Performance enhancement of underwater propulsion motor using differential evolution optimization

1113-1119This paper describes the performance enhancement of underwater propulsion motor using differential evolution optimization (DEO). Usually during development stage, an analytical subdomain model (ASM) is often preferred to be used in the design of electric machines since ASM has faster computational time compared to the finite element method. differential evolution algorithm is deployed to provide the optimization process in searching the optimal motor parameters iteratively and intelligently with specific objective functions. For this purpose, a three-phase, 6-slot/4-pole permanent magnet synchronous motor (PMSM) intended for the underwater propulsion system is first designed by using ASM and then later optimized by differential evolution algorithm. Five main motor parameters, i.e., magnet pole arc, magnet thickness, air gap length, slot opening, and stator inner radius are varied and optimized to achieve the design objective functions, i.e., high motor efficiency, high output torque, low total harmonic distortion (THDv) in back-emf, and low cogging torque. Results from differential evolution optimization show an improved performance of the proposed PMSM where the efficiency of the motor is increased to 96.1% from its initial value of 94.2%, 13% increase in the output torque, and 4.1% reduction for total harmonic distortion in its back-emf. Therefore, DEO can be highly considered during initial design stage to optimize the motor parameters in developing a good underwater propulsion motor

Deformation Behaviour Analysis Of Car Wheel Rim Under Different Loading Using Finite Element Method

ABSTRACT An analysis was conducted to study the deformation behaviour of the car wheel rim when subjected to different loading. This design analysis was performed using SolidWorks and CATIA software. Steel and Alloy are the two types of car wheel rim commonly used in Malaysia. These car wheel rims have been modelled using SolidWorks and follow the manufacturer standard dimension and specification of the car wheel rims. CATIA runs the analysis of the rim models and supports the entire simulation on the rims. Analysis results are presented in the graph of maximum stress and maximum displacement versus speed. It has been found that the Steel wheel rim produced high stress value at 100 km/h speed or at 25 kN loading where the maximum stress is beyond the yield stress limit. Steel wheel rim also deformed twice than the Alloy wheel rim at 25 kN loading. This concludes the Steel wheel rim is highly absorbed loads which is not suitable for its application where the car wheel rim need to be moderately rigid and can withstand with the uneven road condition and potholes. This suggests that the Alloy wheel rim is safer than the Steel wheel rim when subjected to load

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Prescribing indicators at primary health care centers within the WHO African region: a systematic analysis (1995-2015)

Abstract Background Rational medicine use is essential to optimize quality of healthcare delivery and resource utilization. We aim to conduct a systematic review of changes in prescribing patterns in the WHO African region and comparison with WHO indicators in two time periods 1995–2005 and 2006–2015. Methods Systematic searches were conducted in PubMed, Scopus, Web of science, Africa-Wide Nipad, Africa Journals Online (AJOL), Google scholar and International Network for Rational Use of Drugs (INRUD) Bibliography databases to identify primary studies reporting prescribing indicators at primary healthcare centres (PHCs) in Africa. This was supplemented by a manual search of retrieved references. We assessed the quality of studies using a 14-point scoring system modified from the Downs and Black checklist with inclusions of recommendations in the WHO guidelines. Results Forty-three studies conducted in 11 African countries were included in the overall analysis. These studies presented prescribing indicators based on a total 141,323 patient encounters across 572 primary care facilities. The results of prescribing indicators were determined as follows; average number of medicines prescribed per patient encounter = 3.1 (IQR 2.3–4.8), percentage of medicines prescribed by generic name =68.0 % (IQR 55.4–80.3), Percentage of encounters with antibiotic prescribed =46.8 % (IQR 33.7–62.8), percentage of encounters with injection prescribed =25.0 % (IQR 18.7–39.5) and the percentage of medicines prescribed from essential medicines list =88.0 % (IQR 76.3–94.1). Prescribing indicators were generally worse in private compared with public facilities. Analysis of prescribing across two time points 1995–2005 and 2006–2015 showed no consistent trends. Conclusions Prescribing indicators for the African region deviate significantly from the WHO reference targets. Increased collaborative efforts are urgently needed to improve medicine prescribing practices in Africa with the aim of enhancing the optimal utilization of scarce resources and averting negative health consequences

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Studi Kelengkapan dan Pengelolaan Sarana Prasarana Praktik Bengkel “Engine” Teknik Kendaraan Ringan serta Hasil Belajar Siswa Standar Kompetensi Service Engine & Komponennya di SMKN 1 Rejotangan Kabupaten Tulungagung

ABSTRAK   Jasin, Rezal, M. 2013. Studi Kelengkapan dan Pengelolaan Sarana Prasarana Praktik Bengkel “Engine” Teknik Kendaraan Ringan serta Hasil Belajar Siswa Standar Kompetensi Service Engine & Komponennya di SMKN 1 Rejotangan Kabupaten Tulungagung. Skripsi, Program Studi Pendidikan Teknik Otomotif, Jurusan Teknik Mesin, Fakultas Teknik, Universitas Negeri Malang. Pembimbing: (I) Drs. H. Sumarli, M.Pd, M.T  (II) Drs. Eddy Rudianto, M.Pd.,   Kata Kunci: Sarana Prasarana Praktik Bengkel, Pengelolaan Sarana Prasarana Praktik Bengkel, Hasil Belajar Standar Kompetensi Service Engine dan Komponennya. Keberhasilan program pendidikan melalui proses belajar mengajar akan semakin baik apabila ditunjang oleh tersedianya sarana prasarana pendidikan yang memadai disertai dengan pengelolaan yang optimal. Sarana prasarana yang memadai disertai dengan pengelolaan yang optimal akan membantu siswa dan guru dalam mencapai tujuan pembelajaran. Variabel dalam penelitian ini ialah: (1) Tingkat kelengkapan sarana prasarana praktik bengkel “engine”; (2) Tingkat pengelolaan sarana prasarana praktik bengkel “engine” dan (3) Hasil belajar siswa pada standar kompetensi service engine dan komponennya. Tujuan dari penelitian ini ialah untuk mengetahui tingkat kelengkapan dan pengelolaan sarana prasarana praktik bengkel engine serta hasil belajar siswa standar kompetensi service engine dan komponennya di SMKN 1 Rejotangan, penelitian ini merupakan jenis penelitian survey deskriptif dengan pendekatan kuantitatif. Peneliti menggunakan teknik observasi, angket atau kuesioer, dan angket tes untuk mengumpulkan data, dan dianalisis dengan statistik deskriptif. Populasi dalam penelitian ini terdiri dari populasi benda dan populasi manusia, populasi benda terdiri dari sarana prasarana praktik bengkel “engine”, populasi manusia terdiri dari siswa kelas XI TKR SMKN 1 Rejotangan sebanyak 144 siswa, dan diambil sampel 50 siswa. Hasil: (1) Tingkat kelengkapan sarana prasarana praktik bengkel “engine” SMKN 1 Rejotangan Kabupaten Tulungagung masuk dalam kategori lengkap dengan persentase rata-rata keseluruhan 51%; (2) Tingkat pengelolaan sarana prasarana praktik bengkel “engine” SMKN 1 Rejotangan Kabupaten Tulungagung masuk dalam kategori baik dengan perentase rata-rata ketercapaian 75%; (3) Hasil belajar siswa pada standar kompetensi service engine dan komponennya mendapatkan nilai yang memuaskan dengan rata-rata nilai 75.40. Kesimpulan : (1) Persentase rata-rata tingkat kelengkapan sarana prasarana praktik bengkel “engine” mencapai 51% dengan kategori lengkap yang sudah mengarah kestandar Badan Standar Nasional Pendidikan dalam Permendiknas No. 40 tahun 2008, ditandai dengan 42% keterlengkapan alat-alat khusus, 61% keterlengkapan alat ukur mekanik, 59% keterlengkapan alat ukur elektrik (tune-up tester), 57% keterlengkapan alat tangan, 34% keterlengkapan trainer object, 90% keterlengkapan perabot, 44% keterlengkapan bahan, 46% ketercapaian luas area kerja; (2) Persentase rata-rata tingkat pengelolaan sarana prasarana praktik bengkel “engine” mencapai 75% dengan kategori baik ditandai dengan 82% tingkat pengelolaan dari segi perencanaan, 75% tingkat pengelolaan dari segi pengorganisasian, 72% tingkat pengelolaan dari segi pergerakan dan 70% tingkat pengelolaan dari segi pengawasan; (3) Hasil belajar standar kompetensi perawatan engine dan komponennya mendapatkan nilai memuaskan dengan rata-rata 75.40, ditandainya dengan 28% siswa (14 dari 50 siswa) mendapatkan nilai cukup, 44% siswa (22 dari 50 siswa) mendapatkan nilai baik dan 8% siswa (4 dari 50 siswa) mendapatkan nilai sangat baik. Saran: (1) Bagi dinas pendidikan dan kebudayaan kabupaten tulungagung hendaknya dapat menjadikan hasil penelitian sebagai acuan serta bahan pertimbangan untuk dapat memfasilitasi sekolah dalam hal pengadaan sarana prasarana serta memberikan pelatihan mengenai pengelolaan bengkel; (2) Bagi sekolah hendaknya selalu meningkatkan kualitas penyediaan atau pengadaan sarana prasarana praktik yang ada disekolah dalam usaha untuk mencapai tingkat keterlengkapan yang lebih baik lagi; (3) Bagi guru hendaknya ikut berperan aktif dalam menditeksi kelengkapan sarana prasarana praktik dan lebih memfokuskan pengawasan pada proses pembelajaran praktik sehingga hasil belajar siswa yang optimal dapat terpenuhi, (4) bagi peneliti selanjutnya, sebagai acuan dalam pengembangan penelitian dalam penelitian selanjutnya

High voltage magnetic pulse generation using capacitor discharge technique

A high voltage magnetic pulse is designed by applying an electrical pulse to the coil. Capacitor banks are developed to generate the pulse current. Switching circuit consisting of Double Pole Double Throw (DPDT) switches, thyristor, and triggering circuit is developed and tested. The coil current is measured using a Hall-effect current sensor. The magnetic pulse generated is measured and tabulated in a graph. Simulation using Finite Element Method Magnetics (FEMM) is done to compare the results obtained between experiment and simulation. Results show that increasing the capacitance of the capacitor bank will increase the output voltage. This technology can be applied to areas such as medical equipment, measurement instrument, and military equipment

A new direction in utilization of chaotic fractal functions for cryptosystems.

Ever since Baptista in 1998 introduced his cryptographic scheme utilizing the only in online version. ergodic property of chaotic maps which is able to produce different cipher values for the same plaintext within the same message, intense scrutiny has been given upon the design. The capability to do the above mentioned output is akin to the Vigenere cipher and thus has the capacity to render an attacker with infinitely many choices (theoretically speaking) or in cryptographic terms would render an attacker to have a set off possible ciphertexts that could all have the possibility to just be mapped to a unique plaintext. This makes it computationally infeasible for the attacker to re-construct the correct plaintext. The Baptista design has been attacked and repaired many times. Alvarez noticed the characteristic of the cryptosystem that generates a sequence which can be exploited by an attacker. The attack which is dubbed the one-time pad attack is akin to an attack upon a One-Time-Pad (OTP) cryptosystem that reuses its key. Since then, attempts were made to redefine the cryptosystem such that it would be resistant towards the attack. Most of the attempts failed due to either the repaired cryptosystem still generates an exploitable sequence or it is not invertible. In this work we pair the Baptista design with a concept taken from the Iterated Function Systems (IFS). Although we did not encompass the whole concept of iterating the IFS, it could be seen that this could be easily done with the same desirable results. Four main outcomes are discussed. Beginning with the discussion on the infeasibility of Alvarez’s one-time pad attack on the design, we then discuss the quantitative properties of the design in discussing its cryptographic properties namely the Maximum Deviation Factor (MDF), Correlation Coefficient Factor (CCF) and the Strict Avalanche Criterion (SAC). Each experimental result shows promising results for this new design