• Current Optics and Photonics
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• 제5권4호
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• pp.431-443
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• 2021

Sparse unmixing has been proven to be an effective method for hyperspectral unmixing. Hyperspectral images contain rich spectral and spatial information. The means to make full use of spectral information, spatial information, and enhanced sparsity constraints are the main research directions to improve the accuracy of sparse unmixing. However, many algorithms only focus on one or two of these factors, because it is difficult to construct an unmixing model that considers all three factors. To address this issue, a novel algorithm called multiview-based spectral weighted and low-rank row-sparsity unmixing is proposed. A multiview data set is generated through spectral partitioning, and then spectral weighting is imposed on it to exploit the abundant spectral information. The row-sparsity approach, which controls the sparsity by the l_2,0 norm, outperforms the single-sparsity approach in many scenarios. Many algorithms use convex relaxation methods to solve the l_2,0 norm to avoid the NP-hard problem, but this will reduce sparsity and unmixing accuracy. In this paper, a row-hard-threshold function is introduced to solve the l_2,0 norm directly, which guarantees the sparsity of the results. The high spatial correlation of hyperspectral images is associated with low column rank; therefore, the low-rank constraint is adopted to utilize spatial information. Experiments with simulated and real data prove that the proposed algorithm can obtain better unmixing results.

• Journal of the Chungcheong Mathematical Society
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• 제15권1호
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• pp.25-33
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• 2002

We prove the generalized Hyers-Ulam-Rassias stability of linear operators in a Hilbert module over a unital $C^*$-algebra.

• Bulletin of the Korean Mathematical Society
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• 제54권5호
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• pp.1859-1871
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• 2017

We compute the Jordan constant for the group of birational automorphisms of a projective plane ${\mathbb{P}}^2_{\mathbb{k}}$, where ${\mathbb{k}}$ is either an algebraically closed field of characteristic 0, or the field of real numbers, or the field of rational numbers.

• Progress in Medical Physics
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• 제20권4호
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• pp.208-215
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• 2009

This study is to compare the accuracy of evaluation regarding the volume of the prostate, which three-dimensional volume rendering was produced the shape of protrusion, by measuring two kinds of craniocaudal length from the top of the protrusion and from the exclusion of the protrusion as the starting points. For the imaginary protrusion prostate models, total of 10 models were roughly made by using devils-tongue jelly and changing each of the 10 ml of capacity from 10 ml to 100 ml. For the protrusion prostate models aimed at estimating the real volume, through 64 cannel computed tomography (CT) and 3.0 tesla magnetic resonance image (MRI) were conducted by planimetry technique from three-dimensional volume rendering. And then we performed to evaluate on significance of these volumes by wilcoxon signed rank test. Also the obtained volumes data by ellipsoid volume formula were measured the volume of protrusion prostate models two times with each method using the two kinds of craniocaudal length from top of the protrusion and from exclusion of the protrusion as the starting points. Finally, the significance of differences using wilcoxon signed rank test was evaluated between the real volume by planimetry technique and the measured volume by ellipsoid volume formula from three-dimensional volume rendering. The average of the protrusion length on the models was $0.90{\pm}0.18\;mm$ in CT and was $0.75{\pm}0.11\;mm$ in MRI. There were not statistically significant difference between MRI and CT from the volume of protrusion prostate models (p=0.414). In MRI (p=0.139) and CT (p=0.057), there were not statistically significant difference between the real volume by planimetry technique and the measured volume by ellipsoid volume from exclusion of the protrusion as the starting points. While, there were statistically significant difference between the real volume by planimetry technique and the measured volume by ellipsoid volume from top of the protrusion as the starting points in MRI (p=0.005) and CT (p=0.005). For the accurate measurement of the protrusion prostate models, the craniocaudal length of the prostate should be measured from the exclusion of the protrusion as the starting points.

• Proceedings of the Acoustical Society of Korea Conference
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• 한국음향학회 2002년도 하계학술발표대회 논문집 제21권 1호
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• pp.107-110
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• 2002

현재까지 개발된 화자식별 시스템 중 가중모델순위(Weighting Model Rank; WMR)방법을 이용한 화자인식 시스템이 비교적 높은 인식성능을 나타내고 있다. WMR 방법은 각 화자에 대한 프레임 유사도의 순위에 따라 지수함수 가중치로 대치시키는 방법을 사용하고 있으나, 이 방법은 유사도 본래의 변별력이 전체 계산에서 고려되지 않는 문제가 있었다. 이를 해결하기 위해 본 논문에서는 각 화자의 프레임 유사도와 지수함수를 이용한 가중치를 곱한 값을 이용하여 전체 스코어를 계산하도록 하는 수정된 가중모델 순위방법(Modified Weighting Model Rank; MWMR)을 제안한다. 제안한 방법의 유효성을 확인하기 위하여 316명의 화자를 대상으로 하여 인식실험을 실시한 결과, 학습 프레임이 10,000일 경우, MWMR 방법에서 $98.1\%$의 화자 인식률을 얻어 WMR 방법에 비해 약 $2.0\%$의 향상된 인식결과를 보여 제안한 방법의 유효성을 확인할 수 있었다.

• Korean Journal of Mathematics
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• 제15권2호
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• pp.135-148
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• 2007

We prove the stability of generalized Jensen's equations in a Hilbert module over a unital $C^*$-algebra. This is applied to show the stability of a projection, a unitary operator, a self-adjoint operator, a normal operator, and an invertible operator in a Hilbert module over a unital $C^*$-algebra.

• Journal of Environmental Impact Assessment
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• 제33권4호
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• pp.155-163
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• 2024

The purpose is to explore the meaning of the open space land use space pattern from the perspective of urban heat reduction using the land-use scenario. The employed methods are as follows: (1) to calculate the cooling capacity Index for each of five land use scenarios, using the InVEST Urban Cooling Model, (2) to calculate open space entropy & morphological spatial pattern for each land use scenario, using the Guidos Spatial Pattern Toolbox, and (3) to perform a Spearman rank correlation analysis between the InVEST and Guidos results. It is found that the rank correlation is moderate between the cooling capacity Index and the open space area ratio (rho=0.50). However, other relations are low. It is observed that only the total amount of open space is likely to have a meaning from the perspective of urban heat reduction, and that other open space location spatial patterns may not have much meaning from the perspective of urban thermal environment management.

• Korean Circulation Journal
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• 제53권9호
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• pp.606-618
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• 2023

Background and Objectives: The prognostic or safety implication of renin-angiotensin-aldosterone system inhibitors (RASi) in hypertrophic cardiomyopathy (HCM) are not well established, mainly due to concerns regarding left ventricular outflow tract (LVOT) obstruction aggravation. We investigated the implications of RASi in a sizable number of HCM patients. Methods: We enrolled 2,104 consecutive patients diagnosed with HCM in 2 tertiary university hospitals and followed up for five years. RASi use was defined as the administration of RASi after diagnostic confirmation of HCM. The primary and secondary outcomes were all-cause mortality and hospitalization for heart failure (HHF). Results: RASi were prescribed to 762 patients (36.2%). During a median follow-up of 48.1 months, 112 patients (5.3%) died, and 94 patients (4.5%) experienced HHF. Patients using RASi had less favorable baseline characteristics than those not using RASi, such as older age, more frequent history of comorbidities, and lower ejection fraction. Nonetheless, there was no difference in clinical outcomes between patients with and without RASi use (log-rank p=0.368 for all-cause mortality and log-rank p=0.443 for HHF). In multivariable analysis, patients taking RASi showed a comparable risk of all-cause mortality (hazard ratio [HR], 0.70, 95% confidence interval [CI], 0.43-1.14, p=0.150) and HHF (HR, 1.03, 95% CI, 0.63-1.70, p=0.900). In the subgroup analysis, there was no significant interaction of RASi use between subgroups stratified by LVOT obstruction, left ventricular (LV) ejection fraction, or maximal LV wall thickness. Conclusions: RASi use was not associated with worse clinical outcomes. It might be safely administered in patients with HCM if clinically indicated.

• Bulletin of the Korean Mathematical Society
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• 제39권2호
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• pp.289-297
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• 2002

It was shown by L. Polterovich ([3]) that if L is a totally real submanifold of a symplectic manifold $(M,\omega)$ and L is parallelizable then L is normal. So we try to find an answer to the question of whether there is a compatible almost complex structure J on the symplectic vector bundle $TM$\mid$_{L}$ such that $TL{\cap}JTL=0$ assuming L is normal and parallelizable. Although we could not reach an answer, we observed that the claim holds at the vector space level. And related to the question, we showed that for a symplectic vector bundle $(M,\omega)$ of rank 2n and $E=E_1{\bigoplus}E_2$, where $E=E_1,E_2$are Lagrangian subbundles of E, there is an almost complex structure J on E compatible with ${\omega}$ and $JE_1=E_2$. And finally we provide a necessary and sufficient condition for a given embedding into a symplectic manifold to be normal.

• Science of Emotion and Sensibility
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• 제9권spc3호
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• pp.277-286
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• 2006

This study evaluates how much D/H and enclosed effects are closely related with each other centering around the spaces of cities in Japan. The partial ranks of the degree of angle in D/H and of the enclosure of the real spaces which the experimenter feels are measured through the method of partial rank correlation analysis on the sane objects. The result shows that all 42 samples(0.49), 25 interior space samples(0.63), and 17 exterior samples(0.59) are analysed to be less correlated. Seen above, there is limit to explaining modern spaces with the degree of angle in D/H. The result reveals that the space structure of modem cities consists of a lot more complex elements, so it is not suitable to evaluate the spaces of cities with the past theories of D/H and enclosed effect. Therefore, to evaluate the enclosed effect, a new evaluation model and a study of influential elements of city spaces and enclosed effect should be developed.