Effect Of Time Reduction Research Articles

Feature-consistent coplane-pair correspondence- and fusion-based point cloud registration

It is an important and challenging task to register two point clouds, and the estimated registration solution can be applied in 3D vision. In this paper, an outlier removal method is first proposed to delete redundant coplane-pair correspondences for constructing three feature-consistent coplane-pair correspondence subsets. Next, Rodrigues’ formula and a scoring-based method are adopted to solve the representative registration solution of each correspondence subset. Then, a robust fusion method is proposed to fuse the three representative solutions as the final registration solution. Based on typical testing datasets, comprehensive experimental results demonstrated that with good registration accuracy, our registration algorithm achieves significant execution time reduction effect when compared with the state-of-the-art methods.

An optimization model of on-demand mobility services with spatial heterogeneity in travel demand

We propose an optimization model that predicts the required fleet size of on-demand mobility (ODM) services at various service levels for a range of demand patterns. Both customer waiting time and spatial heterogeneity in demand are considered when formulating the flow conservation equation for the system’s steady state. The demand–supply imbalance problem is solved through vehicle relocation. Vehicle relocation is reformulated into a simple linear programming problem, and the objective function is set to minimize the number of relocation vehicles. Furthermore, indicators were defined to more effectively explain the effects of spatial heterogeneity of travel demand on the required fleet size. The analysis results show that even among regions with the same average demand rate, the required fleet size may vary depending on the spatial demand pattern of origins and destinations. The higher the ratio of long-distance travel and the greater the need for vehicle relocation, the larger the fleet size required. Furthermore, the user travel time reduction effect is maximized at the minimum fleet size and then steadily decreases as fleet size increases. Cost minimization requires more vehicles than fleet size minimization. Cost minimization may be an advantageous goal for operation of an ODM service as a driverless vehicle service. The simultaneous consideration of both fleet size minimization and cost minimization provides a required fleet size range. Although the proposed model is simple and includes approximations, it helps provide insight into ODM service design and investment decision-making. Thus, the proposed model can be used by governments or agencies to design policy or operationally optimized services. Moreover, the model can serve as the basis for the practical implementation of planned services.

Hierarchical Single-Objective Model Predictive Control With Reduced Computational Burden in Cascaded H-Bridge Converter Based on 3-Level Flying Capacitor Unit Cell

This paper presents a control algorithm to reduce the computational burden of model predictive control in a grid-connected single-phase N-cell cascaded flying capacitor H-bridge (CFCHB) multilevel converter of a solid-state transformer. The proposed control algorithm is a finite-control-set model predictive control (FCS-MPC) that is based on a hierarchical structure controlling the grid current, DC-link voltage, and flying capacitor voltage, using each cost function through three layers. Unlike the conventional multi objective cost function that evaluates and compares all candidates to determine the optimal state, the proposed method uses a single-objective cost function by separating the control variables to determine the optimal state through calculation without comparison. Therefore, the amount of computation is significantly reduced compared with that of the conventional method, and the execution time is shortened. Thus, the sampling period can be shortened and the switching frequency can be increased. Further, it can lead to using a smaller inductor to produce a high-quality grid current, which can help reduce the system size and cost. The execution time is not large, even if the voltage level increases and the effect of time reduction is large compared to the existing method, because the computational burden of the proposed method is linearly proportional to the number of cells. The voltage level expansion is easy and suitable for digital system implementation, and the control performance is not affected. The effectiveness of the proposed method is verified through the simulation of a single-phase 250 kW 9-cell CFCHB multilevel converter using PSIM and an experiment with a single-phase 2 kW 3-cell CFCHB multilevel converter at the laboratory scale.

Development and evaluation of smartphone usage management system for preventing problematic smartphone use.

ObjectiveThe increased use of smartphones has led to several problems, including excessive smartphone use and the decreased self-ability to control smartphone use. To prevent these problems, the MindsCare app was developed as a method of self-management and intervention based on an evaluation of smartphone usage. We designed the MindsCare app to manage smartphone usage and prevent problematic smartphone use by providing personalized interventions.MethodsWe recruited 342 Korean participants over the age of 20 and asked them to use MindsCare for 13 weeks. Subsequently, we evaluated the changes in average smartphone usage time and the usability of the app. We designed a usability evaluation questionnaire based on the Technology Acceptance Model and conducted factor and reliability analyses on the participants’ responses. In the eighth week of the study, participants responded to a survey on the usability of the app. We ultimately collected data from 190 participants.ResultsThe average score for the usability of the system was 3.61 on a five-point Likert scale, and approximately 58% of the participants responded positively to the evaluation items. In addition, our analysis of MindsCare data revealed a significant reduction in average smartphone use time in the eighth week compared to the baseline (t = 3.47, p = 0.001). Structural equation model analysis revealed that effort expectancy and performance expectancy had a positive relation with behavior intention for the app.ConclusionsThrough this study, we confirmed the MindsCare app's smartphone usage time reduction effect and proved its good usability. As a result, MindsCare may contribute to achieving users’ goals of reducing problematic smartphone use.

A biobased reactive accelerant and diluent for solvent-free drying oils

Drying oils are unsaturated plant oils, widely used in paints and varnishes. The inclusion of solvent thinners and metal catalyst accelerators in drying oil formulations may be problematic from an environmental perspective. We report on the development of a biobased alternative that can act as both a reactive accelerant and a viscosity modifier for solvent-free drying oil systems. The ozonolysis of canola oil and linseed fatty acid methyl esters (FAME) produced compounds that were shown to be effective in directly adding to conjugated carbon-carbon double bonds (-CH=CH-) resulting in faster polymerization. For tung oil, substitution with 25 wt.% of ozonized linseed FAME reduced the drying time by 70% and the viscosity by 60%, while the glass transition temperature approached that of a pure linseed oil film. The drying time reduction effect was found to be strongly dependent on the concentration of ozonized lipids but not greatly influenced by the ozonolysis time. For tung oil, a conjugated drying oil, incorporation of up to 65 wt% ozonized lipids was possible, resulting in dried films within less than 1 h at 60 °C and a 90% viscosity reduction while maintaining up to 100% biorenewable content and air-induced polymerization.

Analysis of reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo

Objective:Comparative analysis of the reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike（D-H） or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo（PC-BPPV） and PC-BPPV without above evoked nystagmus. Method:Retrospective analysis of 210 patients diagnosed with unilateral PC-BPPV by G-Force BPPV CRP system was made. Among them, 18 patients exhibited positive nystagmus only when the non-affected side was stimulated by D-H test（Group A）, 30 was evoked only when stimulated by Roll-test（Group B）, 26 was evoked when stimulated by both Roll-test and the non-affected side D-H test（Group C）, 136 without nystagmus in the above positions（Group D）. All the patients were diagnosed by G-Force BPPV and were treated through simulative Epley or Semont CRP. Compare the reduction effect among the groups. Result:At the first time ,the reduction effect of nystagmus in Group D was superior to those in Group A and Group C（P<0.05）. There was no difference between Group D and Group B（P>0.05）. The difference between Group A and Group C was also non-significant（P>0.05）. The average CRP times of the four groups（CRP until nystagmus disappeared or no longer alleviated） were 1.44±0.63（Group A）, 1.46±0.65（Group B）, 1.52±0.87（Group C） and 1.48±0.73（Group D）respectively. There were no statistic difference between four groups（P>0.05）. The differences of final reduction effect between groups were the same as those at the first time. Conclusion:The first time reduction effect was less effective when nystagmus evoked the non-affect side during D-H test in unilateral PC-BPPV, while it might be irrelevant to the nystagmus evoked only in Roll-test. Although the times of CRP were similar among the groups, the final reduction effect of groups with nystagmus evoked the non-affect side during D-H was poorer.

Faster Acquisition for Dopamine Transporter Imaging Using Swiftscan Step and Shoot Continuous SPECT Without Impairing Visual and Semiquantitative Analysis.

Aim: Dopamine transporter (DAT) imaging with [123I] FP-CIT (DaTSCAN) is an established diagnostic tool in parkinsonism and dementia. Using a low energy high resolution and sensitivity (LEHRS) collimator and step and shoot continuous scanning mode, Swiftscan single photon emission computed tomography (SPECT) (GE Healthcare) enhances sensitivity and enables time or dose reduction. In this phantom and clinical study, we aim to validate a 25% reduction of the acquisition time using Swiftscan and its lack of effect on visual or quantitative analysis.Methods: Anthropomorphic striatal phantom with fillable striata was used. SPECT data from 30 normals (12 men, 18 women; age range, 39–91 years; mean, 71 years ± 11) and 30 patients with Parkinson disease or other neurodegenerative disease with extra-pyramidal syndrome (16 men, 14 women; age range, 43–84 years; mean, 69 years ± 10) were also included. Both phantom and clinical data were acquired using Swiftscan and reconstructed with full-time and 25%-time reduction. Striatal binding ratios (SBRs) were calculated using DaTQUANT software.Results: Both in phantom experiments and in clinical cases, visual analysis remained stable and SBRs were not significantly different whether using Swiftscan or Swiftscan with 25%-time reduction (p < 0.001). There was an excellent inter-rater agreement and no effect of time reduction on diagnosis or on image quality.Conclusion: Using Swiftscan step and shoot continuous SPECT mode, 25%-time reduction can be applied to DaTSCAN acquisition protocols, without impairing visual or quantitative analysis.

A Study on a Simple Algorithm for Parallel Computation of a Grid-Based One-Dimensional Distributed Rainfall-Runoff Model

This paper presents an algorithm that can efficiently simulate a grid-based one-dimensional distributed rainfall-runoff model by performing parallel computations using flow accumulation values for individual grid cells, which are calculated through an eight flow direction method. This parallel computation algorithm uses information about flow accumulation to automatically find parallel computation target grid cells within the overall area and perform parallel computation on the grid by unit. The Microsoft.NET Parallel class was used to apply and evaluate the parallel computation algorithm independently on two machines. The results showed that the time reduction effect of parallel computation differed for each target domain, because flow accumulation values varied depending on the domain. Parallel computation reduced computation time by around 40% to 78% in virtual domains and around 63% in the real domain compared to sequential computation. The results of this study can be utilized to reduce the computation time of distributed models.

Analysis of energy consumption of room air conditioners: An approach using individual operation data from field measurements

Room air conditioners (RACs) are heating/cooling appliances used widely in residential buildings. RAC seasonal or annual performance is strongly influenced by the user’s operation schedule and by mechanical efficiency. In this paper, we address the energy consumption of RACs under different heat-load conditions and schedules. Individual operations were extracted from a series of energy consumption data for 87 RAC units. Individual operation data were divided into two groups, mild- and severe-load conditions, whose outdoor temperatures differed by 5°C. Mild-load conditions tended to result in shorter individual operation durations than did severe-load conditions, suggesting a difference in user behavior. When individual operation durations were reduced by 20%, average energy reductions of 40% were observed. Part of this reduction resulted from duration reduction; the rest came from changes in RAC physical efficiency, which depends on outdoor temperature and heating/cooling load. The time-reduction effect exceeded the physical-efficiency effect when individual operation durations were shortened by >20% during heating, or by >26% during cooling.

TIME REDUCTION EFFECT OF THE ENHANCED TACT METHOD FOR HIGH-RISE RESIDENTIAL BUILDINGS

The finish work on high-rise residential buildings is performed simultaneously with mechanical and electrical construction work, which results in frequent work interference and delay. This significantly hinders efficient schedule management. Critical Path Method (CPM) is inefficient when applied to high-rise residential building projects in which work is repeatedly carried out for each floor. Line-of-Balance (LOB) is widely used for its effectiveness in managing repetitive work. LOB was developed into TACT and eTACT (enhanced-TACT) to combine heterogeneous works con­tinuously. In particular, the eTACT schedule management method has an advantage in that it is capable of systemati­cally connecting detailed construction, mechanical and electrical construction projects using a work planning template. This study evaluates the time reduction effect of the eTACT method for a high-rise residential building. A comparative analysis of data on 102 cases of non-applied projects and 44 cases of projects using the eTACT method over a period of 10 years is presented to verify its effectiveness. The result shows that finish work time was reduced by 25% or about 53 days on average.

Time-based procurement

This study investigates the design of a time-based procurement contract when a supplier possesses private information about intrinsic completion time and may choose to exert time reduction effort. We first derive the optimal (complex) contract for the buyer, and then evaluate the performance of a (simple) fixed-price and fixed-time (FPFT) contract. Our analysis shows that the structure of the optimal time-based contract and the performance of an FPFT contract depend largely on time reduction forms. Specifically, if time reduction follows a multiplicative model, the optimal contract induces the intrinsically slow supplier to reduce time, and offers a fixed payment to the intrinsically fast supplier. This result is opposite to what could occur when time reduction follows an additive model. We also show that, in a specific multiplicative model, the FPFT contract achieves at least eight-ninth of the available surplus for the buyer, whereas the performance of an FPFT contract deteriorates dramatically in an additive model. In response to this underperformance, we then propose an enhanced linear contract, and demonstrate that, using this contract, the buyer loses no more than one-sixteenth of the available surplus. Our results shed light on the important effect of time reduction forms on time-based contract design.

Lot-splitting approach of a hybrid manufacturing system under CONWIP production control: a mathematical model

This paper discusses the advantages of lot splitting in hybrid manufacturing environments where cellular and functional layouts are combined under Constant Work in Process (CONWIP) production control. The proposed model fills a research gap in the related literature by applying lot splitting and pull production simultaneously. A linear CONWIP control mathematical model that minimises the average flow time is developed in case of lot splitting. The developed model has sequence-dependent set-up times. The demand level, coefficient of variation (CV) impact and set-up time reduction effect on CONWIP production control are also investigated. The model is solved using GAMS21.6 optimisation software; the optimal backlog list, the number and size of sublots are reported. The proposed model is compared with lot production under push control in different settings as well as with two different heuristics from the literature. Experimental results indicate that in all settings, the lot splitting is more advantageous than lot production in terms of average flow time. CV has a greater effect than set-up time reduction on average flow time.

Rapid synthesis of octosilicate, a layered alkali silicate, by heterogeneous nucleation at the solid–liquid interface

This paper describes a novel method for rapidly synthesizing the crystalline alkali silicates ilerite and octosilicate by heterogeneous nucleation at a solid–liquid interface. To form the solid–liquid interface in the starting sodium silicate solution, solid balls of different materials and sizes were dispersed in the solution. The ball-containing solutions were subjected to a static hydrothermal reaction. The presence of the balls promoted crystallization, leading to a considerable reduction in the time required to attain chemical equilibrium. The time reduction effect was noticeable when zirconia balls were used, which had a relatively high critical surface tension. The surface area of the balls also greatly affected the crystallization process, and the estimated total number of formed crystals was nearly proportional to the surface area of the balls (i.e., the solid–liquid interfacial area), suggesting that crystallization was promoted by the heterogeneous nucleation on the surface of the balls. The presence/absence of balls can serve to control both nucleation and crystal growth, which may facilitate size control of the products. This method yielded well-grown crystals with a lateral size almost twice that of a product synthesized by conventional synthesis. The use of the solid–liquid interface was useful in both reducing the crystallization time and controlling the size of the crystals.