A PSO-GRNN model for railway freight volume prediction: empirical study from China

Purpose: The purpose of this paper is to propose a mathematical model for the prediction of railway freight volume, and therefore provide railway freight resource allocation with an accurate direction. With an accurate railway freight volume prediction, railway freight enterprises can integrate the limited resources and organize transport more reasonably. Design/methodology/approach: In this paper, a PSO-GRNN model is proposed to predict the railway freight volume. In this model, GRNN is applied to carry out the nonlinear regression analysis and output the prediction value, PSO algorithm is applied to optimize the GRNN model by searching the best smoothing parameter. In order to improve the performance of PSO algorithm, time linear decreasing inertia weight algorithm and time varying acceleration coefficient algorithm are applied in the paper. Originality/value: A railway freight volume prediction index system containing seventeen indexes from five aspects is established in this paper. And PSO-GRNN model constructed in this paper are applied to predict the railway freight volume from 2007 to 2011. Finally, an empirical study is given to verify the feasibility and accuracy of the PSO-GRNN model by comparing with RBFNN model and BPNN model. The result shows that PSO-GRNN model has a good performance in reducing the prediction error, and can be applied in actual production easilyPeer Reviewe

From Click to Click and Release , Using Inverse Electron Demand Diels-Alder Reaction for Chemical and Medicinal Applications

Substituted tetrazines have been found to undergo facile inversed electron demand Diels-Alder reactions with “tunable” reaction rates. By varying the substituents on tetrazine, cycloaddition rate variations of over 200 fold have been achieved with the same dienophile. Coupled with the availability of different dienophiles, such as norbornene, the reaction rate difference can be over 14,000 folds. These substituted tetrazines can be very useful for selective labeling under different conditions. This finding paves the way to utilize tetrazine conjugation reactions for not only DNA but also stage labeling work. Carbon monoxide (CO) belongs to the gasotransmitter family of signalling molecules in the mammalian systems with importance on par with that of NO and H2S. Studies have shown that endogenous production of CO has anti-inflammatory, anti-proliferative, and anti-apoptotic effects in mammalian system. Besides of the conventional metal-based carbon monoxide releasing molecules (CORMs) to deliver CO for therapeutic purposes, organic CO prodrugs represent a new direction. Here we report the “click and release” approached to release CO. Unlike the metal-based CORMs, our system does not contain transition metal and liberates CO with controllable manner and possesses potential tunable releasing rate property under physiological conditions

Bi-Objective Modelling for Hazardous Materials Road–Rail Multimodal Routing Problem with Railway Schedule-Based Space–Time Constraints

The transportation of hazardous materials is always accompanied by considerable risk that will impact public and environment security. As an efficient and reliable transportation organization, a multimodal service should participate in the transportation of hazardous materials. In this study, we focus on transporting hazardous materials through the multimodal service network and explore the hazardous materials multimodal routing problem from the operational level of network planning. To formulate this problem more practicably, minimizing the total generalized costs of transporting the hazardous materials and the social risk along the planned routes are set as the optimization objectives. Meanwhile, the following formulation characteristics will be comprehensively modelled: (1) specific customer demands; (2) multiple hazardous material flows; (3) capacitated schedule-based rail service and uncapacitated time-flexible road service; and (4) environmental risk constraint. A bi-objective mixed integer nonlinear programming model is first built to formulate the routing problem that combines the formulation characteristics above. Then linear reformations are developed to linearize and improve the initial model so that it can be effectively solved by exact solution algorithms on standard mathematical programming software. By utilizing the normalized weighted sum method, we can generate the Pareto solutions to the bi-objective optimization problem for a specific case. Finally, a large-scale empirical case study from the Beijing–Tianjin–Hebei Region in China is presented to demonstrate the feasibility of the proposed methods in dealing with the practical problem. Various scenarios are also discussed in the case study

Correction: Sun, Y.; et al. Bi-Objective Modelling for Hazardous Materials Road–Rail Multimodal Routing Problem with Railway Schedule-Based Space–Time Constraints. Int. J. Environ. Res. Public Health 2016, 13, 762

Bi-Objective Modelling for Hazardous Materials Road–Rail Multimodal Routing Problem with Railway Schedule-Based Space–Time Constraints.[...

A PSO-GRNN model for railway freight volume prediction: empirical study from China

Purpose: The purpose of this paper is to propose a mathematical model for the prediction of railway freight volume, and therefore provide railway freight resource allocation with an accurate direction. With an accurate railway freight volume prediction, railway freight enterprises can integrate the limited resources and organize transport more reasonably. Design/methodology/approach: In this paper, a PSO-GRNN model is proposed to predict the railway freight volume. In this model, GRNN is applied to carry out the nonlinear regression analysis and output the prediction value, PSO algorithm is applied to optimize the GRNN model by searching the best smoothing parameter. In order to improve the performance of PSO algorithm, time linear decreasing inertia weight algorithm and time varying acceleration coefficient algorithm are applied in the paper. Originality/value: A railway freight volume prediction index system containing seventeen indexes from five aspects is established in this paper. And PSO-GRNN model constructed in this paper are applied to predict the railway freight volume from 2007 to 2011. Finally, an empirical study is given to verify the feasibility and accuracy of the PSO-GRNN model by comparing with RBFNN model and BPNN model. The result shows that PSO-GRNN model has a good performance in reducing the prediction error, and can be applied in actual production easil

A PSO-GRNN model for railway freight volume prediction: empirical study from China

Purpose: The purpose of this paper is to propose a mathematical model for the prediction of railway freight volume, and therefore provide railway freight resource allocation with an accurate direction. With an accurate railway freight volume prediction, railway freight enterprises can integrate the limited resources and organize transport more reasonably. Design/methodology/approach: In this paper, a PSO-GRNN model is proposed to predict the railway freight volume. In this model, GRNN is applied to carry out the nonlinear regression analysis and output the prediction value, PSO algorithm is applied to optimize the GRNN model by searching the best smoothing parameter. In order to improve the performance of PSO algorithm, time linear decreasing inertia weight algorithm and time varying acceleration coefficient algorithm are applied in the paper. Originality/value: A railway freight volume prediction index system containing seventeen indexes from five aspects is established in this paper. And PSO-GRNN model constructed in this paper are applied to predict the railway freight volume from 2007 to 2011. Finally, an empirical study is given to verify the feasibility and accuracy of the PSO-GRNN model by comparing with RBFNN model and BPNN model. The result shows that PSO-GRNN model has a good performance in reducing the prediction error, and can be applied in actual production easilyPeer Reviewe

The modified ultrasound-guided distal-to-proximal carpal tunnel injection with median nerve hydrodissection: A retrospective safety review of 827 procedures

Objective: The aim of this report is to describe a new ultrasound guided technique for carpal tunnel injection and median nerve hydrodissection using distal to proximal approach. Methods: From 2015 to 2019, 827 consecutive injections by distal-to-proximal approach were included using coding information to check for post-procedural skin hypopigmentation, hematoma, seroma, nerve injury, or vascular injury. Results: There were no occurrences of post-procedural skin-hypopigmentation, hematoma or seroma formation, or neurovascular injury. Conclusions: The distal approach carpal tunnel injection is a safe and effective method. It may directly inject the medication into carpal tunnel to avoid skin hypopigmentation from steroid side effect with previous report method, also it may release adhesion of median nerve with surrounding soft tissue by hydrodissection. It helps median nerve compression at outlet of carpal tunnel

A cadaveric study using the ultra-minimally invasive thread transection technique to decompress the superficial peroneal nerve in the lower leg

BACKGROUND: After successful applications of the ultra-minimally invasive thread transecting technique (Guo Technique) for both thread carpal tunnel release and thread trigger finger release, we hypothesized that this technique could be used for superficial peroneal nerve release in the lower leg by selective crural fasciectomy. This study is aimed at testing the operative feasibility of performing the thread superficial peroneal nerve release (TSPNR) procedure in cadavers. METHODS: The TSPNR procedure was performed on 15 fresh frozen cadaveric lower-extremity specimens under ultrasound guidance. All cadaveric specimens were dissected and visually assessed immediately after the procedures. RESULTS: All 15 legs demonstrated a complete transection of the crural fasciae along the course of the superficial peroneal nerve (SPN) including where it penetrated and traversed the crural fascia. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 20 min. CONCLUSION: This cadaveric study demonstrated that the technique of TSPNR was accurate, reliable, and feasible while causing no injury to adjacent neurovascular structures and avoiding having to make a skin incision. Further studies are warranted to verify the results of this study before implementing this new technique in the clinical setting