An MIP Approach to the U-line Balancing Problem With Proportional Worker Throughput

One of the major challenges faced by manufacturing companies is to remain competitive in dynamic environments, where fluctuations in customer demand and production rates require systems capable of adapting in a practical and economical way. A U-shaped production cell is considered one of the most flexible designs for adapting the workforce level to varying conditions. However, re-balancing efforts are time consuming and often require a new work allocation and line design. In this paper, a two-stage MIP model to determine the best cell design under varying workforce levels is proposed. The model seeks to maintain proportionality between throughput and the number of workers. Computational experiments considering various line configurations (up to 19 stations) and workloads (up to 79 tasks) are performed. The results show the proposed algorithm provides excellent results for all small and medium size problems addressed in this study, as well as for certain configurations of large problems. This approach can be used to generate lookup tables of line designs to help with quick reallocation of worker assignments on the shop floor and with minimal disruption

Evaluating Threat Assessment for Multi-Stage Cyber Attacks

Current practices to defend against cyber attacks are typically reactive yet passive. Recent research work has been proposed to proactively predict hacker\u27s target entities in the early stage of the attack. With prediction, there comes false alarms and missed attacks. Very little has been reported on how to evaluate a threat assessment algorithm, especially for cyber security. Because of the variety and the constantly changing nature of hacker behavior and network vulnerabilities, a cyber threat assessment algorithm is, perhaps more susceptible that for other application domains. This work sets forth the issues on evaluating cyber threat assessment algorithms, and discusses the validity of various statistical measures. Simulation examples are provided to illustrate the pros and cons of using different metrics under various cyber attack scenarios. Our results show that commonly used false positives and false negatives are necessary but not sufficient to evaluate cyber threat assessment

The Population-Centered Medical Model: A Theory of Practice for Public Health and Preventive Medicine

Introduction Public health physicians occupy a unique place in the fields of both medicine and public health. Trained in each field, and often holding positions of authority in public health systems, public health physicians are sometimes challenged to identify their roles in either field of practice. Public health physicians work to achieve population health, but there has been limited theoretical development in this field of practice. Objectives The objective of this research was to develop an empirical theory of practice for public health physicians. Methods A literature review of current practice models applicable to public health physicians was performed. A discourse analysis of Chief Medical Officer of Health (CMOH) media briefings during the COVID-19 pandemic was conducted to understand the socially constructed public-facing identities of public health physicians. A Grounded Theory study of practice was conducted by interviewing public health physician participants. Findings Current practice models for medicine do not account for the work of public health physicians, whose ‘patients’ are populations. Practice models for public health do not account for the unique roles and responsibilities of physicians in public health. The literature review affirmed that there are no published models of practice that are specific to public health physician practice. From the discourse analysis, it was found that Chief Medical Officers of Health (CMOHs) construct a social identity that is recognizably medical by virtue of its technical and relational aspects. The implication of this social identity is that CMOHs view themselves as physicians, and further that they also view populations as patients. The findings of the grounded theory study led to the development of a theory of practice for public health physicians, the Population-Centered Medical Model (POP-CMM). In this model, public health physicians bring values, knowledge, and stances into the practice of public health medicine. Public health physicians view populations as their patients, and the method of practice involves diagnosis and intervention that is focused on systems and prevention. This process of practice relies on knowledge sharing and relationship building between public health physicians and populations. Conclusion The POP-CMM forms a theoretical grounding for the training and practice of public health medicine in Canada. Taken with the findings of the discourse analysis, this inquiry reveals that the practice of public health medicine (and perhaps medicine in general) is constituted by a set of core processes that are enacted across a range of discursive settings. These findings have implications for conceptualizing competence in medical training and practice, as well as for progress toward a general model of medical practice across a spectrum of patients from n=1 to n=N. Further research could demonstrate its transferability to the practice of public health physicians in other countries, to the practice of other professionals in public health, and to the practice of medicine in general. Keywords (alphabetical order) Discourse Analysis, Grounded Theory, Medical Practice, Medicine, Model, Physicians, Population Health, Public Health, Public Health Practice, Theor

Case 10 : Babies and Budgets: Balancing Costs and Consequences in Postpartum Screening

Dr. Philip Singe, the Medical Officer of Health at the King Public Health Unit, is in a meeting with Praveen Gill, manager of the Healthy Babies, Healthy Children (HBHC) program, and Vanessa Thomas, the director of the Family Health portfolio. The group is discussing options for delivering postpartum screening services under the provincially funded HBHC program. While program costs have increased steadily, funding from the provincial Ministry responsible for oversight of HBHC has been stagnant. The group must decide whether or not to cut costs by reducing the number of staff responsible for screening. Faced with the challenge of maintaining the effectiveness of screening services, the group weighs each option. Using expert opinion and historical information, the team must forecast costs and consequences to compare options systematically. The case includes worksheets for budgeting and cost-consequence analysis. Instructors can obtain a copy of the answer key from the MPH Program Office

TANDI: Threat Assessment of Network Data and Information

Current practice for combating cyber attacks typically use Intrusion Detection Sensors (IDSs) to passively detect and block multi-stage attacks. This work leverages Level-2 fusion that correlates IDS alerts belonging to the same attacker, and proposes a threat assessment algorithm to predict potential future attacker actions. The algorithm, TANDI, reduces the problem complexity by separating the models of the attacker\u27s capability and opportunity, and fuse the two to determine the attacker\u27s intent. Unlike traditional Bayesian-based approaches, which require assigning a large number of edge probabilities, the proposed Level-3 fusion procedure uses only 4 parameters. TANDI has been implemented and tested with randomly created attack sequences. The results demonstrate that TANDI predicts future attack actions accurately as long as the attack is not part of a coordinated attack and contains no insider threats. In the presence of abnormal attack events, TANDI will alarm the network analyst for further analysis. The attempt to evaluate a threat assessment algorithm via simulation is the first in the literature, and shall open up a new avenue in the area of high level fusion

PKD1 Inhibits AMPK2 through Phosphorylation of Serine 491 and Impairs Insulin Signaling in Skeletal Muscle Cells

Background: Diminished activity of the enzyme AMP-activated protein kinase (AMPK) is associated with impaired insulin signaling. Results: Protein Kinase (PK)C/D1 activation inhibits AMPK2 via Ser491 phosphorylation; PKD1 inhibition prevents this in skeletal muscle cells. Conclusion: PKD1 is a novel upstream AMPK-kinase that phosphorylates AMPK on Ser491 and regulates insulin signaling. Significance: PKD1 inhibition may be a novel strategy for improving insulin sensitivity

Defective mitochondrial peroxiredoxin-3 results in sensitivity to oxidative stress in Fanconi anemia

Cells from patients with Fanconi anemia (FA), an inherited disorder that includes bone marrow failure and cancer predisposition, have increased sensitivity to oxidative stress through an unknown mechanism. We demonstrate that the FA group G (FANCG) protein is found in mitochondria. Wild-type but not G546R mutant FANCG physically interacts with the mitochondrial peroxidase peroxiredoxin-3 (PRDX3). PRDX3 is deregulated in FA cells, including cleavage by a calpainlike cysteine protease and mislocalization. FA-G cells demonstrate distorted mitochondrial structures, and mitochondrial extracts have a sevenfold decrease in thioredoxin-dependent peroxidase activity. Transient overexpression of PRDX3 suppresses the sensitivity of FA-G cells to H2O2, and decreased PRDX3 expression increases sensitivity to mitomycin C. Cells from the FA-A and -C subtypes also have PRDX3 cleavage and decreased peroxidase activity. This study demonstrates a role for the FA proteins in mitochondria witsh sensitivity to oxidative stress resulting from diminished peroxidase activity. These defects may lead to apoptosis and the accumulation of oxidative DNA damage in bone marrow precursors