bluuebunny/crossref_metadata_2025 huggingface dataset:
Fully Automatic Segmentation and Landmarking of Hip CT Images
Authors: Zheng Guoyan
Published: September 2020

We present a fully automatic method of segmenting and landmarking hip CT images for planning of Total Hip Arthroplasty (THA). Our method consists of two stages, i.e., the segmentation stage and the landmarking stage. At the segmentation stage, a multi-atlas segmentation constrained graph method is employed to fully automatically segment both the pelvis and the bilateral proximal femurs from the input CT data. The segmentation stage is followed by the landmarking stage, where a set of pre-defined landmarks are transferred from generic models of the associated hip structures to the input CT space via non-rigid registrations in order to compute a set of functional parameters that are relevant to planning of THA. Evaluated on 20 hip patients, we computed both the segmentation accuracy and the landmarking accuracy. An average segmentation error of 0.38 ± 0.25 mm and 0.49 ± 0.22 mm was found for the hemi-pelvis and for the proximal femurs, respectively. For 3D landmarking, a mean error of 1.58 ± 0.87 mm and 0.46 ± 0.39 mm was found for the acetabular rim center and the acetabular rim radius, respectively; a mean error of 0.74±0.45o was found for the orientation of the anterior pelvic plane; and a mean error of 3.14 ± 1.90 mm and 2.04 ± 1.61 mm was found for the femoral head center and the femoral offset, respectively.
Predicting Cementless Stem Fixation in Total Hip Arthroplasty Using Radiodensity Mapping
Authors: Cherukuri Teja , Madurawe Chameka , Pierrepont Jim , Bare Jonathan , McMahon Stephen , Shimmin Andrew
Published: September 2020

Femoral component loosening due to poor fixation is a common failure mode in cementless total hip arthroplasty (THA). We sought to develop a technique to predicted femoral stem fixation using pre-operative CT.

Forty-nine patients requiring THA received pre-operative CTs as part of Corin OPSTM 3D dynamic planning. All patients received a taper wedged blade stem (TriFitTM TS, Corin UK) implanted through a posterior approach. Post-operatively, patients received an immediate CT and AP x-ray and a 1-year follow-up x-ray. The distance between the most superior point of the greater trochanter and the shoulder of the stem was measured and scaled using the known cup diameter on both the immediate and 1- year follow-up x-rays. The difference was recorded as stem subsidence. Subsidence greater than 4mm was deemed clinically relevant. The precise placement of the stem determined by registering the known 3D implant geometry to the post-op CT was virtually implanted back into the pre-operative OPSTM planning software. A colour map of the bone density at the stem/bone interface using the Hounsfield Units (HU) of each CT pixel was generated. Blue represents low density bone transitioning through to green and then red.

Mean stem subsidence was 1.8mm (0 to 11.1mm). Five patients had clinically relevant subsidence. Significant areas of blue and green around the proximal portion of the stem was observed in high subsidence stems when compared to the stems with minimal subsidence.

Using the HU of the CT scan as an indicator for bone density, we were able to predict poor implant fixation and subsequent subsidence in a taper wedge stem.
Assessing the Effect of Curing Conditions, Specimen Type, and Superabsorbent Polymers in Compressive Strength and Abrasion of Pervious Concrete
Authors: Daddino Dennis , Gaedicke Cristian , Castronovo Fadi , Motavalli Saeid , Liguori David
Published: September 2020

The effect of curing conditions, specimen type, and the use of super absorbent polymers on the Compressive Strength and Abrasion of Portland Cement Pervious Concrete was evaluated. Five different mixtures, using different water/cement ratios, and the addition of polypromancic based acid and polyacrylate based super absorbent polymers were tested. Half of the specimens were cured in a temperature-controlled room at higher temperature and lower humidity to simulate field conditions. Specimens that were cured in these harsher conditions showed reduced compressive strength in the range of 34% to 35% for cast cylinders, and 27% to 67% for cores when compared to specimens cured under ideal conditions in the lab. These samples also had 3.14 to 3.2 times the abrasion damage compared to laboratory cured samples of similar porosities.
Exploring the Synergy Between Lean Construction and Flash Track Implementation
Authors: Pishdad-Bozorgi Pardis , Kumar Sooraj
Published: September 2020

Speed-driven projects require extensive planning and coordination for their successful execution within the specified time and cost. With an increasing demand for flash track execution, more efficient ways for project implementation is needed. Lean construction is having a profound impact on the construction industry, which is perceived to be suffering from cost and schedule overruns. This review paper investigates the use of various lean tools and principles in flash track projects and if there is any synergy between lean and flash track projects to improve productivity and schedule performance. Through rationalizations and with the help of case studies and theoretical evidence found in literature, eleven lean tools and eight lean principles have been analyzed for their synergy with flash track construction. The results indicate that all except one lean tool (Just in Time) and one lean principle (reduce inventory) facilitate successful implementation of flash track project.
The Influence of Immediate Urban Surroundings on Energy Performance of Historical Buildings
Authors: Dursun Onur , Durmuslar Feyza , Olmez Duhan
Published: September 2020

High-density urban areas contain large number of historical buildings whose structures and artistic values are protected by regulations. This restricts the improvements can be made to building envelope to reduce energy demand of historical buildings. Therefore, immediate urban surroundings (IUS) may play a central role on energy performance of historical buildings (EPHB). Yet, literature has provided little or no evidence, so far. To address the gap, the current experimental inquiry aims to test the significance of IUS’s influence on the EPHB. To achieve, historical structure in hot- humid climate was selected and surveyed thoroughly. Control and intervention cases were considered to measure the influence IUS. The control case corresponds to the former state of IUS; whereas the intervention described as the IUS which includes a recently built office block with reflective glass façade. The numerical result obtained from computational thermal simulations were used for comparison. Accordingly, the increase in heating demand substantially surpassed the decrease in cooling demand for the case under study. Therefore, a significant increase in total energy demand was observed in the presence of intervention. In addition, the energy performance of the individual volumes located in the lower floors presented higher fluctuations due to intervention’s shading effect.
Frequency of soft-tissue releases and their effect on patient reported outcomes in robotic-assisted TKA.
Authors: Plaskos Christopher , Wakelin Edgar , Shalhoub Sami , Lawrence Jeffrey , Keggi John , Koenig Jan , Ponder Corey , DeClaire Jeffrey
Published: September 2020

Soft tissue releases are often required to correct deformity and achieve balance in total knee arthroplasty (TKA). However, releasing soft tissues can be subjective, highly variable and is perceived as an ‘art’ in TKA. The objective of this study was to compare the rate of soft tissue release required to achieve a balanced knee in tibial-first gap- balancing versus conventional, measured resection TKA, and its effect on outcomes.

Soft tissue releases were documented and reviewed in 1256 robotic-assisted gap- balancing and 85 robotic-assisted measured-resection TKAs. Knees were stratified by coronal deformity (varus: >2° varus; valgus: >2° valgus). Rates of releases were compared between the two groups and literature. A subset of these patients were also enrolled in a prospective study. KOOS outcomes were captured pre-operatively and at 6M post TKA.

The frequency of soft tissue release was significantly lower in the robotic gap- balancing group, with 21% of knees requiring release versus 40% (p=0.001) in the robotic measured resection group and 67% (p<0.001) for conventional measured resection. Pre-operative KOOS scores were similar between groups, however 6M scores showed a significant improvement in QOL, Sports and Symptoms scores in knees not released.

Robotic assisted TKA with predictive gap balancing was found to reduce the number of releases across all coronal angles compared to conventional instruments. Furthermore, performing a soft tissue release rather than bone resection to achieve balance, correlated with worse outcomes. Further research is required to understand when imbalance should be corrected with bone resection adjustment versus soft tissue release.
Data-driven Assessment of Market Share Growth Factors of Union Electrical Contractors in the U.S.
Authors: Said Hisham , Deshmukh Ajay
Published: September 2020

Building trade unions have had an instrumental role in advocating for worker welfare, training, health and safety in the U.S. construction industry. Since 1970s, the membership and market share of trade unions have dramatically declined, and there is no clear understanding and previous scholarly assessment of the drivers of such decline. This study provides a data-driven assessment of the market share controlling factors of the U.S. electrical trade unions and their signatory contractors. The study depended on collecting a large amount of data from the union electrical contractor organization, government census agencies, surveys, and interviews of electrical contractors. Union market share trends were found to be correlated to the use of higher crew ratios and the adoption of non-apprenticeship worker classifications.
Leveraging Construction Higher Education to Expose a Broader Audience to the Construction Industry in the United States
Authors: Bigelow Ben F. , Perrenoud Anthony J.
Published: September 2020

The workforce shortage in construction is a serious issue. With a plethora of initiatives emerging in the past few years to attract more individuals to careers in construction, a question has arisen as to whether the initiatives reach an audience outside of those who would go to work in construction anyway. This project sought to develop an intervention that would expose a broader audience to construction topics, and related careers in construction, through a course in a construction higher education program. Students in the construction higher education program created lesson plans that would be employed in public school classrooms and fit in the required curriculum, thereby reaching all students and not just those already inclided toward a career in construction. The results suggest the course was successful in achieving its initial objectives, however long term impacts on the workforce shortage are not yet known.
Development of a Required Service-Learning Course: Lessons Learned and Stakeholders’ Perceptions
Authors: Redden Lauren W. , Bugg Robert A.
Published: September 2020

There is a growing movement for universities to include high-impact educational practices. This study explores the implementation and efficacy of one such practice in a construction management undergraduate program. During a recent curriculum revision, faculty decided to include a required service-learning course in the curriculum to enhance both student learning and civic engagement. The course assimilates all components of the construction process. Key assessments of the course include: written proposal & preconstruction presentation to the owner, project update reports, a mid-semester site inspection, and a final presentation accompanied by a written reflection. Students and owners voluntarily completed surveys at the end of the semester to determine the elements requiring improvement, elements that should remain unchanged, and the perceived knowledge gain through the experience. The results indicate the project owners were satisfied and the students acknowledged learning benefits. Owners, students and faculty all noted major challenges/frustrations with the course and the need for improvement. The paper summarizes the data to evaluate the efficacy of the required course and highlights lessons learned to improve the course. Dissemination of the results may be useful in starting or improving service-learning courses at other institutions.
Using a robotics path planning algorithm to assess the risk of mobile bearing dislocation in lateral unicompartmental knee replacement.
Authors: Yang Irene , Gammell Jonathan D. , Murray David W. , Mellon Stephen J.
Published: September 2020

Dislocation of the bearing occurs in 1 - 6% of Oxford Domed Lateral (ODL) mobile bearing unicompartmental knee replacements (UKRs). Dislocations occur in flexion as the lateral ligaments are lax in this position allowing the knee to distract. Anterior and posterior dislocations are rare: clinically, their dislocation rates are acceptable. Most dislocations tend to occur medially, with the bearing sitting on top of the tibial wall. Using robotics path planning algorithms and a modified Open Motion Planning Library (OMPL) Graphical User Interface (GUI), a dislocation analysis tool was developed to assess the minimum amount of vertical distraction of the femoral component relative to the tibial component required for the mobile bearing to dislocate. In the tool, the Rapidly- exploring Random Trees (RRT) algorithm was applied to the mobile bearing, which enabled autonomous movement of the bearing from a non-dislocated to a dislocated position. Testing increased the relative distance between the femoral component and the tibial component: vertically (2-6 mm) and mediolaterally (0-4 mm) in 0.25 mm increments resulting in a total of 289 configurations. For each configuration, the tool assessed whether mobile bearing dislocation was possible (either medially, laterally, anteriorly or posteriorly). For each mediolateral translation distance, the minimum vertical distraction required for dislocation was recorded. To validate the tool, dislocation results were compared to measurements taken using a custom-built mechanical rig. The minimum amount of distraction required for medial dislocation was similar for the dislocation analysis tool (3.75 to 4.75 mm) as compared to a custom-built mechanical rig (2.5 to 4 mm). The amount of distraction for a medial dislocation was much smaller than that for an anterior or posterior dislocation (6 to 6.25 mm). This explains why medial dislocations are more common. Future work will use this tool to inform implant design, with the aim to reduce the risk of medial dislocation to match that of anterior/posterior dislocation, which is clinically acceptable.
Insights into Education System for Sustainable Development: The case of UCEM, UK
Authors: Thakore Renuka , Williams Aled
Published: September 2020

‘Education for Sustainable Development’ (ESD) drives priority to aligning education programmes for convergence of Sustainable Development Goals (SDGs) and Education agendas. This paper argues that, to this end, the importance of strategic, tactical and operational level changes and sustaining the human and material resources used to transform any kind of learning environments, should be factored into all institutional-wide strategies. In other words, this should be an integral aspect of the implementation of sustainability elements in institutional-wide activities. However, ideally, to fully establish the foundation for Sustainability, the range of activities by which ESD can be delivered should not be restricted but should be extended to building a society that values peace, equality, human rights, gender, environment and cultural diversity. This would assist furthering SDGs; however, to be effective, this approach requires the incorporation of a process like NUS Responsible Future Certification. The scope of this paper will therefore outline what whole-institution collaborative approach is, and then why it is relevant, considering how it may be used to contribute to a more sustainable future of the built environment education system. Document analysis research methodology was used to inform a theoretical conceptual framework for education system for sustainable development.
Change in 2D and 3D femoral head coverage after curved periacetabular osteotomy
Authors: Uemura Keisuke , Okamoto Masashi , Tokunaga Kunihiko , Anderson Andrew
Published: September 2020

Femoral head coverage in patients with hip dysplasia (DDH) is often quantified using 2D parameters, including the lateral center edge angle (LCEA) and anterior center edge angle (ACEA). However, only moderate correlations have been observed between the 2D coverage and 3D coverage. The purposes of this study were to: 1) quantify the change in 3D head coverage after curved periacetabular osteotomy (CPO), and 2) analyze the relationship between 2D and 3D head coverage preoperatively and postoperatively. Forty-three hips of 39 female cases (age: 37±10 years) who underwent CPO were analyzed. 2D coverage was quantified using the LCEA and ACEA from CT images. 3D coverage was quantified in the anterior, superior, posterior, inferior head regions. 3D measurements were performed both pre- and post-operatively and were correlated to the measurements of 2D coverage to study interactions. Preoperative 3D percent coverage in each head region was 17.8±6.7%, 36.2±7.7%, 57.6±10.2%, and 15.3±6.4% for the anterior, superior, posterior, and inferior region, respectively. Postoperatively, 3D coverage in the anterior and superior regions increased to 23.4% and 53.7%, respectively while a significant decrease was found for the posterior and inferior regions (all p<0.01). When 3D and 2D coverage was correlated, significant positive correlation was found between the 3D superior coverage and the LCEA both preoperatively (r=0.72, p<0.01) and postoperatively (r=0.67, p<0.01). However, no correlation was found between the 3D anterior coverage and the ACEA, which became significant in the postoperative period (r=0.69, p<0.01). Results indicate that preoperative anterior coverage for patients with DDH should be evaluated three-dimensionally.
The Impact of a Studio-based Model on Construction Students’ Perceptions
Authors: Barlow Philip , Rokooei Saeed
Published: September 2020

A Studio-based learning model is a common instructional model in architecture, art, and design-based programs. The features of this type of learning model are attracting the attention of educators in many disciplines including construction education. However, applying this educational model in the field of construction is still new and needs more investigation and assessment. One key way to evaluate the effectiveness of this model and to inform ways of improving it is accessing students’ perceptions where it is currently being practiced. The main objective of this study was to explore how construction students perceive a studio-based model in the curriculum. A quantitative research method was designed and employed to identify challenges, potentials, and the importance of an existing studio-based model approach. A group of senior construction management students at Cal Poly, participated in this study in the Spring of 2019. The results indicated an enhanced opportunity for the class to work and learn together through teamwork, collaboration, and group discussion was a significantly positive studio-based outcome. Student perceptions were also analyzed on a studio-based models’ effectiveness, optimization, and learning. The results of this study can be used as a framework for preliminary design and implementation stages of a studio-based learning model at other universities and enhance ones currently using it.
Topics for Collaborative Research in AEC: Pilot Findings from a Sustainable Perspective
Authors: Debs Luciana , Gusmao Brissi Sara
Published: September 2020

Recent improvements in the AEC industry, such as Building Information Modeling (BIM) and lean construction and sustainability, require that the design and construction process be approached from a holistic and collaborative manner. From an academic perspective, collaboration also is an important teaching and research component that allows for a well-rounded understanding of the AEC industry. However, very little research has been performed on collaboration in the AEC disciplines, specifically interdisciplinary collaboration. As a starting point, this paper focuses on academic collaboration in journal publications related to sustainability and building performance. The authors provide bibliometric and thematic analyses of three 2018 research publications related to building performance and written by faculty affiliated with construction departments. The main goal of the paper is to provide preliminary findings about which AEC disciplines were included and which themes were prevalent in collaborative publications. Preliminary findings indicated themes related to performance analysis of buildings and / or building components; indoor environmental quality; decision-making and evaluation methods; and life cycle assessment. Results can be used to identify potential areas that are conducive to collaborative work between construction and other AEC disciplines in order to stimulate more interdisciplinary collaboration within AEC research.
The Effect of Coronal and Axial Femoral Component Rotation on Midflexion Laxity and Patient Reported Outcomes in Total Knee Arthroplasty
Authors: Wakelin Edgar , Shalhoub Sami , Lawrence Jeffrey , Keggi John , Randall Amber , Ponder Corey , DeClaire Jeffrey , Koenig Jan , Plakos Christopher
Published: September 2020

Joint balance in total knee arthroplasty (TKA) has traditionally focused on achieving a tight symmetric extension gap and rectangular or trapezoidal gaps in flexion. This study sought to investigate the effect of femoral and tibial coronal rotation and femoral axial rotation on midflexion coronal joint balance and patient outcomes.

A prospective multi-center study was performed with a mixture of tibia-first gap-balancing and femur-first approaches were performed using the Corin OMNIBotics robot-assisted TKA platform with APEX implant components. Coronal and axial femoral and tibial resections were recorded by the platform. Medial and lateral joint gaps were recorded while applying a computer-controlled load to the joint throughout flexion during trialing using the Corin BalanceBot device. In addition, 1-year Knee Injury and Osteoarthritis Outcome Score (KOOS) and PROMIS-10 global health scores were collected.

231 surgeries were identified: 66.9±8.1 years, 31.4±4.8 kg/m2 and 57% female (121) with a mean pre-operative HKA angle of 4.5±5.2° varus. A significant correlation was found between the medio-lateral (ML) joint gap difference in midflexion and both extension and flexion joint line (p=0.003, r2=-0.20, p=0.001, r2=-0.22, respectively). A significant correlation was found between midflexion ML imbalance and KOOS stiffness questions at 3 M and 6 M post-op (r2=-0.15, p=0.036, r2=-0.18, p=0.013), in which a more balanced knee correlated with improved outcomes.

Treating flexion and extension joint balance in isolation may not capture the effect on midflexion laxity. Component placement should take in to account the effect on joint gaps throughout flexion to target optimal joint balance.
Guaranteed phase synchronization of hybrid oscillators using symbolic Euler's method (verification challenge)
Authors: Jerray Jawher , Fribourg Laurent , André Étienne
Published: September 2020

The phenomenon of phase synchronization was evidenced in the 17th century by Huy- gens while observing two pendulums of clocks leaning against the same wall. This phe- nomenon has more recently appeared as a widespread phenomenon in nature, and turns out to have multiple industrial applications. The exact parameter values of the system for which the phenomenon manifests itself are however delicate to obtain in general, and it is interesting to find formal sufficient conditions to guarantee phase synchronization. Using the notion of reachability, we give here such a formal method. More precisely, our method selects a portion S of the state space, and shows that any solution starting at S returns to S within a fixed number of periods k. Besides, our method shows that the components of the solution are then (almost) in phase. We explain how the method applies on the Brusselator reaction-diffusion and the biped walker examples. These examples can also be seen as “challenges” for the verification of continuous and hybrid systems.
Post-operative Virtual Range of Motion in Robotic-assisted THA Patients to determine Pre-operative Simulation Needs
Authors: Thompson Matthew , Guttal Roopa , Darcy Shon , Alaghatta Akshay , Marcovigi Andrea , Catani Fabio
Published: September 2020

For preoperative simulations of hip range of motion to be useful in predicting complications after total hip arthroplasty (THA), the factors that could affect post-operative function must be considered including, but not limited to, bony impingement, pelvic position, and implanted vs. planned differences. This study retrospectively simulates ranges of motion to prosthetic and bony impingement of THA patients with known planned and implanted component positions and pelvic tilt to determine the factors and needs to accurately simulate range of motion preoperatively.

Twenty-two (22) anterolateral, cementless total hip arthroplasties were performed using robotic-arm assisted technology which allowed capture of the implanted stem version and position in addition to robotic-assisted cup placement to plan. With the known implanted positions and preoperative 3-dimentional (3D) bone models, six (6) hip maneuvers were virtually simulated in custom software. Correlations were evaluated between planned and implanted component positions, pelvic tilt, ranges of motion, and patient-reported outcomes.

Average ranges of motion to impingement were similar to those of previous simulation and navigation studies. Supine tilt varied from -10 ̊ (posterior) to 15 ̊ (anterior) with an average of 3.4±6.6 ̊. Very little correlation was seen between native or planned stem version and implanted stem version. Correlations were seen between some maneuvers such as internal rotation (IR) at 90 degrees flexion (F) (IR@90F) and combined component version and pelvic tilt. Bony impingement occurred during IR@90F in 9 of the 22cases. Pelvic tilt assessment, bony impingement detection, better prediction of implanted component position or the ability to execute a plan, such as robotically, would all provide a more accurate pre-operative simulation of the post-operative patient’s function.
Use of Knee Fractures Physical Replicas for Surgical Training and Rehearsal: Proof of Concept Study
Authors: Capodici Angelo , Parchi Paolo Domenico , Condino Sara , Carbone Marina , Ferrari Vincenzo , Pasqua Ilenia , Ferrari Mauro , Scaglione Michelangelo
Published: September 2020

In the last years also in orthopedic surgery, there was an increasing interest in the development of surgical simulators using methods of additive manufacturing combined or not with augmented reality systems (hybrid simulators). Aim of this work was to evaluate the use of a new patient’s specific tibial plateau fractures simulator for surgical training of young resident surgeons in fracture fixation with an external fixator. The simulator is a realistic knee phantom including a patient-specific replica of a fractured tibia and fibula, obtained by CT segmentation and rapid prototyping techniques. Each training session started with the presentation, and planning, of the surgical case that it was followed by the external fixation session on the simulator. At the end of each session, all participants were asked to fill out a questionnaire, concerning the phantom realism and appropriateness as a teaching modality. The results of the Likert Questionnaire indicating that there is an overall significant agreement with the phantom realism and its appropriateness as a teaching modality.

The solid model of the patient’s anatomy can faithfully reproduce the surgical complexity of the patient and it allows to generate surgical simulators with an increasing difficulty to perform structured training paths: from the "simple" case to the "complex" case. The use of simulators based on 3D models has proved to be a very useful tool both for didactic and surgical training purposes, allowing surgeons to perform a real procedure simulation outside the surgical room.
CAOS TKA Provides Improved Functional Outcomes Compared to Conventional TKA
Authors: Fan Wen , Dai Yifei , Giordano Gérard
Published: September 2020

This study examined the advantages of CAOS TKA in short-term functional outcomes compared to conventional instrumented TKA. Data were collected from a prospective, multi-center study where 334 were treated with CAOS TKA, and 461 were treated with conventional TKA. Postoperatively at 2-3 year, the CAOS cases had significantly better range of motion (ROM), KSS function, and sub-component measures of KSS function than the conventional cases. Further analysis revealed that geographic region was associated with ROM but had no significant impact on KSS function. CAOS TKA was associated with higher postoperative KSS function and its sub-component measures. The short-term results reported support the use of CAOS technology with the goals of better function.
ARCH-COMP20 Category Report: Stochastic Models
Authors: Abate Alessandro , Blom Henk , Cauchi Nathalie , Delicaris Joanna , Hartmanns Arnd , Khaled Mahmoud , Lavaei Abolfazl , Pilch Carina , Remke Anne , Schupp Stefan , Shmarov Fedor , Soudjani Sadegh , Vinod Abraham , Wooding Ben , Zamani Majid , Zuliani Paolo
Published: September 2020

This report presents the results of a friendly competition for formal verification and policy synthesis of stochastic models. It also introduces new benchmarks within this category, and recommends next steps for this category towards next year’s edition of the competition. The friendly competition took place as part of the workshop Applied Verification for Continuous and Hybrid Systems (ARCH) in Spring/Summer 2020.
A Robust Controlled Backward Reach Tube with (Almost) Analytic Solution for Two Dubins Cars
Authors: Mitchell Ian
Published: September 2020

Benchmark Proposal: We describe how a well-known backward reachability problem with nonlinear dynamics and adversarial inputs—based on a pursuit evasion game with two identical vehicles that have Dubins car dynamics—can be viewed as a robust controlled backward reach tube. The resulting set is nonconvex with a surface that is nondifferentiable in places, yet (mostly explicit) closed form solutions for points on the surface of this set have been derived based on a classical differential game analysis, and so these points can be sampled with high accuracy at arbitrary density. We propose this problem as a benchmark because few existing reachability algorithms can tackle robust controlled backward reach tubes despite their potential for proving the robust safety of systems, and this (almost) analytic solution exists against which to compare prospective solutions. We then describe some extensions to the problem to provide additional future challenges. Code is provided.
Development of the BIM Body of Knowledge (BOK) Task Definitions and KSAs for Academic Practice
Authors: Mayo Glenda , McCuen Tamera , Hannon John , Smith Deke
Published: September 2020

The BIM BOK project was a catalyst to investigate expectations and perceptions of professional BIM practices and performance outcomes. The project began in 2014 and was developed by the leadership of the Academic Interoperability Coalition (AiC). The AiC operates with the goals of improving communication and discussion concerning how academics around the world have been introducing BIM to their students (McCuen, 2014). The long-term goals of the BIM BOK project include the development of comprehensive metrics of BIM competency assessments for both industry/workforce and for academia and assists to delineate the specific tasks to roles, levels of knowledge and project phase. To date, although metrics for assessment for courses and certifications exist, there has not been a unified attempt to collect BIM competencies and requirements in one holistic framework. The AiC BIM BOK framework serves the purpose of creating a common curriculum roadmap to bridge the gap between college education outcomes and workplace performance requirements and to advance the understanding of BIM practices. Additionally, for the human resources sector, it will assist to standardize the levels of expectation for hiring practices and establish benchmarks for job task performance for emerging BIM job titles. Academics can then create the baseline performance measurement for BIM education accreditation, professional credentialing and certification. The initial phase of the BIM BOK project is complete and is now entering the next phase which includes a validation process. In an effort to summarize and market the results, the researchers have created a historical account of its development and an update on the future mission and the anticipated benefits for industry.
Can a well balanced soft tissue envelope speed up the postoperative treatment and improve clinical follow-up? A control - pilot study using a dynamic ligament balancing device based on functional stability
Authors: Paszicsnyek Thomas , Bori Edoardo , Stiegler Christoph , Innocenti Bernardo
Published: September 2020

Introduction

Worldwide, the number of TKA implants is increasing. Even if registry demonstrate that TKA as high satisfaction rate, there are still between 15 and 20% dissatisfied patients.

Materials and methods

The proper soft tissue balancing is one of the most discussed topics of the last years. We initiated a study using an electronic device („dynamic ligament balancing sensorplate“) to compare the benefit of the measurement of ligament tension, space and position in comparison to a conventional surgical procedure. Beside that, we followed the concept of functional stability, which tells us, that a tension of 40N in total is sufficient to reach proper (functional) joint stability.

This control pilot study was set up as a single surgeon, single center study and consists of 25 patients treated by the use of the sensorplate and a control group of 25 patients, treated in a conventional setup.

We used the following scores for evaluation: OKS, AKSS and FJS, preoperatively and during the FU examinations (postoperative, 6 weeks, 3 months, 6 months and 1 year)

Beside scoring, clinical examination and routine x-ray we performed an EMG testing at all FU dates.

Results

The study was performed between January 2017 and May 2019. The mean age of the patients was in average 72 years, 66 % female and 34 % male. After 1 year, results demonstrate a clear difference in the development of the postoperative situation between dynamic balanced TKA and the control one.

So, the use of such electronic device improving the soft tissue envelope stability, enable a significantly better patient FU, especially in terms of OKS

Discussion

The DLB system is a new option to value and improve the soft tissue envelope tensioning during the surgical TKA operation. It allows to measure ligament tension, slope and joint space all over the entire ROM.

Conclusion

Using an electronic device for measurement is an advanced option to improve patient satisfaction after tka. Like the studies of other existing devices have shown before there is a massive change in the kinematic behaviour of the muscular abilities by using these tools for a better soft tissue balance. The DLB system is another option by showing 3 different measurement results (tension, distance and joint angle) to adapt the implantation procedure to the individual situation of the patient.
Application-Specific Learning Curve in Computer-Assisted Total Knee Arthroplasty
Authors: Dai Yifei , Angibaud Laurent , Bras Guillaume , Hamad Cyril , Morrison Jefferson Craig
Published: September 2020

This study employed an advanced method (CUSUM) to analyze the learning curve regarding surgical efficiency (time) using two CAOS applications, which were designed to address user needs with different levels of comprehensiveness in term of offered guidance and instrumentation requirements. Two group of surgeons, each used either CAOS applications were included in the study. The first 50 CAOS TKA cases from each surgeon were analyzed to identify the learning curve. The duration of learning, as well as the impact of learning based on surgical time, were assessed with regard to the specific CAOS application and surgeon’s previous CAOS experience level. The data demonstrated differences in term of pattern of adoption during learning process between the two CAOS applications. However, the learning process was not sensitive to surgeon’s experience level.
Alternative Anatomical Landmarks for Anterior Pelvic Plane Determination
Authors: Guezou-Philippe Aziliz , Dardenne Guillaume , Salhi Asma , Burdin Valérie , Lefevre Christian , Stindel Eric
Published: September 2020

The anterior pelvic plane (APP) defined by both anterior superior iliac spines (ASIS) and the pubic symphysis (PS), is used as reference for cup orientation during total hip arthroplasty (THA). However, acquiring the PS and the contralateral ASIS during the intervention with the patient in lateral decubitus position, can be challenging due to the medical devices and the patient abdominal apron. The goal of this study is to find more easily accessible anatomical landmarks, useful for the APP acquisition. Thus we propose to study the variability of the pelvis anatomy in order to identify which landmarks vary with the APP. We built a statistical shape model (SSM) of the pelvis and studied the variability of APP orientation when deforming the SSM along its variation modes. We computed the APP inclination for each deformation and modeled linear relations between the APP inclination and the deformation along the variation modes. We found that the variability in APP inclination is mainly due to 3 variation modes that deform the iliac crest (IC), the posterior superior and anterior inferior iliac spines (PSIS, AIIS). Acquiring those three anatomical landmarks (IC, PSIS and AIIS) with the ipsilateral ASIS, could be a solution to determine more easily the APP for THA in lateral decubitus.
Soft Skills for Hard Hats; a Development Program for an On-Line, Multi-Lingual, Training Program for Construction Supervisors
Authors: Benhart Bradley , Austin Stephen , Bogdanovic Amela , Campbell Janet , Reid Andy
Published: September 2020

This collaborative paper highlights the Soft Skills for Hard Hats project that is a result of a successful bid to the 2016 Call for Erasmus+KA2 – Cooperation for Innovation and Exchange of Good Practices - Strategic Partnerships for Vocational Education and Training funding grant. This project consists of partners from Germany, Spain, Netherlands, Slovenia, Italy, United State of America, and the United Kingdom. Soft skills in construction supervisors has been a growing concern in the European Union. Soft Skills for Hard Hats (SSHH) was in response to that void by creating online, semi-immersive interactive scenarios aimed at first level construction supervisors to help develop soft skills. The focus is on four different soft skills: teamwork, communication, leadership and problem solving. The units are web based vignettes of difficult situations site supervisors are tasked to solve. As the situations evolve, there are pauses for the participants to make management choices. There are multiple paths to solve each situation. Upon completion, participants are provided feedback on how they handled each scenario with short and long term affects. Each unit enables participants to undertake an individualized learning experience based on the choices they make. This paper highlights the concept, framework, scenario outcome maps, examples, assessment, lessons learned and links to the on-line program.
Secure Knee Prosthesis – Processing of Encrypted Data and User Authentication
Authors: Elmoadine Anass , Pistono Maxime , Bellafqira Reda , Coatrieux Gouenou
Published: September 2020

Today, Implemented Medical Devices (IMDs) are key elements of the healthcare system being more and more complex with connectivity facilities. Participating to data collecting, they contribute to improve patient follow-up as well as medical practices. However, with such a connectivity security threats are significant and can be the cause of decision errors, patient privacy concerns and so on. This is why, international and national regulations make mandatory to consider security when developing new IMDs. In the context of resource constrained connected Knee Prosthesis (KP), we present: 1) a solution to securely process data emitted by KP on untrusted Human Machine Interface (HMI) and implementation times; 2) an authentication protocol for installing trust between the different entities involved in the process.
Demographic Challenges Ahead for Construction Education
Authors: Farrow C. Ben
Published: September 2020

The construction economy is strong, and many construction management programs are experiencing record attendance. However, the coming decline within the U.S. in the number of college students (15% decline beginning in 2026) looms large. This exploratory research project seeks to illuminate the potential impact of this demographic shift in five states where a diversity of construction management and geography exists: Alabama, Colorado, Illinois, Texas, and Washington. Results indicate substantial drops in enrollment for schools in Alabama and Illinois and illuminate that almost all regional universities will suffer as a result of the anticipated demographic shifts. Construction management programs should prepare for the coming shifts and increased competition for students. Options include additional emphasis on growing demographic sectors, an additional focus on gender diversity, and shifts in instructional approaches.
Expanded Clay Applications in Internal Curing of Concrete
Authors: Akhnoukh Amin , Massarra Carol
Published: September 2020

Internal curing is used to reduce shrinkage and early age cracking of poured concrete. The internal curing process depends on providing internal moisture to hardening concrete using prewetted light weight aggregates, as expanded slates and shales. The main objective of this research is to produce internally cured light-weight concrete mixes to be used in bridge deck construction. Light-weight mixes are developed by incorporating different percentages of pre-wetted expanded clays in partial replacement of mix coarse aggregates. Expanded clays will internally provide the concrete with adequate moisture to account for water evaporating during concrete hardening. Produced concrete mixes are characterized by light weight, comparable compressive strength, and reduced shrinkage and early-age cracking. Produced lightweight mixes showed comparable strength with minimized shrinkage, which will positively impact the durability of concrete
Effects of Virtual Reality on Student Learning in Materials and Methods Course
Authors: Lucas Jason , Gajjar Dhaval
Published: September 2020

Virtual Reality (VR) offers a method of active and interactive learning. In this research, a VR-based simulated environment is used to help students gain an understanding in the sequencing of construction activities within an undergraduate materials and methods course. The VR simulation was developed to augment traditional classroom learning methods. The sequencing simulation allows students to freely navigate through the simulation and walk through the steps of the construction for a small wood frame structure. The simulation was developed for both immersive and non-immersive desktop-based simulations. During early studies, it was found that students were receptive of the technology and perceived a benefit in understanding spatial qualities as well as components of assembly but actual effects of learning were not identified. The current study explores the actual effects of student learning when incorporating simulation into the coursework. This paper discusses the comparison of students learning from a control group where the simulation was not used to the learning of a group who utilized the desktop-based simulation in addition to traditional classroom methods.
Post Operative Analysis of a Novel Application of Surgical Navigation
Authors: Roberts Benjamin , Theodore Willy
Published: September 2020

A cohort of 84 patients underwent Total Knee Replacement surgery using Patient Specific Instrumentation fitted with an optical tracker that was monitored by a Computer Assisted Surgery system. The CAS system was low cost with small footprint in the operating theatre. The hip centre was collected and four other landmarks were recorded as rotational measures. The CAS system then reported the deviation in PSI placement against the targeted PSI placement, the surgeon then made a judgement whether to replace the guide. Post-operative analysis was done to determine the achieved alignment of the component and compared to the targeted alignment. From 45 results available for analysis the study found that the mean of rotational measures over the femur and tibia were found to be within ±30 of the targeted alignment, except for femur sagittal alignment. When a single outlier was removed from the femur sagittal alignment measures, the mean fell below ±30 of the targeted alignment. Distal femoral condyle resection measures fell below a mean of 1mm and posterior femoral condyle measures fell below a mean of 2mm. Lateral proximal tibial resection fell below a mean of 2.5mm as did medial proximal tibial resection when two outliers were removed. This shows that a CAS system incorporating the low cost, quicker time, and smaller footprint benefits of PSI with the accuracy of traditional navigation may be a feasible device.
A Beamforming Method Based on Polarization Matching
Authors: Yang Xiaohui , Gu Jie , Jiang Jingfei , Li Yunhao
Published: September 2020

By analyzing the polarization-sensitive array model and combining the polarization information of different elements with space-time processing, a beamforming method based on polarization matching is proposed, which realizes the high-performance beamforming of the polarization-sensitive antenna array. The simulation performance comparison with traditional spatial beamforming confirms the high direction finding accuracy and high signal-to-noise ratio robustness of this algorithm.
Industrial Temporal Logic Specifications for Falsification of Cyber-Physical Systems
Authors: Lidén Eddeland Johan , Donzé Alexandre , Miremadi Sajed , Åkesson Knut
Published: September 2020

In this benchmark proposal, we present a set of large specifications stated in Signal Temporal Logic (STL) intended for use in falsification of Cyber-Physical Systems. The main purpose of the benchmark is for tools that monitor STL specifications to be able to test their performance on complex specifications that have structure similar to industrial specifications. The benchmark itself is a Git repository which will therefore be updated over time, and new specifications can be added. At the time of submission, the repository contains a total of seven Simulink requirement models, resulting in 17 generated STL specifications.