98 research outputs found

    A Novel Cloud Removal Method Based on Ihot and the Cloud Trajectories for Landsat Imagery

    Get PDF
    Cloud removal is significantly needed for enhancing the further utilization of Landsat imagery, since such optical remote sensing satellite images are inevitably contaminated by clouds. Clouds dynamically affect the signal transmission due to their different shapes, heights, and distribution. Generally, pixel replacement is the only and common method used to remove thick opaque clouds, and radiometric correction techniques has been widely adopted to remove the thin clouds. However, no methods can remove both thick and thin clouds at the same time. In this paper, a new method is proposed based on fitting “trajectory” of cloudy pixels with the help of IHOT spatially charactering clouds for pixel correction, which considers signal transmission including not only the additive reflectance from the clouds but also the energy attenuation when solar radiation passes through them. The experimental results show that the proposed approach performs effective removal for thick and thin clouds, and possesses the highest accuracy with the reference image, which can restore land cover information accurately

    Algebraic Structures of Neutrosophic Triplets, Neutrosophic Duplets, or Neutrosophic Multisets

    Get PDF
    Neutrosophy (1995) is a new branch of philosophy that studies triads of the form (, , ), where is an entity {i.e. element, concept, idea, theory, logical proposition, etc.}, is the opposite of , while is the neutral (or indeterminate) between them, i.e., neither nor .Based on neutrosophy, the neutrosophic triplets were founded, which have a similar form (x, neut(x), anti(x)), that satisfy several axioms, for each element x in a given set.This collective book presents original research papers by many neutrosophic researchers from around the world, that report on the state-of-the-art and recent advancements of neutrosophic triplets, neutrosophic duplets, neutrosophic multisets and their algebraic structures – that have been defined recently in 2016 but have gained interest from world researchers. Connections between classical algebraic structures and neutrosophic triplet / duplet / multiset structures are also studied. And numerous neutrosophic applications in various fields, such as: multi-criteria decision making, image segmentation, medical diagnosis, fault diagnosis, clustering data, neutrosophic probability, human resource management, strategic planning, forecasting model, multi-granulation, supplier selection problems, typhoon disaster evaluation, skin lesson detection, mining algorithm for big data analysis, etc

    Cloud removal from optical remote sensing images

    Full text link
    Optical remote sensing images used for Earth surface observations are constantly contaminated by cloud cover. Clouds dynamically affect the applications of optical data and increase the difficulty of image analysis. Therefore, cloud is considered as one of the sources of noise in optical image data, and its detection and removal need to be operated as a pre-processing step in most remote sensing image processing applications. This thesis investigates the current cloud detection and removal algorithms and develops three new cloud removal methods to improve the accuracy of the results. A thin cloud removal method based on signal transmission principles and spectral mixture analysis (ST-SMA) for pixel correction is developed in the first contribution. This method considers not only the additive reflectance from the clouds but also the energy absorption when solar radiation passes through them. Data correction is achieved by subtracting the product of the cloud endmember signature and the cloud abundance and rescaling according to the cloud thickness. The proposed method has no requirement for meteorological data and does not rely on reference images. The experimental results indicate that the proposed approach is able to perform effective removal of thin clouds in different scenarios. In the second study, an effective cloud removal method is proposed by taking advantage of the noise-adjusted principal components transform (CR-NAPCT). It is found that the signal-to-noise ratio (S/N) of cloud data is higher than data without cloud contamination, when spatial correlation is considered and are shown in the first NAPCT component (NAPC1) in the NAPCT data. An inverse transformation with a modified first component is then applied to generate the cloud free image. The effectiveness of the proposed method is assessed by performing experiments on simulated and real data to compare the quantitative and qualitative performance of the proposed approach. The third study of this thesis deals with both cloud and cloud shadow problems with the aid of an auxiliary image in a clear sky condition. A new cloud removal approach called multitemporal dictionary learning (MDL) is proposed. Dictionaries of the cloudy areas (target data) and the cloud free areas (reference data) are learned separately in the spectral domain. An online dictionary learning method is then applied to obtain the two dictionaries in this method. The removal process is conducted by using the coefficients from the reference image and the dictionary learned from the target image. This method is able to recover the data contaminated by thin and thick clouds or cloud shadows. The experimental results show that the MDL method is effective from both quantitative and qualitative viewpoints

    The Missouri Miner, October 01, 1981

    Get PDF
    https://scholarsmine.mst.edu/missouri_miner/3287/thumbnail.jp

    Bulloch Times

    Get PDF
    https://digitalcommons.georgiasouthern.edu/bulloch-news-issues/1739/thumbnail.jp

    Can current design and development management pedagogy respond better in reflecting industry needs?

    Get PDF
    The purpose of this study is to bring clarity and consistency to the academic field that concentrates on management of product design and development. The research explores the assumption that no common standards exist for the education of those wishing to assume a managerial position in that field. The findings have shown a significant lack of consistency in both the subjects offered as well as the naming of the subject in terms of the public presentation. As such, those who wish to enter the field, as well as those wishing to hire leadership, are met with dramatically varied educational background and degree titles. This study presents a review of all identified existing graduate programmes —of which there are 35 institutions worldwide, teaching 60 different courses, with 24 separate degree names. This research explores and identifies the most relevant courses in response to leaders in industry. In his work, Schön (1983) references relevancy in terms of competence that is valued in professional practise as opposed to knowledge taught in academia, and this thesis explores what is practiced and what should be taught. Three distinct groups within the USA were interviewed, including the following: 1) eleven educators responsible for these programme , 2) twenty design-centric industry leaders who hire managers for professional practice, and 3) ninety alumni who have graduated from one particular programme. The tacit knowledge of key leaders needs and the general references made to relevance over rigour are the impetus for the study. Valuing and addressing industry needs and ultimately recommending a course of action that aligns academic training with a more industry relevant content has been the overriding direction for this work. It is that debate that this research, for the first time, addresses the wants of industry, through clarifying eight specific courses to satisfy the need for trained graduate students in the role of management of product design and development within the context of the USA

    Hip deformities and femoroacetabular impingement

    Get PDF
    RESUMO: Conceptualmente, a conservação de uma estrutura anatómica é mais benéfica do que a sua substituição. No caso das articulações humanas, este conceito é particularmente importante face aos múltiplos problemas, ainda não resolvidos, relacionados com próteses e materiais usados na cirurgia ortopédica. Na articulação coxofemoral, o conceito de preservação, melhorando os parâmetros biomecânicos, assume uma complexidade técnica acrescida maioritariamente pelo facto de a circulação epifisária do fémur ser intra-articular e dada a proximidade de importantes estruturas neurovasculares. O conflito femoroacetabular (CFA) e a displasia acetabular no adulto jovem, são duas entidades patológicas comuns embora com múltiplas áreas ainda por investigar. A displasia infantil, não diagnosticada e não tratada, pode originar displasia acetabular residual na idade adulta e consequente sintomatologia e limitação funcional. O diagnóstico de CFA no adulto é baseado em critérios clínicos e radiográficos. Clinicamente apresenta-se igualmente com dor e limitação funcional. Radiologicamente, dois subtipos de CFA são habitualmente reconhecidos, o tipo Cam (mecanismo patológico decorrente de asfericidade femoral) e o tipo Pincer (por hipercobertura acetabular). Embora com padrões diferentes de envolvimento articular, os dois mecanismos de conflito condicionam dor, lesão estrutural do labrum e condropatia. Atualmente, a morfologia Cam é considerada como um dos principais fatores de risco morfológico que contribuem para o desenvolvimento de osteoartrose precoce da coxofemoral, eventualmente com necessidade de recurso a prótese total da anca. Apesar de a investigação inicial na área da cirurgia conservadora da anca ter documentado bons resultados cirúrgicos, atualmente a controvérsia é francamente superior ao consenso relativamente à melhor abordagem diagnóstica e terapêutica. Caracteristicamente, apesar de em muitos casos os achados clínicos e radiológicos serem inequívocos para o diagnóstico de CFA, um número substancial de doentes apresenta achados frustes ou equívocos. Por outro lado, múltiplos estudos descreveram uma alta prevalência de morfologia compatível com CFA na população adulta e em indivíduos saudáveis assintomáticos. Atualmente, não existe uma ferramenta de imagem ideal que facilite a alocação fidedigna de todos os doentes a um grupo patológico específico ou, por outro lado, exclua com confiança o diagnóstico de conflito. No entanto, os parâmetros de imagem podem ser utilizados para analisar e descrever as diferentes características morfológicas da anca e adicionalmente confirmar o diagnóstico de CFA. Esta tese enfoca, por um lado, a avaliação da morfologia coxofemoral em diferentes populações, investigando quais articulações estão mais predispostas ao desenvolvimento de sintomas e, por outro, os resultados do tratamento cirúrgico de uma coorte com o diagnóstico de CFA tipo Cam. Especificamente, a investigação efetuada: 1) examinou características morfológicas específicas da coxofemoral em diferentes populações (sintomáticas ou não sintomáticas); 2) desenhou um modelo estatístico baseado em preditores anatómicos no sentido de estabelecer as articulações em risco de desenvolvimento sintomático, incorporando geometrias articulares específicas e parâmetros espinhopélvicos; e 3) analisou os resultados de terapêutica cirúrgica numa coorte de doentes com o diagnóstico CFA tipo Cam. Durante a progressão clínica na área da imagiologia e nesta área patológica em particular, apercebemo-nos da existência de múltiplas lacunas de conhecimento que procurámos colmatar com a investigação agora publicada e descrita nesta tese. A sistematização por capítulos reflete precisamente a necessidade de abordar a questão em áreas de conhecimento, simultaneamente distintas e complementares. Os seis capítulos desta tese abrangem o espectro clínico desde o diagnóstico até ao tratamento da anca jovem. De modo a apresentar os objetivos desta tese numa sequência lógica, desde a anatomia geral até à morfologia e tratamento específicos do CFA, a análise da anca assintomática será descrita em primeiro lugar seguida pela análise da relação anatomoclínica entre morfologia articular e sintomas. Por último será abordada a terapêutica do doente sintomático. Na PARTE I, apresentamos os tópicos essenciais para compreender a abrangência do espectro da presente tese, designadamente a relevância e a contemporaneidade do tema “CFA” e adicionalmente o enquadramento anatómico, morfológico e vascular desta articulação. O Capítulo 1 é dedicado ao desenvolvimento e morfogénese da anca. No Capítulo 2, sublinhamos a importância e o papel da imagem através de uma revisão enfocada nas perspetivas atuais e futuras sobre este tópico (Artigo I). No Capítulo 3, realizamos uma revisão sistemática da literatura no sentido de descrever o estado da arte com foco na prevalência da morfologia de CFA em populações assintomáticas e sintomáticas. Este capítulo destaca as múltiplas lacunas de conhecimento relativas ao papel da morfologia da articulação coxofemoral na patogénese do CFA (Artigo II). Com base nesta parte introdutória, abordamos seguidamente os objetivos da presente tese, gerais e específicos, na PARTE II.Na PARTE III, descrevemos o corpo da investigação clínica original efetuada. O Capítulo 4 é dedicado à caracterização detalhada da morfologia da anca, designadamente óssea e vascular. A morfologia coxofemoral foi quantificada utilizando software com capacidade de semi-automatização analítica, permitindo estudar a prevalência e relação entre as diferentes morfologias articulares e o género, dominância e simetria articular (Artigo III). A morfologia Cam foi ainda alvo de caracterização mais aprofundada, através do desenvolvimento de um novo parâmetro quantitativo com potencialidade diagnóstica e de planeamento cirúrgico/ /prognóstico, primariamente testado numa coorte assintomática (Artigo IV) e seguidamente também em doentes com indicação cirúrgica (Artigo V). Na nossa atividade clínica diária apreciámos a necessidade urgente de melhor caracterizar a topografia da deformidade Cam e a respetiva relação com as artérias nutritivas da epífise femoral. A impressão clínica referida sugeria que a morfologia Cam frequentemente se estendia posteriormente ao quadrante póstero-superior, intersectando a região retinacular vascular. No entanto, por imagem a natureza arterial destas estruturas nunca havia sido confirmada. Por esta razão, a importância do parâmetro mencionado foi sublinhada e comprovada no estudo cadavérico com avaliação topográfica vascular do fémur proximal (Artigo VI). No Capítulo 5 testámos múltiplos parâmetros imagiológicos e respetivas variações/relações com diferentes morfologias coxofemorais, no sentido de identificar as articulações com risco clínico aumentado de desenvolvimento sintomático. Para este fim efetuámos estudos baseados em computação avançada com modelação estatística (Artigo VII) e também em ressonância magnética (RM) tridimensional (Artigo VIII). O Capítulo 6 descreve as opções de tratamento (Artigo IX) e os resultados clínicos num estudo clínico de uma coorte com follow-up mínimo de 2 anos, comparando a abordagem cirúrgica aberta e artroscópica (Artigo X). Os resultados dos diferentes capítulos estão sumarizados na PARTE IV, onde apresentamos a síntese geral, a discussão crítica dos resultados obtidos à luz da literatura atual e finalmente as conclusões relevantes. As oportunidades futuras de investigação são igualmente abordadas neste capítulo. Em resumo o trabalho constante da presente tese sugere: Primeiro, que a avaliação imagiológica detalhada da morfologia coxofemoral é essencial no sentido de compreender aprofundadamente não só a própria articulação como também a morfologia pélvica (Artigo I). Segundo, paradoxalmente, a definição clínica de um caso patológico e das diferentes entidades relacionadas, é ainda inexistente. Os parâmetros quantitativos e qualitativos que comummente estão associados com CFA tipo Pincer e Cam são francamente frequentes em diferentes populações (sintomáticas e assintomáticas) (Artigo II).Terceiro, em populações assintomáticas adultas, os intervalos de referência específicos para os parâmetros quantitativos associados a morfologia de CFA e displasia são mais latos e com limites superiores mais elevados do que os atualmente utilizados na prática clínica (Artigo III). A morfologia femoral bem como os epicentros/magnitudes das deformidades Cam são específicos de género, observando-se maiores valores de ângulo alfa e ómega em indivíduos do sexo masculino (Artigo IV). Quarto, é frequente a interseção entre a extensão póstero-superior da deformidade Cam e a convergência epifisária das estruturas vasculares retinaculares observadas em RM, aspetos que se revestem de primordial importância no planeamento cirúrgico. Adicionalmente a extensão radial da deformidade Cam (ângulo ómega) está significativamente mais relacionada com a sintomatologia clínica pré-cirúrgica do que o parâmetro mais comummente utilizado na prática clínica (ângulo alfa) (Artigo V). A origem das estruturas vasculares observadas por RM na prega retinacular é inequivocamente arterial, sendo que abrange uma extensão mais anterior do que classicamente assumido (Artigo VI). Quinto, as geometrias ovalares (em detrimento das morfologias esféricas e elipsoides) são melhor representativas de ambas as superfícies articulares da coxofemoral, designadamente do fémur e acetábulo, bem como das ancas sintomáticas que clinicamente exibem sinais de CFA (Pincer, Cam e misto) (Artigo VII). Indivíduos com maiores deformidades Cam, aspetos de hipocobertura acetabular e acentuação da anteflexão pélvica apresentam uma maior probabilidade de desenvolverem sintomas articulares (Artigo VIII). Esta observação é crítica, dado que fornece, na prática clínica, informação essencial acerca da potencial predisposição para fenómenos de exacerbação sintomática futura, permitindo desta forma instituição de medidas terapêuticas/preventivas adequadas. Na perspetiva do doente, um diagnóstico precoce e preciso, pode conceptualmente prevenir, numa primeira fase, alterações condropáticas articulares e, numa segunda instância, progressão para artrose estabelecida. Sexto, documentamos resultados clínicos e funcionais significativamente favoráveis quando comparamos a abordagem artroscópica e aberta no tratamento cirúrgico da deformidade Cam, sendo de observar que o género feminino está associado a menor score funcional na avaliação pré-operatória (Artigos IX e X). Futuramente, a imagiologia e a cirurgia conservadora da anca irão desenvolver-se conjuntamente e em paralelo com novos e maiores desafios. A descrição de novos parâmetros analíticos para avaliação da patoanatomia coxofemoral, associada à inovação tecnológica crescente e à implementação da inteligência artificial, impõem uma evolução clínica oposta à assunção de classificações patológicas demasiadamente simplistas. Nesse sentido a existência de guidelines de diagnóstico e terapêutica mais efetivas e baseadas na evidência, que nos levem além da pura diferenciação entre CFA e displasia, são urgentes. A história natural das deformidades Cam e Pincer, sintomáticas ou assintomáticas, é ainda grandemente desconhecida, assumindo-se como uma área determinante de investigação no que concerne ao diagnóstico, terapêutica e prognóstico.ABSTRACT: Conceptually, the preservation of a human anatomical structure makes more sense than its replacement. This concept is even more striking in the case of human joints due to the multitude of unsolved problems related to implants used in orthopaedic surgery. With respect to the hip, joint preservation assumes an increased technical complexity when compared to other joints; this is due to two main reasons: the intra-articular epiphyseal circulation of the femur and the proximity of large neurovascular structures. Femoroacetabular impingement (FAI) and acetabular dysplasia (DHD) in young adults are two common but poorly characterised pathological entities. If undiagnosed and untreated, dysplasia in childhood may lead to residual DHD in young adults, as diagnosed on radiographs, and may also give rise to symptoms such as hip pain and restricted range of motion. The diagnosis of FAI in adults is based on clinical and imaging criteria. The most frequently noticed symptoms of FAI include hip pain and restricted function. Radiologically, two main subtypes of FAI are recognised: The Cam-type, with the pathoanatomical mechanism located on the femoral side, and the Pincertype on the acetabular side. Although with different pathological patterns, both types cause pain and articular damage of the labrum and cartilage. While Cam-type FAI is believed to be a major contributing factor to the early onset of hip osteoarthritis (OA), which eventually requires a total hip replacement, the relationship of other shapes and morphologies with OA are still under debate. Despite the initial promising reports on outcomes following surgical management of these conditions, the best approach to diagnose and manage them still remains controversial. Although for some patients there are unambiguous clinical and imaging findings of FAI, for a substantial number of patients there are minimal or intermediate findings. Moreover, several studies have reported a high prevalence of FAI morphology among the “normal” population and in asymptomatic healthy individuals. At present, there is no adequate imaging tool to facilitate the reliable allocation of all patients into the correct diagnostic group or to confidently rule out diagnosis. However, imaging parameters can be used to describe different hip morphological characteristics and additionally confirm or preclude the diagnosis of FAI.This thesis focuses on assessing hip morphology in different populations by investigating which specific joints are more prone to developing symptoms and by evaluating treatment outcomes of a FAI cohort. Specifically, this research concentrates on the following: 1) examining population-specific (symptomatic and non-symptomatic) characteristics of hip morphology; 2) developing an anatomic-based model to establish “at-risk” hip joints, incorporating subject-specific hip geometries and spinopelvic parameters and 3) investigating treatment outcomes in a Cam-type FAI cohort. In our clinical progression in imaging and in this particular area of pathology, we became aware of the existence of several gaps that we sought to fill with the now published research hereby described. The systematisation by chapters precisely reflects the need to address the issue in simultaneously distinct and complementary areas of knowledge. This thesis consists of six chapters, which cover the entire spectrum from the diagnosis to treatment of the young hip. To present the aims of this thesis in a sequential manner from general morphology to more specific FAI-related topics, the analysis of the asymptomatic hip will be presented first, followed by how joint morphology is associated with symptoms and, finally, will conclude with treatment. In PART I, we introduce the topics that are relevant to understand the full scope of our thesis; we aim to accomplish this by addressing the relevance and contemporariness of the “FAI” theme and by describing the general and vascular anatomy of the hip. Chapter 1 is devoted to hip development and morphogenesis. In Chapter 2, we address the importance of imaging by conducting a thorough review of current and future perspectives on this topic (Paper I). In Chapter 3, we perform a systematic review of the literature to write a state-of-the-art overview, focussing on asymptomatic and symptomatic FAI morphology prevalence and highlighting the multiple gaps in knowledge regarding the role of hip morphology in the pathogenesis of FAI (Paper II). Building on the first part, we address the rationale and aims of this thesis in PART II. In PART III, we describe the original research that was performed and published. Chapter 4 focusses on the detailed characterisation of hip morphology, both osseous and vascular. Bony hip morphology was quantified using a semi-automated software, which allows to robustly study in detail shape variants in an asymptomatic population and their relationship with sex, side and limb dominance (Paper III). Cam morphology was further defined by developing a novel quantitative parameter, with diagnostic and treatment planning capabilities using a cohort of both asymptomatic individuals (Paper IV) and patients undergoing surgery (Paper V). Moreover, we felt the need to better characterise the topography of the deformity and its relationship with the nourishing arteries of the femoral head, as Cam morphology frequently has a posterior a bstr extension that overlaps the retinacular vascular structures. However, its arterial origin has never been described or confirmed in the literature. For this reason, the importance of the aforementioned parameter has been outlined by the cadaveric arterial topographic study of the proximal femur (Paper VI). In Chapter 5, we test multiple parameters and their associated shape variants to detect which ones allow identifying a risk-increased joint in various populations. To this end, we use both advanced computing for shape modelling (Paper VII) and three dimensional (3D) magnetic resonance imaging (MRI) (Paper VIII). Chapter 6 describes the various treatment options (Paper IX) and outcomes in a cohort clinical study, comparing open surgery with arthroscopic surgery in terms of treating Cam deformities (Paper X). The results of the aforementioned chapters are summarised in PART IV, presenting the general synthesis, discussing the results in the light of current literature and detailing the conclusions of this thesis. The scope of potential future research within this field is also presented in this chapter. In brief, this thesis suggests the following: First, detailed imaging assessment of hip morphology is paramount to better understanding both the hip joint and pelvic morphology (Paper I). Second, the case definitions of different morphologies and clinical entities are missing as far as FAI and related disorders are concerned. Qualitative and quantitative radiographic findings thought to be associated with Cam- and Pincer-type FAI, as well as the coexistence between them, are quite common among different populations (Paper II). Third, in adult asymptomatic populations, sex-specific reference intervals for hip measurements for DHD and FAI morphology are wider than currently accepted values (Paper III). Moreover, femoral morphology with distinct Cam magnitudes and epicentres is also sex-specific, with higher mean alpha angle (α°) and omega angle (Ω°) values seen in males (Paper IV). Forth, Cam deformity frequently overlaps with the retinacular vascular structures seen in an MRI; this finding has practical surgical relevance. Additionally, the radial extension of the Cam deformity (Ω°) is more significantly associated with the patients’ symptoms prior to surgery than the α° (paper V). The origin of the vascular structures seen in the retinacular fold is unequivocally arterial in nature, and these structures have a more anterior distribution than classically assumed (Paper VI). Fifth, ovoid geometries are more representative of both articular surfaces of the hip joint as well as of Cam, Pincer and mixed impinged hips when compared to spherical or ellipsoidal shapes (Paper VII). Individuals with larger Cam deformities, decreased acetabular coverage and increased pelvic anteflexion are more likely to experience hip symptoms (Paper VIII). This provides clinicians with indications of how the pathology exacerbates, allowing them to perform the correct clinical assessments and proceed with the correct form of care. From a patient’s perspective, an early and accurate diagnosis could prevent cartilage degradation and progression to OA. Sixth, similar outcomes and significant functional improvement are observed when comparing open and arthroscopic surgery in the treatment of Cam deformities (follow-up time of two years). It should be noted that the female gender was associated with poor hip function in the preoperative evaluation (papers IX and X). Looking ahead, imaging and hip preserving surgery (HPS) will evolve hand-in-hand in the face of new and greater challenges. The increasing number of analytic parameters describing hip joint pathomorphologies as well as new sophisticated 3D imaging-analysis together with emerging artificial intelligence-based technologies have transported us beyond simple classification systems. Moreover, more reliable diagnostic and treatment guidelines that go beyond differentiation into pure FAI and dysplasia are paramount. The largely unknown natural course of both hips with symptomatic FAI and asymptomatic individuals continues to present research opportunities as far as diagnosis, treatment and prognosis are concerned

    Large space structures and systems in the space station era: A bibliography with indexes (supplement 03)

    Get PDF
    Bibliographies and abstracts are listed for 1221 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and June 30, 1991. Topics covered include large space structures and systems, space stations, extravehicular activity, thermal environments and control, tethering, spacecraft power supplies, structural concepts and control systems, electronics, advanced materials, propulsion, policies and international cooperation, vibration and dynamic controls, robotics and remote operations, data and communication systems, electric power generation, space commercialization, orbital transfer, and human factors engineering
    corecore