• 한국산학기술학회논문지
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• 제11권5호
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• pp.1564-1572
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• 2010

본 연구에서는 3축 가속도 신호를 이용하여 낙상과 낙상 방향을 검출하는 시스템을 구현하였다. 가속도 신호는 3축 가속도 센서로부터 획득하였으며, 획득된 신호를 USB 인터페이스를 통하여 PC에 전달하였다. PC에 전송된 신호를 제안한 알고리즘을 사용하여 낙상을 검출하였으며, 퍼지 분류기를 사용하여 낙상의 방향을 분류하였다. 실험을 위하여 실험대상군 6명 선정하였으며, 가슴에 가속도계를 부착한 후 실험을 수행하였다. 실험대상자는 5초 동안 정상 보행을 한 후 4 가지 방향(전 후 좌 우)으로 낙상이 발생하도록 하였으며, 낙상에 소요되는 시간은 최소 2초로 설정하였다. 본 연구에서 제안된 알고리즘을 이용하여 낙상을 검출하였으며 낙상 발생 후 1초부터 데이터를 분석하고 퍼지 분류기를 이용하여 낙상방향을 분류하였다. 낙상 검출율은 평균 94.79%이었다. 낙상 방향에 따른 분류율은 front_fall은 95.83%, back_fall은 100%, left_fall 은 87.5%, right_fall은 95.83%이었다.

• 융합신호처리학회논문지
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• 제24권4호
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• pp.213-220
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• 2023

낙상은 일상의 활동 중에 예기치 않게 발생하여 생활에 많은 어려움을 초래한다. 본 연구는 고위험 직종 종사자들의 낙상 감지를 위한 시스템을 구성하고 자료를 수집하여 예측 모델에 적용함으로써 그 유효성을 검증하는 것을 목적으로 하였다. 이를 위해 가속도센서와 자이로센서를 통해 가속도 신호와 방위각을 산출하여 낙상 여부를 감지하는 웨어러블 기기를 구성하였다. 그리고 연구 참여자들이 이 기기를 복부에 착용하고 정해진 활동을 수행하는 과정에서 낙상과 관련한 동작으로부터 필요한 데이터를 측정하고 기기 내에 존재하는 블루투스 장치를 통해 컴퓨터로 전송하였다. 이렇게 수집된 데이터를 필터링 등을 통해 처리하여 딥러닝 알고리즘들인 1D CNN, LSTM, CNN-LSTM에 근거한 낙상 감지 예측 모델들에 적용하고 그 결과를 평가하였다.

• PNF and Movement
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• 제22권1호
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• pp.43-54
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• 2024

Purpose: Falls among persons older than 65 years are a significant concern due to their frequency and severity. This study aimed to develop a vest-type embedded artificial intelligence (AI) system capable of detecting and predicting falls in various scenarios. Methods: In this study, we established and developed a vest-type embedded AI system to judge and predict falls in various directions and situations. To train the AI, we collected data using acceleration and gyroscope values from a six-axis sensor attached to the seventh cervical and the second sacral vertebrae of the user, considering accurate motion analysis of the human body. The model was constructed using a neural network-based AI prediction algorithm to anticipate the direction of falls using the collected pedestrian data. Results: We focused on developing a lightweight and efficient fall prediction model for integration into an embedded AI algorithm system, ensuring real-time network optimization. Our results showed that the accuracy of fall occurrence and direction prediction using the trained fall prediction model was 89.0% and 78.8%, respectively. Furthermore, the fall occurrence and direction prediction accuracy of the model quantized for embedded porting was 87.0 % and 75.5 %, respectively. Conclusion: The developed fall detection and prediction system, designed as a vest-type with an embedded AI algorithm, offers the potential to provide real-time feedback to pedestrians in clinical settings and proactively prepare for accidents.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.197-206
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• 2003

With the growing usage of the networks, the world-wide Internet has become the main means to exchange data and carry out transactions. It has also become the main means to attack hosts. To solve the security problems which occur in the network such as Internet, we import software products of network security elements like an IDS (Intrusion Detection System) and a firewall. In this paper, we have designed and constructed the General Simulation Environment of Network Security model composed of multiple IDSes and a firewall which coordinate by CNP (Contract Net Protocol) for the effective detection of the intrusion. The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls tie execution of agents or a contractee, who performs intrusion detection. In the Network Security model, each model of simulation environment is hierarchically designed by DEVS (Discrete EVent system Specification) formalism. The purpose of this simulation is to evaluate the characteristics and performance of CNP architecture with rete pattern matching algorithm and the application of rete pattern matching algorithm for the speeding up the inference cycle phases of the intrusion detection expert system.

• 한국컴퓨터정보학회논문지
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• 제27권6호
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• pp.23-31
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• 2022

최근 코로나 19가 유행하고 더불어 고령화 시대와 1인 가구 증가로 인해 가구 구성원이 집에서 다양한 활동을 하며 머무는 시간이 매우 증가하였다. 본 연구에서는 노인을 포함한 1인 가구의 구성원들의 이상 징후를 탐지하기 위한 알고리즘을 제안한다. 홈 CCTV를 통한 영상 센서 알고리즘, 스마트폰에 내장된 가속도 센서를 이용한 활동 센서 알고리즘 및 2D LiDAR 센서 기반의 LiDAR 센서 알고리즘을 이용한 사람의 움직임 및 낙상 탐지 결과를 기반으로 이상 징후를 탐지하는 알고리즘들을 제안한다. 하지만, 각 단일 센서 기반 알고리즘은 센서가 가진 한계점으로 인해 특정 상황에서 이상징후를 탐지하기 어려운 단점을 가지고 있다. 그에 따라 단일 센서 기반 알고리즘만을 사용한 것보다 다양한 상황에서 이상 징후를 탐지하기 위해 각 알고리즘을 결합하는 융합 방식을 제안한다. 우리는 각 센서로 수집한 데이터를 통해 알고리즘들의 성능을 평가하고, 특정 시나리오들을 통하여 알고리즘 하나만 사용하여 정확한 이상 징후를 탐지할 수 없는 상황에서도 융합 방식을 통해 서로 보완하여 정확한 이상 징후를 효율적으로 탐지할 수 있음을 보여준다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.1057-1060
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• 1999

For efficient storage and retrieval of large video data sets, automatic video scene change detection is a necessary tool. Video scene changes fall into two categories, namely fast and gradual scene changes. The gradual scene change effects include, dissolves, wipes, fades, etc. Although currently existing algorithms are able to detect fast scene changes quite accurately, the detection of gradual scene changes continue to remain a difficult problem. In this paper, among various gradual scene changes, we focus on dissolves. The algorithm uses a subset of the entire video, namely the sequence of DC images, for improvement of detection velocity

• 센서학회지
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• 제22권1호
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• pp.54-64
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• 2013

In this study, we developed a falling recognition system to transmit SMS data through CDMA communication using a three axises acceleration sensor and a two axises gyro sensor. 5 healthy men were selected into a control group, and the fall recognition system using the three axises acceleration sensor and the two axises gyro sensor was devised to conduct an experiment. The system was attached to the upper of their sternum. According to the experiment protocol, the experiment was carried out 3 times repeatedly divided into 3 specific protocols: falling during gait, falling in stopped state, and falling in everyday life. Data obtained in the falling recognition system and LabVIEW 8.5 were used to decide if falling corresponds to that regulated in an analysis program applying an algorithm proposed in this study. In addition, results from falling recognition were transmitted to designated cellular phone in a SMS (Shot Message Service) form. These research results show that an erroneous detection rate of falling reached 19% in applying an acceleration signal only; 6% in applying an angular velocity; and 2% in applying a proposed algorithm. Such finding suggests that an erroneous detection rate of falling is improved when the proposed algorithm is applied incorporated with acceleration and angular velocity. In this study therefore, we proposed that a falling recognition system implemented in this study can make a contribution to the recognition of falling of the aged or the disabled.

• ETRI Journal
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• 제44권4호
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• pp.654-671
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• 2022

Accidental falls frequently occur during activities of daily living. Although many studies have proposed various accident detection methods, no high-performance accident detection system is available. In this study, we propose a method for integrating data and accident detection algorithms presented in existing studies, collect new data (from two stunt performers and 15 people over age 60) using a developed wearable device, demonstrate new features and related accident detection algorithms, and analyze the performance of the proposed method against existing methods. Comparative analysis results show that the newly defined features extracted reflect more important risk factors than those used in existing studies. Further, although the traditional algorithms applied to integrated data achieved an accuracy (AC) of 79.5% and a false positive rate (FPR) of 19.4%, the proposed accident detection algorithms achieved 97.8% AC and 2.9% FPR. The high AC and low FPR for accidental falls indicate that the proposed method exhibits a considerable advancement toward developing a commercial accident detection system.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.703-706
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• 2007

인체의 실시간 활동 모니터링은 활동량과 활동능력에 대한 중요한 정보를 제공한다. 본 연구에서 3축 가속도 센서와 무선센서노드를 활용하여 인체의 활동을 평가하고 응급상황을 인지할 수 있는 시스템을 개발하였다. 본 연구에 의해 구현된 실시간 시스템은 구현된 분류알고리즘을 통해 다양한 자세와 자세변화를 분류할 수 있으며, 추가적으로 낙상을 감지할 수 있다. 구현된 시스템의 성능평가 결과 높은 분류 정확성을 보였다.

• 한국멀티미디어학회논문지
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• 제23권2호
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• pp.282-292
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• 2020

In order to minimize casualties from marine vessel accidents that occur frequently at home and abroad, it is important to ensure the safety of the passengers aboard the vessel in the event of an accident. There is an EPIRB system as a system for disaster preparedness in the marine situation currently on the market, but there is a problem that the price is very expensive. In order to overcome the cost problem, which is a disadvantage of previous system, LoRaWAN-based communication is used. LoRaWAN communication-based vessel positioning and risk detection system based on LoRaWAN communication transmits measurement data of each module using two Beacon and GPS modules to stably perform position measurement for both indoor and outdoor situations. The rider danger situation detection system can detect the safety status of the rider using the 3-axis acceleration sensor, collect data from the rider positioning system and the rider safety status detection system, and send to server using LoRa communication. When conducting communication experiments in the long-distance maritime situation and actual communication experiments using the implemented system, it was found that the two experiments showed over 90% communication success rate on average.