• 전기학회논문지
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• 제65권1호
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• pp.122-127
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• 2016

In this paper, new spectrum sensing schemes based on analog/RF front-end processing are introduced for IoT wireless sensor networks. While the conventional approaches for wireless channel cognition have been issued in signal processing area, the RF spectrum cognition concept makes it feasible to achieve cognitive wireless sensor networks (C-WSNs). The spectrum cognition at RF processing is categorized as four kinds of sensing mechanisms. Two recent reseaches are described as promising candidates for the C-WSN. One senses spectrum by the frequency discriminating receiver, the other senses and detects from the frequency selective super-regenerative receiver. The introduced systems with simple and low-power RF architectures play dual roles of channel sensing and demodulation. simultaneously. Therefore, introduced spectrum sensing receivers can be one of the best candidates for IoT wireless sensor devices in C-WSN environments.

• Psychiatry investigation
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• 제15권12호
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• pp.1144-1153
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• 2018

Objective One of the areas of social cognition is Theory of Mind (ToM) is defined as the capacity to interpret, infer and explain mental states underlying the behavior of others. When social cognition studies on neurodevelopmental disorders are examined, it can be seen that this skill has not been studied sufficiently in children with Specific Learning Disorder (SLD). Methods In this study, social cognition skills in children diagnosed with attention deficit hyperactivity disorder (ADHD), SLD or Autism Spectrum Disorder (ASD) evaluated before puberty and compared with controls. To evaluate the ToM skills, the first and second-order false belief tasks, the Hinting Task, the Faux Pas Test and the Reading the Mind in the Eyes Task were used. Results We found that children with neurodevelopmental disorders as ADHD, ASD, and SLD had ToM deficits independent of intelligence and language development. There was a significant correlation between social cognition deficits and problems experienced in many areas such as social communication and interaction, attention, behavior, and learning. Conclusion Social cognition is an important area of impairment in SLD and there is a strong relationship between clinical symptoms and impaired functionality.

• 한국위성정보통신학회논문지
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• 제7권3호
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• pp.1-7
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• 2012

본 논문은 TV 화이트 스페이스(TV white space) 대역에서 1차 우선 사용자인 DVB-T2(Digital Video Broadcasting - Second Generation Terrestrial) 차세대 유럽형 방송 서비스와 스펙트럼 인지 기능이 탑재된 IMT-Advanced LTE 기반 개인/휴대용 TVBD(TV Band Device) 무선기기와의 공존 가능성 파악을 위해 간섭분석을 수행하였다. 이를 위해 실제 유럽에서 적용되는 DVB-T2와 TVBD 각각에 대해 방사 및 블로킹 마스크, 안테나 높이 및 이득, 전송전력 및 대역폭, 송수신 링크에 대한 채널모델을 적용하였다. 이를 기반으로 DVB-T2의 인접채널에서 동작 가능한 TVBD 사용자의 허용가능 전송전력과 개수, 간섭환률 변화량에 대한 분석을 수행하였다. 또한 스펙트럼 인지 성능에 따른 허용가능 TVBD 총 개수의 변화량에 대해서도 분석을 수행하였다.

• 한국통신학회논문지
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• 제31권7C호
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• pp.672-679
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• 2006

Cognitive radio, which is designed to dynamically adapt its transmission to the environments, is believed to be one of the fundamental techniques for future spectrum utilization. As the first step of cognitive radio, spectrum sensing is treated as the most important technique, through which cognition is well explained. In this paper, we propose a spectral correlation based detection method for spectrum sensing. An unlicensed secondary user system operating in TV broadcast bands is taken as an example. Based on the cyclostationarity of communication signals, spectral correlation function is used to minimize the effect of random noise and interference. Energy measurement and peak detection based criteria are proposed. Simulation results show that the proposed detection method outperforms the energy detection and is more suitable for spectrum sensing in cognitive radios.

• Journal of information and communication convergence engineering
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• 제17권1호
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• pp.21-40
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• 2019

This paper presents a comprehensive survey of various artificial intelligence (AI) techniques implemented in cognitive radio engine to improve cognition capability in cognitive radio networks (CRNs). AI enables systems to solve problems by emulating human biological processes such as learning, reasoning, decision making, self-adaptation, self-organization, and self-stability. The use of AI techniques is studied in applications related to the major tasks of cognitive radio including spectrum sensing, spectrum sharing, spectrum mobility, and decision making regarding dynamic spectrum access, resource allocation, parameter adaptation, and optimization problem. The aim is to provide a single source as a survey paper to help researchers better understand the various implementations of AI approaches to different cognitive radio designs, as well as to refer interested readers to the recent AI research works done in CRNs.

• 재활간호학회지
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• 제9권1호
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• pp.72-80
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• 2006

Purpose: This study was conducted to examine the effect of multidimensional program on cognition, physical function and depression among institutionalized elderly and the relationship between study variables and resident's characteristics and health related variables. Method: This study involved a one group pre and post test, comparison of variables over a 12 month period. To investigate this research question, data of 114 residents of a nursing home were analyzed. Results: There was statistically significant difference in MMSE-K (t=-2.63, p=.010), ADL (t=-2.85, p=.005), and depression (t=4.66, p=.000) before and after program participation. Conclusion: These results indicate that, for a year their regular involvement in a broad spectrum of multidimensional program activities can improve in cognitive, physical and emotional perspectives, but the level of IADL decreased significantly (t=-6.72, p=.000). Further testing is required with the control group, to compare with community resident elders in order to explore the effects on social skill of elderly.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제31권3호
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• pp.105-120
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• 2020

Although autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social impairments, patients with ASD frequently manifest atypical sensory behaviors. Recently, atypical sensory perception in ASD has received much attention, yet little is known about its cause or neurobiology. Herein, we review the findings from neuroimaging studies related to visual perception in ASD. Specifically, we examined the neural underpinnings of visual detection, motion perception, and face processing in ASD. Results from neuroimaging studies indicate that atypical visual perception in ASD may be influenced by attention or higher order cognitive mechanisms, and atypical face perception may be affected by disrupted social brain network. However, there is considerable evidence for atypical early visual processing in ASD. It is likely that visual perceptual abnormalities are independent of deficits of social functions or cognition. Importantly, atypical visual perception in ASD may enhance difficulties in dealing with complex and subtle social stimuli, or improve outstanding abilities in certain fields in individuals with Savant syndrome. Thus, future research is required to elucidate the characteristics and neurobiology of autistic visual perception to effectively apply these findings in the interventions of ASD.

• 대한조현병학회지
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• 제21권2호
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• pp.74-80
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• 2018

Objectives : This study investigated whether long-acting injectable (LAI) paliperidone is different from its oral form in terms of the effect on cognitive function in schizophrenia spectrum and other psychotic disorders. Methods : We reviewed the medical records of patients in Seoul National University Bundang Hospital who were diagnosed as having schizophrenia and/or other psychotic disorders based on DSM-5 from 2016 to 2017. Seven patients were treated with oral paliperidone and 11 were treated with paliperidone palmitate. All patients underwent clinical and neuropsychological assessment, including the Korean version of the MATRICS Consensus Cognitive Battery (MCCB) at their first visit or within one month of their initial treatment. MCCB was repeated within three to 12 months after the initial assessment. Results : There was no significant difference between the two groups in most cognitive domains including speed of processing, attention and vigilance, working memory, verbal learning, visual learning and reasoning and problem solving domain. However, patients treated with paliperidone palmitate showed better improvement in social cognition domain than those taking oral paliperidone. The standardized values of social cognition domain scores had significantly improved over time in patients under paliperidone palmitate, demonstrating a significant time-by-group interaction. Conclusion : Our results show that long-acting injectable paliperidone could be helpful in some aspects of improving cognitive function in schizophrenia spectrum and other psychotic disorders. Further studies with other antipsychotics are necessary to generalize the results.

• Korean Journal of Radiology
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• 제24권11호
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• pp.1131-1141
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• 2023

Objective: Cortical iron deposition has recently been shown to occur in Alzheimer's disease (AD). In this study, we aimed to evaluate how cortical gray matter iron, measured using quantitative susceptibility mapping (QSM), differs in the clinical cognitive impairment spectrum. Materials and Methods: This retrospective study evaluated 73 participants (mean age ± standard deviation, 66.7 ± 7.6 years; 52 females and 21 males) with normal cognition (NC), 158 patients with mild cognitive impairment (MCI), and 48 patients with AD dementia. The participants underwent brain magnetic resonance imaging using a three-dimensional multi-dynamic multi-echo sequence on a 3-T scanner. We employed a deep neural network (QSMnet+) and used automatic segmentation software based on FreeSurfer v6.0 to extract anatomical labels and volumes of interest in the cortex. We used analysis of covariance to investigate the differences in susceptibility among the clinical diagnostic groups in each brain region. Multivariable linear regression analysis was performed to study the association between susceptibility values and cognitive scores including the Mini-Mental State Examination (MMSE). Results: Among the three groups, the frontal (P < 0.001), temporal (P = 0.004), parietal (P = 0.001), occipital (P < 0.001), and cingulate cortices (P < 0.001) showed a higher mean susceptibility in patients with MCI and AD than in NC subjects. In the combined MCI and AD group, the mean susceptibility in the cingulate cortex (β = -216.21, P = 0.019) and insular cortex (β = -276.65, P = 0.001) were significant independent predictors of MMSE scores after correcting for age, sex, education, regional volume, and APOE4 carrier status. Conclusion: Iron deposition in the cortex, as measured by QSMnet+, was higher in patients with AD and MCI than in NC participants. Iron deposition in the cingulate and insular cortices may be an early imaging marker of cognitive impairment related neurodegeneration.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.125-127
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• 2004

High-resolution satellite images offer abundance information of the earth surface for remote sensing applications. The information includes geometry, texture and attribute characteristic. The pixel-based image classification can't satisfy high-resolution satellite image's classification precision and produce large data redundancy. Object-oriented information extraction not only depends on spectrum character, but also use geometry and structure information. It can provide an accessible and truly revolutionary approach. Using Beijing Spot 5 high-resolution image and object-oriented classification with the eCognition software, we accomplish the cultures' precise classification. The test areas have five culture types including water, vegetation, road, building and bare lands. We use nearest neighbor classification and appraise the overall classification accuracy. The average of five species reaches 0.90. All of maximum is 1. The standard deviation is less than 0.11. The overall accuracy can reach $95.47\%.$ This method offers a new technology for high-resolution satellite images' available applications in remote sensing culture classification.