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

HUBUNGAN ANTARA KADAR GULA DARAH SEWAKTU DENGAN DISFUNGSI EKSEKUSI PADA CEDERA KEPALA

Pendahuluan: Cedera Kepala merupakan masalah kesehatan masyarakat global, sebagian besar disebabkan oleh kecelakaan lalu lintas. Mayoritas penelitian cedera kepala berfokus pada keluaran motorik, komplikasi dan kematian. Masih sedikit informasi mengenai disfungsi eksekutif dalam hubungan dengan kadar glukosa darah pada kasus cedera kepala. Penelitian ini bertujuan untuk menganalisis hubungan antara kadar glukosa darah sewaktu dengan kejadian disfungsi eksekutif pada pasien cedera kepala akut. Metode: Penelitian di disain potong lintang berbasis rumah sakit yang dilakukan selama 6 bulan di instalasi gawat darurat (IGD) RSUP Prof. R. D. Kandou. Populasi penelitian adalah seluruh pasien cedera kepala/CK yang dirawat pada fase akut. Sampel penelitian didapatkan sebanyak 76 orang setelah memenuhi kriteria penyertaan. Disglikemia bila kadar GDS dibawah 80 mg/dl (hipoglikemia) atau diatas 200 mg/dl (hiperglikemia). Disfungsi eksekutif jika didapatkan nilai diluar normal pada tes TMT-A dan B. Dilakukan analisis data univariat dan bivariat. Hubungan antar variabel dianalisis dengan uji chi square dan analisis odd ratio menggunakan perangkat lunak SPSS. Batas kemaknaan ditetapkan jika p<0,05. Hasil: Mayoritas cedera kepala terjadi pada laki-laki (80,3%). Usia dibawah 21 tahun merupakan segmen yang terbanyak (31,6%). Onset sampai 3 jam sejak kejadian saat tiba di RS sebesar 38,2%. Gejala penurunan kesadaran sebesar 65,8%. Sebagian besar kasus tergolong cedera kepala ringan (65,8%). Proporsi kejadian disglikemia adalah 3,9%. Proporsi gangguan fungsi eksekutif adalah sebesar 28,9%. Pada kelompok disglikemia didapatkan proporsi disfungsi eksekutif sebesar 33,3%, sedangkan pada non-disglikemia sebesar 28,8%. Pada uji statistik didapatkan OR 1,23 (95% CI 0,10 – 14,39), p=0,86. Simpulan: Tidak didapatkan hubungan bermakna antara kadar glukosa darah sewaktu dengan kejadian disfungsi eksekutif pada cedera kepala akut.Kata kunci: Kadar Glukosa Darah, Disfungsi Eksekutif, Cedera KepalaABSTRACTIntroduction: Head injury is a global public health problem, commonly due to traffic accidents. Researches on head injury are mostly focused on motoric outcome, complication and mortality. There is lack of study about executive dysfunction among the victims, especially in relationship to blood glucose level. The objective of this study was to analyze the association between random blood glucose level and executive dysfunction in acute head trauma. Method: This was a hospital-based cross-sectional study for a-six-months period of research at local provincial tertiary hospital. Study population were head injury patients admitted to hospital in acute phase. We recruited consecutively 76 samples based on specific inclusion criteria. Dysglycemia was defined as random blood glucose was below 80 mg/dl (hypoglycemia) or above 200 mg/dl (hyperglycemia). Executive dysfunction was defined as abnormal score on TMT-A and B. We applied Chi square with Odd Ratio (OR) analysis to reach statistical conclusion. P-value less than 0,05 were significant. Result: Most of the patients were male (80,3%). Majority of cases were in group age of less than 21 years old (31,6%). Almost half of the patients (38,2%) were reach hospital within 3 hours after the accident. Most of them with unconsciousness as chief complaint (65,8%). Mild head injury were 65,8% of all cases. We found proportion of dysglycemia was 3,9%. Executive dysfunction was 28,9%. Among dysglycemic patients, we found the proportion of executive dysfunction was 33,3%, while in non-dysglycemia group executive dysfunction was 28,8%. In statistical analysis, we found OR 1,23 (95% CI 0,10 – 14,39), p = 0,86. Conclusion: There was no significant association between blood glucose level and executive dysfunction among head injury due to traffic accidents.Keywords: Executive Dysfunction, Dysglycemia, Glucose Level, Head Traum

High performance mixed optical CDMA system using ZCC code and multiband OFDM

In this paper, we have proposed a high performance network design, which is based on mixed optical Code Division Multiple Access (CDMA) system using Zero Cross Correlation (ZCC) code and multiband Orthogonal Frequency Division Multiplexing (OFDM) called catenated OFDM. In addition, we also investigate the related changing parameters such as; effective power, number of user, number of band, code length and code weight. Then we theoretically analyzed the system performance comprehensively while considering up to five OFDM bands. The feasibility of the proposed system architecture is verified via the numerical analysis. The research results demonstrated that our developed modulation solution can significantly enhanced the total number of user; improving up to 80% for five catenated bands compared to traditional optical CDMA system, with the code length equals to 80, transmitted at 622 Mbps. It is also demonstrated that the BER performance strongly depends on number of weight, especially with less number of users. As the number of weight increases, the BER performance is better

Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark

During the fishing process, fish react to a trawl with a series of behaviours that often are species and size specific. Thus, a thorough understanding of fish behaviour in relation to fishing gear and a scientific understanding of the ability of different gear designs to utilize or stimulate various behavioural patterns during the catching process are essential for developing more efficient, selective, and environmentally friendly trawls. Although many behavioural studies using optical and acoustic observation systems have been conducted, harsh observation conditions on the fishing grounds often hamper the ability to directly observe fish behaviour in relation to fishing gear. As an alternative to optical and acoustic methods, we developed and applied a new mathematical model to catch data to extract detailed and quantitative information about species- and size-dependent escape behaviour in towed fishing gear such as trawls. We used catch comparison data collected with a twin trawl setup; the only difference between the two trawls was that a 12 m long upper section was replaced with 800 mm diamond meshes in one of them. We investigated the length-based escape behaviour of cod (Gadus morhua), haddock (Melanogrammus aeglefinus), saithe (Pollachius virens), witch flounder (Glyptocephalus cynoglossus), and lemon sole (Microstomus kitt) and quantified the extent to which behavioural responses set limits for the large mesh panel's selective efficiency. Around 85% of saithe, 80% of haddock, 44% of witch flounder, 55% of lemon sole, and 55% of cod (below 68 cm) contacted the large mesh panel and escaped. We also demonstrated the need to account for potential selectivity in the trawl body, as it can bias the assessment of length-based escape behaviour. Our indirect assessment of fish behaviour was in agreement with the direct observations made for the same species in a similar section of the trawl body reported in the literature

High performance mixed optical CDMA system using ZCC code and multiband OFDM

In this paper, we have proposed a high performance network design, which is based on mixed optical Code Division Multiple Access (CDMA) system using Zero Cross Correlation (ZCC) code and multiband Orthogonal Frequency Division Multiplexing (OFDM) called catenated OFDM. In addition, we also investigate the related changing parameters such as; effective power, number of user, number of band, code length and code weight. Then we theoretically analyzed the system performance comprehensively while considering up to five OFDM bands. The feasibility of the proposed system architecture is verified via the numerical analysis. The research results demonstrated that our developed modulation solution can significantly enhanced the total number of user; improving up to 80% for five catenated bands compared to traditional optical CDMA system, with the code length equals to 80, transmitted at 622 Mbps. It is also demonstrated that the BER performance strongly depends on number of weight, especially with less number of users. As the number of weight increases, the BER performance is better

High performance mixed optical CDMA system using ZCC code and multiband OFDM

In this paper, we have proposed a high performance network design, which is based on mixed optical Code Division Multiple Access (CDMA) system using Zero Cross Correlation (ZCC) code and multiband Orthogonal Frequency Division Multiplexing (OFDM) called catenated OFDM. In addition, we also investigate the related changing parameters such as; effective power, number of user, number of band, code length and code weight. Then we theoretically analyzed the system performance comprehensively while considering up to five OFDM bands. The feasibility of the proposed system architecture is verified via the numerical analysis. The research results demonstrated that our developed modulation solution can significantly enhanced the total number of user; improving up to 80% for five catenated bands compared to traditional optical CDMA system, with the code length equals to 80, transmitted at 622 Mbps. It is also demonstrated that the BER performance strongly depends on number of weight, especially with less number of users. As the number of weight increases, the BER performance is better

New catenated OFDM modulation scheme in zero cross correlation OCDMA at various number of user and effective power

This paper proposes an integration of optical Code Division Multiple Access (OCDMA) with new catenated Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme. This effective combination based on Zero Cross Correlation (ZCC) code can enhanced the system capacity and increased spectral efficiency by fully utilizing the available electrical bandwidth. We investigate the performance of the proposed system for various number of user, number of weight and effective power. The performance assessment is carried out by means of the signal to noise ratio (SNR) and bit error rate (BER) for up to five catenated OFDM bands transmitted simultaneously through optical link at 622 Mbps. More specifically, mathematical expressions for SNR and BER performance are derived. The corresponding numerical results are presented and compared with traditional OCDMA-ZCC system to verified the feasibility of the proposed system. The results show that with OCDMA/catenated-OFDM based on ZCC code provides 86% more number of permissible user for SNR of 15 dB. In addition, this integration provides higher receiver sensitivity; an approximately –22.5 dBm for 20 number of user with 8 number of weight. It is also found that, to accommodate more user, the system requires higher effective power at the receiver

New catenated OFDM modulation scheme in zero cross correlation OCDMA at various number of user and effective power

This paper proposes an integration of optical Code Division Multiple Access (OCDMA) with new catenated Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme. This effective combination based on Zero Cross Correlation (ZCC) code can enhanced the system capacity and increased spectral efficiency by fully utilizing the available electrical bandwidth. We investigate the performance of the proposed system for various number of user, number of weight and effective power. The performance assessment is carried out by means of the signal to noise ratio (SNR) and bit error rate (BER) for up to five catenated OFDM bands transmitted simultaneously through optical link at 622 Mbps. More specifically, mathematical expressions for SNR and BER performance are derived. The corresponding numerical results are presented and compared with traditional OCDMA-ZCC system to verified the feasibility of the proposed system. The results show that with OCDMA/catenated-OFDM based on ZCC code provides 86% more number of permissible user for SNR of 15 dB. In addition, this integration provides higher receiver sensitivity; an approximately –22.5 dBm for 20 number of user with 8 number of weight. It is also found that, to accommodate more user, the system requires higher effective power at the receiver