Rough Block Research Articles

Contribution of fractal dimension theory into the uniaxial compressive strength prediction of a volcanic welded bimrock

This study was carried out on Sille agglomerate which is a typical volcanic welded bimrock. Two precious historical monuments, Koimesis Tes Panagias Church and Sekili hill settlement carved in Sille agglomerate, have maintained their stability without any support for centuries although suffering from weathering and various stability problems. However, due to its heterogeneity and sampling difficulties, the overall strength of Sille agglomerate has not been investigated yet. This paper presents the relationships between fragmentation fractal dimension (DF), fractal dimension of rough block surfaces (DR), number of blocks (BN), and volumetric block proportion (VBP) and the overall uniaxial compressive strength (UCS) of the Sille agglomerate. By using these properties as inputs, three statistically significant empirical models were developed for estimating the UCS of the Sille agglomerate. The results revealed that the DF and DR may be good predictors to estimate the UCS of welded volcanic bimrocks, and defining the properties of blocks by means of fractal theory provides significant contribution to the estimation of the UCS. It is observed that the failure planes in the core samples predominantly pass through the boundaries between matrix and blocks, and such behavior may indicate that the weakest component of the Sille agglomerate is boundaries. Accordingly, the UCS decreases due to the high DR values which create more or further weakest zones in the bimrocks. Finally, it is concluded that the negative correlation between the UCS and the VBP was attributed to increase of the DR due to the increase of the VBP.

Reversible Data Hiding Based on Structural Similarity Block Selection

Reversible data hiding (RDH) methods are widely used in many privacy-sensitive real-time applications for digital images. As an efficient RDH method, prediction-error histogram (PEH) shifting technique has found wide application for its high efficiency in increasing embedding capacity. Nowadays, the performance of most PEH-based methods is evaluated only by Peak Signal to Noise Ratio (PSNR) or Structural Similarity (SSIM) Index. However, more and more applications require high quality in both PSNR and SSIM. Therefore, in this paper, we propose a new RDH method to concentrate on both PSNR and SSIM performance, which involves two key techniques: 1) an SSIM-based block selection technique, 2) a PEH-based optimal expansion bins selection technique. Through block selection, the original image is divided into two parts: smooth blocks and rough blocks. We select pixels of smooth block for double embedding and leave pixels of rough block unchanged. According to the optimal expansion bins, reasonable pixels are chosen for embedding such that the embedding distortion can be reduced. With these improvements, our proposed method has higher SSIM and PSNR after embedding compared to other PEH-based methods. The experimental results demonstrate its superiority over some state-of-the-art counterpart and other conventional PEH-based works.

Analysis of vibration high-frequency dynamic characteristics of wheelless rail vehicle system based on fuzzy logic control

Track irregularity is the main source of vibration excitation of vehicle-track weighing system, which has an important impact on the safety, stability and comfort of train operation, and it is also the main factor limiting the speed of train operation. Higher requirements are put forward for track smoothness with the rapid development of China’s railways. Therefore, it has a great theoretical and practical significance to study the relationship between track irregularity and random vibration of vehicle-track cooker-in system and the evaluation method of track smoothness. In this paper, a model construction method is proposed based on machine learning fuzzy logic control and neural network algorithm to analyze the high frequency dynamic characteristics of ballastless track wheel-rail vehicle system. Firstly, a numerical analysis model of high frequency dynamic characteristics of ballastless track wheel-rail vehicle system is established by using linear discrete elastic-yellow damper element connection model; Secondly, the Rough Set Block Neural Network is introduced to optimize the dynamic characteristic analysis model, and the intelligent model of model optimization analysis is established. Finally, the validity of the proposed algorithm is verified by simulation experiments of practical examples.

Usability Test of Application named SmartWALKing for Vulnerable Road Users

본 연구는 이동에서 불편함을 느끼는 교통약자들이 자신의 장애정도와 이동 능력에 맞는 최적의 경로를 탐색하고 선택할 수 있는 어플리케이션인 스마트워킹(“SmartWALKing”) 개발을 목적으로 진행되었다. 스마트워킹은 최단거리 위주로 안내하는 기존의 보행맵과 달리 이용자의 신체적 이동 능력을 고려하여 경로 및 안전 보행을 위한 각종 정보를 제공할 수 있는 것을 목적으로 한다. 본 논문은 여의도를 대상으로 진행 중인 어플리케이션 스마트워킹의 개발 과정에서 실시된 두 가지 현장조사에 대한 보고이다. 첫째는 안내된 경로에서 제공되어야 할 필요 정보의 종류와 표시 방식 등에 대한 조사이며, 둘째는 일반 보행맵과 스마트워킹 맵, 교통약자가 선택한 경로의 비교 고찰이다. 그 결과, 교통약자의 활발한 외출과 안전한 보행에는 보행의 시작점과 도착지점에 대한 정보가 매우 중요함을 확인하였다. 특히 외출에서 보행의 시작점이 되는 지하철의 승강기 위치, 환승정보 등을 포함하는 정보가 매우 중요한 것을 확인하였다. 또한 일반 보행맵과 스마트워킹 맵, 교통약자가 직접 이용하는 경로는 서로 상이하게 나타나는 경우가 있었다. 휠체어사용자는 보도블록의 거친면을 지양하여 경로로 선택하지 않고, 보차혼용도로를 선택하는 경향이 있었다. 이러한 내용은 스마트워킹 맵과 보행환경 정비를 위한 자료로 심층적으로 분석되어야 할 것이다.The purpose of this study is to develop an application named “SmartWALKing” that enables the disabled to search and select the best route for their mobility. SmartWALKing is characterized by providing a route considering the physical mobility of the user, and various information for safe walking on the route, unlike the existing pedestrian map that guides the shortest distance. This paper is a report on two field surveys conducted during the development of ongoing an application SmartWALKing. The first part is a survey of the types of information needed to be provided in the guided route and the way of displaying them. The second part is the comparison of a general pedestrian route, SmartWALKing, and routes selected by the mobility-handicapped. As a result, it was confirmed that information about the starting point and arrival point of walking was very important for the active outing and safe walking of the traffic weak. In particular, it was confirmed that the information including the lift position, transfer information, etc. of the subway which is the starting point of walking in the outing is very important. In addition, the general pedestrian walking route, SmartWALKing route, and the route chosen by the mobility-handicapped are sometimes different. Wheelchair users tend to choose a car-walker mixed road than sidewalk because of the rough block. These contents should be analyzed in depth as data for smart walking map and pedestrian environment maintenance.

ENHANCEMENT OF PIXEL VALUE ORDERING BASED DATA HIDING BY ROW BLOCK PARTITION

The development of information and communication technology that support digital data transmission such as text, image, audio and video gives several effects. One of them is data security that becomes the main priority during the transmission process. Pixel-Value-Ordering (PVO) which one of data hiding methods can be implemented to achieve the requirement. It embeds data on maximum pixel and minimum pixel in a blok which is a part of the carrier image. However, PVO has capacity a problem, that only 2 bits per block can be hidden. To handle this problem, we propose a new approach by dividing blocks dinamically based on its complexity. These blocks are grouped into 4: smooth block, semi-smooth block, normal block and rough block. Using this approach, the stego capacity can be improved up to 2.6 times in average of previous method by keeping the quality stego more than 65 dB for all testing image.

New approaches to the implementation of the mining technology of dimension stone using a close-set drilling

The analysis of the current state the non-blasting monolith extraction technology was conducted. The further research direction was substantiated. Has been considered and justified the rational parameters of close-set drilling technology of dimension stones. Solution is offered that consist the combined drilling (a close-set and a holes line drilling), that provides to increase of stone splitting efficiency under its own weight. The calculation of the parameters of the scheme of partial underdrilling at a monolith of stone with the purpose of reducing the volume of drilling works is given. Diagrams of tensile stress changes depending on the specific area of splitting were built. A rational correlation between the drilling parameters of the holes has been established by solving the problems of loading the cantilever beam and stress concentration by the Kirsch solution. The most important parameter for the implementation of this technology is the ratio of monoloth hight to its length. Engineering formulas are proposed for calculating the technological parameters of the realization of the “gravitational-hole” stone splitting. The configuration of a rough block of stones is determined under which this technology can be realized. Creating of close-set holes provides the increase of maximal tensile stress with equal values of specific splitting area ratio. It is established that the effective drilling depth of close-set holes is 43,2 % of monolith height. It is estimated that combined drilling method application of savings from drilling operation will be 11,36 %.

Role of Rubber Stiffness and Surface Roughness in the Tribological Performance on Ice

ABSTRACTThe aim of this work is to investigate the effect of slider surface roughness and stiffness on the friction between rubber compounds and ice surfaces in order to provide insight into rubber–ice friction generation mechanisms. For this purpose, rubber compounds were designed to have different levels of macroscopic roughness and cured stiffness by modifying the filler system and plasticizer loading. In order to accurately evaluate the effects of surface and bulk rubber property on ice friction, linear friction tests were performed on laboratory ice with varied frictional heat buildup by modifying the friction test protocol. The results showed that the friction force was in general increased through the ploughing effect of a rough rubber block sliding on smooth ice. The increase in friction by ploughing was more pronounced when the contacting rubber block had sufficiently low stiffness and when the accumulation of frictional heat on ice was sufficiently high. It was also evidenced that a sufficiently hard rubber with test conditions leading to low heat buildup on ice could nevertheless lead to an opposite influence of roughness on rubber–ice friction; that is, lower friction force with a slider with a higher roughness.

Experimental validation of theoretical methods to estimate the energy radiated by elastic waves during an impact

Estimating the energy lost in elastic waves during an impact is an important problem in seismology and in industry. We propose three complementary methods to estimate the elastic energy radiated by bead impacts on thin plates and thick blocks from the generated vibration. The first two methods are based on the direct wave front and are shown to be equivalent. The third method makes use of the diffuse regime. These methods are tested for laboratory experiments of impacts and are shown to give the same results, with error bars of 40 percent and 300 percent for impacts on a smooth plate and on a rough block, respectively. We show that these methods are relevant to establish the energy budget of an impact. On plates of glass and PMMA, the radiated elastic energy increases from 2 percent to almost 100 percent of the total energy lost as the bead diameter approaches the plate thickness. The rest of the lost energy is dissipated by viscoelasticity. For beads larger than the plate thickness, plastic deformation occurs and reduces the amount of energy radiated in the form of elastic waves. On a concrete block, the energy dissipation during the impact is principally inelastic because only 0.2–2 percent of the energy lost by the bead is transported by elastic waves. The radiated elastic energy estimated with the presented methods is quantitatively validated by Hertz׳s model of elastic impact.

STUDY ON WET PROCESSING OF BLOCK CHILLY

The purpose of this study is to examine the effect of drying time in weight and water content, combination effect of drying time and size of the material, and consumer acceptance to the product in the wet processing of chili blocks production. Method used in the research is completely randomized design (CRD) with two factorials are material size and drying time. Data were analyzed using ANOVA and further analysis using DMRT at 5% significance level. Organoleptic test result was analyzed using the Kruskal-Wallis and Tukey test for further analysis. Application of the equal drying time to two different size of material: rough and finest block chili, showed the result that water content of the rough block chili is lower than the finest block chilli. Application of the different drying time duration to the same size of chili showed the lower water content with increasing duration of drying time. The water content of the material tends to decrease with increasing duration of drying time. The level of consumer’s preferences to the product of wet processing of chili blocks production is equal for scents, but it’s different for color, texture and overall preferences.

STUDY ON WET PROCESSING OF BLOCK CHILLY

The purpose of this study is to examine the effect of drying time in weight and water content, combination effect of drying time and size of the material, and consumer acceptance to the product in the wet processing of chili blocks production. Method used in the research is completely randomized design (CRD) with two factorials are material size and drying time. Data were analyzed using ANOVA and further analysis using DMRT at 5% significance level. Organoleptic test result was analyzed using the Kruskal-Wallis and Tukey test for further analysis. Application of the equal drying time to two different size of material: rough and finest block chili, showed the result that water content of the rough block chili is lower than the finest block chilli. Application of the different drying time duration to the same size of chili showed the lower water content with increasing duration of drying time. The water content of the material tends to decrease with increasing duration of drying time. The level of consumer’s preferences to the product of wet processing of chili blocks production is equal for scents, but it’s different for color, texture and overall preferences.

The faces of Janus: modernism and hybridisation in the architecture of Lina Bo Bardi

From inside the echoing interior of a basketball court, large cut-out holes in the wall frame the convoluted, metropolitan landscape of São Paulo. From the outside, these holes look like hand-carved perforations in a rough and hollow concrete block. Lina Bo Bardi, the Italian-Brazilian architect, designed these unusual windows for the gymnasium of the SESC-Pompéia cultural and leisure centre between 1976 and 1982. These apertures are more than sills that control light and air (Figs 1, 2). They revive the etymological sense of the word janela, which means window in Portuguese.Like the two faces of Janus, they represent an ambivalent threshold. They exist between modern rationality and the spontaneity of everyday life and popular culture, merging where one begins and the other ends in Lina Bo Bardi's work. The window apertures exemplify the corollary of a long genealogy in the thinking and design of this unique architect, whose work defies easy classification. One of Lina Bo Bardi's major contributions to design was her focus on the cultural and anthropological character of architecture and her ability to hybridise modern and vernacular repertoires. She conceptualised this procedure as arquitetura pobre (simple architecture). Lina Bo Bardi's search for simplification and unpolished materials reflected her political and aesthetic interest in how Brazilian popular culture creatively dealt with the scarcity of material means. By doing so, she confronted privileged and disadvantaged social realities in Brazil. The development of this hybrid attitude came from her Italian experience, and can be seen in three major examples of her work spanning some twenty years: the Museum of Art of São Paulo, the Museum of Popular Art in Salvador, and the SESC-Pompéia. Her position as a woman and as a foreigner with easy access to the Brazilian architectural and cultural mainstream gave her a unique opportunity to realise her projects. Her dissonant voice cost her isolation for a long time until her work started to be valued in the 1980s. The spaces and buildings that Lina Bo Bardi designed look bare and sometimes even harsh. Yet, they manifest a deeply sensitive and intuitive approach that opened up the threshold between conflicting cultural spheres of modernisation in Brazil in the second part of the twentieth century.

Normal and Angular Motions at Rough Planar Contacts During Sliding With Friction

The planar dynamics of a rough block in nominally stationary or sliding contact with a counter-surface is studied in this work. Starting with the Greenwood-Williamson model of a rough surface, the analysis of elastic contact deflections is extended to accommodate angular as well as normal motions. The real area of contact and the normal contact force are obtained in terms of the relative approach and orientation of the surfaces. It is shown that angular and normal motions at frictional contacts are generally coupled. The contact area and normal contact force are shown to be nonlinearly related to the normal and angular motions. However, the contact area remains proportional to the normal load, even in the presence of angular motions. When the friction force is assumed to be proportional to the real area of contact, the coefficient of sliding friction will be unchanged by small relative rotations between the sliding bodies. Based on this contact and friction model, the nonlinear equations of motion that describe the planar contact vibrations of a sliding block can be written directly. Although a detailed analysis of the stability and response characteristics of these nonlinear equations is beyond the scope of the present work, a limited comparison of calculations and measurements taken on both stationary and sliding blocks indicate that the small amplitude contact vibrations are reasonably well captured by the model developed in this work.

Inscriptions from Macedonia

1. Edessa. This inscription is still where Leake first reported it, in the courtyard of the Metropolitan Church, the Dormition of the Virgin, built into the south end of the west wall of the Γραφεῖον of the Δεσπότης. Although it has been published half a dozen times, the text has never been read correctly in its entirety, largely because its height from the ground makes the taking of a photograph or the making of a squeeze, let alone a study of the letters, very difficult. I was fortunate to be able to examine it in situ, and the accompanying photograph of a squeeze will facilitate the establishment of the text (Plate 5).It is a rough block, c. 0·46 m. in height and 0·50 m. in width, with a moulding all round, the first line being engraved on the upper moulding. The letters are irregular, measuring on an average 0·025 m. in ll. 1–6 and 0·01 m. in ll. 7–18. The letter-forms, especially important in a dated inscription, are noteworthy. Alpha, delta, and lambda have short tails on the apex; in ll. 1–6 epsilon is square, in ll. 7–18 lunar; similarly in ll. 1–6 sigma is square, in ll. 7–18 lunar. The forms of mu and omega are to be noted; see the accompanying photograph. There are no ligatures.

Epigraphical Notes from Eastern Macedonia and Thrace

These notos are a result of a short tour in the autumn of 1896 through the coastlands north of the Aegean from Xerxes' canal to the Hebrus. Professor W. C. F. Anderson of Firth College, Sheffield, accompanied me. and gave much valuable help. Of the inscriptions which we copied the following seem to be either unknown, or imperfectly published or described, If I have overlooked a previous publication of any of them, I may plead the difficulty of finding out what has or has not been edited.1. Hierissos (Acanthus): in a wall near the Byzantine gate on the acropolis. Fragment of coarse marble block, 1 foot 11 inches high, 10 inches broad. Letters about 3½ inches. Published by Cousinéry, Voyage dans la Macédoine, t. II., p. 151; by Boeckh, C.I.G. 2007k; and, the epigraphic text only, by Le Bas, No. 1414.I believe that the right half of the stone has been cut away. If so, it is better to read with Cousinéry than with Boeckh. The stone may have marked the boundary of public land.2. Lympiada: in a wall on the beach. Rough block of granite, 3 feet 3 inches long, 1 foot 7 inches high. Letters 5½ to 3 inches, irregular and much weathered.