{"id":{"repo_id":"greece","oai_identifier":"oai:10442/1429"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/1429","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"ΕΠΙΔΡΑΣΗ ΑΝΟΜΟΙΟΜΟΡΦΗΣ ΑΝΑΔΡΑΣΗΣ ΣΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ ΑΝΙΧΝΕΥΤΗ","abstract":"A Λ-D MODEL OF SPACE DEPENDENT FEEDBACK IN BWR'S IS PRESENTED. EQUATIONS ARE SOLVED NUMERICALLY WITH THE METHOD OF FINITE DIFFERENCE APPROXIMATION TO DERIVATIVES. IT WAS FOUND THAT FEEDBACK WILL, IN GENERAL, REDUCE THE DETECTOR FIELD OF VIEW AT LOW FREQUENCIES, IN AGREEMENT WITH PREVIOUS INVESTIGATIONS, BUT THE COUPLING OF DIFFERENT FEEDBACK MECHANISMS MAY REVERSE THIS EFFECT. THE MODEL IS THEN MODIFIED TO A FORM AMENABLE TOP ANALYTICAL SOLUTION AND IT IS CONCLUDED THATSPACE DEPENDENT FEEDBACK MAY INCREASE, DECREASE OR EVEN DISPLACE THE DETECTOR FIELD OF VIEW. LAST BOILING AND PRESSURE FEEDBACK EFFECTS ON NEUTRON NOISE ARE INVESTIGATED. IT IS CONCLUDED THAT THE STRUCTURE OF NEUTRON NOISE COHERENCES ATLOW FREQUENCIES CAN BE EXPLAINED BY EITHER PRESSURE OR/AND BOILING FEEDBACK.","abstract_html":"A Λ-D MODEL OF SPACE DEPENDENT FEEDBACK IN BWR'S IS PRESENTED. EQUATIONS ARE SOLVED NUMERICALLY WITH THE METHOD OF FINITE DIFFERENCE APPROXIMATION TO DERIVATIVES. IT WAS FOUND THAT FEEDBACK WILL, IN GENERAL, REDUCE THE DETECTOR FIELD OF VIEW AT LOW FREQUENCIES, IN AGREEMENT WITH PREVIOUS INVESTIGATIONS, BUT THE COUPLING OF DIFFERENT FEEDBACK MECHANISMS MAY REVERSE THIS EFFECT. THE MODEL IS THEN MODIFIED TO A FORM AMENABLE TOP ANALYTICAL SOLUTION AND IT IS CONCLUDED THATSPACE DEPENDENT FEEDBACK MAY INCREASE, DECREASE OR EVEN DISPLACE THE DETECTOR FIELD OF VIEW. LAST BOILING AND PRESSURE FEEDBACK EFFECTS ON NEUTRON NOISE ARE INVESTIGATED. IT IS CONCLUDED THAT THE STRUCTURE OF NEUTRON NOISE COHERENCES ATLOW FREQUENCIES CAN BE EXPLAINED BY EITHER PRESSURE OR/AND BOILING FEEDBACK.","abstract_has_math":false,"creators":["Χατζηαθανασίου, Βασίλειος","Chatziathanasiou, Vasileios"],"institution":"Aristotle University Of Thessaloniki (AUTH)","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1989,"date_issued":"1989","date_published":"1989","updated_at":"2026-07-24T02:24:56Z","subjects":["Ανάδραση","ΑΝΤΙΔΡΑΣΤΗΡΑΣ ΖΕΟΝΤΟΣ ΥΔΑΤΟΣ","Βρασμός","ΕΞΑΡΤΗΣΗ ΑΠΟ ΧΩΡΑ","ΘΟΡΥΒΟΣ ΑΝΤΙΔΡΑΣΤΗΡΑ","ΝΕΤΡΟΝΙΚΟΣ ΘΟΡΥΒΟΣ","Πίεση","Boiling","BWD","Feedback","NEUTRON NOISE","Pressure","REACTOR NOISE","SPACE DEPENDENCE","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1429"],"render_values":[{"text":"10.12681/eadd/1429","href":"https://doi.org/10.12681/eadd/1429","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/1429","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Χατζηαθανασίου, Βασίλειος","Chatziathanasiou, Vasileios"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1989"]},{"key":"dc:publisher","label":"Institution","values":["Aristotle University Of Thessaloniki (AUTH)","Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ)"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ανάδραση","ΑΝΤΙΔΡΑΣΤΗΡΑΣ ΖΕΟΝΤΟΣ ΥΔΑΤΟΣ","Βρασμός","ΕΞΑΡΤΗΣΗ ΑΠΟ ΧΩΡΑ","ΘΟΡΥΒΟΣ ΑΝΤΙΔΡΑΣΤΗΡΑ","ΝΕΤΡΟΝΙΚΟΣ ΘΟΡΥΒΟΣ","Πίεση","Boiling","BWD","Feedback","NEUTRON NOISE","Pressure","REACTOR NOISE","SPACE DEPENDENCE","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1429","http://hdl.handle.net/10442/hedi/1429"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A Λ-D MODEL OF SPACE DEPENDENT FEEDBACK IN BWR'S IS PRESENTED. EQUATIONS ARE SOLVED NUMERICALLY WITH THE METHOD OF FINITE DIFFERENCE APPROXIMATION TO DERIVATIVES. IT WAS FOUND THAT FEEDBACK WILL, IN GENERAL, REDUCE THE DETECTOR FIELD OF VIEW AT LOW FREQUENCIES, IN AGREEMENT WITH PREVIOUS INVESTIGATIONS, BUT THE COUPLING OF DIFFERENT FEEDBACK MECHANISMS MAY REVERSE THIS EFFECT. THE MODEL IS THEN MODIFIED TO A FORM AMENABLE TOP ANALYTICAL SOLUTION AND IT IS CONCLUDED THATSPACE DEPENDENT FEEDBACK MAY INCREASE, DECREASE OR EVEN DISPLACE THE DETECTOR FIELD OF VIEW. LAST BOILING AND PRESSURE FEEDBACK EFFECTS ON NEUTRON NOISE ARE INVESTIGATED. IT IS CONCLUDED THAT THE STRUCTURE OF NEUTRON NOISE COHERENCES ATLOW FREQUENCIES CAN BE EXPLAINED BY EITHER PRESSURE OR/AND BOILING FEEDBACK.","ΠΑΡΟΥΣΙΑΖΕΤΑΙ ΜΟΝΟΔΙΑΣΤΑΤΟ ΜΟΝΤΕΛΛΟ ΑΝΑΔΡΑΣΗΣ ΠΟΥ ΕΞΑΡΤΑΤΑΙ ΑΠΟ ΤΟ ΧΩΡΟ, ΣΕ ΑΝΤΙΔΡΑΣΤΗΡΑ BWR. ΟΙ ΣΧΕΤΙΚΕΣ ΕΞΙΣΩΣΕΙΣ ΛΥΝΟΝΤΑΙ ΑΡΙΘΜΗΤΙΚΑ ΜΕ ΤΗ ΜΕΘΟΔΟ ΤΩΝ ΠΕΠΕΡΑΣΜΕΝΩΝ ΔΙΑΦΟΡΩΝ. ΒΡΕΘΗΚΕ ΟΤΙ ΓΕΝΙΚΑ Η ΑΝΑΔΡΑΣΗ ΜΕΙΩΝΕΙ ΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ ΤΟΥ ΑΝΙΧΝΕΥΤΗ ΣΤΙΣ ΧΑΜΗΛΕΣ ΣΥΧΝΟΤΗΤΕΣ, ΣΥΜΠΕΡΑΣΜΑ ΗΔΗ ΓΝΩΣΤΟ ΑΠΟ ΠΡΟΗΓΟΥΜΕΝΕΣ ΕΡΕΥΝΕΣ,Η ΣΥΖΕΥΞΗ ΟΜΩΣ ΔΙΑΦΟΡΩΝ ΜΗΧΑΝΙΣΜΩΝ ΑΝΑΔΡΑΣΗΣ ΜΠΟΡΕΙ Ν' ΑΝΑΙΡΕΣΕΙ ΤΟ ΦΑΙΝΟΜΕΝΟ ΑΥΤΟ. ΣΤΗ ΣΥΝΕΧΕΙΑ ΤΟ ΜΟΝΤΕΛΛΟ ΤΡΟΠΟΠΟΙΕΙΤΑΙ ΕΤΣΙ ΩΣΤΕ ΝΑ ΥΠΑΡΧΕΙ ΑΝΑΛΥΤΙΚΗ ΛΥΣΗ. ΠΡΟΚΥΠΤΕΙ ΟΤΙ Η ΑΠΟ ΤΟ ΧΩΡΟ ΕΞΑΡΤΩΜΕΝΗ ΑΝΑΔΡΑΣΗ ΜΠΟΡΕΙ Ν' ΑΥΞΗΣΕΙ, ΝΑ ΜΕΙΩΣΕΙ 'Η ΚΑΙ ΝΑ ΜΕΤΑΤΟΠΙΣΕΙ ΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ. ΣΤΟ ΤΕΛΕΥΤΑΙΟ ΣΤΑΔΙΟ ΕΙΣΑΓΕΤΑΙ ΚΑΙ Η ΕΠΙΔΡΑΣΗ ΤΗΣ ΑΝΑΔΡΑΣΗΣ ΑΠΟ ΤΟ ΣΥΣΤΗΜΑ ΕΛΕΓΧΟΥ ΤΗΣ ΠΙΕΣΗΣ ΚΑΙ ΓΙΝΕΤΑΙ ΚΑΙ Η ΣΥΓΚΡΙΣΗ ΤΗΣ ΕΠΙΔΡΑΣΗΣ ΤΗΣ Μ' ΑΥΤΗΝ ΤΗΣ ΑΝΑΔΡΑΣΗΣ ΛΟΓΩ ΒΡΑΣΜΟΥ. ΣΥΜΠΕΡΑΙΝΕΤΑΙ ΟΤΙ Η ΜΟΡΦΗ ΤΩΝ ΣΥΝΑΡΤΗΣΕΩΝ ΣΥΝΕΠΕΙΑΣ ΝΕΤΡΟΝΙΚΟΥ ΘΟΡΥΒΟΥ ΣΤΙΣ ΧΑΜΗΛΕΣ ΣΥΧΝΟΤΗΤΕΣ ΜΠΟΡΕΙ ΝΑ ΕΞΗΓΗΘΕΙ ΕΙΤΕ ΑΠΟ ΤΗΝ ΑΝΑΔΡΑΣΗ ΠΙΕΣΗΣ 'Η/ΚΑΙ ΑΠΟ ΤΗΝ ΑΝΑΔΡΑΣΗ ΒΡΑΣΜΟΥ."]},{"key":"dc:title","label":"Title","values":["ΕΠΙΔΡΑΣΗ ΑΝΟΜΟΙΟΜΟΡΦΗΣ ΑΝΑΔΡΑΣΗΣ ΣΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ ΑΝΙΧΝΕΥΤΗ","NON-UNIFORM FEEDBACK EFFECTS ON THE DETECTOR FIELD OF VIEW"]}]}],"canonical_facts":{"dc:creator":["Χατζηαθανασίου, Βασίλειος","Chatziathanasiou, Vasileios"],"dc:date":["1989"],"dc:description":["A Λ-D MODEL OF SPACE DEPENDENT FEEDBACK IN BWR'S IS PRESENTED. EQUATIONS ARE SOLVED NUMERICALLY WITH THE METHOD OF FINITE DIFFERENCE APPROXIMATION TO DERIVATIVES. IT WAS FOUND THAT FEEDBACK WILL, IN GENERAL, REDUCE THE DETECTOR FIELD OF VIEW AT LOW FREQUENCIES, IN AGREEMENT WITH PREVIOUS INVESTIGATIONS, BUT THE COUPLING OF DIFFERENT FEEDBACK MECHANISMS MAY REVERSE THIS EFFECT. THE MODEL IS THEN MODIFIED TO A FORM AMENABLE TOP ANALYTICAL SOLUTION AND IT IS CONCLUDED THATSPACE DEPENDENT FEEDBACK MAY INCREASE, DECREASE OR EVEN DISPLACE THE DETECTOR FIELD OF VIEW. LAST BOILING AND PRESSURE FEEDBACK EFFECTS ON NEUTRON NOISE ARE INVESTIGATED. IT IS CONCLUDED THAT THE STRUCTURE OF NEUTRON NOISE COHERENCES ATLOW FREQUENCIES CAN BE EXPLAINED BY EITHER PRESSURE OR/AND BOILING FEEDBACK.","ΠΑΡΟΥΣΙΑΖΕΤΑΙ ΜΟΝΟΔΙΑΣΤΑΤΟ ΜΟΝΤΕΛΛΟ ΑΝΑΔΡΑΣΗΣ ΠΟΥ ΕΞΑΡΤΑΤΑΙ ΑΠΟ ΤΟ ΧΩΡΟ, ΣΕ ΑΝΤΙΔΡΑΣΤΗΡΑ BWR. ΟΙ ΣΧΕΤΙΚΕΣ ΕΞΙΣΩΣΕΙΣ ΛΥΝΟΝΤΑΙ ΑΡΙΘΜΗΤΙΚΑ ΜΕ ΤΗ ΜΕΘΟΔΟ ΤΩΝ ΠΕΠΕΡΑΣΜΕΝΩΝ ΔΙΑΦΟΡΩΝ. ΒΡΕΘΗΚΕ ΟΤΙ ΓΕΝΙΚΑ Η ΑΝΑΔΡΑΣΗ ΜΕΙΩΝΕΙ ΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ ΤΟΥ ΑΝΙΧΝΕΥΤΗ ΣΤΙΣ ΧΑΜΗΛΕΣ ΣΥΧΝΟΤΗΤΕΣ, ΣΥΜΠΕΡΑΣΜΑ ΗΔΗ ΓΝΩΣΤΟ ΑΠΟ ΠΡΟΗΓΟΥΜΕΝΕΣ ΕΡΕΥΝΕΣ,Η ΣΥΖΕΥΞΗ ΟΜΩΣ ΔΙΑΦΟΡΩΝ ΜΗΧΑΝΙΣΜΩΝ ΑΝΑΔΡΑΣΗΣ ΜΠΟΡΕΙ Ν' ΑΝΑΙΡΕΣΕΙ ΤΟ ΦΑΙΝΟΜΕΝΟ ΑΥΤΟ. ΣΤΗ ΣΥΝΕΧΕΙΑ ΤΟ ΜΟΝΤΕΛΛΟ ΤΡΟΠΟΠΟΙΕΙΤΑΙ ΕΤΣΙ ΩΣΤΕ ΝΑ ΥΠΑΡΧΕΙ ΑΝΑΛΥΤΙΚΗ ΛΥΣΗ. ΠΡΟΚΥΠΤΕΙ ΟΤΙ Η ΑΠΟ ΤΟ ΧΩΡΟ ΕΞΑΡΤΩΜΕΝΗ ΑΝΑΔΡΑΣΗ ΜΠΟΡΕΙ Ν' ΑΥΞΗΣΕΙ, ΝΑ ΜΕΙΩΣΕΙ 'Η ΚΑΙ ΝΑ ΜΕΤΑΤΟΠΙΣΕΙ ΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ. ΣΤΟ ΤΕΛΕΥΤΑΙΟ ΣΤΑΔΙΟ ΕΙΣΑΓΕΤΑΙ ΚΑΙ Η ΕΠΙΔΡΑΣΗ ΤΗΣ ΑΝΑΔΡΑΣΗΣ ΑΠΟ ΤΟ ΣΥΣΤΗΜΑ ΕΛΕΓΧΟΥ ΤΗΣ ΠΙΕΣΗΣ ΚΑΙ ΓΙΝΕΤΑΙ ΚΑΙ Η ΣΥΓΚΡΙΣΗ ΤΗΣ ΕΠΙΔΡΑΣΗΣ ΤΗΣ Μ' ΑΥΤΗΝ ΤΗΣ ΑΝΑΔΡΑΣΗΣ ΛΟΓΩ ΒΡΑΣΜΟΥ. ΣΥΜΠΕΡΑΙΝΕΤΑΙ ΟΤΙ Η ΜΟΡΦΗ ΤΩΝ ΣΥΝΑΡΤΗΣΕΩΝ ΣΥΝΕΠΕΙΑΣ ΝΕΤΡΟΝΙΚΟΥ ΘΟΡΥΒΟΥ ΣΤΙΣ ΧΑΜΗΛΕΣ ΣΥΧΝΟΤΗΤΕΣ ΜΠΟΡΕΙ ΝΑ ΕΞΗΓΗΘΕΙ ΕΙΤΕ ΑΠΟ ΤΗΝ ΑΝΑΔΡΑΣΗ ΠΙΕΣΗΣ 'Η/ΚΑΙ ΑΠΟ ΤΗΝ ΑΝΑΔΡΑΣΗ ΒΡΑΣΜΟΥ."],"dc:identifier":["10.12681/eadd/1429","http://hdl.handle.net/10442/hedi/1429"],"dc:language":["gre"],"dc:publisher":["Aristotle University Of Thessaloniki (AUTH)","Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ)"],"dc:subject":["Ανάδραση","ΑΝΤΙΔΡΑΣΤΗΡΑΣ ΖΕΟΝΤΟΣ ΥΔΑΤΟΣ","Βρασμός","ΕΞΑΡΤΗΣΗ ΑΠΟ ΧΩΡΑ","ΘΟΡΥΒΟΣ ΑΝΤΙΔΡΑΣΤΗΡΑ","ΝΕΤΡΟΝΙΚΟΣ ΘΟΡΥΒΟΣ","Πίεση","Boiling","BWD","Feedback","NEUTRON NOISE","Pressure","REACTOR NOISE","SPACE DEPENDENCE","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering"],"dc:title":["ΕΠΙΔΡΑΣΗ ΑΝΟΜΟΙΟΜΟΡΦΗΣ ΑΝΑΔΡΑΣΗΣ ΣΤΟ ΟΠΤΙΚΟ ΠΕΔΙΟ ΑΝΙΧΝΕΥΤΗ","NON-UNIFORM FEEDBACK EFFECTS ON THE DETECTOR FIELD OF VIEW"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:24:56Z"}