Buffer optimization and robust design studies in asynchronous assembly systems using design of experiments approach

This research concentrates on the buffer specification problem of the design of asynchronous assembly systems (AAS). The objectives of the research are to determine an optimal area of buffers and to design AAS that are robust to noise factors. In order to determine an optimal area of buffers in which the throughput yields to maximum, the design of experiments (DoE) approach and discrete-event simulation are used, and appropriate buffer levels are identified accordingly. Studies indicated that determining an optimal area provided the design engineer the much needed flexibility to choose the buffer sizes within a range. The DoE approach also offered substantial information on the AAS that can serve the design engineer as an invaluable guideline and enable one to design the AAS with a better understanding. Furthermore, the use of DoE approach as an optimization tool is proposed, principally in cases where little known on the AAS that will be designed. Case studies using the DoE approach as a heuristic optimization method are presented. Additionally, in an attempt to study its effect, in some studies, the number of pallets has been considered as a decision variable. Studies conducted throughout this research indicated that the DoE approach to be an effective methodology. Robust design study is essential to design AAS that are insensitive to uncontrollable factors. Several systems have been investigated and analyses revealed the necessity of robust design study in AAS. Future research areas are suggested

Quality of life and related factors among chronic hepatitis B-infected patients: a multi-center study, Turkey

Background: The aim of this study was to assess health-related quality of life (HRQOL) among chronic hepatitis B (CHB) patients in Turkey and to study related factors

Quality of life and related factors among chronic hepatitis B-infected patients: a multi-center study, Turkey

balkan, ilker inanc/0000-0002-8977-5931; Altindis, Mustafa/0000-0003-0411-9669; Sahin, Ahmet Ziyaettin/0000-0003-1060-6746; atilla, aynur/0000-0001-8027-1991WOS: 000386954300001PubMed: 27809934Background: The aim of this study was to assess health-related quality of life (HRQOL) among chronic hepatitis B (CHB) patients in Turkey and to study related factors. Methods: This multicenter study was carried out between January 01 and April 15, 2015 in Turkey in 57 centers. Adults were enrolled and studied in three groups. Group 1: Inactive HBsAg carriers, Group 2: CHB patients receiving antiviral therapy, Group 3: CHB patients who were neither receiving antiviral therapy nor were inactive HBsAg carriers. Study data was collected by face-to-face interviews using a standardized questionnaire, Short Form-36 (SF-36) and Hepatitis B Quality of Life (HBQOL). Values equivalent to p < 0.05 in analyses were accepted as statistically significant. Results: Four thousand two hundred fifty-seven patients with CHB were included in the study. Two thousand five hundred fifty-nine (60.1 %) of the patients were males. Groups 1, 2 and 3, consisted of 1529 (35.9 %), 1721 (40.4 %) and 1007 (23.7 %) patients, respectively. The highest value of HRQOL was found in inactive HBsAg carriers. We found that total HBQOL score increased when antiviral treatment was used. However, HRQOL of CHB patients varied according to their socio-demographic properties. Regarding total HBQOL score, a higher significant level of HRQOL was determined in inactive HBV patients when matched controls with the associated factors were provided. Conclusions: The HRQOL score of CHB patients was higher than expected and it can be worsen when the disease becomes active. Use of an antiviral therapy can contribute to increasing HRQOL of patients