• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.31-36
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• 2012

In this paper, we proposed spectrum sensing using cooperative relay to solve problem of sensing performance degradation due to CPE (Customer-Premises equipments) which causes low SNR (signal-to-noise ratio) problem. In cooperative communication system, AF (amplify-and-forward) and DF (decoded-and-forward) is widely used for relay mechanism. Also, it is expected that cooperative relay scheme guarantees the high sensing performance by its diversity gain. Based on these backgrounds, in this paper, we apply to cooperative relay scheme to the CR (Cognitive Radio) system, and simulation results show comparison of the sensing performance.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 한국인지과학회 2000년도 한글 및 한국어 정보처리
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• pp.323-328
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• 2000

국내에서 영한 자동번역 시스템을 1985 년부터 개발한 지 벌써 15년이 흐르고 있다. 15년의 영한 자동번역 기술개발에도 불구하고 아직도 영한 자동번역 시스템의 번역품질은 40%를 넘지 못하고 있다. 이렇게 번역품질이 낮은 이유는 다음과 같이 요약할 수 있을 것이다. $\textbullet$ 입력문에 대해 파싱할 때 오른쪽 경계를 잘못 인식함으로써 구조적 모호성의 발생문제: 예를 들어 등위 접속절에서 오른쪽 등위절이 등위 접속절에 포함되는 지의 모호성. $\textbullet$ 번역 단위로써 전체 문장을 대상으로 한 번역패턴이 아닌 구나 절과 같은 부분적인 번역패턴으로 인한 문장 전체의 번역 결과 발생. $\textbullet$ 점차 증가하는 대용량 번역지식의 구축과 관련해 새로 구축되는 번역 지식과 기구축된 대용량 번역지식들 간의 상호 충돌로 인한 번역 품질의 저하. 이러한 심각한 원인들을 극복하기 위해 본 논문에서는 문틀에 기반한 새로운 영한 자동번역 방법론을 소개하고자 한다. 이 문틀에 기반한 영한 자동번역 방법론은 현재 CNN 뉴스 방송 자막을 대상으로 한 영한 자동번역 시스템에서 실제 활용되고 있다. 이 방법론은 기본적으로 data-driven 방법론에 속한다. 문틀기반 자동번역 방법론은 규칙기반 자동번역 방법론보다는 낮은 단계에서 예제 기반 자동번역 방법론 보다는 높은 단계에서 번역을 하는 번역방법론이다. 이 방법론은 영한 자동번역에 뿐만 아니라 다른 언어쌍의 번역에서도 적용할 수 있을 것이다.

• Korean Journal of Biological Psychiatry
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• 제21권4호
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• pp.175-181
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• 2014

Objectives It was the aim to examine the association of the thyroid-related hormones with cognitive function, depression, and subjective memory impairment in community-dwelling elders with questionable dementia. Methods The sample consisted of 399 community residents with 'questionable dementia' aged 60 or over in whom serum thyroid-related hormones [thyroid stimulating hormone (TSH) and thyroxine] had been assayed. Cognitive impairment was defined using the Korean version of the Consortium Establish a Registry for Alzheimer's Disease. Depression was diagnosed using the Korean version of Geriatric Depression Scale and subjective memory complaint (SMC) was checked using the subjective memory complaints questionnaire (SMCQ). Age, gender, education, and the presence of apolipoprotein E {\varepsilon}4 were included as covariates. Results There was a significant positive association between verbal fluency test (VFT) score and serum TSH levels (p = 0.01). There was a significant negative association between SMCQ total score and word list memory test (WLMT)(p = 0.002) or word list recall test (WLRT) score (p = 0.013). Conclusions Lower serum TSH levels were associated with semantic memory (VFT), and we found that SMC was associated with episodic memory (WLMT and WLRT) in this sample.

• Journal of Satellite, Information and Communications
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• 제7권1호
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• pp.7-12
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• 2012

In this paper, we proposed spectrum sensing using cooperative relay to solve problem of sensing performance degradation due to CPE (Customer-Primise equipments) which causes low SNR (signal-to-noise ratio) problem. In cooperative communication system, AF (amplify-and-forward) and DF (decoded-and-forward) is widely used for relay mechanism. Also, it is expected that cooperative relay scheme guarantees the high sensing performance by its diversity gain. Based on these backgrounds, in this paper, we apply to cooperative relay scheme to the CR (cognitive radio) system, and simulation results show comparison of the sensing performance between AF and DF.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제11권7호
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• pp.1254-1259
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• 2007

Watermark insertion methods on low frequency subbands in wavelet transform image are robust in attacks, but become reduction of invisibility. And watermark insertion methods on high frequency subbands have a good visibility, but are weak in attack. In this paper, we propose the method that improve invisibility and robustness of watermarks according as we adaptively control insertion intensity by using subband characteristics and perceptual weights. Experimental result, we show that the proposed method has excellent of invisibility and robustness more than the conventional method, according as it is improved with $1.7dB{\sim}2.6dB$ in invisibility, and is improved with $0.2{\sim}12.9$ in similarity measurement.

• Journal of East-West Nursing Research
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• 제30권1호
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• pp.31-41
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• 2024

Purpose: This study aimed to identify factors affecting subjective cognitive decline (SCD) in men and women. Methods: This study was conducted based on data from the 2021 Korea Community Health Survey, and targeted a total of 80,026 men and 98,753 women aged 40 or older who responded to the SCD assessment. Multivariate logistic regression analysis using a complex sample was performed to identify factors influencing SCD. Results: Of the participants, 19,438 (22.7%) men and 30,826 (29.9%) women in the community reported SCD. Significant factors that influence SCD in both groups were age, education level, subjective health status, and depressive symptoms, and the strongest risk factor was depressive symptoms. Compared to women, men's monthly income, flexibility exercise, hypertension, and diabetes mellitus were found to be significant factors on SCD and Healthcare services affected SCD only in women. Medical services affected SCD only in women. Conclusions: When planning and providing intervention programs for cognitive function, it is necessary to reflect differences in factors associated with SCD according to sex.

• The Journal of the Convergence on Culture Technology
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• 제5권4호
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• pp.349-354
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• 2019

Workers who die from falls at construction sites account for about 40 percent of the total number of deaths and are the main forms of accidents. In addition, as the nation's population structure is gradually aging, the rate of aging is increasing at construction sites, and the number of crashes due to decreased physical function and cognitive ability is increasing. Accordingly, we conducted a survey on the factors affecting the fall of older workers and would like to present more fundamental measures to prevent falls, focusing on older workers who are the victims of the disaster.

• Journal of Digital Convergence
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• 제19권12호
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• pp.353-358
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• 2021

Parkinson's disease is the second most common degenerative brain disease after Alzheimer's in old age. Symptoms of Parkinson's disease are factors that reduce the quality of life in daily life, such as shaking hands, slowing behavior and cognitive function. Parkinson's disease that can slow the progression of the disease through early diagnosis. To diagnoze Parkinson's disease early, an algorithm was implemented to extract features using wav2vec and to diagnose the presence or absence of Parkinson's disease with deep learning(ANN). As a results of the experiment, the accuracy was 97.47%. It was better than the results of diagnosing Parkinson's disease using the existing neural network. The audio voice file could simply reduce the experiment process and obtain improved results.

• Sleep Medicine and Psychophysiology
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• 제1권2호
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• pp.163-171
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• 1994

Objectives: Symptoms of sleep apnea consisted of insomnia, excessive sleepiness during daytime, impaired cognitive functions and emotional disturbances. It was not so well known how these symptoms are correlated with various parameters of sleep and respiration, and what kind of psychophysiological processes are involved in development of these symptoms. Methods: In sixty patients with sleep apnea, sleep and respiration were studied by polysomnography of one night, also symptoms of sleep apnea were evaluated with the scales of insomnia, daytime sleepiness, emotional disturbance and cognitive impairment We studied correlations between apnea symptoms, and various parameters of sleep and respiration such as sleep efficiency, number severity of apnea, $O_2$ desaturation and number of snoring. Results: The result showing significant correlations are as follows. The patients with better sleep in insomnia scale showed more number of apnea, particularly more central type, and much more snoring in stage 3 sleep and mild desaturation of $O_2$. Excessive sleepiness during daytime correlated significantly with stage 1 sleep and its snoring, but correlated negatively with stage 2 sleep. However, no significant correlation was found with degree of $O_2$ desaturation. Emotional disturbance was more apparent in the patients with severe $O_2$ desaturation and smaller amounts of stage 4 sleep. Cognitive function was more impaired in cases of more REM sleep and less apnea. Conclusions: Symptoms of sleep apnea may occur through different causes and processes. The evaluation of apnea symptoms may be helpful to understand in some degree the condition of sleep and respiration during sleep in clinical setting.

• Korean Journal of Cognitive Science
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• 제25권2호
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• pp.159-187
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• 2014

Approximate number sense(hereafter, ANS) is the ability to compare and operate upon numerosity information. The numerosity comparison task is used to measure ANS. However, there is considerable variance among previous reports of ANS acuity which may be related to different task formats used. Here, we aim to investigate whether the format of the numerosity comparison task influences measurements of ANS acuity. We compared two task formats; 1) an intermixed format presenting two intermixed arrays of black and white dots, and 2) a side-by-side format showing two arrays of dots side by side. The intermixed format likely makes additional demands on general cognitive resources for inhibitory control, selective attention, or visuospatial working memory. The performance on the intermixed format was significantly lower than that of the side-by-side format resulting in an underestimation of ANS acuity compared to the expected trajectory of ANS development. In addition, the ANS acuity measured from only the side-by-side format was correlated with children's mathematical achievement and age. Our results demonstrate that measurement of ANS from the side-by-side format has higher construct and predictive validity compared to that of the intermixed format.