A Gemoetrical Approach to Computing Expected Cycle Times for Class-Based Storage Layouts in AS/RS

An exact, geometry-based analytical model is presented that can be used to compute the expected cycle time for a storage/retrieval (S/R) machine, executing single-commands, dual-commands, or both, in a rack structure that has been laid out in pre-specified storage zones for classes of goods.The rack may be either square-in-time or non-square-in-time.The approach is intuitively appealing, and it does not assume any certain layout shape, such as traditional "L-shaped" class layouts.The model has been coded in Turbo Pascal, and can be used by designers as a tool for quickly evaluating alternative layout configurations with respect to expected S/R cycle time in an AS/RS, and thereby the throughput of an automated warehouse over time.This model has been successfully applied in a major manufacturing plant in Europe to evaluate reconfigurations of their rack storage layouts over the past five years.Automated storage and retrieval systems;AS/RS;class-based storage.

A Gemoetrical Approach to Computing Expected Cycle Times for Class-Based Storage Layouts in AS/RS

An exact, geometry-based analytical model is presented that can be used to compute the expected cycle time for a storage/retrieval (S/R) machine, executing single-commands, dual-commands, or both, in a rack structure that has been laid out in pre-specified storage zones for classes of goods.The rack may be either square-in-time or non-square-in-time.The approach is intuitively appealing, and it does not assume any certain layout shape, such as traditional "L-shaped" class layouts.The model has been coded in Turbo Pascal, and can be used by designers as a tool for quickly evaluating alternative layout configurations with respect to expected S/R cycle time in an AS/RS, and thereby the throughput of an automated warehouse over time.This model has been successfully applied in a major manufacturing plant in Europe to evaluate reconfigurations of their rack storage layouts over the past five years.

Automatic, fast and robust characterization of noise distributions for diffusion MRI

Knowledge of the noise distribution in magnitude diffusion MRI images is the centerpiece to quantify uncertainties arising from the acquisition process. The use of parallel imaging methods, the number of receiver coils and imaging filters applied by the scanner, amongst other factors, dictate the resulting signal distribution. Accurate estimation beyond textbook Rician or noncentral chi distributions often requires information about the acquisition process (e.g. coils sensitivity maps or reconstruction coefficients), which is not usually available. We introduce a new method where a change of variable naturally gives rise to a particular form of the gamma distribution for background signals. The first moments and maximum likelihood estimators of this gamma distribution explicitly depend on the number of coils, making it possible to estimate all unknown parameters using only the magnitude data. A rejection step is used to make the method automatic and robust to artifacts. Experiments on synthetic datasets show that the proposed method can reliably estimate both the degrees of freedom and the standard deviation. The worst case errors range from below 2% (spatially uniform noise) to approximately 10% (spatially variable noise). Repeated acquisitions of in vivo datasets show that the estimated parameters are stable and have lower variances than compared methods.Comment: v2: added publisher DOI statement, fixed text typo in appendix A

Effect of sport-tinted contact lenses for contrast enhancement on retinal straylight measurements

PURPOSE: To investigate the effect of two tinted contact lenses (CL) designed for outdoor sports activity on the psychometric determination of retinal straylight using the compensation comparison method. METHODS: Thirteen emmetropic subjects were randomly fitted with two different tinted Nike Maxsight (Bausch & Lomb, Rochester, NY, USA) CL in one eye, while the contralateral eye was fitted with a clear lens made of the same material (Optima 38, Bausch & Lomb). Three valid straylight measurements were taken on each eye before and a few minutes after lens insertion, when lens stabilization had occurred. RESULTS: The subjects' mean straylight values were 0.90 +/- 0.09 at baseline and 0.95 +/- 0.10 with the clear Optima 38 CL. Straylight values were 0.97 +/- 0.10 and 1.0 +/- 0.10 log units with the amber and grey-green tinted CL, respectively. Differences in straylight between baseline (without CL) and with the clear CL in place were neither statistically significant (p = 0.066) nor was there a significant difference between baseline and the amber CL (p = 0.052). However, the grey-green CL showed a statistically significant difference from baseline (p = 0.006). Differences in straylight with the clear CL compared with the grey-green CL were also statistically different from zero (p = 0.002) showing an increased straylight value for the tinted CL. These differences were variable, but consistent for each subject, thus those showing higher or lower changes with one tinted lens tended to show the same trend with the second lens (r(2) = 0.736). CONCLUSIONS: Despite increases having been found in straylight values with tinted contact lenses, those changes are not likely to induce clinically significant changes in visual function under photopic conditions, even for the grey-green CL, which seems to increase straylight values more significantly than the amber CL. This difference between the tinted CL could suggest a wavelength dependence of straylight values, although this should be investigated further by controlling for pupil size and subjects' pigmentation, as well as by using neutral density filters

Phenomenology and therapeutic potential of patient experiences during oral esketamine treatment for treatment-resistant depression:an interpretative phenomenological study

Background: Ketamine and its enantiomers are widely researched and increasingly used to treat mental disorders, especially treatment-resistant depression. The phenomenology of ketamine-induced experiences and their relation to its psychotherapeutic potential have not yet been systematically investigated.Aims: To describe the phenomenology of patient experiences during oral esketamine treatment for treatment-resistant depression (TRD) and to explore the potential therapeutic relevance of these experiences.Methods: In-depth interviews were conducted with 17 patients after a 6-week, twice-weekly ‘off label’ generic oral esketamine (0.5–3.0mg/kg) treatment program. Interviews explored participants’ perspectives, expectations, and experiences with oral esketamine treatment. Audio interviews were transcribed and analyzed using an Interpretative Phenomenological Analysis (IPA) framework.Results: The effects of ketamine were highly variable, and psychological distress was common in most patients. Key themes included (a) perceptual effects (auditory, visual, proprioceptive), (b) detachment (from body, self, emotions, and the world), (c) stillness and openness, (d) mystical-type effects (transcendence, relativeness, spirituality), and (e) fear and anxiety. Key themes related to post-session reports included (a) feeling hungover and fatigued, and (b) lifting the blanket: neutralizing mood effects.Conclusion: Patients reported several esketamine effects with psychotherapeutic potential, such as increased openness, detachment, an interruption of negativity, and mystical-type experiences. These experiences deserve to be explored further to enhance treatment outcomes in patients with TRD. Given the frequency and severity of the perceived distress, we identify a need for additional support in all stages of esketamine treatment.</p

Psychedelics for the treatment of depression, anxiety, and existential distress in patients with a terminal illness:a systematic review

Background Terminally ill patients may experience existential distress, depression, or anxiety, limiting quality of life in the final stage. Existing psychotherapeutic or pharmacological interventions have (time) limited efficacy. Psychedelic treatment may be a safe and effective alternative treatment option. Aim Systematically review studies on psychedelic treatment with and without psychotherapy for existential distress, depression, and anxiety in terminally ill patients. Methods Medline, PsycINFO, and Embase were searched for original-data studies on the treatment of depression, anxiety, and existential distress with classical or a-typical psychedelics in patients with a terminal illness, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results A total of 1850 records were screened, and 33 articles were included in this review: 14 studies on classical psychedelics (DPT, LSD, and psilocybin) and 19 studies on atypical psychedelics (MDMA and ketamine). Results of early pre-post studies are promising but have serious methodological flaws. Recent (controlled) trials with LSD, psilocybin, ketamine, and MDMA are of higher methodological quality and indicate positive effects on existential and spiritual well-being, quality of life, acceptance, and reduction of anxiety and depression with few adverse and no serious adverse effects. Conclusions Both classical and a-typical psychedelics are promising treatment options in patients with terminal illness. To draw final conclusions on effectiveness and safety of psychedelics, we need larger high-quality studies for classical psychedelics and MDMA. Ketamine studies should pay more attention to existential dimensions of well-being and the psychotherapeutic context of the treatment