• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.319-341
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• 2016

Objective:This research analyzed the lower-limb motion in kinetic and kinematic way while walking on various terrains to develop Foot-Ground Contact Detection (FGCD) algorithm using the Inertial Measurement Unit (IMU). Background: To estimate the location of human in GPS-denied environments, it is well known that the lower-limb kinematics based on IMU sensors, and pressure insoles are very useful. IMU is mainly used to solve the lower-limb kinematics, and pressure insole are mainly used to detect the foot-ground contacts in stance phase. However, the use of multiple sensors are not desirable in most cases. Therefore, only IMU based FGCD can be an efficient method. Method: Orientation and acceleration of lower-limb of 10 participants were measured using IMU while walking on flat ground, ascending and descending slope and stairs. And the inertial information showing significant changes at the Heel strike (HS), Full contact (FC), Heel off (HO) and Toe off (TO) was analyzed. Results: The results confirm that pitch angle, rate of pitch angle of foot and shank, and acceleration in x, z directions of the foot are useful in detecting the four different contacts in five different walking terrain. Conclusion: IMU based FGCD Algorithm considering all walking terrain possible in daily life was successfully developed based on all IMU output signals showing significant changes at the four steps of stance phase. Application: The information of the contact between foot and ground can be used for solving lower-limb kinematics to estimating an individual's location and walking speed.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.141-149
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• 2013

This paper presents a high-speed intrusion detection process for multi-core video surveillance systems. The high-speed intrusion detection was designed to a parallel process. Based on the analysis of the conventional process, a parallel intrusion detection process was proposed so as to be accelerated by utilizing multiple processing cores in contemporary computing systems. The proposed process performs the intrusion detection in a per-frame parallel manner, considering the data dependency between frames. The proposed process was validated by implementing a multi-threaded intrusion detection program. For the system having eight processing cores, the detection speed of the proposed program is higher than that of the conventional one by up to 353.76% in terms of the frame rate.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.113-118
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• 2020

Due to the rapid increase in cyber shopping mall of agricultural products, the parcel delivery service industry also increased, making it necessary to design an optimum packaging for agricultural products. And Due to the recent increase in strawberry consumption, there is also a need for a packaging system for parcel delivery service. In order to establish the criteria for optimum cushioning packaging design of strawberries, the bioyield strength of strawberries by storage time was measured through the ASABE test standards, and the peak acceleration in the resonance frequency and resonance frequency bands of strawberries was measured through the vibration test regulated in the ASTM test specifications. Tray cup pad and corrugated fiberboard box of delivery strawberries were designed using FEM theoretical analysis of contact stress and resonant frequency. In addition, an optimum packaging system was developed with a cushioning and vibration design considering the impact characteristics when distributing agricultural products. Through the performance evaluation and on-site evaluation of the optimum packaging system of strawberries for parcel delivery service, the random PSD test results of the delivery showed a 74% reduction in the acceleration level, and the actual distribution test of the delivery showed that the damage rate of strawberries was not more than 6.7%, indicating that it was possible to use the optimum packaging of strawberries for delivery.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.165-177
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• 2012

PURPOSES: The number of traffic accidents in 2010 was 226,978 in Korea, a high percentage of which up to 12.61% was due to drunk driving. As it is expected that the number of traffic accidents will increase because of the drastic increase of the number of vehicle registrations and the prevalent drinking cultures, it is necessary to understand the driving characteristics of drunken drivers to lower the increasing rate. METHODS: This study, therefore, comparatively analyzes the two groups - one group before drinking and the other after drinking - based on the graph, and implements the correlation in each scenario(1,2,3). scenario 1. appearance of jaywalkers; scenario 2. appearance of an illegal left-turning car; and scenario 3. appearance of a vehicle and a person as obstacles to the driver after an accident. RESULTS: The comparative analysis of speed shows that the group after drinking was 50km/h faster than the group before drinking in Scenario 1, 20km/h in Scenario 2, and 15km/h in Scenario 3 respectively. In the comparative analysis of acceleration, the average level of the group after drinking was 0.15 higher than that of the group before drinking in Scenario 1, 0.30 in Scenario 2, and 0.15 in Scenario 3. In the comparative analysis of deceleration, the average level of the group after drinking was about 0.4 lower than that of the group before drinking in Scenario 1, 0.35 in Scenario 2, and 0.2 in Scenario 3 respectively. In the comparative analyses, the item of speed, acceleration and deceleration was of significance for each group in Scenarios. CONCLUSIONS: The comparative analysis demonstrated that there is a difference between the group before drinking and the group after drinking. In the analysis of correlation in each group, it was proved that the drunken group was of significance.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.81-92
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• 2011

In order to understand evaluation of the seismic stability of a fill dam, we made chambers of 1:100, 1:70, and 1:50 (the ratio of the miniature), considering the law of similarity based on drawings of three representative cross sections. And we measured an increase in acceleration, excess pore water pressure, and vertical/horizontal displacement after applying Hachinohe wave (long period), Ofunato wave (short period), and artificial wave, complying with the domestic standards, in order to evaluate the stability and interaction between the ground, the structure, and fluids based on the measurements. As a result, we could observe that displacement of the target cross section was relatively small compared to the allowed level of 30 cm, ensuring proper stability for an earthquake. Regarding the acceleration measurements, the increase rate was 20% for Hachinohe wave and Ofunato wave but 30% for the artificial wave. With respect to the excess pore water pressure, it was lower than 1 (which is the permissible ratio for liquefaction) ensuring proper stability as well.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.510-516
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• 1993

This study was conducted to investigate biochemical characteristics of enzyme-added cheese base slurries during accelerated ripening. Trichloroacetic acid (TCA) soluble nitrogen of cheese base slurries increased rapidly during the first day of ripening and the rate of increase slowed down thereafter. Cheese base slurries showed lower level in the production of the nitrogen than Cheddar cheese slurries. Producctions of phosphotungstic (PTA) soluble amino nitrogen also showed similar trends as TCA soluble nitrogen. Electrophoresis revealed that all caseins in both cheese base slurries and Cheddar cheese slurries were hydrolyzed, but whey proteins in cheese base slurries were little hydrolyzed. Cheese base slurries produced free amino acids little more than half of Cheddar cheese slurries. Both slurries showed similar increasing trend in production of short-chain free fatty acids. The specificity of the fatty acids in the slurries was similar to that of natural ripened cheese. The results of this study showed that addition of enzyme was effective to accelerate cheese base ripening.

• 연구논문집
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• s.30
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• pp.101-110
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• 2000

Weft insertion mechanism is for completing the structure of yarn and weft yarn and its driving method is screw type. In the high speed rapier loom, weft yarn is thrown by insert rapier and carrier rapier into the shed which make divide two parts of upper part ant lower part for warp yarn. It is possible for this mechannism to reduce the size of rapier and wheel, and directly connected to the main shaft without gear belt. Therefore, exact rapier motion through realization of arbitrary acceleration diagram requested rapier and optimal design for high speedization and operating rate increasing are necessary. In this study, with a view to exact system analysis for understanding of overall trace and high speedization of rapier loom through computer simulation. we report not only deduction of displacement, velocity, and acceleration components of rapier for analysis theory establishment, of weft insertion mechanism and exact motion induction according to screw rotation, but also development of simulation program for realization these on the monitor.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1159-1166
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• 2017

Cattle behavior detection system based on Internet of Things is designed and implemented by using gyroscope and acceleration sensor, Arduino pro-mini and bluetooth module. The implemented system measures cattle's moving and the measured data are transmitted to smart phone by bluetooth module. They are displayed by 2-dimensional graph on the smart phone and the number of cattle's step are calculated from the graph. The detected and gathered data from the system are analyzed by the proposed algorithm to decide which cows are in the estrus or not, and the proposed system can be used to increase the success rate of artificial insemination in normal estrus by detecting cow's behaviors such as the number of steps and jumping. In this paper, the implemented cattle behavior detecting system are strapped on cattle's leg and it measures cattle behaviors for determining that a cattle is estrus or not by the proposed algorithm. In the future research, the system which lengthens communication distance and increases the number of cattle under the test will be considered and also the measured data will be database for cattle research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1725-1730
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• 2017

The acceleration sensor and the gyroscopic sensor are used as representative sensors to detect repetitive motion and have been used to analyze various sporting components. However, both sensors have problems with noise sensitivity and accumulation of errors. There have been attempts to use two sensors together to overcome hardware problems. The complementary filter has shown successful results in mitigating the problems of both sensors by minimizing the disadvantages of accelerometer and gyroscope sensors and maximizing their advantages. In this paper, we proposed a modified method using neural network to reduce variable. The neural network is an algorithm that can precisely measure even in unexpected environments or situations by pre-learning the number of various cases. The proposed method applies a Neural Network by dividing the repetitive motion into three sections, the first, the middle and the end. As a result, the recognition rate is 96.35%, 98.77%, 96.92% and the accuracy is 97.18%.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.401-407
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• 2021

The continuous active sonar technology is effective for detecting and tracking targets because of short target revisiting rate. Generalized Sinusoidal Frequency Modulation (GSFM) pulses suitable for continuous active sonar systems are known to be capable of obtaining high time-bandwidth product while maintaining the orthogonality between pulses. However, it is unknown how to calculate an appropriate length of time to correlate received GSFM pulses in the presence of a target with acceleration. In this paper, we propose a method to calculate the appropriate time length based on the correlation when matching the received signal in the continuous active sonar system using GSFM pulse. The proposed method calculates the correlation according to the acceleration of the target and calculates the signal processing length according to the correlation. It is shown that stable detection performance can be obtained when the signal processing length calculated by the proposed method through the level of the sidelobe is applied.