• The Korean Journal of Rehabilitation Nursing
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• v.7 no.1
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• pp.48-57
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• 2004

Introduction : The purposes of this study was to examine physical function and psychological status in the elderly caused by a fall. Method : The study was designed as a descriptive survey. Its subjects consisted of the 299 elderly over 65 years. Collected data were analyzed by the SPSS 10.0 program package. Results : The result of this study are as follows : 1) The score for ADL was significantly lower in the fall group. 2) Grip strength was significantly lower in the fall group. 3) Lapse of the motion sitting and standing was significantly longer in the fall group. 4) One-leg-standing time with the eyes open and closed was significantly shorter in the fall group. 5) Return time of 3m walk was significantly longer in the fall group. 6) The score for dizziness was significantly higher in the fall group. 7) The score for fear for a fall and depression were significantly higher in the fall group. 8) The score for falls efficacy was significantly lower in the fall group. Conclusion: ADL, muscle strength, balance, dizziness, fear for a fall, falls efficacy and depression turned out to be closely related to the fall of the elderly. Therefore, it would be required to develop and applicate the fall prevention program regarding these above risk factors.

• Journal of Information Technology Services
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• v.11 no.sup
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• pp.113-121
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• 2012

In this study, a real-time fall detection system based on a smartphone equipped with three-axis accelerometer and magnetometer was proposed and evaluated. The proposed system provides a service that detects falls in real time, triggers alarm sound, and sends emergency SMS(Short Message Service) if the alarm is not deactivated within a predefined time. When both of the acceleration magnitude and angle displacement of the smartphone attached to waist belt are greater than predefined thresholds, it is detected as a fall. The proposed system was evaluated against activities of daily living(walking, jogging, sitting down, standing up, ascending stairs, and descending stairs) and unintended falls induced by a proprietary pneumatic-powered mattress. With the thresholds of acceleration magnitude 1.7g and angle displacement $80^{\circ}$, it showed 96.5% accuracy to detect the falls while all the activities of daily living were not detected as fall.

• Physical Therapy Korea
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• v.28 no.1
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• pp.84-91
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• 2021

Background: A hip fracture may occur spontaneously prior to the hip impact, due to the muscle pulling force exceeding the strength of the femur. Objects: We conducted falling experiments with humans to measure the activity of the hip muscles, and to examine how this was affected by the fall type. Methods: Eighteen individuals fell and landed sideways on a mat, by mimicking video-captured real-life older adults' falls. Falling trials were acquired with three fall directions: forward, backward, or sideways, and with three knee positions at the time of hip impact, where the landing side knee was free of constraint, or contacted the mat or the contralateral knee. During falls, the activities of the iliopsoas (Ilio), gluteus medius (Gmed), gluteus maximus (Gmax) and adductor longus (ADDL) muscles were recorded. Outcome variables included the time to onset, activity at the time of hip impact, and timing of the peak activity with respect to the time of hip impact. Results: For Ilio, Gmed, Gmax, and ADDL, respectively, EMG onset averaged 292, 304, 350, and 248 ms after fall initiation. Timing of the peak activity averaged 106, 96, 84, and 180 ms prior to the hip impact, and activity at the time of hip impact averaged 72.3, 45.2, 64.3, and 63.4% of the peak activity. Furthermore, the outcome variables were associated with fall direction and/or knee position in all but the iliopsoas muscle. Conclusion: Our results provide insights on the hip muscle activation during a fall, which may help to understand the potential injury mechanism of the spontaneous hip fracture.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.174-180
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• 2008

The pulsed amplifier which switches the main supply voltage of RF amplifier according to input pulse signal has good efficiency and low noise level between pulses. And it has simple structure because it doesn't need a pulse modulator at input port. The pulsed amplifier using the conventional switching circuit has slow fall time compared to rise time. We proposed the novel switching circuit for improving the fall time of pulsed amplifier The proposed switching circuit is implemented by replacing FET of conventional circuit with BJT. As a result of appling this circuit to RF pulsed amplifier, the rise and fall time are 5.7 ns and 21.9 ns at 27 dBm output power, respectively.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.9-16
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• 2007

The purpose of this study was to analyze the effects of after aquatic exercise on gait in the Falls Experienced elderly. There were one group : Fall Experienced Elderly Women(n=8). They were tested on their gait (Elapse time of each phase, Stance time of limb, Stride length, Velocity of segment). we took video and analyzed their movement using Ariel Performance Analysis System and compared gait parameters. For data analysis, mean and standard deviation scores were calculated, and correspondence sample t-test and pearson's correlation analysis were used. First, after exercise is short than before exercise on Elapse time of each phase, fall-experience subjects showed meaningful total time. Second, after exercise is short than before exercise on Stance time of limb and Stride length, fall-experience subjects showed meaningful Stride length. Third, after exercise is fast than before exercise on Velocity of segment.

• Journal of KIISE
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• v.42 no.3
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• pp.281-288
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• 2015

A volcano disaster damage prediction system supports decision making for counteracting volcanic disasters by simulating meteorological condition and volcanic eruptions. In this system, a program called Fall3D generates predicted results for the diffusion of ash after a volcanic eruption on the basis of meteorological information. The relevant meteorological information is generated by a weather numerical prediction model known as Weather Research & Forecasting (WRF). In order to reduce the entire processing time without modifying these two simulation programs, pipelining can be used by partly executing Fall3D whenever the hourly (partial) results of WRF are generated. To reduce the processing time, successor programs such as Fall3D require that certain features be suspended until the part of the results that is based on prior calculation is generated by a predecessor. Even though Fall3D does not have a suspend or resume feature, pipelining effect can be produced by using the program's restart feature, which resumes simulation from the previous session. In this study, we suggest a workflow that can control the execution type.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.2987-3002
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• 2023

In 2015, the number of senior citizens aged 65 and over in Korea was 6,662,400, accounting for 13.1% of the total population. Along with these social phenomena, risk information related to the elderly is increasing every year. In particular, a fall accident caused by a fall can cause serious injury to an elderly person, so special attention is required. Therefore, in this paper, we implemented a system that monitors fall accidents and informs them in real time to minimize damage caused by falls. To this end, beacon-based indoor location positioning was performed and biometric information based on an integrated module was collected using various sensors. In other words, a multi-functional sensor integration module was designed based on Arduino to collect and monitor user's temperature, heart rate, and motion data in real time. Finally, through the analysis and prediction of measurement signals from the integrated module, damage from fall accidents can be reduced and rapid emergency treatment is possible. Through this, it is possible to reduce the damage caused by a fall accident, and rapid emergency treatment will be possible. In addition, it is expected to lead a new paradigm of safety systems through expansion and application to socially vulnerable groups.

• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.286-292
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• 2020

This paper is about a fall inducement system for guiding like a real fall. Reliable fall data can be used as an essential element in developing effective fall protection devices. We can get this data if the induced fall is very realistic. The proposed system analyzes gait characteristics and determines when to fall based on the pedestrian's biometric data. To estimate the fall inducement time, an active estimation algorithm was proposed using different biometric values for each pedestrian. The proposed algorithm is designed to response actively to the ratio of gait cycle and a stance period. To verify this system, an experimental environment was implemented using a multi-rail treadmill equipped with a ground reaction force measurement device. An experiment was conducted to induce falls to pedestrians using a fall inducement system. By comparing the experimental scene to the video of the actual fall, it has been confirmed that the proposed system can induce a reliable fall.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.552-554
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• 2021

We propose a fall recognition system using a deep learning algorithm using motion data acquired by a Doppler radar sensor. Among the deep learning algorithms, an RNN that has an advantage in time series data is used to recognize falls. The fall data of the Doppler radar sensor has a temporal characteristic as time series data, and the structure of the RNN is sequenced because the result only determines whether a fall or not It is designed in a structure that outputs a fixed size to the input.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.8
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• pp.22-29
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• 2007

A 2.5Gb/s 2:1 multiplexer(MUX) IC using $0.18{\mu}m$ CMOS was designed and fabricated. Inductive peaking technology was used to improve the performance. On-chip micro spiral inductor was designed to maximize the inductive peaking effect without increasing the chip area much. The designed 4.7 nH micro-spiral inductor was $20\times20{\mu}m2$ in size. 2:1 MUX with and without micro spiral inductors were compared. The rise and fall time was improved more than 23% and 3% respectively using the micro spiral inductors for 1.25Gb/s signal. For 2.5 Gb/s signal, fall and rise time was improved 5.3% and 3.5% respectively. It consumed 61mW and voltage output swing was 1$180mV_{p-p}$ at 2.5Gb/s.