Prior Knowledges Research Articles

Adaptive color deconvolution for histological WSI normalization

Background and ObjectiveColor consistency of histological images is significant for developing reliable computer-aided diagnosis (CAD) systems. However, the color appearance of digital histological images varies across different specimen preparations, staining, and scanning situations. This variability affects the diagnosis and decreases the accuracy of CAD approaches. It is important and challenging to develop effective color normalization methods for digital histological images. MethodsWe proposed a novel adaptive color deconvolution (ACD) algorithm for stain separation and color normalization of hematoxylin-eosin-stained whole slide images (WSIs). To avoid artifacts and reduce the failure rate of normalization, multiple prior knowledges of staining are considered and embedded in the ACD model. To improve the capacity of color normalization for various WSIs, an integrated optimization is designed to simultaneously estimate the parameters of the stain separation and color normalization. The solving of ACD model and application of the proposed method involves only pixel-wise operation, which makes it very efficient and applicable to WSIs. ResultsThe proposed method was evaluated on four WSI-datasets including breast, lung and cervix cancers and was compared with 6 state-of-the-art methods. The proposed method achieved the most consistent performance in color normalization according to the quantitative metrics. Through a qualitative assessment for 500 WSIs, the failure rate of normalization was 0.4% and the structure and color artifacts were effectively avoided. Applied to CAD methods, the area under receiver operating characteristic curve for cancer image classification was improved from 0.842 to 0.914. The average time of solving the ACD model is 2.97 s. ConclusionsThe proposed ACD model has prone effective for color normalization of hematoxylin-eosin-stained WSIs in various color appearances. The model is robust and can be applied to WSIs containing different lesions. The proposed model can be efficiently solved and is effective to improve the performance of cancer image recognition, which is adequate for developing automatic CAD programs and systems based on WSIs.

An augmented PID control structure to compensate for valve stiction

It is well-known that valve stiction causes sustained oscillations on process variables when a traditional PID controller is implemented in the feed-back loop. In the literature, there is a vast collection of solid techniques to compensate for valve stiction which employ different approaches and require various prior knowledges on process and stiction dynamics. Among others methods, PID retuning or changes to the traditional algorithm and structure of PID can be useful solutions to mitigate or remove negative effects of valve stiction. Appropriate controller retuning can reduce significantly amplitude and frequency of oscillation, but it cannot remove the problem permanently. Modifying traditional PID algorithm or augmenting standard structure of the controller are also robust approaches for the scope. This paper briefly revises some PID-based stiction compensation techniques and illustrates a new version of stiction-aware PID. A standard PI(D) controller is augmented with a two-move compensator and, by monitoring the control error, it is able to remove effect of valve stiction and to guarantee set-point tracking and disturbance rejection. This PID-based structure requires the estimation of controller output associated with the desired valve position at steady-state and the estimate of valve stiction parameters.

La ciudad: enlace de vivencias y conocimientos escolares

El presente artículo tiene por objetivo valorar las vivencias de los estudiantes como recursos para enseñar conceptos clave de la geografía en la educación básica primaria. Las vivencias hacen parte de los conocimientos previos que el educando expresa, y con base en su análisis construye conceptos fundamentales de la geografía escolar para lograr un aprendizaje significativo de estos. El artículo expone las estrategias didácticas dentro del modelo constructivista que la autora ha aplicado y considera como el modelo más efectivo para lograr aprendizajes duraderos, y que facilita la construcción de redes conceptuales de la disciplina geográfica.

Development of CALP through ICT and Lexical Approach in Second Generation Foreign Students

The public Italian School is a multicultural school: 51% of foreign students were born in Italy or arrived before starting primary school and their academic performance is lower than average, as verified by the Ministry of Education (MIUR 2015) and confirmed by a research group of Genoa University that assessed pupils’ prior knowledge in an elementary school. Consequently two research questions have been formulated:;1. A second generation foreign student has the same CALP (Cognitive Academic Language Proficiency, Cummins 1979) as an Italian student? 2. Can the development of CALP both in Italian and Spanish give significant results? If so, which ones? The project LI.LO (acronym of Lingua Italiana, Lingua di Origine) aims to study relations between heritage language and second language acquisition in CALP. It also has the purpose to build bilingualism programs in the public middle school by using ICT (Information and Communication Technologies) in order to improve academic proficiency and study skills in both languages. This paper wants to show the two basic phases of the project: in the first phase the researchers collected data about students’ linguistic prior knowledges and skills, showing a better competence in the section of the pre-test related to the lexicon. The analysis of the first phase was used to consider aims and guidelines for the bilingual course LI.LO. The method has been the Lexical Approach (Lewis, 1993, 1997) . Secondly the researchers opened the course on a platform CLAT/Clire, in which they put materials in both languages. ICT were used in many activities. In the contribute it will be shown analysis, results and further perspectives of the project.

Why does the subject speak? Prejudgement in fieldwork with Naxalites and Hindu rioters

This article explores the shifting trajectory of dramaturgical encounters with ‘subjects’ in two disparate contexts of violence in contemporary India: Naxalites in Jharkhand and Bihar; and participants in the 2002 riots in Gujarat. It argues that why (and thereby what) the subject speaks has to be located within the larger text of performances in the ‘field’, involving the prejudgement (in a Gadamerian sense) of both researcher and subject. Limits and possibilities to prior knowledges of both predetermine outcomes of interaction and inform the enterprise of doing theory in troubled contexts.

Single server queueing model with Gumbel distribution using Bayesian approach

Bayesian methodology is an important technique in statistics, and especially in mathematical statistics. It consists of the sample information along with the prior information available about the parameter before the sample has been observed. This paper exhibits the estimation of the parameters of queueing model with inter-arrival time and service time which follows Gumbel distribution. Bayesian procedure is applied to obtain the estimation of the model parameters and the tra c intensity of queueing model based on the informative and the non-informative prior knowledges. In this paper, the Bayesian estimates are carried out by numerically and graphically with the help of Markov Chain Monte Carlo (MCMC) simulation technique, particularly in Gibbs sampling algorithm.

‘I act this way because why?’ Prior knowledges, teaching for change, imagining new masculinities

This article begins by outlining some of the prior knowledges brought by undergraduate students to an introduction to gender studies class in the Women’s and Gender Studies Department at the University of the Western Cape, South Africa. I show that, at the beginning of the course, students clearly understand gender to refer to women and femininity, imagining femininity (but not masculinity) to be responsive to social change. I suggest that, in the face of these prior knowledges, it is important to focus on masculinity as performance, as a cultural artefact and one that is deeply harmful to South African men. Student experiences of this teaching and learning suggest that it offers possibilities for imagining men as allies and beneficiaries – rather than enemies – in the struggle for gender equity.

Legitimate Peripheral Participation (LPP) – The case for Recognition of Prior Learning sites and knowledges in South Africa's transforming education system

By definition and purpose, education is the development of human capital towards meeting the individual and social needs of learners and their societies. This transdisciplinary collaboration parallels the underpinning principle of Lave and Wenger's Legitimate Peripheral Participation ( Lave & Wenger, 1990) to South Africa's post-colonial legitimation of alternative sites and enskilment canons. Central to both is legitimation of knowledge acquisition from communities of practice or sites and ‘knowers’ ( Mphahlele, 1992) ‘outside formal institutions’ of teaching/learning. Considered and termed ‘informal’ and by deduction, less legitimate for meritorious enskilment, the South African Qualifications Authority (1995, 2002) decrees a transformative paradigm and method of validating these sites and their skills production. SAQA highlights the fact that the pedagogical approach of such sites is context- and learner-centred with demonstrable socially valuable skills. This post-colonial mandate thus centres the Recognition of Prior Learning (RPL) as an acknowledgement of multiple foci of skills production, decreeing their overdue certification, as in our case study of the Van Wyk situation. The approach confronts and deconstructs the colonial marginalisation of human capital from outside ‘formal’/official institutions. It is part of the ideological framework of redressing the race and class exclusion mechanisms of artisans and others from the landscape of skills possession. It subscribes therefore to the canon of different ‘ways of knowing’ ( Mosala, 1998). Van Wyk's narrative exemplify the merits of ‘outside-institutions’ learning and enskilment to various levels of complexity. The objective of such legitimation is that certification provides credibility and legitimacy, thereby widening the marketability of apprentices' skills. The social recognition and accorded certification thereof carries uncontested confirmation of expertise.

Obstacles for Women in Leadership Positions: The Case of South Africa

Previous articleNext article No AccessComparative Perspectives Symposium: Challenges to Women's LeadershipObstacles for Women in Leadership Positions: The Case of South AfricaAmanda GouwsAmanda GouwsPolitical Science DepartmentUniversity of Stellenbosch Search for more articles by this author Political Science DepartmentUniversity of StellenboschPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Signs Volume 34, Number 1Autumn 2008 Article DOIhttps://doi.org/10.1086/588486 Views: 516Total views on this site Citations: 20Citations are reported from Crossref © 2008 by The University of Chicago. All rights reserved.PDF download Crossref reports the following articles citing this article:Hlengiwe Portia Dlamini Leadership and gender in Eswatini: Swati politics through the prism of Gelane Simelane Zwane, 1990–2018, Journal of Contemporary African Studies 9 (Feb 2022): 1–15.https://doi.org/10.1080/02589001.2022.2027350Ján Michalko “This Lady, She’s A-List!”: The Empowerment Impact of Womxn Political Elites for Womxn in South African Higher Education, Social Politics: International Studies in Gender, State & Society 28, no.44 (Feb 2020): 1095–1114.https://doi.org/10.1093/sp/jxaa001Ca-Asia A. Lane An Organizational Leadership Response for Women in Leadership: An Analysis of Romans 16:1–16, (Jul 2022): 159–175.https://doi.org/10.1007/978-3-031-04006-1_9Wendy van Eyck, Yolande Steenkamp Leadership Capacities Contributing to the Success of a Multi-Stakeholder Partnership in Eswatini, (Jun 2021): 155–167.https://doi.org/10.1007/978-3-030-70948-8_11Collin Kamalizeni, Mohammad Hoque, Abdullah Kader, Hatikanganwi Mapudzi Towards a Conceptual Framework for Organisationally Effective Female Leadership in Sub-Saharan Africa: The Case of Public Enterprises in Eswatini, Africa Journal of Public Sector Development and Governance 4, no.11 (Jan 2021): 89–110.https://doi.org/10.55390/ajpsdg.2021.4.1.5Efua Prah, Terri Maggott The role of feminisms in building a transformation framework for institutions of higher learning in South Africa, Social Dynamics 16 (Dec 2020): 1–25.https://doi.org/10.1080/02533952.2020.1858541Trang Thi Thu Tran, Huy Van Nguyen Gender preference in higher education leadership: insights from gender distribution and subordinate perceptions and expectations in Vietnam universities, International Journal of Leadership in Education 8 (Apr 2020): 1–22.https://doi.org/10.1080/13603124.2020.1753244Gabi Mkhize, Nwabisa Mgcotyelwa-Ntoni The impact of women’s movements’ activism experiences on gender transformation policies in democratic South Africa, Agenda 33, no.22 (May 2019): 9–21.https://doi.org/10.1080/10130950.2019.1618637Jacqui Poltera Exploring examples of women’s leadership in African contexts, Agenda 33, no.11 (Jul 2019): 3–8.https://doi.org/10.1080/10130950.2019.1602977Jacqui Poltera, Jenny Schreiner Problematising women’s leadership in the African context, Agenda 33, no.11 (Jun 2019): 9–20.https://doi.org/10.1080/10130950.2019.1613057Claude-Hélène Mayer, Sabie Surtee, Jasmin Mahadevan South African women leaders, transformation and diversity conflict intersections, Journal of Organizational Change Management 31, no.44 (Jul 2018): 877–894.https://doi.org/10.1108/JOCM-10-2016-0196Claude-Hélène Mayer, Rian Viviers “Can One Put Faith and Work in the Same Sentence?” Faith Development and Vocation of a Female Leader in the Engineering Profession, Journal of Religion and Health 57, no.33 (May 2017): 821–835.https://doi.org/10.1007/s10943-017-0404-2Claude-Helene Mayer, Louise Tonelli, Rudolf M. Oosthuizen, Sabie Surtee ‘You have to keep your head on your shoulders’: A systems psychodynamic perspective on women leaders, SA Journal of Industrial Psychology 44, no.00 (Mar 2018).https://doi.org/10.4102/sajip.v44i0.1424Claude-Hélène Mayer, Rudolf M. Oosthuizen, Sabie Surtee Emotional intelligence in South African women leaders in higher education, SA Journal of Industrial Psychology 43 (Feb 2017).https://doi.org/10.4102/sajip.v43.1405Claude-Hélène Mayer, Rudolf M. Oosthuizen, Sabie Surtee Emotional intelligence in South African women leaders in higher education, SA Journal of Industrial Psychology 43, no.00 (Feb 2017).https://doi.org/10.4102/sajip.v43i0.1405Lindsay Clowes ‘I act this way because why?’ Prior knowledges, teaching for change, imagining new masculinities, NORMA 10, no.22 (Jul 2015): 149–162.https://doi.org/10.1080/18902138.2015.1050863Claude-Hélène Mayer, Antoni Barnard Balancing the Scales of Gender and Culture in Contemporary South Africa, (Apr 2015): 327–349.https://doi.org/10.1007/978-3-319-14005-6_16Claude-Hélène Mayer, Llewellyn E. Van Zyl Perspectives of female leaders on sense of coherence and mental health in an engineering environment, SA Journal of Industrial Psychology 39, no.22 (Mar 2013).https://doi.org/10.4102/sajip.v39i2.1097Gretchen Bauer Update on the Women's Movement in Botswana: Have Women Stopped Talking?, African Studies Review 54, no.22 (Oct 2013): 23–46.https://doi.org/10.1353/arw.2011.0040Michael M. O. Seipel Gender Empowerment Measure and Policy Choice, Families in Society: The Journal of Contemporary Social Services 91, no.44 (May 2018): 350–355.https://doi.org/10.1606/1044-3894.4036

Freedom from Choice

Freedom from Choice

Les Carnivores du gisement Pliocène final de Saint-Vallier (Drôme, France)

Recent excavations carried out by M. Faure and C. Guérin in the Montrebut palaeontological site (Saint-Vallier, Drôme, France) yield eleven species of Carnivores. They belong to the main Carnivores families (Canidae, Ursidae, Mustelidae, Hyaenidae, Felidae) and confirm most of the former list established by J. Viret (1954). Many new morphometric data have been collected. They give more precision to prior knowledges with which comparisons may be attempted. A complete skull of Chasmaporthetes lunensis (= Euryboas lunensis, Hyaenidae) has been discovered. As the site is better understood, it makes possible to precise the palaeoecology of the species when data is good enough. A spatial approach of the Carnivore's distribution among bones accumulations is possible thanks to a rigorous space record of the fossils. The great number of species but low number of individuals for each of them makes this approach easy.

할선법의 FP-ICA를 이용한 기하학적 변형에 강건한 디지털영상 워터마킹

This paper proposes a digital image watermarking which is robust to geometric distortions using an independent component analysis(ICA) of fixed-point(FP) algorithm based on secant method. The FP algorithm of secant method is applied for better performance in a separation time and rate, and ICA is applied to reject the prior knowledges for original image, key, and watermark such as locations and size, etc. The proposed method embeds the watermark into the spatial domain of original image The proposed watermarking technique has been applied to lena, key, and two watermarks(text and Gaussian noise) respectively. The simulation results show that the proposed method has higher speed and better rate for extracting the original images than the FP algorithm of Newton method. And the proposed method has a watermarking which is robust to geometric distortions such as resizing, rotation, and cropping. Especially, the watermark of images with Gaussian noise has better extraction performance than the watermark with text since Gaussian noise has lower correlation coefficient than the text to the original and key images. The watermarking of ICA doesn`t require the prior knowledge for the original images.

The Metarhetoric of Aristotle, with Some Examples from His On Memory and Recollection

This essay suggests that readers of Aristotle's Rhetoric should take a broader view than is usually applied to understanding the book. Specifically, the reader is asked to explore Aristotle's other works to identify his metarhetoric-that is, Aristotle's notion of the prior knowledges a rhetor needs to have in order to be rhetorical. The essay employs four examples from Aristotle's On Memory and Recollection to demonstrate how ideas from even one of his other books can enhance our comprehension of the Rhetoric. It concludes with a suggested plan for studying Aristotle's metarhetoric.

Sul modo di vincolare la funzione di verosimiglianza quando si è in presenza di informazioni a priori approssimative

The penalty function method is a mathematical approach generally used in non linear programming and is based on the maximization of a (penalty) function obtained combining linearly through some coefficients called penalty parameters an objective function and the constraints expressed in quadratic form. If the objective function satisfies certain conditions about the continuity, the maximization of the penalty function produces a constrained solution only increasing indefinitely the penalty parameters while for finite values assigned to these parameters we obtain a solution placed between the maximum point and the constrained one. From a statistical viewpoint this approach can be used to constraint a likelihood function when we have prior informations on the parameters of approssimative nature. In this case the particular form (quadratic) of the restraints can be seen as a way to catch all the uncertainty included in this type of prior knowledges and the assigned values to the penalty parameters as a way to quantify this uncertainty. Statistically the maximization of the likelihood through the penalty function approach emphasizes two problems: the analysis of the property of the estimator produced by this method and the interpretation of the penalty parameter whose value determines the estimates. In the first case if the usual regularity conditions on the likelihood function are satisfied, the estimator is consistent and asintotically normal whatever is the value of the penalty parameter. In the second case the penalty parameter may be interpreted both as a cost we must pay to depart from the prior informations and as a variance of a stochastic constraint or of a prior distribution. In such a case the penalty function method produces exactly some well known bayesian solutions.