Small Blocks Research Articles

IS THE OIL AND GAS BLOCK POLICY IN IDONESIA EFFECTIVE? EMPIRICAL APPROACH BASED ON COMPANY RATING DEVELOPMENTS

Objective: This study aims to identify the empirical influence of the assessment criteria for Indonesian oil and gas auctions on total oil and gas block production. The role of remaining concession time, contract policy and block size are considered. Theoretical Framework: In this topic, the concepts and agency theories underlying the research are presented, providing a strong basis for understanding the context of the influence of oil and gas block policies in Indonesia. Method: This research uses an exploratory quantitative approach. The research sample consisted of 157 petroleum and 140 natural gas blocks that had carried out production activities. Ordinary least square (OLS) regression used to empirically test the hypothesis. Results and Discussion: The results show that the ranking of oil and gas companies has a significant positive effect on the productivity of blocks. Meanwhile, remaining concession time has a significant positive relationship only for the natural gas. This research also found a significant negative effect of the gross split contract on block production. Finally, it was found that company ranking had a positive and significant effect on production both in large and small blocks. However, the relationship between ranking and productivity is stronger and more consequential for large-scale blocks compared to small-scale blocks. Research Implications: Contract policymakers need to review the gross split policy because it is not in line with the initial goal of increasing efficiency. The results clearly show that strict government policies can reduce agency costs while encouraging oil and gas production, however, this can hinder the competitiveness of the sector. The government does not need to give excessive priority to high-ranking companies in managing small-scale blocks in order to attract new investors. Originality/Value: To the best of our knowledge, this research is the first study to develop a ranking method for oil and gas companies in Indonesia.

Truncated Differential-Neural Key Recovery Attacks on Round-Reduced HIGHT

Recently, differential-neural cryptanalysis, which integrates deep learning with differential cryptanalysis, has emerged as a powerful and practical cryptanalysis method. It has been particularly applied to lightweight block ciphers, which are characterized by simple structures and operations, and relatively small block and key sizes. In resource-constrained environments, such as Internet of Things (IoT), it is essential to verify the resistance of existing lightweight block ciphers against differential-neural cryptanalysis to ensure security. In differential-neural cryptanalysis, a deep learning model, known as a neural distinguisher, is trained to differentiate a target cipher from others, facilitating key recovery through statistical analysis. For successful differential-neural cryptanalysis, it is crucial to develop a highly accurate neural distinguisher and to optimize the key recovery attack algorithm. In this paper, we introduce a novel neural distinguisher and key recovery attack against the 15-round reduced HIGHT cipher. Our proposed neural distinguisher is capable of distinguishing HIGHT ciphertext by analyzing only a portion of the ciphertext, which we refer to as a truncated neural distinguisher. Notably, our experiments demonstrate that the truncated neural distinguisher achieves performance comparable to existing distinguishers trained on entire ciphertext blocks, while enabling a more efficient key recovery attack through a divide-and-conquer strategy. Furthermore, we observe a significant improvement in key recovery efficiency compared to traditional cryptanalysis methods.

Characteristics of Rock Avalanche Deposit in Wangjiapo, Ludian Based on UAV Aerial Image Recognition

Rock avalanche disasters in alpine and gorge regions are frequent and large in scale and cause severe damage. The movement of a rock avalanche is complex and has not been fully studied. The deposits of a rock avalanche can provide valuable insights into its movement process, which is crucial in understanding the rock fragmentation mechanism and predicting disaster-affected areas. Taking the Wangjiapo rock avalanche in Yunnan Province of China as an example, the size, shape and distribution characteristics of the deposit were analyzed based on field surveys, unmanned aerial vehicle (UAV) photography and image recognition technology. Initially, 3062 deposited rock blocks were manually measured in the field. Subsequently, the Particles/Pores and Cracks Analysis System (PCAS) was employed to identify 11,357 rock blocks with an area greater than 0.1 m2 from UAV orthophotos. By comparing the characteristics of the rock blocks obtained through image recognition and manual measurement, the statistical analysis of UAV aerial imagery combined with PACS proved feasible in studying the Wangjiapo rock avalanche. The results showed that the rock block movement was accompanied by fragmentation and sorting processes; furthermore, the roundness increased with the migration distance. Small blocks were more prevalent at the foot of the slope, while irregularly shaped, large blocks dominated in source areas. The movement of huge blocks was characterized by significant potential energy-driven features and inertia advantages, allowing them to travel farther than smaller blocks, and they tended to be concentrated in the central area of the deposit. Additionally, affected by the cementation degree of breccia and the topography, the blocks in the eastern and western deposit areas exhibited different fragmentation and deposition characteristics.

A Study on the Effect of Urban Form on the Street Interface Rhythm Based on Multisource Data and Waveform Classification

Good-quality urban street space is crucial for improving walkability. Frequency and amplitude are the main spatial characteristics of the street interface rhythm, known as a “virtual–real” relation. Exploring the mechanism influencing the urban street interface rhythm can help grasp the movement trend. In this study, the correlation between frequency and urban form is explored through a Pearson correlation analysis with multisource data, and the factors influencing the urban street interface rhythm are presented. The results indicate that frequency has a moderate negative correlation with the block scale and a moderate positive correlation with the number of pedestrian access entrances (PAE-n); the PAE-n also has a strong negative correlation with the block scale. Some spatial characteristics of outstanding streets from different countries are analyzed and discussed based on waveform classification. The regularities of interface rhythm that exist within multiple streets are found: multiple gaps on the street interface exist, acting as a “beat”, which regularly integrates or separates the street interface rhythm. The frequency and amplitude of the “beat” significantly affect streets’ walkability, and the amplitude is generally low and uniform, with good visual accessibility in all directions. A “Small Block and Dense Grid” becomes a key factor in improving walkability. Basic knowledge of the street interface rhythm in urban walking space research is supplemented by this study. Furthermore, theoretical guidance and parametric evidence are provided to improve walkability and promote the continuation of the traditional context.

Модель интерактивного обучения: полиморфный подход

Introduction. The peculiarity of building a model of interactive learning lies in the polymorphism of the term “interactive”, which has different forms of realization. Interactivity is considered from two positions: a high level of activity of students and the technology of using information and communication technologies in distance learning. It is required to eliminate the contradictions existing in the perception and realization of interactivity in learning. The aim of the study is to develop a model of interactive distance learning, taking into account the polymorphic approach in interactivity. Methodology and methods: study of methodological literature of domestic and foreign authors on the issue of organizing interactive learning, acquaintance with the experience of leading educational institutions and large companies promoting interactive technologies. The obtained materials were subjected to theoretical and empirical methods of pedagogical research. Findings of the study. The author proposes to expand the informativeness of the interactive learning model. In the case of activation of classes in the classroom there is a contact model – “interactive learning”. For distance learning it is necessary to introduce the “model of interactive learning” and structure it by realized activity: a passive “model of interactive learning”, an active “model of interactive learning” and an interactive “model of interactive learning”. Conclusion. Interactive technology of distance learning has peculiarities. It is effective at alternation of small blocks of information and requires realization of “active learning strategy” – controlled change of learners' activity during classes.

Evaluating Effects of Continuous Occlusion on Visual Letter Identification

Visual letter identification refers to humans’ use of a visual system to recognize the 26 letters in the English alphabet. Letters may be partially occluded by nonadjacent small occlusion blocks (called discrete occlusion) or a single occlusion block (called continuous occlusion) in the real world, thereby affecting visual letter identification. The effects caused by discrete occlusion have been investigated in existing research. The results indicate that humans possess the ability to identify partially occluded letters and a large occlusion ratio results in low identification accuracy. However, few studies have explored the effects caused by continuous occlusion and revealed precise reflections on occlusion effects. This study presents an evaluation to explore the effects of continuous occlusion on visual letter identification. A controlled experiment is designed to achieve two research goals: identifying the maximum extent of occlusion ratio (named upper bound) that does not affect visual letter identification and investigating the change patterns of the accuracy of occluded letter identification with the gradual increase in occlusion ratio. The experimental results are analyzed in detail, and three main findings are obtained. First, moderately occluded letters can be accurately identified in a continuous occlusion scene. Second, the precise upper bounds are obtained for each of the 26 letters. Lastly, the change patterns for the 26 letters present three nonlinear decline patterns. The findings could inspire technical advancements in the fields of visualization, computer vision, and healthcare.

USING THE INTEGRAL INDICATOR TO DETERMINE TI-ZR PRIORITY AREAS OF PLACERS

The article presents the author’s method of selection of priority areas of Ti-Zr placers using an integral indicator. As you know, the integral indicator is the ratio of the total beneficial effect from the development of the deposit to the total costs of operation, it is calculated as the difference between the value of conventional ilmenite (according to the US Geological Survey) (Mineral Commodity..., 2023) and the cost of obtaining overburden and processing the productive layer. Based on the methodology developed and presented in the article, an experiment was conducted on the data of one of the placer deposits located within the Ukrainian placer sub-province. It is proposed to develop it in small blocks that ensure high productivity, minimal impact on the environment and allow replenishment the mineral and raw material base of the titanium industry of Ukraine. This technique can be used at any deposit of titanium-zirconium ores both in Ukraine and abroad.

Measurement of computed tomography modulation transfer function with a novel polymethyl methacrylate phantom.

A novel phantom for measuring the 10% and 50% values of the modulation transfer function (MTF) for computed tomography scanners (CT) was investigated. The phantom was constructed by drilling rows of holes of different sizes and frequencies into a small block of polymethyl methacrylate (PMMA). The MTF at a given frequency was determined from the ratio of the range of Hounsfield units within the rows of holes at different frequencies, and the difference in Hounsfield units between air and PMMA. A MTF curve was plotted from measurements at different frequencies and the 10% and 50% MTF values were obtained from a cubic spline interpolation. The MTF results obtained with the drilled hole phantom method were compared to a conventional method - using a thin wire and Spice-CT ImageJ Plugin- and with identical acquisition and reconstruction parameters. The drilled hole phantom measured the 50% MTF with reasonable accuracy but underestimated the 10% MTF by 8.2% on average. MTF measurements were reproducible for repeated image acquisitions and with different users analysing the images, and the phantom was able to accurately measure the change in MTF when measured on images using different reconstruction kernels. The tool may find application as a cheap, easy to use method for routine QC testing of CT scanners.

A study on the classification of complexly shaped cultivated land considering multi-scale features and edge priors.

Obtaining accurate cultivated land distribution data is crucial for sustainable agricultural development. The current cultivated land extraction studies mainly analyze crops on a regular shape and a small block scale. Aiming at the problem of fragmentation of plots in complexly shaped cultivated land leads to variable scales and blurred edges and the difficulty of extracting the context information by kernel convolution operation of the CNN-based model. We propose a complexly shaped farmland extraction network considering multi-scale features and edge priors (MFEPNet). Specifically, we design a context cross-attention fusion module to couple the local-global features extracted by the two-terminal path CNN-transformer network, which obtains more accurate cultivated land plot representations. This paper constructs the relation maps through a multi-scale feature reconstruction module to realize multi-scale information compensates by combining the gated weight parameter based on information entropy. Additionally, we design a texture-enhanced edge module, which uses the attention mechanism to fuse the edge information of texture feature extraction and the reconstructed feature map to enhance the edge features. In general, the network effectively reduces the influence of variable scale, blurred edges, and limited global field of view. The novel model proposed in this paper is compared with classical deep learning models such as UNet, DeeplabV3 +, DANet, PSPNet, RefineNet, SegNet, ACFNet, and OCRNet on the regular and irregular farmland datasets divided by IFLYTEK and Netherlands datasets. The experimental results show that MFEPNet achieves 92.40 and 91.65 MIoU on regular and irregular farmland datasets, which is better than the benchmark experimental model.

Identifying the location and micellization of PEG-b-PCL multiblock copolymers in PLA/PCL blends via AFM nanoscale IR spectroscopy

The IR absorption mapping of two multiblock copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) segments (PEG-b-PCL) in poly(acid lactic) and poly(ε-caprolactone) blends (PLA/PCL) was performed via AFM nanoscale IR spectroscopy. These copolymers, having the same number average molar masses (Mn‾) but varying block sizes, were added into the blend in different amounts (1 and 5 wt%) using a co-rotating twin-screw extrusion. The results revealed that copolymers with smaller blocks are preferentially located near the interface when incorporated in small quantities. Increasing the copolymer content led to preferential diffusion into the PLA matrix. Compatibilization with the longer block-size copolymers also led to preferential diffusion in the PLA matrix, albeit with a tendency to form micelles. This hampers the overall mechanical properties of the blend, making the compatibilized blend more brittle than neat PLA. Compatibilization with the short block-size copolymers showed no micellization and improved the mechanical behavior of PLA/PCL.

Very high cycle fatigue characteristics of laser beam powder bed fused AlSi10Mg: A systematic evaluation of part geometry

This study explores the influence of geometry and part size on defect distribution, melt pool size, and mechanical characteristics in laser beam powder bed fused (LB-PBF) AlSi10Mg. Five distinct geometries—hourglass, small rod, small block, large block, and large rod—were fabricated under identical process parameters. Fully reversed ultrasonic fatigue testing, operating at a frequency of 20 kHz, was conducted to assess the very high cycle fatigue properties. The findings indicated that part geometry had a major impact on the fatigue properties of the material in the very high cycle fatigue regime. Specimens machined from large rods and large blocks had the lowest porosity and highest fatigue resistance. Microstructural analysis indicated that hourglass, small rod, and small block specimens had shallower melt pools and overlap depths compared to other geometries. This observation suggests a higher cooling rate in specimens with smaller cross-sectional areas, leading to the increased presence of entrapped gas pores and a lack of fusion defects. Understanding the relationship between part geometry and fatigue properties in LB-PBF components offers insights for optimizing design and manufacturing processes in additive manufacturing applications.

Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, AFM indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength not only depends on material properties but also on experimental conditions, such as the ice dimensions. Moreover, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication should be considered on soft surfaces.

A Multi-Objective Optimization Design for Enhancing Space Utilization and Minimizing Cutting Time in Nuclear Facility Component Decommissioning

According to the International Atomic Energy Agency’s requirements for the minimization of radioactive waste, nuclear facility components need to be cut into smaller blocks and packaged in waste containers during decommissioning. Therefore, it is important to increase the space utilization (SU) of the cut blocks in the containers while reducing the cutting time (CT). In engineering practice, increasing SU often leads to longer CTs, which poses a great challenge to improve the efficiency of the nuclear decommissioning process. To overcome this challenge and to determine the optimal operational parameters, this paper introduces a multi-objective optimization design method for cutting and packaging nuclear facility components. The goal is to increase SU while concurrently reducing CTs, ultimately minimizing the waste and reducing the decommissioning cost. First, we project the intricate three-dimensional (3D) irregular parts packing problem onto a two-dimensional plane to simplify the complexity inherent in 3D parts packing and to formulate a packing optimization model. Second, we employ the Morris method to perform global sensitivity analysis on critical parameters, including cutting angle, height, component radius, and plate thickness parameters, throughout the cutting process of nuclear facility components. This analysis produces global sensitivity indicators for each parameter, facilitating a precise assessment of the sensitivity values associated with different operational parameters. Finally, we formulate a multi-objective design optimization model for cutting and packing nuclear facility components that yields a series of alternative operating parameter solutions upon solving it. This methodology offers a resolution for the selection of optimal operational parameters in the decommissioning process of nuclear facility components, thereby attaining optimal outcomes in waste disposal and furnishing guidance for subsequent decommissioning activities.

A comparison of whole-mount and conventional sections for pathological mesorectal extension and circumferential resection margin assessment after total mesorectal excision

IntroductionThe objective of the study is to compare 2 techniques for histological handling of rectal cancer specimens, namely whole-mount in a large block vs conventional sampling using small blocks, for mesorectal pathological assessment of circumferential resection margin status and depth of tumor invasion into the mesorectal fat. MethodsThis is a prospective study including 27 total mesorectal excision specimens of rectal cancer from patients treated for primary rectal carcinoma between 2020 and 2022 in a specialized multidisciplinary Colorectal Unit. For each total mesorectal excision specimen, 2 contiguous representative tumoral slices were selected and comparatively analyzed with whole-mount and small blocks macroscopic dissection techniques, enabling comparison between them in the same surgical specimen. The agreement between the 2 techniques to assess the distance of the tumor from the circumferential resection margin as well as the depth of tumor invasion was evaluated with the Student’s t-test for paired samples, Pearson’s correlation coefficient, and the Bland-Altman method comparison analysis. ResultsComplete mesorectal excision was observed in 8% of cases. Circumferential resection margin involvement was observed in only one case (4 %). The whole-mount and small block techniques obtained similar results when we assessed the distance to the circumferential resection margin (t-test P = 0.8, r = 0.92) and the depth of mesorectal infiltration (t-test P = 0.6, r = 0.95). ConclusionsBoth gross dissection techniques (whole-mount vs multiple small cassettes) are equivalent and reliable to assess the distance to circumferential resection margin and the depth of mesorectal infiltration in the mesorectal fat in rectal cancer staging.

Dual image watermarking based on NSST-LWT-DCT for color image

Advanced internet technology allows unauthorized individuals to modify and distribute digital images. Image watermarking is a popular solution for copyright protection and ensuring digital security. This research presents an embedding scheme with a set of conditions using non-subsampled Shearlet transform (NSST), lifting wavelet transform (LWT), and discrete cosine transform (DCT). Red and green channels are employed for the embedding process. The red channel is converted by NSST-LWT. The low-frequency area (LL) frequency is then split into small blocks of 8×8, each partition block is then transformed by DCT. The DCT coefficient of (3,4), (5,2), (5,3), (3,5), called matrix M1, and (2,5), (4,3), (6,2), (4,4), called matrix M2 are selected for singular value decomposition (SVD) process. With a set of conditions, the watermark bits are incorporated into those singular values. The green channel is cropped to get the center image before splitting into 4×4 pixels. The block components are then selected based on the least entropy value for the embedding regions. The selected blocks are then computed using LWT-SVD. A set of conditions for U(1,1) and U(2,1) are used to incorporate the watermark logo. The experimental findings reveal that the suggested scheme achieves high imperceptibility and resilience under various evaluating attacks with an average peak signal-to-noise ratio (PSNR) and correlation value (NC) values are up to 43.89 dB and 0.96, respectively.

Analysis of power generation considering design and finishing materials of thermoelectric energy harvesting blocks

A thermoelectric-generator-based energy-harvesting block capable of continuously generating electricity 24 h a day using solar radiation and waste heat from a building exterior was proposed. The energy-harvesting block consists of a thermoelectric generator and a phase change material. This study aims to investigate the amount of power generated according to various designs and types of finishing materials for energy-harvesting blocks to increase the amount of power generated by small energy-harvesting blocks. It consists of a single-layer energy-harvesting block that removes the thermal resistor, and a double-layer energy-harvesting block that enlarges the area to increase radiation and convection. Four types of energy harvesting blocks applied with black coating were manufactured to increase the insolation absorption rate, and the temperature and open circuit voltage were measured. Among the four types of energy-harvesting blocks, the black-coated double-layer energy-harvesting block produced the maximum power generation of 0.0601 Wh/day. The black coating has a significant influence on the inflow of solar radiation and the amount of power generated, and the double-layer energy-harvesting block is a suitable design to maximize the amount of power generated.

Exploration of green index system from the perspective of urban renewal

In the context of China's urban sustainable development, the green index system can be used to assess and monitor the environmental impact and sustainability of urban renewal projects, provide scientific basis for decision makers, and guide urban renewal to develop in a green, low-carbon and sustainable direction. China has incorporated green development and ecological civilization construction into the "13th Five-Year Plan" outline, and clearly put forward the major task of "comprehensively improving the quality of cities" in the "14th Five-Year Plan" outline, in order to accelerate the transformation of urban development mode and carry out urban renewal action. From a macro point of view, in the process of urban renewal, how to use a better evaluation system to plan the future development of urban green space and combine it with design practice is becoming more and more important. From the micro point of view, how the public environment and architectural space in different cities react, reflect, and even promote the process of urban renewal. In many parts of China, urban renewal based on the small block model is encouraged to be widely adopted, and local environmental improvements promote public health and support the transformation of cities to sustainable models based on theoretical, practical and political dimensions. This paper analyzes the urban renewal measures under different scales of landscape, architecture and community, and illustrates their responses to the green index system in urban renewal through cases. From the perspective of urban renewal, the paper combines macro-planning transformation and micro-renewal to analyze the green ecological goals achieved in the process of urban low-carbon development and ecological restoration.

Withdrawn: Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength is not a material property, since it depends on the ice block size. As such, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication need to be considered on soft surfaces.

Analytical Solutions of Symmetric Isotropic Spin Clusters Using Spin and Point Group Projectors

Spin models like the Heisenberg Hamiltonian effectively describe the interactions of open-shell transition-metal ions on a lattice and can account for various properties of magnetic solids and molecules. Numerical methods are usually required to find exact or approximate eigenstates, but for small clusters with spatial symmetry, analytical solutions exist, and a few Heisenberg systems have been solved in closed form. This paper presents a simple, generally applicable approach to analytically solve isotropic spin clusters, based on adapting the basis to both total spin and point group symmetry to factor the Hamiltonian matrix into sufficiently small blocks. We demonstrate applications to small rings and polyhedra, some of which are straightforward to solve by successive spin-coupling for Heisenberg terms only; additional interactions, such as biquadratic exchange or multi-center terms necessitate symmetry adaptation.

Unveiling the First Neobatrachian (Anura) Discovered in the paleokarst system of Bolt’s Farm (Plio-Pleistocene; Cradle of Humankind), South Africa

ABSTRACT Anurans are widely diversified in South Africa, with more than 150 recognised species across the country. However, most the known fossil records of anurans are concentrated in the southern part of South Africa, within the rich Pliocene site of Langebaanweg. Isolated anuran elements have been recovered in the Pliocene deposits of the Cradle of Humankind, but none from the multi-localities site of Bolt’s Farm (Plio-Pleistocene). A small block containing an articulated anuran specimen was recently discovered from the Milo A site from Bolt’s Farm. We analysed this specimen using CT-scanning to describe its osteology. Surprisingly, the cavity housing the skeleton took the shape of the body of the individual, revealing a small sized individual with a triangular-shaped head. The preserved skeletal elements (around 50% of the skeleton) shows clear synapomorphies of the Ranoidea. A comparison between our specimen and members of all South African ranoid families allow us to highlight numerous osteological similarities between our specimen and taxa of the Pyxicephalidae, leading to a putative attribution to this large African family. In addition, the position of the body is identical to the position of a dormant pyxicephalid, suggesting that our specimen died during a dormancy period, in the dry season. This supports the current paleoenvironment reconstruction, an open savannah with marked seasonality.