Simeon Ribagin

Investigation of relationships between bulk properties and fraction properties of crude oils by application of the intercriteria analysis

ABSTRACT Data from assays of 244 crude oils (condensates, extra light, light, intermediate, and heavy crudes) were processed by the InterCriteria Analysis with the aim to investigate the relationships between bulk properties and fraction properties of the crude oils and the degree of similarity between them. It was found that except the crude bulk properties sulfur, Conradson carbon, and metals content all other studied crude bulk properties exhibited lack of statistically meaningful relations or presence of weak statistically meaningful relations with the crude fraction properties. The use of the InterCriteria Analysis showed that crudes with very similar properties could be identified when a large crude database is available. In this way based on a previous experience in oil refining a selection of potentially beneficial new crudes for processing in a refinery could be made.

Generalized Net model of asymptomatic osteoporosis diagnosing

Osteoporosis is a growing major public health problem with impact that crosses medical, social, and economic lines. It is now recognized that it is extremely important to diagnose osteoporosis before a fragility fracture occurs. The purpose of the present study is to give an example of application of Generalized Nets in orthopedics and traumatology and to propose a novel approach for diagnosing the asymptomatic osteoporosis in elderly patients.

Generalized Net Model of the Scapulohumeral Rhythm

The dynamics of the upper extremity can be modeled as the motion of an open kinematic chain of rigid links, attached relatively loosely to the trunk. The upper extremity or upper limb is a complex mechanism which includes many bones, joints, and soft tissues allowing various movements in space. The shoulder is one of the most complex musculoskeletal units not only in the upper limb but also in the entire human body. Codman [7] understood the complex and dependent relationships of the structures of the shoulder when he coined the term “scapulohumeral rhythm” to describe the coordinated motion. The purpose of the paper is to present a simple mathematical model of the scapulohumeral rhythm using the apparatus of the Generalized Nets Theory [1, 2]. The presented model is a part of a series of generalized net models of the upper limb developed by the authors (see [22, 23]).

Generalized net model of the upper limb vascular system

In a series of papers, generalized net models of the human body and its systems are described in general. Each generalized net model of a particular system can be complicated and detailed. In this paper we develop a generalized net model of the upper limb vascular system. A generalized net is used to construct a model which describes the process of circulation of the blood and lymph in the upper limbs. In the present paper short remarks on generalized net modeling are given and an extended generalized net model of the upper limb is constructed.

Power frequency spectrum analysis of surface EMG signals of upper limb muscles during elbow flexion – A comparison between healthy subjects and stroke survivors

After a stroke, motor units stop working properly and large, fast-twitch units are more frequently affected. Their impaired functions can be investigated during dynamic tasks using electromyographic (EMG) signal analysis. The aim of this paper is to investigate changes in the parameters of the power/frequency function during elbow flexion between affected, non-affected, and healthy muscles. Fifteen healthy subjects and ten stroke survivors participated in the experiments. Electromyographic data from 6 muscles of the upper limbs during elbow flexion were filtered and normalized to the amplitudes of EMG signals during maximal isometric tasks. The moments when motion started and when the flexion angle reached its maximal value were found. Equal intervals of 0.3407 s were defined between these two moments and one additional interval before the start of the flexion (first one) was supplemented. For each of these intervals the power/frequency function of EMG signals was calculated. The mean (MNF) and median frequencies (MDF), the maximal power (MPw) and the area under the power function (APw) were calculated. MNF was always higher than MDF. A significant decrease in these frequencies was found in only three post-stroke survivors. The frequencies in the first time interval were nearly always the highest among all intervals. The maximal power was nearly zero during first time interval and increased during the next ones. The largest values of MPw and APw were found for the flexor muscles and they increased for the muscles of the affected arm compared to the non-affected one of stroke survivors.

Intuitionistic Fuzzy Evaluations of the Elbow Joint Range of Motion

Following (Ribagin et al. 2015, In: 19th International Workshop on IFSs, [8]), in this paper it is proposed a technique to evaluate the functional capacity of the elbow joint during a complex movement using intuitionistic fuzzy and interval valued intuitionistic fuzzy sets. The membership and non-membership values are not always possible up to our satisfaction, but in deterministic (hesitation) part has more important role here, the fact that in decision making, particularly in case of orthopedic physical assessment, there is a fair chance of the existence of a non-zero hesitation part at each moment of evaluation. Based on our previous study here we will introduce intuitionistic fuzzy estimations of flexion-extension and pronation-supination movements of the elbow joint.

Generalized Net Model of Adhesive Capsulitis Diagnosing

Adhesive capsulitis is a musculoskeletal condition of the shoulder characterized by pain and gradual loss of the global shoulder motion. Proper diagnosis of adhesive capsulitis is extremely important for designing a coordinated exercise program and reliable monitoring progress during treatment. In this investigation we present a successful example of Generalized Nets (GN) application in orthopedics and propose a novel approach to timely detection of adhesive capsulitis. The developed GN-model provides a framework that can be used by primary care practitioners to guide diagnostic processes for patients suspected to have adhesive capsulitis and might assist in optimizing patient outcomes and more effective treatment. The method proposed in this investigation accurately identifies the various steps during the diagnosing processes and significantly improve the health care level. Obtained so far results could be used to assist in the decision making in the diagnostic processes.

Generalized Net Model of Muscle Pain Diagnosing

Pain is the most common symptom of the many musculoskeletal pathologies. Musculoskeletal pain affects the muscles, ligaments, tendons, nerves and bones and might be caused by diverse factors. Musculoskeletal pain ranges from mild to severe. It can be local or diffuse, and acute or chronic. Due to the wide range of conditions that may cause such a symptom, diagnosing process is challenging and a systematic approach is necessary. In this investigation we present a successful example of generalized nets application in medical diagnosing and propose a novel approach leading to the appropriate diagnostic considerations. The method proposed in this investigation accurately identifies the various steps during the muscle pain diagnosing process and significantly improves the health care level. Obtained so far results could be used to assist in the decision making in the diagnostic processes.

A Note on Intuitionistic Fuzzy Modal-Like Operators Generated by Power Mean

In this paper we propose new type of intuitionistic fuzzy modal-like operators generated by the application of the power mean. We study some of their properties and establish some relations between them.

Generalized Net Model of Adolescent Idiopathic Scoliosis Diagnosing

Of the many postural disorders commonly found in the population, scoliosis is the most complex and the most difficult to diagnose and treat. Adolescent idiopathic scoliosis affects 2% to 4% of adolescent population. Although most of those patients will not develop clinical symptoms, scoliosis can progress to rib deformity and respiratory compromise, and can cause significant cosmetic problems and emotional distress for some patients. Accordingly, early detection is the key factor to prevent the curve magnitude progress, as well as to ensure an appropriate and successful treatment. Proper diagnosis is extremely important for designing a coordinated exercise programs and reliable monitoring progress during treatment. The purpose of the present study is to present a successful example of Generalized Nets application in orthopedics and to propose a novel approach to timely detection of adolescent idiopathic scoliosis and its categorization.