• International conference on construction engineering and project management
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• 2009.05a
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• pp.550-557
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• 2009

The concepts of 'sustainable development', 'sustainable construction' and 'green building' have been elevated to priority levels in all types and phases of construction project development worldwide. Consultants and contractors are now required to seriously consider the impact of their operations on the natural environment and the society, and consequently adopt sustainable construction practices in the development process to minimize and mitigate the negative impacts of their activities. However, existing sustainability rating tools apply to the design, post-construction and operation phases of a building; no tool exists for the rating of the performance of the contractor or the project team at the construction phase. This study aimed to develop a model for evaluating the sustainability of construction operations, drawing on the global best practice standards on sustainability. Practical applications of the model were carried out through case studies to evaluate the performances of fifteen construction firms in New Zealand. The developed model and the outcomes of the case studies were presented, including potential areas of weaknesses, strengths, constraints to achievement or adoption of sustainable construction practices and areas for improvement in the operations of the firms. The successful application of the developed model in practice shows its usefulness and ease of application. It is therefore recommended for adoption as a simple but effective system for measuring and reporting on sustainability performance or sustainability of construction operations of firms in New Zealand and elsewhere.

• ETRI Journal
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• v.45 no.1
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• pp.105-118
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• 2023

We tested the feasibility of automated discrimination of patients with panic disorder (PD) from healthy controls (HCs) based on multimodal physiological responses using machine learning. Electrocardiogram (ECG), electrodermal activity (EDA), respiration (RESP), and peripheral temperature (PT) of the participants were measured during three experimental phases: rest, stress, and recovery. Eleven physiological features were extracted from each phase and used as input data. Logistic regression (LoR), k-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and multilayer perceptron (MLP) algorithms were implemented with nested cross-validation. Linear regression analysis showed that ECG and PT features obtained in the stress and recovery phases were significant predictors of PD. We achieved the highest accuracy (75.61%) with MLP using all 33 features. With the exception of MLP, applying the significant predictors led to a higher accuracy than using 24 ECG features. These results suggest that combining multimodal physiological signals measured during various states of autonomic arousal has the potential to differentiate patients with PD from HCs.

• Current Photovoltaic Research
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• v.11 no.1
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• pp.18-26
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• 2023

Tin perovskite solar cells have attracted a lot of attention due to their potential to address the toxicity of lead, which is the biggest barrier to commercialization of perovskite solar cells. Unlike other lead-free perovskite, tin perovskite have a direct bandgap, which is suitable for use as light harvesting, and relatively good stability, which has led to a lot of attention. Since the first tin perovskite solar cell was reported in 2014, it has achieved an impressive power conversion efficiency of 14.81%. However, this efficiency is still low compared to that of lead perovskite solar cells, and the stability of tin perovskite solar cells is also an issue that needs to be addressed. In this review, we will discuss the basic properties of the tin atom in comparison to the lead atom, and then discuss the crystal structure, phase transition, and basic properties of tin perovskite. We will then discuss the advantages, applications, challenges, and strategies of tin perovskite, In particular, we will focus on how to prevent the oxidation of tin, which is arguably the biggest challenge for using tin perovskite solar cells. At the end, we summarize the key factors that need to be addressed for higher efficiency and stability, emphasizing what is needed to commercialize tin perovskite solar cells.

• Journal of Sensor Science and Technology
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• v.32 no.3
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• pp.199-206
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• 2023

This study presents a novel monitoring technique for underwater high-voltage direct current (HVDC) cables based on the Distributed Acoustic Sensor (DAS). The proposed technique utilizes vibration and acoustic signals generated on HVDC cables to monitor their condition and detect events such as earthquakes, shipments, tidal currents, and construction activities. To implement the monitoring system, a DAS based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) system was designed, fabricated, and validated for performance. For the HVDC cable monitoring experiments, a testbed was constructed on land, mimicking the cable burial method and protective equipment used underwater. Defined various scenarios that could cause cable damage and conducted experiments accordingly. The developed DAS system achieved a maximum measurement distance of 50 km, a distance measurement interval of 2 m, and a measurement repetition rate of 1 kHz. Extensive experiments conducted on HVDC cables and protective facilities demonstrated the practical potential of the DAS system for monitoring underwater and underground areas.

• Analytical Science and Technology
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• v.36 no.1
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• pp.53-58
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• 2023

2'-Hydroxy-3',4'-methylenedioxy-3,4,5-trimethoxychalcone (HMTC) is a newly synthesized chalcone that affects proliferation, cytotoxic potential and apoptosis in human leukemia cells. However, no validated determination method has been described so far for HMTC in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry to determine HMTC in rat plasma. Liquid-liquid extraction with ethyl acetate was used for the clean-up procedure. The analyte was separated on a reversedphase column with mobile phase of distilled water and acetonitrile (2:8, v/v, including 0.1 % formic acid). The ion transition of the precursor to the product ion was principally deprotonated ions [M-H]^- at m/z 356.8 → 327.2 for HMTC. This analytical method was successfully applied in pharmacokinetic study of HMTC after intravenous administration in rats.

• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.418-424
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• 2023

Natural killer (NK) cells play a crucial role in combating infections and tumors. However, their therapeutic application in solid tumors is hindered by challenges, such as limited lifespan, tumor penetration, and delivery precision. Our research introduces a novel ultrasonic actuation technique to navigate NK cells more effectively in the vascular system, particularly at vessel bifurcations where targeted delivery is most problematic. We use a hemispherical ultrasonic transducer array that generates phase-modulated traveling waves, focusing on an ultrasound beam to steer NK cells using blood-flow dynamics and a focused acoustic field. This method enables the precise obstruction of non-target vessels and efficiently directs NK cells toward the tumor site. The simulation results offer insights into the behavior of NK cells under various conditions of cell size, radiation pressure, and fluid velocity, which inform the optimization of their trajectories and increase targeting efficiency. The experimental results demonstrate the feasibility of this ultrasonic approach for enhancing NK cell targeting, suggesting a potential leap forward in solid tumor immunotherapy. This study represents a significant step in NK cell therapeutic strategies, offering a viable solution to the existing limitations and promising enhancement of the efficacy of cancer treatments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.26-35
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• 2024

Aluminum-induced crystallization (AIC) as a route to reduce the fabrication cost and to obtain polycrystalline Si (p-Si) thin-film of large grain size is a promising alternative of single-crystalline (s-Si) substrate or p-Si thin-film obtained by conventional methods such as solid phase crystallization (SPC) and laser-induced crystallization (LIC). As the AIC process occurs at the interface between a-Si and Al thin-films, there are various process and interface parameters. Also, it directly means that there is a certain parametric window to obtain p-Si of large grain size having uniform crystal orientation. In this article, we investigate the effect of the various process and interface parameters to obtain p-Si of large grain size and uniform crystal orientation from the literature review. We also suggest the potential use of the p-Si as a virtual substrate for the growth of various compound semiconductors in a form of low-dimension as well as thin-film as a way for their monolithic integration on Si.

• Archives of Obesity and Metabolism
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• v.2 no.2
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• pp.45-53
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• 2023

Despite the emergence of obesity as a significant public health concern, artificial sweeteners have made their way into various food products due to the perception, that they serve as substitutes for sugar. Artificial sweeteners are used to supposedly achieve weight management and health improvement. However, their efficacy and safety remain debatable. Commonly used artificial sweeteners include aspartame, acesulfame potassium, saccharin, and sucralose. This article discusses the effects of artificial sweetener consumption on weight loss, appetite regulation, blood glucose control, and gut microbiota. Research findings, concerning the consumption of artificial sweeteners and their association with body weight, have shown inconsistencies between randomized controlled trials and cohort studies. Studies, comparing artificial sweeteners to sugar, have reported no significant differences in satiety. Although artificial sweeteners have no calories, they can affect blood sugar levels through the cephalic phase insulin response. A recent study suggested that artificial sweeteners influenced the occurrence of diabetes. Due to limitations in the study design, excluding diabetes-influencing factors was not feasible. The evidence showed that artificial sweeteners harbored potential health risks, necessitating further investigation. According to recent studies, the consumption of artificial sweeteners was associated with gut microbiota changes and individual blood sugar responses. It is important to note that artificial sweeteners cannot be considered safe alternatives to sugar, and further research is required.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1067-1086
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• 2023

With rapid advances in meat science in recent decades, changes in meat quality during the pre-slaughter phase of muscle growth and the post-slaughter process from muscle to meat have been investigated. Commonly used techniques have evolved from early physicochemical indicators such as meat color, tenderness, water holding capacity, flavor, and pH to various omic tools such as genomics, transcriptomics, proteomics, and metabolomics to explore fundamental molecular mechanisms and screen biomarkers related to meat quality and taste characteristics. This review highlights the application of omics and integrated multi-omics in meat quality and taste characteristics studies. It also discusses challenges and future perspectives of multi-omics technology to improve meat quality and taste. Consequently, multi-omics techniques can elucidate the molecular mechanisms responsible for changes of meat quality at transcriptome, proteome, and metabolome levels. In addition, the application of multi-omics technology has great potential for exploring and identifying biomarkers for meat quality and quality control that can make it easier to optimize production processes in the meat industry.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.6
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• pp.277-283
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• 2023

Vital signals provide essential information regarding the health status of individuals, thereby contributing to health management and medical research. Present monitoring methods, such as ECGs (Electrocardiograms) and smartwatches, demand proximity and fixed postures, which limit their applicability. To address this, Non-contact vital signal measurement methods, such as CW (Continuous-Wave) radar, have emerged as a solution. However, unwanted signal components and a stepwise processing approach lead to errors and limitations in heart rate detection. To overcome these issues, this study introduces an integrated neural network approach that combines noise removal, demodulation, and dominant-frequency detection into a unified process. The neural network employed for signal processing in this research adopts a MLP (Multi-Layer Perceptron) architecture, which analyzes the in-phase and quadrature signals collected within a specified time window, using two distinct input layers. The training of the neural network utilizes CW radar signals and reference heart rates obtained from the ECG. In the experimental evaluation, networks trained on different datasets were compared, and their performance was assessed based on loss and frequency accuracy. The proposed methodology exhibits substantial potential for achieving precise vital signals through non-contact measurements, effectively mitigating the limitations of existing methodologies.