Pyeongtaek University

Jerusalem artichoke (JA) (Helianthus tuberosus), a perennial plant of the Asteraceae family, is well known for its high inulin content and diverse bioactive compounds, including flavonoids, phenolic acids, sesquiterpenes, and amino acids. Extracts derived from different parts of JA, such as tubers, leaves, and flowers, have demonstrated a wide range of biological activities, including antioxidant, anti-inflammatory, antihyperglycemic, antihypertensive, and antifungal effects. These properties highlight JA's potential in the prevention and management of chronic diseases such as diabetes, cardiovascular disorders, obesity, and colorectal cancer. Recent studies also suggest that JA benefits skin health through anti-aging and barrier-protective mechanisms and enhances immune function by modulating the intestinal microbiota. Owing to its multifunctional physiological activities, JA is being explored as a valuable raw material for food, nutraceutical, cosmetic, and pharmaceutical applications. However, most existing research has focused primarily on inulin, while comprehensive studies on other bioactive constituents and their clinical validation remain limited. This paper aims to provide a comprehensive overview of the bioactive compounds present in JA, elucidate their health-promoting functions, discuss their pharmacokinetics, and outline future perspectives on their potential as functional ingredients and biohealth materials.

High-rise buildings present substantial challenges for firefighting and rescue operations owing to their considerable height. The stack effect, which becomes more pronounced with increasing building height, accelerates smoke propagation and significantly increases the likelihood of casualties. This study identifies and analyzes the risks associated with fire incidents in high-rise residential buildings. A 49-story building was selected as the reference model, and population density was applied to estimate occupant numbers for the risk assessment. For the damage scenario, one disaster-vulnerable individual per household was assumed. The simulation results revealed that firefighters and vulnerable occupants were exposed to smoke within 541 s. The findings of this study indicate that the stack effect, amplified by building height, exacerbates fire and smoke spread, thereby increasing firefighting risks and potential casualties. These results highlight fire incidents in high-rise structures as a critical category of urban disaster. Furthermore, the study underscores the limitations of existing firefighting facilities in addressing such scenarios and emphasizes the urgent need for new paradigms in firefighting strategies and smoke control technologies to mitigate the risks associated with the stack effect.

This paper presents an experimental campaign on a complete liquid hydrogen (LH 2 ) propulsion system for small uncrewed aerial vehicles. The first part investigates the boil-off performance of five 12 L (0.85 kg) LH 2 reservoirs with different internal designs. Results show average evaporation rates of 17–37 g/h and total evaporation times of 23–50 h, corresponding to endurance of up to 50 h depending on fabrication technique and insulation design. The second part examines the integrated propulsion chain, from the LH 2 reservoir to the fuel cell, including hydrogen transfer through an instrumented line and heat exchanger. The system delivers over 14,000 Wh of electrical energy, enabling ranges up to 4,400 km for a 4 m fixed-wing UAV with flight speeds of 24–27 m/s. A first-order theoretical model is introduced to support preliminary sizing, mass estimation, and boil-off prediction. These results demonstrate clear endurance advantages of LH 2 storage over compressed hydrogen systems. • LH 2 system for UAVs enables multi-day flight with up to 50 h boil-off endurance. • Tanks with same gravimetric index show varied boil-off due to internal design differences. • Complete LH 2 propulsion chain tested, delivering over 14 kWh for long-range flight. • Simplified model aids LH 2 tank sizing, mass estimation and boil-off prediction.

The journal retracts the article titled “Prediction of Urban Air Mobility and Drone Accident Rates and the Role of Urban Management Systems” [...]

Functional bowel disorders (FBDs) are chronic gastrointestinal conditions characterized by recurrent symptoms associated with gut microbiota dysbiosis. Although accumulating evidence suggests that probiotics can improve symptoms in patients with FBD, the underlying mechanisms remain to be fully elucidated. In this randomized, double-blind, placebo-controlled clinical trial, 38 adults meeting the Rome IV diagnostic criteria of functional constipation (FC) and functional diarrhea (FD) received either a multi-strain probiotic complex or placebo for 8 weeks. Clinical outcomes were evaluated using the Irritable Bowel Syndrome Severity Scoring System (IBS-SSS), bowel habits questionnaire, and IBS Quality of Life (IBS-QoL) instrument. Fecal samples were collected at baseline and at week 8 for gut microbiota profiling via 16S rRNA gene sequencing and metabolomic analysis using gas chromatography–mass spectrometry. Probiotic supplementation significantly reduced the severity of abdominal bloating and its interference with quality of life, and improved the body image domain of the IBS-QoL. Beta diversity analysis showed significant temporal shifts in the probiotic group, while 16S rRNA sequencing revealed an increased relative abundance of Faecalibacterium prausnitzii and Blautia stercoris. Fecal metabolomic analysis further indicated elevated levels of metabolites implicated in the gut–brain axis. Multi-strain probiotic supplementation alleviated gastrointestinal symptoms and improved aspects of psychosocial well-being in adults with FBDs, potentially through modulation of the human gut microbiome.

In this paper, we propose a simple and low-cost method to control multiple Hall sensor boards in a Linear Motion System (LMS). In the return section of the system, precise position control is not required. So, we use only one inverter board to read data from several sensor boards using a daisy-chain connection. This design helps reduce the cost and makes the system easier to build. However, speed errors can happen when the carrier moves from one sensor board to another. To resolve this problem, we use linear interpolation and third-order polynomial interpolation. Experimental results show the validity of the proposed method.

This study aimed to examine the mediating effect of job failure experiences and recognizing the cause of failure in the job search process after college graduation. This study confirmed the statistical significance of the parameters through the Baron and Kenny (1986) three-step mediating effect analysis method. In Step 1, the effect of the job search activities on the job search failure experience through the mediation of their job search failure experience was examined, and the analysis results revealed the static effect of the college graduates' willingness to work (β=.133, p<.05). In Step 2, the static effect of the job search activities was confirmed on the college graduates' willingness to work (β=.086, p<.01). In Step 3, analysis results showed that the job search activities had a mediating effect by mediating the experience of job search failure and influencing the college graduates' willingness to work. Additionally, the research model was revised based on the results of analyzing the partial mediating effect of recognizing the cause of failure in the relationship between the job search failure experience and the willingness to work.

ABSTRACT Cities worldwide are rapidly integrating urban management information technology (IT) systems to address increasing urban challenges effectively. This paper examines the evolution of these systems, from the Ubiquitous City (U-City) to contemporary Smart Cities, and explores emerging technologies like the Metaverse and Digital Twin. Despite their growing relevance, there is ambiguity in their conceptual definitions and how they are applied interchangeably in urban management contexts. This study aims to clarify these technologies by analyzing U-City, Smart City, Metaverse, and Digital Twin within an Analysis Framework of Urban Management IT Systems. Our analysis reveals distinct roles and interconnections among these technologies. U-City initiated the development of essential IT infrastructure, laying the groundwork for subsequent systems. Smart City technology, leveraging the infrastructure provided by U-City, addresses real urban issues but lacks predictive capabilities for future challenges. In contrast, the Metaverse facilitates the simulation of urban changes and planning in a virtual environment, influencing real-world city development. Digital Twin technology enhances the operational efficiency of U-City and Smart City by simulating real-world data and optimizing urban management processes. The study highlights that while U-City and Smart City function in the tangible realm, Metaverse and Digital Twin operate in the virtual domain, yet they are closely integrated. Metaverse assists in urban planning through simulations that inform real-world Smart City designs, while Digital Twin optimizes real-time city operations and informs Metaverse simulations for future planning. The findings underscore the importance of understanding these technologies’ unique contributions and their interplay. Although current urban management IT systems have limitations, especially in technology classification and data accessibility, this research paves the way for future investigations. Further research should focus on refining the definitions and applications of Metaverse and Digital Twin, clarifying their relationships with Smart City and U-City, and addressing security and privacy concerns associated with these technologies.