• Journal of Korean Public Health Nursing
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• v.26 no.3
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• pp.404-416
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• 2012

Purpose: The purpose of this study was to explore relationships among cognition, activities of daily living, and depression in persons with decreased memory. Method: Data were collected from 121 out-patients with decreased memory and analysis was performed using descriptive statistics, t-test, ANOVA, Bonferroni test, and Pearson's correlation coefficients with the SPSS/WIN 18.0 program. Result: K-MMSE was significantly increased by BADL (r=.40, p<.001), whereas K-MMSE was significantly decreased by K-IADL (r=-.51, p<.001) and K-IADL significantly decreased by BADL (r=-.51, p<.001). Conclusion: The K-MMSE of persons with decreased memory showed association with BADL and K-IADL. Management of patients complaining of decreased memory and development of nursing interventions will slow down the progression of cognitive impairment.

• Journal of Sasang Constitutional Medicine
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• v.31 no.4
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• pp.57-64
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• 2019

Objectives This study is to investigate the effect of sasang constitutional medicine on the delirium and cognitive decline caused by traumatic subarachnoid hemorrhage in a soeumin alzheimer patient Methods We have treated a 79-year-old Soeumin patient mainly with Doksampalmul-tang. She was already suffering from Alzheimer's disease. After traumatic subarachnoid hemorrhage, there were symptoms of delirium and cognitive decline. The degree of improvement was checked by K-MMSE and K-MOCA scores. Results The K-MMSE score improved from 0 to 11 and the K-MOCA score from 0 to 3. Conclusions Sasang constitutional medicine has been effective in the treatment of delirium and cognitive decline caused by traumatic subarachnoid hemorrhage.

• The Korean Journal of Nuclear Medicine
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• v.36 no.2
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• pp.91-101
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• 2002

Purpose : The aim of this study was to identify the brain areas in which reductions of regional cerebral blood flow (rCBF) were correlated with decline of general mental function, measured by Mini-Mental State Examination (MMSE). Materials and Methods : Tc-99m HMPAO brain SPECT was peformed in 9 probable AD patients at the initial and follow-up periods of 1.8 years (average) after the first study. MMSE scores were also measured in both occasions. The mean MMSE score of the initial study 16.4 (range: 5 - 24) and the mean MMSE score of the follow-up was 8.1 (range: 0 - 17). Each SPECT image was normalized to the cerebellar activity and a correlation analysis was peformed between the level of rCBF in AD patients and the MMSE scores by voxel-based analysis using SPM99 software. Results : Significant correlation was found between the blood-flow decrease in left inferior prefrontal region (BA 47) and left middle temporal legion (BA 21) and the MMSE score changes. Additional areas such as anterior and posterior cingulate cortices, precuneus, and bilateral superior and middle prefrontal regions showed the similar trends. Conclusions : A relationship was found between reduction of regional cerebral blood flow in left prefrontal and temporal areas and decline of cognitive function in Alzheimer's disease(AD) patients. This voxel-based analysis is useful in evaluating the progress of cognitive function in Alzheimer's disease.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1504-1526
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• 2018

For uplink multi-user massive MIMO systems, conventional minimum mean square error (MMSE) linear detection method achieves near-optimal performance when the number of antennas at base station is much larger than that of the single-antenna users. However, MMSE detection involves complicated matrix inversion, thus making it cumbersome to be implemented cost-effectively and rapidly. In this paper, we first summarize in detail the state-of-the-art simplified MMSE detection algorithms that circumvent the complicated matrix inversion and hence reduce the computation complexity from ${\mathcal{O}}(K^3)$ to ${\mathcal{O}}(K^2)$ or ${\mathcal{O}}(NK)$ with some certain performance sacrifice. Meanwhile, we divide the simplified algorithms into two categories, namely the matrix inversion approximation and the classical iterative linear equation solving methods, and make comparisons between them in terms of detection performance and computation complexity. In order to further optimize the detection performance of the existing detection algorithms, we propose more proper solutions to set the initial values and relaxation parameters, and present a new way of reconstructing the exact effective noise variance to accelerate the convergence speed. Analysis and simulation results verify that with the help of proper initial values and parameters, the simplified matrix inversion based detection algorithms can achieve detection performance quite close to that of the ideal matrix inversion based MMSE algorithm with only a small number of series expansions or iterations.

• Analytical Science and Technology
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• v.24 no.6
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• pp.421-428
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• 2011

In this study, headspace disk type monolithic material sorptive extraction (HS-MMSE) was developed, validated and applied to the analysis of volatile aroma compounds from vanilla perfume by gas chromatography -mass spectrometry (GC/MS). HS-MMSE uses monolithic material (MonoTrap) based on silica bonded with octadecyl silane (ODS) and activated carbon as a sorbent. Aroma compounds was adsorbed onto the MonoTrap in headspace and extracted by only 100 ${\mu}L$ of solvent. Total 12 volatile compounds from vanilla perfume were successfully analyzed using HS-MMSE. The influence of extractive parameters was investigated and optimized, using benzyl acetate, linalyl acetate, vanillin, ethyl vanillin as target compounds. Under the optimum condition, the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) of proposed method for the target compounds were obtained within the range of 8.35~13.76 ng and 27.82~45.88 ng, respectively. The method showed good linearity with correlation coefficient more than 0.9888, satisfactory recovery and reproducibility. These results showed that HS-MMSE using disk type MonoTrap is a new promising technique for the analysis of volatile aroma compounds from vanilla perfume.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2120-2133
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• 2013

In this paper, we address the problem of linear minimum mean-squared error (MMSE) transmitter design for the cognitive radio (CR) multi-user multiple-input single-output (MU-MISO) broadcasting channel (BC), where the cognitive users are subject to not only a sum power constraint, but also a interference power constraint. Evidently, this multi-constraint problem renders it difficult to solve. To overcome this difficulty, we firstly transform it into its equivalent formulation with a single constraint. Then by utilizing BC-MAC duality, the problem of BC transmitter design can be solved by focusing on a dual MAC problem, which is easier to deal with due to its convexity property. Finally we propose an efficient two-level iterative algorithm to search the optimal solution. Our simulation results are provided to corroborate the effectiveness of the proposed algorithm and show that this proposed CR MMSE-based scheme achieves a suboptimal sum-rate performance compared to the optimal DPC-based algorithm with less computational complexity.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.117-122
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• 2007

For multiple antenna systems, we consider the hybrid iterative detection of the maximum a posteriori probability(MAP) detection and the linear detection such as the minimum-mean-square-error(MMSE) filtering with soft cancelation. We devise methods to obtain both the lower complexity of the linear detection and the superior performance of the MAP detection. Using the a prior probability of the coded bit which is extrinsic of the outer decoder, we compute the threshold of grouping and determine the detection scheme symbol by symbol. Through the simulation results, it is shown that the proposed receiver obtains the superior performance to the MMSE detector and the lower complexity than the MAP detector.

• Journal of Communications and Networks
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• v.16 no.4
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• pp.447-457
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• 2014

In this paper, we investigate the frequency domain channel estimation for multiple-input multiple-output (MIMO) single-carrier frequency-division multiple-access (SC-FDMA) systems. In MIMO SC-FDMA, code-division multiplexed (CDM) pilots such as cyclic-shifted Zadoff-Chu sequences have been adopted for channel estimation. However, most frequency domain channel estimation schemes were developed based on frequency-division multiplexing of pilots. We first develop a channel estimation error model by using CDM pilots, and then analyze the mean-square error (MSE) of various minimum MSE (MMSE) frequency domain channel estimation techniques. We show that the cascaded one-dimensional robust MMSE (C1D-RMMSE) technique is complexity-efficient, but it suffers from performance degradation due to the channel correlation mismatch when compared to the two-dimensional MMSE (2D-MMSE) technique. To improve the performance of C1D-RMMSE, we design a robust iterative channel estimation (RITCE) with a frequency replacement (FR) algorithm. After deriving the MSE of iterative channel estimation, we optimize the FR algorithm in terms of the MSE. Then, a low-complexity adaptation method is proposed for practical MIMO SC-FDMA systems, wherein FR is performed according to the reliability of the data estimates. Simulation results show that the proposed RITCE technique effectively improves the performance of C1D-RMMSE, thus providing a better performance-complexity tradeoff than 2D-MMSE.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.279-286
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• 2016

Recently, with the population growth of elderly people, concerns about oral health related to the quality of life of the elderly are increasing. The purpose of this study is to assess the association between the elderly women divided into dementia, suspected dementia, healthy groups and the remaining teeth of them. Total 177 elderly women of over 60 years old, visiting on senior center in some community dwelling, were assessed for oral condition and their cognitive function with MMSE score. All the collected data were analyzed by chi-square test, t-test, and multiful logistic regression using SPSS. Multiful logistic regression was used to analyze the relationship of dementia according to MMSE score and remaining teeth, and 95% confidence intervals were computed. Odds ratio(OR) of the number of remaining teeth 0-10 was 3.43 (95% confidence interval: 1.382-8.997). This study showed significant difference and the relationship between dementia according to MMSE score and the number of remaining teeth of the elderly women.

• Journal of the Korea Society of Computer and Information
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• v.22 no.5
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• pp.51-56
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• 2017

The purpose of this study was to identify differences in cognitive function according to the presence or absence of apraxia and the tasks most relevant to the cognitive function among the various types of tasks in the apraxia test. The subjects were 42 community residents who participated in a cognitive rehabilitation program related to dementia in a Chungbuk area. MMSE-K and BCoS(Birmingham Cognitive Screen) apraxia test were administered to all subjects. The apraxia test includes three types of tasks, gesture production tasks that make meaningful movements according to verbal instructions, gesture recognition tasks that display behavior after make sense of meanings, and meaningless imitation task. Apraxia group(n=30, MMSE-K mean score: 25) showed lower cognitive function than group without apraxia(n=12, MMSE-K mean score: 28). All tasks in the apraxia test showed a significant correlation with cognitive function, but the meaningless imitation task had a negligible correlation. The apraxia test is a good way to assess cognitive function, and it may be more effective to use meaningful behavior to replace cognitive testing.