Virtual graphic representation of construction equipment for developing a 3D earthwork BIM

BIM provides a visualization of the construction design that allows a construction manager to review the construction process and the information that is associated with the progress. BIM is usually applied to modeling struc­tural objects with parametric geometry where the sequence of process can be predefined. However, BIM technology can also be applied to objects with irregular shape where parametric modeling is not possible such as earthwork topography based on TIN (Triangular Irregular Network).The objective of this research is to develop a 3D earthwork BIM method­ology and provide a graphic simulation that is capable of assisting construction equipment operators during excavation work. The 3D earthwork BIM presents a modeling technique that involves integrating hardware and software technolo­gies. This combination of technologies is used to represent the actual excavator configuration in a 3D virtual environ­ment. When it is applied to actual excavation work, it was proved that the 3D earthwork BIM could synchronize the virtual excavator configuration with the actual excavator configuration during excavation work in real time

Prototyping a remotely-controlled machine for concrete surface grinding operations

The surface of concrete pavement needs to be flattened for the smoothness and comfortability of highways. Surface grinding can provide flatness in the hardened concrete surface, and improve adhesion between the existing con­crete surface and the subsequent layer. The surface grinding process, however, is executed under hazardous work condi­tions and the outcome is affected by a machine operator’s skill. Automation of this process can provide a hazard-free work environment and increase the quality of the ground surface. This paper presents an application of an automated concrete surface grinding machine that an operator can remotely control with computer assistance. A combination of hardware and software technologies was applied to prototype automated functions of the machine. Field tests demon­strated that remote control of concrete surface grinding is feasible and can be utilized as a semi-automated scheme on actual construction sites. First published online: 23 Jun 201

Kidney Transplantation in Sensitized Recipients; A Single Center Experience

A successful transplantation, across a positive crossmatch barrier, is one of the most persistent long-standing problems in the field of kidney transplant medicine. The aim of this study was to describe seven consecutive living renal transplantations in recipients with positive crossmatch for donors or positive for donor specific antibodies (DSAs). A preconditioning regimen including plasmapheresis and intravenous immunoglobulin was delivered three times a week until the crossmatch and/or DSAs became negative. Mycophenolate mofetil and tacrolimus were started two days before the plasmapheresis. The protocol was modified to include administration of anti-CD 20 antibody (rituximab, 375 mg/m2) from the patient number 3 through the patient number 7. All seven patients achieved negative conversion of the crossmatch or DSAs, and the kidney transplantations were successfully performed in all cases. Acute cellular rejection occurred in two patients, which were subclinical and controlled with high dose steroid treatment. Antibody-mediated rejection occurred in one patient, which was easily reversed with plasmapheresis. All recipients attained normal graft function during the 7-24 months of follow up. Our study suggests that sensitized patients can be transplanted successfully with desensitization pretreatment

Possible beneficial association between renin-angiotensin-aldosterone-system blockade usage and graft prognosis in allograft IgA nephropathy: a retrospective cohort study

Background Although immunoglobulin A nephropathy (IgAN) is associated with an increased risk of renal allograft failure, evidences for its treatment, including renin-angiotensin-aldosterone system blockade (RAASB) usage, remain limited. Methods In this bi-center retrospective cohort study, we included patients who were recently diagnosed with IgAN through allograft biopsies. We identified their 6-month antihypertensive medication prescriptions and investigated the association between the medication types, albuminuria changes, and risk of 5-year death-censored-graft-failure (DCGF). The mixed effect model and cox regression analysis were used. Results A total of 464 allograft IgAN patients were included: 272, 38, 33, and 121 patients in the no antihypertensive medication, single agent RAASB, single agent beta blocker (BB)/calcium channel blocker (CCB), and combination therapy groups, respectively. High-degree albuminuria after 6 months of allograft IgAN diagnosis was an important prognostic parameter and a partial mediator for the association between the subgroups and 5-year DCGF. The usage of single RAASB was associated with decrement of albuminuria from allograft IgAN diagnosis (P for interaction = 0.03). The single BB/CCB group demonstrated significantly worse prognosis than the single RAASB group (adjusted hazard ratio, 2.76 [1.09–6.98]; P = 0.03). Conclusions In conclusion, RAASB may be beneficial for graft prognosis in early allograft IgAN patients who require single antihypertensive medication therapy, by means of reducing albuminuria. Further investigation of treatment strategy in allograft IgAN is warranted.This study was supported by a grant from the Ministry of Health and Welfare (No. HI15C2632), a grant from the National Research Foundation of Korea (No. 2019R1A2C2011465), and a grant from the Ministry of Science, ICT and Future Planning of Korea (No. 2015M3C9A2054342). The funder played no role in performing the study; the study was performed independently by the authors

Design of Compact Variable Gravity Compensator (CVGC) Based on Cam and Variable Pivot of a Lever Mechanism

In this paper, we propose a new compact variable gravity compensation mechanism (CVGC). The CVGC can be used to generate gravity compensation torque by using the cam and lever mechanism and can also amplify the target gravity compensation torque by varying the pivot point of the lever. The feature of variable gravity compensation is very useful to the mobile platform, which needs to handle unstandardized tasks with a high variation of the workpiece weight. The proposed CVGC has many advantages. Most importantly, it is designed as a compact, independent one-piece structure and is lightweight, meaning it can easily be used as a mobile platform with a simple modification. The CVGC can also have a full range of compensation angle (360 degrees), so it does not restrict any of the original workspaces of the target platform when it is installed. First, the mechanism concept and details are explained. Next, the mechanics of the prototype for force analysis are presented. Based on these mechanics and cam theory, the methodology of the cam profile design is presented. Finally, the performance of variable gravity compensation is verified through experiments that compare the designed and measured gravity compensation torque. The verification test shows adequate performance, as we had hoped, which shows potential for the development of the CVGC.N

Global experimental verification of Docker-based secured mVoIP to protect against eavesdropping and DoS attacks

Abstract The cloud-computing paradigm has been driving the cloud-leveraged refactoring of existing information and communications technology services, including voice over IP (VoIP). In this paper, we design a prototype secure mobile VoIP (mVoIP) service with the open-source Asterisk private branch exchange (PBX) software, using Docker lightweight virtualization for mobile devices with the immutable concept of continuous integration and continuous deployment (CI/CD). In addition, the secure mVoIP service provides protection against eavesdropping and denial-of-service (DoS) attacks, using secure voice coding and real-time migration. We also experimentally verify the quality of the secure voice and the associated communication delay over a distributed global connectivity environment to protect against eavesdropping and real-time migration to mitigate DoS attacks

MODELING OF SPRAY WALL IMPINGEMENT AND FUEL FILM FORMATION UNDER THE GASOLINE DIRECT INJECTION CONDITION

Direct-injection spark-ignition (DISI) engines, which have a better fuel economy than conventional gasoline engines, have been widely introduced in the market. However, in these engines, the rich air-fuel mixtures associated with fuel films during cold starts, caused by spray impingement, produce particulate matter. To predict soot formation, it is important to predict the mixture field precisely; thus, accurate spray and film models are prerequisites for creating a soot model. Previous wall impingement models were well matched with low Weber number collision conditions, such as those of diesel engines, which have relatively high ambient pressures and small Sauter mean diameters. In this study, the outliers of the previous model were observed to decrease as the collision distance increased and when a strong droplet dissipation occurred owing to a high ambient pressure. However, the kinetic energy in DISI engines is considerably larger than the dissipation energy calculated using the Weber number and surface tension; thus, the amount of dissipation energy should be determined within a realistic range. To analyze the two-dimensional (2D) spray-wall impingement phenomenon more accurately, a 2D child droplet generation was considered. Finally, the film and spray behaviors were measured to validate the SNU model. The Mie scattering images of the gasoline spray near the wall were captured to measure the rebound spray radius. Then, a laser-induced fluorescence with a total internal reflection was used to determine the film shape and thickness. Compared with existing models, the SNU model exhibits better agreement with the Mie experimental results without requiring case-dependent changes to the model constant. However, the film simulation part needs improvement in future work.N

Observations on K-Image Expansion of Image-Mixing Augmentation

Image-mixing augmentations (e.g., Mixup and CutMix), which typically involve mix ing two images, have become the de-facto training techniques for image classification. Despite their huge success in image classification, the number of images to be mix ed has not been elucidated in the literature: only the naive K-image expansion has been shown to lead to performance degradation. This study derives a new K-image mixing augmentation based on the stick-breaking process under Dirichlet prior distribution. We demonstrate the superiority of our K-image expansion augmentation over conventional two-image mixing augmentation methods through extensive experiments and analyses: 1) more robust and generalized classifiers; 2) a more desirable loss landscape shape; 3) better adversarial robustness. Moreover, we show that our probabilistic model can measure the sample-wise uncertainty and boost the efficiency for network architecture search by achieving a 7-fold reduction in the search time. Code will be available at https://github.com/yjyoo3312/DCutMix-PyTorch.git