• Communications for Statistical Applications and Methods
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• 제27권6호
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• pp.603-624
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• 2020

There is an emerging interest in brain functional connectivity (FC) based on functional Magnetic Resonance Imaging in Alzheimer's disease (AD) studies. The complex and high-dimensional structure of FC makes it challenging to explore the association between altered connectivity and AD susceptibility. We develop a pipeline to refine FC as proper covariates in a penalized logistic regression model and classify normal and AD susceptible groups. Three different quantification methods are proposed for FC refinement. One of the methods is dimension reduction based on common component analysis (CCA), which is employed to address the limitations of the other methods. We applied the proposed pipeline to the Alzheimer's Disease Neuroimaging Initiative (ADNI) data and deduced pathogenic FC biomarkers associated with AD susceptibility. The refined FC biomarkers were related to brain regions for cognition, stimuli processing, and sensorimotor skills. We also demonstrated that a model using CCA performed better than others in terms of classification performance and goodness-of-fit.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.100-100
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• 2003

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.223-230
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• 2005

This paper presents a new approach to investigate spatial correlation between independent components of brain alpha activity in functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). To avoid potential problems of simultaneous fMRI and EEG acquisitions in imaging pure alpha activity, data from each modality were acquired separately under a 'three conditions' setup where one of the conditions involved closing eyes and relaxing, thus making it conducive to generation of alpha activity. The other two conditions -- eyes open in a lighted room or engaged in a mental arithmetic task, were designed to attenuate alpha activity. Using a Mixture Density Independent Component Analysis (MD-ICA) that incorporates flexible non-linearity functions into the conventional ICA framework, we could identify the spatiotemporal components of fMRI activations and EEG activities associated with the alpha rhythm. Then, the sources of the individual EEG alpha activity component were localized by a Maximum Entropy (ME) method that is specially designed to find the most probable dipole distribution minimizing the localization error in sense of LMSE. The resulting active dipoles were spatially transformed to 3D MRls of the subject and compared to fMRI alpha activity maps. A good spatial correlation was found in the spatial distribution of alpha sources derived independently from fMRI and EEG, suggesting the proposed method can localize the cortical areas responsible for generating alpha activity successfully in either fMRI or EEG. Finally a functional connectivity analysis was applied to show that alpha activity sources of both modalities were also functionally connected to each other, implying that they are involved in performing a common function: 'the generation of alpha rhythms'.

• Annals of Rehabilitation Medicine
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• 제42권6호
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• pp.863-871
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• 2018

Objective To evaluate the association between progression of curvature of scoliosis, and correction for functional component in patients with juvenile idiopathic scoliosis (JIS). Methods We retrospectively reviewed medical data of patients prescribed custom molded foot orthosis (FO) to correct inequality of RCSPA (resting calcaneal stance position angle), and chose 52 patients (26 females, 26 males) with Cobb angle ${\geq}10^{\circ}$ in radiology and uneven pelvic level at iliac crest by different RCSPA (${\geq}3^{\circ}$) as a factor of functional scoliosis. They had different hump angle ${\geq}5^{\circ}$ in forward bending test, for idiopathic scoliosis component. Their mean age and mean period of wearing FO were $79.5{\pm}10.6months$ and $18.6{\pm}0.70months$. Results Cobb angle was reduced from $22.03^{\circ}{\pm}4.39^{\circ}$ initially to $18.86^{\circ}{\pm}7.53^{\circ}$ after wearing FO. Pelvis height difference and RCSPA difference, were reduced from $1.07{\pm}0.25cm$ initially to $0.60{\pm}0.36$, and from $4.25^{\circ}{\pm}0.71^{\circ}$ initially to $1.71^{\circ}{\pm}0.75^{\circ}$ (p<0.01). Cobb angle improved most in 9 months. However, there was no significant improvement for those with more than $25^{\circ}$ of Cobb angle initially. Mean Cobb angle improved in all age groups, but patients less than 6 years had clinically significant improvement of more than $5^{\circ}$. Conclusion JIS can have functional components, which should be identified and managed. Foot orthosis is useful in correcting functional factors, in the case of pelvic inequality caused by different RCSPA, for patients with juvenile idiopathic scoliosis.

• 한국식품조리과학회지
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• 제21권5호
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• pp.742-758
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• 2005

Lipid-based functional components present in foods undergo chemical changes during cooking. Useful n-3 and n-6 fatty acids, phytosterols, tocopherols, and carotenoids are degraded by thermal cooking such as frying, resulting in loss of their physiological functions. However, conjugated linoleic acid and diacylglycerols can be formed during heating, which would be beneficial to the health. Degree of degradation and formation of the functional components depends on the cooking method, cooking temperature and time, lipid matrix containing the components, and the presence of other materials. Although it is clear that the content of each functional component varies during long-heating in a model system consisting of small numbers of components, the real foods cooked in a small scale for a limited cooking time do not show highly significant differences in the functional components contents from raw food materials.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1880-1886
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• 2008

Recently, a railroad system has a big and complicated structure of specification. Therefore, traceability between specification need to be identified for design change management and this is many engineer's concerns. Traceability means technical relationship. This is to trace other specification or component connect with relevant problem in case some problem should be examined. Traceability between functional specification can be proved through functional analysis essentially. This study will introduce an application method of functional analysis in the case of practical use project of MAGLEV train. And we propose the guide to identify traceability between function through functional analysis.

• 한국염색가공학회지
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• 제34권3호
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• pp.146-156
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• 2022

In this study, the dyeing properties of double knit fabric composed of PET/PTT bi-component fiber and quick dry fiber were examined with disperse dyes. In addition, the shrinkage characteristics were investigated during the dyeing process. The K/S values and shrinkage rate of PET/PTT bi-component fiber were higher than those of PET/co-PET bi-component fiber and quick dry fiber. In the dye bath, dye migration of exhausted on PET/PTT bi-component fiber to quick dry fiber was found at high dyeing temperature. It was not found that there was a significant difference in K/S value on dyeing temperature between 115℃ and 130℃. But the slight color difference of two sides of a double knit fabric was found.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권8호
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• pp.980-990
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• 2004

컴포넌트 기반 개발 방법론은 클래스보다 더 큰 단위인 컴포넌트를 통해 높은 추상화와 재사용을 목표로 하는 개발 방법론이다. 컴포넌트 기반 시스템과 개별 컴포넌트의 품질 향상을 위해서는 개발 이전에 측정하고, 그 결과를 컴포넌트 개발 과정에 반영할 수 있어야 한다. 그러므로 컴포넌트 분석 및 설계 단계에 적용 가능한 컴포넌트 메트릭에 대한 연구가 필요하다. 따라서 본 논문에서는 컴포넌트 설계 정보에 기반한 컴포넌트 응집도, 결합도, 독립도 메트릭을 제안한다. 제안한 메트릭은 컴포넌트의 서비스를 제공하기 위한 오퍼레이션들의 동작 유형의 유사도에 기반 한다. 또한, 기능적으로 응집도가 높으며 복잡도가 낮고 유지 보수가 용이한 컴포넌트 설계가 되도록 하기 위한 클러스터링 기법을 사용한 컴포넌트 재설계 과정을 제안한다. 그리고 개발 이전에 컴포넌트 측정과 컴포넌트 재설계 과정을 통해 바람직한 컴포넌트 설계가 되도록 할 수 있음을 사례 연구를 통해 확인했다.

• Annals of Clinical Neurophysiology
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• 제23권2호
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• pp.69-81
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• 2021

Cortico-cortical evoked potential (CCEP) mapping is a rapidly developing method for visualizing the brain network and estimating cortical excitability. The CCEP comprises the early N1 component the occurs at 10-30 ms poststimulation, indicating anatomic connectivity, and the late N2 component that appears at < 200 ms poststimulation, suggesting long-lasting effective connectivity. A later component at 200-1,000 ms poststimulation can also appear as a delayed response in some studied areas. Such delayed responses occur in areas with changed excitability, such as an epileptogenic zone. CCEP mapping has been used to examine the brain connections causally in functional systems such as the language, auditory, and visual systems as well as in anatomic regions including the frontoparietal neocortices and hippocampal limbic areas. Task-based CCEPs can be used to measure behavior. In addition to evaluations of the brain connectome, single-pulse electrical stimulation (SPES) can reflect cortical excitability, and so it could be used to predict a seizure onset zone. CCEP brain mapping and SPES investigations could be applied both extraoperatively and intraoperatively. These underused electrophysiologic tools in basic and clinical neuroscience might be powerful methods for providing insight into measures of brain connectivity and dynamics. Analyses of CCEPs might enable us to identify causal relationships between brain areas during cortical processing, and to develop a new paradigm of effective therapeutic neuromodulation in the future.

• 산업공학
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• 제10권1호
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• pp.155-167
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• 1997

The purpose of this study is to develop the program for efficient operation of a multi-functional surface mounting device(SMD) which mount various components on a printed circuit board(PCB). These components are provided by diverse types of feeders such as cassette, stick and tray feeders. The SMD has one or two heads. In the SMD, the positions of PCB and feeders and fixed, and the head moves to pick up a component from a feeder and to mount it on the PCB. The number of lanes occupied by each feeder and the nozzle used for each component can be different. We develop an off-line program to minimize the cycle-time of the SMD by studying the optimal assignment of feeders and the optimal mounting sequence of components. Graphical User Interface(GUI) is also developed. Additionally, we consider the line balancing problem which appears when two SMDs are used sequentially.