Enhanced experimental investigation of threshold determination for efficient channel detection in 2.4 GHz WLAN cognitive radio networks

This paper presents an experimental investigation of threshold determination for efficient channel detection in wireless LAN (WLAN) based cognitive radio (CR) networks. The spectrum saturation problem is a critical issue in wireless communication systems worldwide due to on growing user demands day by day with many new applications to the limited frequency spectrum. Hence, present demand is an efficient and intelligent spectrum management and allocation system. In this paper, we proposed an adaptive threshold determination technique based on free space path loss (FSPL) model to detect the presence or absence of PUs. The model is designed especially for Android based smartphones and tablets. The smartphones act as secondary users (SUs) and existing 2.4 GHz WLAN channels as PUs. The network is prepared in a usual noisy lab/outdoor environment and tested for the robustness of the proposed model. Results show the desired range of usable threshold and the channel detection performance depends on the noise floor level of the surrounding environment

Assessment of Water Quality Parameters in Karnafuli River: A Case Study in Karnafuli Paper Mill Area

Karnafuli River is the largest and important river, located in port city Chittagong of Bangladesh. Karnafully paper mill is situated in the embankment of this river and dependent for water supply. This study has been conducted in river basin area near to this paper mill to assess the important water quality parameters specifically pH, Turbidity, TDS, Temperature and Dissolved Oxygen (DO). There are three sampling locations consisting of upstream, middle stream and downstream at the 100 meter distance from each other were been selected for analysis. The study found the pH, turbidity, TDS, Temperature and DO values in upstream are 5.5, 36 NTU, 300 ppm, 32 0C and 5.6 mg/l whereas middle stream values are 5.2, 37.2 NTU, 1021 ppm, 34 0C and 4.2 mg/l and downstream values are 5.4, 36 NTU, 751 ppm, 32.3 0C and 4.8 mg/l respectively. Analyzed data has shown that the quality of discharge water are beyond of Bangladesh national standard and contaminating with river water causing for adverse impacts on surrounding aquatic environment. The finding, hereby arguing to treat effluent before discharge into the river and the people and the government should be sincere for reducing this river pollution

Heritage studies and measured drawings of Masjid Jamek Sultan Abdul Samad, Kuala Lumpur

Masjid Jamek Sultan Abdul Samad was built in 1909 following the demolition of Masjid Kampung Rawa that is located at Java Street (Jalan Tun Perak) due to expansion of road and to carter the increasing number of Jemaah. The masjid was one of the earliest mosques in Kuala Lumpur. The establishment of Kuala Lumpur is always closely related to Masjid Jamek Sultan Abdul Samad. Furthermore, the quaint masjid is located at the confluence of Klang River and Gombak River, which gives Kuala Lumpur its name. The masjid has gone through a few renovations to cater for the needs of the worshippers. Besides, to pay respect to the third Sultan of Selangor, Almarhum Sultan Abdul Samad, the masjid has been renamed from Masjid Jamek Kuala Lumpur to its current name, Masjid Jamek Sultan Abdul Samad. This report material is separated into (two) 2 parts. The first part of the report highlights the literature review and the findings of Masjid Jamek Sultan Abdul Samad from the fieldwork. It focusses on the contextual studies, the colonial influences, the background history, the details of building construction and case studies from buildings with similar architectural elements. Meanwhile, the second part of this report comprise a compilation of measured drawings of Masjid Jamek Sultan Abdul Samad in 2D and 3D. This report is to convey the analytical studies of the part of Masjid Jamek history and chronology, architectural influences, and the site context of the masjid, and how the structure affect the surrounding context, the culture, the society and the economy activities of Kuala Lumpur until this day. Hopefully, these studies can be beneficial and better enhancement to others in term of its architectural and historical data. Therefore, it is important for the next generation to come appreciate the past story amid the rapid growth and advancement of Kuala Lumpur