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Intelligent Train Timetable Generation Technology Based on Monte Carlo Tree Search Algorithm
No full textThis paper presents an innovative approach to train timetable generation using Monte Carlo tree search (MCTS) integrated with a deep reinforcement learning technique. The generation and adjustment of train timetables for high-speed railways represent a complex optimisation problem with numerous rule-based constraints that traditional mathematical methods struggle to solve efficiently. Therefore, the train timetable generation problem is modelled as a discrete spatiotemporal Markov decision process, and a comprehensive MCTS-based algorithm is developed to effectively balance exploration and exploitation through a structured tree search mechanism. The result of the comparative analysis demonstrates that MCTS-based algorithms significantly outperform state-of-the-art reinforcement learning algorithms, including double deep Q-network (DDQN) and proximal policy optimisation (PPO), achieving optimal solutions 6.5 times faster with superior training stability. To validate the scalability and real-world applicability, a large-scale case study involving 120 pairs of trains on the Beijing-Shanghai High-Speed Rail corridor over an 18-hour period successfully resolved all 45,600 initial conflicts. The optimised timetables yield significant operational improvements, including a 16.4% reduction in average delay time, 22.8% improvement in track utilisation efficiency and 9.7% reduction in energy consumption. This research contributes to the advancement of intelligent railway operations optimisation and demonstrates the potential of MCTS-based approaches to transform complex transportation problems
After the boom: What comes next?
Get PDFThe transformer industry is experiencing one of the strongest growth phases in its history. Electrification continues across all regions, digital infrastructure is expanding at scale, and grid operators are under sustained pressure to reinforce networks faster than ever. Demand remains strong, investment is accelerating, and order books reflect confidence across much of the value chain. Many regard this period as a golden age for the industry
Short term results after pulmonary vein isolation with pulsed field ablation in patients with atrial fibrillation
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Decompression Sickness in Divers – Department of Underwater and Hyperbaric Medicine Clinical Hospital Center Experience
No full textCilj: Ronilačka ili kesonska bolest (engl. decompression illness, DCI) zajednički je naziv za dva tipa oboljenja, arterijsku plinsku emboliju i dekompresijsku bolest (engl. decompression sickness, DCS). DCS se ovisno o kliničkoj slici klasificira u dva tipa, tip I i tip II. Cilj ovog rada bio je analizirati učestalost i karakteristike dekompresijske bolesti u ronilaca liječenih u Kliničkom bolničkom centru Rijeka. Ispitanici i metode: Ova retrospektivna studija obuhvatila je sve bolesnike liječene rekompresijskom i hiperbaričnom oksigenoterapijom u Zavodu za podvodnu i hiperbaričnu medicinu Kliničkog bolničkog centra Rijeka u periodu od 1. prosinca 2016. do 31. prosinca 2024. zbog dijagnoze DCS-a. Podatci su prikupljeni iz informatičkog bolničkog sustava (IBIS), i to: dob i spol ispitani¬ka, godišnje doba prijama bolesnika, nacionalnost ronilaca, tip ronjenja, broj i dubina zarona, vrijeme latencije i ishod liječenja. Dobiveni rezultati prikazani su primjenom deskriptivne statistike, dok je razlika u zastupljenosti i povezanosti između analiziranih varijabli analizirana testom χ2 i Spearmanovom korelacijskom analizom. Svi su testovi provedeni na razini statističke značajnosti p < 0,05. Rezultati: U promatranom osmogodišnjem periodu ukupno je u Zavodu za podvodnu i hiperbaričnu medicinu KBC-a Rijeka liječeno 114 ronilaca s dijagnozom DCS-a od čega su većinu činili ronioci muškog spola 98 (86,0 %), u odnosu na 16 (14,0 %) ženskog spola. U dvije trećine ronilaca manifestirala se klinička slika DCS-a tipa 2 (76 ili 66,7 %), a tip 1 bio je prisutan kod 38 (33,3 %) ronilaca. U dobnim skupinama od 31 do 40 i 41 do 50 godina broj oboljelih bio je jednak, a najveći broj oboljelih ronilaca imao je 31 godinu (27,2 %). Najveći broj oboljelih ronilaca bio je tijekom ljetnih mjeseci (63 ili 55,30 %). U većine bolesnika postignuto je potpuno izlječenje (86 ili 75,4 %). Zaključci: Ronioci s DCS-om liječeni u Zavodu za podvodnu i hiperbaričnu medicinu većinom su bili rekreativni ronioci muškog spola s težom kliničkom slikom DCS-a tipa 2, u dobi od 31 do 50 godina, koji su ronili u ljetnim mjesecima te su postignuti izvrsni učinci liječenja sukladni rezultatima svjetskih centara izvrsnosti.Aim: Caisson or diving sickness (decompression illness, DCI) is a common name for two types of diseases, arterial gas embolism and decompression sickness (DCS). According to the severity, DCS is classified into two types, type I and type II. The aim of this study was to determine the frequency and characteristics of DCS among divers treated at the Department of Underwater and Hyperbaric Medicine, University Hospital Center Rijeka. Subjects and methods: All patients admitted to and treated at the Department of Underwater and Hyperbaric Medicine, University Hospital Center Rijeka, between December 1, 2016, and December 31, 2024, who were diagnosed with DCS were included in this retrospective study. Data were collected from the integrated hospital information system and included age, sex, season of admission, nationality, type of dive, number of dives, dive depth, latency period, and treatment outcome. The results were presented using descriptive statistics. Differences in the distribution and associations between variables were analysed using the χ² test and Spearman’s correlation analysis. All tests were conducted at a statistical significance level of p < 0.05. Results: During the evaluated eight-year period, a total of 114 patients were treated for DCS at the Department of Underwater and Hyperbaric Medicine, University Hospital Center Rijeka. The majority were male divers (98; 86.0%), with significantly fewer female divers (16; 14.0%). Two-thirds of the treated patients presented with severe, or type II, DCS (76; 66.7%), while type I DCS was diagnosed in 38 divers (33.3%). The highest and equal number of divers was observed in the 31–40 and 41–50 age groups (31; 27.2% each). A significantly higher number of divers were admitted during the summer months (63; 55.3%). Complete recovery was achieved in the majority of patients (87; 76.3%). Conclusions: Divers treated at the Department of Underwater and Hyperbaric Medicine were predominantly recreational male divers aged 31 to 50 years, most commonly presenting with severe type II DCS during the summer months. Excellent treatment outcomes for DCS were achieved, comparable to those reported by leading international centers
Unrecognized Hypothyroidism As a Cause of Growth Failure – A Case Report
No full textCilj: Prikazati djevojčicu u koje je neprepoznata hipotireoza dovela do zastoja u rastu. Prikaz slučaja: Jedanaestogodišnja djevojčica upućena je na endokrinološku obradu zbog sumnje na Turnerov sindrom. Analizom dostupnih antropometrijskih mjerenja utvrđen je zastoj u rastu tijekom posljednje četiri godine. U navedenom razdoblju djevojčica je narasla 5 cm u visinu. Majka je zamjećivala umor u djevojčice. Kliničkim pregledom utvrđene su grube crte lica i periorbitalni edemi. Tipična fenotipska obilježja Turnerova sindroma nisu zamijećena. Dijagnostičkom je obradom kao uzrok zastoja u rastu potvrđena hipotireoza uslijed autoimunog tireoiditisa. Uvedena je nadomjesna terapija levotiroksinom koja je postupno titrirana do postizanja eutireoze. Šest mjeseci nakon započete terapije zamjećuje se ubrzanje rasta i postupno približavanje ciljnim vrijednostima tjelesne visine prema genetskom potencijalu. Zaključak: Pažljivo praćenje rasta omogućava rano otkrivanje poremećaja rasta i njegova uzroka, kao i primjenu odgovarajućeg liječenja. Nedijagnosticirana i kasno prepoznata hipotireoza može značajno utjecati na rast djece i adolescenata.Aim: To present a case of a girl whose unrecognized hypothyroidism led to growth failure. Case report: An eleven-year-old girl was referred for endocrinological evaluation due to suspicion of Turner syndrome. Upon analysing available anthropometric measurements, a stagnation in growth during the last four years was determined. During this period, the girl grew 5 cm in height. The mother reported noticing the girl's fatigue. Clinical examination revealed coarse facial features and periorbital edema. Typical features of Turner syndrome were not observed. Further medical evaluation confirmed hypothyroidism due to autoimmune thyroiditis as the cause of growth failure. Substitution therapy with levothyroxine was initiated and gradually titrated until euthyroidism was achieved. Six months after the initiation of substitution therapy, growth acceleration and a gradual approach to the target values of body height according to genetic potential was observed. Conclusion: Careful monitoring of growth enables early detection of growth disorders and their underlying causes, as well as administration of appropriate treatment. Undiagnosed and late recognized hypothyroidism can significantly impact the growth of children and adolescents
A Secure Data Aggregation for Clustering Routing Protocols in Heterogenous Wireless Sensor Networks
No full textThe paper presents a broadly elaborated, secure, and energy-efficient data aggregation scheme of the heterogeneous wireless sensor networks (HWSNs). This is motivated by two consistent shortcomings of existing work: (i) clustering-based routing algorithms like LEACH, SEP, and FSEP are inadequate on balancing the energy usage when there is a disparity in the node capabilities, and (ii) most ECC-based security systems create too much computation overhead to extend network lifetime. To satisfy such gaps, the given framework integrates the Spider Monkey Optimization Routing Protocol (SMORP) with a compact cryptographic implementer including the Improved Elliptic Curve Cryptography (IECC) and El Gamal Digital Signature (ELGDS) scheme. SMORP gives maximum consideration to cluster forming and multi hop forwarding and the IECC-ELGDS module that provides all the above data confidentiality, authentication and data integrity at a lower cost of computation. As compared to the previous strategies, the combination of routing optimization and elliptic-curve-based secure aggregation facilitates energy efficiency and high-security assurance in the resource- constrained nodes. MATLAB models show that the offered framework can boost network life up to 27 percent, residual energy up to 32 percent, and get a 96 percent packet-delivery ratio relative to LEACH, SEP, and FSEP. Moreover, the IECC-ELGDS module will need less time in encryption/decryption by 22-35 percent in comparison with ECC-HE, IEKC and ECDH-RSA. These findings support the idea that the SMORP-IECC-ELGDS is a viable and fast architecture to secure aggregation in the real-life HWSN deployment
Data inversion in MCDM problems: nonlinear 1/a and linear ReS inversion
No full textA comprehensive analysis of the procedures for consistent normalization/inversion of benefit and cost attributes for multi-criteria decision making (MCDM) and multivariate classification problems is performed. This study demonstrates that the commonly used 1/a transformation for cost attribute inversion introduces structural inconsistencies in normalized data. Nonlinear data inversion does not have a reasonable interpretation of values and leads to a violation of mutual distances in the original data. The measurement scales of various attributes are not consistent and there is a shift in the domains of normalized values. Elimination of these problems is achieved by using the linear inversion Reverse Sorting algorithm (ReS). The ReS algorithm offers more consistent, linear, and interpretable results for handling cost attributes in MCDM. The ReS algorithm is a linear transformation and preserves the original information about the object: dispositions of attribute values, preserves the relative positions of the domains of different attributes and can be applied to both the original and normalized data sets. The ReS algorithm eliminates all the shortcomings of nonlinear inversion and is recommended for inversion of values when coordinating the optimization goals of a multi-criteria problem, as well as in the weighing methods based on information contained in the decision matrix
CUSTOMER-CENTRICITY IN CRISIS MANAGEMENT: LESSONS FROM LEADING ORGANIZATIONS
No full textCrisis management and customer-centricity are critical strategies for businesses operating in uncertain environments. This paper explores the role of customer-centric approaches during crises by analyzing four case studies from diverse industries – telecommunications, technology, cultural, and tourism sectors. The primary objective of the research is to identify how customer-centric strategies help organisations mitigate adverse effects, foster trust, and enhance long-term customer loyalty during crises. Key findings from the case studies indicate that organisations that adapted swiftly to shifting client needs witnessed increased customer satisfaction and engagement. Additionally, differentiated client support tailored to specific customer segments proved practical for maintaining business continuity. Based on the findings, the paper offers practical recommendations for managers, emphasizing the importance of proactive customer segmentation, transparent and empathetic communication, and investment in innovative solutions during crises. The study calls for future research to quantitatively analyse customer-centric strategies across various industries and crises
Splitting sums of binary polynomials
No full textWe study an analogue of a classical arithmetic problem over the ring of polynomials.
We prove that is the minimal number such that the sums of any two distinct polynomials in a set of polynomials
over cannot all be of the form