Partially commutative and differential graded algebraic structures

PhD ThesisThe objects of study in this thesis are partially commutative and di erential graded algebraic structures. In fact my thesis is in two parts. The rst on partially commutative algebraic structures is concerned with automorphism groups of par- tially commutative groups and their nite presentations. The second on di erential graded algebraic structures is concerned with di erential graded modules. I have given a description for Aut(G ), the automorphism group of the partially commutative group G following Day's work, where is a nite simple graph. I have given a description for the subgroup Conj(G ) of automorphism group Aut(G ) following Toinet's work. We have found a nite presentation for the subgroup ConjV of the automorphism group Aut(G ). I have developed AutParCommGrp (Finite Presentations of Automor- phism Groups of Partially Commutative Groups and Their Subgroups) a package using the GAP system for computation of a nite presentation for Aut(G ), Conj(G ) and ConjV respectively. In the second part of the thesis we consider the following situation: Let K be a eld of characteristic two and let R = K[x1; x2; ; xn] be a graded polynomial ring, graded in the negative way. Suppose M is a di erential graded R-module with di erential @ of degree P. We have constructed a classi cation for some types of di erential graded R-module where P 2, n > 1. This classi cation gives a partial algorithm to test whether such modules are solvable. For modules outside the classi cation we cannot decide, using our methods, whether or not they are solvable. Also, we have proved in one case that M is solvable when R is a graded polynomial ring, graded in the usual way (non-negatively graded) with (P 2, n > 1). We have developed an algorithm and written a GAP package SDGM (Solvable Di erential Graded Modules) to check whether the di erential graded R-module M with di erential @ of degree P is solvable or not. Documentation has been written for all the packages above

Topological geometry analysis for complex dynamic systems based on adaptive control method

Several models had been proposed for dynamic systems, and different criteria had been analyzed for such models such as Hamiltonian, synchronization, Lyapunov expansion, and stability. The geometry criteria play a significant part in analyzing dynamic systems and some study articles analyze the geometry of such topics. The synchronization and the complex-network control with specified topology; meanwhile, the exact topology may be unknown. In the present paper, and by making use of the adaptive control method, a proposed control method is developed to determine the actual topology. The basic idea in the proposed method is to receive evolution of the network-node

Analysis of Simulation Outputs for the Mutual Effect of Flow in Weir and Gate System

يمكن الحد من مشكلة المواد المعلقة وترسبها بإستخدام نظام جريان مشترك يتكون من هدار وبوابة. وتهدف محاكاة هذا النظام إلى فهم وتحليل التأثير المتبادل لهما.  لهذا الغرض تم تنفيذ عمل تجريبي في المختبر للمقارنة والتحقق من دقة نتائج المحاكات في هذا النظام وذلك باختبار هدار وبوابة كمنشأ واحد ذو حواف حادة وبتغيير ارتفاع البوابة لأربع مرات وتسجيل مناسيب السطح وقيم التصريف. أجريت عمليات المحاكاة بالاعتماد على النموذج RNG k- ε للاضطرابات وقد أظهرت مقارنة السطح الحر للجريان والتصريف موثوقية مقبولة.  وأظهر التحليل أن انفصال الجزئين من الجريان يتم في منسوب متغيير، يبدأ من منسوب أقرب لحافة الهدار في التصاريف المنخفضة ثم يبتعد نحو الاسفل ليصل نصف المسافة بين الحافتين تقريبا عند ارتفاع عمق الماء أعالي المنشأ. وتزداد نسبة تصريف الهدار الى تصريف البوابة من 0.4 إلى 1.8 عند تقليل فتحة البوابة الى نسبة 60٪.  ومع زيادة عمق ماء المنبع بنسبة 46٪ يزداد تصريف البوابة بالنسب ٪5، ٪7، ٪12، ٪26 لفتحات بوابة 2، 3، 4، 5 سم على التوالي في حين أن تصريف الهدار يزداد حوالي 5 مرات.  كما أن الأداء في النظام المشترك أفضل بنسبة 5٪ إلى 20٪ مقارنة مع العمل المفرد التقليدي له. وضمن حدود هذة الدراسة تم اقتراح نموذجان رياضيان للتنبؤ بتصريف الهدار وبتصريف البوابة ذات معامل تحديد مقبول.The problem of suspended material and its deposition can be reduced by the combined system of weir and gate flow. Simulating this system aims to understand and analyse the mutual effect of them. Experimental work has been carried out to validate models of the combined system. Vertical sharp edges of gate and weir are tested by changing four times gate opening. The simulations base on RNG k- ε turbulence model and a comparison between flow surface profile and discharge has been done and they showed acceptable reliability. The investigation indicats that two flow portions separate at different levels depending on upstream depth and this separation level falls to reach halve of the distance between system edges as the depth increases. The relative weir to gate discharge increases from 0.4 up to 1.8 as gate opening decreases 60%. As total depth of flow upstream (H) increases by 46%, the discharge of gate increase 5%, 7%, 12%, 26% for gate opening of 2, 3, 4, 5 cm respectively, while the weir dischage increase about 5 times. The Weir in combined system performs better by 5% to 20% as compared with the conventional one. Within the study limitations, two mathematical models are suggested to predict discharge of weir in a system and for the gate with acceptable coefficient of determination

Civil conflict effect on e-commerce adoption among small and medium enterprises (SMEs) in Kurdistan region of Iraq

There are limited studies on E-commerce adoption among Small Medium Enterprises (SMEs) in countries experiencing civil conflicts. Hence, the objectives of this study were to investigate the factors influencing E-commerce adoption and whether civil conflict plays a moderating role in the Kurdistan Region. This study used the Technological, Organizational and Environmental (TOE) Model to develop the research framework. This study was underpinned by the Diffusion of Innovations Theory (DOI) and the Resource Dependence Theory (RDT). Eight variables representing the technology (relative advantage, compatibility, complexity), organizational (organizational readiness, organizational innovativeness, absorptive capacity) and environmental (role of government and relational trust) were tested, and civil conflict was included as a moderator. Data were collected through self-administered questionnaires in 393 SMEs in the Kurdistan Region (Erbil, Sulaimaniyah and Duhok) using the stratified sampling method. However, after data cleaning, only 293 questionnaires were valid for further analysis. The result reveals that six variables (compatibility, complexity, organizational readiness, absorptive capacity and relational trust) have significant relationship with E-commerce adoption. However, organizational innovativeness and the role of government show insignificant relationship with E-commerce adoption. Interestingly, civil conflict moderates the relationship between relational advantage and the role of government in E-commerce adoption. This study contributes to the richness of TOE, DO1 and RDT with the inclusion of absorptive capacity, organizational innovativeness and civil conflict to the research framework. Also this study offers valuable insights to managers, and policy- makers who are responsible for assisting SMEs in the new paradigm business operations. The result also contributes to the explanation of E-commerce adoption levels and the government could formulate strategies to encourage SMEs to adopt E-commerce in the civil conflict areas. Conclusions, limitations and suggestions for future studies are also highlighte

Adaptive and identification two tanks system in control

The classical approach to system identification is to identify the transfer function on the basis of measured data. The goal of this research, with the aid of Matlab package, is to both identify and adaptively control a laboratory non-linear two tanks system which is simulated in a Simulink model block. Sampling time and model structure selection will be introduced first. Then, concentration will be on the OLS and IV methods of estimating parameters as they will be used in the Matlab identification toolbox. The system accordingly will be identified to obtain both discrete and continuous linear function models at operating points of 3 and 6. Adaptive and self-tuning control is the second part of this report where self-tuning PI control will be implemented based on RLS and phase margin design algorithms. Relay-based auto-tuning PI control is the second part control method, and practical comparison between them is provided at the end of this repor

A presentation for the subgroup of compressed conjugating automorphisms of a partially commutative group

‎Let $G_{Gamma}$ be a partially commutative group‎. ‎We find a finite presentation for the subgroup $Conjv(G_{Gamma})$ of compressed‎ ‎vertex conjugating automorphisms of the automorphism group‎ ‎$Aut(G_{Gamma})$ of $G_{G}$‎. ‎We have written GAP packages which compute presentations for $Aut(G_{Gamma})$ and its subgroups‎ ‎$Conj(G_{Gamma})$ and $Conjv(G_{Gamma})$‎

Biodegradation of Polymeric Insulators Used in Electrical power

المواد البوليميرية لها مجموعة متنوعة من الاستخدامات بسبب التنوع الهيكلي. يعد تحللها البيولوجي مصدر قلق شائع لأنه عند استخدامها كعوازل كهربائية  فإن انهيار سلامتها الهيكلية يعرض الناس لمخاطر كهربائية. تبدأ عملية تحلل العوازل بواسطة الأغشية الحيوية بتكوين غشاء حيوي على سطحه. يجب أن يكون تكوين الأغشية الحيوية في ظل ظروف بيئية مناسبة مثل الرطوبة أو البيئة الرطبة. تعرض هذه الورقة عملية التحلل البيولوجي للعوازل البوليميرية. يتناول العمل إلى العمليات التي تشارك في نفس العوامل ، والعوامل التي تزيد من عملية التحلل البيولوجي. بمجرد تكوين الأغشية الحيوية على سطحها ، ستفرز الكائنات الحية الدقيقة إنزيمات تستطيع مهاجمة وتحلل سطح البوليمر. يخلص البحث إلى أن العوامل الأكثر شيوعًا التي تساعد في التحلل الحيوي هي تركيب البوليمرات، وطبيعتها البلورية، والعوامل البيئية.Polymeric materials have a variety of uses due to structural versatility. Their biodegradation is a common concern since when used as electrical insulators the breach of their structural integrity exposes people to electrical dangers. The process of degradation of the insulators by biofilms begins by the formation of a biofilm on its surface. Formation of the biofilm has to be under appropriate environmental conditions like in a damp or moist environment. This paper presents the process of biodegradation of polymeric insulators. It looks at the processes that are involved in the same and the factors that amplify the biodegradation process.  Once the biofilms have been formed on their surface, the microbes will secrete enzymes that can attack and hydrolyze the surface of the polymer. The paper concludes that the most common factors that aid the biodegradation are the composition of the polymers, the crystalline nature, and the environmental factors

Issuing Digital Signatures for Integrity and Authentication of Digital Documents

In this paper, we developed a secure system for issuing digital signature for digital documents and certificates using message digest algorithm (MD5). The developed system is providing the integrity and authentication for certificates by combining the information of participant and supply them to MD5 algorithm to produce a unique hash key of 32 digits which is hard to guess or attack. The process provides a certificate which allows for the authentication of a document at any time. The proposed system used and tested to produce digital certificate for participant of electronic seminars in Mustansiriyah university which were about 1000 certificate. The results were good and very fair to authenticate certificates and preventing forgery

Properdin is a modulator of tumour immunity in a syngeneic mouse melanoma model

Background and Objectives: Tumours are often low immunogenic. The role of complement, an innate immune defence system, in tumour control has begun to be elucidated, but findings are conflicting. A role for properdin, an amplifier of complement activation, in tumour control has recently been implicated. Materials and Methods: Properdin-deficient and congenic wildtype mice were injected subcutaneously with B16F10 melanoma cells. Tumour mass and chemokine profile were assessed. The frequencies of CD45+CD11b+ Gr-1+ cells were determined from tumours and spleens, and CD206+ F4/80+ cells were evaluated in spleens. Sera were analysed for C5a, sC5b-9, and CCL2. Results: Whilst there was no difference in tumour growth at study endpoint, properdin-deficient mice had significantly fewer myeloid-derived suppressor cells (MDSCs) in their tumours and spleens. Splenic M2 type macrophages and serum levels of C5a, sC5b-9, and CCL2 were decreased in properdin-deficient compared to wildtype mice. Conclusions: The presence of intact complement amplification sustains an environment that lessens potential anti-tumour responses