An engineering and economic evaluation of some mixed-mode waste heat rejection systems

Originally presented as the first author's thesis, (Sc. D.)--in the M.I.T. Dept. of Nuclear Engineering, 1977Includes bibliographical references (p. 336-342

Investigation of solution techniques for large sparse band width matrix equations of linear systems

Includes bibliographical references (leaves 107-108

Low autocorrelated multi-phase sequences

The interplay between the ground state energy of the generalized Bernasconi model to multi-phase, and the minimal value of the maximal autocorrelation function, $C_{max}=\max_K{|C_K|}$, $K=1,..N-1$, is examined analytically and the main results are: (a) The minimal value of $\min_N{C_{max}}$ is $0.435\sqrt{N}$ significantly smaller than the typical value for random sequences $O(\sqrt{\log{N}}\sqrt{N})$. (b) $\min_N{C_{max}}$ over all sequences of length N is obtained in an energy which is about 30% above the ground-state energy of the generalized Bernasconi model, independent of the number of phases m. (c) The maximal merit factor $F_{max}$ grows linearly with m. (d) For a given N, $\min_N{C_{max}}\sim\sqrt{N/m}$ indicating that for m=N, $\min_N{C_{max}}=1$, i.e. a Barker code exits. The analytical results are confirmed by simulations.Comment: 4 pages, 4 figure

Economic feasibility study of total energy system options for the Massachusetts Institute of Technology

Includes bibliographical references (leaf 39)Prepared for the MIT Physical Plant Dep

The Code White protocol: a mixed somatic-psychiatric protocol for managing psychomotor agitation in the ED

Objectives: Clinical management of patients presenting with acute psycho­motor agitation is difficult, often because there is no predefined protocol for dealing with it. The main objective of this article is to describe our ­institution’s Code White mixed somatic-psychiatric protocol for managing acute agitation in an emergency department. Its second objective is to ­present data on how long it took to initiate and complete treatment. Methods: We retrospectively analysed 250 clinical situations over 3 years (2014–2016) from the hospital emergency department in the canton of Neuchâtel, Switzerland. Results: The median time from emergency department arrival to treatment initiation was 7 minutes; the median duration of treatment was 119 minutes. The rate of hospitalisation after emergency department treatment was 49.2%. Conclusion: This mixed somatic-psychiatric protocol seemed to reduce both the time before treatment initiation and treatment duration for ­patients presenting with acute psychomotor agitation in an emergency ­department. Implications for practice: The Code White protocol improved the emergency department’s ability to keep acutely agitated patients flowing smoothly and efficiently through it to other units or to discharge. On the qualitative level, it also improved staff safety and peace of mind, allowing them to carry out their many tasks more calmly

Predicting involuntary hospitalization in psychiatry: A machine learning investigation.

Coercion in psychiatry is a controversial issue. Identifying its predictors and their interaction using traditional statistical methods is difficult, given the large number of variables involved. The purpose of this study was to use machine-learning (ML) models to identify socio-demographic, clinical and procedural characteristics that predict the use of compulsory admission on a large sample of psychiatric patients. We retrospectively analyzed the routinely collected data of all psychiatric admissions that occurred between 2013 and 2017 in the canton of Vaud, Switzerland (N = 25,584). The main predictors of involuntary hospitalization were identified using two ML algorithms: Classification and Regression Tree (CART) and Random Forests (RFs). Their predictive power was compared with that obtained through traditional logistic regression. Sensitivity analyses were also performed and missing data were imputed through multiple imputation using chain equations. The three models achieved similar predictive balanced accuracy, ranging between 68 and 72%. CART showed the lowest predictive power (68%) but the most parsimonious model, allowing to estimate the probability of being involuntarily admitted with only three checks: aggressive behaviors, who referred the patient to hospital and primary diagnosis. The results of CART and RFs on the imputed data were almost identical to those obtained on the original data, confirming the robustness of our models. Identifying predictors of coercion is essential to efficiently target the development of professional training, preventive strategies and alternative interventions. ML methodologies could offer new effective tools to achieve this goal, providing accurate but simple models that could be used in clinical practice

Endogenous chemical exchange saturation transfer (CEST) MR imaging for the diagnosis and therapy response assessment of brain tumors: A systematic review

Purpose: To generate a narrative synthesis of published data on the use of endogenous chemical exchange saturation transfer (CEST) MR imaging in brain tumors. Materials and Methods: A systematic database search (PubMed, Ovid Embase, Cochrane Library) was used to collate eligible studies. Two researchers independently screened publications according to predefined exclusion and inclusion criteria, followed by comprehensive data extraction. All included studies were subjected to a bias risk assessment using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Results: The electronic database search identified 430 studies, of which 36 studies fulfilled the inclusion criteria. The final selection of included studies was categorized into 5 groups as follows: grading gliomas, 19 studies (areas under the curve (AUC) 0.500-1.000); predicting molecular subtypes of gliomas, 5 studies (AUC 0.610-0.920); distinction of different brain tumor types, 7 studies (AUC 0.707-0.905); therapy response assessment, 3 studies (AUC not given) and differentiating recurrence from treatment-related changes, 5 studies (AUC 0.880- 0.980). A high bias risk was observed in a substantial proportion of studies. Conclusion: Endogenous CEST imaging offers valuable, potentially unique information in brain tumors, but its diagnostic accuracy remains incompletely known. Further research is required to assess the method’s role in support of molecular genetic diagnosis, to investigate its use in the post treatment phase, and to compare techniques with a view to standardization

Replica Field Theory for Deterministic Models (II): A Non-Random Spin Glass with Glassy Behavior

We introduce and study a model which admits a complex landscape without containing quenched disorder. Continuing our previous investigation we introduce a disordered model which allows us to reconstruct all the main features of the original phase diagram, including a low $T$ spin glass phase and a complex dynamical behavior.Comment: 35 pages with uu figures, Roma 102