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The performance of the OCDMA systems is governed by numerous quantitative parameters such as the data rate, simultaneous number of users, the powers of transmitter and receiver, and the type of codes. This paper analyzes the performance of the OCDMA system using OFDM technique to enhance the channel data rate, to save power and increase the number of user of OSCDMA systems compared with previous hybrid subcarrier multiplexing/optical spectrum code division multiplexing (SCM/OSCDM) system. The average received signal to noise ratio (SNR) with the nonlinearity of subcarriers is derived. The theoretical results have been evaluated based on BER and number of users as well as amount of power saved. The proposed system gave better performance and save around −6 dBm of the power as well as increase the number of users twice compare to SCM/OCDMA system. In addition it is robust against interference and much more spectrally efficient than SCM/OCDMA system. The system was designed based on Flexible Cross Correlation (FCC) code which is easier construction, less complexity of encoder/decoder design and flexible in-phase cross-correlation for uncomplicated to implement using Fiber Bragg Gratings (FBGs) for the OCDMA systems for any number of users and weights. The OCDMA–FCC_OFDM improves the number of users (cardinality) 108% compare to SCM/ODCMA–FCC system.

In distillation process, density sensor that can overcome the flow rate is very important. This paper represents design and implementation of density sensor with flow rate as a disturbance. The fluid density experiments were carried out using several mixtures of alcohol and water that flew in various percentages. In this design, the density of the fluid is affected by the distance, the height displacement of the hydrometer is measured by the ultrasonic, and the ultrasonic oscillations are ± 1.5 mm which was caused by echo characteristics of the ultrasonic sensor. The problem has been solved with pulse-echo mode with 500 sampling data and 1 ms of sampling time, hence the ultrasonic reading is steady. When the height displacement is greater, the alcohol concentration in the water is higher. The correlation between the height displacements to concentration is non-linear. Various methods of relation model from a distance to concentration have been shown and compared. The best model was acquired by using power equation with a Root-Mean-Square-Error (RMSE), and the result was 2.945. The volume flow rate characteristic has been studied and considered in order to eliminate disruption to concentration readings. The Linear model approach was applied to avoid the influence of the volume flow rate with Root-Mean-Square-Error (RMSE), and the result was 1.095. Minimum flow rate is 0.2 L/m, and maximum flow rate is 0.75 L/m.

Introduction: Documentation of nursing care in Kalianget RSI in 2011 was totaled average 58,1% and in 2012 achieve was still low. According the lowest component was nursing diagnosis. This research aims to improve the performance of nursing care documentation based on knowledge management through the SECI Model’s concept in Garam Kalianget RSI Sumenep District.Method: Design of this research was action research. Population and sample in the research of knowledge, motivation and work responsibility were all nurses total ed 29 people. The dependent variable were knowledge, performance, motivation, work responsibility, and performance after intervention knowledge management (KM) and as independent variable in this research was knowledge, performance, and intervention research knowledge management in documentation nursing care. Data were collected by using questionnaires and checklists.Result: The results after the SECI model’s intervention and using Paired t Test with a 95% confidence level of knowledge obtained p = 0.0001 which means that there was a significant knowledge difference between before and after intervention, comparison of performance documenting of nursing care obtained value ρ = 0.004, which means there was a difference significant performance between before and after intervention. Comparison of SBAR effective communication performance values obtained ρ = 0.001, which means there was a significant performance difference between before and after intervention.Discussion: Knowledge management through SECI model’s has important role in improving performance documentation of nursing care and SBAR effective communication. It is recommended to do in forum sharing nurse’s experience or informant in practical communication in periodic, recording, documentation, and keep document well and doing supervision continously especially form nursing care and SBAR effective communication.

Orthogonal frequency division multiplexing (OFDM) is one of the Multi-Carrier Modulation (MCM) techniques that transmit signals through multiple carriers. These carriers (subcarriers) have different frequencies and they are orthogonal to each other. There are different parameters which alter the performance of OFDM system. In this paper, the effect of cyclic prefix length (CP) on optical (OFDM) system is investigated. Although employing a CP as the guard interval is a simple way to combat inter-symbol interference (ISI) and inter-carrier interference (ICI), it reduces the transmission efficiency of the system. The simulation results show the effect of CP length in power receiver, penalty of power and improved the performance based on signal to noise ratio (SNR). In addition, a tradeoff is needed between reduced interference effects and transmission efficiency.

Untuk menyusun jadwal kuliah bukanlah sesuatu yang mudah karena terkait aturan-aturan yang ada. Penjadwalan perkuliahan jika dilakukan dengan cara manual tentu saja akan memakan waktu cukup lama. Oleh karena itu pada penelitian ini mencoba untuk melakukan pendekatan menggunakan evolutionary algorithm untuk mempermudah dalam pembuatan jadwal kuliah dengan menerapkan aturan yang berlaku. Kromosom disusun dalam bentuk representasi string dengan susunan yang mewakili hari, jam perkuliahan, ruang dan gedung. Dari beberapa percobaan paremeter yang digunakan, diperoleh hasil optimal pada jumlah individu 100 dan peluang crossover sebesar 75%. Kata kunci : algoritma evolusi, algoritma genetik, penjadwalan mata kuliah. Abstract It is not an easy task to arange academic schedule because it is affected by many constraints. If this scheduling is done manually, it will consume many times. Therefore, this research tries to use the evolutionary algorithm approach to do schedulling by applying the applicable rules. Chromosomes are represented as string, which each of them consist of days, times, rooms, dan the buildings. From some experiments whisch are used in this research, optimal result obtained when use 100 individu in one population and 75% chance of crossover. Keywords : evolution algorithm, genetic algorithm, class scheduling

In this paper, we describe the improved performance of the SAC-OCDMA system using OFDM technique compared to SCM/SAC-OCDMA system. The theoretical results of proposed system shows that the new SAC/OCDMA system with OFDM technique provides better performance compared to SCM/OCDMA system based on multi diagonal code (MD), and the results have been evaluated based on BER and number of users for bit rate 1Gb/s and 10 Gb/s . Thus this system could be a promising solution to symmetric high capacity access networks with high spectral efficiency, cost effectiveness, good flexibility and enhanced security, which is candidate for next generation networks.

In this paper, we propose an alleviation interference scheme (AIS) for spectral amplitude coding (SAC) – optical code division multiple access (OCDMA) coding system approaches. The AIS SAC-OCDMA systems is demonstrated by utilizing the new flexible cross correlation (FCC) code. The FCC code has advantages, such as flexibility in-phase cross-correlation at any given number of users and weights, as well as effectively reduces the impacts of phase-induced intensity noise (PIIN) and has the multiple-access interference (MAI) cancelation property. The results indicated good performance whereas the FCC (W = 4, K = 150) AIS SAC-OCDMA coding system offers 66%, 172%, 650% and 900% percentage of cardinality enrichments as a contrast to DCS (W = 4, K = 90), MDW (W = 4, K = 55), MFH (W = 4, K = 20) and Hadamard (W = 8, K = 15) codes, respectively. Finally, the FCC AIS SAC-OCDMA coding system has low effective receive power Psr = −21 dBm which is expected to be more significant for future SAC-OCDMA coding systems without requiring any amplification at the receiving plant.

Explosive growth of bandwidth demand together with advance in latest communication services and emerging applications have inspired interest in optical code division multiple access (OCDMA). The work focuses on analysis and demonstration of two-dimensional (2-D) modified double weight (MDW) OCDMA wavelength-time. The 2-D MDW uses balance-detection for mitigating multiple access interference. The property of cross-correlation results in optimum phase induces intensity noise suppression (PIIN). The proposed code achieves high scalability; below 10-9 BER error floor the code cardinality reaches 254 simultaneous numbers of users which is double the 2-D PDC performance. The lowest effective power (Psr) for minimum optical transmission requirement for smallest number of users is achieved at-17.5dBm. The 2-D MDW OCDMA simulation model is developed to validate the realization of the code for BER and distance performance. The 2-D MDW OCDMA code successfully suppresses PIIN and mitigating MAI which result in high cardinality, reduce Psr and improved distance.

This paper investigates the performance of a spectral amplitude coding (SAC)–OCDMA system design utilizing subcarrier multiplexing techniques for use in the popular fiber-wireless (Fi-Wi) technology. Zero cross correlation code is employed because of its ability to eliminate phase induced intensity noise (PIIN) and the simplicity of using a direct detection technique at the receiving end. The performances are evaluated theoretically to derive the signal-to-noise ratio and results are presented in terms of bit error rates (BER). Results are analyzed to investigate the effect of code weight and variable data rates on the system performance. To validate the results, simulative analysis is also done using Optisys version 6.0. We demonstrated that the ZCC code performed better compared to other code for a BER floor of 10−9 with larger cardinality of subscribers. Results obviously indicate that system performance can be improved with larger code weight. In addition, the choice of lower bit rate is observed to perform better and more suitable for application in this hybrid Fi-Wi network.

A new two-dimensional (2-D) optical code division multiple access (OCDMA) scheme to increase the achievable system capacity is proposed. The code exhibits good cross-correlation property time and wavelength shift. Performances are analyzed on code size and correlation properties affecting two important system parameters, bit error rate (BER) as a function of cardinality generated and optical power transmission requirement. The proposed system can effectively suppress phase-induced intensity noise (PIIN) and has multi-access interference (MAI) cancellation property. Results in a good agreement indicate that 2-D modified double weight (MDW) offers 163.7% and 336.2% larger cardinality compare to 2-D perfect difference code (PDC) and 2-D modified quadratic congruence (MQC) code. By increasing spatial code (N) and keeps similar code length system performance can be further optimized. 2-D MDW (M = 45, N = 18) accommodates 252.2% and 18.3% cardinality increment and low effective transmitted power (Psr) at −17.9 dBm, compare to 2-D MDW (M = 247, N = 3) and (M = 84, N = 9) at 10−9 BER error floor. The architecture of the spectral/spatial MDW OCDMA system with property of MAI cancellation is presented.

A hybrid spectrally amplitude coded (SAC) optical code division multiple access (CDMA) with subcarrier multiplexing (SCM) scheme is a potential candidate for future broadband access solutions in the communication network. In this work, the performance of hybrid technique is investigated. Theoretical derivations are developed based on the zero cross correlation (ZCC) code. The performances are evaluated taking into account the relevant noises such as thermal noise, shot noise and inter modulation noise. Design parameters such as number of optical channels, number of subcarriers, and input power are varied to see their effect on the system performances. Simulation analysis using Optisys simulator is also done and compared to the numerical theoretical results. We measured the performance based on the merits of received power, input power and bit error rates of the received signals. Results revealed that power penalty due to increased number of channels in the hybrid system is lower compared to the conventional OCDMA system, and hence improving the system performance in term of power efficiency. This exhibits the ability of the hybrid system to be one powerful technique as a candidate for future access network. Key words: Spectral amplitude coding-optical code division multiple access (SAC-OCDMA), subcarrier multiplexing (SCM), zero cross correlation (ZCC), broadband access network.

In this paper, we show details of zero cross correlation (ZCC) code development and investigate performance by measuring bit-error-rates compared to other optical code division multiple access (OCDMA) codes using Avalanche photodiode (APD) and PIN photodetector. We present a configuration to determine how optical OCDMA systems can be applied with PIN and APD photodetector. Analysis of Avalanche photodiode gain optimization is discussed in ZCC code system. We also present analytical and numerical theoretical results for data transmission of spectrally encoded incoherent OCDMA signal and how signal-noise is being affected by using these two photodetectors.

This experiment aimed to know the effect of nitrifying bacteria and Chlorellasp. addition and different number of 3-dimensional cubical bamboo shelter in enhancing growth performance of Giant Freshwater Prawn (Macrobrachium rosenbergii de Man) during nursery phase in indoor system. During28 days of culture, treatment II (4 shelters addition~40% culture volume occupation) resulted in better prawn growth and culture performance compared to control (no shelter addition) (p

The use of minimal multiple access interference (MAI) in code design is investigated. Applying a projection and mapping techniques, a code that has a zero cross correlation (ZCC) between users in optical code division multiple access (OCDMA) is presented in this paper. The system is based on an incoherent light source—LED, spectral amplitude coding (SAC), and direct detection techniques at the receiver. Using power spectral density (PSD) function and Gaussian approximation, we obtain the signal-to-noise ratio (SNR) and the bit-error rate (BER) to measure the code performance. Making a comparison with other existing codes, e.g., Hadamard, MFH and MDW codes, we show that our code performs better at BER 10−9 in terms of number of simultaneous users. We also demonstrate the comparison between the theoretical and simulation analyses, where the results are close to one another.

Berbelanja adalah aktifitas yang menjadi pilihan wisatawan, peningkatan kunjungan wisatawan domestik dan mancanegara terutama dari Malaysia ke kota Bandung, mengisyaratkan perlunya pemahaman kecenderungan perilaku wisatawan sebagai konsumen dalam membeli produk atau berbelanja yang disebut gaya belanja. Dengan menggunakan sembilan gaya belanja yang dicetuskan Sproles dan Kendall (1986) studi komparasi antara kedua kelompok dilakukan, studi ini juga dapat disebut penelitian cross-culture. Hasil penelitian menunjukkan bahwa konsumen Indonesia dan Malaysia memiliki gaya belanja yang sama yaitu : perfectionistic, brand conscious, dan impulsive. Perbedaanya adalah konsumen Indonesia cenderung lebih bergaya belanja: price conscious, habitual, dan confused by over choice. Sedangkan konsumen Malaysia cenderung lebih bergaya belanja novelty conscious dan recreational . Pemahaman ini dapat dimanfaatkan pada pemasaran internasional terutama pada industri retail. Kata kunci : Konsumen, Gaya belanja, Studi Komparasi ABSTRAC T Shopping is one of most popular tourist activities. There is an increasing number of domestic and foreign tourists, especially from Malaysia visiting Bandung. It is valuable to understand the tourist’s behavior especially in their buying behavior which called shopping style. This study employed nine shopping styles from Sproles and Kendall (1986) which comparing domestic Indonesian and Malaysian tourist, this study can also be categorized as cross-culture research. The results show that Indonesian and Malaysian consumers have the same shopping style: perfectionistic, brand conscious, and impulsive. The difference is that Indonesian consumers tend to have shopping style: price conscious, habitual, and confused by over choice. While Malaysian consumers indicated to have shopping style: novelty conscious and recreational. This understanding can be utilized in international marketing, especially in the retail industry. Keywords: Customer, Shopping-style, Comparaive Study

Escherichia coli multidrug resistance protein E (EmrE) is a four transmembrane α-helix protein, and a member of the small multidrug resistance protein family that confers resistance to a broad range of quaternary cation compounds (QCC) via proton motive force. The multimeric states of EmrE protein during transport or ligand binding are variable and specific to the conditions of study. To explore EmrE multimerization further, EmrE extracted from E. coli membranes was solubilized in anionic detergent, sodium dodecyl sulphate (SDS), at varying protein concentrations. At low concentrations (≤ 1 μM) in SDS–EmrE is monomeric, but upon increasing EmrE concentration, a variety of multimeric states can be observed by SDS-Tricine polyacrylamide gel electrophoresis (PAGE). Addition of the (QCC), tetraphenyl phosphonium (TPP), to SDS–EmrE samples enhanced EmrE multimer formation using SDS-Tricine PAGE. The relative shapes of EmrE multimers in SDS with or without TPP addition were determined by small angle neutron scattering (SANS) analysis and revealed that EmrE dimers altered in conformation depending on the SDS concentration. SANS analysis also revealed that relative shapes of larger EmrE multimers (≥ 100 nm sizes) altered in the presence of TPP. Circular dichroism spectropolarimetry displayed no differences in secondary structure under the conditions studied. Fluorescence spectroscopy of SDS–EmrE protein demonstrated that aromatic residues, Trp and Tyr, are more susceptible to SDS concentration than TPP addition, but both residues exhibit enhanced quenching at high ligand concentrations. Hence, EmrE forms various multimers in SDS that are influenced by detergent concentration and TPP substrate addition.

Salah satu permasalahan yang dihadapi Sekolah Luar Biasa (SLB) yang ada di kota Semarang adalah sangat sedikitnya jumlah SLB yang menangani siswa tuna rungu dan sangat terbatasnya jumlah guru khusus untuk melatih berkomunikas bagi siswa berkebutuhan khusus tuna rungu. Dengan adanya ketidakseimbangan rasio guru dan siswa, dimana jumlah guru sangatlah sedikit dibanding dengan jumlah siswa berkebutuhan khusus tuna rungu, maka banyak siswa tidak dapat tertangani secara rutin dan berkelanjutan dalam belajar dan berlatih berkomunikasi menggunakan bahasa Indonesia. Selain hal tersebut, kegiatan melatih berkomunikasi membutuhkan waktu yang lama dan berkelanjutan, sehingga banyak guru dan siswa yang jenuh dan bosan dalam kegiatan tersebut. Perguruan Tinggi (PT) adalah salah satu lembaga yang diharapkan berperan aktif dalam proses terlaksananya transfer ilmu pengetahuan atau knowledge transfer kepada masyarakat luas dalam bentuk diseminasi hasil penelitian yang telah dilakukan. Pelatihan pembelajaran mandiri berkomunikasi untuk siswa tuna rungu menggunakan sistem aplikasi Text To Audio Visual Speech Bahasa Indonesia (IndoTTAVS) yang telah penulis kembangkan, bertujuan untuk mengatasi permasalahan terbatasnya jumlah SLB dan guru yang menangani siswa tuna rungu, mengatasi kejenuhan dan kebosanan dalam proses belajar mengajar serta mempercepat kemampuan berkomunikasi bagi siswa tersebut. Aplikasi IndoTTAVS adalah sebuah aplikasi yang dapat membangkitkan suara dengan visualisasi (audio-visual) dari text yang dimasukkan. Visualisasi yang dibangkitkan dari text masukan, berupa sebuah animasi dari bentuk mulut yang terdiri dari bibir, gigi dan lidah yang akan bergerak sesuai dengan suara yang dihasilkan. Siswa dapat belajar berkomunikasi dengan cara menirukan gerakan mulut (bibir, gigi dan lidah) untuk berlatih bicara sesuai text yang diinputkan. Pelatihan sudah dilakukan di SLB B Swadaya dan SLB B Widya Bhakti Semarang. Siswa berlatih untuk memahami apa yang diucapkan dengan membaca gerakan mulut bibir (lip-reading) dari aplikasi dan berlatih menirukannya. Sistem ini dapat digunakan secara mandiri oleh siswa dan dapat digunakan oleh guru sebagai alat bantu pembelajaran dalam kelas.

The two-year experience of teachingand redesigning a probability and statistics forengineers course at the Schulich School ofEngineering will be discussed through the lensof (i) writing and using a custom textbook forthe course and (ii) refocusing lectures onapplying concepts to solving problems. Thecourse redesign, for example, allows students todevelop conceptual and practical understandingon selecting the most appropriate probabilitydistribution for a given problem. The refocusingof lectures to problem solving proves very usefulfor students. Further textbook development isbriefly discussed.

Stress and displacement fields of a two-dimensional solid under plane strain are solved subject to surface reconstruction boundary conditions. The alternating lateral Dirac-δ forces at steps owing to the reconstruction obtained by Alerhand et al (1988 Phys. Rev. Lett. 61 1973–6) are recovered from the gradient of the stress field solution. Sinusoidal vertical and lateral displacements on a terrace are obtained, in addition to the vertical force distribution, in the direction normal to the surface. Reconstructed periodic terraces reduce their elastic energy by increasing their average width, but the elastic energy density reaches a finite limit with an increased terrace width. A like-oriented step–step interaction with the force dipole from the surface reconstruction, using the Marchenko–Parshin model, is considered and found to be repulsive. Reconstructed terraces of a vicinal surface are thermodynamically stable when the surface has a large dangling bond energy and a large miscut angle. Small miscut angle or small surface tension tends to destabilize the surface, although our result suggests that a multilayer configuration will metastabilize the terraces owing to the interface elastic mismatch.

A concise formula expressing the entropy of adatoms as a divergence of their flow due to diffusion and deposition flux is presented. Adatom-elastic strain interaction is provided by a canonical coupling between the diffusion flow and the deformation gradient of the strained layer. It is found that the zero of the free energy of an adatom-strained layer continuum system should be that of a coherent unstrained layer, thus necessarily neglecting the cohesive energy contribution, while for the adatom-unstrained continuum layer the zero corresponds to an equilibrium between the adatoms and free atoms, which involves the cohesive energy.

This paper presents the review of Double Weight (DW) codes family from perspective of codes evolution since beginning until now. First generation focuses on one-dimensional (1D) code which spreading has been carried out in time. Later, the second generation was introduced known as two-dimensional (2D) code where the encoding of data bit has spread in both wavelength and time domain. Codes construction and variety of detection techniques scheme used in DW codes family are also discussed. In this paper we focus on structure of among DW codes family as all the design of code sequence aim to eliminate Multiple Access Interference (MAI). Previous papers of DW codes family show a good quality of transmission and satisfactory the standard quality of Bit Error Rate (BER) above 10−9.

This paper analyzes the performance of the OS-CDMA system using OFDM technique to enhance the channel data rate, to save power and increase the number of user of OSCDMA systems. This system compared with previous hybrid subcarrier multiplexing/optical spectrum code division multiple-access (SCM/OSCDMA) system. The average received SNR with the nonlinearity of subcarriers is derived. The theoretical results have been evaluated based on BER and number of users as well as amount of power saved. The proposed system gave better performance and save around −6 dBm of the power as well as increase the number of users twice compare to SCM/OSCDMA system. In addition it is robust against interference and much more spectrally efficient than SCM/OSCDMA system. The system was designed based on Flexible Cross Correlation (FCC) code.

A new class of code called Flexible Cross-Correlation (FCC) for Spectral-Amplitude Coding Optical Code-Division Multiple-Access (SAC-OCDMA) systems has been de-veloped. The FCC code has advantages, such as flexible cross-correlation property at any given number of users and weights, as well as effectively reduces the impact of Phase-Induced Intensity Noise (PIIN) and Multiple-Access Interference (MAI) cancellation property. The results revealed that the FCC code can accommodate 150 users, where FCC code offers 66%, 172%, 650% and 900% improvement as a contrast to 90, 55, 20 and 15 numbers of users for Dynamic Cyclic Shift (DCS), Modified Double Weight (MDW), Modified Frequency Hoping (MFH) and Hadamard codes, respectively, for a permissible Bit Error Rate (BER) of 10−9 •

Various two-dimensional (2-D) OCDMA codes have been introduced in recent years due to their capabilities in enhancing cardinality, suppressing phase induced intensity noise (PIIN) and eliminates multiple access interference (MAI). This paper presents our new proposal of 2-D spectral/spatial Extended Enhanced Double Weight (2-D Extended-EDW) code. This code is designed to enhance cardinality and effective transmitted power. In other word, it effectively reduces noise and increasing simultaneous users. From our numerical analysis, we found that 2-D Extended-EDW code has a significantly better performance, in terms of the cardinality and effective transmitted power when compared with 2-D M-Matrices code.

The benefits of employing 2-Dimensional (2D) Wave-length/Time (W/T) Hybrid code to mitigate the optical noise in spectral amplitude coding OCDMA networks system is in-vestigated. This analysis allows us to identify the influences of optical noise such as PIIN noise, shot noise and thermal noise in the system performance by using 2D Hybrid FCC-MDW code. The mathematical calculation reveals this new code effectively mitigates the Phase Induced Intensity Noise (PIIN) and eliminates Multiple Access Interference (MAI). As a result, the performance of the system can be improved as well as support much more simultaneous users compared to 2D Perfect Difference (PD) and 2D M-matrices codes.

Two-dimensional Optical Code Division Multiple Access (2-D OCDMA) has gained great interest among researchers in optical communication systems. This work is aimed to present an alternative way of formulating the spectral/spatial incoherent two-dimensional Extended Enhanced Double Weight (2-D Extended-EDW) code. This code is proposed to suppress the phase induced intensity noise (PIIN) by using multiple access interference (MAI) cancellation property. The numerical analysis shows that 2-D EDW code has a better performance, in terms of bit error rate (BER) and the cardinality compared with one-dimensional Enhanced Double Weight (1-D EDW) code. In comparison with different combinations of spatial and spectral code length for 2-D Extended-EDW code, we found that by increasing the number of time chip, it significantly enhances the performance of the system.

A 2-Dimensional (2-D) Wavelength/Time (W/T) scheme is proposed for spectral amplitude coding OCDMA network system. The new hybrid codes are utilizing Flexible Cross Correlation (FCC) and Modified Double Weight (MDW) codes which both codes have good correlation properties and capable to suppress multiple access interference (MAI). From the numerical calculation, it has been shown that this new hybrid code effectively suppresses the phase Induced Intensity Noise (PIIN) and eliminates MAI. Furthermore, the cardinality of this proposed code accommodates 150% and 275% improvement compared to 2-D PD code and 2-D M-Matrices code respectively at the BER=10−9. As a result, the performance of the system can be improved as well as support much more simultaneous users compared to Perfect Difference (PD) and M-matrices codes.

Island size distributions of three-dimensional Si1−xGex/Si(001) islands of varying Ge fractions (x=0.4–0.7) and thicknesses grown by ultrahigh vacuum chemical vapor deposition are studied. Size distributions for percolating islands obey the dynamic scaling hypothesis due to a random percolation process, only in the small island limit. Island morphologies strongly suggest the presence of Smoluchowski ripening, in which islands collide and ripen. Random percolation and Smoluchowski ripening are thus combined to analyze the size distributions. To understand the critical behavior of the islands, as exhibited by their size distributions, a mean-field theory for coherently strained island formation is formulated, by incorporating surface energy and strain relaxation. The resulting phase diagram shows that island formation in Si1−xGex/Si(001) occurs near the critical region. Order parameter fluctuations can be estimated by calculating the curvature energy for such a system, showing that the strain fluctuations a...

The analysis realization performance of 2-dimensional (2-D) code OCDMA system with the AND Detection technique was investigated. Two codes of 2-D has been employed in this project for OCDMA system; the 2-D M-Matrices code and 2-D Hybrid code. The performance was analyzing using Opti-Sys software. During simulation process, various parameters varied such as distance of the fiber, bit rate, and number of users. The result indicates that 2-D Hybrid code system modulated at 155 mbps has produced lower bit error rate (BER) of 8.31×10-9 at 65 km for 9 users in comparison to 2-D M-Matrices code system which can only achieve the maximum transmission distance at 25 km with BER of 1.16×10-9. It shows that the 2-D Hybrid code has better phase induced intensity noise suppression in comparison to the 2-D M-Matrices code.

This experiment was aimed at finding out the effects of using nitrifying bacteria and Chlorella sp. and the application of a differing number of 3-dimensional cubical bamboo shelters for enhancing the growth performance of Giant Freshwater Prawns (Macrobrachium rosenbergii de Man) during the nursery phase in an indoor system. During 28 days of culture, treatment II (application of 4 shelters ~40% culture volume occupation) resulted in better prawn growth and culture performance compared to control (no shelter application) (p

In this paper, we propose a new design of Fiber-to-the-Home (FTTH) network based on Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA). The FTTH network based on SAC-OCDMA system is tested by employing the Dynamic Cyclic Shift (DCS) code. Whereas, the DCS code is selected due to reduced and mitigates the effect of Multi Access Interference (MAI) in comparing with existing SAC-OCDMA codes. The AND subtraction technique is employed at the at the receiver part of the FTTH network structure due to its compatibility with DCS code to suppress the effect of the MAI. The results, which are obtained mainly from experimental simulations, are presented. In the simulation analysis, the study focused on: the effect of distance, data rate, and noise power on system performance. Finally, Simulation results show that DCS code is expected to become more important in the future of the FTTH network environment.

In this paper, we demonstrate a novel architecture of variable weight Zero Cross Correlation code in the family of Spectral Amplitude Coding(SAC) Optical Code Division Multiple Access (OCDMA) to be utilized in the triple play services of OCDMA applications based on the end users demand and requirements. This is achieved by adapting multiple weights of Zero Cross Correlation (ZCC) code onto one system to accommodate different Quality of Service (QoS) requirements. The results are characterized by bit error rate (BER) and eye pattern simulated using OptiSystem software. Results proved a successful transmission of this scheme over 20km distance thus offering flexibility of independent QoS. It is also revealed that the performance is always better for users with larger number of code weight compared to those assigned with smaller code weight.

In this paper, an improvement of achievable system capacity Avalanche photodiode (APD) performance of spatial/spectral modified double weight (MDW) code for cardinality, bit error rates (BER) and noise interference is analyzed. The results in very good agreement indicate that 61% cardinality improvements compare to 2-D MDW code with PIN. The effective transmitted power (P sr ) for 2-D MDW-APD (M=135, N=3) improves by 8.5dBm at 10−9 error floor. At low gain BER value is mitigated through suppressing PIIN. Apparently, performance of the proposed system improves substantially with APD.

The wavelength-time modified double weight (MDW) optical division multiple access (OCDMA) scheme to reduce multiple access interference (MAI) and compensate bit error rate (BER) and phase-induced intensity noise (PIIN) in incoherent OCDMA systems is proposed. The analysis permits thorough understanding of PIIN, shot and thermal noises effect on 2-Dimensional (2-D) MDW OCDMA system performance. PIIN is the dominant noise factor in the OCDMA time-spreading scheme. The 2-D MDW code shows better tolerance to PIIN in comparison to others with enhanced system performance. We prove by numerical analysis that the PIIN is maximally suppressed by the proposed code through minimizing property of cross-correlation in comparison to the 2-D PDC and 2-D MQC OCDMA code.

This paper demonstrates a novel architecture of hybrid subcarrier multiplexing Wavelength Division Multiplexing network combining laser and light emitting diodes (LED) as the light sources. The performances are simulated using Optisys software and analyzed based on bit error rates (BER) and the eye pattern of the received signals. Results proved that the combination of the laser and LED light sources in one system can be considered an effective way to maximize system capacity and at the same time, reduce implementation cost of hybrid SCM WDM network architecture.

This paper presented the novel of optical code for Optical Code Division Multiple Access (OCDMA) system using Spectral Amplitude Coding. A new class of code, called Modified Non-Zero Cross Correlation Code (MNZCC). MNZCC code has minimum length, can be constructed easily for a given number of users, weights and any desired cross correlation (λmax). The MNZCC code was observed by OptiSys. 6.0 software. The MNZCC code has shown superior performance in term reducing the effect of MAI, with better bit error probability. The results obtain for the MNZCC were compared with others existing optical codes such as DW code.

This study was conducted to develop a zero water discharge technology for Macrobrachium rosenbergii growth in order to solve the unpredictability of prawn production during grow-out phase.The system consists of three major compartments: (1) Prawn culture tank, (2) Trickling biofilter for nitrification process, and (3) Textile vertical substrate for prawn territory expansion. The trial was conducted in three diferent stages: (1) nitrifying bacteria of 105 Colony Forming Units.mL-1(CFU.mL-1) was inoculated into the culture 24 hours prior to juvenile stocking and every 10 days during culture period, (2) the culture was grouped into five treatments: 30 individuals.m2 (control), 40 individuals.m2, 50 individuals.m2, 60 individuals.m2, and 70 individuals.m2, and (3) measurements of biological, physicochemical, and microbiological culture parameters. Optimum culture performance was obtained in the culture with initial stocking density of 30 individuals.m-2 (control) with final metabolic body weight, length, specific growth rate (SGR), survival rate (SR), feed conversion rate (FCR) of (11.37 ± 4.92) g, (10.69 ± 1.45) cm, 2.569%.day-1, 78.3%, and 0.99, respectively. However, from an economic perspective, stocking with 70 individuals.m-2 (treatment IV) produced the highest total final biomass (975 g) and highest profit (Rp. 19.285 per kg) compared to the other treatments. Results indicate that use of the developed zero-water discharge rearing system with the application of nitrifying bacteria and textile vertical substrate can maintain good water quality to support a higher stocking density, better growth and larval survival rate and profit of prawn M. rosenbergii de Man grow-out culture.

In this paper, the implementation of subcarrier multiplexing technique in spectral amplitude coding (SAC) optical code division multiple access (OCDMA) network using Zero Cross Correlation code is developed and investigated. Theoretical analysis is done to determine the signal-to-noise ratio of such network and analysis of the performances in term of bit error rates are presented. Simulations are done using Optisys software version 6.0. Motivation to this research is driven to take advantage of both the low implementation cost of the SCM technology which uses the existing RF/microwave devices; and the attractive SAC which reduce the Multiple Access Interference (MAI) in OCDMA system. The use of ZCC code can eradicate phase induced intensity noise (PUN) which will contribute to better BER. For typical error rate of optical communication system of 10e-9, it has been observed fro theoretical results that the new hybrid SCM/OCDMA system provide better spectral efficiency and accommodate more users simultaneously with less code length and thus lower cost of implementations than the traditional OCDMA network utilizing the ZCC code. Thus this system could be one promising solution to the symmetric high capacity access network with high spectral efficiency, cost effective, good flexibility and enhanced security, which makes an attractive candidate for next generation broadband access network

A new design code structure for Spectral Amplitude Coding with zero cross- correlation in Optical Code Division Multiple Access (OCDMA) has been proposed in this paper. The proposed code called Modified Zero Cross Correlation Code (MZCC). MZCC code provides much easier code construction, given any number of users K and weights to have minimum code length. MZCC code will be demonstrated using OptiSys 6.0. The results indicated that MZCC code is truly performs better in term of noise performance compared with existing Optical CDMA codes.

Efficiency of Rankine cycle as a function of working fluid molecule is modeled using the Redlich‐Kwong equation of state. We have evaluated 12 molecules, ranging from water to ethylene glycol, and have parameterized their individual performance on several material parameters, including heat capacity and compressibility. This research aims to understand at the molecular level what drives some molecules to perform better at certain temperature and pressure range of the Rankine cycle. Immediate applications we are interested in are geothermal power and solar thermal energy conversion.