• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.243-248
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• 2015

U-Healthcare is a convergence service with medical care and IT which enables to examine, manage and maintain the patient's health any time and any place. For communication conducted in U-Healthcare service, the transmission methods are used that patient's medical checkup analysis results or emergency data are transmitted to hospital server using wireless communication method. At this moment when the attacker who executes the malicious access makes DRDoS(Distributed Reflection DoS) attack to U-Healthcare devices or BS(Base Station), various damages occur that contextual information of urgent patients are not transmitted to hospital server. In order to deal with this problem, this study suggests DRDoS attack scenario and countermeasures against DRDoS and converges with Big Data which could process large amount of packets. When the attacker attacks U-Healthcare devices or BS(Base Station), DB is interconnected and the attack is prevented if it is coincident. This study analyzes the attack method that could occur in U-Healthcare devices or BS which are remote medical service and suggests countermeasures against the security threat using Big Data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.77-87
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• 2018

Traffic Density is the most important of the three primary macroscopic traffic stream parameters, because it is most directly related to traffic demand(Traffic Engineering, 2004). It is defined as the number of existing vehicles within a given distance at a certain time. However, due to weather, road conditions, and cost issues, collecting density directly on the field is difficult. This makes studies of density less actively than those of traffic volume or velocity. For these reasons, there is insufficient attempts on divers collecting methods or researches on the accuracy of measured values. In this paper, we used the 'Density Measuring System' based on the synthesise technology of several camera images as a method to measure density. The collected density value by the 'Density Mesuring System' is selected as the true value based on the density define, and this value was compared with the density calculated by the traditional measurement methods. As a result of the comparison, the density value using the fundamental equation method is the closest to the true value as RMSE shows 1.8 to 2.5. In addition, we investigated some issues that can be overlooked easily such as the collecting interval to be considered on collecting density directly by calculating the moment density and the average density. Despite the actual traffic situation of the experiment site is LOS B, it is difficult to judge the real traffic situation because the moment density values per second are observed max 16.0 (veh/km) to min 2.0 (veh/km). However, the average density measured for 15 minutes at 30-second intervals was 8.3-7.9 (veh/km) and it indicates precisely LOS B.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.125-131
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• 2020

This study sought to reduce the risk of fractures in elite youth taekwondo athletes to find out the relationship between bone mineral density which are used as indicators of early diagnosis of osteoporosis and cardiorespiratory functional capacity which is an indicator of performance and sports injury the harmful to athletes. The Pearson product-moment correlation was performed to investigate the correlation between bone mineral density, cardiorespiratory functional capacity, and sports injury. The bone mineral density and cardiorespiratory functional capacity, sports injury were examined the relationship using the Simple Linear Regression. The bone mineral density were correlated with the ventilation (r=.388), and VO2max (r=.478). Bone mineral density was correlated with sports injury (r=-.292). When the bone mineral density increased by .002 and .006, the ventilation (p=.001) and VO2max (p=.006) increased by about 1. In addition, when the bone mineral density decline by .016, the sports injury increased by about 1. Improving athletes' bone mineral density can prevent sports injury, and it can be used as a sports injury prevention program in the future.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.363-370
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• 2018

This study aims to analyze the impact of motivation through Response-Based Learning (RBL) on elementary students' attitude of participation and change before and after a Physical Education class and provide a perspective on the understanding of the practice of the PE class. For this purpose, this study selected 115 students in fifth grade in N. Elementary School located in the C. region as subjects, regardless of their sex. An exploratory factorial analysis was conducted with the subjects, and they were analyzed, applying a product-moment coefficient to examine the similarity between the factors. As shown in the result of this study, it is necessary to promote student-centered education instead of one-sided cramming education. Also, it is important to consider and convergence on apply the factors of learning before and after the class to be able to contribute to students' active and positive participation in the PE class.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.661-668
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• 2011

Direction estimation of signal of interest has been an important issue in radar and communication system. Generally, DOA(Direction Of Arrival) methods have been researched in the field of signal processing with ideal array sensors. However, there are some problems in array antennas such as the input signal distortions in amplitude and phase, due to the mutual coupling between array elements. In this paper, we propose a new method of DOA estimation in the dipole array antenna by using the method of moment(MoM) to compensate the mutual coupling effects between array antenna elements. Also, the proposed method is applied to the estimation of azimuth(${\phi}$ ) and elevation(${\theta}$) angles using uniformly linear dipole array under noisy environments.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.75-84
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• 2017

The purpose of this study is to find the relation between the detailed categories of the self-efficacy of workers in the field of railroad signaling and the detailed categories of their fatigue in the use of analysis of moment structure(AMOS) model. A self-administered questionnaire survey of workers in the field of railroad signaling had been conducted and a total of 341 copies were analyzed. This study had the assumption that their general self-efficacy and social self-efficacy would negatively influence their physical fatigue and mental fatigue. As a result, their general self-efficacy negatively influenced their physical fatigue and mental fatigue, whereas their social self-efficacy didn't influence their physical fatigue and mental fatigue. Therefore, it is possible to reduce the fatigue of the study subjects by enhancing corporate support to increase their general self-efficacy.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.130-137
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• 2015

In this paper, we propose a new Modified Filtered-x Affine Projection Sign Algorithm(MFxAPSA) to improve the convergence speed of the conventional MFxAPSA which has been proposed for active control of impulsive noise. Under the impulsive noise environment, the adaptive algorithms based on the second order moment such as the Filtered-x Least Mean Square(FxLMS) show slow convergence speed or diverge because the noise source tends to have infinite variance. The MFxAPSA is the algorithm derived by applying the Affine Projection Sign Algorithm(APSA) to active noise control. The APSA has an advantage that it does not need the calculation for the inverse matrix, so it may be suitable for the active noise control that requires low computational burden. The proposed MFxAPSA also has APSA's advantage and furthermore, better performance than the conventional MFxAPSA. We carried out a performance comparison of the proposed MFxAPSA with the conventional MFxAPSA. It is shown that the proposed MFxAPSA has the faster convergence speed than the conventional MFxAPSA.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.225-232
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• 2019

This study aims to compare muscle activities of trunk and lower extremities according to wearing/not-wearing and forms of backpack. Twenti-six healthy adults were participated in the study. In the backpack with 10% body weight, trunk and lower extremities were measured during carrying the no backpack state(NBs), general backpack state(GBs), a decrease moment arm backpack state(DMBs). The muscle activity in a fore muscles(Obilique, Quadriceps, Tibialis anterior, Gastrocnemius) were analyzed with using wireless electromyogram measuring system. DMBs showed significant improvemet in obilique, quadriceps and gastrocnemius muscle RVC.

• The Korean Journal of Food & Health Convergence
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• v.5 no.3
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• pp.35-40
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• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• Journal of Institute of Convergence Technology
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• v.1 no.2
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• pp.6-15
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• 2011

This paper reports the design and fabrication of a micro-electro-mechanical-system(MEMS)-based electrostatic angular microactuator for a dual-stage servo. The proposed actuator employs a novel electrode pattern named "skewed electrode array(SEA)" scheme. It is shown that SEA has better linearity than a parallel plate type actuator and stronger force than a comb-drive based actuator. The moving and the fixed electrodes are arranged to make the driving force perpendicular to the rotating moment of arm. By changing the electrode overlap length, the magnitude of electrostatic force and stable displacement will be changed. In order to optimize the design, an electrostatic FE analysis was carried out and an empirical force model was established for SEA. A new assembly method which will allow the active electrodes to be located beneath the slider was developed. The active electrodes are connected by inner and outer rings lifted on the base substrate, and the inner and outer rings are connected to platform on which the slider locates. Electrostatic force between active electrodes and platform can be used for exiting out of plane modes, so this provides the possibility of the flying height control. A microactuator that can position the pico-slider over ${\pm}0.5{\mu}m$ using under 20 volts for a 2 kHz fine-tracking servo was designed and fabricated using SoG process.