The main challenge of military tactical communication systems is the accessibility of relevant information on the particular operating environment required for the determination of the waveform's ideal use. The existing propagation model focuses mainly on broadcasting and commercial wireless communication with a highs transceiver antenna that is not suitable for numerous military tactical communication systems. This paper presents a study of the path loss model related to radio propagation profile within the suburban in Kuala Lumpur. The experimental path loss modeling for VHF propagation was collected from various suburban settings for the 30-88 MHz frequency range. This experiment was highly affected by ecological factors and existing wave propagation effects such as reflection, diffraction, scattering, and Doppler effect. Radio propagation performance is evaluated by collecting received power at the allocated substation and comparing it against existing propagation models. The existing propagation model also will be tuned close to the measurement value by identifying the best path loss exponent to perform a suitable model for a suburban area. Theoretical assessments and analysis of the initial measurement stage for radio propagation show the extensive contribution of radio field from potential obstacles at lower VHF frequencies for both short and medium ranges around there. The explanation indicates the standard radio propagation prediction models that are generally reasonable for the suburban area. From the general error analysis, it is seen that, the performance of the LDPL with adjusting path loss exponent is the suitable model since it has least value of error metrics.
The present study addressed "Performance Appraisal of Human Resource Management and Its Effect on Achieving the Organizational Success", for the topics of performance appraisal of human resource management and the organizational success gained an increasing interest being relatively important and modern topics which had a great effect on the future of organizations.
The study aimed at revealing the pattern of appraising the performance of human resource management for the study sample, and whether it was qualified to lead the ministry towards the organizational success, for this purpose two main hypotheses were formulated: 1) there is a positive significant correlation between both variables: performanc
... Show Moreتفضيل السيولة - تضخم جانب الطلب - الاستقرار النقدي - معدل التضخم
Although renewable energy systems have become an interesting global issue, it is not continuous either daily or seasonally. Latent heat energy storage (LHES) is one of the suitable solutions for this problem. LHES becomes a basic element in renewable energy systems. LHES compensate for the energy lack when these systems are at low production conditions. The present work considered a shell and tube LHES for numerical investigation of the tube rotation influence on the melting process. The simulation and calculations were carried out using ANSYS Fluent software. Paraffin wax represents the phase change material (PCM) in this work, while water was selected to be the heat transfer fluid (HTF). The calculations were carried o
... Show Moreيهدف هذا البحث الى تصميم قائمة بمؤشرات القيم العلمية والاخلاقية التي ينبغي توافرها في محتوى كتاب الحاسوب للصف الثاني المتوسط، وتحليل محتوى الكتاب المذكور آنفاً وفقاً لها، وذلك عن طريق الإجابة عن السؤال الآتي: ما نسبة توافر القيم العلمية والأخلاقية في محتوى كتاب الحاسوب المُعد لطلبة الصف الثاني المتوسط الصادر من وزارة التربية العراقية/ المديرية العامة للمناهج في العام الدراسي ( 2017-2018) م؟ ولتحقيق هدفا البحث أ
... Show Moreهدفت الدراسة الى تحليل محتوى كتاب الرياضيات للصف الاول متوسط على وفق مكونات المعرفة الرياضية (المفاهيم الرياضية , التعميمات الرياضية, المهارات الرياضية والمسائل الرياضية )
وتفرعت منه الاسئلة الاتية :
مانسبة المفاهيم الرياضية المتضمنة في كل فصل من فصول كتاب الرياضيات للصف الاول متوسط وللكتاب ككل ؟
مانسبة المهارات الرياضية المتضمنة في كل فص
... Show Moreيهدف البحث الحالي إلى تحليل محتوى كتاب الحاسوب للصف الثاني متوسط وفق مهارات التفكير المنطقي للعام الدراسي(2015- 2016)م, ولتحقيق ذلك تم استخدام المنهج الوصفي التحليلي (تحليل محتوى) لملاءمته لطبيعة هدف البحث, وتم اعداد أداة البحث بالأعتماد على قائمة مهارات التفكير المنطقي بعد مراجعة الأدبيات والدراسات السابقة, وتم عرضها على مجموعة من المحكمين المتخصصين في المناهج وطرائق التدريس وعلم النفس وعلم الحاسبات والقياس
... Show MoreTrickle irrigation is a system for supplying filtered water and fertilizer directly into the soil and water and it is allowed to dissipate under low pressure in an exact predetermined pattern. An equation to estimate the wetted area of unsaturated soil with water uptake by roots is simulated numerically using the HYDRUS-2D/3D software. In this paper, two soil types, which were different in saturated hydraulic conductivity were used with two types of crops tomato and corn, different values of emitter discharge and initial volumetric soil moisture content were assumed. It was assumed that the water uptake by roots was presented as a continuous sink function and it was introduced into Richard's equation in the unsaturated z
... Show MoreLaser is a powerful device that has a wide range of applications in fields ranging from materials science and manufacturing to medicine and fibre optic communications. One remarkable
The insulation system of a machine coil includes several layers made of materials with different characteristics. The effective insulation design of machine coils, especially in the machine end winding, depends upon an accurate model of the stress grading system. This paper proposes a modeling approach to predict the transient overvoltage, electric field, and heat generation in machine coils with a stress grading system, considering the variation of physical properties in the insulation layers. A non-uniform line model is used to divide the coil in different segments based on material properties and lengths: overhang, stress grading and slot. The cascaded connection of chain matrices is used to connect segments for the representation of the
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