Sustainability of the Urban Housing Projects in the Yemeni Cities (An Evaluating Study – Taiz City)

بذلت بعض الجهود من قبل الحكومة اليمنية وبعض المنظمات الدولية بهدف المساهمة في حل مشكلة الإسكان والتي تعد من اهم المشاكل التي تعاني منها المدن اليمنية ومنها مدينة تعز، وقد تم تنفيذ بعض مشاريع الإسكان هدفت الى توفير السكن الملائم لبعض الفئات، ومن هذه المشاريع مشروع إسكان المتضررين من كوارث السيول (المهمشين)، ومشروع اسكان ذوي الدخل المحدود، ومشروع اسكان عمال النظافة والتي توزعت في انحاء مختلفة من المدينة، وبالرغم من الجهود التي بذلت لتوفير مشاريع الاسكان في مدينة تعز الا ان الملاحظ وجود العديد من المشاكل في مختلف الجوانب سوأً العمرانية أو البيئية أو الاقتصادية والاجتماعية، غياب الخدمات والمرافق العامة وصعوبة الوصول اليها وعدم التنوع في الاسكان وقلة المساحات الخضراء وغيرها من القضايا التي تهتم بها الاستدامة. لذلك جاء البحث ليركز على الاستدامة في مشاريع الإسكان كونها تمثل مدخلا شاملا متعدد الابعاد لتصميم وتقييم مشاريع الاسكان الحضري. وذلك من خلال استقراء الادبيات والدراسات السابقة ذات العلاقة للتعرف على مفاهيم الاستدامة وعلاقتها بمشاريع الاسكان والتوجهات التخطيطية الحديثة وبرامج التقييم، ومن ثم استخلاص مؤشرات يمكن من خلالها قياس مدى تحقق الاستدامة في عينة من مشاريع الاسكان بمدينة تعز، والخروج بتوصيات تساعد في معالجة جوانب القصور في مشاريع الإسكان الحالية وبما يساهم في رفع كفاءة المشاريع في المستقبل ويوفر السكن اللائق والعيش الكريم في مدينة تعز والمدن المشابهة لها. الكلمات المفتاحية: الاستدامة، تقييم الاستدامة، مشاريع الاسكان، تعز.Yemeni government and some international organizations exerted some efforts as a contribution to solve the problem of housing which considered a key problem facing Yemeni cities including Taiz city. Some housing projects had been executed to provide appropriate housing for some categories, including project for people affected by floods disasters (marginalized people), housing project for low income people, housing project for cleaning laborers which all distributed in various locations of the city. Notwithstanding the efforts exerted to provide housing project in Taiz, however, there are many problems in various aspects either architectural or environmental or economic or social such as weakness of uniformity in the architectural appearance, lack of diversity of housing, difficulty of access to services, shortage of green spaces and other issues that concern sustainability. Thus, this study aims to focus on the issue of sustainability in housing projects as they represent a wide access with multiple dimensions to design and evaluate urban housing, through study and analyze concepts of sustainably and its relation with housing projects, modern planning directions, evaluation tools and extracting indicators by which we can evaluate sustainability and scale the extent of achievement in the projects of housing in Taiz city and to conclude recommendations that may assist to address failure aspects in housing projects in the future in order to contribute to raising the durability of such projects and provide adequate housing and decent life for population of Taiz and other similar cities. Keywords: Sustainably, Sustainability evaluation, Housing projects, Taiz

Linear and Planar Array Pattern Nulling via Compressed Sensing, Journal of Telecommunications and Information Technology, 2021, nr 3

An optimization method based on compressed sensing is proposed for uniformly excited linear or planar antenna arrays to perturb excitation of the minimum number of array elements in such a way that the required number of nulls is obtained. First, the spares theory is relied upon to formulate the problem and then the convex optimization approach is adopted to find the optimum solution. The optimization process is further developed by using iterative re-weighted l1- norm minimization, helping select the least number of the sparse elements and impose the required constraints on the array radiation pattern. Furthermore, the nulls generated are wide enough to cancel a whole specific sidelobe. Simulation results demonstrate the effectiveness of the proposed method and the required nulls are placed with a minimum number of perturbed elements. Thus, in practical implementations of the proposed method, a highly limited number of attenuators and phase shifters is required compared to other, conventional method

Beam Pattern Optimization Via Unequal Ascending Clusters, Journal of Telecommunications and Information Technology, 2023, nr 1

In this paper, two different architectures based on completely and sectionally clustered arrays are proposed to improve the array patterns. In the wholly clustered arrays, all elements of the ordinary array are divided into multiple unequal ascending clusters. In the sectionally clustered arrays, two types of architectures are proposed by dividing a part of the array into clusters based on the position of specific elements. In the first architecture of sectionally clustered arrays, only those elements that are located on the sides of the array are grouped into unequal ascending clusters, and other elements located in the center are left as individual and unoptimized items (i.e. uniform excitation). In the second architecture, only some of the elements close the center are grouped into unequal ascending clusters, and the side elements were left individually and without optimization. The research proves that the sectionally clustered architecture has many advantages compared to the completely clustered structure, in terms of the complexity of the solution. Simulation results show that PSLL in the side clustered array can be reduced to more than −28 dB for an array of 40 elements. The PSLL was −17 dB in the case of a centrally clustered array, whereas the complexity percentage in the wholly clustered array method was 12 .5 %, while the same parameter for the partially clustered array method equaled 10%

Linear and Planar Array Pattern Nulling via Compressed Sensing

An optimization method based on compressed sensing is proposed for uniformly excited linear or planar antenna arrays to perturb excitation of the minimum number of array elements in such a way that the required number of nulls is obtained. First, the spares theory is relied upon to formulate the problem and then the convex optimization approach is adopted to find the optimum solution. The optimization process is further developed by using iterative re-weighted l1- norm minimization, helping select the least number of the sparse elements and impose the required constraints on the array radiation pattern. Furthermore, the nulls generated are wide enough to cancel a whole specific sidelobe. Simulation results demonstrate the effectiveness of the proposed method and the required nulls are placed with a minimum number of perturbed elements. Thus, in practical implementations of the proposed method, a highly limited number of attenuators and phase shifters is required compared to other, conventional methods

Beam Pattern Optimization Via Unequal Ascending Clusters

In this paper, two different architectures based on completely and sectionally clustered arrays are proposed to improve the array patterns. In the wholly clustered arrays, all elements of the ordinary array are divided into multiple unequal ascending clusters. In the sectionally clustered arrays, two types of architectures are proposed by dividing a part of the array into clusters based on the position of specific elements. In the first architecture of sectionally clustered arrays, only those elements that are located on the sides of the array are grouped into unequal ascending clusters, and other elements located in the center are left as individual and unoptimized items (i.e. uniform excitation). In the second architecture, only some of the elements close the center are grouped into unequal ascending clusters, and the side elements were left individually and without optimization. The research proves that the sectionally clustered architecture has many advantages compared to the completely clustered structure, in terms of the complexity of the solution. Simulation results show that PSLL in the side clustered array can be reduced to more than −28 dB for an array of 40 elements. The PSLL was −17 dB in the case of a centrally clustered array, whereas the complexity percentage in the wholly clustered array method was 12 .5 %, while the same parameter for the partially clustered array method equaled 10%