bluuebunny/crossref_metadata_2025 huggingface dataset:
An Improved YOLOV5 Based on Triplet Attention and Prediction Head Optimization for Marine Organism Detection on Underwater Mobile Platforms
Authors: Li Yan , Bai Xinying , Xia Chunlei
Published: September 2022

Machine vision-based automatic detection of marine organisms is a fundamental task for the effective analysis of production and habitat changes in marine ranches. However, challenges of underwater imaging, such as blurring, image degradation, scale variation of marine organisms, and background complexity, have limited the performance of image recognition. To overcome these issues, underwater object detection is implemented by an improved YOLOV5 with an attention mechanism and multiple-scale detection strategies for detecting four types of common marine organisms in the natural scene. An image enhancement module is employed to improve the image quality and extend the observation range. Subsequently, a triplet attention mechanism is introduced to the YOLOV5 model to improve the feature extraction ability. Moreover, the structure of the prediction head of YOLOV5 is optimized to capture small-sized objects. Ablation studies are conducted to analyze and validate the effective performance of each module. Moreover, performance evaluation results demonstrate that our proposed marine organism detection model is superior to the state-of-the-art models in both accuracy and speed. Furthermore, the proposed model is deployed on an embedded device and its processing time is less than 1 s. These results show that the proposed model has the potential for real-time observation by mobile platforms or undersea equipment.
Change of Global Ocean Temperature and Decadal Variability under 1.5 °C Warming in FOAM
Authors: Wu Sheng , Liu Zhengyu , Du Jinbo , Liu Yonggang
Published: September 2022

The rise in atmospheric CO2 concentration is regarded as the dominant reason for observed warming since the mid-20th century. Based on the Paris Agreement target, this research designs three conceptual pathways to achieve the warming target of 1.5 °C above the pre-industrial level by using the Fast Ocean Atmosphere Model. The three different scenarios contain one equilibrium experiment (equilibrium, EQ) and two transient experiments (never-exceed pathway, NE; overshoot pathway, OS). Then, we choose a ten year average that achieves 1.5 °C warming to calculate the climatology of the warming situation. Since OS achieves 1.5 °C twice, we obtain four warming situations to explore the response of ocean temperature. In 2100, the global ocean temperature increases over the global region, except the surface of the Southern Ocean. The difference in heat content mainly depends on the cumulative force of CO2 concentration. It is worth pointing out that during the increase in warming, the ocean surface temperature and heat content start to respond in different hemispheres. The weakening of decadal variability in the North Pacific and North Atlantic is robust in all three scenarios. However, there is a tremendous growth in the low-pass ocean surface temperature standard deviation in the Southern Ocean in EQ, which is different to NE and OS, and causes the increase in global mean total standard deviation. The shortening of decadal variability can only be seen from the EQ power spectrum, while NE and OS have similar power spectra with pre-industrial runs. It suggests that all previous studies that use equilibrium experiments data may have overestimated the shortening of decadal variability under global warming.
Adaptive Formation Control of Multiple Underactuated Autonomous Underwater Vehicles
Authors: Li Ji-Hong , Kang Hyungjoo , Kim Min-Gyu , Lee Mun-Jik , Cho Gun Rae , Jin Han-Sol
Published: September 2022

In this paper, we present a 3D formation control scheme for a group of torpedo-type underactuated autonomous underwater vehicles (AUVs). These multiple AUVs combined with an unmanned surface vessel (USV) construct a sort of star-topology acoustic communication network where the USV is at the center point. Due to this kind of topological feature, this paper applies a virtual school concept. This is a geometric graph where each node is taken as a virtual leader for each specific AUV and assigned its own reference trajectory. For each individual vehicle, its formation strategy is simple: just follow the trajectory of its corresponding virtual leader so as for multiple AUVs to compose the given formation. As for the formation subject, this paper mainly focuses on the formation tracking problem rather than the formation producing. For the torpedo-type vehicle considered in this paper, there are only three control inputs (surge force, pitch, and yaw moments) available for its underwater 3D motion and therefore this is a typical underactuated system. For the following vehicle’s trajectory, a sort of potential field method is used for obstacle avoidance, and a neural network-based adaptive scheme is applied to on-line approximate the vehicle’s unknown nonlinear dynamics, and the uncertainty terms including modeling errors, measurement noises, and external disturbances are handled by the properly designed robust scheme. The proposed formation method can guarantee the uniform ultimate boundedness (UUB) of the closed-loop system. Numerical studies are also carried out to verify the effectiveness of the proposed scheme.
A Robust and Efficient Computational Fluid Dynamics Approach for the Prediction of Horizontal-Axis Wind Turbine Performance
Authors: Popescu Florin , Mahu Răzvan , Rusu Eugen , Ion Ion V.
Published: September 2022

In spite of the tremendous advances in computing power and continuous improvements in simulation software made in recent decades, the accurate estimation of wind turbine performance using numerical methods remains challenging. Wind turbine aerodynamics, especially when operating outside of the design envelope, is highly complex: blade stall, laminar-to-turbulent boundary layer transition, rotational effects (lift augmentation near blade root), and tip losses are present. The scope of this research is to show that the classic Reynolds-Averaged Navier–Stokes (RANS) modeling approach, although extensively tried and tested, is not yet exhausted. The NREL Phase VI rotor was used as a basis for numerical methodology development, verification and validation. The numerical model results are compared in detail with the available measured data, both globally (turbine torque and thrust, and blade bending moment) and locally (pressure coefficient distributions and aerodynamic force coefficients at several locations on the blade) over the entire experimental wind speed range. Stall initiation and spread over the blade span are well captured by the model, and rotor performance is predicted with good accuracy. RANS still presents significant value for wind turbine engineering, with a great balance between accuracy and computational cost. The present work brings potential impact on all applications of wind turbines, especially targeting offshore wind energy extraction for which great development is expected in the near future.
Experimental Study of Supercavitation Bubble Development over Bodies in a Free-Surface Flow
Authors: Arad Ludar Lotan , Gany Alon
Published: September 2022

This research conducts experimental studies on supercavitation bubble development and characteristics within free-surface water and the role of cavitator, comparing the results to those of similar experiments carried on in a duct flow. Tests have been conducted on cylindrical bodies (47 mm diameter) moving underwater at different velocities in a 10-m-diameter circular pool of about 50 cm water level. A comparison has been made for supercavitation bubbles resulting from six different cavitator geometries (flat, sphere, cone, ogive, inverted sphere, and truncated cone). The comparison referred to the conditions of the bubble formation, as well as to the shape and development. It was found that the different cavitators produced different bubble geometries as opposed to the results of experiments conducted in a duct flow by the authors. Nevertheless, the order of onset of cavitation bubble creation (with relation to the cavitation number and flow velocity) was similar. One of the conclusions of this study was that the pressure difference used for defining the cavitation number has a significant impact on the correlation between the bubble characteristics and cavitation number. This fact should be considered when comparing data from different sources.
A K-Means Clustering Algorithm to Determine Representative Operational Profiles of a Ship Using AIS Data
Authors: Park Jongseo , Choi Minjoo
Published: September 2022

Defining the appropriate functional requirements in the early ship design stage is important in order that costs that are caused by the over- or under-specified functional capabilities do not increase. This paper presents a K-means clustering algorithm for the determination of functional requirements. It uses automatic identification system (AIS) data from a reference ship to determine the representative operational profiles, which can support decision-makers in defining the functional requirements of ships that will be performing similar missions as those of the reference ship. In a case study, we used this method as part of a ship design project, in which the functional requirements of a battery-only electric ship are defined using AIS data from a reference ship. Results indicate that the cost can be reduced by determining the functional requirements using the proposed method.
Detection of Physical Impacts of Shipping Containers during Handling Operations Using the Impact Detection Methodology
Authors: Jakovlev Sergej , Eglynas Tomas , Voznak Miroslav , Jusis Mindaugas , Partila Pavol , Tovarek Jaromir , Jankunas Valdas
Published: September 2022

The transportation of cargo inside shipping containers is a risky operation that requires constant monitoring activities and real-time operational actions. Yet, the detection of the real dynamics of the container and the surrounding infrastructure and extraction of true subsequent critical events is still an unresolved issue among engineers. In this paper, we analyze the new physical impact detection method, namely the Impact Detection Methodology (IDM), to detect the most obvious and force-dependent impacts from acceleration data, using the IoT sensor in an experimental environment using the heavy machinery of a seaport. By variating the threshold level, we have observed the changes in the number of impacts detected within three separate case studies. Results suggest that the optimal parameters tend to provide an adequate number of events, yet even the slightest change in the threshold level can increase or decrease the number of detected impacts in a non-linear fashion, making the detection harder, due to unforeseen external impacts on the dataset, the filtering of which is still the main priority of our future research.
Analysis of Characteristic Changes of Blended Very Low Sulfur Fuel Oil on Ultrasonic Frequency for Marine Fuel
Authors: Ju Hae-ji , Jeon Soo-kyung
Published: September 2022

The demand for very low sulfur fuel oil (VLSFO) with a sulfur content of less than 0.5% has increased since the IMO2020 regulations were published. However, most VLSFOs for marine fuel are produced by blending two fuel oils with different sulfur contents, which causes some problems, such as sludge formation. This study investigates the effect of ultrasonic irradiation frequency (25 and 72 kHz), ultrasonic irradiation time (0, 12, and 24 h), and the blending ratio (marine gas oil (MGO) and bunker-A (B-A) with weight ratios of 25:75, 50:50, and 75:25 on the characteristics of blended VLSFO. After 12 h of irradiation time and a frequency of 25 kHz, the amount of carbon residue decreases with increasing MGO content; it decreases by 33% for 75% MGO. However, at 72 kHz, the carbon residue increases with increasing MGO content, implying that the change in carbon residue depends on the ultrasonic frequency. After 24 h, the carbon residue does not decrease in any scenario; however, it does increase in some cases due to asphaltene reaggregation caused by excessive ultrasonic irritation. The sulfur content decreases by approximately 4% for the 100% B-A condition.
Next-Generation Sequencing of Ancient and Recent Fungarium Specimens
Authors: Miller Andrew N. , Karakehian Jason , Raudabaugh Daniel B.
Published: September 2022

Fungaria are an unmatched resource for providing genetic data from authoritative, taxonomically-correct fungal species, especially type specimens. These specimens serve to anchor species hypotheses by enabling the correct taxonomic placement of taxa in systematic studies. The DNA from ancient specimens older than 30 years is commonly fragmented, and sometimes highly contaminated by exogenous, non-target fungal DNA, making conventional PCR amplification and Sanger sequencing difficult or impossible. Here, we present the results of DNA extraction, PCR amplification of the ITS2 region, and Illumina MiSeq Nano sequencing of nine recent and 11 ancient specimens, including seven type specimens. The taxa sampled included a range of large and fleshy, to small and tough, or small, melanized specimens of Discina, Gyromitra, Propolis, Stictis, and Xerotrema, with a culture of Lasiosphaeria serving as a positive control. DNA was highly fragmented and in very low quantity for most samples, resulting in inconclusive or incorrect results for all but five samples. Taxonomically-correct sequences were generated from the holotype specimens of G. arctica, G. korshinskii, and G. leucoxantha, from the neotype of G. ussuriensis, and from the positive control. Taxonomic assignments were confirmed through morphology, top BLASTn hits, and maximum likelihood phylogenetic analyses. Though this study was not cost-effective due to the small number of samples submitted and few generating correct sequences, it did produce short DNA barcode fragments for four type specimens that are essential for their correct taxonomic placement in our ongoing systematic studies.
CNVs Associated with Different Clinical Phenotypes of Psoriasis and Anti-TNF-Induced Palmoplantar Pustulosis
Authors: Reolid Alejandra , Sahuquillo-Torralba Antonio , Sanz-García Ancor , Botella-Estrada Rafael , Muñoz-Aceituno Ester , Llamas-Velasco Mar , García-Martínez Jorge , Daudén Esteban , Abad-Santos Francisco , Ovejero-Benito María C.
Published: September 2022

Background: Psoriasis can present different phenotypes and could affect diverse body areas. In contrast to the high effectiveness of biological drugs in the treatment of trunk and extremities plaque psoriasis, in palmoplantar phenotypes and in plaque scalp psoriasis, these same drugs usually have reduced efficacy. Anti-TNF drugs could induce the appearance of palmoplantar pustulosis (PPP) in patients with other inflammatory diseases. The objective of this study is to identify if there are DNA Copy Number Variations (CNVs) associated with these different clinical phenotypes, which could justify the differences found in clinical practice. Moreover, we intend to elucidate if anti-TNF-induced PPP has a similar genetic background to idiopathic PPP. Methods: Skin samples were collected from 39 patients with different patterns of psoriasis and six patients with anti-TNF-induced PPP. The CNVs were obtained from methylation array data (Illumina Infinium Human Methylation) using the conumee R package. Results: No significant CNVs were found between the different phenotypes and the locations of psoriasis compared. Nevertheless, we found two significant bins harboring five different genes associated with anti-TNF-induced PPP in patients with a different background other than psoriasis. Conclusions: Our results may help to predict which patients could develop anti-TNF-induced PPP.
A Two-Step Approach for 3D-Guided Patient-Specific Corrective Limb Osteotomies
Authors: Assink Nick , Meesters Anne M. L. , ten Duis Kaj , Harbers Jorrit S. , IJpma Frank F. A. , van der Veen Hugo C. , Doornberg Job N. , Pijpker Peter A. J. , Kraeima Joep
Published: September 2022

Background: Corrective osteotomy surgery for long bone anomalies can be very challenging since deformation of the bone is often present in three dimensions. We developed a two-step approach for 3D-planned corrective osteotomies which consists of a cutting and reposition guide in combination with a conventional osteosynthesis plate. This study aimed to assess accuracy of the achieved corrections using this two-step technique. Methods: All patients (≥12 years) treated for post-traumatic malunion with a two-step 3D-planned corrective osteotomy within our center in 2021 were prospectively included. Three-dimensional virtual models of the planned outcome and the clinically achieved outcome were obtained and aligned. Postoperative evaluation of the accuracy of performed corrections was assessed by measuring the preoperative and postoperative alignment error in terms of angulation, rotation and translation. Results: A total of 10 patients were included. All corrective osteotomies were performed according to the predetermined surgical plan without any complications. The preoperative deformities ranged from 7.1 to 27.5° in terms of angulation and 5.3 to 26.1° in terms of rotation. The achieved alignment deviated on average 2.1 ± 1.0 and 3.4 ± 1.6 degrees from the planning for the angulation and rotation, respectively. Conclusions: A two-step approach for 3D-guided patient-specific corrective limb osteotomies is reliable, feasible and accurate.
Gastrointestinal Tract Polyp Anomaly Segmentation on Colonoscopy Images Using Graft-U-Net
Authors: Ramzan Muhammad , Raza Mudassar , Sharif Muhammad Imran , Kadry Seifedine
Published: September 2022

Computer-aided polyp segmentation is a crucial task that supports gastroenterologists in examining and resecting anomalous tissue in the gastrointestinal tract. The disease polyps grow mainly in the colorectal area of the gastrointestinal tract and in the mucous membrane, which has protrusions of micro-abnormal tissue that increase the risk of incurable diseases such as cancer. So, the early examination of polyps can decrease the chance of the polyps growing into cancer, such as adenomas, which can change into cancer. Deep learning-based diagnostic systems play a vital role in diagnosing diseases in the early stages. A deep learning method, Graft-U-Net, is proposed to segment polyps using colonoscopy frames. Graft-U-Net is a modified version of UNet, which comprises three stages, including the preprocessing, encoder, and decoder stages. The preprocessing technique is used to improve the contrast of the colonoscopy frames. Graft-U-Net comprises encoder and decoder blocks where the encoder analyzes features, while the decoder performs the features’ synthesizing processes. The Graft-U-Net model offers better segmentation results than existing deep learning models. The experiments were conducted using two open-access datasets, Kvasir-SEG and CVC-ClinicDB. The datasets were prepared from the large bowel of the gastrointestinal tract by performing a colonoscopy procedure. The anticipated model outperforms in terms of its mean Dice of 96.61% and mean Intersection over Union (mIoU) of 82.45% with the Kvasir-SEG dataset. Similarly, with the CVC-ClinicDB dataset, the method achieved a mean Dice of 89.95% and an mIoU of 81.38%.
Quantitative Three-Dimensional Measurements of Acetabular Fracture Displacement Could Be Predictive for Native Hip Survivorship
Authors: Meesters Anne M. L. , Oldhoff Miriam G. E. , Trouwborst Neeltje M. , Assink Nick , Kraeima Joep , Witjes Max J. H. , de Vries Jean-Paul P. M. , ten Duis Kaj , IJpma Frank F. A.
Published: September 2022

This study aims to develop a three-dimensional (3D) measurement for acetabular fracture displacement, determine the inter- and intra-observer variability, and correlate the measurement with clinical outcome. Three-dimensional models were created for 100 patients surgically treated for acetabular fractures. The ‘3D gap area’, the 3D surface between all the fracture fragments, was developed. The association between the 3D gap area and the risk of conversion to a total hip arthroplasty (THA) was determined by an ROC curve and a Cox regression analysis. The 3D gap area had an excellent inter-observer and intra-observer reliability. The preoperative median 3D gap area for patients without and with a THA was 1731 mm2 versus 2237 mm2. The median postoperative 3D gap area was 640 mm2 versus 845 mm2. The area under the curve was 0.63. The Cox regression analysis showed that a preoperative 3D gap area > 2103 mm2 and a postoperative 3D gap area > 1058 mm2 were independently associated with a 3.0 versus 2.4 times higher risk of conversion to a THA. A 3D assessment of acetabular fractures is feasible, reproducible, and correlates with clinical outcome. Three-dimensional measurements could be added to the current classification systems to quantify the level of fracture displacement and to assess operative results.
The Caliber of Segmental and Subsegmental Vessels in COVID-19 Pneumonia Is Enlarged: A Distinctive Feature in Comparison with Other Forms of Inflammatory and Thromboembolic Diseases
Authors: Ambrosetti Maria-Chiara , Battocchio Giulia , Montemezzi Stefania , Cattazzo Filippo , Bejko Tissjana , Tacconelli Evelina , Minuz Pietro , Crisafulli Ernesto , Fava Cristiano , Mansueto Giancarlo
Published: September 2022

Background: The purpose of this study was to compare COVID-19 patients’ vessel caliber with that of normal lungs and lungs affected by other inflammatory and thromboembolic processes. Methods: between March and April 2020, 42 patients affected by COVID-19 pneumonia (COV-P) underwent CT scans of the lungs at Verona University Hospital for clinical indications. The lung images of four different groups of patients were compared (normal lung (NL), distal thromboembolism (DTE), and bacterial and fungal pneumonia (Bact-P, Fung-P)) by a radiologist with four years of experience. Results: The COV-P patients’ segmental and subsegmental vessels, evaluated as the ratio with the corresponding bronchial branch (V/B ratio), were larger, with respect to the NL the DTE groups, in the apparently healthy parenchyma, a result confirmed in the zones of opacification with respect to the Bact-P and Fung-P groups. Conclusions: This was the first study to show, by comparative analysis, that COVID-19 patients’ segmental and subsegmental vessel calibers are significantly enlarged. This is a distinctive feature of COVID-19 pneumonia, suggesting its distinct pathophysiology as compared to other inflammatory and thromboembolic diseases and alerting radiologists to consider it when evaluating the CT scans of suspected patients.
Corrected Allele Frequency of BRCA1/2 Mutations Is an Independent Prognostic Factor for Treatment Response to PARP-Inhibitors in Ovarian Cancer Patients
Authors: Grech Christina T. , Pils Dietmar , Aust Stefanie , Grimm Christoph , Polterauer Stephan , Reinthaller Alexander , Müllauer Leonhard , Reischer Theresa , Bekos Christine
Published: September 2022

PARP inhibitors (PARPi) have increased treatment options in ovarian cancer, particularly in patients with BRCA1/2 mutations, although there are still marked differences in the duration of patients’ response to this targeted therapy. BRCA testing is routinely performed in tumor tissue of ovarian cancer patients. The resulting molecular pathological findings include the genetic nomenclature of the mutation, the frequency of the mutated allele (variant allele frequency, VAF), and the tumor cell content. VAF measures the percentage of mutated alleles from the total alleles in the cells of the examined tissue. The aim of this study was to investigate the significance of VAF on the therapeutic response to PARPis in ovarian cancer patients. Epithelial ovarian cancer patients harboring BRCA1/2 tumor mutations, who underwent germline testing and received PARPi therapy at the Medical University of Vienna (n = 41) were included in the study. Corrected VAF (cVAF) was calculated based on VAF, tumor cell content, and germline mutation. Patients were divided into two groups based on their cVAF. Median PFS under PARPi in patients with low cVAF was 13.0 months (IQR [10.3-not reached]) and was not reached in the high cVAF group. High cVAF was significantly associated with longer PFS in the multivariate analysis (HR = 0.07; 95% CI [0.01–0.63]; p = 0.017). In conclusion, high cVAF was associated with a significantly better response to PARPi in this study population.
Mathematical Model of Interaction of Therapist and Patients with Bipolar Disorder: A Systematic Literature Review
Authors: Nursuprianah Indah , Anggriani Nursanti , Nuraini Nuning , Rosandi Yudi
Published: September 2022

Mood swings in patients with bipolar disorder (BD) are difficult to control and can lead to self-harm and suicide. The interaction between the therapist and BD will determine the success of therapy. The interaction model between the therapist and BD begins by reviewing the models that were previously developed using the Systematic Literature Review and Bibliometric methods. The limit of articles used was sourced from the Science Direct, Google Scholar, and Dimensions databases from 2009 to 2022. The results obtained were 67 articles out of a total of 382 articles, which were then re-selected. The results of the selection of the last articles reviewed were 52 articles. Using VOSviewer version 1.6.16, a visualization of the relationship between the quotes “model”, “therapy”, “emotions”, and “bipolar disorder” can be seen. This study also discusses the types of therapy that can be used by BD, as well as treatment innovations and the mathematical model of the therapy itself. The results of this study are expected to help further researchers to develop an interaction model between therapists and BD to improve the quality of life of BD.
Moderate COVID-19: Clinical Trajectories and Predictors of Progression and Outcomes
Authors: Pappas Apostolos G. , Panagopoulos Andreas , Rodopoulou Artemis , Alexandrou Michaella , Chaliasou Anna-Louiza , Skianis Konstantinos , Kranidioti Eleftheria , Chaini Eleftheria , Papanikolaou Ilias , Kalomenidis Ioannis
Published: September 2022

Background: Patients with COVID-19 commonly present at healthcare facilities with moderate disease, i.e., pneumonia without a need for oxygen therapy. Aim: To identify clinical/laboratory characteristics of patients with moderate COVID-19, which could predict disease progression. Methods: 384 adult patients presented with moderate COVID-19 and admitted to two hospitals were retrospectively evaluated. In a multivariate analysis gender, age, BMI, Charlson Comorbidity Index (CCI) and National Early Weaning Score 2 were treated as co-variates. The development of hypoxemic respiratory failure, intubation rate and risk of death were considered as dependent variables. Estimated values are presented as odds-ratio (OR) with 95% confidence interval (CI). Results: Most of the patients were male (63.28%) with a mean (standard deviation) age of 59 (16.04) years. Median (interquartile range) CCI was 2 (1–4). A total of 58.85% of the patients developed respiratory failure; 6.51% were intubated, and 8.85% died. The extent of pneumonia in chest X-ray (involvement of all four quartiles) [OR 3.96 (1.18–13.27), p = 0.026], respiratory rate [OR 1.17 (1.05–1.3), p = 0.004], SatO2 [OR 0.72 (0.58–0.88), p = 0.002], systolic blood pressure [OR 1.02 (1–1.04), p = 0.041] and lymphocyte count [OR 0.9993 (0.9986–0.9999), p = 0.026] at presentation were associated with the development of respiratory failure. The extent of pneumonia [OR 26.49 (1.81–387.18), p = 0.017] was associated with intubation risk. Age [OR 1.14 (1.03–1.26), p = 0.014] and the extent of pneumonia [OR 22.47 (1.59–316.97), p = 0.021] were associated with increased risk of death. Conclusion: Older age, the extent of pneumonia, tachypnea, lower SatO2, higher systolic blood pressure and lymphopenia are associated with dismal outcomes in patients presenting with moderate COVID-19.
Saddlepoint Method for Pricing European Options under Markov-Switching Heston’s Stochastic Volatility Model
Authors: Zhang Mengzhe , Chan Leunglung
Published: September 2022

This paper evaluates the prices of European-style options when dynamics of the underlying asset is assumed to follow a Markov-switching Heston’s stochastic volatility model. Under this framework, the expected return and the long-term mean of the variance of the underlying asset rely on states of the economy modeled by a continuous-time Markov chain. There is evidence that the Markov-switching Heston’s stochastic volatility model performs well in capturing major events affecting price dynamics. However, due to the nature of the model, analytic solutions for the prices of options or other financial derivatives do not exist. By means of the saddlepoint method, an analytic approximation for European-style option price is presented. The saddlepoint method gives an effective approximation to option prices under the Markov-switching Heston’s stochastic volatility model.
Eliciting Herders’ Willingness to Accept Grassland Conservation: A Choice Experiment Design in Pastoral Regions of China
Authors: Lv Xinxin , Zhang Mingxue , Li Dongqing
Published: September 2022

Top-down grassland conservation policies are widely used to protect grassland ecosystems from degradation in developing counties. However, an inability to meet local herders’ preferences when implementing such ecological policies may weaken their outcomes. Using a choice experiment design, this paper evaluated herders’ willingness to accept (WTA) different possible implementations of a grazing ban policy, which is an ongoing but inflexible grassland protection policy in China. The results showed that herders were more likely to accept a grazing ban policy that targets private benefits rather than public benefits. In particular, herder’s WTA decreased when the policy objective changed from improving private grassland productivity to protecting grassland wildlife (or preventing sandstorms). Additionally, broader coverage and a longer duration also increased herders’ WTA a grazing ban policy; i.e., herders preferred a grazing ban policy with less coverage and a shorter duration. Our heterogeneity analysis showed that herder’s WTA is not only associated with their socioeconomic characteristics, but also with their altruism. Herders with higher altruistic tendencies were more willing to engage in a gazing ban policy targeting public benefits. These findings offer valuable insight into potential methods of redesigning top-down grassland protection policies and incentivizing small herders to adapt to environmentally friendly practices in China or other countries with similar backgrounds.
Impact of Long-Term Nutrient Supply Options on Soil Aggregate Stability after Nineteen Years of Rice–Wheat Cropping System
Authors: Meena Sunita Kumari , Dwivedi Brahma Swaroop , Meena Mahesh Chand , Datta Saba Prasad , Singh Vinod Kumar , Mishra Rajendra Prasad , Chakraborty Debashish , Dey Abir , Meena Vijay Singh
Published: September 2022

Continuing soil degradation remains a serious threat to future food security. Soil aggregation can help protect soil organic matter from biodegradation; it affects soil physical (aeration), chemical (water infiltration), and biological (microbial) activities. The integrated plant nutrition system (IPNS) and organic farming (OF) options have been contemplated as a sustainable strategy to sustain soil aggregate stability under adverse climatic conditions and a possible tool to restore degraded soil systems. Results suggested that the application of plant nutrients based on IPNS and soil test crop response (STCR) including mineral fertilizers and organic manure (farmyard manure: FYM) improved soil aggregate stability and mean weight diameter (MWD) under rice–wheat cropping systems. A long-term (19 year) cropping system (rice–wheat) experiment was examined to identify best nutrient management practices. Seven nutrient supply options were applied: organic, mineral fertilizer in combination with IPNS, IPNS + B/IPNS + C to improve soil aggregate stability and MWD after completing 19 cropping cycles of rice–wheat cropping systems. Results showed that significantly higher (+31%) macroaggregates were dominant in the surface soil layer than in the subsurface soil. The significantly highest macroaggregates were observed under OF (60.12 g 100 g−1 dry soil) management practices followed by IPNS options. The MWD was significantly increased (+17%) between surface and subsurface soil. Maximum MWD was reported with OF (0.93 mm) management practices followed by the IPNS + C (0.78 mm), IPNS + B (0.77 mm), IPNS (0.70 mm), STCR (0.69 mm), NPK (0.67 mm), and unfertilized control (0.66 mm) plots. Overall, results suggest that the adoption of IPNS options, such as organic farming (OF), RDF, STCR, and inclusion of pulses (berseem and cowpea), significantly improved all soil aggregation fractions in the soil system and also offered an additional benefit in terms of soil sustainability.
Changing Perceptions and Uses of “Companion Animal” Public and Pseudo-Public Spaces in Cities during COVID-19 Pandemic: The Case of Beijing
Authors: Cai Haoxian , Duan Wei
Published: September 2022

This paper examines the debate over the place of “companion animal” public space in China’s cities. With the COVID-19 outbreak, this debate has entered a new phase, where the social response to the outbreak may have fundamentally changed the public’s use and perception of “companion animal” public and pseudo-public space. This paper combines quantitative and qualitative analysis of posts and comments on two of China’s largest social media platforms with a big data approach, based on a case study in Beijing, China. There were statistically significant differences in the perception and use of “companion animal” public spaces and pseudo-public spaces before and after the pandemic. We attribute the impact of the pandemic on “companion animal” spaces to three pathways: changes in opportunity, changes in ability, and changes in motivation. We found that the pandemic led to an increase in the amount of time available to some people but a decrease in the amount of “companion animal” public space available due to the pandemic closure. In addition, the use of “companion animal” public spaces in pseudo-public spaces declined, while those located within the open urban green space on the city’s outskirts stood out after the outbreak. With the normalisation of the pandemic, there will be new challenges for the development and operation of companion-animal-related public spaces in cities, which will be the next focus of research. In addition, governments and social media should work together to promote and support sustainable animal ethical practices to better respond to the crisis. These findings will help complement the urban services system and guide future planning, design, and evaluation of related spaces.
Spatio-Temporal Characteristics and Influencing Factors of Basic Public Service Levels in the Yangtze River Delta Region, China
Authors: Li Tianyu , Zhao Yizheng , Kong Xiang
Published: September 2022

Basic public services are essential to ensure regional social equity and promote regional integrated development. As the Yangtze River Delta region (YRDR) is an example of integrated regional development in China, the integration of basic public services plays a crucial role in promoting regions’ integrated development. However, little studies provide evidence of the characteristics and influencing factors of basic public services in the YRDR. Taking the YRDR as the study area, this paper constructed a comprehensive evaluation index system for the basic public services level (BPSL) in the YRDR from 2010 to 2020. Then, it measured and analyzed its spatio-temporal dynamic evolution characteristics using entropy-weighted TOPSIS and exploratory spatial data analysis methods, as well as analyzed the spatio-temporal heterogeneity of its influencing factors using a geographically and temporally weighted regression model. The results show that: (1) The BPSL in the YRDR generally improved during the study period. There was a huge variation within and between provinces in the BPSL. Over time, the BPSL gradually transitions from unipolar polarization to multipolar differentiation and a flattening trend. (2) Spatial differentiation of the BPSL was evident, with a decreasing gradient from east to west with an inverted U-shape distribution in the north–south direction. The overall spatial circle structure was characterized as being high in the east and low in the west, high in the center, and low in the north and south, forming a spatial distribution pattern of high-level and higher-level grades mainly in Shanghai, southern Jiangsu, and northern Zhejiang. The global spatial correlation characteristics became increasingly significant with time, while the local spatial correlation showed the trend of “spatial club convergence”. (3) Various factors influenced the spatial and temporal evolution of the BPSL, including the urbanization level, the economic development level, the industrial structure level, the degree of external openness, the government action capacity, and the regional population size, each of which had evident spatial and temporal heterogeneity.
Mapping the Risk of COVID-19 Contagion at Urban Scale
Authors: Sortino Barrionuevo Juan Francisco , Castro Noblejas Hugo , Perles Roselló María Jesús
Published: September 2022

From the beginning of the COVID-19 pandemic, several methods have been developed to assess the risk of COVID-19 transmission using spatial units of analysis based on administrative limits (e.g., neighborhoods, census sections, and districts). The main objective of this study is to create a method to assess the risk of contagion within an interurban scale, considering buildings as the smallest unit of analysis. The general risk equation has been the basis to develop the method, individually assessing its components (i.e., hazard, vulnerability, and exposure). Several mapping tools that address the management of the risk of contagion have been proposed, and the main result was the detection of a pattern of contagion and the identification of areas where the risk of contagion was greater. Additionally, the comparison of the risk of a contagion pattern and the population size at an intraurban scale allowed for inferring the specific vulnerability of the population to contagion. The results also showed that there was a direct relation between the risk of contagion and population density, as well as the presence of areas especially vulnerable to contagion.
Scenario Analysis for Resilient Urban Green Infrastructure
Authors: Li Bo , Wang Yue , Wang Tong , He Xiaoman , Kazak Jan K.
Published: September 2022

With the advancement of urbanization, the stress on the green infrastructure around the urban agglomeration has intensified, which causes severe ecological problems. The uncertainty of urban growth makes it difficult to achieve effective protection only by setting protection red lines and other rigid measures. It is of practical significance to optimize the resilience of the stressed green infrastructure. To this end, we explore a scenario simulation analysis method for the resilience management of green infrastructure under stress. This research applies artificial neural network cellular automata to simulate the impacts of the Chang-Zhu-Tan urban agglomeration expansion on the green infrastructure in 2030 in three scenarios: no planning control, urban planning control, and ecological protection planning control. Based on the analysis, we identify four green infrastructure areas under stress and formulate resilience management measures, respectively. The results show that: (1) The distribution pattern of green infrastructure under stress is different in three scenarios. Even in the scenario of ecological protection planning and control, urban growth can easily break through the ecological protection boundary; (2) Residential, industrial, and traffic facility land are the main types of urban land causing green infrastructure stress, while forest, shrub, and wetland are the main types of the stressed green infrastructure; (3) Efficient protection of green infrastructure and the management of the urban growth boundary should be promoted by resilient management measures such as urban planning adjustment, regulatory detailed planning, development strength control and setting up the ecological protection facilities for the stressed green infrastructure areas of the planning scenarios and the no-planning control scenarios, for the areas to be occupied by urban land, and for the important ecological corridors. The results of this study provide an empirical foundation for formulating policies and the methods of this study can be applied to urban ecological planning and green infrastructure management practice in other areas as well.
Restored and Natural Wetland Small Mammal Communities in West Virginia, USA
Authors: Noe Krista L. , Rota Christopher T. , Frantz Mack W. , Anderson James T.
Published: September 2022

Wetland restoration is a common practice, and, in many cases, it is for mitigation to offset losses of natural wetlands due to human interference. Researchers commonly compare bird, amphibian, and reptile communities between these wetlands and natural wetlands but overlook small mammals. However, terrestrial small mammals are essential to consider as they serve a fundamental role in the ecosystem as seed dispersers and prey for larger wildlife. We conducted small mammal trapping on 26 wetlands (n = 14 restored, n = 12 natural) in West Virginia, USA, in the summers of 2020 and 2021 to obtain and compare community metrics between wetland types. We found that mass, occupancy probability, and community composition were similar between restored and natural wetlands. However, the apparent abundance of deer mice (Peromyscus maniculatus) was higher in natural wetlands (p < 0.001). Because we captured the three rarest species exclusively in natural wetlands, the ability of restored wetlands to provide an adequate habitat for rare or wetland-obligate species may be biologically significant. Restored wetlands mainly offer sufficient habitat for small mammal communities, but apparent abundance in restored wetlands may differ from natural wetlands depending on species.
Effects of the Talent War on Urban Innovation in China: A Difference-in-Differences Analysis
Authors: Shi Xiaoli , Chen Ying , Xia Menghan , Zhang Yongli
Published: September 2022

Talent is an important strategic resource for regional economic development. Based on the background of “the talent war” that has broken out between various cities in recent years, this study empirically verified the influence of the talent policy on urban innovation in 277 prefecture-level cities in China from 2010 to 2019 using the multi-period difference-in-differences model. The results indicated that “the talent war” caused by the talent policy has positively influenced urban innovation, causing, for instance, a dramatic increase in the number of patents for inventions. Among the subsidy methods of “the talent war” policy, the employment and entrepreneurship subsidy had the greatest incentive effect on urban innovation, followed by the talent housing subsidy. Moreover, the “the talent war” policy exerted a positive impact on urban innovation by improving the innovation willingness of cities and the level of talent gathering. At present, “the talent war” cities have, to a certain extent, restrained the improvement of urban innovation in neighboring cities because of the siphon effect, resulting in the division of the regional labor market. A heterogeneity analysis showed that “the talent war” has significantly promoted substantive innovation and the development of coastal cities with a better business environment and a higher degree of intellectual property protection.
Assessment on the Spatial Distribution Suitability of Ethnic Minority Villages in Fujian Province Based on GeoDetector and AHP Method
Authors: Xu Xiang , Genovese Paolo Vincenzo
Published: September 2022

Ethnic minority villages are important resources for the economy and social development of ethnic minority areas because they preserve ethnic minorities’ culture. With the rapid development of industrialization and urbanization in China, the factors affecting the development of villages have changed. With the help and guidance of the government, the gap between villages has increased. According to the development conditions of ethnic minority villages at the present stage, the suitability of their spatial distribution has been studied, the existing problems in the current development have been explored, and the development laws and future development trends have been found. To make the evaluation results more scientific and objective, Geographical Detector (Geodetector) and Absorbent Hygiene Product (AHP) methods are used to establish the evaluation model. Taking 567 ethnic minority villages in Fujian Province as the research object, 13 factors are selected from the aspects of natural geographical, socio-economy and cultural life to construct the evaluation indicator system of Fujian ethnic minority villages, and the spatial distribution suitability of Fujian ethnic minority villages is quantitatively evaluated. The findings indicated the following: (1) The per capita income of villages has the most important impact on the suitability of spatial distribution of Fujian minority villages. Through comprehensive evaluation, the impact of cultural life indicators on the suitability of the spatial distribution of the village is greater than that of socio-economic indicators and natural geographical indicators. The intensity relationship is 9:7:10. (2) The high suitability value is concentrated in Fujian Province’s southeast coastal and central areas, gradually decreasing from east to west. In Fujian Province, 82.84%of the land is suitable for the development of ethnic minority villages, with 89% of ethnic minority villages. The unsuitable areas are mostly in Fujian’s north and west. (3) The most suitable cities for the number of ethnic minority villages are Ningde City and Quanzhou City because ethnic minority villages in these two cities are mostly distributed in areas relatively close to the central urban area, with good economic conditions, flat terrain, and easy transportation. The cities of Nanping and Sanming are the least suitable for many ethnic minority villages, which are primarily limited by topographic conditions, have a backward economy, a sparse road network, and have experienced significant population loss. In the context of urbanization, the evaluation results can provide a reference for the precise development and protection of minority villages. Governments at all levels in Fujian Province can adjust and optimize the development strategies of minority villages according to the evaluation results.