115 research outputs found

    TYPE-I ASSEMBLY LINE BALANCING WITH WORKLOAD SMOOTHING

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    Balancing the assembly lines plays an important role in increasing the productivity of the manufacturing systems. Depending on the objectives, there are various types of this problem. In this study, a Type-1 assembly line balancing problem is considered. It is known that the distribution of workload and equal distribution of idle time in station balancing is important for worker motivation and ergonomics. Once the number of stations is minimized, which is the primary objective in solving a Type-1 problem, the optimum solution found should be analyzed in terms of the smoothness index. Otherwise, the idle time can be distributed unevenly to the stations. Hence, one of the classical problems in assembly line balancing literature, Sawyer problem, is considered in this study. Firstly, the problem is solved via integer programming with Gurobi in Python. In the second stage, the line was smoothed via two techniques including the classical one and the proposed min-max approach. Different cycle times are tested and a comparison is provided for the two techniques

    Serological diagnosis of syphilis: Preliminary study searching for an algorithm in Turkey

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    Different algorithms have been proposed to increase the diagnostic capacity of syphilis. We analyzed three common algorithms for detecting suspected syphilis cases in low prevelance Turkish population. The study included a total of 340 clinical serum samples from adults throughout Turkey, who had syphilis as a clinical preliminary diagnosis and  were positive on at least one of the following tests: Rapid Plasma Reagin (RPR), Treponema pallidum Haemagglutination test (TPHA) and FTA-abs Ig. In adittion to percent agreement, kappa coefficients were calculated to compare the conformity between the three algorithms. Both the reverse and the ECDC algorithms had higher diagnostic efficacy than the conventional algorithm. The sensitivity/specificity/ accuracy of conventional, reverse and ECDC algorithms were 51.3%/86.1%/55%; 80.9%/86.1%/81.4% and 80.9%/100%/82.9% respectively. The interrater reliability was moderate for conventional-reverse algorithm (73.53%; к=0.484; 95%CI=0.41-0.56; p=0.001) and conventional-ECDC algorithm (72.06%; к=0.454; 95% CI= 0.37-0.54; p=0.001), and near perfect for reverse-ECDC algorithm (98.53%; к=0.963; 95% CI=0.93-0.99; p=0.0001). Our data support the use of ECDC algorithm in serological diagnosis of syphilis. It may increase the diagnostic capacity if treponemal tests are used for screening, and then positive results are confirmed with a different and second treponemal test. e idea that non-Dsg antigens may also be the target for pemphigus autoimmunity.  </p

    Is ecological footprint related to foreign trade? Evidence from the top ten fastest developing countries in the global economy

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    An ecological footprint (EF) refers to the resources that are used by the people or production companies in an area for commerce, which includes the production of food, water resources, and housing; however, it also in-cludes foreign trade of the products produced. The present study aims to examine how foreign trade affects EF and recommend specific new policies or revisions to policies to reduce EF. EF is used as an environmental in-dicator in the present study. The top 10 fastest developing countries (Argentina, Brazil, China, India, Indonesia, Mexico, Poland, South Africa, South Korea, and Turkey) comprised the study sample. The analyses were con-ducted using annual data for the period of 1990-2018; export and import data were taken as foreign trade variables, and their relationship with EF was tested through two different models. Renewable energy con-sumption (REC) and national income were modeled as control variables, and second-generation panel data analysis techniques were used. When the Durbin-Hausman cointegration test was applied, the data indicated a strong correlation between foreign trade and EF. According to the Common Correlated Effects (CCE) coefficient estimator, there was an inverse relationship between exports and REC and EF and a positive relationship with economic growth. When the Augmented Mean Group (AMG) coefficient estimator was applied, an inverse cor-relation was indicated among exports, imports, REC, and EF. Based on the findings of the analyses, it can be argued that policymakers and market players should manage foreign trade and environmental policies in a harmonized manner, and long-term planning should be shaped around these test results

    An integrated model for cost-oriented assembly line balancing and parts feeding with supermarkets

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    This paper aims to deal with assembly line design from both line balancing and parts feeding (PF) aspects as two-interrelated decision problems while supermarkets are used. These problems arise in the real-world assembly lines (ALs) where decision makers are planning to simultaneously determine the optimal number of stations and the optimal number of supermarkets so that the total installation costs of ALs including line balancing and PF costs are minimized. To this purpose an integrated mathematical model is proposed and its performance is tested through solving a number of benchmark problems and a real case taken from industry.CC BY-NC-ND 4.0</p

    A mathematical model for supermarket location problem with stochastic station demands

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    This paper aims to investigate the effect of station demands variations on supermarket location problem (SLP). This problem arises in the real-world assembly line part feeding (PF) context where supermarkets are used as the intermediate storage areas for stations. To this purpose a stochastic SLP model is developed to optimize the total cost of PF in terms of shipment, inventory and installation costs. The computational results over a real case as well as different test instances verify that the station demands variation has an effect on the SLP solutions.CC BY-NC-ND 4.0</p

    Intellectual Capital in Enterprises and a Model Study in an Industrial Zone

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    Intellectual Capital in Enterprises and a Model Study in an Industrial Zone AbstractThe study mainly consists of two parts. The first part includes theoretical knowledge, the second part includes application-oriented information.In the theoretical part of the study, intellectual capital and SMEs are emphasized in general. In the application-oriented part of the study, a field research will be done for Corum SME. In this study, the demographic structure of Corum SMEs, intellectual capital structure and financial performance of this structure will be evaluated. The resulting data will be analyzed in this context. The businesses operating in the Organized Industrial Zone of Corum and those matching the definition of SME will be considered within the research scope. Surveys will be applied by interviewers face to face and each survey will be evaluated individually. After the evaluation, a model will be proposed.The aim of our study is to investigate the relationship between components of intellectual capital in SMEs and business performance. For this reason, a survey will be conducted for SMEs. Since the results of the study will be shared with scientific circles and the public, they will prove to be guiding for Çorum SMEs.

    Evaluation of symptomatic patients with resistant discharge

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    The aim of this study was to detect the presence of Chlamydia trachomatis, Neisseria (N.) gonorrhoeae, Mycoplasma (M.) hominis, M. genitalium, Ureaplasma (U.) urealyticum, and Trichomonas (T.) vaginalis in patients with resistant discharge. The study also evaluated the concordance of the diagnostic tests. Samples from 156 patients were tested by direct microscopy and culture for T. vaginalis and Mycoplasma IES for M. hominis and U. urealyticum. Multiplex Polymerase Chain Reaction (PCR) was used to determine the presence of six agents. Statistical analyses were performed using the SPSS program. Out of 156 patients, 38 had positive result for the agents tested. Of these 38 patients, 28 (73.7%) had single agent positivity and 10 (26.3%) had multiple agent positivity. The detection rate of U. urealyticum, M. hominis, N. gonorrhoeae, C. trachomatis, T. vaginalis, M. genitalium specifically was 10.3%, 9.6%, 6.4%, 3.2%, 2.6%, 0.6% respectively. N. gonorrhoeae and U. urealyticum were the most common in male patients, while M. hominis and U. urealyticum were mostly found in female patients. Different methods used for detecting T. vaginalis were compared to find that interrater reliability was perfect for culture-direct microscopy (κ:0.85; P&lt;0.001) and also for culture-PCR (κ:0.89; P&lt;0.001). The interrater reliability was moderate (κ:0.53; P&lt;0.001) for PCR-Mycoplasma IES test for M. hominis and fair (κ:0.21; P&lt;0.007) for U. urealyticum. U. urealyticum and M. hominis were among the most commonly found sexually transmitted infections (STI) agents in patients with resistant discharge. Multiple agent positivity was high and should be kept in mind in every STI case. </p
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