• Steel and Composite Structures
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• v.51 no.2
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• pp.185-202
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• 2024

In this research paper, and for the first time, wave propagations in sigmoidal imperfect functionally graded material plates are investigated using a simplified quasi-three-dimensionally higher shear deformation theory (Quasi-3D HSDTs). By employing an indeterminate integral for the transverse displacement in the shear components, the number of unknowns and governing equations in the current theory is reduced, thereby simplifying its application. Consequently, the present theories exhibit five fewer unknown variables compared to other Quasi-3D theories documented in the literature, eliminating the need for any correction coefficients as seen in the first shear deformation theory. The material properties of the functionally graded plates smoothly vary across the cross-section according to a sigmoid power law. The plates are considered imperfect, indicating a pore distribution throughout their thickness. The distribution of porosities is categorized into two types: even or uneven, with linear (L)-Type, exponential (E)-Type, logarithmic (Log)-Type, and Sinus (S)-Type distributions. The current quasi-3D shear deformation theories are applied to formulate governing equations for determining wave frequencies, and phase velocities are derived using Hamilton's principle. Dispersion relations are assumed as an analytical solution, and they are applied to obtain wave frequencies and phase velocities. A comprehensive parametric study is conducted to elucidate the influences of wavenumber, volume fraction, thickness ratio, and types of porosity distributions on wave propagation and phase velocities of the S-FGM plate. The findings of this investigation hold potential utility for studying and designing techniques for ultrasonic inspection and structural health monitoring.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.244-252
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• 2023

Objective: We evaluated the efficacy of the newly developed optimized in vitro culture (OIVC) dish for cultivating preimplantation mouse embryos. This dish minimizes the need for mineral oil and incorporates microwells, providing a stable culture environment and enabling independent monitoring of individual embryos. Methods: Mouse pronuclear (PN) zygotes and two-cell-stage embryos were collected at 18 and 46 hours after human chorionic gonadotropin injection, respectively. These were cultured for 120 hours using potassium simplex optimized medium (KSOM) to reach the blastocyst stage. The embryos were randomly allocated into three groups, each cultured in one of three dishes: a 60-mm culture dish, a microdrop dish, and an OIVC dish that we developed. Results: The OIVC dish effectively maintained the osmolarity of the KSOM culture medium over a 5-day period using only 2 mL of mineral oil. This contrasts with the significant osmolarity increase observed in the 60-mm culture dish. Additionally, the OIVC dish exhibited higher blastulation rates from two-cell embryos (100%) relative to the other dish types. Moreover, blastocysts derived from both PN zygotes and two-cell embryos in the OIVC dish group demonstrated significantly elevated mean cell numbers. Conclusion: Use of the OIVC dish markedly increased the number of cells in blastocysts derived from the in vitro culture of preimplantation mouse embryos. The capacity of this dish to maintain medium osmolarity with minimal mineral oil usage represents a breakthrough that may advance embryo culture techniques for various mammals, including human in vitro fertilization and embryo transfer programs.

• Journal of Food Hygiene and Safety
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• v.39 no.5
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• pp.463-466
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• 2024

Marine microalgal biotoxins can accumulate in seafoods, posing significant risk to human health. These toxins include tetrodotoxin (TTX) and can cause paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). With accelerating climate change, the frequency and intensity of harmful algal blooms capable of producing biotoxins have increased. In South Korea, the Ministry of Food and Drug Safety (MFDS) regulates traditional toxins, including TTX and toxins causing PSP, DSP, and ASP. In contrast, the U.S. Food and Drug Administration (FDA) and European Food Safety Authority (EFSA) have established regulatory standards for a broader spectrum of marine biotoxins, including yessotoxins (YTXs), brevetoxins (BTXs), azaspiracids (AZAs), and ciguatoxins (CTXs), to ensure seafood safety. To effectively address this global concern, the MFDS launched an R&D project entitled "Establishment of the Safety Management System for Marine Biotoxins" (2020-2024). This project focused on enhancing analytical methods to detect unregulated toxins, assessing contamination levels, and developing rapid detection techniques. The project proposal emphasizes the need to establish a comprehensive monitoring system to mitigate future risks, particularly as climate change expands the range of toxic marine species. This project aims to advance our understanding of marine biotoxin contamination and strengthen seafood safety measures in South Korea by aligning them with international standards. This special issue compiles knowledge accumulated and technical advancements related to marine biotoxins, stemming from the outcomes of this project. It includes 12 papers describing analyses of various regulated and unregulated marine biotoxins, the current prevalence of seafood contamination, toxicity assessments, rapid analytical methods, and the state of safety management.

• Geomechanics and Engineering
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• v.39 no.3
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• pp.283-303
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• 2024

In large-scale engineering construction, there are many cases of highly concealed adverse geological phenomena (HCAGP) at certain scale that are not revealed until excavation. It is crucial to ascertain their geological characteristics and rapidly formulate treatment since they often have enormous negative impacts on the project. However, conventional exploration and evaluation methods are not suitable for HCAGP due to the long acquisition time and strict requirements. Therefore, this paper proposes a dynamic-tracking investigation and evaluation method (DTIEM), which carries out a series of fast and effective techniques, including down-the-hole (DTH) drilling, cross-inclined holes, seismic tomography and P-wave velocity (V_P) tests, for preliminary data of HCAGP. Then, an initial treatment plan is proposed to guide the construction. Subsequently, the initial data of the HCAGP are tracked and revised until the end of construction. This method was applied to a deep groove at a hydropower station, which was exposed when the excavation of dam section 11. The results show that by using the DTIEM, the preliminary engineering characteristics of the deep groove were obtained quickly. The rock mass quality of the top deep groove was grade III₂ with 9.82 GPa, the middle part was grade III₁ with 15.07 GPa, and the bottom part was grade II with 19.68 GPa. The quality of rock mass gradually increases with the increase of depth. From the numerical simulation, the maximum additional displacement is about 20 mm at the dam crest, 4 ~ 7 mm at the dam heel, and 2 ~ 5 mm at the dam toe. The numerical simulation and monitoring results show that the stress and strain of the dam and foundation are within a safe range in each stage. Thus, the proposed method is feasible.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.7
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• pp.1968-1985
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• 2024

At present, the world is witnessing a rapid change in all the fields of human civilization business interests and goals of all the sectors are changing very fast. Global changes are taking place quickly in all fields - manufacturing, service, agriculture, and external sectors. There are plenty of hurdles in the emerging technologies in agriculture in the modern days. While adopting such technologies as transparency and trust issues among stakeholders, there arises a pressurized necessity on food suppliers because it has to create sustainable systems not only addressing demand-supply disparities but also ensuring food authenticity. Recent studies have attempted to explore the potential of technologies like blockchain and practices for smart and sustainable agriculture. Besides, this well-researched work investigates how a scientific cum technological blockchain architecture addresses supply chain challenges in Precision Agriculture to take up challenges related to transparency traceability, and security. A robust registration phase, efficient authentication mechanisms, and optimized data management strategies are the key components of the proposed architecture. Through secured key exchange mechanisms and encryption techniques, client's identities are verified with inevitable complexity. The confluence of IoT and blockchain technologies that set up modern farms amplify control within supply chain networks. The practical manifestation of the researchers' novel blockchain architecture that has been executed on the Hyperledger network, exposes a clear validation using corroboration of concept. Through exhaustive experimental analyses that encompass, transaction confirmation time and scalability metrics, the proposed architecture not only demonstrates efficiency but also underscores its usability to meet the demands of contemporary Precision Agriculture systems. However, the scholarly paper based upon a comprehensive overview resolves a solution as a fruitful and impactful contribution to blockchain applications in agriculture supply chains.

• Journal of Radiation Protection and Research
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• v.49 no.3
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• pp.102-113
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• 2024

Diffusing alpha-emitters radiation therapy (DaRT) represents a groundbreaking development in cancer therapy, offering a solution to the limitations of conventional radiation therapy. By deploying ²²⁴Ra embedded seeds, DaRT achieves targeted delivery of high-dose alpha particles directly to tumor sites, showing considerable efficacy in tumor control and minimal damage to adjacent healthy tissues. This comprehensive review analyzes the published literature regarding mechanisms, seed production, dose calculation, measurement, and biological experiments related to DaRT. It includes in-depth discussions on mathematical models, Monte Carlo simulations for dose distribution, real-time in vivo dosimetry developments, and biological experiments both in vitro and in vivo. Clinical trial outcomes are also examined to evaluate the therapy's effectiveness in various cancer types. DaRT utilizes ²²⁴Ra-labeled seeds, using the decay chain of ²²⁴Ra to deliver alpha particles effectively within a tumor. Several asymptotic diffusion-leakage models were developed to calculate the alpha dose distribution of DaRT. In vivo dosimetry techniques have been developed for real-time monitoring. Biological experiments demonstrated the cytotoxic effects of DaRT across various cancer cells, with varying radiosensitivity. Additionally, the enhanced effects of combined therapy with chemotherapy and immunotherapy were suggested by many in vivo studies. Clinical trials have shown high complete response rate in squamous cell carcinoma, with minimal side effects, suggesting DaRT's feasibility and safety. DaRT emerges as a highly localized cancer treatment method with minimal side effects compared to traditional radiation therapy. It directly ablates tumors and potentially enhances immune responses, indicating a significant advance in cancer therapy. Future research and ongoing clinical trials will further elucidate its efficacy across different cancer types and in combination with other treatments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.1-9
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• 2024

New motor development requires high-speed load testing using dynamo equipment to calculate the efficiency of the motor. Abnormal noise and vibration may occur in the test equipment rotating at high speed due to misalignment of the connecting shaft or looseness of the fixation, which may lead to safety accidents. In this study, three single-axis vibration sensors for X, Y, and Z axes were attached on the surface of the test motor to measure the vibration value of vibration. Analog data collected from these sensors was used in classification models for anomaly detection. Since the classification accuracy was around only 93%, commonly used hyperparameter optimization techniques such as Grid search, Random search, and Bayesian Optimization were applied to increase accuracy. In addition, Response Surface Method based on Design of Experiment was also used for hyperparameter optimization. However, it was found that there were limits to improving accuracy with these methods. The reason is that the sampling data from an analog signal does not reflect the patterns hidden in the signal. Therefore, in order to find pattern information of the sampling data, we obtained descriptive statistics such as mean, variance, skewness, kurtosis, and percentiles of the analog data, and applied them to the classification models. Classification models using descriptive statistics showed excellent performance improvement. The developed model can be used as a monitoring system that detects abnormal conditions of the motor test.

• Smart Structures and Systems
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• v.33 no.4
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• pp.291-300
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• 2024

Uncertainty of the model, system delay and drive dynamics can be considered as normal uncertainties, and the main source of uncertainty in the seismic control system is related to the nature of the simulated seismic error. In this case, optimizing the management strategy for one particular seismic record will not yield the best results for another. In this article, we propose a framework for online management of active structural management systems with seismic uncertainty. For this purpose, the concept of reinforcement learning is used for online optimization of active crowd management software. The controller consists of a differential controller, an unplanned gain ratio, the gain of which is enhanced using an online reinforcement learning algorithm. In addition, the proposed controller includes a dynamic status forecaster to solve the delay problem. To evaluate the performance of the proposed controllers, thousands of ground motion data sets were processed and grouped according to their spectrum using fuzzy clustering techniques with spatial hazard estimation. Finally, the controller is implemented in a laboratory scale configuration and its operation is simulated on a vibration table using cluster location and some actual seismic data. The test results show that the proposed controller effectively withstands strong seismic interference with delay. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Simulation results is believed to achieved in the near future by the ongoing development of AI and control theory.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1313-1313
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• 2024

This paper proposes the development of an advanced Risk Management System (RMS) using Risk-Based Methodologies (RBM) specifically tailored for addressing construction defects in industrial plants. Urbanization and industrialization demand robust frameworks to handle the complexities and safety concerns in construction projects. Traditional risk management often overlooks critical aspects such as persistent construction defects. This paper discusses the development of an innovative Risk Management System (RMS) that integrates Risk-Based Methodologies (RBM) specifically for construction defect mitigation in industrial settings. The study centers around the implementation of Risk-Based Inspection (RBI) techniques, tailored to enhance traditional risk management systems. This includes developing a specialized risk assessment tool alongside an online management platform, designed to provide continuous monitoring and comprehensive management of construction risks. The proposed system-RBE-i (Risk-Based Execution for Installation)-focuses on identifying, evaluating, and mitigating risks effectively, utilizing a systematic approach that integrates seamlessly into existing construction workflows. The RBE-i system's core lies in its ability to conduct thorough risk analyses and real-time data provision. It uses digital technologies to improve communication, operational efficiency, and decision-making processes across construction projects. By applying these methodologies, the system enhances safety and ensures more efficient project execution by preemptively identifying potential risks and addressing them promptly. Field applications of RBE-i have demonstrated its effectiveness in significantly reducing construction defects, thus validating its potential as a transformative tool in construction risk management. The system sets new industry standards by shifting from reactive to proactive risk management practices, ultimately leading to safer, more reliable, and cost-effective construction operations. In conclusion, the RMS developed through this study not only addresses the pressing needs of construction risk management but also proposes a paradigm shift towards more proactive, structured, and technology-driven practices. The successful integration of the RBE-i system across various pilot projects illustrates its significant potential to improve overall project outcomes, making it an invaluable addition to the field of construction management.

• Journal of Veterinary Science
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• v.25 no.5
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• pp.65.1-65.11
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• 2024

Importance: Recent developments in genetic analytical techniques have enabled the comprehensive analysis of gastrointestinal symbiotic bacteria as a screening tool for animal health conditions, especially the endangered gibbons at the National Wildlife Rescue Centre (NWRC). Objective: High-throughput sequencing based on 16S ribosomal RNA genes was used to determine the baseline gut bacterial composition and identify potential pathogenic bacteria among three endangered gibbons housed in the NWRC. Methods: Feces were collected from 14 individuals (Hylobates lar, n = 9; Hylobates agilis, n = 4; and Symphalangus syndactylus, n = 1) from March to November 2022. Amplicon sequencing were conducted by targeting V3-V4 region. Results: The fecal microbial community of the study gibbons was dominated by Bacteroidetes and Firmicutes (phylum level), Prevotellaceae and Lachnospiraceae/Muribaculaceae (family level), and Prevotella (and its subgroups) (genera level). This trend suggests that the microbial community composition of the study gibbons differed insignificantly from previously reported conspecific or closely related gibbon species. Conclusions and Relevance: This study showed no serious health problems that require immediate attention. However, relatively low alpha diversity and few potential bacteria related to gastrointestinal diseases and streptococcal infections were detected. Information on microbial composition is essential as a guideline to sustain a healthy gut condition of captive gibbons in NWRC, especially before releasing this primate back into the wild or semi-wild environment. Further enhanced husbandry environments in the NWRC are expected through continuous health monitoring and increase diversity of the gut microbiota through diet diversification.