significant errors in the estimated position. To address this issue, this paper proposes a method for detecting outliers in measurements based on Rényi Divergence (RD). When the deviation of the RD value is large, the measurements are considered outliers, and positioning is performed using only pure PDR. Based on experiments conducted with real data, it was confirmed that outliers were effectively detected for abnormal measurements, leading to an improvement in the performance of pedestrian navigation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.657-659
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• 2018

In real life, We are using IoT technology directly. IoT technology has been applied in many fields and has developed continuously. Internet of Things is a technology or environment that attaches sensors to objects and sends and receives data through internet in real time. In this paper, if a password is wrong more than three times, the existing password is initialized and randomly changed. Changed password data seeks to realize that push alarms are sent via the app to the user or administrator. We have studied an Indono-based IoT system that can send real-time data to smart phones through WiFi. smart door locks are intended to implement them using Aduino, fingerprint sensor, camera sensor, Wi-Fi shield, Android Studio, and door lock components.