• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.173-178
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• 1999

Purpose : To evaluate the usefulness of functional MRI (fMRI) of visual cortex in patients with ischemic infarction in the occipital lobe. Materials and Methods : Four patients with the symptoms and signs of visual cortical ischemia were included. Functional MRI was performed by 2D-FLASH technique with the parameter of 90/56msec TR/TE, $40^{\circ}$ flip angle, $240{\times}240{\;}FOV,{\;}64{\times}128$ matrix number, 8.32 seconds acquisition time, 8mm slice thickness. An axial slice including both visual cortices was selected and alternative activation and resting of the visual cortex was performed using red color photostimulator. all patients undertook visual field test, and vascular abnormality was examined by MRA (n=4) and DSA (n=2). fMRI results were compared with the results of a visual field test, conventional MRI and cerebral angiography. Results : On fMRI, decreased activity of the visual cortex was found in the occipital lobe corresponding to stenosis of the posterior cerebral artery or its branch noted on angiogram. However, 2 of 4 patients showed no abnormal findings on conventional MRI. Visual field defect was noted in 3 patients, one and of whom showed no abnormality on conventional MRI and diffusion-weighted image, but revealed decreased activity in the corresponding visual cortex on fMRI. Conclusion : fMRI may be a sensitive method for detection of the status of decreased blood flow or vascular reserve which other methods can not.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.898-901
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• 2010

본 연구는 만성 뇌졸중 환자를 대상으로 시각리듬자극(RVS)을 이용한 보행 운동을 적용하여 보행과 고유수용성감각에 미치는 효과를 알아보고자 하였다. 뇌졸중으로 6개월 이상 장애를 가진 21명이 연구에 참여하였고 실험군 10명과 대조군 11명으로 나누었다. 대조군은 14m의 보행로가 확보된 공간에서 준비운도 5분, 보행운동 20분, 정리운동 5분 씩 주 3회, 4주간 12회을 실시하였고, 실험군은 대조군의 운동프로그램과 같은 조건에서 보행운동시 시각리듬자극(RVS)을 추가적으로 적용하였다. 운동 전과 후에 보행과 고유수용성감각을 측정하여 효과를 비교하였다. 통계처리 방법으로 실험 전 후 차이를 검증하기 위하여 대응표본 t 검정을 실시하였고 대조군과의 차이 검증을 위하여 독립표본 t 검정을 실시하였다. 모든 통계적 유의수준은 0.05로 하였다. 본 연구의 결과 시각리듬자극(RVS)이 적용된 실험군에서 보행속도와 분속수, TUG 시간이 유의하게 증가하였고(p<.05), 고유수용성감각이 유의하게 증가하였다(p<.05). 결론적으로 시각리듬자극(RVS)을 이용한 보행운동이 만성 뇌졸중 환자의 보행과 고유수용성감각에 효과가 있는 것으로 나타났다. 향후 만성 뇌졸중 환자에게 음악적 요소인 시각리듬자극 (RVS)이 정신적 육체적 기능을 상실한 뇌졸중 환자의 재활치료 프로그램에 적용하는 연구가 필요할 것으로 기대되어진다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.210-213
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• 2011

기억 인출 단서는 학습을 통해 장기기억 공간에 저장된 정보를 인출하는 과정에서 중요하며, 서로 다른 종류의 기억 인출 단서에 따른 기억 인출 결과 및 이에 대한 인지 학습적 특성 규명은 교육, 범죄 수사, 그리고 인간의 뇌 기능을 모방한 기계학습 연구 등에서 중요하게 다루어져야 할 문제이다. 본 논문에서는 비디오 데이터를 이용하여 학습한 내용을 인출하는 과정에서 텍스트와 이미지가 각각 인출 단서로서 기억인출 결과에 미치는 영향을 분석하고, 기억 정보 및 시각 정보 처리와 관련된 뇌 영역에서의 뇌전도 분석을 이용하여 이를 해석하였다. 실험 결과를 통해 기억 인출을 위해 이미지-텍스트를 제시할 경우 전전두엽의 기억인출 관련 부위와 시각 피질이 위치한 후두엽의 인터랙션이 높게 이루어지면서 암묵적인 시각적기억 표상의 인출이 발생하는 것을 알 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.74-75
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• 2013

Pseudolite is a contraction of the term "pseudo-satellite," used to refer to something that is not a satellite which performs a function commonly in the domain of satellites. Pseudolite are most often small transceivers that are used to create a local, ground-based GPS alternative. This paper proposes a clock synchronization scheme for pseudolite.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.978-979
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• 2023

시각 장애인들은 식품의 영양 정보 표시 부재로 인해 식품 섭취에 어려움을 겪고 있는 상황이며, 전국 등록 장애인 수는 고령화와 함께 지속적으로 증가하는 추세이다. 이에 따른 돌봄 인력 부족 및 돌봄 예산 증가가 예상되고 있다. 이러한 배경을 고려하여, 본 논문에서는 시각 장애인들에게 영양을 고려한 식자재를 제공하기 위한 과채류 수확 로봇을 개발하고 제공함으로써, 과채류 섭취 부족 문제와 돌봄 인력 부족 문제를 해결하는 것을 목표로 한다. 특히, 본 제품은 사용자의 편의성을 고려하여 음성 인식 기능을 도입하고, 사용자의 요구사항에 따른 권장 섭취량을 기반으로 수확 및 자율주행 배달 서비스를 제공한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5485-5491
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• 2015

The purpose of this study is to investigate PR-VEP characteristics on the perception function(S/N) and the judgement function(T/F) of MBTI. The 136 study participants, over 20 years old adults, were examined by PR-VEP and MBTI test for two months in July and August in 2013. PR-VEP was conducted in O1 and O2 by 32 channels EEG system and MBTI test was measured by Form-M online. We found that the time interval(Duration) between N75 and P100 of PR-VEP was 5.49 ms significantly shorter in the group preferring S indicator. And the latency until N75 was 4.83 ms significantly shorter in O1 and 4.27 ms shorter in O2 in the group preferring F indicator. According to these, the characteristics of groups preferring S and F indicator have influence on visual cognitive function, which is meaningful that the interpretation of brain-science can be used with recognition/judgement function of MBTI.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.5
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• pp.104-108
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• 2004

The most of the CDMA mobile communication depends on the GPS for the time synchronization. Then, we must prepare alternative system against the unusable GPS like a unexpectable accident or strategic purpose by the USA government. In this study, we have constructed ground test segment for the time synchronization system using the geostationary satellite. In addition. we have designed, manufactured and tested the transmitting and receiving board to receive 1 PPS signal from atomic clock for transmitting stored data in buffer to satellite modem and to produce 1 PPS signal from satellite modem for measuring time delay.

• Journal of Platform Technology
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• v.8 no.4
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• pp.20-28
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• 2020

In this paper, a voice, object, and optical character recognition platform including voice recognition-based smart wearable devices, smart devices, and web AI servers was proposed as an appropriate technology to help the visually impaired to live independently by learning the life cycle of the visually impaired in advance. The wearable device for the visually impaired was designed and manufactured with a reverse neckband structure to increase the convenience of wearing and the efficiency of object recognition. And the high-sensitivity small microphone and speaker attached to the wearable device was configured to support the voice recognition interface function consisting of the app of the smart device linked to the wearable device. From experimental results, the voice, object, and optical character recognition service used open source and Google APIs in the web AI server, and it was confirmed that the accuracy of voice, object and optical character recognition of the service platform achieved an average of 90% or more.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.337-344
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• 2013

This research has been conducted to determine the effect that the visually handicapped's participation in an aerobic exercise program has on cardiorespiratory function and arterial pulse wave. The subjects of this research were 20 people who have a 1st degree visual impairment. They recognized the purpose of this research and agreed to take part in it. After receiving agreements from their guardians, we divided them into an exercise group of 10 and a comparison group of 10 at random. The exercise group conducted a 50-70%HRmax treadmill exercise for 60 minutes a day, five times a week, for 12 weeks, including warm up and warm down exercises. We then conducted a two-way repeated ANOVA, which regards the period of exercise and the two groups as independent variables. The follow-up verification for exercise periods according to each group was carried out with a paired t-test. The statistical significance level was p<.05. The following are the results of this research. First, the weight and body fat of the experiment group after exercise show a meaningful reduction compared to before the exercise program (p<.05).Second, the VO2max, HRmax, and VEmax of the experiment group after exercise show a meaningful increase compared to before the exercise program (p<.05). Third, the arterial pulse wave of the experiment group after exercise display a meaningful increase compared to before the exercise program (p<.05). Fourth, the systolic blood pressure of the experiment group after exercise does not show a meaningful reduction compared to before the exercise program (p>.05). These results prove that the visually handicapped's participation in an aerobic exercise program is effective in the improvement of their cardiorespiratory function, bloodstream circulation function and blood vessel function.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1312-1317
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• 2013

Pseudolite is a contraction of the term "pseudo-satellite", used to refer to something that is not a satellite which performs a function commonly in the domain of satellites. Pseudolite are most often small transceivers that are used to create a local, ground-based GPS alternative. Pseudo-range measurement of pseudolite has around 300m range error, when time synchronization error of $1{\mu}sec$ occurs. Therefore the time synchronization methods play an important part in navigation augmentation using pseudolite. This paper proposes three clock synchronization methods that are installation method of pseudolite station, method using KRISS-UTC and method using PRN code phase difference for pseudolite. The simulation platform structure is presented for evaluating proposed clock synchronization performance.