• 제목/요약/키워드: pre-impact

검색결과 902건 처리시간 0.024초

임계값 기반 충격 전 낙상검출 및 실제 노인 데이터셋을 사용한 검증 (Threshold-based Pre-impact Fall Detection and its Validation Using the Real-world Elderly Dataset)

  • 김동권;이승희;구범모;양수민;김영호
    • 대한의용생체공학회:의공학회지
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    • 제44권6호
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    • pp.384-391
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    • 2023
  • Among the elderly, fatal injuries and deaths are significantly attributed to falls. Therefore, a pre-impact fall detection system is necessary for injury prevention. In this study, a robust threshold-based algorithm was proposed for pre-impact fall detection, reducing false positives in highly dynamic daily-living movements. The algorithm was validated using public datasets (KFall and FARSEEING) that include the real-world elderly fall. A 6-axis IMU sensor (Movella Dot, Movella, Netherlands) was attached to S2 of 20 healthy adults (aged 22.0±1.9years, height 164.9±5.9cm, weight 61.4±17.1kg) to measure 14 activities of daily living and 11 fall movements at a sampling frequency of 60Hz. A 5Hz low-pass filter was applied to the IMU data to remove high-frequency noise. Sum vector magnitude of acceleration and angular velocity, roll, pitch, and vertical velocity were extracted as feature vector. The proposed algorithm showed an accuracy 98.3%, a sensitivity 100%, a specificity 97.0%, and an average lead-time 311±99ms with our experimental data. When evaluated using the KFall public dataset, an accuracy in adult data improved to 99.5% compared to recent studies, and for the elderly data, a specificity of 100% was achieved. When evaluated using FARSEEING real-world elderly fall data without separate segmentation, it showed a sensitivity of 71.4% (5/7).

충격력 재현에 관한 연구 (A Study on the Impact Force Reconstruction)

  • 조창기;이규섭;류봉조;이종원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.949-953
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    • 1996
  • Force shape control for impact test is required in order to simulate dynamic reponse of structures which is subjected to impact force. In this paper, the mechanisms of contact and impact force generation are analyzed and tested with a simple test equipment. It was carried out for the pre-design of impact force reconstruction apparatus.

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Sentiment Analysis of COVID-19 Tweets: Impact of Pre-processing Step

  • Ayadi, Rami;Shahin, Osama R.;Ghorbel, Osama;Alanazi, Rayan;Saidi, Anouar
    • International Journal of Computer Science & Network Security
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    • 제21권3호
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    • pp.206-211
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    • 2021
  • Internet users are increasingly invited to express their opinions on various subjects in social networks, e-commerce sites, news sites, forums, etc. Much of this information, which describes feelings, becomes the subject of study in several areas of research such as: "Sensing opinions and analyzing feelings". It is the process of identifying the polarity of the feelings held in the opinions found in the interactions of Internet users on the web and classifying them as positive, negative, or neutral. In this article, we suggest the implementation of a sentiment analysis tool that has the role of detecting the polarity of opinions from people about COVID-19 extracted from social media (tweeter) in the Arabic language and to know the impact of the pre-processing phase on the opinions classification. The results show gaps in this area of research, first of all, the lack of resources when collecting data. Second, Arabic language is more complexes in pre-processing step, especially the dialects in the pre-treatment phase. But ultimately the results obtained are promising.

예비 중등교사의 다문화 인식이 다문화 효능감에 미치는 영향 (The Impact of Awareness of Multiculture on Efficacy of Multiculture in Pre-service Secondary Teachers)

  • 이기용;박창언
    • 수산해양교육연구
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    • 제26권5호
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    • pp.1026-1036
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    • 2014
  • The purpose of this research is to find the impact of multicultural awareness of pre-service secondary teachers on multicultural efficacy. Specific content of the study for achieving this purpose is as follows: First, the correlation between multicultural awareness of pre-service secondary teachers and multicultural efficacy was analyzed. Second, the effect relation between multicultural awareness of pre-service secondary teachers and multicultural efficacy was examined. As part of quantitative research, the method of study was a survey targeting 234 pre-service Secondary teachers who were sophomores, juniors and seniors at D University, P University and S University located in Busan. The study results earned from this process are as below: First, statistically significantly high positive correlation existed between multicultural awareness of pre-service secondary teachers and multicultural efficacy. The areas of acceptance, openness and respect, which are the sub-scale of multicultural awareness of pre-service secondary teachers, showed high positive correlations with all sub-scale of multicultural efficacy including general efficacy, efficacy in instructional function, efficacy in caring perspectives and efficacy in helping multicultural families. Second, the sub-scale of multicultural awareness that significantly affected general efficacy in the sub-scale of multicultural efficacy of pre-service secondary teachers was acceptance and respect. The sub-scale of multicultural awareness that significantly affected efficacy in instructional function was acceptance. The sub-scale of multicultural awareness that significantly affected efficacy in caring perspectives was acceptance and respect. The sub-scale of multicultural awareness that significantly affected efficacy in helping multicultural families was respect. It showed that openness in the sub-scale of multicultural awareness did not affect multicultural efficacy much.

도서관 견학이 예비사서의 사서 핵심능력 중요도 인식에 미치는 영향 (The Impact of the Library Tour for Pre-librarians on the Importance Perception of the Librarian Core Competency in South Korea)

  • 정종기
    • 한국문헌정보학회지
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    • 제49권1호
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    • pp.279-296
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    • 2015
  • 본 연구의 목적은 예비사서들이 도서관 견학프로그램을 통해 다양한 도서관의 사서직무들을 직접 보고 들어봄으로써 사서 핵심능력 중요도 인식에 어떠한 변화가 있는지를 밝혀 사서양성기관, 도서관의 견학담당 사서, 그리고 예비사서들에게 도서관 견학이 갖는 교육적 의의를 제시하기 위함이다. 도서관 견학프로그램에 참여한 예비사서 29명을 대상으로 도서관 견학프로그램을 적용하기 사전 사후 사서 핵심능력 중요도 인식에 관한 설문조사 분석 결과, 도서관 견학이 예비사서들의 사서 핵심능력에 대한 중요도 인식에 통계적으로 유의미한 차이가 있었다. 예비사서의 도서관 견학프로그램이 향후 사서 직무수행을 위한 사서 핵심능력 중요도 인식에 영향을 주어 예비사서의 자기주도적 학습에 동기유발이 될 수 있으며 사서양성기관에서는 현장기반의 사서 양성 교육과정 개발과 실행에 필요한 기초자료로 활용될 수 있다는 점에서 연구의 의의가 있다.

Pre-college Study Abroad and Its New Impact on Korean Mothers

  • Lee, Ji-Yeon
    • 비교문화연구
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    • 제32권
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    • pp.81-107
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    • 2013
  • This study examines pre-college study abroad (PSA, Chogi yuhak), which is one of the fastest growing phenomena among the various efforts for Koreans to learn English. The discussion includes the reasons why PSA has become so popular in the last decade under the name of globalization, the problems it has caused, and its new impact that this phenomenon has on Korean mothers. This study argues that PSA boom provides Korean mothers with an opportunity to pursue their own self-realization by studying abroad with their school aged children. These "new wild geese" mothers, who make double investments in their own education as well as in their children's in the U.S. represent important aspects of the contemporary Korean society regarding education, gender and neoliberal social atmosphere.

예비 유아교사의 낙관성에 따른 스트레스 지각과 사회적 지지가 주관적 안녕감에 미치는 영향 (The Effects of Stress Perception and Social Support on Subjective Well-being According to the Optimism Levels of Pre-service Early Childhood Teachers)

  • 박영신
    • 아동학회지
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    • 제33권1호
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    • pp.63-80
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    • 2012
  • The purpose of this study was to analyze the effects of stress perception and social support on subjective well-being according to differing levels of optimism. The participants in this study were 230 pre-service early childhood teachers, majoring in early childhood education at two universities located in Daegu, Gyeongbuk province. The results of this study could be summarized as follows. First, pre-service early childhood teachers were shown to be more optimistic, be more satisfied with life, and had higher positive emotion rates than average. They also showed lower stress perception and negative emotion rates than average. Second, the highly optimistic group showed higher levels than the less optimistic group in terms of both satisfaction with life and positive emotions. Third, the stress perception in both the highly optimistic group and the less optimistic group had an impact on their satisfaction with life, positive emotions, and negative emotions. The degree of peer support perceived by the highly optimistic group showed an impact on satisfaction with life and negative emotions, whereas the degree of parental support perceived by the less optimistic group showed an impact on their levels of satisfaction with life.

Effects of Pre-Strains on Failure Assessment Analysis to API 5L X65 Pipeline

  • Baek, Jong-Hyun;Kim, Young-Pyo;Kim, Woo-Sik;Seok, Chang-Sung
    • 비파괴검사학회지
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    • 제29권3호
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    • pp.219-223
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    • 2009
  • This paper prescribed the structural integrity of the API 5L X65 pipeline subjected to tensile pre-strain. The effects of pre-strain on the mechanical properties of API 5L X65 pipe were substantially investigated through a variety of the experimental procedures. Axial tensile pre-strain of 1.5, 5 and 10% was applied to plate-type tensile specimens cut from the pipe body prior to mechanical testing. Tensile test revealed that yield strength and tensile strength were increased with increasing tensile pre-strain. The increasing rate of the yield strength owing to the pre-strain is greater than that of the tensile strength. However, the pre-strain up to 5% had a little effect on the decreasing of the fracture toughness. The structural integrity of the API 5L X65 pipeline subjected to large plastic deformation was evaluated through the fitness-for service code.

LCA 기법을 활용한 스마트폰의 잠재적 환경영향평가 (Assessment of the Potential Environmental Impact of Smart Phone using LCA Methodology)

  • 허영채;배대식;오치영;서영진;이건모
    • 대한환경공학회지
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    • 제39권9호
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    • pp.527-533
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    • 2017
  • 제조공정이 기술 집약적인 반면 제품 수명이 짧아 다량으로 버려지는 스마트폰의 환경영향에 관심이 커지고 있다. 이 연구에서는 전과정평가 기법을 기반으로 스마트폰의 다양한 환경영향을 정량적으로 분석, 평가하였다. ISO 14040 시리즈 표준에 의거한 전과정평가를 수행하였고, 스마트폰의 제조전, 제조, 유통, 사용 및 폐기를 포함하는 전과정 단계를 시스템경계에 포함하였다. 평가한 10개 환경영향범주 모두에서 제조전단계가 가장 큰 환경영향을 나타내었다. 지구온난화 영향은 제조전단계, 유통단계, 사용단계, 제조단계, 폐기단계경우 각각 52.6%, 23.9%, 15.7%, 7.0% 및 0.8% 이었다. 스마트폰 제조전단계의 부품별 환경영향은 PCB, 배터리, 디스플레이 모듈 순이었다. 따라서 스마트폰의 전과정 환경영향 저감을 위해서는 스마트폰 소형/경량화를 통해 자원사용량을 줄이고, 자원순환성을 높일 수 있는 친환경 소재를 적용하여 제조전단계의 환경영향을 줄이려는 노력이 필요하다.

강화재파단이 있는 복합재료의 저속 충격특성 (Impact Properties of CFRP Laminates with Initial Fiber Failures)

  • 박중권;강창규;김철;김태우
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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    • pp.67-70
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    • 2005
  • The carbon fiber reinforced/epoxy laminated composites were fabricated with initial fiber failures within the unidirectional fiber pre-pregnated ply. The fiber failures were made intentionally either parallel to and/or perpendicular to the unidirectional fibers within the ply. The pre-made clear-cut cracks were found to be healed partially after laminating process. The laminates were impacted with or without initial fiber failures within the laminates. The force versus deflection curves were compared. The partially healed laminates showed the reduced laminate stiffness as compared to those without any intentional fiber failures. The impact curves were compared with size and the location of the initial failures varied.

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