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Abstract: This paper presents numerical solving of the inverse bioheat problem to estimate four skin cancer parameters; diameter, thickness, blood perfusion rate and thermal relaxation time, based on the thermal response on the skin surface obtained by dynamic thermography and numerical skin cancer model, which can greatly enhance dynamic thermography diagnostics. To describe the heat transfer inside biological tissue and thermal behavior during the dynamic thermography process as realistic as possible, the non-Fourier dual-phase-lag bioheat model was used, as well as skin cancer model has been composed of multilayered healthy skin, embedded skin tumor and subcutaneous fat and muscle. Boundary element method has been used to solve a complex non-Fourier bioheat model to simulate dynamic thermography based on the skin cancer model and guessed searched parameters to obtain the thermal response on the skin surface during the cooling and rewarming phase using a cold air jet provocation, which is needed for the solution of the inverse bioheat problem. The inverse problem has been solved by optimization approach using the hybrid Levenberg-Marquardt optimization method, while the measurement data has been generated numerically with known exact tumor parameters and added noise, to evaluate the accuracy and sensitivity of the solution. Inverse problem solution has been tested for two different thermal responses; absolute temperature and temperature difference response, as well as for two different tumor stages; early stage or Clark II and later stage or Clark IV tumor. All important tumor parameters were successfully retrieved, especially the diameter and relaxation time, even for the high level of noise, while the accuracy of obtained parameters is slightly better using absolute temperature response. The results demonstrate the robustness of the method and a promising way for early diagnosis. The findings contribute to improving bioheat modeling in biological tissues, solving inverse bioheat problems and advancing dynamic thermography as a non-invasive tool for early skin cancer diagnosis.
Keywords: numerical modeling, dynamic thermography, inverse problem, non-Fourier bioheat transfer, dual-phase-lag model, boundary element method, Levenberg-Marquardt optimization
Published in DKUM: 09.12.2025; Views: 0; Downloads: 6
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Abstract: A school for the 21st century requires innovative approaches to learning and teaching. The presented research investigates the current state of innovative teaching methods, particularly problem-based learning (PBL), among teachers of the subject Technology and Engineering (TE) in Slovenian lower secondary schools. The main aim of the research was to determine the attitude towards such innovative teaching approaches, how often innovative teaching methods are used, how teachers perceive their importance, and finally, according to the teachers, how they are qualified for this. In the research, an appropriate questionnaire for teachers is developed. Qualitative and quantitative research was conducted using an online survey and statistical data processing. The online survey results showed that teachers positively assess the importance of using PBL, which is perceived as a more challenging method than traditional teaching methods. Despite numerous challenges, teachers express high motivation to improve their teaching practices. Based on the data obtained, it is found that teachers' knowledge is assessed less positively than their competence assessment, which indicates the need for more accurate methods of evaluating knowledge and emphasizes the importance of continuous professional development. The research findings could be important for improving teaching practices and promoting innovations in the educational process. High motivation and readiness of teachers to accept innovative pedagogical approaches can contribute to a better learning environment and the development of a more competent teacher in the future.
Keywords: continuous professional development, innovative teaching methods, problem-based learning, student motivation, teacher competence, technology and engineering
Published in DKUM: 15.09.2025; Views: 0; Downloads: 10
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Abstract: Purpose: The purpose of this study is to preliminarily verify the concept of personalised and collaborative learning and to formatively observe students' knowledge, skills, problem-solving strategies and social dynamics in the classroom. Study design/methodology/approach: The study was conducted with 8th grade students (N=21) using the ClassRoom Analytica (CRA) application as part of a thematic unit on ionic bonds. Students participated in digitally facilitated group problem-solving activities guided by predefined parameters for accessing information. Findings: The use of the CRA application proved highly beneficial in a heterogeneous class as it was responsive to all students and provided the teacher with detailed information about each individual’s role within the class. Originality/value: This study presents CRA as a novel integration of learning analytics and domain-specific visualisations in the science classroom.
Keywords: learning analytics, social interaction, problem-solving
Published in DKUM: 23.07.2025; Views: 0; Downloads: 12
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Abstract: V magistrskem delu preučujemo lastnosti odprtega pakiranja povezav grafa. Za lažje razumevanje obravnavanega pojma najprej predstavimo osnovne pojme in rezultate iz teorije grafov ter opišemo osnovne družine grafov. V drugem delu magistrske naloge opišemo pojma odprto pakiranje povezav in povezavno odprto pakirno število ter ju predstavimo na osnovnih družinah grafov. Tretji del magistrske naloge je namenjen preučevanju mej za povezavno odprto pakirno število poljubnega grafa in identificiranju družin grafov, ki te meje dosežejo. V zadnjem delu magistrske naloge obravnavamo problem odprtega pakiranja povezav grafa kot NP-poln problem za grafe z univerzalnim vozliščem, Eulerjeve dvodelne grafe in ravninske grafe z maksimalno stopnjo največ 4. Opišemo postopek za izračun povezavnega odprtega pakirnega števila dreves in zapišemo, da obstaja algoritem, ki to število poišče v linearnem času.
Keywords: odprto pakiranje povezav, povezavno odprto pakirno število, drevo, časovna zahtevnost algoritma, NP-poln problem
Published in DKUM: 07.07.2025; Views: 0; Downloads: 48
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Abstract: V magistrskem delu je predstavljen pomen izbire ustrezne skladiščne strategije za delo komisionarjev v skladišču gotovih izdelkov. Analizirali smo parametra poti, ki jo opravijo komisionarji pri izpolnjevanju svojih naročil, in celotni čas komisioniranja, ki je potreben za izvedbo naročil. Na realnem primeru smo obravnavali različne metode uskladiščenja izdelkov in dobljene rezultate primerjali z rezultati, pridobljenih z metodo uskladiščenja, ki se trenutno v uporablja v izbranem podjetju. Ugotovili smo, da lahko skladiščna strategija neposredno vpliva na celotno pot in posledično celotni čas komisioniranja, hkrati pa je pomemben faktor tudi obseg naročil (število postavk v posameznem naročilu). Med sabo smo primerjali štiri strategije, ki so pri določanju skladiščnih lokacij posameznim izdelkom upoštevale različne parametre: šifro izdelka, frekventnost odpremljanja, sorodnost med pari izdelkov ali kombinacijo sorodnosti ter frekventnosti. Rezultati prikazani v navedenem magistrskem delu lahko služijo kot osnova za nadaljnje raziskave na področju izbire ustrezne skladiščne strategije v skladišču gotovih izdelkov, ob predpostavki, da poznamo zgodovino izdajanja izdelkov.
Keywords: skladišče gotovih izdelkov, metode uskladiščenja, sorodnost, komisioniranje, problem uskladiščenja izdelkov
Published in DKUM: 13.05.2025; Views: 0; Downloads: 34
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