Some Practical Guidelines for Effective Sample-Size Determination in Observational Studies

- The purpose of this present study was to determine the right sample size in observational study which is focusing on medical or health sciences field. Sample size calculation is actually depends on the type of how the study is designed. For example different formulas are used to calculate the sample size in different type of the study. In this article, the formula of single proportion and two proportions is discussed and an example from medical research, which may contribute to the understanding of this problem, is presented

Performance evaluation of VLC system using new modulation approach

We propose a modified OFDM modulation based on multiband scheme for visible light communications (VLC) system. The method called catenated-OFDM VLC system can efficiently boost the propagation distance and combat multipath induced the inter symbol interference and inter carrier interference. Design parameters such as number of optical bands, input power, distance and data rate are varied to see their effect on the system performances. Simulation analysis is done using Optisys software Ver. 11.0. The results show that the proposed system offers a good performance at longer transmission distance of 12 m for input power of 2 dBm in case of Band=3 with 10 Gbps data rate. BER curves also indicates that the proposed system can be operated at very high data rate of 15 Gbps. This exhibits the ability of the proposed system to be one of the candidate for future optical wireless communication system

Life cycle assessment (LCA) of particleboard: investigation of the environmental parameters

Particleboard is not entirely a wood replacement but a particular material with its properties, making it more effective at different times than heavy or solid wood. The world's biggest concern is environmental problems with formaldehyde as a particulate board binder that can lead to human carcinogenic agents. A cradle-to-gate life cycle assessment (LCA) of particleboard production was performed using openLCA software. The impact assessment was carried out according to the software's features. This preliminary investigation aims to analyze the chemical composition of particleboard and identify its environmental impact. The Fourier-transform infrared spectroscopy (FTIR) system was used to track the functional group of aliphatic hydrocarbons, inorganic phosphates, and main aliphatic alcohols found in particleboards made in Malaysia. Based on the FTIR results, aliphatic groups were found in numerous aggravates that the spectroscopic infrared was likely to experience. The most important vibrational modes were C-H, at approximately 3000 cm(-1), and -CH deformations around 1460 cm(-1) and 1380 cm(-1). Eight effect groups demonstrated that 100% of the input and all analyses produced the same relative outcome. The life cycle of a product is determined by pollution of the air, water, and soil. Thus, particleboard has a minimal impact on the environment, except for global warming

Kesan Pandemik Covid-19 terhadap Pelajar Universiti Utara Malaysia: Satu Tinjauan Pembelajaran dalam Talian

Makalah ini bertujuan untuk mengkaji kesan pandemik Covid-19 terhadap pelajar Universiti Utara Malaysia (UUM) khususnya berhubung pembelajaran dalam talian. Kajian ini melibatkan tiga aspek, iaitu sikap pelajar, persekitaran belajar dan keadaan belajar dalam talian. Seramai 100 pelajar ijazah sarjana muda yang terlibat sebagai responden dalam kajian ini. Kaedah borang kaji selidik Google Form digunakan dan diedarkan secara dalam talian kepada setiap responden. Analisis statistik deskriptif diaplikasikan untuk mendapatkan nilai kekerapan, peratusan dan min. Hasil kajian menunjukkan bahawa dari aspek sikap pelajar, kebanyakan pelajar menghadapi kesukaran untuk menguruskan masa belajar dengan baik. Manakala, dari aspek persekitaran belajar, kebanyakan pelajar menghadapi gangguan untuk fokus dalam pembelajaran disebabkan oleh tugasan di rumah. Dari aspek keadaan belajar dalam talian, kebanyakan pelajar didapati tertekan dengan tugasan yang diberikan secara dalam talian. Kajian ini dirujuk penting khususnya kepada pihak universiti supaya melaksanakan strategi yang holistik dalam membantu para pelajar mendepani kelangsungan pembelajaran dalam talian sepanjang pandemik