Three-column Model Research Articles

Improved Harmony Search Algorithm for Enhancing Efficiency and Quality in Optimization of the Distillation Process.

Reducing production costs is one of the main objectives of process intensification; in this work, production costs of the distillation process are reduced by reducing equipment size and utility consumption from the perspective of process optimization to achieve the purpose of process intensification. The application of intelligent optimization algorithms in the optimization process of distillation is vital to achieving high efficiency and low costs. Combining the harmony search algorithm with the characteristics of distillation optimization, a new distillation harmony search algorithm (DHSA) was proposed, which includes the self-adaptive adjustment of parameters, roulette selection strategy, and ratio optimization strategy. Benefiting from the DHSA, the optimal total annual cost and calculation times were remarkably reduced when compared with reported algorithms in the optimization of four distillation cases including the two-column model, three-column model, reactive distillation column model, and dividing-wall extractive distillation column model. In addition, the highest coefficient of variation of DHSA in 10 parallel calculations is 1.25%. These results indicate that DHSA has the advantages of a higher-quality solution, less computing time, and higher stability, which not only improves the optimization efficiency and quality but also inspires the optimization strategies for other algorithms.

No-reference stereoscopic image quality assessment using a multi-task CNN and registered distortion representation

Scene discrepancy between the left and right views presents more challenges for image quality assessment (IQA) of stereoscopic images as opposed to monocular ones. Existing no-reference stereoscopic IQA (NR-SIQA) metrics cannot achieve a good performance on asymmetrically distorted stereoscopic images. In this paper, we propose an NR-SIQA index that first addresses scene discrepancy by means of image registration. It then uses a registered distortion representation based on the left and registered right views to represent the distortion in the stereoscopic image. Because different distortion types influence image quality differently, a multi-task convolutional neural network (CNN) is employed to learn image quality prediction and distortion-type identification simultaneously. We first design a one-column multi-task CNN model, that learns from the registered distortion representation. Then, we extend the one-column model to a three-column model, which also learns from the left and right views. Our experimental results validate the effectiveness of the proposed registered distortion representation and multi-task CNN architecture. The proposed one- and three-column models outperform the state-of-the-art NR-SIQA metrics, especially for asymmetrically distorted stereoscopic images.

Classifications in Brief: AO Thoracolumbar Classification System.

Classifications in Brief: AO Thoracolumbar Classification System.

Stability of the Subaxial Spine after Penetrating Trauma: Do Classification Systems Apply?

Objective Blunt spinal trauma classification systems are well established and provide reliable treatment algorithms. To date, stability of the spine after civilian gunshot wounds (CGSWS) is poorly understood. Herein, we investigate the validity of trauma classification systems including the Thoracolumbar Injury Classification and Severity Score (TLICS), Subaxial Cervical Spine Injury Classification and Severity Score (SLIC), and Denis' three-column model when applied to spinal penetrating trauma from gunshots, while secondarily evaluating stability of these injuries. Methods Gunshot injuries to the spine were identified from an institutional database from ICD-nine codes. Trauma scorings systems were applied using traditional criteria. Neurologic compromise and spinal stability were evaluated using follow-up clinic notes and radiographs. Results Thirty-one patients with CSGSW were evaluated. There was an equal distribution of injuries amongst the spinal levels and spinal columns. Twenty patients had neurological deficits at presentation. Eight patient had a TLICS score >4. Three patients had a SLIC score >4. One patient had surgical treatment. Nonoperative treatment did not lead to spinal instability or adverse outcomes in any cases. The posterior column had a high correlation with neurologic compromise, though not statistically significant (p=.118). Conclusions The TLICS, SLIC, and three-column classification systems cannot be applied to CSGSW to quantify injury severity, predict outcomes, or guide treatment decision-making. Despite significant neurologic injuries and disruption of multiple spinal columns, CSGSW do not appear to result in unstable injuries requiring operative intervention. Further research is needed to identify the rare spinal gunshot injury that would benefit from immediate surgical intervention.

Four-Corner Concept: CT-Based Assessment of Fracture Patterns in Distal Radius

Operative treatment using plate fixation is an important adjunct in the treatment of distal radius fractures, although the evidence for its superiority over other modalities remains limited. We propose a new concept for fractures of the distal radius, based on the three-column model of the distal radius, and on the expanding knowledge about the different fracture patterns obtained by evaluation of the distal radius by computed tomographic (CT) scan. All fracture types can be characterized by subdividing the wrist joint into four corners, each with its own characteristics in terms of mobility, stability, and transfer of forces in the intact distal radius. Recognition of the specific fracture types based on this four-corner concept enables a tailored approach to treatment.

Design and Control of Dividing-Wall Column for the Synthesis of n-Propyl Propionate by Reactive Distillation

In this work, a reactive dividing-wall column (R-DWC) for the synthesis of n-propyl propionate was investigated by demonstrating its design and control. Sensitivity analysis of whether the vapor split ratio (αv) can maintain the product purities was studied before the minimum TAC was established. The results show that the R-DWC can save 12.4% of the energy consumption and 16.4% of the minimum total annual cost (TAC) compared with the two-column design. After that, two control structures for the R-DWC as a three-column model were considered. The improved control structure can solve the problem of disturbances and maintain the product purities close to the set points with small deviations and short settling times.

Design and Control of Dividing-Wall Column for tert-Butanol Dehydration System via Heterogeneous Azeotropic Distillation

In this Article, a three-column model of azeotropic dividing-wall column (A-DWC) for heterogeneous azeotropic distillation (HAD) is investigated by demonstrating the design and control of tert-butanol (t-butanol) dehydration using cyclohexane as entrainer. Significant energy consumption savings of 23.80% and a minimal total annual cost (TAC) reduction of 19.93% between the optimum A-DWC design and the original two-column design can be obtained, respectively. Sensitivity analysis of whether the liquid split ratio (βL) can be a manipulated variable to maintain the product purities is conducted before the control structure for the A-DWC is established. Meanwhile, with two reboiler duties (QRs) still preserved in the A-DWC, the proposed control structure can solve disturbance issues and maintain the product purities very close to the set points with small deviation and short settling time.

Airway Assessment Based on a three Column Model of Direct Laryngoscopy

Airway assessment has remained a problematic area, largely due to the low sensitivities, specificities and/or positive predictive values of most bedside tests. In this paper a structured overview of the common preoperative airway assessment tests is presented, based on a model for direct laryngoscopy that has been previously described. This model is composed of three columns: anterior middle and posterior The anterior column tests are classified into the assessment of volume and compliance of the submandibular space, the range of movement of the temporomandibular joints and the flexibility of the stylohyoid ligament. Reductions in volume of the anterior column may be absolute or relative. An absolute reduction may occur with shortening of either the incisor-hyoid distance, the temporomandibular joint-incisor distance or the temporomandibular joint-temporomandibular joint distance. A relative reduction may be seen with either prominent upper front incisors or large tongues. Testing of the middle column includes a history and physical examination of the upper respiratory system, imaging of the airway (such as X-ray, computed tomography scans and/or magnetic resonance imaging scans) and nasopharyngoscopy. The posterior column may be assessed by the range of movement of the neck, especially the range of extension of the occipito-atlanto-axial complex. By integrating common tests of the anterior middle and posterior columns within this three-column model, the practitioner may be better positioned to understand the complexity of direct laryngoscopy in both normal and difficult airway scenarios.

Distale Radiusfraktur: neue Konzepte als Basis für die operative Therapie

New advances in the biomechanics and pathomechanics of distal radius fractures as well as new generations of plates and improved surgical approaches now make possible the stable management and early functional rehabilitation not only of simple but also of complicated distal radius fractures according to the principles for articular and juxta-articular fractures. Especially for complex articular fractures, the fracture patterns are so heterogeneous that an individual surgical treatment strategy must be developed for each case. The preoperative clarification of articular fractures with computed tomography is particularly useful for planning surgery. Mental exposition with the three-column model and pathomechanics is an important prerequisite for understanding this type of injury and the appropriate choice of operative technique. A decisive factor for success is the subtle surgical procedure in approaching and handling the fine plates.

Positive practice in family therapy.

Positive practice, a brief integrative approach to consultation with families, is described in this paper. A clear distinction is made between the stages of planning, assessment, therapy, and disengagement. Guidelines for progression from one stage to the next are provided. Frameworks for deciding who to invite to preliminary sessions and methods for planning and organizing lines of inquiry are incorporated into this approach to practice. A three-column model is used to construct formulations. The model allows therapists and clients to map information about the pattern of interaction around the presenting problem, beliefs that constrain family members from altering their roles in these problem-maintaining patterns, and factors that have predisposed family members to hold these beliefs. Positive practice offers methods for evolving new behavioral patterns and belief systems within sessions and for arranging homework tasks for clients between sessions. It also incorporates methods for dealing with resistance, for managing therapeutic crises, for convening individual sessions and broader network meetings, for disengaging from the consultation process, and for recontracting for further episodes of therapy. This evolving approach to practice draws on ideas from many traditions within the family therapy field and takes account of recent research relevant to the practice of family therapy.

The history of spinal biomechanics.

The history of spinal biomechanics has its origins in antiquity. The Edwin Smith surgical papyrus, an Egyptian document written in the 17th century BC, described the difference between cervical sprain, fracture, and fracture-dislocation. By the time of Hippocrates (4th century BC), physical means such as traction or local pressure were being used to correct spinal deformities but the treatments were based on only a rudimentary knowledge of spinal biomechanics. The Renaissance produced the first serious attempts at understanding spinal biomechanics. Leonardo da Vinci (1452-1519) accurately described the anatomy of the spine and was perhaps the first to investigate spinal stability. The first comprehensive treatise on biomechanics, De Motu Animalium, was published by Giovanni Borelli in 1680, and it contained the first analysis of weight bearing by the spine. In this regard, Borelli can be considered the "Father of Spinal Biomechanics." By the end of the 19th century, the basic biomechanical concepts of spinal alignment and immobilization were well entrenched as therapies for spinal cord injury. Further anatomic delineation of spinal stability was sparked by the anatomic analyses of judicial hangings by Wood-Jones in 1913. By the 1960s, a two-column model of the spine was proposed by Holdsworth. The modern concept of Denis' three-column model of the spine is supported by more sophisticated testing of cadaver spines in modern biomechanical laboratories. The modern explosion of spinal instrumentation stems from a deeper understanding of the load-bearing structures of the spinal column.

Computerized tomography of injury to the thoracolumbar spine

We have reviewed the appearances of 35 patients with 51 fractures of the thoracic and lumbar spine who were seen over the past 3 years; all received plain film radiography and computerized tomography (CT). The types and distribution of fractures are similar to those in series already reported. The severity of each fracture can be described using a three-column model for the functional anatomy of the spine. The liability to orthopaedic instability or late neurological damage can be accurately assessed by computerized tomography. CT demonstrates many fractures of parts of vertebrae not seen on plain films. We propose a classification which is clinically relevant and simple.

Inhomogeneities in the solar atmosphere from the CaII infra-red lines

From a time sequence of high dispersion spectra taken by Evans, the solar fine structures are studied in the Caii infra-red triplet. The Doppler shifts and the intensity fluctuations in different points of the profiles are converted into fluctuations of the model atmosphere. A weighting function method is worked out in that purpose. The theoretical line profiles are computed in non LTE from a program written by Dumont. The results are arranged in two parts: (1) Low temporal frequencies. A three-column model describes the steady field of temperature, microturbulence and radial velocities fluctuations in the photosphere-chromosphere transition zone. (2) Oscillations. The propagation of waves is considered in the three above-mentioned columns. The oscillation amplitudes seem statistically larger in the hot column. The vertical phase velocity is very large, even for frequencies higher than the cut-off frequency of acoustic waves. Velocity and temperature fluctuations are connected by different curves of phase-lags and amplitude ratios suggesting a short relaxation time of the temperature fluctuations in the low chromosphere.