• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.628-630
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• 2005

IPv6는 기존 IPv4의 문제점인 주소 고갈 문제를 근본적으로 해결하기 위해 IETF(Internet Engineering Task Force)에서 제안한 프로토콜이다. 그러나 IPv4를 한 순간에 IPv6로 대체하는 것이 불가능하기 때문에 IPv4와 IPv6간의 호환 및 연동을 위해 듀얼스택(dual stack), 터널링(tunneling), 프로토콜 변환(protocol translation) 등 많은 IPv4-to-IPv6 transition 메커니즘들이 고려되고 있다. 이러한 프로토콜 진화 방안들은 각 방식에 따라 최소한 한 개 이상의 많은 공인 IPv4 주소를 필요로 하며 IPv4 주소가 부족한 현재 상황에서 IPv6 네트워크와의 연동에 않은 어려움이 따르게 된다. 본 논문에서는 공인 IPv4 주소 부족 문제와 네트워크 보안의 필요성에 의해, IPv4 사설 네트워크에서 공인 IPv4주소로 이루어진 네트워크(인터넷)와 IPv6 네트워크의 연동을 위해 단지 하나의 공인 IP 주소를 이용하여 네트워크간의 연동을 지원하는 통합 연동기를 설계한다.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.199-201
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• 2008

In this paper proposed the solar tracking system to use direct fuzzy control order to increase an output of the PV (Photovoltaic) array. The solar tracking system operated two DC motors driving by signal of photo sensor. The control of dual axes is not an easy task due to nonlinear dynamics and unavailability of the parameters. Recently, artificial intelligent control of the fuzzy control, neural-network and genetic algorithm etc. have been studied. The fuzzy control made a nonlinear dynamics to well perform and had a robust and highly efficient characteristic about a parameter variable as well as a nonlinear characteristic. Hence the fuzzy control was used to perform the tracking system after comparing with error values of setting-up, nonlinear altitude and azimuth. In this paper designed a DFC(Direct Fuzzy Control)controller for improving output of PV array and evaluated comparison with efficient of conventional PI controller. The data which were obtained by experiment were able to show a validity of the proposed controller.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.2
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• pp.117-124
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• 2009

Purpose：The purpose of this study was to investigate of the change of the forward head posture(FHP) according to computer using time. Methods：Subjects were 30 male and 30 female. The factors of FHP were measured cranial vertical angle, cranial rotation angle, and head, upper back, neck flexion/extension angle according to computer using time. Change of FHP used to Digital Inclinometry(JTech, Dualer IQTM Dual Inclinometer). The data were collected by data logger(Logger Teknologi HB, Akarp, Sweden). Results：Cranial vertical angle, cranial rotation angle, and head, upper back, neck flexion/extension were increased according to computer using time(p<.05). But cranial vertical angle and cranial rotation angle, and head, upper back, neck flexion/extension were not significant differences between male and female group(p>.05). Conclusion：The effects of cranial vertical angle, cranial rotation angl and head, neck and upper back angle depend on the computer task time. Increased of FHP may result increased tension in posture muscles of cervical spine, resulting in a risk of musculoskeletal disorders.

• Journal of Information Processing Systems
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• v.17 no.4
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• pp.754-771
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• 2021

In the task of continuous dimension emotion recognition, the parts that highlight the emotional expression are not the same in each mode, and the influences of different modes on the emotional state is also different. Therefore, this paper studies the fusion of the two most important modes in emotional recognition (voice and visual expression), and proposes a two-mode dual-modal emotion recognition method combined with the attention mechanism of the improved AlexNet network. After a simple preprocessing of the audio signal and the video signal, respectively, the first step is to use the prior knowledge to realize the extraction of audio characteristics. Then, facial expression features are extracted by the improved AlexNet network. Finally, the multimodal attention mechanism is used to fuse facial expression features and audio features, and the improved loss function is used to optimize the modal missing problem, so as to improve the robustness of the model and the performance of emotion recognition. The experimental results show that the concordance coefficient of the proposed model in the two dimensions of arousal and valence (concordance correlation coefficient) were 0.729 and 0.718, respectively, which are superior to several comparative algorithms.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.71-77
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• 2019

Objective: The aim of this study was to investigate postural control strategies on smart phone use during gait in over 50-year-old adults. Method: 8 elderly subjects (age: $55.5{\pm}3.29yrs$, height: $159.75{\pm}4.20cm$, weight: $62.87{\pm}8.44kg$) and 10 young subjects (age: $23.8{\pm}3.19yrs$, height: $158.8{\pm}5.97cm$, weight: $53.6{\pm}5.6kg$) participated in the study. They walked at a comfortable pace in a gaitway of ~8 m while: 1) reading text on a smart phone, 2) typing text on a smart phone, or 3) walking without the use of a phone. Gait parameters and kinematic data were evaluated using a three-dimensional movement analysis system. Results: The participants read or wrote text messages they walked with: slower speed; lesser stride length and step width; greater flexion range of motion of the head; more flexion of the thorax in comparison with normal walking. Conclusion: Texting or reading message on a smart phone while walking may pose an additional risk to pedestrians' safety.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.394-395
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• 2022

Exergames are playing an important role in healthcare/rehabilitation. It has also been used to improve motivation among patients with reduced cognition. The purpose of this pilot study was to evaluate the feasibility of using augmented reality (AR) with game-based cognitive-motor training programs for executive function, restricted and repetitive behaviors (RRBs) in children with autism spectrum disorder. Sixteen children aged 6 -16 years were randomly allocated to the experimental group and control group. Outcome measures were performed before and after the intervention and included executive function, restricted and repetitive behavior. A satisfactory survey was conducted post-intervention. A statistically significant improvement was observed in working memory and cognitive flexibility in the experimental group (P<0.05). However, despite no statistical improvements in cognitive inhibition and four subscales of RRBs, promising changes were observed in all the subscales of the executive function and the behavioral outcomes. Parents appreciated the program and children enjoyed the interaction with the AR game-based training. The findings of this preliminary feasibility study showed that AR using Kinect v2 motion with a cognitive-motor game content can be used for children with autism. However, there is a need for conducting a large-scale study to evaluate his effectiveness on executive function and restricted and repetitive behaviors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.802-810
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• 2012

This paper describes RFID(Radio Frequency Identification) based target acquisition and docking system. RFID is non-contact identification system, which can send relatively large amount of information using RF signal. Robot employing RFID reader can identify neighboring tag attached objects without any other sensing or supporting systems such as vision sensor. However, the current RFID does not provide spatial information of the identified object, the target docking problem remains in order to execute a task in a real environment. For the problem, the direction sensing RFID reader is developed using a dual-directional antenna. The dual-directional antenna is an antenna set, which is composed of perpendicularly positioned two identical directional antennas. By comparing the received signal strength in each antenna, the robot can know the DOA (Direction of Arrival) of transmitted RF signal. In practice, the DOA estimation poses a significant technical challenge, since the RF signal is easily distorted by the surrounded environmental conditions. Therefore, the robot loses its way to the target in an electromagnetically disturbed environment. For the problem, the g-filter based error correction algorithm is developed in this paper. The algorithm reduces the error using the difference of variances between current estimated and the previously filtered directions. The simulation and experiment results clearly demonstrate that the robot equipped with the developed system can successfully dock to a target tag in obstacles-cluttered environment.

• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.855-865
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• 2018

Sound event detection is one of the research areas to model human auditory cognitive characteristics by recognizing events in an environment with multiple acoustic events and determining the onset and offset time for each event. DCASE, a research group on acoustic scene classification and sound event detection, is proceeding challenges to encourage participation of researchers and to activate sound event detection research. However, the size of the dataset provided by the DCASE Challenge is relatively small compared to ImageNet, which is a representative dataset for visual object recognition, and there are not many open sources for the acoustic dataset. In this study, the sound events that can occur in indoor and outdoor are collected on a larger scale and annotated for dataset construction. Furthermore, to improve the performance of the sound event detection task, we developed a dual CNN structured sound event detection system by adding a supplementary neural network to a convolutional neural network to determine the presence of sound events. Finally, we conducted a comparative experiment with both baseline systems of the DCASE 2016 and 2017.

• Korean Journal of Cognitive Science
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• v.20 no.3
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• pp.335-355
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• 2009

We examined risk judgment and the accuracy of inference based on two kinds of probabilities in a Bayesian inference task: the death probability from a disease (base rates) and the probability of having a disease with positive results in the screening test (posterior probabilities). Risk information were presented in either a probability or a frequency format. In Study 1, we found a numerical format effect for both base rate and posterior probability. Participants rated information as riskier and inferred more accurately in the frequency condition than in the probability condition for both base rate and posterior probability. However, there was no frequency range effect, which suggested that the ranges of frequency format did not influence risk ratings. In order to find out how the analytic thought system influences risk ratings, we compared the ratings of a computation condition and those of a no-computation condition and still found the numerical format effect in computation condition. In Study 2, we examined the numerical format effect and frequency range effect in a high and a low probability condition and found the numerical format effect at each probability level. This result suggests that people feel riskier in the frequency format than in the probability format regardless of the base rates and the posterior probability. We also found a frequency range effect only for the low base rate condition. Our results were discussed in terms of the dual process theories.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.475-504
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• 2021

This study is a study that developed class materials that can be applied directly to classes by field teachers in consideration of ' research on the development is valuable as a field support study.', 'In material development, organizing data centering on the knowledge composition and inquiry activities of characters related to the mathematics concept can help develop class materials', and 'The fact that the development of subject data for has been insufficient'. To this end, this study went through the procedure of 'establishing a data development plan, data development, verifying field teachers on development data, verifying subject experts on development data, and developing final data reflecting verification opinions.' Therefore, based on the 1st 50 minutes reflecting the task exploration model, it was possible to develop class materials for the 3rd time. In this study, development data were presented with a 17-week curriculum plan, a class guidance plan that presents teacher-student interaction, and a task development form that students fill out and submit in class. This study was developed with the developed data in mind to be applied to actual classes. Therefore, a follow-up study is needed to apply the developed data to actual classes and analyze the results.