This paper provides experimentally determined estimates of the scale of fluctuation of the principal variables employed in modeling chloride-induced corrosion for reinforced concrete; i.e., the surface chloride content (Cs) and apparent diffusion coefficient (Dapp). The estimation of the scale of fluctuation, θ, is based on the analysis of experimental data recorded on a bridge in South East Ireland prior to its extensive rehabilitation in 2007. In determining the scale of fluctuation the paper considers two commonly used methods; i.e., the maximum likelihood method and the autocorrelation curve-fitting method. The reliability of both methods is discussed. Introduction of the kriging statistical interpolation method is demonstrated to improve the reliability of the estimates of the scale of fluctuation. The results obtained from the analysis are compared with values in the literature proffered by other researchers. arabic 16 English 119
Omran Kenshel(1-2013)

أتسمت السنوات الماضية بتطورات وتحديات عديدة كان لها آثار مباشرة على القطاع العام، ومن أهم هذه التحديات اختلاف دور الدولة في المجتمع ، والتغيرات البيئية ، والتخصيص ، وتطور تكنولوجيا المعلومات والاتصالات، والعولمة. ومن أجل أن يتمكن القطاع العام من مواجهة هذه التغيرات الاقتصادية والتكنولوجية والبيئية ينبغي الاستفادة من التطورات الحديثة في الإدارة في كيفية التعامل مع مثل هذه الشئون. ويعتبر أسلوب إعادة الهندسة من أحد أبرز الظواهر الإدارية الحديثة من بداية التسعينات. يشكل توطيد الأساليب الفعالة للنجاح أحد المجالات الأساسية التي تستلزم البحث والدراسة في مجال إعادة الهندسة.يتلخص مجال البحث في تدني مستوي أداء الشركة محل الدراسة نتيجة لانخفاض كفاءة عملياتها الحالية، لاستبعاد الإدارة العليا لمدى أهمية إعادة الهندسة في تطوير وتحسين الأداء. لذا فان الدراسة تهدف إلى إمكانية التعرف على الأسباب التي تحول دون تطبيق مفهوم إعادة الهندسة كأداة لرفع أداء الشركة العامة للكهرباء فى ليبيا. ولكي نتمكن من دراسة هذه المشكلة واقتراح الحلول اعتمد الباحث الأسلوب الكمي للبحث من خلال تصميم صحيفة استبيان وتوزيعها على عينة عشوائية بنسبة 50% من مجتمع الدراسة،والمتمثلة في ثلاثة إدارات تابعة للشركة العامة للكهرباء،وهي إدارة الموارد البشرية، وإدارة شؤون العاملين،وإدارة المعلوماتية حيث تكونت هذه العينة من 98 مفردة تم اختيارها عشوائيا لاختبار صحة الفرضيتين الآتيتين :استبعاد الإدارة العليا للشركة لمفهوم إعادة الهندسة يؤثر تأثيرا كبيرا على أداء الشركة محل الدراسة.قلة الكفاءات الفنية لتطبيق أسلوب إعادة الهندسة بالشركة محل الدراسة يؤدي إلى القصور في تطبيق هذا الأسلوب وبالتالي تدني أداء الشركة وعدم تطورها.تم إجراء التحليلات الإحصائية ، للبيانات التي تم تجميعها من صحيفة الاستبيان، واختبار الفرضيتين باستخدام البرنامج الإحصائي الشهير (SPSS) و باستخدام اختبار T test ، وتوصلت الدراسة إلى نتائج من أهمها أن استبعاد الإدارة العليا لأهمية تطبيق أسلوب إعادة الهندسة يؤثر على أداء الشركة ، كما أن العاملين بالشركة ينقصهم الوعي والإدراك بمتطلبات التحسين، وكذلك الرغبة والقدرة لإنجاز الأهداف المرجوة من عمليات التغيير لتحسين وتطوير الأداء، وخلصت الدراسة إلى تقديم بعض التوصيات لعل من أهمها:- لفت نظر القائمين على الإدارة العليا بالشركة محل الدراسة إلى أهمية استخدام نموذج إعادة الهندسة لتحسين مستوى أداء الأعمال بالشركة.دعم الشركة بالعناصر المؤهلة والقادرة على تبني أسلوب إعادة الهندسة لتطوير وتحسين أداء عمليات الشركة لتحقيق مستهدفاتها في زيادة الأرباح من خلال تقديم أفضل المنتجات والخدمات للعملاء عبر احدث وسائل تكنولوجيا المعلومات. Abstract The past years were characterized with many developments and challenges which had a direct impact on the public sector. Among the most important of these challenges, the divergence of the State’s role in the society, environmental changes, privatization, development of information technology and communication and globalization. In order for the public sector to face these economic changes, technological and environmental, advantage should be taken of recent developments in management to deal with such changes and developments , as re-engineering is considered one of the most prominent phenomena of modern management in the early nineties. The consolidation of the critical factors for success is one of the key areas for research and study in the field of re-engineering. The main problem of the research is briefed in the low level of the company's performance under study as a result of the low efficiency of its existing operations. This may be a result of exclusion of the senior management to the importance of re-engineering in the development and upgrading of performance. Therefore, the study aims at the possibility to identify reasons that prevent the application of re-engineering concept as a tool to upgrade the performance of the General Electricity Company of Libya (GECOL). In order to study this problem and propose solutions, the researcher adopted the quantitative method to search through the design of a questionnaire distributed to a random sample of 50% of the study community representing three departments belonging to the General Electricity Company; Human Resources Department, Personnel Department and information Department. This sample consists of 98 items, randomly selected to test the validity of the following two hypotheses The exclusion of the company senior management to re-engineering concept to affect the performance of the company subject matter of present study 2. Lack of technical competencies to apply the method of re-engineering in the company subject matter of study leads to deficiencies in the application of this method and hence the low performance of the company. The statistical analyzes of the data that was assembled through the questionnaire and the T test of the above two hypotheses using the well known statistical software (SPSS), were conducted. The study showed the exclusion of company senior management of the importance of applying re-engineering which affects the performance of the company. It also showed that the employees of the company lacked awareness and understanding of the requirements of the improvements as well as the desire and ability to achieve the desired goals of the processes of change and development to improve company Performance Company. This study concluded many recommendations, the most notably are: 1. raising awareness among those in charge of the senior management at the company under study to the importance of application of re- engineering model to improve the business performance of the company. 2. Providing the company by qualified personnel that are able to adopt re-engineering in the company to develop and upgrade the performance of the company's operations so as to achieve its objectives in increasing its profits though providing the best products and services for the customers though up-to-date information technology means.
رجب صالح سليمان (2013)

Estimating the Reliability (Probability of Failure) of Reinforced Concrete (RC) structures in marine environments has been of major concern among researchers in recent years. While General (uniform) corrosion affects the reinforcement by causing a uniform loss of its cross-sectional area, Pitting (localized) corrosion concentrates over small areas of the reinforcement. Many studies have focused on the effect of general corrosion, the effect of pitting corrosion on the structure reliability has not been fully investigated. Furthermore, due to the variability associated with the parameters involved in the reliability estimation of the corroded structure, this paper focuses on the effect of variability of pitting corrosion on the structure reliability. The analysis also takes into consideration the Spatial Variability (SV) of key deterioration parameters often neglected in previous studies. The authors have used their experimental data in modeling SV parameters of a specific deterioration parameter. The analysis adopted here used Monte Carlo (MC) simulation technique to construct a Spatial-Time Dependent model to estimate the girder reliability. The results showed that pitting corrosion potentially has a far more aggressive effect on the structure reliability than general corrosion and that pitting corrosion affects shear resistance far more severely than it would affect flexure resistance. The analysis showed that after 50 years of service, the reduction in the beam reliability due to pitting corrosion was 51% higher than that caused by general corrosion and that considering SV has caused the reliability predicted in terms of pitting corrosion to decrease by 12%. In the case of general corrosion, the decrease in beam reliability was only about 2% for the SV scenario.
Omran Kenshel, Mohamed Sulieman (12-2021)