ANALISIS VARIASI JUMLAH ANTENA TERHADAP UNJUK KERJA SISTEM ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) MULTIPLE INPUT MULTIPLE OUTPUT (MIMO)

OFDM is a transmission technique using orthogonal multi-carrier which can save bandwidth. While MIMO is a technique of using more than one antenna for transmitting and receiving. This can increase data transmission capacity without increasing bandwidth. In this study, an analysis of variations MIMO antennas 2x2, 2x4, 4x2, and 4x4 was carried out to determine the effect of antenna variations on OFDM MIMO performance. The modulation are BPSK and QPSK with frequency selective fading and AWGN channels. Performance parameters are Bit error rate (BER) versus Energy Bit per Noise (Eb/No), Power to Average Peak Ratio (PAPR), and eye diagram. The model simulated using a simulink with a number of input 100,000 bits. The results showed that BER performance compared to Eb/No, in MIMO 2x4 and 4x4 produced better performance than MIMO 2x2 and 4x2. With many receiving antennas, it gets a better signal which can reduce the occurrence of errors. Meanwhile, in PAPR parameter, 4x2 and 4x4 MIMO produce higher PAPR values than 2x2 and 2x4 MIMO. With the number of antennas, the PAPR value is distributed over all antennas and increase the PAPR value in the system. In the eye diagram parameters, the greater the Eb/No value, make a better eye diagram

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially