Scipedia: Collection of Perspectives in Science

The timber truss: The studying of the behaviour of the spatial framework joint

Scipedia content — Wed, 05 Oct 2016 12:26:00 +0200

Using of timber in civil engineering is increasing at the moment. Main timber elements are used for main supporting structures, typically for buildings, roofs, footbridges or towers. This work studies unique timber trusses as a supporting roof structure of spatial timber building. Timber trusses are used as roof supporting construction for objects with open inside space, especially halls or office buildings. This paper resolved critical joint in roof construction which is created by four timber trusses. The FEM model monitored strain changes in critical places of resolved joint.

Durability assessment of concrete bridge deck considering waterproof membrane and epoxy-coated reinforcement

Scipedia content — Wed, 05 Oct 2016 12:26:06 +0200

The effect of waterproof membrane and steel reinforcement protection on the concrete bridge deck is modeled. The attention is paid to the durability prediction related to steel reinforcement corrosion initiation based on the chloride penetration. Thus 2-D finite element chloride ingress model is applied. The transient finite element model serves to solve Ficks second diffusion law using the computer tool compatible with the Matlab environment. The model focuses on the transport of chloride ions through a reinforced concrete bridge deck with and without the effect of waterproof membrane and on an estimate of the concentration of chlorides at the reinforcement level or in places with damage to the epoxide coating of the reinforcement. The model allows the incorporation of damage to the waterproof insulation under the asphalt coating. The time to chloride induced onset of corrosion is predicted and results are compared. The effect of water proof membrane reinforcement protection strategy typical for Central Europe and epoxy-coating protection widely used in North-Western United States is evaluated.

Valuation of the China internet company under a real option approach

Scipedia content — Wed, 05 Oct 2016 12:26:12 +0200

The objective of the paper is description, application and verification of the real option methodology in financial decision-making of the internet company in China. There is the real option methodology described. Subsequently financial characterisation of internet Baidu company is given. Crucial part consists in calculation of the company value under several scenarios and real option alternatives. We conclude that generalised real option methodology is suitable method of valuation of the internet company under China economical conditions.

Experimental measurements of subsoil–structure interaction and 3D numerical models

Scipedia content — Wed, 05 Oct 2016 12:26:20 +0200

Use of combination of experimental measurements, tests in situ and numerical modelling is optimal approach to obtain reliable results of subsoil–structure interaction. Input data for numerical analyses were obtained by experimental loading tests of three different types of concrete slabs. Loading was performed out using experimental equipment. The unique experimental equipment was constructed in the area of Faculty of Civil Engineering, VŠB-TU Ostrava. Analyses of interaction of reinforced concrete slabs with subsoil were solved by application of inhomogeneous half-space. The main focus was to verify the aptness of application of inhomogeneous half-space in relation to the slab deformations in comparison of different types of reinforcements of concrete slab.

Real options valuation with changing volatility

Scipedia content — Wed, 05 Oct 2016 12:26:24 +0200

This paper aims at the valuation of real options with changing volatility. Volatility change is a typical feature of real investment projects, where the riskiness of cash flow generated by the project can change significantly during the project life span. In this paper, there is explained how the problem of changing volatility can be considered if binomial lattice and replication strategy is used for real option valuation. There are recombining and non-recombining lattice used and constant and increasing volatility are analysed and results compared. In situation when volatility is changing, two approaches overcoming this problem are employed and compared.

The current economic situation in China and its impact on the Czech Republic

Scipedia content — Wed, 05 Oct 2016 12:26:38 +0200

Nowadays, many companies try to enter to the international sector and to extend here their activity. Their international cooperation is an integral part of the action; it is necessary to know the cultural differences. Therefore it is important to understand the social development including the Social Progress Index and the secondary analysis of an economic situation in China; and its subsequent impact on the economy not only in the Czech Republic based on evaluation of Czech-Chinese business relations. China was in the last five years the male rotor of the world economic growth and became a significant importer of commodities. Last year, the Chinese economic growth rate slowed down, which could have negative consequences on other economies. This is also the possible reason for some Czech companies leaving the Chinese market; they transfer their production parts back to Europe or India. A presumption of high living standard, which all countries of the world and their inhabitants want to achieve, is according to the current paradigm of economic science the economic growth. The economy does not take pace in a vertical line, but at the horizontal level as the meaning of sharing in the net among the individuals. And the cooperation does not take place in the horizontal line but in the vertical line, which essentially changes the way of peoples working.

A brief review of revocable ID-based public key cryptosystem

Scipedia content — Wed, 05 Oct 2016 12:26:51 +0200

The design of ID-based cryptography has received much attention from researchers. However, how to revoke the misbehaviour/compromised user in ID-based public key cryptosystem becomes an important research issue. Recently, Tseng and Tsai proposed a novel public key cryptosystem called revocable ID-based public key cryptosystem (RIBE) to solve the revocation problem. Later on, numerous research papers based on the Tseng-Tsai key RIBE were proposed. In this paper, we brief review Tseng and Tsais RIBE. We hope this review can help the readers to understand the Tseng and Tsais revocable ID-based public key cryptosystem.

The Stirling engine mechanism optimization

Scipedia content — Wed, 05 Oct 2016 12:26:58 +0200

A special type of the gas engine with external combustion is called Stirling engine. The mechanism has two pistons with two volumes inside. The pistons are connected together through cooler, regenerator and warmer. The engine effectivity depends on the piston movement behaviour. The usual sinusoidal time curve leads to low effectiveness. The quick movement from lower to upper position with a certain delay in both top and bottom dead centres is more effective. The paper deals with three types of mechanisms, analyzing the piston movement, and their behavior. Special emphasize is taken to the piston movement regime.

Carbonaceous particles in the air of the Moravian-Silesian Region, Czech Republic

Scipedia content — Wed, 05 Oct 2016 12:26:55 +0200

Black carbon (BC), elemental carbon (EC) and organic carbon (OC) are emitted as primary particles from incomplete combustion from fossil fuel, industry, residential heating and biomass burning. Carbon compounds account for a large fraction of airborne particulate matter. Above-mentioned forms of carbon particles can be used for the identification of pollution sources. The following work focuses on individual emission sources in the Moravian-Silesian Region, and their portion in air pollution.

Estimation of initial elastic properties of 2D homogenised masonry model based on tensor scale indices

Scipedia content — Wed, 05 Oct 2016 12:27:09 +0200

The paper discussed numerical approach for an estimation of initial elastic material properties for homogenised models of masonry. The tensor scale parameter is utilised. The paper discusses the principles of the use of the tensor scale for such task and it also discusses current limitations of the procedure. A numerical example is provided to illustrate the practical use of the proposed method.

Contribution to fire resistance analysis of statically indeterminate structures

Scipedia content — Wed, 05 Oct 2016 12:27:14 +0200

Structural fire resistance, as integral part of structural design, is determined by testing or by calculations. This paper is focused on statically indeterminate structures where thermal expansion is restrained and significant internal forces occur in the structure leading to possible plasticization and subsequent redistribution of internal forces. In this paper different approaches of fire resistance testing are described, together with brief description of two experiments focussed on verification of behaviour of a statically indeterminate steel frame exposed to high temperature which were carried out at VŠB-TU Ostrava. The paper is complemented with calculation of steel and concrete simple frame structure exposed to elevated temperature.

Analysis on complex structure stability under different bar angle with BIM technology

Scipedia content — Wed, 05 Oct 2016 12:27:19 +0200

Sun Valley, the landmark building of World Expo in Shanghai, which has free surface with single-layer reticulated shell structure, is a typical complex structure. CAD/CAM integrated information system to design is used for the complex structure; however, it is a very rigorous process to be used widely. The relevant technology of the Sun Valley is not open to the public at present, so we try to use BIM technology to model the Sun Valley, including architecture modelling and structure analysis. By analysis of the Sun Valley structure using this method, it is proved that the problems in modelling may be solved by writing some script codes in Rhino software and the stability of the model can also be analyzed. The new approach is viable and effective in combination with different softwares such as Rhino, Revit, and Midas in solution of the complex shaped surfaces’ structure for modelling and calculation.

Income inequalities in China: Stylized facts vs. reality

Scipedia content — Wed, 05 Oct 2016 12:27:25 +0200

There have been many papers recently (both theoretical and empirical) analyzing the problem of income inequality in China. Most of them usually state that the income inequality in China is growing in two dimensions – among the regions and between the urban and rural areas. Moreover, an opinion that reducing the inequality must be connected with sacrificing some part of economic growth prevails. These results seem to be widely accepted also by the media and politicians. In this paper we provide evidence that the income inequality remains stable in last years and that its relationship with economic growth is very ambiguous. Using the comparison with some other countries, we document that the inequality in both dimensions mentioned above does not change significantly faster than in other countries.

Water supply systems and their influence on increasing operational safety in industry

Scipedia content — Wed, 05 Oct 2016 12:27:28 +0200

The reliability of the technical manufacturing base of each state depends on the supplies of energies and drinking water in standard as well as extraordinary conditions. An extraordinary event or crisis situation can be caused by natural influences and anthropogenic events. Whereas in standard conditions, the supply of energies follows from contractual relationships, in case of extraordinary event it follows from a real situation that has occurred in the concerned entity of technical infrastructure. A common condition of technical–operational safety and manufacturing activity of all entities in standard and extraordinary situations is the reliability and continuity of water supplies for technological and sanitary purposes. This article presents what the threats and natural and anthropogenic conditions that can disrupt or completely exclude manufacturing processes are and how these threats can be effectively coped with in the real environment.

EU-China cooperation on regional policy

Scipedia content — Wed, 05 Oct 2016 12:27:32 +0200

Although the European Union and China are different in terms of area, population, economic, social, political and cultural development, both of them have to face similar challenge – the significant regional disparities and unbalanced regional development. Based on this the EU-China cooperation on regional policy has been launched and there is huge potential to develop mutual learning initiatives to allow their regions developed. The main aim of this paper is to outline the trends in evolution and perspectives of EU-China cooperation on regional policy.

Risk efficiency of hedging strategy in China financial market

Scipedia content — Wed, 05 Oct 2016 12:27:36 +0200

This paper presents the analysis of China financial market and method of hedging optimization for compute expected shortfall risk based on attitude towards risk under the Black–Scholes model. The application demonstrates an example of the efficient hedging strategy for call option in the Black–Scholes model based on geometric Brownian motion with loss function. The data of illustrations which applies in China financial market. The resulting efficient hedges allow the investor to interpolate in a systematic way extreme of partial hedging (between no hedge and full hedge) that depend on the accepted level of shortfall risk.

Using scaled physical model for assessment of mechanical damping of power plant boiler structure

Scipedia content — Wed, 05 Oct 2016 12:27:46 +0200

To determine dynamic response of mechanical system is always a complex issue. One of the core inputs for such a task is a coefficient of logarithmic damping decrement. There is no way how to determine this coefficient analytically; it needs to be measured on the final product. There has been a large amount of dynamic tests carried out on common structures and the results have been incorporated in design codes. Nevertheless, power plant boiler structure differs significantly from common structures. To provide a large number of dynamic tests on real facility is very difficult for many reasons. Using a scaled model is a way how to achieve relevant data based on repeatable experiment.

Intelligent transportation systems for Czech ageing generation

Scipedia content — Wed, 05 Oct 2016 12:27:52 +0200

In the Czech Republic owning and utilising of a car is one of the best remedies against a diminishing of cruising radius in old age and a comfortable mean to sustain autonomy and independence of living as well as social relations. Physical handicaps and limits of the elderly could be compensated today by sophisticated technical solutions. Promotion of specialised driver-assistance systems in the cars and advancement of the demand for age relevant cars with high-tech-optimisation should be the remedy; It is expected that these technical means will be used to a far greater degree in the future for the purposes of preventing road accidents (active safety) and to reduce the impact of the road accidents that do occur (passive safety) to senior citizens. The use of telematic should help in preventing accidents. Technical development increasing the safety of vehicles for older passengers need not be the privilege of a few. It will be necessary to co-operate with manufacturers to ensure that technical innovations are available to all and attainable as soon as possible for a wide range of new vehicles. The possibilities for equipping older vehicles already on the roads with new technical means of prevention should also be investigated. With changing attitudes and conditions the desire to travel for services, business and leisure represents a potential major new source of ideas for IVIS and ADAS designers and producers. Senior drivers represent a potential major new source of ideas for IVIS and ADAS designers and producers. The telematic development including IVIS and ADAS designed to reduce traffic accidents and to support elderly drivers in a suitable and user-oriented way may be appropriate solution.

Optimization of hydraulic parts using adjoint optimization

Scipedia content — Wed, 05 Oct 2016 12:27:56 +0200

Modern fluid mechanics examines understanding, predicting and directing of fluids in the fluid structures. But new computational methods need to find out the optimal solution of each hydraulic system because of minimization of power losses. Consequently, this article looks through the shape optimization of hydraulic parts using adjoint optimization method. It is most used gradient-based method. This approach enables to calculate the objective function sensitivities in consideration of the design variables (Kyriakos and Papadimitriou, 2008). Many producers talk about the optimized solutions, but only small part from them use all possibilities for finding the best one. It is motivation why in this paper the shape optimization of the hydraulic valve component with respect to minimization of pressure losses is presented.

Flexural Behavior and Strut-and-tie Model of Joints with headed bar details Connecting Precast Members

Scipedia content — Wed, 05 Oct 2016 12:28:01 +0200

This paper focuses on an investigation of an improved longitudinal joint with headed bar details connecting precast decked bulb tee girders for accelerated bridge construction. The testing study included two phases. In phase I, five beam specimens with various headed bar details and a continuous reinforced specimen were tested under flexure loadings. A headed bar detail with 152 mm lap length was recommended for further study. In phase II, two slabs connected by the selected joint were tested under flexure and flexure-shear loadings. Test results were evaluated based on structural behaviors including capacity, deflection, and failure mode. At last, a validated strut-and-tie model was developed to anticipate the capacity of the improved longitudinal joint. It shows that the proposed headed bar details can provide a continuous force transfer in the joint. The lap length interacting with the spacing of the headed bar is the most significant parameter of the improved joint details. To develop a full strength joint, the lap length should not be less than 152 mm and be designed by the strength requirement. The strut-and-tie model can provide a conservative strength anticipation of the joint and it is the lower bound of the ultimate capacity of the joint.

Effect of Amputation on re-Symmetrization and Physical Behaviors of Cassiopea xamachana

Sabrina Weiler — Tue, 11 Feb 2025 20:58:03 +0100

The purpose of this experiment was to investigate the physical behaviors and the re-symmetrization rate of the Cassiopea xamachana based on cutting ¼ through the manubrium (center of Cassiopea) versus ¼ amputation not including the manubrium. Jellyfish have four radial root canals, defined as tetramerous radial symmetry, all equally symmetrical. Re-Symmetrization is the process of reorganizing one’s body parts to regain function after a loss of anatomical structure. This process takes approximately four days to complete to regain full function. Cassiopea xamachana swims upside down which is normal for the jellyfish, while swimming right side up and crashing into objects is abnormal. There were two groups: Group A was cut ¼ through the center, and Group B was cut ¼ off center. Each group had seven jellyfish, ensuring that each tank was not too crowded and each tank had similar environments. The jellyfish pre-amputation was used as a control for the Cassiopea’s behaviors. The trial resulted with Group A dying sooner and having a slower pulsation rate than Group B. However, it had a faster re-Symmetrization rate compared to Group B. In conclusion, injury to the manubrium has an effect on the Cassiopea. Limitations of the study included the type of equipment used as the jellyfish were very delicate and finding a way to maintain the ammonia levels overnight and during the weekend. Future work that will be explored will be how different factors such as environmental changes affect their re-Symmetrization rate and physical behaviors.