With the development of maritime technology and equipment, most ships are equipped with an automatic identification system (AIS) to store navigation information. Over time, the size of the data ...increases, rendering its storage and processing difficult. Hence, it is necessary to transform the AIS data into trajectories, and then simplify the AIS trajectories to remove unnecessary information that is not related to route shape. Moreover, topographic information must be considered because otherwise, the simplified trajectory can intersect obstacles. In this study, we propose an AIS trajectory simplification algorithm considering topographic information. The proposed algorithm simplifies the trajectories without the intersection of the trajectory and obstacle using the improved Douglas–Peucker algorithm. Polygon map random (PMR) quadtree was used to consider topographic information on the coast, and the intersection between topographic information and simplified trajectories was efficiently computed using the PMR quadtree. To verify the effectiveness of the proposed algorithm, experiments were conducted on real-world trajectories in the Korean sea. The proposed algorithm yielded simplified trajectories with no intersections of the trajectory and obstacle. In addition, the computational efficiency of the proposed algorithm with the PMR quadtree was superior to that without the PMR quadtree.
To reduce the environmental impact of concrete, recycled aggregates are of significant interest. Recycled concrete aggregate (RCA) presents a significant resource opportunity, although its ...performance as an aggregate in concrete is variable. This study presents a meta-analysis of the published literature to refine the understanding of how the moisture content of RCA, as well as other parameters, affects the compressive strength of concrete. Seven machine learning models were used to predict the compressive strength of concrete with RCA, including linear regression, support vector regression (SVR), and k-nearest neighbors (KNN) as single models, and decision tree, random forest, XGBoost, and LightGBM as ensemble models. The results of this study demonstrate that ensemble models, particularly the LightGBM model, exhibited superior prediction accuracy compared to single models. The LightGBM model yielded the highest prediction accuracy with R2 = 0.94, RMSE = 4.16 MPa, MAE = 3.03 MPa, and Delta RMSE = 1.4 MPa, making it the selected final model. The study, employing feature importance with LightGBM as the final model, identified age, water/cement ratio, and fine RCA aggregate content as key factors influencing compressive strength in concrete with RCA. In an interaction plot analysis using the final model, lowering the water–cement ratio consistently improved compressive strength, especially between 0.3 and 0.4, while increasing the fine RCA ratio decreased compressive strength, particularly in the range of 0.4 to 0.6. Additionally, it was found that maintaining moisture conditions of RCA typically between 0.0 and 0.8 was crucial for maximizing strength, whereas extreme moisture conditions, like fully saturated surface dry (SSD) state, negatively impacted strength.
In recent tracheal tissue engineering, limitations in cartilage reconstruction, caused by immature delivery of chondrocyte-laden components, have been reported beyond the complete epithelialization ...and integration of the tracheal substitutes with the host tissue. In an attempt to overcome such limitations, this article introduces a protective design of tissue-engineered trachea (TraCHIM) composed of a chitosan-based nanofiber membrane (CHIM) and a 3D-printed biotracheal construct. The CHIM was created from chitosan and polycaprolactone (PCL) using an electrospinning process. Upon addition of chitosan to PCL, the diameter of electrospun fibers became thinner, allowing them to be stacked more closely, thereby improving its mechanical properties. Chitosan also enhances the hydrophilicity of the membranes, preventing them from slipping and delaminating over the cell-laden bioink of the biotracheal graft, as well as protecting the construct. Two weeks after implantation in Sprague-Dawley male rats, the group with the TraCHIM exhibited a higher number of chondrocytes, with enhanced chondrogenic performance, than the control group without the membrane. This study successfully demonstrates enhanced chondrogenic performance of TraCHIM in vivo. The protective design of TraCHIM opens a new avenue in engineered tissue research, which requires faster tissue formation from 3D biodegradable materials, to achieve complete replacement of diseased tissue.
•EV charging is considered to mitigate energy waste and economic losses due to renewable energy curtailment.•An elasticity-based EV response model considering time pressure and charging pressure is ...proposed.•A charging point operator’s location-based incentive algorithm is proposed considering distribution system stability.•The proposed method can economically manage the renewable energy curtailment and distribution system stability.
There have recently been an increasing number of variable renewable energy curtailment cases to manage power system stability problems caused by the overproduction of variable renewable energy. Variable renewable energy curtailment can be a factor that hinders the development of the power industry by reducing the economic viability of variable renewable energy operators and the efficiency of energy use. In this study, an economic curtailment methodology using electric vehicles to mitigate energy waste and economic losses is proposed. Charging point operators participate in incentive-based demand response programs with their charging station loads under curtailment situations. A location-based incentive algorithm considering distribution system constraints is proposed to avoid distribution system congestion. A response model based on random arrival electric vehicles considering demand and price elasticity, time pressure, and charging pressure is developed. The proposed methodology is verified through case studies based on the environment of Jeju Island in Korea. The case study results show that the proposed methodology can use energy more economically and effectively than conventional variable renewable energy curtailment methodology.
Objectives
Persistent postural‐perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter ...study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration.
Methods
Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments.
Results
Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space‐motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD.
Conclusion
This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.
•Quantitative investigation of curing temperature for FA-based geopolymer strength.•Various micro-observation results through EDA, XRD, SEM, MIP.•Strength grading contour considering ...alkali-activators, Ms values, and curing temperatures.•Relationship between strength and changes in macro-pore structure.•Pre-curing effect with different temperature and duration on strength.
Many researches have been performed on performance improvement of geopolymer considering low calcium materials and alkaline solutions. In the binder of geopolymer, OPC (Ordinary Portland Cement) which can cause environmental load such as CO2 emission is not used. The mechanical properties of geopolymer are directly affected by various parameters like binder types, SiO2/Na2O molar ratios, alkali activator concentrations, and curing conditions (temperature and period), but very limited researches have been performed on comprehensive evaluation of the influencing parameters.
In the work, compressive strength in FA (Fly Ash)-based geopolymer is evaluated considering four test variables covering Na2O content, SiO2/Na2O molar ratios, curing temperature/period, and pre-curing temperature/period. The results reveal that higher compressive strength can be obtained with higher Na2O content, higher curing temperatures, and longer pre-curing periods at the relatively low temperature (23°C). On the other hand, an extension of curing period at high temperatures leads to strength reduction due to increasing macro-pores over 50nm. Through the various tests, strength grade contours considering SiO2/Na2O molar ratios, Na2O content, and curing temperatures are obtained, which can be utilized for an effective mix design for FA-based geopolymer.
Due to a superior dose conformity to the target, proton beam therapy (PBT) continues to rise in popularity. Recently, considerable efforts have been directed toward discovering treatment options for ...use in combination with PBT. This study aimed to investigate the targeting of checkpoint kinase 1 (CHK1), a critical player regulating the G2/M checkpoint, as a promising strategy to potentiate PBT in human triple-negative breast cancer (TNBC) cells. Protons induced cell-cycle arrest at the G2/M checkpoint more readily in response to increased CHK1 activation than X-rays. A clonogenic survival assay revealed that CHK1 inhibition using PF-477736 or small interfering RNA (siRNA) enhanced the sensitivity toward protons to a greater extent than toward X-rays. Western blotting demonstrated that PF-477736 treatment in the background of proton irradiation increased the pro-apoptotic signaling, which was further supported by flow cytometry using annexin V. Immunofluorescence revealed that proton-induced DNA double-strand breaks (DSBs) were further enhanced by PF-477736, which was linked to the downregulation of Rad51, essential for the homologous recombination repair of DSBs. Direct inactivation of Rad51 resulted in enhanced proton sensitization. Collectively, these data suggest that targeting CHK1 may be a promising approach for improving PBT efficacy in the treatment of TNBC.
Although the concurrent use of a chemotherapeutic agent and radiotherapy improves survival in patients with locally advanced or recurrent cervical cancer, severe side effects related to chemotherapy ...are frequent and may result in a low quality of life for the patients. In this study, we investigated the effects of a combination of Wee1 inhibitor (AZD1775) and irradiation in cervical cancer. In vitro effects of AZD1775 with irradiation in human cervical cancer cells were assessed by clonogenic survival and apoptosis assays. The effects on DNA damage response signaling and the cell cycle were also explored. Tumor growth delay was evaluated to investigate the in vivo effects of AZD1775 with irradiation in cervical cancer mouse models, including xenografts and patient-derived xenografts (PDXs). The co-treatment of AZD1775 and irradiation significantly decreased clonogenic survival and increased apoptosis in cervical cancer cells. These effects were associated with G2 checkpoint abrogation which resulted in persistent DNA damage. Both in the xenografts and the PDXs, the co-treatment significantly decreased tumor growth compared tothe irradiation alone (p < 0.05). These results demonstrate that the Wee1 inhibitor (AZD1775) can be considered as a potential alternative as a radiosensitizer in cervical cancer instead of a chemotherapeutic agent such as cisplatin.
This study aimed to identify the whole innervation pattern of the platysma using the Sihler's staining, and the axonal composition profile of the sensory‐motor anastomosis identified by ...immunofluorescence assays. The findings provide a comprehensive understanding of the neural anatomy of the platysma and facilitate efficient and safe manipulation for neurotoxin injection. Ten fixed and two fresh hemifaces were included in this study. Sihler's staining was used to the study 10 fixed hemifaces and two fresh hemifaces were used for immunofluorescence assays. In all cases, the cervical branch of facial nerve (Cbr) broadly innervated the platysma, and the marginal mandibular branch of facial nerve (MMbr) provided supplementary innervation to the uppermost part of the platysma. The transverse cervical nerve (TCN), great auricular nerve (GAN), and supraclavicular nerve (SCN) were observed in the lower half of the platysma. In 30% of all cases, there was a communicating loop between the Cbr and TCN. In 20% of all the cases, a communicating branch joined between the Cbr and GAN. For successful esthetic rejuvenation procedures, a clinician should consider the Cbr distribution to the overall platysma and additionally innervation by individual nerves (MMbr, GAN, TCN, and SCN) to the middle and lower portions of the platysma muscle.
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