Earticle

Epoch in accelerometer measurements is an important option that af-fects the results of physical activity (PA) analysis. Many studies have been conducted to investigate the effect of epoch on PA output in ado-lescents, but few have been performed on highly active youth athletes. We aimed to examine the differences in energy expenditure and time spent in different activity intensities by applying various epoch lengths in adolescent athletes. The participants of this study comprised 31 male athletes aged 12 to 13 in basketball, soccer, and taekwondo teams. Ath-letes wore a tri-axial accelerometer attached to the right hip for 6 to 7 consecutive days, including sleeping time. Subsequently, the recorded data from the accelerometer were downloaded using the ActiLife soft-ware and analyzed by varying the epoch to 1, 10, 30, and 60 sec. Daily average metabolic equivalents (METs) increased as the epoch in-creased (F=2.918, P=0.037), showing a significant difference between 1 and 60-sec epochs. As epoch length increased, sedentary (0–1.5 METs) (F=94.001, P=0.000) and high intensity (6 METs and higher) activity time (F=3.536, P=0.017) decreased, while low (1.5–3 METs) (F=173.949, P= 0.000), moderate (3–6 METs) (F=70.792, P=0.000), and moderate-to-vig-orous activity (3 METs and higher intensity) (F=34.683, P=0.000) times increased. Comparing PA among adolescent athletes by varying epoch settings of accelerometers revealed differences in PA levels and time spent in different activity intensities. Future studies should consider the characteristic changes in the PA outputs according to the epoch length in very active adolescent athletes.

The purpose of this study was to determine the reliability and suitability of accelerometer measurements on gait asymmetry and balance in stroke patients. This literature review uses accelerometers to search for static and dynamic balance and gait asymmetry in adults diagnosed with stroke and to refer to the 2018 paper from 2008. The results of the compilation of the paper were as follows. The balance of the accelerometers showed measurements similar to those of the previous BBS and TUG. In other words, using the accelerometer to measure the balance suggests that it can be clinically useful. Next, studies that analyzed the gait asymmetry of accelerometers indicated that the algorithm's limits for estimating time were insufficient, but that the reliability tool for measuring the gait asymmetry was proven. This result shows that it is possible to analyze walking patterns through an accelerometer in individuals with hemiparetic stroke.

본 연구에서는 가속도 센서의 각 축의 값들을 이용해 숫자나 특정 입력 값을 기기에 전달할 수 있는 제스처 인식을 위한 센서 값들의 효율적인 사전 보정 알고리즘과 분류 알고리즘에 대해서 제안한다. 실험결과 보정 전과 보정 후의 X축과 Z축의 에러율을 통하여 전처리된 데이터가 생성됨을 알 수 있었다. 또한 전처리된 데이터에 적용할 정규화와 분류 알고리즘으로 구현한 인식기가 높은 인식률을 보여주었다.

In this Paper, we suggest the effective pre-correction algorithm on sensor values and the classification algorithm for gesture recognition that use values for each axis of the accelerometer to send data(a number or specific input data) to device. we know that creation of reliable preprocessed data in experimental results through the error rate of X-Axis and Y-Axis for pre-correction and post-correction. we can show high recognition rate through recognizer using the normalization and classification algorithm for the preprocessed data.

In this paper, we analyze user's manipulation and reaction in an accelerometer-based game interface, as compared with a touch joystick-based game interface. To roll the ball, the user carefully grabs and adjusts the smartphone with both hands in the accelerometer-based game interface; while the user very quickly clicks the up, down, left, right, buttons in the touch joystick-based game interface, because it is already familiar to the user. The accelerometer- based game interface is relatively more immersive and interesting than the touch joystick-based game interface; because the user gets more desired results by elaborately operating the game with both hands rather than by clicking the buttons with the thumb.

This paper presents a new type of optical silicon accelerometer using deep reactive ion etching (DRIE) and micro-stereolithography technology. Optical silicon accelerometer is based on a mass suspended by four vertical beams. A vertical shutter at the end of the mass can only moves along the sensing axis in the optical path between two single-mode optical fibers. The shutter modulates intensity of light from a laser diode reaching a photo detector. With the DRIE technique for (100) silicon, it is possible to etch a vertical shutter and beam. This ensures low sensitivity to accelerations that are not along the sensing axis. The microstructure for sensor packaging and optical fiber fixing was fabricated using micro stereolithography technology. Designed sensors are two types and each resonant frequency is about 15 kHz and 5 kHz.

현재 평균 수명 증가와 더불어 고령자의 일상 생활 중 안전 사고가 빈번히 발생하고 있으며, 이 중 낙상 사고가 큰 비중을 차지하고 있다. 피해를 최소화하기 위해서는 낙상 사고가 발생 시 신속하게 응급상황 대응기관으로 사고 발생 여부 및 위치를 알리는 기술이 필요하다. 본 연구에서는 가속도 센서가 탑재된 스마트 밴드와 영상 기반 자세 정보를 동시에 사용하여 낙상 여부를 판단하는 기법을 제안한다. 특히 복합 센서의 취득 정보 처리 지연시간을 일정 수준으로 관리하여, 응급 상황시에도 이를 활용할 수 있도록 하는 것을 목표로 한다. 이를 확인하기 위해 처리 프로세스의 지연시간을 분석하는 실험을 진행하였다.

최근까지 초고령사회의 도래와 함께 많은 국가에서 고령자의 신체활동과 신체기능, 체력수준에 관련된 평가가 수행되어 왔지만 통일된 방법이 없는 실정이며 정보 또한 부족한 현실이다. 세계최장수국 일본의 경우 국민건강 증진 방안으로 신체활동량 증진을 권장해 왔다. 다양한 가속도계가 일본과 미국 등에서 개발되어 온 현재 우리나라와 국제비교 에 적용하기 위해 측정도구들의 특징과 연구방법론적인 과제를 살펴보는 것은 중요한 의미를 지닌다. 선진국들로부터 초고령사회의 도래를 대비하기 위한 방안을 벤치마킹해야 하는 우리나라의 경우 신체활동량 평가 도구의 특성과 기능을 포함한 타당성 검토에도 관심을 가져야 한다. 본 연구의 목적은 고령자를 대상으로 가속도계를 활용하여 신체활동량을 측정 평가한 연구논문들의 특징과 최근 동향을 파악하고, 일본의 대표적인 가속도계의 구조와 신체활동 지표의 산출방법 및 타당성을 소개하는 데에 있다. 본 연구를 통해 2025년 초고령사회 진입을 목전에 둔 우리나라 고령자들의 건강한 장수 를 위한 신체활동량 평가 관련 후속 연구과제 탐색에 유용한 기초자료를 제공하고자 한다.

Until recently, with the advent of a super-aged society, evaluations related to the physical activity, physical function, and physical strength of the elderly have been conducted in many countries, but there is no unified method and information is insufficient. Japan, the world's longest-serving country, has recommended improving physical activity as a way to improve national health. Various accelerometers have been developed in Japan and the United States, but in order to apply them to international comparisons with Korea, it will be necessary to examine the characteristics of measurement tools and research methodological tasks. In addition, in Korea, where the preparation of a super-aged society should be benchmarked from advanced countries, attention should also be paid to the feasibility review, including the characteristics and functions of the physical activity evaluation tool. The purpose of this study is to identify the characteristics and recent trends of research papers that measure and evaluate physical activity using accelerometers for the elderly, and to introduce the structure and validity of Japan's representative accelerometer and physical activity indicators. The study is meaningful in providing useful basic data for explaining follow-up research tasks related to the evaluation of physical activity for healthy longevity of the elderly in Korea, which is about to become a super-aged society in 2025.

거총부터 격발까지 총구 움직임의 궤적을 추적하여, 사격의 정확성을 향상시킬 목적으로 광전자 기반 사격 훈련 시스템이 사격 훈련 현장에서 활용되어 왔다. 광전자 기반 시스템은 설치가 복잡하고, 표적의 파손 위험이 존재하며, 고가의 장비로 선수들의 접근성이 떨어진다는 단점이 있다. 이에 본 연구는 저비용의 가속도 센서 모듈을 이용하여 체 위 떨림을 측정하고 피드백할 수 있는 사격 훈련 시스템을 개발하고, 이의 활용성을 검증하였다. 가속도 센서 모듈은 총기의 에어 실린더에 부착할 수 있도록 제작되었다. 체위 떨림은 가속도 센서 데이터를 이용하여 진폭, 주파수, 공간적 패턴 지표로서 분석되었다. 가속도 센서와 기존의 광전자 기반 시스템에서 측정된 사격시 체위 떨림 진폭 지표 간에는 높은 상관관계(좌우 방향: r=0.76; 상하 방향: r=0.70)가 나타났다. 또한, 사격 선수를 대상으로 진행한 시스템의 유효 성 평가에서는 선수의 사격 점수(최상, 최하 격발)에 따라 계산된 체위 떨림 지표가 유의한 차이(p<0.05)가 있음을 독립 표본 t-검증을 이용하여 검증하였다.

Optoelectronic shooting training systems are used in shooting training sites to improve the accuracy of shooting by tracking the trajectories of gun movements. However, optoelectronic-based systems have limitations in terms of cost, complexity of installation, and the risk that electronic targets may be broken. In this study, we developed and verified a shooting training system that measures postural tremors using a low-cost accelerometer. The acceleration sensor module was designed to be attached to the air cylinder of a gun. Postural tremors were evaluated based on amplitude, frequency, and spatial pattern index, which were computed using acceleration data. The postural tremor indices between the accelerometer and optoelectronic-based system were highly correlated (left-right and up-down directions: r = 0.76 and r = 0.70, respectively). We validated the developed shooting training system using an independent two-sample t-test, which identified a significant difference (p < 0.05) in the calculated postural tremor index according to the athlete's shooting score (i.e., best and worst shots).

The ability of being able communicate in English is one of the core abilities to be reared for the students whohave to live in the modern society. English is one of the important languages of today. In order to learn suchEnglish, the most basic words and idioms need to be learned first. According to the previous studies, In theelementary school, students tend to lose their interest and affection about English as they move up the grades. However, In recent, 62% of th elementary school students have a smart phone and the main function used by58% among them is games. Due to these reasons, Interrest in learning smartphone game has been increasing. thisstudy intends to design and implementation the educative games for the learning of English idioms on smartphone so that the students can get interest and fun. The English idioms educating game which shall be produced in this study not only is easy and fun to beplayed by the learner but also made it possible for the English idioms learning not to be boring by adding fun andgiving motivations through competitions among the learners by making each obtainments of alphabets of eachEnglish idioms into points. In order to induce the repetitive learning of the learners, the lesson menu was used toallow the English idiom repetition lesson. Also, the acceleration sensor of the smart phone was utilized toproduce this game so that the game is played fluidly and conveniently.

Advancements in sensor technology, particularly Inertial Measurement Units (IMU), are crucial in modern pose estimation. IMUs typically consist of accelerometers and gyroscopes (6-axis), with some models including magnetometers (9-axis). This study investigates the impact of sensor frequency on pose estimation accuracy using data from a 256Hz IMU sensor. The data sets analyzed include “spiralStairs,” “stairsAndCorridor,” and “straightLine,” with frequencies varied to 128Hz, 64Hz, and 32Hz, and conditions categorized as stationary or dynamic. The results indicate that sensitivity remains high at lower frequencies under stationary conditions but declines in dynamic conditions. Performance comparison, based on Root Mean Square Error (RMSE) values, showed that lower frequencies lead to increased RMSE, thus diminishing model accuracy. Additionally, the Extended Kalman Filter (EKF) was tested as an alternative to Madgwick's algorithm but faced challenges due to insufficient sensor noise data.

오토바이의 윙커(방향지시등)는 승용차와 달리 주행 시 방향지시등 레버의 자동 리턴 기능이 불가능하여 회전 주행 완료 후 운전자가 수동으로 윙커스위치를 오프(OFF) 조작해야 하므로 운전자의 편의성 및 안전 주행 에 문제가 있다. 본 논문에서는 윙커스위치 조작 없이 자동으로 이륜차의 윙커 점멸 기능을 제어할 수 있는 새로 운 방식의 이륜차용 윙커 리턴 시스템을 제안한다. 교차로 회전 또는 차선 변경의 경우에 윙커스위치의 방향 전환 신호 조작 후 회전이 완료되면 승용차와 같이 윙커 스위치의 점멸 동작이 완료되는 자동 리턴 기능을 구현하였다. 제안된 제어 시스템을 오토바이 실차에 장착 및 테스트하여 이륜차용 윙커 자동 리턴 기능을 확인하였다.

Contrary to passenger cars, the winker of a motorcycle does not have an automatic return function of the turn signal lever. So the driver must manually turn the winker switch off after making turns which causes problems with the driver’s convenience and safe driving. In this paper, we propose a new type of winker control system for motorcycles that can automatically control the winker returning function without operating the winker switch manually. The system was implemented to control the blinking operation as in a passenger car in the case of intersection turn or lane change without manipulating the direction change signal with the winker switch. The proposed control system was installed and tested on a motorcycle to confirm the automatic winker return feature.

연구목적: 본 논문은 밸브의 누수 상태를 확인하기 위한 모니터링 시스템을 위하여 개발된 스마트 볼트의 적용성에 대한 기초 연구이다. 연구방법: 스마트 볼트에 내장된 변형률 센서와 가속도 센서를 이용하여 모의 누수 탐지 실험을 실시하였다. 연구결과: 스마트 볼트는 볼트 조임토크 기준에 부합하였으며 허용인 장응력 범위 내에서 거동을 하여 상수도 체결부 적용에 부합되는 것으로 나타났다. 그리고 모의 누수 실험 결과 밸브 누수 지점에선 60Hz 대역의 누수 신호가 탐지 되었으며, 메인관 누수에서는 상대적으로 고주 파수 대역의 누수 신호도 탐지되었다. 결론: 모의 배관이 구속되지 않은 상태에서 전체적으로 연성진동이 이뤄진 것으로 보인다. 스마트 볼트를 통해 밸브 누수 신호의 감지에 대한 가능성을 확인하였다.

Purpose: This paper is a fundamental study on the applicability of the smart bolt developed for monitoring system to detect the leakage of water supply valve. Method: A leak detection experiments were conducted using the smart bolt having embedded strain sensors and accelerometer. The smart bolt used in study meets the allowable criteria of torque and tensile stress for water supply system, and it can be applied to a joint of the water supply valve by behaving well within the allowable limits. Result: As a result of the simulated leak tests, a leak signal at the valve leak point was detected in a band of 60Hz, and the main pipe leaking point was observed to produce a leak signal having much higher frequency than that of the valve leak point. This seems to result in a total coupled vibration under unconfined conditions of the pipes. Conclusion: The smart bolts appeared applicable to detecting a leaking signal from the water supply valve.

본 연구의 목적은 마비측 다리에 나선형 방향으로 테이핑을 적용하여 뇌졸중 환자의 보행능력에 미치는 즉각적인 효과를 알아보고자 하였다. 뇌졸중 환자 42명을 각각 실험군(나선형 테이핑군) 21명과 대조군(넙다리네갈래근 테이핑군)21 명으로 나누어 테이핑을 부착하였다. 두 집단 모두 10m 보행 검사(10 meter walk test)와 동적 보행 지수(Dynamic Gait Index; DGI), 가속도계(Accelerometer)를 이용한 시⋅공간적 보행변수 중 보행율(cadence), 속도(speed), 마비측 보행주 기(gait cycle duration), 마비측 디딤기(stance phase duration), 마비측 양발 지기기(double support duration)를 측정 하였다. 연구 결과 중재 전과 중재 후 두 집단 모두 10m 보행과 DGI 그리고 보행율, 보행속도에서 유의한 증가를 보였고 마비측 디딤기, 마비측 보행주기, 마비측 양발지지기에서 증가 및 감소하였지만 유의한 차이가 없었다. 두 집단간 변화량 차이는 유의한 차이가 없었다. 테이핑을 통한 뇌졸중 환자의 보행능력 변화에서 두 방법 모두 보행능력에 증가함을 알 수 있었다. 하지만 나선형 테이핑은 테이핑 절단 횟수가 적고 비교적 쉽게 적용이 가능하므로 가정에서 적용 시 보다 쉽게 적용할 수 있는 방법일 것이다.

The purpose of this study is to examine the immediate effects of spiral taping applied to an affected leg on gait ability in stroke patients. Forty two stroke patients were divided into a spiral taping group (n=21) and a quadriceps femoris group (n=21), and each taping method was applied. Spatiotemporal Gait Parameters (Cadence, speed, gait cycle duration, stance phase duration, double support duration) were measured using the 10-meter walk test, the dynamic gait index (DGI) and an accelerometer for both groups. Both groups showed a significant increase in a 10-minute walk, the DGI, cadence, speed before and after the intervention, whereas no significant difference was detected in stance phase duration, gait cycle duration and double support duration on the affected side in all groups. All groups revealed no significant difference in variation. It has been found that the two taping methods augment gait ability in patients with stroke. This study suggests that spiral taping can be an easily applicable method at home.

이 연구는 초등학교 고학년을 대상으로 동작가속도계를 이용하여 비만아동과 정상체중아동의 신체활동량 및 신 체활동 강도를 측정, 비교 분석하고 신체활동량과 아동비만과의 관계를 알아보는데 목적이 있다. 이를 위하여 강 원도에 위치한 A초등학교 고학년 59명을 대상으로 동작가속도계를 이용하여 4일 동안(목, 금, 토, 일) 평상시 신 체활동량을 측정하였다. 수집된 자료는 SPSS 18.0 프로그램을 이용하여 주중과 주말에 따른 비만아동과 정상체중 아동의 신체활동량 차이 및 상관관계를 파악하기 위해 t-test와 양류상관분석을 실시하였으며, 다음과 같은 결과를 얻었다. 첫째, 성별에 따른 신체활동량은 남학생이 여학생보다 신체활동량(스텝수, 칼로리, 카운트)이 많은 것으로 나타났다. 신체활동 강도의 경우, 남학생은 중강도 활동이 많고, 여학생은 저강도 활동이 많은 것으로 나타났다. 주중, 주말의 비교에서는 주중이 주말에 비해 신체활동량(스텝수, 칼로리, 카운트)이 많은 것으로 나타났다. 신체 활동 강도는 주중이 중강도 활동이 많고, 주말에는 저강도 활동이 많은 것으로 나타났다. 둘째, 비만아동과 정상 체중아동에 따른 신체활동량은 정상체중아동이 비만아동에 비해 신체활동량(스텝수, 카운트)이 많은 것으로 나타 났다. 신체활동 강도에서는 비만아동은 저강도 활동이 많았으며 정상체중아동은 중강도 활동이 많았다. 주중, 주 말의 비교에서는 비만아동과 정상체중아동 모두 주중에 신체활동량(스텝수, 칼로리, 카운트)이 많은 것으로 나타 났다. 신체활동 강도에서는 비만아동과 정상체중아동 모두 주중에는 중강도 활동이, 주말에는 저강도 활동이 많 았다. 결론적으로 초등학생의 신체활동량은 성별과 비만유무에 따라 주중과 주말에 차이가 있다. 여학생보다는 남학생의 신체활동량이 높으며, 주말보다는 주중의 신체활동량이 많다. 특히 남녀 모두 주중 신체활동량과 비만 의 관계가 높은 것으로 확인되었다. 따라서 아동들이 학교생활을 하는 평상시 활동 프로그램 개발 및 여학생 및 비만 아동들을 위한 다양한 후속 연구들이 필요할 것으로 사료된다.

The purpose of this study measured physical activity and intensity of physical activity for mormal weight and obesity elementary 5th and 6th graders with accelerometer, determine the relationship between physical activity and obesity. In order to achieve the purpose of this study, 59 elementary school students living in Gangwondo was a population sampled. This study classified and evaluated the record of accelerometer for 4 days(weekday and weekend). The results is as follows. At first, physical activity of male students was more than female students. Male students did moderate intensity activity mainly but female students did low intensity activity mainly. Comparative study on physical activity by weekdays and weekend, physical activity on weekdays was more than weekend. Secondly, physical activity of normal weight students was more than obese students. In intensity of physical activity, obese students did low intensity activity mainly and normal weight students did moderate intensity activity mainly. Comparative study on physical activity by weekdays and weekend, physical activity of both students on weekdays was more than weekend. In conclusion, there were differences among the amount of physical activity of elementary students on weekdays and weekend depending on gender and weight(normal and obesity). So various studies and programs will have to be developed for enhancement of physical activity of obese students.

Stroke incidence is increasing accordance with the aging of the population. While stroke patients increases the survival rate due to the contemporary development of medicine, goes on increasing the chronic disease by muscle impairment called hemiplegia. Rehabilitation training of motor skills for hemiplegia patients comprises repetitive and passive contents. In this paper, we developed a movement recognition device using acceleration sensor to help the upper limb rehabilitation and functional game contents in order to reduce the boredom of rehabilitation. By this contents, we can be maximized effect of the exercise using rehabilitation training contents made by simple graphical resources and added fun. Later on, we will provide various contents that can use several platform interface and can be have a lot of fun exercise and spread the range of applications of functional game contents.

목적 : 본 연구는 정상 성인을 대상으로 일상생활활동 수행하는 동안 기존의 삼차원동작분석 장비와 가속도 계에서 발생하는 변수를 동시에 측정하여, 기존의 삼차원동작분석 장비와 가속도계에서 측정된 값의 상 관관계를 파악하고 가속도계의 활용 가능성을 제시하고자 하였다. 연구방법 : 성인 20명(남자 10명, 여자 10명)을 대상으로 전화하기, 물 마시기, 세수하기, 숟가락 사용하기를 수행하는 동안 피트미터(Model Fitmeter, Fit.Life, Korea)와 CMS-70P(Zebris Medizintechnik Gmbh, Germany)를 사용하여, 손목 관절과 팔꿉 관절에서 단일벡터크기(Signal Vector Magnitude: SVM) 합과 관절가동범위를 측정하였다. 결과 : 전화하기, 물 마시기, 세수하기, 숟가락 사용하기 수행 시 손목과 팔꿈치에서 발생하는 관절가동범위 와 단일벡터크기 합은 과제에 따라 유의한 차이가 있었다(p<.001; p<.001; p<.001; p<.001). 관절가동범위 와 단일벡터크기 합은 손목에서는 유의한 상관관계를 보이지 않았으나(p>.05), 팔꿈치에서는 유의한 상관 관계를 보였다(p<.01; p<.001; p<.01; p<.05). 손목과 팔꿈치에서 발생하는 단일벡터크기 합의 차이는 전 화하기와 세수하기는 손목과 팔꿈치에서 유의한 차이를 보였으나(p<.001; p<.05), 물 마시기와 숟가락 사 용하기는 손목과 팔꿈치에서 유의한 차이를 보이지 않았다(p>.05; p>.05). 결론 : 가속도계는 일상생활활동의 역학적 변수를 측정할 때 유용하게 사용할 수 있을 것으로 생각되며, 손 목보다는 팔꿈치에서 가속도계가 삼차원동작분석 장비의 기능을 대체할 수 있을 것으로 사료된다.

Objective : The objectives of this study were to compare the variables from Fitmeter accelerometer with them from CMS-70P(Zebris Medizintechnik Gmbh, Germany) and to suggest the availability the accelerometer in the field of occupational therapy. Methods : Twenty participants performed calling, drinking water, washing face and spooning and we measured Sum of Single Vector Magnitude(SSVM) and range of motion(ROM) on the wrist and elbow joints. Results :With respect to the wrist and elbow joints, SSVM and ROM differed significantly according to the task(calling, drinking water, washing face and spooning)(p<.001; p<.001; p<.001; p<.001). As for the wrist joint, SSVM and ROM did not show the significant correlation(p>.05) but as for the elbow joint, SSVM and ROM did show the significant correlation according to the task(p<.01; p<.001; p<.01; p<.05). With regard to the SVM -difference of wrist and elbow joints, calling and washing showed the significant difference (p<.001; p<.05) but drinking and spooning did not show the significant difference(p>.05; p>.05). Conclusion : We suggest that Fitmeter accelerometer would be use to record the kinematic variables during performance of ADL and it can compensate the function of CMS-70P as for the elbow joint than the wrist joint.

This experimental work provides the method to detect damage of four-story steel structure model based on FRF (frequency response function) data collected from impact hammer tests. This method does not require the baseline data at the intact state without damage. The measurements at two states depending on the mass attachment are collected. The collected data are transformed to POM (proper orthogonal mode) and the damage is investigated through the comparison of two POM sets. The experimental work illustrates the validity and applicability of the proposed method.

보행자의 위치 추정은 노약자 및 장애인을 돕기 위한 필수 기술이며, GPS 신호를 받을 수 없는 지역에서 일하는 응급구조인력에게도 매우 중요한 기술이다. 실내 환경에서의 위치추정은 주행로봇분야에서 활발히 연구되고 있으 며, 가장 널리 사용되는 방법은 내부 인코더센서와 카메라, 가속도계등의 외부 센서정보를 활용하는 방법이다. 그 러나 보행자에게는 인코더와 같은 내부 센서가 없으므로 주행로봇의 경우와는 다른 방법이 필요하다. 이 논문에서 는 각속도계를 사용한 보행자 위치추정 방법에 대하여 기술한다. 가속도계 대신 각속도계를 사용하여 보행자의 걸 음걸이를 추정하였고, 이로부터 보행거리를 계산하였다. 보행자의 위치를 추정하기 위하여 필요한 정보인 방향각 은 각속도계와 지자기센서 정보를 융합하여 구하였고, 또한 각속도계의 편류오차를 줄이는 방법을 제안하였다.

Pedestrian localization is the key technology for caring the elderly, the visually impaired and the handicapped in health care districts. It also becomes essential for the emergency responders where the GPS signal is not available. Indoor localization has been studied for mobile robots. One of the localization methods is using the internal encoder sensors and extra sensors such as the camera, the accelerometer, etc. However, it can not be applied to the localization of the pedestrian because the pedestrians do not have the dead reckoning sensors and may move differently from the mobile robot. This paper presents newly developed pedestrian localization system using the gyro sensors. Instead of using the accelerometer, the pedestrian gait is estimated from the gyro sensor measurement and the travel distance is estimated based on the gait kinematics. New method of fusing the gyro information and the magnetic compass information is developed and used in the proposed localization.

Many wearable devices include PPG (photoplethysmography) sensors for non-invasive heart rate monitoring. However, PPG signals are heavily corrupted by motion interference, and rely on simultaneous motion measurements to remove the interference. Accelerometers are used commonly, but cannot differentiate between acceleration due to movement and acceleration due to gravity. This paper compares measurements of motion using accelerometers and gyroscopes to give a more complete estimate of wrist motion. Results show the two sensor signals are very different, with low correlations present. When used in a wrist PPG heart rate algorithm gyroscope motion estimates obtain better performance in half of the cases.

Horse breeders suffer massive economic losses due to dystocia, abortion, and stillbirths. In Thoroughbred mares, breeders often miss the foaling process because approximately 86% of the foaling events occur from 19:00 to 7:00; consequently, breeders cannot assist mares experiencing dystocia. To solve this problem, various foaling alarm systems have been developed. However, there is a need to develop a new system to overcome the shortcomings of the existing devices and improve their accuracy. To this end, the present study aimed to (1) develop a novel foaling alarm system and (2) compare its accuracy with that of the existing Foalert™ system. Specifically, eighteen Thoroughbred mares (11.9 ± 4.0 years old) were included. An accelerometer was used to analyze specific foaling behaviors. Behavioral data were transmitted to a data server every second. Depending on the acceleration value, behaviors were automatically classified by the server as categorized behaviors 1 (behaviors without change in body rotation), 2 (behaviors with sudden change in body rotation, such as rolling over), and 3 (behaviors with long-term change in body rotation, such as lying down laterally). The system was designed to alarm when the duration of categorized behaviors 2 and 3 was 12.9% and that of categorized behavior 3 was 1% during 10 min. The system measured the duration of each categorized behavior every 10 min and transmitted an alarm to the breeders when foaling was detected. To confirm its accuracy, the foaling detection time of the novel system was compared with that of Foalert™. The novel foaling alarm system and Foalert™ alarmed foaling onset respectively 32.6 ± 17.9 and 8.6 ± 1.0 min prior to foal discharge, and the foaling detection rate of both systems was 94.4%. Therefore, the novel foaling alarm system equipped with an accelerometer can precisely detect and alert foaling onset.