polarization index
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2021 ◽  
Vol 12 ◽  
Author(s):  
Namkje Koudenburg ◽  
Henk A. L. Kiers ◽  
Yoshihisa Kashima

Opinion polarization is increasingly becoming an issue in today’s society, producing both unrest at the societal level, and conflict within small scale communications between people of opposite opinion. Often, opinion polarization is conceptualized as the direct opposite of agreement and consequently operationalized as an index of dispersion. However, in doing so, researchers fail to account for the bimodality that is characteristic of a polarized opinion distribution. A valid measurement of opinion polarization would enable us to predict when, and on what issues conflict may arise. The current study is aimed at developing and validating a new index of opinion polarization. The weights of this index were derived from utilizing the knowledge of 58 international experts on polarization through an expert survey. The resulting Opinion Polarization Index predicted expert polarization scores in opinion distributions better than common measures of polarization, such as the standard deviation, Van der Eijk’s polarization measure and Esteban and Ray’s polarization index. We reflect on the use of expert ratings for the development of measurements in this case, and more in general.


2021 ◽  
Vol 42 (19) ◽  
pp. 7581-7609
Author(s):  
Erli Pinto dos Santos ◽  
Demetrius David Da Silva ◽  
Cibele Hummel do Amaral

2021 ◽  
Author(s):  
Zhenxing Wang ◽  
Xiaomin Wang ◽  
Shuiqin Li ◽  
Yongcan Wu ◽  
Demei Huang ◽  
...  

Abstract Background: Long-term exposure to high concentrations of PM2.5 may cause immune system dysfunction and damage to the respiratory and cardiovascular systems. PM2.5 may cause CD4 + T helper cells to polarize toward TH1 or TH2 cell types, which may be associated with the onset and progression of many human diseases. Recent studies have shown that omega-3 fatty acids can regulate human immune function and reduce physiological damage caused by air pollution; however, only limited research has examined the therapeutic effects of omega-3 fatty acids on subjects with high exposure to PM2.5 in mass transit systems such as subways.Methods: This study was designed as a prospective, randomized, double-blinded (to participants and researchers), placebo-controlled trial. The research plan is to recruit 120 qualified volunteers in the Chengdu Metro Station. All participants will receive omega-3 fatty acids or placebo for 8 weeks. The primary outcomes will be changes in the TH1/TH2 cell polarization index and changes in serum cytokine concentrations. Secondary outcomes will be changes in early indicators of atherosclerosis, pulmonary function, COOP/WONCA charts, and scores on the Short Form 36 Health Survey for quality of life. Results will be analyzed to evaluate differences in clinical efficacy between the two groups. A six-month follow-up period will be used to assess the long-term value of omega-3 fatty acids for respiratory and cardiovascular disease end-points.Disscussion: We will explore the characteristics of TH1/TH2 cell polarization index in a population with high exposure to PM2.5. Omega-3 fatty acids and placebo will be compared in many ways to test the effect on people exposed to PM2.5 subway stations. This study is expected to provide reliable evidence to support the promotion of omega-3 fatty acids in clinical practice to protect individuals who are highly exposed to PM2.5.Trial registration: Chinese Clinical Trial Registry (ChiCTR2000038065). Registered on September 9, 2020.


Gunahumas ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 43-48
Author(s):  
Elih Mulyana ◽  
Hasbullah Hasbullah ◽  
Dzikri Sayefullah

The transformer is the leading equipment in the electric power system that is directly related to the electrical transmission and distribution system. An essential part of a power transformer is its insulation system. Along with age and its operation, the condition of insulation can be damaged, which can lead to failure of the surgery. The purpose of this study was to determine the quality conditions of the power transformer insulation. The method in this research is observation and study of literature, while the research location is PT PLN (Persero) TJBT APP Cirebon. Data were taken in the form of polarization index and delta tangent test results. After the data is collected, the polarization index and delta tangent are calculated and analyzed. Analysis of the polarization index testing using the primary-ground, secondary-ground, tertiary-ground, primary-secondary, secondary-tertiary, and primary-tertiary methods. Whereas tangent delta testing is the relationship between CH, CHL, CL, CT, CHT, and CLT.The results of tests with delta polarization and tangent indexes that the transformer isolation resistance is still good and the transformer is feasible to operate.


eLEKTRIKA ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 60
Author(s):  
Muhamad Firdaus Robbani ◽  
Dedi Nugroho ◽  
Gunawan Gunawan

<p><em>A power transformer is electrical power equipment that works to transmit power or electrical power from high voltage to low voltage or on the contrary. In the operation of distributing electricity, the transformer can be said to be the heart of transmission and distribution. In this condition, a transformer is expected to operate optimally according to its function.. If the isolation state of the transformer deteriorates, it can have an impact on operating failure and the most fatal of which is that the transformer is damaged which can cause disturbances in the electrical system. To overcome this, it is necessary to analyze the isolation resistance.</em></p><p><em>This study analyzes the isolation resistance on a transformer using the polarization index, tangent delta and oil breakdown voltage methods to determine the quality of the isolation on the transformer. This study took data at the 150 Kv substation Tegal. The data used include polarization index test data, tangent delta data, bottom oil breakdown voltage test data, and OLTC oil. After the data is obtained, then calculations and analyzes are carried out to obtain accurate results.</em></p><p><em>The test results at the 150 Kv substation Tegal showed the polarization index value with the lowest IP of 1.26 in the primary-ground section and the highest IP of 1.97 in the primary-secondary section is still in good condition. The results of the tangent delta test are still in good condition, only in the CHT mode experienced a negative delta tan deterioration of 0.07%. The result of the average oil test is still suitable for use with 69.9 Kv of bottom oil and 53.3 Kv of OLTC oil.</em></p>


2020 ◽  
Vol 21 (2) ◽  
pp. 100
Author(s):  
Akmal Radiansyah ◽  
Albert Gifson

An electric motor that is used continuously will experience a decline in performance and even be damaged, maintenance and repair of electric motors must be done based on standards so that all existing specifications can be met and repairs deserve to be accepted. Where in this case motor repair is done by overhauling, where overhaul is a comprehensive repair or maintenance activity by repairing or replacing parts of electric motors that are damaged. Based on visual data and electrical measurements the decrease in the value of the polarization index (PI) of the induction motor is caused by dirty and moist winding conditions. Overhaul is done in 8 stages, namely; planning, dismantling, electrical measurement, mechanical measurement, electrical action, mechanical action, assembling and no load test running. After overhauling, the result shows that the value of the polarization index (PI) increased by 1.4 from 1.8 to 3.2, which is above the standard value set by IEEE 43.ABSTRAK:Suatu motor listrik yang digunakan terus menerus akan mengalami penurunan performa bahkan rusak, perawatan dan perbaikan motor listrik harus dilakukan berdasarkan standar supaya semua spesifikasi yang ada dapat terpenuhi dan perbaikan layak untuk diterima. Dimana pada kasus ini perbaikan motor diakukan dengan cara overhaul, dimana overhaul merupakan kegiatan perbaikan atau perawatan secara menyeluruh dengan cara memperbaiki atau mengganti bagian dari motor listrik yang mengalami kerusakan. Berdasarkan data visual dan pengukuran elektrik penurunan nilai polarization index (PI) motor induksi disebabkan oleh kondisi winding yang kotor dan lembab. Overhaul dilakukan dengan 8 tahapan, yaitu; planning, dismantling, pengukuran elektrik, pengukuran mekanik, tindakan elektrik, tindakan mekanik, assembling dan running test no load. Setelah overhaul didapatkan hasil bahwa nilai polarization index (PI) meningkat sebesar 1.4 dari sebelumnya 1.8 menjadi 3.2, berada diatas nilai standar yang ditetapkan oleh IEEE 43


2019 ◽  
Vol 10 ◽  
Author(s):  
Gunnar Treff ◽  
Kay Winkert ◽  
Mahdi Sareban ◽  
Jürgen M. Steinacker ◽  
Billy Sperlich

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