127 research outputs found

    Evaluasi Sistem Manajemen K3 Terhadap Metode Pemancangan Jack-in Pile

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    Pekerjaan Pekerjaan pondasi menggunakan metode jack-in pile sering kali menjadi pilihan pada proyek-proyek konstruksi di Surabaya. Meskipun lebih praktis dibandingkan metode lain, metode ini tetap menggunakan banyak alat berat sehingga kontraktor perlu memperhatikan penerapan peraturan untuk keselamatan para pekerjanya. Penelitian ini bertujuan untuk mengetahui apakah sistem manajemen K3 yang telah diterapkan oleh Perusahaan-Perusahaan kontraktor pemancangan sudah sesuai dengan peraturan yang ada atau tidak, serta mengetahui faktor-faktor yang memungkinkan terjadinya kecelakaan kerja. Dari hasil 2 metode penelitian yang dilakukan, didapatkan hasil yang cukup berbeda. Hasil wawancara tidak sesuai dengan hasil observasi di lapangan. Persentase penerapan yang mencapai 87,5% pada saat wawancara ternyata berbeda jauh dengan Kenyataannya yang hanya mencapai persentase 53,85%. Dari hasil ini dapat disimpulkan bahwa belum semua sistem manajemen K3 yang direncanakan oleh Perusahaan-Perusahaan kontraktor pemancangan diaplikasikan dengan baik di lapangan. Perusahaan tidak pernah menyediakan rambu-rambu K3 yang menyebabkan kesadaran yang rendah dari para pekerjanya untuk mentaati peraturan-peraturan, sebagai contoh, pekerja yang menggunakan helm hanya 38%, operator yang menggunakan pelindung kepala hanya 25%, kebersihan dan ketertiban di proyek masih sangat buruk

    Penentuan Aktivitas Antioksidan Berdasarkan Nilai IC50 Ekstrak Metanol Dan Fraksi Hasil Partisinya Pada Kulit Biji Pinang Yaki (Areca Vestiaria Giseke)

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    Tujuan dari penelitian ini adalah untuk menentukan nilai IC50 ekstrak metanol dan hasil partisinya dari ekstrak Areca vestiaria Giseke. Penelitian dimulai dengan proses maserasi menggunakan pelarut metanol, kemudian dievaporasi pada suhu 40oC dan menghasilkan 27,3 g ekstrak pekat dari 330,2 g sampel. Selanjutnya, ekstrak metanol diuji aktivitas antioksidannya dan diperoleh nilai IC50 sebesar 8,3 ppm.. Ekstrak kemudian dipartisi dengan pelarut n-heksana, etil asetat dan air dan dievaporasi. Seluruh fraksi kemudian diuji aktivitas antioksidannya dan fraksi etil asetat menunjukkan aktivitas antioksidan yang paling baik dengan nilai IC50 sebesar 10,9 ppm.The purposes of this research were to determine the IC50 values from methanol extract and its extract partition of extract Areca vestiaria Giseke. The research was started with maceration process using methanol as a solvent, then evaporated at 40oC which produce 27,3 g extract from 330,2 g sample. After that, methanol extract was tested its antioxidant activity and the result of IC50 values ​​was 8,3 ppm. And then, the extract was partitioned with n-hexane, ethyl acetate and water and evaporated. All of the fraction was then tested its antioxidant activity. Ethyl acetate fraction showed the best antioxidant activity with IC50 values ​​of 10,9 ppm

    Deep Learning for Channel Estimation and Signal Detection in OFDM-Based Communication Systems

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    The goal of 6G communication networks requires higher transmission speeds, tremendous data processing, and low-latency communication. Orthogonal frequency-division multiplexing (OFDM), which is widely utilized in 5G communication systems, may be a viable alternative for 6G. It significantly reduces inter symbol interference (ISI) in the frequency-selective fading environment. Channel estimation is critical in OFDM to optimize system performance. Deep learning has been employed as an appealing alternative for channel estimation and signal detection in OFDM-based communication systems due to its better potential for feature learning and representation. In this study, we examine the deep neural network (DNN) layers created from long-short term memory (LSTM) for detecting the signals by learning the received signal as well as channel information. We investigate the performance of the system under various conditions. The simulation results show that the signal bit error (SER) is equivalent to and better than that of the minimum mean squared error (MMSE) and least square (LS) methods

    Measurement of the electric fluctuation spectrum of magnetohydrodynamic turbulence

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    Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be dissipated. Here we present the first measurements of the electric field fluctuation spectrum over the inertial and dissipative wavenumber ranges in a β1\beta \gtrsim 1 plasma. The k5/3k^{-5/3} inertial subrange is observed and agrees strikingly with the magnetic fluctuation spectrum; the wave phase speed in this regime is shown to be consistent with the Alfv\'en speed. At smaller wavelengths kρi1k \rho_i \geq 1 the electric spectrum is softer and is consistent with the expected dispersion relation of short-wavelength kinetic Alfv\'en waves. Kinetic Alfv\'en waves damp on the solar wind ions and electrons and may act to isotropize them. This effect may explain the fluid-like nature of the solar wind.Comment: submitted; 4 pages + 3 figure

    GA-Based Optimization for Multivariable Level Control System: A Case Study of Multi-Tank System

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    This paper presents a systematic way to determine the trade-off optimized controller tunings using computation optimization technique for both servo and regulatory controls of the Multi-Tank System, as one of the applications under the multivariable loop principle. The paper describes an improved way to obtain the best Proportional-Integral (PI) controller tunings in reducing the dependency on engineering knowledge, practical experiences and complex mathematical calculations. Relative Gain Array (RGA) calculation justified the degree of relation and the best pairing for both interacted control loops. Genetic Algorithm (GA), as one of the most prestigious techniques, was used to analyze the best controller tunings based on factor parameters of iterations, populations and mutation rates to the applied First Order plus Dead Time (FOPDT) models in the multivariable loop. Amid simulation analysis, GA analysis’s reliability was justified by comparing its performance with the Particle Swarm Optimization (PSO) analysis. The research outcome was visualized by generating the process responses from the LOOP-PRO’s multi-tank function, whereby the GA tunings’ responses were compared with the conventional tuning methods. In conclusion, the result exhibits that the GA optimization analysis has successfully demonstrated the most satisfactory performance for both servo and regulatory controls

    Using Community-Owned Resource Persons to Provide Early Diagnosis and Treatment and Estimate Malaria Burden at Community Level in North-Eastern Tanzania.

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    Although early diagnosis and prompt treatment is an important strategy for control of malaria, using fever to initiate presumptive treatment with expensive artemisinin combination therapy is a major challenge; particularly in areas with declining burden of malaria. This study was conducted using community-owned resource persons (CORPs) to provide early diagnosis and treatment of malaria, and collect data for estimation of malaria burden in four villages of Korogwe district, north-eastern Tanzania.In 2006, individuals with history of fever within 24 hours or fever (axillary temperature ≥37.5°C) at presentation were presumptively treated using sulphadoxine/pyrimethamine. Between 2007 and 2010, individuals aged five years and above, with positive rapid diagnostic tests (RDTs) were treated with artemether/lumefantrine (AL) while under-fives were treated irrespective of RDT results. Reduction in anti-malarial consumption was determined by comparing the number of cases that would have been presumptively treated and those that were actually treated based on RDTs results. Trends of malaria incidence and slide positivity rates were compared between lowlands and highlands. Of 15,729 cases attended, slide positivity rate was 20.4% and declined by >72.0% from 2008, reaching <10.0% from 2009 onwards; and the slide positivity rates were similar in lowlands and highlands from 2009 onwards. Cases with fever at presentation declined slightly, but remained at >40.0% in under-fives and >20.0% among individuals aged five years and above. With use of RDTs, cases treated with AL decreased from <58.0% in 2007 to <11.0% in 2010 and the numbers of adult courses saved were 3,284 and 1,591 in lowlands and highlands respectively. Malaria incidence declined consistently from 2008 onwards; and the highest incidence of malaria shifted from children aged <10 years to individuals aged 10-19 years from 2009. With basic training, supervision and RDTs, CORPs successfully provided early diagnosis and treatment and reduced consumption of anti-malarials. Progressively declining malaria incidence and slide positivity rates suggest that all fever cases should be tested with RDTs before treatment. Data collected by CORPs was used to plan phase 1b MSP3 malaria vaccine trial and will be used for monitoring and evaluation of different health interventions. The current situation indicates that there is a remarkable changing pattern of malaria and these areas might be moving from control to pre-elimination levels

    Exploiting LDPC Codes For Improving The Performance of Clipped-OFDM System

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    Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier transmission technique that becomes the best choice in wireless high-data-rate transmission. The drawbacks of OFDM are high Peak-to-Average Power Ratio (PAPR) and sensitivity to frequency offset. High PAPR decreases the amplifier’s efficiency. The simplest PAPR reduction method is clipping, but it gives in-band and out-of-band distortion that degrades the performance of the system. There are various types of clipping, such as classical clipping, deep clipping, and smooth clipping. This paper analyses the use of low-density parity-check (LDPC) codes as an error correction coding (ECC) for those various types of clipping. The simulation results show that classical clipping gives the best performance in PAPR reduction and error probability

    IMPLEMENTATION AND ANALYSIS OF THE INTERNET OF THINGS SYSTEM FOR ELECTRICAL ENERGY MONITORING AT INSTITUT TEKNOLOGI TELKOM PURWOKERTO

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    Measurement of electric power usage is carried out using simple measuring instruments and the recording is still manual so that the data obtained is not real-time and accurate. This research aims to implement an electrical energy monitoring system using the Internet of Things (IoT) to obtain real-time information related to electrical energy in the education industry. This research uses an Industrial Grade Power Meter to get a more accurate measurement value. To connect the Power Meter device with the IoT system, this research uses Modbus RS485 communication and a mini PC to process data from the meter, so that the data can be sent to a server using the MQTT communication protocol, and displayed on the Dashboard. The test results of this study indicate that the monitoring system can be implemented and the system runs well with end-to-end measurement results. From the measurement results, the current value (3 phase average) has an average deviation of 0.001 Amperes, Voltage (3 phase average) has an average deviation of 0.519 V, Power factor has an average deviation of 0.012, Active power has a deviation average of 0.000 kW, reactive power with an average deviation of 0.000 kVAR, apparent power with an average deviation of 0.000 kVA and frequency with an average deviation of 0.124 Hz. Then the MQTT protocol has a quality of service with index 4 based on TIPHON standardization on delay, throughput, and packet loss parameters, and index 3 based on TIPHON standardization on jitter parameters
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