Multi-objective optimization in single-row layout design using a genetic algorithm

This paper presents the development of a genetic algorithm for determining a common linear machine sequence for multi-products with different operation sequences and facilities with a limited number of duplicate machine types available for a job. This work aims to minimize the total flow distance travelled by products, reduce the number of machines arranged in the final linear sequence, and decrease the total investment cost of the machines used in the final sequence. We assume that product flow runs only in the forward direction, either via in-sequence or bypass movement. We demonstrate the effectiveness of the proposed algorithm by solving a typical layout design problem taken from literature, and several randomly generated problems. Results indicate that the proposed algorithm serves as a practical decision support tool for resolving layout problems in manufacturing facilities

Estimating the Environmental Cost of Shrimp Farming in Coastal Areas of Chittagong and Coxs bazaar in Bangladesh

During the last three decades, shrimp has remained one of the major export items in Bangladesh. It contributes to the development of this country by enhancing export earnings and promoting employment. However, coastal wetlands and agricultural lands are used for shrimp culture, which reduces agricultural opportunity and peasants income, and destroys the mangroves and coastal eco-system. These are the external environmental costs that are not reflected in farmers price and output decisions. This study has aimed to estimate those external environmental costs through the contingent valuation method. The calculated environmental cost of shrimp farming is USD 13.66 per acre per year. Findings suggest that current shrimp production and shrimp price will no longer be optimal once the external costs are internalized. Thus alternative policy recommendations have been proposed so that shrimp farming becomes a sustainable and equitable means of aquaculture.Comment: 28 page

Characterization of transformer FRA signature under various winding faults

Frequency response analysis (FRA) is gaining global popularity in detecting power transformer winding and core deformations due to the development of FRA test equipment. However, because FRA relies on graphical analysis, interpretation of its signatures is still a very specialized area that calls for skillful personnel to detect the sort and likely place of the fault as so far, there is no reliable standard code for FRA signature classification and quantification. This paper aims to initiate the establishment of standard codes for FRA signature interpretation through comprehensive simulation analysis on a detailed transformer distributed parameters-based model. Various mechanical faults such as axial displacement, buckling stress, disk space variation and bushing fault are simulated on the model to study its impact on the FRA signature. The main contribution of this paper is the comprehensive table it presents for FRA signature sensitivity to winding and core deformations that can be used for classification and quantification of the transformer FRA signature

A simple heuristic for linear sequencing of machines in layout design

This paper presents a simple heuristic to determine a common linear machine sequence for multiple products with different operation sequences and a limited number of duplicate machine types available for the job. The heuristic is based on minimisation of the total flow distance travelled by a product on the linear machine sequence. It is assumed that the flows of products are allowed only in the forward direction, either in-sequence or by-pass. It is also assumed that backtrack movements are not allowed. The effectiveness of the proposed heuristic is demonstrated through the solutions of two typical layout design problems taken from the literature. Subsequently, a number of additional problems are solved and their results are compared with the results applying existing methods. The results indicate that the proposed method can be an effective tool in solving layout design problems

Blood pressure and its associated factors: a comparative study among rural and urban adolescents in Bangladesh

Background: Hypertension in adolescents may lead to irreversible damages in vital organs, such as heart, brain, kidney and may cause death if treatments are not given despite early diagnosis. The aim of this study is to identify the status of blood pressure and its associated factors among adolescents.Methods: It was a cross-sectional study. 810 adolescents of 8 schools and colleges in Chittagong district were collected by stratified cluster sampling technique. Ages of the respondents were 14 to 19. Status of Blood pressure and its associated factors in urban and rural area were the main outcome of interest.Results: The study found the significant difference in physical activities and overweight statistics between urban and rural adolescents (P<0.001). Obesity was found only in the urban area that was 1.2%. The mean systolic blood pressure (114.53 mmHg, 110.61 mmHg) and mean diastolic blood pressure (69.87 mmHg, 68.58 mmHg) of boys and girls in urban respondents were more than rural (109.79 mmHg, 68.97 mmHg and 105.02 mmHg, 67.941 mmHg respectively) and was statistically significant (P<0.001). The mean SBP and DBP were 126 mmHg and 79 mmHg respectively among obese. In the study prevalence of hypertension was 1.5% in urban adolescents and 0.2% in rural adolescents. Consumption of fast food, living area, physical activity, paternal hypertension and BMI were found significantly associated (p<0.05) with hypertension among urban adolescents.Conclusions: The results suggest that hypertension and pre-hypertension is an important public health problem among adolescents in urban than rural. The main associated factors are fast food consumption, living area, physical activity, paternal hypertension and BMI

Mandated Social Disclosure : An Analysis of the Response to the California Transparency in Supply Chains Act of 2010

Peer reviewedPostprin

Verifikasi Desain Antena Berbasis Dipol Berbentuk V untuk Pengamatan Garis 21 Cm

21 cm adalah salah satu garis emisi penting didalam astronomi radio. Garis ini umumnya digunakan untuk mempelajari karakteristik galaksi-galaksi. Artikel ini mempresentasikan sebuah antena dipol berbentuk V untuk sistem telekop radio 21 cm, yang berkorespondensi dengan frekuensi pengamatan 1420MHz. Designnya telah diimplementasikan dan diukur. Hasil pengukuran memperlihatkan kesesuaian dengan simulasi, dengan eror frekuensi puncak sebesar 0,7%. SWR yang diperoleh juga cukup rendah, yaitu sekitar 1,14. Antena yang diajukan pada artikel ini berpotensi untuk digunakan sebagai feed pada antena reflektor atau sebagai elemen penyusun pada sebuah sistem antena array