Local search algorithms for a single-machine scheduling problem with positive and negative time-lags

Positive and negative time-lags are general timing restrictions between the\ud starting times of jobs which have been introduced in connection with the\ud Metra Potential Method. Although very powerful, these relations have been\ud considered only seldom in the literature since already for a single machine\ud problem with positive and negative time-lags the problem of nding a feasible\ud solution is NP-complete.\ud In this paper a local search approach for a single-machine scheduling problem\ud with positive and negative time-lags and the objective to minimize the\ud makespan is presented. Since the existence of a feasible initial solution for\ud starting the search cannot be guaranteed, infeasible solutions are incorporated\ud into the search process. Computational results based on instances\ud resulting from shop problems are reported

Local search algorithms for a single-machine scheduling problem with positive and negative time-lags

Positive and negative time-lags are general timing restrictions between the starting times of jobs which have been introduced by Roy (C.R. Acad. Sci., 1959, T.248) in connection with the Metra Potential Method. Although very powerful, these relations have been considered only seldom in the literature since already for a single-machine problem with positive and negative time-lags the problem of finding a feasible solution is NP-complete. In this paper a local search approach for a single-machine scheduling problem with positive and negative time-lags and the objective to minimize the makespan is presented. Since the existence of a feasible initial solution for starting the search can not be guaranteed, infeasible solutions are incorporated into the search process. Computational results based on instances resulting from shop problems are reported

A simple evaluation tool (ET-CET) indicates increase of diagnostic skills from Small bowel capsule endoscopy training courses: A prospective observational european multicenter study

Small bowel capsule endoscopy (SBCE) has become a first line diagnostic tool. Several training courses with a similar format have been established in Europe; however, data on learning curve and training in SBCE remain sparse. Between 2008 and 2011, different basic SBCE training courses were organized internationally in UK (n=2), Italy (n= 2), Germany (n=2), Finland (n=1), and nationally in Germany (n=10), applying similar 8-hour curricula with 50% lectures and 50% hands-on training. The Given PillCam System was used in 12 courses, the Olympus EndoCapsule system in 5, respectively. A simple evaluation tool for capsule endoscopy training (ET-CET) was developed using 10 short SBCE videos including relevant lesions and normal or irrelevant findings. For each video, delegates were required to record a diagnosis (achievable total score from 0 to 10) and the clinical relevance (achievable total score 0 to 10). ET-CET was performed at baseline before the course and repeated, with videos in altered order, after the course. Two hundred ninety-four delegates (79.3% physicians, 16.3% nurses, 4.4% others) were included for baseline analysis, 268 completed the final evaluation. Forty percent had no previous experience in SBCE, 33% had performed 10 or less procedures. Median scores for correct diagnosis improved from 4.0 (IQR 3) to 7.0 (IQR 3) during the courses (P<0.001, Wilcoxon), and for correct classification of relevance of the lesions from 5.0 (IQR 3) to 7.0 (IQR 3) (P<0.001), respectively. Improvement was not dependent on experience, profession, SBCE system, or course setting. Previous experience in SBCE was associated with higher baseline scores for correct diagnosis (P< 0.001; Kruskal-Wallis). Additionally, independent nonparametric partial correlation with experience in gastroscopy (rho 0.33) and colonoscopy (rho 0.27) was observed (P<0.001). A simple ET-CET demonstrated significant improvement of diagnostic skills on completion of formal basic SBCE courses with hands-on training, regardless of preexisting experience, profession, and course setting. Baseline scores for correct diagnoses show a plateau after interpretation of 25 SBCE before courses, supporting this number as a compromise for credentialing. Experience in flexible endoscopy may be useful before attending an SBCE course

Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). The Guideline was also reviewed and endorsed by the British Society of Gastroenterology (BSG). It addresses the roles of small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders. Main recommendations 1 ESGE recommends small-bowel video capsule endoscopy as the first-line investigation in patients with obscure gastrointestinal bleeding (strong recommendation, moderate quality evidence). 2 In patients with overt obscure gastrointestinal bleeding, ESGE recommends performing small-bowel capsule endoscopy as soon as possible after the bleeding episode, optimally within 14 days, in order to maximize the diagnostic yield (strong recommendation, moderate quality evidence). 3 ESGE does not recommend the routine performance of second-look endoscopy prior to small-bowel capsule endoscopy; however whether to perform second-look endoscopy before capsule endoscopy in patients with obscure gastrointestinal bleeding or iron-deficiency anaemia should be decided on a case-by-case basis (strong recommendation, low quality evidence). 4 In patients with positive findings at small-bowel capsule endoscopy, ESGE recommends device-assisted enteroscopy to confirm and possibly treat lesions identified by capsule endoscopy (strong recommendation, high quality evidence). 5 ESGE recommends ileocolonoscopy as the first endoscopic examination for investigating patients with suspected Crohn's disease (strong recommendation, high quality evidence). In patients with suspected Crohn's disease and negative ileocolonoscopy findings, ESGE recommends small-bowel capsule endoscopy as the initial diagnostic modality for investigating the small bowel, in the absence of obstructive symptoms or known stenosis (strong recommendation, moderate quality evidence). ESGE does not recommend routine small-bowel imaging or the use of the PillCam patency capsule prior to capsule endoscopy in these patients (strong recommendation, low quality evidence). In the presence of obstructive symptoms or known stenosis, ESGE recommends that dedicated small bowel cross-sectional imaging modalities such as magnetic resonance enterography/enteroclysis or computed tomography enterography/enteroclysis should be used first (strong recommendation, low quality evidence). 6 In patients with established Crohn's disease, based on ileocolonoscopy findings, ESGE recommends dedicated cross-sectional imaging for small-bowel evaluation since this has the potential to assess extent and location of any Crohn's disease lesions, to identify strictures, and to assess for extraluminal disease (strong recommendation, low quality evidence). In patients with unremarkable or nondiagnostic findings from such cross-sectional imaging of the small bowel, ESGE recommends small-bowel capsule endoscopy as a subsequent investigation, if deemed to influence patient management (strong recommendation, low quality evidence). When capsule endoscopy is indicated, ESGE recommends use of the PillCam patency capsule to confirm functional patency of the small bowel (strong recommendation, low quality evidence). 7 ESGE strongly recommends against the use of small-bowel capsule endoscopy for suspected coeliac disease but suggests that capsule endoscopy could be used in patients unwilling or unable to undergo conventional endoscopy (strong recommendation, low quality evidence)

Bindings as bounded natural functors

We present a general framework for specifying and reasoning about syntax with bindings. Abstract binder types are modeled using a universe of functors on sets, subject to a number of operations that can be used to construct complex binding patterns and binding-aware datatypes, including non-well-founded and infinitely branching types, in a modular fashion. Despite not committing to any syntactic format, the framework is “concrete” enough to provide definitions of the fundamental operators on terms (free variables, alpha-equivalence, and capture-avoiding substitution) and reasoning and definition principles. This work is compatible with classical higher-order logic and has been formalized in the proof assistant Isabelle/HOL