541 research outputs found
Five-Phase Modular External Rotor PM Machines with Different Rotor Poles: A Comparative Simulation Study
The performance of fault-tolerant modular permanent magnet machines depends on the proper selection of the pole and slot numbers which result in negligible coupling between phases. The preferred slot and pole number combinations eliminate the effect of low-order harmonics in the stator magnetomotive force and thereby the vibration and stray loss are reduced. In this paper, three external rotor machines with identical machine dimensions are designed with different slots per phase per pole ratios. A simulation study is carried out using finite element analysis to compare the performance of the three machines in terms of machine torque density, ripple torque, core loss, and machine efficiency. A mathematical model based on the conventional-phase-model approach is also used for the comparative study. The simulation study is extended to depict machine performance under fault conditions
Supply Chain Management Model to Improve the Competitiveness of SMEs in the ASEAN Economic Community Era 2015–2025 in Tanjung Jabung Barat Regency, Indonesia
Creative industry is one of the economic sectors that is able to contribute directly to employment and to increase household income. In its journey, the creative industry is often difficult to grow well and has competitiveness even though it has good potential supported by the logistic of available raw materials that are the result of the natural resources of the local area. Furthermore, globalization and economic development is a process to create a single market in which logistics is an important tool in achieving competitive advantage by improving the quality of supply chain management as a facility to improve competitive advantage, especially in the era of ASEAN Economic Community (AEC). Supply chain management will improve innovation and other business approaches to provide positive results by improving service quality by reducing costs and efficiency of process and time. Hence, this study covered the development strategy of MSMEs in marine areas that have their own resources to be more competitive and become superior to the Indonesian market.
Keywords: strategy, competitiveness, MSMEs, supply chai
Analisis Kelembagaan Pengelolaan Daerah Penyangga Taman Nasional Kerinci Seblat: Studi Kasus Di Eks Hph PT Maju Jaya Raya Timber Kabupaten Bengkulu Utara Provinsi Bengkulu
Ex concession of PT Maju Jaya Raya Timber (PT MJRT) is located at North Bengkulu Regency, Bengkulu Province is an important buffer zone of Kerinci Seblat National Park (KSNP). Therefore the damage that happened in that area will have a huge impact in the on-going development of the reservation area. The purpose of this research is to design alternative policies to manage the buffer zone of KSNP. The analytical methods used are the Analytical Hierarchy Process (AHP) and SWOT analysis method are both used to design an alternative policies management. The result of this research showed that there have been changes in land cover, virgin forest only about 30%, and the rest was logged over area and has been converted to field crops owned by the locals and private company. This indicates that the management of ex-concession is not good enough. Based on Analytical Hierarchy Process and SWOT analysis, the prioritize function on the management of the area mentioned has be increasing to income of the locals, therefore this could decrease the pressure of the locals to take advantage in using the forest area. Some alternatives of policies which can be carried out is to strengthen property rights, developed local institution, developed the pattern of agroforestry and to upgrade the human resources by increasing the economic productivity for proper management of KSNP buffer zone
Optimasi Pola Tanam Usahatani Sayuran Selada dan Sawi di Daerah Produksi Padi (Studi Kasus di Desa Lam Seunong, Kecamatan Kota Baro, Kabupaten Aceh Besar)
. Farming is a plot of land or a part of the earth\u27s surface where the farmers and their families to grow crops or raise livestock. A farmer faced with the enigma to determining the competition of activity in optimizing farming activities. The research was done in Lam Seunong village, Kecamatan Kota Baro, Aceh Besar, the object of research is the farmers who worked in rice, mustard and lettuce land farm. The purpose of this research was to know optimal cropping pattern for mustard and lettuce farming in rice production areas in an effort to increase the optimize income of farmers. The research using purposive sampling techniques with particular sampling, analytical methods using linear programming optimization. The results showed the optimal cropping pattern in the local rice production area is rice and mustard greens in the first season and lettuce in the second season that will obtain maximum revenue of Rp. 76,568,940.00 per period of the rice planting season. With an area of arable land each season is 0.3 hectare for rice in the first season, 0.26 hectare for mustard in the first season, and 0.26 hectare for lettuce second season
Studying the effect of over-modulation on the output voltage of three-phase single-stage grid-connected boost inverter
AbstractVoltage boosting is very essential issue in renewable-energy fed applications. The classical two-stage power conversion process is typically used to interface the renewable energy sources to the grid. For better efficiency, single-stage inverters are recommended. In this paper, the performance of single-stage three-phase grid-connected boost inverter is investigated when its gain is extended by employing over-modulation technique. Using of over-modulation is compared with the employment of third order harmonic injection. The latter method can increase the inverter gain by 15% without distorting the inverter output voltage. The performance of extended gain grid-connected boost inverter is also tested during normal operation as well as in the presence of grid side disturbances. Simulation and experimental results are satisfactory
A family of discontinuous PWM strategies for quasi Z-source nine-switch inverters
This paper proposes a new family of discontinuous PWM strategies to control the quasi-Z-source nine-switch inverters (qZS-NSI). The presented strategies provide buck and boost inversion capabilities, and suitable for common-frequency and different-frequency modes of operation. Accordingly, two different shoot-through (ST) approaches are introduced and compared. The first approach uses three-leg ST, while the second uses single-leg ST to reduce the number of switching commutations, therefore minimizing switching losses. Both approaches can be implemented using simple-boost (SB) and maximum boost (MB) control methods. The operating principles, performance criteria, and PWM modulator of each scheme are introduced. Compared to the conventional PWM technique for the same output voltage gains, the proposed schemes ensure continuous input current with minimum ripples, and the voltage stresses on the switching devices and capacitors could be reduced in the proposed MB control schemes. Moreover, the effective switching frequency of upper and lower switches of all schemes is fixed and could be reduced by 1/3 from the switching frequency of the conventional technique of the qZS-NSI, while only the single-leg ST schemes ensure minimum effective switching frequency of the middle switches. The proposed modulation strategies are digitally implemented and tested on the LAUNCHXL-F28379D DSP. The feasibility of the proposed modulation schemes is confirmed via simulation and experimental results, which show good agreement with the theoretical analysis. Moreover, the presented strategies can be applied to other types of Z-source NSIs.Scopu
Mansai in the Marriage Tradition of the Banggai Ethnic in Central Sulawesi, Indonesia: A Living Sunnah Perspective
The Mansai tradition is the custom of collecting material assistance before the wedding to lighten the burden on the prospective groom. This procession becomes a problem whether it is in harmony with the Prophet's orders. This study is qualitative research using the approach of living traditions and anthropology of Islamic law. Living sunnah is used to analyze the concept of hadith that lives in the Banggai community, while the anthropology of Islamic law analyzes the practice of mansai which is a tradition in marriage. Data was collected by gathering information through in-depth interviews and literature studies. The field findings were then analyzed using the perspective of living sunnah and integrated with the customs of the people of the Banggai Tribe, Central Sulawesi. The selected hadiths are those that have been validated for the quality of their sanad and matan. This study found that the mansai tradition means that the prospective groom invites his family and community to bear the funds or assets as wedding expenses which will be handed over to the woman (mangantokon sai). Mansai as a custom has become a habit in accordance with Islamic law and has become a living sunnah. The main message in the Mansai tradition is to help each other and ease the burden on Muslim brothers and sisters in the process of marriage (banikah) in the Banggai Tribe community. Anthropologically, mansai as a tradition that has been accepted by the Banggai people for a long time, functions as a unifying medium, maintains the practice of deliberation and overcomes social problems
T cell activation markers “CD45RO and CD45RA”; neutrophil CD11b expression and soluble tumor necrosis factor receptor (p55) in early diagnosis of neonatal sepsis
Background: Neonatal sepsis is a common and life threatening disorder whose outcome and prognosis depend on early and efficient therapy. A sensitive and specific indicator at an early stage of the disease would certainly aid the early diagnosis of neonatal sepsis. Objective: We sought to investigate the diagnostic value of measuring the up-regulation of T-lymphocyte activation markers CD45RA/CD45RO, CD45RO, neutrophil CD11b expression, and soluble tumor necrosis factor receptor (P55) as tests for early detection of neonatal sepsis; as well as comparing them with the conventional methods of diagnosis. Methods: The subjects of this study comprised 39 neonates: 25 males (64%) and 14 females (36%). In addition to the clinical assessment, different laboratory investigations for the diagnosis of sepsis were done. These included a complete blood picture, quantitative measurement of C-reactive protein and blood and or CSF culture and sensitivity. Assays for T cell activation markers CD45RA/CD45RO and neutrophil CD11b by flow cytometry and soluble tumor necrosis factor receptor sTNFR1 by ELISA were carried out as well as chest plain x-raying. Results: The up-regulation of CD45RA/ CD45RO dual expression and CD45RO expression on T-lymphocytes was observed in the septic group. The percent expression of CD45RA/CD45RO and CD45RO was significantly elevated in the high-risk group when compared to the control group. However, CD45RA/CD45RO and CD45RO showed no significant difference in percent expression between the septic group and the high-risk group. CD11b expression was also significantly higher in the septic (72.8± 17.8) than the control group (17.2 ±9.9%, p < 0.05) and also in the high- risk group (42.2 ± 25.9%, p < 0.05) as compared to the control group. sTNFR55 was significantly high in septic group (18.14 ± 9.38 ng/ml) as well as in the high risk group (26.90 ± 16.89 ng/ml) when compared to the control group (6.44 ± 1.49 ng/ml, p < 0.05) with no significant difference between the former two groups (p > 0.05). In addition and according to the follow up sample taken after one week, a significant increase in the expression of CD45RO was realized in the septic group. Conclusion: The surface activation markers of T-lymphocytes (CD45RA/ CD45RO, CD45RO), neutrophil activation marker (CD11b) and soluble TNF receptor 1 are useful early indicators of neonatal sepsis, and are superior to the hematological scoring system and CRP in the early detection of the disease.Keywords: neonatal sepsis, surface activation markers, neutrophil activation marker, CD45RA/CD45RO, CD45RO, CD11b, soluble TNF receptor 1Egypt J Pediatr Allergy Immunol 2003; 1(2): 110-
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