The development of a new integral control model based on the analysis of three complex systems in Serbia

The aim of this paper is to analyse the results of research carried out in the railway, mining, and electric power systems in Serbia and form a new integral control model. The three methodological procedures are applied. First, analytical-synthetic methodological approach breaks down complex technical system into three parts: bio-cybernetic system, “operator”; technical system, “technology”; and additional system, “working environment.” Second, network planning method is used to analyse time, according to the critical path method. Third, fuzzy analytic hierarchy process determines the key research factors. General results of research are new integral control model, and new research areas and activities. The most prominent factors are: in “bio-cybernetic system”—operator’s arm reach, body postures and movement sequences, operator’s work, occurrence of stress, and occurrence of fatigue; in “technical system”—location and dimension of control desk, display panel, video display terminal, symbols on video display terminal, colours in control centres, and suitability of the keyboards; and in “supporting system”—illumination in control centres and relative humidity. Based on the analysis of factors and synthesis of results, the following recommendation are proposed: new control desk design; new display panel design; new design of the main and local lighting; new illumination and contrast characteristics, and environmental impact assessment. For research on a variety of complex technical systems, new integral control model can be applied, with corresponding extensions.     

Interaction between an operator and the control desk at the control room of the railway traffic: A Serbian experience

The subject of this paper is the interaction between an operator and the control desk at the Railway Traffic Control Room (RTCR) in Nis, Serbia. The following methods were used for this research: operators' anthropometric measurement; determining of maximum force of the movements of operators' arms; an analysis of workload of the movements of operators' arms, heads and torsos, and an analysis of errors in operators' movements in response to visual cues. The paper presents the following results: static parameter of 20 anthropometric measures of 41 operators' bodies were measured; nine corresponding dimensions of particular body parts for 5th, 50th, and 95th percentile were calculated; 10 characteristic work angles were measured; five corresponding functional body parts were calculated; times and distances covered by operators' arms were measured; maximum forces used for these movements were calculated; positions and number of movements of arms, heads, and torsos of operators were determined, and movement errors and probability of movement errors in choice of direction, arms and cumulative conditional probability were calculated. The research was conducted with the aim of discovering determining factors of mutual synchronization of the operator and desk.     

A Note on the Ohya-Masuda Quantum Algorithm

We analyze the Ohya-Masuda quantum algorithm that solves the so-called satisfiability problem, which is an NP-complete problem of the complexity theory. We distinguish three steps in the algorithm, and analyze the second step, in which a coherent superposition of states (a pure state) transforms into an incoherent mixture presented by a density matrix. We show that, if nonideal (in analogy with nonideal quantum measurement), this transformation can make the algorithm to fail in some cases. On this basis we give some general notions on the physical implementation of the Ohya-Masuda algorithm.     

The influence of genotypic variation in protein composition on emulsifying properties of soy proteins

This study describes the relationship between the emulsifying properties of soybean proteins and their composition, i.e., glycinin (11S) and β-conglycinin (7S). Twelve investigated soybean genotypes showed significant differences in storage protein composition. The β-conglycinin concentration positively correlated with extractable soluble protein content, which was positively correlated with protein extractability. These data suggest that the level of β-conglycinin has a positive influence on protein extractability. The emulsion activity index (EAI) was strongly and positively correlated with the 11S∶7S ratio and strongly and negatively correlated with the concentration of β-conglycinin. The emulsion stability index (ESI) showed a moderate positive correlation with the monomeric form of glycinin and a strong positive correlation with the ratio of the monomeric to dimeric form of glycinin. No association was evident between ESI and EAI. Also, no relationship was found between ESI or EAI and extractability. Based on these data, it appears that the 11S∶7S ratio strongly reflects the ability of soybean proteins to form emulsions, whereas the ratio of the two different forms of glycinin may be crucial factors for the stability of soybean protein emulsions. Thus, understanding the relationship between protein composition and functionality could be useful for further improvement of functional behavior of soy proteins in food systems.     

Development and Application of a Decision Support System for Human Reliability Assessment – A Case Study of an Electric Power Company

This paper describes the human reliability assessment using absolute probability judgment (APJ) method in the Electric Power Company of Serbia (EPS). Taking into account conventional APJ approach, a new decision support tool EPS‐APJ was developed. The EPS‐APJ tool is intended for use by a group of experts for human error probability assessment. The basic goal of the tool is to facilitate the process of decision‐making by experts, in the complex environment of the electric power companies. The usefulness of this new tool is approved in a case study of use of the EPS‐APJ for the purpose of the analysis of a repair intervention on a 10/0.4‐kV steel lattice tower ‘Nogaje’, in the EPS. For the purpose of this study, a database on work‐related injuries, accidents, and critical interventions occurred over a 10‐year period was created. The research comprised analysis of 1074 workplaces, with the total of 3997 employees. The case study performed at the EPS has confirmed that the EPS‐APJ tool for quantification of human errors is highly applicable, comprehensive, and simple to use. Comparison of the results obtained by application of the EPS‐APJ tool versus the basic APJ method has confirmed the accuracy of the decision support tool, and significant speed advantage in conducting an expert evaluation. Copyright © 2015 John Wiley & Sons, Ltd.     

An improved non-adiabatic FEM model of a line-to-earth fault in buried power cables

It is shown in this paper that the non-adiabatic nature of phase-to-earth fault thermodynamics in buried power cables can be modelled in an even more precise manner by using the FEM. The nonlinear FEM model has been created on the basis of an authentic case of fault caused by a previous mechanical damage of the cable sheath and insulation, as well as heat sources, thermo-physical and electrical material properties as functions of temperature and time. The proposed model is applicable to power cables of all voltage levels with different polymer insulations laid in soils with changeable moisture content, as well as to the dry arc tracking or wet arc tracking phenomena in PVC-insulated cables.     

Protein profiles and total antioxidant capacity of water‐soluble and water‐insoluble fractions of white brined goat cheese at different stages of ripening

This study deals with proteolysis and total antioxidant capacity of proteins of white brined cheese prepared from overheated goat milk and ripened for fifty days. Proteolytic changes were reflected through the relatively low level of soluble nitrogen (50 days ripened cheese had 15.32 g/100 g of water‐soluble nitrogen, 8.1 g/100 g of TCA‐soluble nitrogen and 2.69 g/100 g of PTA‐SN), intensive proteolysis of α_s2‐CN during initial 10 days of ripening (up to 50.70% of initial content) and its much slower degradation through further 40 days, slow but continual decrease of β‐CN content (up to 85.14% of residual content) and high level of proteolytic products tightly bounded into gel network. Total antioxidant capacity of water‐soluble and water‐insoluble fractions increased after cheese ripening. These findings could be useful for better understanding and control over the production of white brined goat cheese as highly valuable functional product.     

金刚石薄膜在第一壁材料表面的应力研究

目的 提出在第一壁材料(钨穿管部件)表面沉积金刚石薄膜,并系统研究金刚石薄膜厚度对应力的影响。方法 采用数值模拟和实验表征方法。利用ANSYS workbench模拟软件,在建立钨穿管部件表面金刚石薄膜有限元模型及模型方程的基础上,对影响金刚石薄膜热残余应力的厚度因素进行探讨;采用微波等离子体化学气相沉积法(MPCVD),在钨穿管部件表面沉积不同厚度的金刚石薄膜,并利用拉曼光谱法和洛氏硬度计压痕法对薄膜的应力进行表征。结果 模拟显示,随着金刚石薄膜厚度增加,薄膜最大主应力值和最大剪应力值均呈现出先减少后增加趋势,在薄膜厚度为75~100 μm时处于最低,小于金刚石薄膜通常的断裂强度(700 MPa),同时最大应力落差区域出现在薄膜边缘处。通过实验表征得到金刚石薄膜表面呈现出拉应力,在薄膜厚度为(103.56±0.5)μm时,金刚石薄膜中间区域应力值最低,与VDI3198标准对比,压痕坑达到HF1和HF2效果。结论 钨穿管部件表面金刚石薄膜厚度为(103.56±0.5)μm时,不容易出现裂纹和与基底的剥离现象,具有较好的附着性。     

Characterization of proteins from kernel of different soybean varieties

BACKGROUND: Total soybean proteins, storage proteins, glycinin (11S) and β‐conglycinin (7S) fractions and their respective subunits in seven soybean varieties were analyzed. In this work we also present the correlation between concentration and activity of bioactive proteins, lipoxygenase and proteinase inhibitors. RESULTS: Glycinin and β‐conglycinin comprise about 750 g kg^?1 of the bean storage protein and as such account for both quantity and quality of the kernel protein. The 11S concentration of the varieties studied ranged from 503.4 to 602.9 g kg^?1 and those of 7S varied from 178.2 to 230.6 g kg^?1 of total extractable proteins. The ratio of 11S/7S proteins varied from 2.43 to 3.29 among the varieties. A very strong positive correlation was found between the concentration of Kunitz trypsin inhibitor and activity of total trypsin inhibitor (r = 0.96). However, lipoxygenase concentration did not show a strong correlation with lipoxygenase activity. CONCLUSION: It appears that among the seven ZP soybean genotypes there are genotypes with different amounts of subunits that should be bred in the future for a desired level of protein components. Copyright © 2010 Society of Chemical Industry