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1.
Appl Opt ; 57(1): A101-A117, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29328135

RESUMO

We study optical technologies for viewer-tracked autostereoscopic 3D display (VTA3D), which provides improved 3D image quality and extended viewing range. In particular, we utilize a technique-the so-called dynamic fusion of viewing zone (DFVZ)-for each 3D optical line to realize image quality equivalent to that achievable at optimal viewing distance, even when a viewer is moving in a depth direction. In addition, we examine quantitative properties of viewing zones provided by the VTA3D system that adopted DFVZ, revealing that the optimal viewing zone can be formed at viewer position. Last, we show that the comfort zone is extended due to DFVZ. This is demonstrated by a viewer's subjective evaluation of the 3D display system that employs both multiview autostereoscopic 3D display and DFVZ.

2.
J Integr Neurosci ; 16(3): 255-273, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28891514

RESUMO

Due to the recent explosion in various forms of 3D content, the evaluation of such content from a neuroscience perspective is quite interesting. However, existing investigations of cortical oscillatory responses in stereoscopic depth perception are quite rare. Therefore, we investigated spatiotemporal and spatio-temporo-spectral features at four different stereoscopic depths within the comfort zone. We adopted a simultaneous EEG/MEG acquisition technique to collect the oscillatory responses of eight participants. We defined subject-specific retinal disparities and designed a single trial-based stereoscopic viewing experimental paradigm. In the group analysis, we observed that, as the depth increased from Level 1 to Level 3, there was a time-locked increase in the N200 component in MEG and the P300 component in EEG in the occipital and parietal areas, respectively. In addition, initial alpha and beta event-related desynchronizations (ERD) were observed at approximately 500 to 1000 msec, while theta, alpha, and beta event-related synchronizations (ERS) appeared at approximately 1000 to 2000 ms. Interestingly, there was a saturation point in the increase in cognitive responses, including N200, P300, and alpha ERD, even when the depth increased only within the comfort zone. Meanwhile, the magnitude of low beta ERD decreased in the dorsal pathway as depth increased. From these findings, we concluded that cognitive responses are likely to become saturated in the visual comfort zone, while perceptual load may increase with depth.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Percepção de Profundidade/fisiologia , Eletroencefalografia , Magnetoencefalografia , Sincronização Cortical , Eletroencefalografia/métodos , Potenciais Evocados , Feminino , Humanos , Magnetoencefalografia/métodos , Masculino , Percepção de Movimento/fisiologia , Imagem Multimodal/métodos , Estimulação Luminosa/métodos , Processamento de Sinais Assistido por Computador , Adulto Jovem
3.
Appl Ergon ; 62: 158-167, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28411726

RESUMO

Recent advances in three-dimensional (3D) video technology have extended the range of our experience while providing various 3D applications to our everyday life. Nevertheless, the so-called visual discomfort (VD) problem inevitably degrades the quality of experience in stereoscopic 3D (S3D) displays. Meanwhile, electroencephalography (EEG) has been regarded as one of the most promising brain imaging modalities in the field of cognitive neuroscience. In an effort to facilitate comfort with S3D displays, we propose a new wellness platform using EEG. We first reveal features in EEG signals that are applicable to practical S3D video systems as an index for VD perception. We then develop a framework that can automatically determine severe perception of VD based on the EEG features during S3D video viewing by capitalizing on machine-learning-based braincomputer interface technology. The proposed platform can cooperate with advanced S3D video systems whose stereo baseline is adjustable. Thus, the optimal S3D content can be reconstructed according to a viewer's sensation of VD. Applications of the proposed platform to various S3D industries are suggested, and further technical challenges are discussed for follow-up research.


Assuntos
Percepção de Profundidade , Imageamento Tridimensional/efeitos adversos , Transtornos da Visão/fisiopatologia , Percepção Visual/fisiologia , Adulto , Comportamento do Consumidor , Eletroencefalografia , Humanos , Imageamento Tridimensional/instrumentação , Masculino , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte , Gravação em Vídeo , Transtornos da Visão/etiologia , Adulto Jovem
4.
Neurosignals ; 24(1): 102-112, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27771723

RESUMO

BACKGROUND/AIMS: In exploring human factors, stereoscopic 3D images have been used to investigate the neural responses associated with excessive depth, texture complexity, and other factors. However, the cortical oscillation associated with the complexity of stereoscopic images has been studied rarely. Here, we demonstrated that the oscillatory responses to three differently shaped 3D images (circle, star, and bat) increase as the complexity of the image increases. METHODS: We recorded simultaneous EEG/MEG for three different stimuli. Spatio-temporal and spatio-spectro-temporal features were investigated by non-parametric permutation test. RESULTS: The results showed that N300 and alpha inhibition increased in the ventral area as the shape complexity of the stereoscopic image increased. CONCLUSION: It seems that the relative disparity in complex stereoscopic images may increase cognitive processing (N300) and cortical load (alpha inhibition) in the ventral area.

5.
Allergy Asthma Immunol Res ; 8(2): 146-55, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26739408

RESUMO

PURPOSE: Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. METHODS: A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. RESULTS: A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I²=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity. CONCLUSIONS: This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required.

6.
Allergol Int ; 65(2): 186-191, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26666496

RESUMO

BACKGROUND: Some western countries recently have shown a slowdown in the incidence of allergic diseases after worldwide increasing trends, but there are few data from Asian populations concerning changing trend of allergic diseases. We evaluated the recent trends in the prevalence of asthma and other allergic diseases in Korea. METHODS: From the database of Korean National Health Insurance, a nationwide diagnostic data from 2009 to 2014 were extracted and the national prevalence was analyzed. RESULTS: The prevalence per 1000 people of atopic dermatitis, allergic rhinitis, and asthma in 2014 was 19.0, 133.1, and 36.3, respectively. The prevalence of three diseases was highest in the age group under 10 as, 95.0, 384.1, and 132.1 per 1000 people, while the prevalence in the over-10-year-group was only 11.6, 109.5, and 27.3, respectively. The prevalence of atopic dermatitis and allergic rhinitis gradually decreased with older age, but the prevalence of asthma showed a re-increasing pattern from the age group 30-39 and reached another peak for the age group 70-79. During the study period, the prevalence of asthma and atopic dermatitis showed decreasing tendency. In contrast, the prevalence of allergic rhinitis steadily increased until 2013, especially in the age group under 10. CONCLUSIONS: The national prevalence of atopic dermatitis, and asthma did not show noticeable increase any more in Korea. However, the prevalence of allergic rhinitis still on the rise until recently, especially in the age group under 10. This is the first report in Asia suggesting a slowdown of the incidence of allergic diseases.


Assuntos
Hipersensibilidade/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Feminino , Custos de Cuidados de Saúde , Humanos , Hipersensibilidade/diagnóstico , Masculino , Pessoa de Meia-Idade , Vigilância da População , Prevalência , República da Coreia/epidemiologia , Estudos Retrospectivos , Adulto Jovem
7.
Asia Pac Allergy ; 5(2): 123-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25938077

RESUMO

Eosinophilic myocarditis is a condition resulting from various eosinophilic diseases, including helminth infection, drug hypersensitivity, systemic vasculitis or idiopathic hypereosinophilic syndromes. Clinical manifestations of eosinophilic myocarditis may vary from early necrosis to endomyocardial fibrosis. Eosinophilic myocarditis is one of the most fatal complications of hypereosinophilia. However, eosinophilic myocarditis has been rarely reported in the literature, particularly in Asia Pacific regions, reflecting the under-recognition of the disease among clinicians. Early recognition is crucial for improving clinical outcomes of eosinophilic myocarditis. Early administration of systemic corticosteroid is necessary in eosinophilic myocarditis regardless of underlying causes, as delayed treatment may result in fatal outcomes. In addition, differential diagnoses of underlying causes for eosinophilia are necessary to improve long-term outcomes.

8.
J Hazard Mater ; 221-222: 248-55, 2012 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-22572561

RESUMO

The present work evaluated the fertilizing value of struvite deposit recovered from semiconductor wastewater in cultivating Chinese cabbage. The fertilizing effect of struvite deposit was compared with that of commercial fertilizers: complex, organic and compost. Laboratory pot test results clearly showed that the growth of Chinese cabbage was better promoted when the struvite deposit was used than with organic and compost fertilizers even though complex fertilizer was the most effective in growing Chinese cabbage. It was revealed that potassium (K) was a key element in the determination of growth rate of Chinese cabbage. Also, the abundant nutrients such as nitrogen (N), phosphorus (P), K, calcium (Ca) and magnesium (Mg) were observed in the vegetable tissue of struvite pot. Specifically, P was the most-founded component in the vegetable tissue of struvite pot. Meanwhile, the utilization of struvite as a fertilizer led to the lowest accumulation of copper (Cu) and no detection of cadmium (Cd), arsenic (As), lead (Pb) and nickel (Ni) in the Chinese cabbage. It was found that the optimum struvite dosage for the cultivation of Chinese cabbage was 1.6 g struvite/kg soil. Based on these findings, it was concluded that the struvite deposits recovered from semiconductor wastewater were effective as a multi-nutrient fertilizer for Chinese cabbage cultivation.


Assuntos
Brassica/química , Fertilizantes , Compostos de Magnésio/química , Fosfatos/química , Semicondutores , Metais Pesados/análise , Microscopia Eletrônica de Varredura , Nitrogênio/análise , Fósforo/análise , Potássio/análise , Estruvita , Difração de Raios X
9.
Allergy Asthma Immunol Res ; 2(4): 247-53, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20885909

RESUMO

PURPOSE: Patient care based on asthma guidelines is cost-effective and leads to improved treatment outcomes. However, ineffective implementation strategies interfere with the use of these recommendations in clinical practice. This study investigated physicians' preferences for asthma guidelines, including content, supporting evidence, learning strategies, format, and placement in the clinical workplace. METHODS: We obtained information through a questionnaire survey. The questionnaire was distributed to physicians attending continuing medical education courses and sent to other physicians by airmail, e-mail, and facsimile. RESULTS: A total of 183 physicians responded (male to female ratio, 2.3:1; mean age, 40.4±9.9 years); 89.9% of respondents were internists or pediatricians, and 51.7% were primary care physicians. Physicians preferred information that described asthma medications, classified the disease according to severity and level of control, and provided methods of evaluation/treatment/monitoring and management of acute exacerbation. The most effective strategies for encouraging the use of the guidelines were through continuing medical education and discussions with colleagues. Physicians required supporting evidence in the form of randomized controlled trials and expert consensus. They preferred that the guidelines be presented as algorithms or flow charts/flow diagrams on plastic sheets, pocket cards, or in electronic medical records. CONCLUSIONS: This study identified the items of the asthma guidelines preferred by physicians in Korea. Asthma guidelines with physicians' preferences would encourage their implementation in clinical practice.

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