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Marine engine cylinder exhaust temperature prediction based on PSO-optimized CNN-LSTM-attention network
Get PDFMarine diesel engines play a critical role in ensuring vessel safety and stable operation. Among their operating parameters, cylinder exhaust gas temperature is a key indicator of an engine’s thermal performance and overall health. Accurate forecasting of this parameter is therefore essential for real-time monitoring and condition-based maintenance in intelligent ship propulsion systems. This study proposes a hybrid CNN-LSTM-Attention model for long-range prediction of marine engine cylinder exhaust temperature. The model utilizes real-world sensor data acquired from shipboard monitoring systems, rather than synthetic or simulated datasets. Experimental results demonstrate the model’s superior performance, achieving a Mean Absolute Error (MAE) of 3.9944, a Mean Absolute Percentage Error (MAPE) of 1.3481 %, and a coefficient of determination (R²) of 0.9805. These metrics indicate high prediction accuracy and minimal deviation from actual values compared to conventional algorithms. To further enhance the model’s predictive capability and generalization performance, Particle Swarm Optimization (PSO) was applied. This automatically fine-tune key hyperparameters, including the optimal parameter settings for learning rate and the number of LSTM units. Results confirm that PSO optimization improves the CNN-LSTM-Attention model’s predictive performance. The predicted temperature curves align better with actual measurements. Specifically, the MAE was reduced by 1.5431, the MSE decreased by 14.3743, and the R² value moved closer to 1. Leveraging PSO’s self-adaptive search capability avoided the need for complex manual hyperparameter tuning. Overall, the findings confirm that the optimized model delivers highly accurate predictions of cylinder exhaust temperature in intelligent marine engines
Determination of the safety exclusion zone for battery-powered ship with consideration of fire accident
Get PDFBattery-powered ships have been developed quickly owing to the international dual carbon strategy and net-zero initiatives. However, the safety of battery-powered ships has attracted much attention because of the high frequency of fire accidents, and maintaining a safety distance between a battery-powered ship and nearby vessels is a proven method to mitigate risks. The large battery capacity poses significant challenges due to intense thermal radiation during fires. Thus, this paper proposes a novel method for determining the safety exclusion zone to mitigate the consequences of collision accidents while considering the thermal runaway of the battery. On basis of a thermal radiation model, the safety distance for avoiding radiation damage is determined by setting the acceptable thermal radiation flux as the threshold level. Afterward, a ship domain model and following theory are used to calculate the longitudinal and lateral safety distances of a battery-powered ship. Finally, a computational fluid dynamics simulation-based case study is carried out to demonstrate the application of the proposed method. This study provides critical insights for policymakers and researchers in advancing maritime safety protocols
Comparison of Timber Measurement Methods and Conversion Factors for Scots Pine
Get PDFAccurate assessment of log and stack volumes is essential for predicting product yields and supporting decision-making in the forest industry. Despite the need to understand stack and log measurement metrics, this remains challenging due to new technological trends, complicated measurement methods, significant variation between regions, species, products, sizes, and age classifications, and prevailing misconceptions about measurement units. The main aim of this study was to compare several currently used log and timber stack volume measurement methods. Additionally, volume conversion factors from gross stack volume to net solid wood volume were calculated. To this end, Scots pine (Pinus sylvestris L.) stands were harvested using a John Deere 1170G harvester. The wood was measured using different methods and technology, including opto-electronic log measurements, manual volumetric timber stack measurements, and photo-optical stack measurements for sawmill, pallet, and other industrial partners. Conversion factors were calculated (dividing the solid wood volume under bark by the gross stacked volume over bark, including air spaces) to convert the gross stack volume into a net or solid wood volume under bark, which is an important unit for roundwood purchasing. The log measurement results showed significant differences between the various wood measurement methods across all assortments. In particular, significant differences were observed between harvester and sawmill measurements. Additionally, a comparison between manual sectional stack measurement and truck load scanning at the sawmill revealed significant differences for the medium-density fibreboard (MDF) timber assortment. Conversion factors ranged from 0.50 to 0.66, with a mean of 0.596, lower for LAS 3 m timber and higher for LAK timber. The results will contribute to a better understanding and general harmonisation of different methods for measuring stacks based on a series of studies of Scots pine assortments
Modelling maritime GHG emission measures impact assessment: A case study for container shipping by system dynamics
Get PDFThe shipping industry is responsible for around 2% of carbon dioxide (CO₂) emissions worldwide. This research explores the interaction of technology change, operational approaches, and policy measures in achieving the target for reducing greenhouse gas (GHG) emissions. A simulation model based on the system dynamics of the maritime transport system has been created in accordance with International Maritime Organization (IMO) policies such as the Energy Efficiency Design Index (EEDI), the Ship Energy Efficiency Management Plan (SEEMP) and the Carbon Intensity Indicator (CII). Suggested actions to reduce the average speed of ships to 15 knots have shown significant reduction of CO₂ emissions in the short term. Further, the complete phase-out of High Fuel Oil (HFO) and the high uptake of Liquefied Natural Gas (LNG), methanol, and ammonia in an aggressive fuel transition scenario significantly lowers emissions by 2050. Market-based instruments such as fuel price mechanisms and carbon taxes are complementary methods that enable emissions reduction by encouraging the transition to cleaner fuels. The report calls for the harmonization of policies for the long-term sustainability of shipping. Future studies can expand the model by incorporating economy-related factors such as carbon prices and emissions trading mechanisms to help the industry achieve its 2050 net-zero target
UTJECAJ ANGAŽMANA NA POSLU, RAVNOTEŽE IZMEĐU POSLOVNOG I PRIVATNOG ŽIVOTA, KAO I UTJECAJ ŽIVOTNOG ZADOVOLJSTVA NA PODUZETNIČKE NAMJERE MEDICINSKIH SESTARA
No full textIn recent years, entrepreneurship in healthcare has emerged as a significant area of scholarly interest. However, limited research has examined how demographic characteristics and specific well-being factors such as life satisfaction, work–life balance, and work engagement jointly influence nurses’ entrepreneurial intentions. This study aims to investigate the effects and interrelationships among these dimensions of well-being and key sociodemographic variables on entrepreneurial intentions among nurses in Kosovo. A cross-sectional research design was employed, and data were collected through self-administered questionnaires from 415 nurses working in primary, secondary and tertiary care. The data were analysed using SmartPLS and STATA to assess both the measurement and structural models. The findings reveal that sociodemographic factors significantly shape nurses’ entrepreneurial intentions. Male nurses report higher entrepreneurial intentions than female nurses, and nurses with a bachelor’s or master’s degree exhibit stronger entrepreneurial intentions than those with only secondary education. Higher household income is negatively associated with entrepreneurial intention, suggesting that nurses with lower income are more inclined to be entrepreneurs. Age, years of experience, and level of care do not emerge as significant predictors in the fully adjusted model. Moreover, work–life balance, life satisfaction, and work engagement all show significant positive relationships with entrepreneurial intention. The results suggest that higher life satisfaction, better work–life balance and stronger work engagement enhance nurses’ entrepreneurial intentions, over and above demographic characteristics. Additionally, being male, having a higher level of education and reporting lower income are associated with greater entrepreneurial inclination. These findings underscore the importance of considering both workforce well-being and sociodemographic profiles as strategic levers to foster entrepreneurship within the healthcare sector.Posljednjih je godina poduzetništvo u zdravstvenom sektoru postalo značajno područje znanstvenog interesa. Međutim, malo je istraživanja ispitivalo kako demografske karakteristike i specifični čimbenici dobrobiti, poput životnog zadovoljstva, ravnoteže između poslovnog i privatnog života te radnog angažmana, zajednički utječu na poduzetničke namjere medicinskih sestara. Cilj je ove studije istražiti učinke i međusobne odnose između ovih dimenzija dobrobiti te ključnih sociodemografskih varijabli na poduzetničke namjere medicinskih sestara na Kosovu. Korišten je presječni dizajn istraživanja, a podaci su prikupljeni s pomoću samostalno ispunjavanih upitnika za 415 medicinskih sestara koje rade u primarnoj, sekundarnoj i tercijarnoj zdravstvenoj zaštiti. Podaci su analizirani s pomoću SmartPLS-a i STATA-e za procjenu mjernih i strukturnih modela. Nalazi otkrivaju da sociodemografski čimbenici značajno oblikuju poduzetničke namjere medicinskih sestara. Medicinski tehničari pokazuju veće poduzetničke namjere od ženskih medicinskih sestara, a medicinske sestre s prvostupničkom ili magistarskom diplomom pokazuju jače poduzetničke namjere od onih sa samo srednjoškolskim obrazovanjem. Viši prihod kućanstva negativno je povezan s poduzetničkom namjerom, što sugerira da su medicinske sestre s nižim prihodima sklonije poduzetništvu. Dob, godine iskustva i razina skrbi ne pojavljuju se kao značajni prediktori u potpuno prilagođenom modelu. Štoviše, ravnoteža između poslovnog i privatnog života, zadovoljstvo životom i angažman na poslu pokazuju značajne pozitivne odnose s poduzetničkom namjerom. Rezultati sugeriraju da veće zadovoljstvo životom, bolja ravnoteža između poslovnog i privatnog života te jači angažman na poslu pojačavaju poduzetničke namjere medicinskih sestara, uz demografske karakteristike. Osim toga, muški spol, viša razina obrazovanja i prijavljivanje nižih prihoda povezani su s većom sklonošću poduzetništvu. Ovi nalazi naglašavaju važnost razmatranja dobrobiti radne snage i sociodemografskih profila kao strateških poluga za poticanje poduzetništva unutar zdravstvenog sektora
STUDIJA SLUČAJA O OPTIMIZACIJI RAZMAKA DISK REZAČA NA TEMELJU GRANIČNE VRIJEDNOSTI VERTIKALNE SILE PRI REZANJU CRVENOGA GRANITA IZ COLORADA KORIŠTENJEM SOFTVERA LS-DYNA
No full textThis research initially employed a Lagrangian algorithm to simulate two uniaxial compressive and Brazilian tests for validating the calibrated structural model, with errors recorded at 2.5% and 13%, respectively. Subsequently, using meshfree Galerkin particles and the Johnson-Holmquist concrete material model, simulations of linear shear cutting of Colorado red granite were performed, achieving errors of 10% for vertical force and 13% for rotational force compared to the experimental results from Gertsch and colleagues. These results indicate that the modelling possesses sufficient validity. Instead of determining the optimal spacing through specific energy, a method based on 80% of the maximum vertical force tolerable by the cutting disc is proposed, which aligns with the specific energy method that has significant rigidity and drawbacks, demonstrating that this alternative approach is considerably advantageous and simpler. The optimal spacing calculated for 17-inch discs is determined to be 76 mm.U ovome istraživanju najprije je primijenjen Lagrangeov algoritam za simulaciju dvaju ispitivanja: jednoosno tlačnog ispitivanja i brazilskoga testa radi validacije umjerenoga strukturnog modela, pri čemu su zabilježene pogreške od 2,5 % i 13 %. Nakon toga korištenjem metode Galerkinovih čestica bez mreže te Johnson-Holmquistova modela betona provedene su simulacije linearne smične obrade crvenoga granita iz Colorada. Dobivene su pogreške od 10 % za vertikalnu silu i 13 % za rotacijsku silu u usporedbi s eksperimentalnim rezultatima koje su objavili Gertsch i suradnici. Ovi rezultati upućuju na dovoljnu valjanost modeliranja. Umjesto određivanja optimalnoga razmaka na temelju specifične energije predložena je metoda zasnovana na 80 % maksimalne vertikalne sile koju disk rezač može podnijeti. Ta se metoda pokazala usklađenom s pristupom temeljenim na specifičnoj energiji koji ima izraženu rigidnost i nedostatke, pri čemu se novi pristup pokazuje znatno povoljnijim i jednostavnijim. Određen je optimalni razmak od 76 mm za disk rezače promjera 17 inča
Editorial message
Get PDFThe January edition of Transformer Magazine opens the year with reflection, realism, and a forward-looking perspective. After a period of exceptional growth and sustained pressure across the industry, this issue focuses on what comes next: how the transformer sector adapts its strategies, technologies, and thinking to remain resilient in a more complex and demanding environment
Bridging the translational gap: immune-metabolic dysregulation in age-related metabolic and vascular diseases in real-world populations
Get PDFOperational performance of container terminals in the North Adriatic ports
Get PDFThe significant increase in the number of calls by larger container ships also has an impact on productivity and therefore on the performance of container ports in the northern Adriatic. The productivity of a container terminal depends heavily on the processes at the berth, yard and in the gate area. In our analysis, we have therefore analysed the current capacity and operational performance of each terminal subsystem using KPIs (Key Performance Indicator) and outlined the investment plans required to enable the ports of Koper, Trieste and Rijeka to accommodate larger container vessels. These container ports handle less than 2.4 million TEU per year (2024), which is below what they could achieve given the backhaul market. Analyses have shown that improving the productivity of loading and unloading in the berth area is an effective measure to increase container traffic in the ports of the North Adriatic and improve their market share. Investments in the procurement of new quay cranes, increasing the draught at the berths and expanding the berths play a key role in this. Only with timely measures will the ports of the northern Adriatic be able to compete with their northern European rivals
