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2. Relaxations and exact solutions to Quantum Max Cut via the algebraic structure of swap operatorsAdam Bene Watts, Anirban Chowdhury, Aidan Epperly, J. William Helton, Igor Klep, 2024, original scientific article Abstract: The Quantum Max Cut (QMC) problem has emerged as a test-problem for designing approximation algorithms for local Hamiltonian problems. In this paper we attack this problem using the algebraic structure of QMC, in particular the relationship between the quantum max cut Hamiltonian and the representation theory of the symmetric group. The first major contribution of this paper is an extension of non-commutative Sum of Squares (ncSoS) optimization techniques to give a new hierarchy of relaxations to Quantum Max Cut. The hierarchy we present is based on optimizations over polynomials in the qubit swap operators. This is in contrast to the "standard" quantum Lasserre Hierarchy, which is based on polynomials expressed in terms of the Pauli matrices. To prove correctness of this hierarchy, we exploit a finite presentation of the algebra generated by the qubit swap operators. This presentation allows for the use of computer algebraic techniques to manipulate and simplify polynomials written in terms of the swap operators, and may be of independent interest. Surprisingly, we find that level-2 of this new hierarchy is numerically exact (up to tolerance $10^{-7}$) on all QMC instances with uniform edge weights on graphs with at most 8 vertices. The second major contribution of this paper is a polynomial-time algorithm that computes (in exact arithmetic) the maximum eigenvalue of the QMC Hamiltonian for certain graphs, including graphs that can be "decomposed" as a signed combination of cliques. A special case of the latter are complete bipartite graphs with uniform edge-weights, for which exact solutions are known from the work of Lieb and Mattis. Our methods, which use representation theory of the symmetric group, can be seen as a generalization of the Lieb-Mattis result.
Keywords: Quantum Max Cut, swap operators, noncommutative polynomials, symmetric group, Gröbner bases
Published in DiRROS: 04.06.2024; Views: 52; Downloads: 32
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4. Primary pulmonary choricarcinomaŽiga Snoj, Igor Kocijančič, Erik Škof, 2017, review article Abstract: The aim of the study was to establish whether there are different clinical entities of primary pulmonary choriocarcinoma (PPC) that deserve different diagnostic approach and the most optimal treatment. Patients and methods. A systematic review with PubMed search was conducted to identify studies that reported cases of PPC. The eligibility criteria were histological diagnosis of pulmonary choriocarcinoma and thorough examination of the reproductive organs to exclude potential primary choriocarcinoma in the gonads. Furthermore, to illustrate the review we additionally present a patient referred at our institution. Results. 55 cases (17 men) were included in the review with a median age of 34 years. Women with the history of gestational event showed better survival outcome than women without the history of gestational event. Patients treated with combined modality treatment (surgery and chemotherapy) survived longer than the patients without combined modality treatment. Furthermore, multivariate analysis of prognostic factors showed that the combined modality treatment had independent prognostic significance. Size of the tumour showed significant prognostic influence in univariate and multivariate analysis. Conclusions. PPC is an extreme rarity with variable clinical characteristics and outcome. It is important to capture and treat patients in the early stages of the disease. Women with the history of gestational event may show better survival, therefore genetic examination could help us to predict patient%s prognosis. Surgery followed by adjuvant chemotherapy appears to represent the best treatment for PPC.
Keywords: choriocarcinoma, gestational event, pulmonary tumor, primary horiokarcinom
Published in DiRROS: 10.05.2024; Views: 122; Downloads: 50
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7. NutriGreen image dataset : a collection of annotated nutrition, organic, and vegan food productsJan Drole, Igor Pravst, Tome Eftimov, Barbara Koroušić-Seljak, 2024, original scientific article Abstract: In this research, we introduce the NutriGreen dataset, which is a collection of images representing branded food products aimed for training segmentation models for detecting various labels on food packaging. Each image in the dataset comes with three distinct labels: one indicating its nutritional quality using the Nutri-Score, another denoting whether it is vegan or vegetarian origin with the V-label, and a third displaying the EU organic certification (BIO) logo.
Published in DiRROS: 23.04.2024; Views: 185; Downloads: 57
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8. Segmentation of hepatic vessels from MRI images for planning of electroporation-based treatments in the liverMarija Marčan, Denis Pavliha, Maja Marolt-Mušič, Igor Fučkan, Ratko Magjarević, Damijan Miklavčič, 2014, original scientific article Keywords: electrochemotherapy, non-thermal irreversible electroporation, treatment planning, hepatic vessel segmentation, non-invasive tumor treatments, MRI of liver
Published in DiRROS: 16.04.2024; Views: 171; Downloads: 73
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9. Depth of SCUBA diving affects cardiac autonomic nervous systemMarina Vulić, Branislav Milovanovic, Ante Obad, Duška Glavaš, Igor Glavičič, Damir Zubac, Maja Valic, Zoran Valić, 2024, review article Abstract: The present study investigated the influence of SCUBA dives with compressed air at depths of 10 and 20 m on ECG-derived HRV parameters in apparently healthy individuals. We hypothesized that cardiac sympathetic activity (measured by HRV parameters) adapts proportionally to diving depth, and that both time- and frequency-domain parameters are sensitive enough to track changes in cardiac ANS function during diving activities and subsequently during the recovery period. Eleven healthy middle-aged recreational divers (nine men and two women, age 43 ± 8, all nonsmokers) volunteered to participate in the present study. The participants (all open-circuit divers) were equipped with dry suits and ECG Holter devices and were later randomly assigned to dive pairs and depths (10 m vs. 20 m), and each participant served as his or her own control. No interaction effects (diving depth x time epoch) were found for the most commonly used HRV markers. More precisely, in response to two different diving protocols, a significant post hoc effect of time was observed for HR and SDNN, as these parameters transiently decreased during the dives and returned to baseline after ascent (p < 0.001). The ULF, VLF (p < 0.003), TP, and LF parameters decreased significantly during the dives, while HF significantly increased (p < 0.003). SCUBA diving apparently challenges the cardiac ANS, even in healthy individuals. The observed changes reveal possible underwater methods of influencing the parasympathetic activity of the heart depending on the depth of the dive. These results identify autonomic nervous system markers to track the cardiovascular risk related to diving and point to the possibility of tracking cardiovascular system benefits during underwater activities in selected patients
Keywords: autonomic nervous system, diving, parasympathicus, cardiovascular risk
Published in DiRROS: 09.04.2024; Views: 190; Downloads: 84
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