Boundary Line Research Articles

Harnessing Smectic Ordering for Electric-Field-Driven Guided-Growth of Surface Topography in a Liquid Crystal Polymer.

The guided-growth strategy has been widely explored and proved its efficacy in fabricating surface micro/nanostructures in a variety of systems. However, soft materials like polymers are much less investigated partly due to the lack of strong internal driving mechanisms. Herein, the possibility of utilizing liquid crystal (LC) ordering of smectic liquid crystal polymers (LCPs) to induce guided growth of surface topography during the formation of electrohydrodynamic (EHD) patterns is demonstrated. In a two-stage growth, regular stripes are first found to selectively emerge from the homogeneously aligned region of an initially flat LCP film, and then extend neatly along the normal direction of the boundary line between homogeneous and homeotropic alignments. The stripes can maintain their directions for quite a distance before deviating. Coupled with the advanced tools for controlling LC alignment, intricate surface topographies can be produced in LCP films starting from relatively simple designs. The regularity of grown pattern is determined by the LC ordering of the polymer material, and influenced by conditions of EHD growth. The proposed approach provides new opportunities to employ LCPs in optical and electrical applications.

Government innovation preferences, institutional fragility, and digital economic development

Institutional fragility is an important factor influencing government innovation preferences and driving the development of the digital economy. This study incorporates institutional fragility into the effectiveness of government innovation preferences in driving the digital economy's development. Based on panel data from 30 provinces and regions in China from 2013 to 2021, a "vertical-horizontal" hierarchy method is used to assess the level of digital economic development. A fixed-effects model is applied to examine the impact and transmission mechanism of government innovation preferences on the digital economy. The study also analyzes the moderating effect of institutional fragility and threshold effects. The results are as follows: (1) Digital economic development exhibits an "East high-West low" development pattern, with the boundary line becoming more distinct over time. (2) Government innovation preferences significantly positively influence digital economic development, with a more pronounced effect in the western regions. Overall, a 1 % increase in government innovation preferences results in an average 2.041 % increase in digital economic development, with regional innovation capacity playing a partial mediating role. (3) Institutional fragility negatively moderates the effect of government innovation preferences on the digital economy, and there is a dual-threshold effect. As institutional fragility eases, the driving force of government innovation preferences shows a stepwise upward trend.

Splitting of Solutions of Weakly Nonlinear Singularly Perturbed Equations Under Regular Degeneration

We consider a weakly nonlinear singularly perturbed equation in complex domains. The problem is posed about the possibility of splitting the equation into several components. By introducing new unknown functions, a system of two equations is obtained. Next, the asymptotic behavior of solutions of the resulting equations in complex domains is studied. It has been proven that the solution to each of these equations is dominant in certain parts of the areas under consideration. The solution of one of these equations determines the boundary lines and regions, and the solution of the other system determines the regular region.

A Logic Threshold Control Strategy to Improve the Regenerative Braking Energy Recovery of Electric Vehicles

With increasing global attention to climate change and environmental sustainability, the sustainable development of the automotive industry has become an important issue. This study focuses on the regenerative braking issues in pure electric vehicles. Specifically, it intends to elucidate the influence of the braking force distribution of the front and rear axles on access to energy recovery efficiency. Combining the I curve of a pure electric vehicle and the boundary line of the Economic Commission of Europe (ECE) regulations, the braking force distribution relationship between the front and rear axles is formulated to satisfy braking stability. The maximum regenerative braking force of the motor is determined based on the motor torque characteristics and battery charging power, and the regenerative braking torque is optimized by combining the constraints of the braking strength, battery state of charge (SOC), and vehicle speed. Six road working conditions are built, including the New European Driving Cycle (NEDC), the World Light-Duty Vehicle Test Cycle (WLTC), Federal Test Procedure 72 (FTP-72), Federal Test Procedure 75 (FTP-75), the China Light-Duty Vehicle Test Cycle—Passenger (CLTC-P), and the New York City Cycle (NYCC). The efficiency of the regenerative braking strategy is validated by using the Simulink/MATLAB simulation. The simulation results show that the proposed dynamic logic threshold control strategy can significantly improve the energy recovery effect of electric vehicles, and the energy recovery efficiency can be improved by at least 25% compared to the situation without regenerative braking. Specifically, under the aforementioned road working conditions, the braking energy recovery efficiency levels are 27.69%, 42.18%, 49.54%, 47.60%, 49.28%, and 51.06%, respectively. Moreover, the energy recovery efficiency obtained by the current dynamic logic threshold is also compared with other published results. The regenerative braking control method proposed in this article makes the braking control of electric vehicles more precise, effectively reducing energy consumption and improving the driving range of electric vehicles.

Addressing food insecurity: An exploration of wheat production expansion

Wheat plays a crucial role in global food security, serving as a vital food crop that feeds billions of people worldwide. Currently, Russia and Ukraine are responsible for exporting approximately 25% of the world’s wheat, making any issues in these regions a cause for concern regarding global wheat supply. The problems faced in these areas have led to a surge in wheat prices worldwide. Consequently, it becomes necessary to explore alternative regions that can compensate for the decline in wheat production and supply. This study focuses on wheat production and yield in major producing countries, utilizing the GYGA (Global Yield Gap Atlas) protocol for predictions. The findings reveal a global wheat production gap of 270,378,793 tons. Notably, the largest gap in irrigated wheat production exists in countries like China, India, Pakistan, Turkey, Iran, Afghanistan, Uzbekistan, Egypt, and Azerbaijan. Additionally, the rainfed wheat production gap on a global scale amounts to 545,215,692 tons, with Russia, the USA, Kazakhstan, Australia, Ukraine, China, Turkey, Canada, India, and France having the most significant production gaps. Through boundary line analysis, specific criteria were identified for suitable areas of irrigated and rainfed wheat cultivation. For irrigated conditions, the temperature range of 3000 to 7000 GDD (Growing Degree Days) and a temperature seasonality of 3 were determined as favorable. Under rainfed conditions, the suitable areas encompass a temperature range of 2000 to 4000 GDD, an aridity index exceeding 600, and a temperature seasonality of 2. Thirteen countries possess extensive agricultural land within the climatic codes favorable for irrigated wheat cultivation. Approximately 50% of the agricultural lands within these countries, corresponding to the total arable area for irrigated wheat, fall within the climatic codes 3403, 5403, 5303, 4303, 5503, 5203, 3503, 3303, and 4103. China, the United States, Ukraine, Russia, and Iran are the top five countries with favorable lands for irrigated wheat cultivation. Similarly, fourteen countries have significant agricultural lands within the favorable climatic codes for rainfed wheat cultivation. Around 52% of the agricultural lands within these countries are within the climatic codes 3702, 2702, 2802, and 4602. France, Germany, Britain, Poland, and Denmark possess the highest potential to expand rainfed wheat cultivation areas within these favorable climate codes, with respective areas of 2.7, 2.6, 1.6, and 0.9 million hectares. According to the study, the North China Plain emerges as a primary region for increasing irrigated wheat production, both in terms of cultivated area and yield potential. For rainfed conditions, the European continent stands out as a significant region to enhance wheat production.

Determining optimal bead central angle by applying machine learning to wire arc additive manufacturing (WAAM)

Wire arc additive manufacturing (WAAM) is being extensively used in various industrial fields. In WAAM, if a bead is deposited without considering the central angle, its shape may collapse with increasing number of layers. To address this problem, a new method for optimizing the bead geometry using a support vector machine (SVM) classifier was established in this study. The ranges of the optimal deposition conditions were determined using the SVM classifier and verified by experiments. Geometric data of deposited beads were extracted using a laser profiler, and an SVM binary classifier was used to predict suitable ranges of the deposition conditions. Data were extracted through 20 single-layer basic experiments, classification was performed based on 4°, and the appropriateness of SVM classification was found through 8 single-layer and 3 multi-layer verification experiments.The results showed that the SVM classifier successfully selected the ranges of the optimal deposition conditions. Verification experiments revealed that the results in all cases were appropriately classified based on the boundary of the classification line. Moreover, the SVM classifier was efficient even when a small amount of input data was available. The contribution of this study is that the developed method can help build desired bead geometries in scenarios where deposition is required in the WAAM process, such as re-manufacturing. Thus, this method can be used in real-world industrial applications through further research on the bead shape with multi-layer deposition.

Convolution Power Ratio Based on Single-Ended Protection Scheme for HVDC Transmission Lines

In order to solve the problems of insufficient abilities to withstand transition resistance under remote faults and difficulties in identifying internal and external faults for HVDC transmission line protection, a new single-ended protection scheme based on time-domain convolutional power was proposed. In this scheme, the ratio of time-domain convolution power at different frequencies is used to detect internal and external faults, and the long window convolution power is used to form the pole selection criteria. Due to the integration of transient power fault characteristics at high and low frequencies, this scheme amplifies the characteristic differences between internal and external faults caused by DC line boundaries and has a strong ability to withstand transition resistance. Based on PSCAD/EMTDC, simulation verification was conducted on the Yunnan–Guangzhou ±800 kV HVDC project. The results show that the proposed single-ended protection scheme can effectively identify fault poles, as well as internal and external faults. It has strong resistance to transition resistance and certain anti-interference ability and has strong adaptability to DC line boundaries, which meets the protection requirements of HVDC transmission systems for high speed, selectivity and reliability.

Coordinated cyber-physical attack on power grids based on malicious power dispatch

This paper proposes a new mode of cyber-physical attack based on injecting false commands, which poses an increasing risk to modern power systems as a typical example of Cyber-Physical Systems (CPS). Such attacks can trigger physical attacks by driving the system into vulnerable states. To address the critical issues arising from this new mode, we define an inverse-community (IC) in power flow distribution and evaluate it using inverse-modularity. To identify the most vulnerable state of the IC that represents the inherent vulnerability of the system, we employ a full malicious power dispatch problem. We also analyze an example of the proposed mode, where a partial malicious power dispatch that maximizes inverse-modularity is combined with physical attacks aimed at disconnecting vulnerable IC boundary lines, making cascading failures highly likely. To demonstrate the potential impact of this coordinated cyber-physical attack, we use the IEEE-118 and IEEE-300 bus systems for simulation. The results show the effectiveness of this attack strategy and provide a new perspective to analyze cyber-physical security issues in modern power systems.

Grammatical Number from an Ecological Perspective, Focused on the “Here-Now-I-Real”

Abstract This article shows, using the example of number agreement, that an ecological perspective with a focus on the situation of the utterance (i.e. here-now-I-real) is an effective way to understand differences in grammar among individual languages and to identify commonalities above and beyond such differences. On the surface, English and Chinese would appear to be exact opposites in terms of whether or not they conform to the rule of number agreement, while the position of Japanese would appear to be ambivalent on this question. But in fact this is not the case. Numerous languages around the world are consistent in the way number distinction is more likely to arise the higher the subject’s position on the animacy hierarchy. Chinese and Japanese are no exceptions. Leaving aside differences in individual circumstances, languages differ only in the boundary lines on the animacy hierarchy where number distinction becomes obligatory. In order to reach the above understanding, it is essential to see animacy from an ecological perspective. Furthermore, an ecological perspective is essential as a principle for explaining levels of not only animacy but also self-expressiveness, esteem, and transitivity. The prevailing view of language as separate from the situation of the utterance requires considerable revision on the subject of grammar.i

New distribution record of Hippoid crabs on Bali strait, Indonesia

Hippoidea are known as sand crabs or mole crabs. The distribution of these crabs in Indonesia is found in the Sundaland and the eastern region bounded by the Wallacea line. The purpose of this study was to determine the existence of Hippoidea’s species in Bali Strait. The crab collection was carried out in the Bali Strait during 2 weeks in May 2023. The collection of mole crab in Bomo and Blimbingsari beaches, Banyuwangi and Watu Ulo Beach Regency East Java. Sample collection was done in the morning between 6:00-10:00 am using hands pickup and fishing bait. All of the crab samples that were successfully collected were documented on the beach sand as a photo background, then preserved in 96%. Based on the morphological identification, there were 2 species of mole crab, namely Hippa adactyla (n=11) individuals, and Albunea symysta (4) individuals. The species found on the Blimbingsari beach was only H. adactyla (5). The species from Watu Ulo Beach were 2 species Hippa adactyla (n=8) individuals, and Albunea symysta (1) individuals. These results show a new distribution and record in the central part of Indonesia, especially at the boundary of the Wallacea line.

The inconsistency of land use along the 10 m river buffer of East Kalibaru, Jakarta

The East Kalibaru River extends from Depok/South Jakarta to northern Jakarta. Visually, the riverbank is crowded with settlements, even though the Ministerial Regulation of Public Works and Housing Number 28 Years 2015 has regulated the River Boundary Line, where rivers must have a 10 m wide buffer zone. This study aims to reveal the inconsistency of land use along the 10 m river buffer of East Kalibaru using a quantitative and qualitative descriptive approach using spatial data, river hydrology, and river water quality status for the analysis process. The river was categorized into three segments (upstream, midstream, and downstream). Using ArcGIS, delineation was carried out along the 10 m river buffer of East Kalibaru and then overlaid with land use data, resulting in land use type suitability. Land use suitability was evaluated by calculating the percentage of land area based on compliance with the regulations. The inconsistency of land use along the 10 m river buffer of East Kalibaru amounted to 46.25% (26.21 ha). The most significant land use inconsistency occurred in the midstream segment (68.24% or 13.23 ha), whereas the best was found in the downstream segment (26.54% or 4.36 ha). Residential and office & trade land use types dominate the inconsistency of land use. Residential areas are mainly found in the midstream segment, with an area reaching 47.42% or 9.19 ha. The government should gradually be disciplined the 46.25% inconsistent area because the river buffers must have 100% suitable land use to optimize the function of the river boundary.

Monocular Depth Estimation for Glass Walls with Context: A New Dataset and Method.

Traditional monocular depth estimation assumes that all objects are reliably visible in the RGB color domain. However, this is not always the case as more and more buildings are decorated with transparent glass walls. This problem has not been explored due to the difficulties in annotating the depth levels of glass walls, as commercial depth sensors cannot provide correct feedbacks on transparent objects. Furthermore, estimating depths from transparent glass walls requires the aids of surrounding context, which has not been considered in prior works. To cope with this problem, we introduce the first Glass Walls Depth Dataset (GW-Depth dataset). We annotate the depth levels of transparent glass walls by propagating the context depth values within neighboring flat areas, and the glass segmentation mask and instance level line segments of glass edges are also provided. On the other hand, a tailored monocular depth estimation method is proposed to fully activate the glass wall contextual understanding. First, we propose to exploit the glass structure context by incorporating the structural prior knowledge embedded in glass boundary line segment detections. Furthermore, to make our method adaptive to scenes without structure context where the glass boundary is either absent in the image or too narrow to be recognized, we propose to derive a reflection context by utilizing the depth reliable points sampled according to the variance between two depth estimations from different resolutions. High-resolution depth is thus estimated by the weighted summation of depths by those reliable points. Extensive experiments are conducted to evaluate the effectiveness of the proposed dual context design. Superior performances of our method is also demonstrated by comparing with state-of-the-art methods. We present the first feasible solution for monocular depth estimation in the presence of glass walls, which can be widely adopted in autonomous navigation.

Erratum to: Boundary line analysis and machine learning models to identify critical soil values for major crops in Guatemala

Erratum to: Boundary line analysis and machine learning models to identify critical soil values for major crops in Guatemala

Characteristics and Attribution of Spatiotemporal Changes in Qilian Mountains' Runoff Over the Past Six Decades

AbstractTibet's Qilian Mountains (QM) include critical water conservation areas and important ecological barriers, which help maintain downstream inland river oasis stability. For decades, contemporaneous climatic and cryospheric variation has severely impacted QM's hydrological processes, challenging local water resource management and sustainable development. However, due to prevalent data and methodological limitations, QM research has primarily focused on runoff change at a basin scale. Spatial distributions and temporal changes in runoff subsequently remain unclear. Based on multi‐source data and the literature, we estimated that QM's mountain outlets generate approximately 15.671 km3 in total annual runoff, exhibiting a spatially decreasing pattern from northeast to southwest. Moreover, runoff distribution and trend variation at seasonal and annual scales depend upon the river replenishment source type. Beginning in the 1950s and 1960s, eastern rain‐fed rivers experienced a downward trend while those dominated by meltwater or simultaneously fed by multiple sources in its central and western regions experienced an upward trend. As an integrated product of mixed multi‐factor effects, runoff is regulated by temperature, precipitation, and cryospheric meltwater. Moreover, the main controlling runoff factors varied seasonally under different water source concentrations. Annually, precipitation was the main driver for runoff change in the eastern region while, correspondingly, temperature was in the western region where glaciers and the snow line boundary predominant. Besides, this study highlighted that the existing literature has significant limitations in understanding interactions among different cryospheric components and hydrologic process mechanisms when exploring the reasons for runoff variations, which needs further exploration in the future.

Investigation on strength and deformation properties of lateritic clay

Lateritic clay is often used as a construction material for roads in tropical and subtropical areas. However, these materials exhibit high compressibility, high rate of creep, and susceptibility to severe cracking due to swelling and shrinkage behavior. These traits are closely linked to its hydro-mechanical and deformation properties. In this study, firstly, a boundary line between the swelling and compression deformation zone was determined based on the results of wetting tests. This boundary line is crucial for identifying the specific deformation mechanisms observed in unsaturated lateritic clays under varying water conditions. Secondly, an analysis of the relationship between pore size distribution and the soil water retention curve (SWRC) were conducted. A simple bimodal SWRC model, using the normal distribution function, was proposed. Additionally, the strength characteristics of lateritic clay were investigated over a wide suction range. It was observed that the existing strength model significantly underestimated the tested values in the medium to high suction range. To address this, a segmented strength equation was introduced based on unsaturated effective stress analysis. This approach allows enables enhanced predictions of the strength properties of lateritic clay. Altogether, these findings have greatly contributed to a better understanding of the engineering properties of lateritic clay.

Multiscale levels CO2 decouple reinforcement in China.

Decoupling economic growth from CO2 emissions is imperative for China. Meanwhile, establishing a consistent and comprehensive decoupling inventory that includes national (N), regional and provincial (RP), and city and county (CC) levels is essential for further policy formulation. This research aims to investigate the decoupling status using the "N-RP-CC" approach while considering changes in decoupling trends at the different levels. A combination of the Tapio decoupling model and cluster analysis is employed to study the decoupling's spatiotemporal characteristics and trends. The study first calculates the decoupling value for "national, 7; regions, 30; provinces, 1501 CCs" in China, 2006-2017. The results show that there continues to be an improvement in the decoupling trend at the national level. Conversely, the regional scale exhibits a more vulnerable decoupling trend compared to the national level, with weak and extended negative decoupling observed in northeastern and northern China. Moreover, provincial heterogeneities are increasingly evident, with poor decoupling statuses appearing in Jilin, Heilongjiang, Liaoning, and Xinjiang, as well as many central provinces. Additionally, although more than half of CCs exhibit weak decoupling during most years, seven different states of decoupling were also identified during the time frame. These findings further indicate that spatiotemporal heterogeneities extend beyond RP scales within CCs. Taking the Yangtze River as a boundary line reveals a severe situation in northern areas along with rapid development trends observed in southern regions. Finally, we clustered 1414 CCs based on their industrial proportions for 2017 which further highlights increasingly prominent heterogeneities that should be carefully considered. Based on these findings, policy recommendations such as spatial organization and optimization and technique investment are proposed to achieve CO2 emission decoupling under the N-RP-CC levels.

‘A square peg in a round hole’. Transgender and gender diverse youth and schooling in South Africa

There is a continuing thread of research evidence that schools acknowledge just two self-evident genders and that trans and gender diverse (TGD) youth face significant marginalisation and exclusion. Drawing on a qualitative study of educational staff and seven TGD school-attending youth in South Africa, this paper explores two lines of inquiry – how schools as cultural and social spaces produce and resist cisnormativity and how TGD school-attending youth orientate themselves in or out of line with normative power? Shedding light on how orientation marks out boundary lines and practices of differentiation, the analysis highlights how schools produce a field of objects that ensures that schooling is orientated around the cisnormative body. The paper argues that schooling is a space where TGD youth learn their place, which is exclusion and marginalisation. The findings point to the need for urgent school reform, highlighting the need for important intervention paths to address gender diversity and schooling.

Length‐weight Relationships of Four Indigenous Freshwater Fishes of Longshen Stream, Indo-Myanmar Borderline of North-East of India

Length-weight relationships (LWR) are reported for four indigenous fish species of longshen stream, Indo-Myanmar boundary line North-Eastern Ghats of Indian region, for the period of June 2020 to September 2022. Specimen species were collected during different exploratory surveys, using through traditional bamboo made fishing gears. The b value for LWRs varied from 2.09(Barilius vagra) to 2.63(Garra lissorhynchus). R2 values varied from 0.85 to 0.95, indicating unique values. The results providing baseline information for the need of sustainable ecological as well as economical management and conservation of indigenous fish species in Indo-Myanmar borderlines

Detecting the Legacies of Climatic Extremes through Radial Growth Releases in Pinus kesiya Royle ex Gordon in Shillong, Meghalaya, Northeast India

Tree ring width index (TRWI) of Khasi pine (Pinus kesiya Royle ex Gordon) was developed from Motinagar area of Shillong, Meghalaya, Northeast India, encompassing 124 years of data spanning from 1896 to 2019. The descriptive statistics (e.g., series-intercorrelation, 0.338, mean sensitivity, 0.177, standard deviation, 0.170, signal-to-noise ratio, 6.037) of TRWI indicate the significant potential of the species for dendroclimatology in the region. Moreover, the growth release detection analysis carried out using the radial-growth averaging (GA), the boundary-line (BL), and the Splechtna (SP) methods showed a large number of growth releases, with moderate growth releases of 24%, 34.6%, and 10% as detected by GA, SP, and BL methods, respectively. These detected growth releases reflected the legacy effects of recorded flood and drought events within the study area and its vicinity. High precipitation events (i.e. flood years) recorded after drought events exhibited a positive impact on tree radial growth and were observed as growth release events. For a more comprehensive understanding of the specific requirements of this species under changing climatic conditions and to contribute to the development of improved forest management strategies, it is advisable to conduct further detailed studies on growth release analysis, supported by inventory data related to forest management operations.

An improved method for sand wave morphology discrimination in rivers by combining a flow resistance law and support vector machines

A parameterized expression for sand wave morphology in rivers is established using a flow resistance law while accounting for sediment incipient velocity. A distinct relation is drawn between the proposed characteristic parameters and the sand wave morphology based on flume data. Support vector machines (SVMs) are then used to separate the boundaries of the sand wave morphology due to the high classification accuracy of SVMs. The boundary line data from each sand wave morphology is extracted and fitted to establish a discriminant standard, which is then successfully validated using experimental and quantifiable data. Also, based on the foregoing methodoly, it is further discovered that the short-term significant fluctuation of sand wave morphology is closely correlated with significant channel changes in rivers with a high width-depth ratio, using Yellow River Estuary as an example.