Multi-Mode Resource-Constrained Project-Scheduling Problem With Renewable Resources: New Solution Approaches

We consider the multi-mode resource-constrained project scheduling problem (MRCPSP) with renewable resources.  In MRCPSP, an activity can be executed in one of many possible modes; each mode having different resource requirements and accordingly different activity durations.  We assume that all resources are renewable from period to period, such as labor and machines.  A solution to this problem basically involves two decisions – (i) The start time for each activity and (ii) the mode for each activity.  Given the NP-Hard nature of the problem, heuristics and metaheuristics are used to solve larger instances of this problem.  A heuristic for this type of problem involves a combination of two priority rules - one for each of the two decisions.  Heuristics generally tend to be greedy in nature.  In this study we propose two non-greedy heuristics for mode selection which perform better than greedy heuristics.  In addition, we study the effect of double justification and backward/forward scheduling for the MRCPS.  We also study the effect of serial vs. parallel scheduling.  We found that all these elements improved the solution quality.  Finally we propose an adaptive metaheuristic procedure based on neural networks which further improves the solution quality.  The effectiveness of these proposed approaches, compared to existing approaches in the literature, is demonstrated through empirical testing on two well-known sets of benchmark problems

Oral Exam System at Teacher Appointments in Turkey

Oral Exam system is applied all over the world, is recently applied in Turkey. After teacher candidates pass the PESE (General Knowledge, General Skills, Educational Sciences, and TPFK), they receive Oral Exam, and they are appointed with the points they receive from this stage or they are considered as unsuccessful. In other words, while Oral Exams are used as the complementary elements of written and similar other exams in the world, they are used as the sole determinants of appointing teachers in Turkey, which is beyond being complementary. As a matter of fact, in countries where Oral Exams are applied, it is observed that this system is used sometimes for preferential purposes, and the influence of Oral Exams on appointment point is kept low. Another reason for the criticisms of the educational syndicates that are active in Turkey on Oral Exam application is the suspicion of its activating the “preferential treatment” mechanism, because evaluations have subjectivity in them; and the evaluations of the members of the commission about the answers of the candidates are not based on adequate and concrete dat

The Task Scheduling Problem: A NeuroGenetic Approach

This paper addresses the task scheduling problem which involves minimizing the makespan in scheduling n tasks on m machines (resources) where the tasks follow a precedence relation and preemption is not allowed.  The machines (resources) are all identical and a task needs only one machine for processing.  Like most scheduling problems, this one is NP-hard in nature, making it difficult to find exact solutions for larger problems in reasonable computational time.  Heuristic and metaheuristic approaches are therefore needed to solve this type of problem.   This paper proposes a metaheuristic approach - called NeuroGenetic - which is a combination of an augmented neural network and a genetic algorithm.  The augmented neural network approach is itself a hybrid of a heuristic approach and a neural network approach.  The NeuroGenetic approach is tested against some popular test problems from the literature, and the results indicate that the NeuroGenetic approach performs significantly better than either the augmented neural network or the genetic algorithms alone.

Resource Constrained Project Scheduling: A Hybrid Neural Approach

The resource-constrained project scheduling problem (RCPSP) is a well-known NP-Hard problem in scheduling. A variety of metaheuristic approaches have emerged lately for solving this class of problems. This study proposes, develops and tests a hybrid metaheuristic approach based on the principles of neural networks. We use the adaptive-learning approach (ALA) for serial schedule generation and the augmented neural network (AugNN) approach for parallel schedule generation. Both these approaches, i.e., ALA and AugNN, are based on the principles of neural networks and are very different from Hopfield networks. In the ALA approach, weighted processing times are used instead of original processing times. A perturbation strategy allows a non-deterministic local search. In the AugNN approach, traditional neural networks are augmented to allow embedding of domain and problem-specific knowledge. The network architecture is problem specific and a set of complex neural functions are used to (i) capture the constraints of the problem and (ii) apply a priority rule-based heuristic. Such an approach combines the advantages of priority rule-based heuristics and the iterative learning of neural networks. We further show how forward-backward improvement can be integrated into our hybrid neural approach (HNA) framework to improve results. We empirically test our approach on benchmark problems of size J30, J60 and J120 from PSPLIB. Our results are extremely competitive with existing techniques such as genetic algorithms, simulated annealing, tabu search and ant colonies

Cancer stem cells--important players in tumor therapy resistance

Resistance to tumor therapy is an unsolved problem in cancer treatment. A plethora of studies have attempted to explain this phenomenon and many mechanisms of resistance have been suggested over recent decades. The concept of cancer stem cells (CSCs), which describes tumors as hierarchically organized, has added a new level of complexity to therapy failure. CSCs are the root of cancers and resist chemo- and radiotherapy, explaining cancer recurrence even many years after therapy is ended. This review discusses briefly CSCs in cancers, gives an overview of the role of CSCs in therapy resistance, and discusses the potential means of targeting these therapy-resistant tumor cell

Distance and Location of Both Mobile Phones and Health Care Units: Determines the Interference Level

Abstract 60 Million mobile phone holders in the country forces clinics and cellular phones have been started to be in concern as an electromagnetic interference (EMI) source in hospitals. Hospital buildings are very huge buildings that they are not allowing deep radio penetration through the hole those results in higher uplink power transmission (2W of maximum). These two reasons were our motivation to make an investigation to examine the EMI issues surrounding medical equipment, due to interference from communication devices, including GSM900, GSM1800, and 3G digital mobile phones. Electromagnetic interference, particularly of the ECG and ted EEG device was observed, and exposure begins within the range of 1.25m. It has been observed that uplink power is not a reason of interference itself, but the locations of mobiles and health care units are also the reason of interference

Optimization of Shielding Effectiveness of Coaxial Double Braided Screens in Contact

In this paper, the optimization of the shielding effectiveness of double braided coaxial screens in contact is obtained using semi-empirical single braid optimization formulas. Also the effect of the mutual inductance term between the double braided screens in contact is investigated. A sample optimization has been obtained practically, on one of the standard double braided RF coaxial cable namely, RG-142

Are neutrophil-lymphocyte and platelet-lymphocyte ratios valuable in predicting prostate cancer?

Introduction and Hypothesis: We retrospectively evaluated the prognostic impact of neutrophil-lymphocyte ratio (NLR) as a marker for inflammatory and immune state in men with prostate cancer. Materials and Methods: This retrospective study was conducted in a single urology clinic to review the medical data of 558 patients who underwent transrectal prostate needle biopsies between 2007 and 2014. Prior to transrectal prostate needle biopsies, patient histories, physical examinations, and routine laboratory tests including blood biochemistry, urinaly- sis and urine cultures, free PSA and total PSA, rectal examination, transrectal ultrasound findings, and pathology results were evaluated. Results: Benign biopsy results were found in 287 patients (Group 1) using neutrophil / lymphocyte (NLR) and platelet / lymphocyte ratio (PLR). When calculating malignancy in 271 patients (Group 2), there was no significantly difference in NLR and PLR values between benign and malign prostate diseases (p=0.14 and p=0.369, respectively). Conclusion: With reference to the survey prior to the biopsy, NLR and PLR ratio values do not appear to be helpful in the differentiation of benign prostatic hyperplasia and prostate cancer. [Arch Clin Exp Surg 2016; 5(4.000): 194-199