Vertical Alignments Research Articles

Magnetic-Field-Driven Reconfigurable Microsphere Arrays for Laser Display Pixels.

Reconfigurable microlaser arrays are essential to the construction of display panels where the individual pixel should be highly tunable in resonance mode, optical polarization, and lasing wavelength upon external control signals. Here we demonstrate a facile yet reliable approach to fabrication of organic microlaser pixels, in which the assembly of microsphere arrays on each pixel is controlled according to the near-field magnetostatic confinement. The geometrical configuration of diamagnetic microspheres could be readily modulated with the near-field potential traps by using the external field to alternate the saturation magnetization of the underneath micromagnet. The motion of microspheres can be modulated among several states upon applied field, and the reconfigurable microsphere array is thus achieved with high spatial precision and rapid temporal response. Moreover, both isolated and coupled spheres serve as low-threshold microlasers with tunable optical resonance modes, whereas the switching between the vertical and horizontal alignments of coupled spheres manipulates the polarization of lasing outputs. By repeating the magnetostatic confinement on the same substrate, the full-color laser display pixels with magnetically tunable color expression capability are successfully achieved.

The Congestion Factors of Container Truck Travel from Tanjung Emas Port to the Hinterland Region

Semarang Container Terminal or Terminal Petikemas Semarang (TPKS) at Tanjung Emas Port is one of the container terminals in Indonesia with growing container traffic, recorded in 2020 reached 712.062 TEUs. The interaction of the components of the transportation system between ports, road facilities and container trucks needs to be synergized, for the smooth flow of container traffic and avoiding travel obstacles or road congestion. Container movement congestion is the result of an imbalance between traffic volume and road capacity, especially container trucks, resulting in the level of road service which ultimately results in a decrease in vehicle speed. This research aims to find the clarity about the main factors forming congestion based on the dynamics of environmental change, using an analysis of the variables causing congestion based on the results of a survey in 2013 with 30 samplings of container trucks and 60 samplings of container trucks in 2019 on the road from Tanjung Emas Port, Semarang to the hinterland area around Ungaran, Semarang Regency. The analysis was conducted by using descriptive regression method and model testing with Minitab 18 software. It can be explained that the main factors causing congestion that have an impact on decreasing speed affecting the travel time of container trucks are road geometric such as road gradients, vertical alignments, intersection and activity on shoulder.

Trends and Analysis of Graduate Programs

Due to the influx of students in higher education institutions, this study was designed to generate, process, and analyze students’ information using online data retrieval. The system was crafted using data mining techniques. The PHP scripting language for web development and the V-Model Design were employed during the course of the study. To analyze the data, simple recursive algorithm was used. The procedure solved the base cases that directly recurs with a simpler sub problem and does some extra work to provide the solution to the simpler sub problems. In this study, it combined the records from one table to another to generate results and determine all the registered enrollees in the system. Respondents included new students, old students, and the graduates of the academic institution under survey. The objective is to replace the actual rigorous paper works during every transaction engaged by the students. The system used to generate information on enrolment, vertical alignments, and program trends. The study found out that the system was deemed effective in terms of system, information, and service quality.

Railway Alignment Optimization Considering Lifecycle Costs

The problem of railway alignment optimization is studied, with particular attention given to computing lifecycle costs while considering train speed profile optimization and traffic demand. Recurring expenses, including energy, user, and maintenance costs, are considered in the lifecycle. A novel speed profile optimization method for the energy-efficient operation of trains is developed and incorporated in a simulation model, which considers regenerative braking energy. According to the train motion simulation results, the energy consumption and travel time per round trip are obtained, based on which the recurring costs are computed by taking traffic demand into account. The horizontal and vertical alignments are jointly optimized with the train speed profile based on the computed recurring and initial expenses, which include rolling stock, earthwork, bridge, tunnel, right-of-way, and length-dependent construction costs. A case study and sensitivity analyses are presented to discuss the impacts of traffic demand on the optimized railway alignment. The effectiveness of the speed profile optimization method is demonstrated by comparing its simulated results with those without speed control.

Optimization of metro vertical alignment for minimized construction costs and traction energy: A dynamic programming approach

Vertical alignment significantly affects the construction costs and train traction energy use of a metro system. Existing studies on this subject mostly optimized the vertical alignment while considering train traction energy consumption or construction costs only. There is still a lack of efficient approach for the vertical alignment optimization problem which considers both construction costs and traction energy consumption. To this end, this paper proposes a two-stage optimization program involving both the design of metro vertical alignment and train speed profile, with the objective of minimizing the total costs of construction and train traction energy. An iterative approach is proposed for solving the two-stage program, in which a dynamic programming (DP) algorithm with a backward search method is designed to seek an optimal vertical alignment given an energy-efficient train speed profile. The model and algorithm approach are tested on real-world case studies on the Line 14 of Guangzhou Metro in China. The results show that compared with the existing heuristic algorithms, the DP approach performs better in computation time and solution quality. Moreover, the optimized vertical alignments outperform that designed by experienced designers in terms of total costs of construction and traction energy consumption, with an average savings rate of 6.0%.

The Role of Middle Management and the Mediation of Artifacts in the Process of Organizational Change

The present article proposes a reflection on the skills that organizations and managers need to develop to deal with the processes of change, mediated by artifacts influencing routines. The qualitative descriptive methodology employed was a case study in a plastic extrusion plant, where the change in routine was mediated by several artifacts that played unequivocal roles in the process: as mechanisms for recording information, for communication, for horizontal and vertical alignments, as a means of ensuring the execution of the routine, and as problem-solving facilitators. The results found help to understand how middle management led the change in the organization, acting as a facilitator and articulator of the process, based on the skills of communication, awareness, alignment and proximity, shared vision, and engagement, mediated by various artifacts. These skills favored the creation of a relationship of interdependence and interconnection between multiple agents, and the intelligent use of artifacts, creating autonomy and greater space for spontaneous exchanges. For the organization, it had a positive impact on performance, prompting the reflection that the future of management permeates the manager's capacity for agency to create an environment of interconnection based on communication, respect and mutual trust, where artifacts can play their enabling role.

Accident risk analysis of road geometric components using functional worthiness approach

The geometric design of the road should be based on the road design criteria and requirements contained in the design guidelines. However, the limitations of natural conditions and considerations during the design make the road design not ideal according to the guidelines. Deviations from the guidelines may indicate that the road is not standard and has potential accident risk. This study intends to analyze the risk of accidents from the geometric aspect of the road. The purpose of this study is to find out how the level of accident risk is due to the geometric conditions of the road. The approach used in this analysis is functional worthiness where each road component is compared with field data and design guidelines. The data collection method was carried out by measuring the geometric components of the road, which included horizontal and vertical alignments. The location of data collection was national roads in the Jambi Province area with a total road length of 1.095 km. For analysis purposes, the road data is divided into 82 segments. The analytical method used is multiple regression with various statistical parameters related to these results. The modeling results show that the regression coefficients for each variable horizontal alignment, vertical alignment, and combination of horizontal and vertical alignment are 0.248, 0.349, and 1.170, respectively. While the constant in this regression equation model is 3.366. The greatest value of the accident risk contribution is in the horizontal and vertical alignment variables with a coefficient of 1.170. The results of statistical tests show that the relationship between accident risk and the geometric aspect of the road has a strong linear relationship

Vertical Clearance Assessment of Overpassing Structures on Sag Vertical Curves

The paper investigates areas on sag vertical alignments where overpassing structures impose restrictions on truck drivers’ sight distance. The assessment is performed for the least desired case where the driver’s sightline is equivalent to the defined stopping sight distance (SSD). The overall objective is to define the boundaries where such overpassing structures limit the available sight distances for truck drivers below the required SSD and thus to provide valuable guidance to practitioners. Initially, the authors addressed the SSD calculation on variable grades during the braking process through an earlier approach based on the point mass model and the laws of mechanics. As a second step, truck deceleration rates were determined from the literature. The effect of various design speeds was examined, corresponding to specific ranges of grade values and sag vertical curvature rates. The methodology was based on calculating the difference between the truck driver’s line of sight and the road alignment at fixed locations and associating the defined value with the desired vertical clearance rate (VC). The analysis revealed that critical cases arise for design speed values between 90 km/h and 110 km/h. The examined cases for Vdesign = 100 km/h and Vdesign = 110 km/h revealed more critical concerns since the assessment showed that even a VC value of 4.90 m is not adequate to address SSD provision. Such cases require further attention, especially when the entering downgrade to the sag vertical curve is long and steep.

PERENCANAAN GEOMETRIK JALAN TOL CIBITUNG – CILINCING INTERCHANGE TAMBELANG KABUPATEN BEKASI

The regencies of Bekasi, Karawang, and Purwakarta are experiencing rapid economic growth,because they are the center of the largest industrial area in West Java. This condition causes an increase intraffic on the Jakarta-Cikampek toll road to Jakarta or vice versa so that congestion often occurs. To overcomethese problems, it is necessary to build a toll road that can break down congestion on inner city toll roads, theCibitung - Cilincing toll road is made to reduce congestion on inner city toll roads because freight cars can godirectly to the port without having to go through the inner city toll road. . The purpose of this study is to planthe geometry of the toll road, especially in the access ramp section to and from the toll road. Geometricinterchange planning methodology by following the 2001 AASHTO standard, Procedures for GeometricPlanning for Inter-City Roads no. 038/TBM/1997, Geometric Planning Standards for Urban Roads 1992. Fromthese geometric plans selected 1 ramp located at the Tambelang interchange, the geometric planning analysisincludes vertical alignment, horizontal alignment the bend types used in the design include FC, SCS bends, andfor vertical alignments are concave and convex.

Analysis of Differences in the Levels of TPACK: Unpacking Performance Indicators in the TPACK Levels Rubric

Since the development of the technological pedagogical content knowledge (TPACK) framework, researchers have been developing a variety of instruments to measure the TPACK of pre-service and in-service teachers. The task of developing an efficient, reliable, and valid instrument is difficult. Even validated instruments require guidance for consistent use that preserves the instrument fidelity. The purpose of this study is to provide guidance for using the TPACK Levels Rubric, a validated instrument that was developed on the basis of the model for the progressive levels of TPACK. The authors systematically examined the criteria of the rubric in order to understand the differences in the levels of TPACK for each rubric component, and developed lesson exemplars to create guidelines for educators using this tool in assessing the TPACK levels of teachers. The iterative instrument analysis also led to the revision of the original rubric to establish the horizontal and vertical alignments and the consistency of the rubric, for each level across four components, and for each component across five levels. The construct validity of the revised rubric was confirmed on the basis of a exploratory factor analysis of 175 mathematics lesson plans and videos of taught lessons developed by graduate special education pre-service and in-service elementary school teachers.

A highly orientational architecture formed by covalently bonded graphene to achieve high through-plane thermal conductivity of polymer composites.

Combining the advantages of high thermal conductivities and low graphene contents to fabricate polymer composites for applications in thermal management is still a great challenge due to the high defect degree of exfoliated graphene, the poor orientation of graphene in polymer matrices, and the horrible phonon scattering between graphene/graphene and graphene/polymer interfaces. Herein, mesoplasma chemical vapor deposition (CVD) technology was successfully employed to synthesize vertically aligned graphene nanowalls (GNWs), which are covalently bonded by high-quality CVD graphene nanosheets. The unique architecture leads to an excellent thermal enhancement capacity of the GNWs, and a corresponding composite film with a matrix of polyvinylidene fluoride (PVDF) presented a high through-plane thermal conductivity of 12.8 ± 0.77 W m-1 K-1 at a low filler content of 4.0 wt%, resulting in a thermal conductivity enhancement per 1 wt% graphene loading of 1659, which is far superior to that using conventional graphene structures as thermally conductive pathways. In addition, this composite exhibited an excellent capability in cooling a high-power light-emitting diode (LED) device under real application conditions. Our finding provides a new route to prepare high-performance thermal management materials with low filler loadings via the rational design of the microstructures/interfaces of graphene skeletons.

Impact of Combined Alignments and Different Weather Conditions on Vehicle Rollovers

Combined horizontal and vertical alignments are frequently utilized in mountainous interstates in Wyoming. These challenging terrain conditions, coupled with adverse weather conditions, affect vehicle stability and may lead to hazards. There is a dearth of research on systematically examining the effects of different combined alignments on safety in terms of rollover propensity including their interactions. Researchers resorted to observational methods that inhibited the control of key variables. Instead, vehicle dynamics simulation modeling was employed to investigate the rollover propensity of vehicles navigating curves of varying geometric design and environmental characteristics. Instead of simulating the full range of curve geometries throughout this study, we considered the most critical curves that were identified as areas of concern. A multinomial regression model was then developed to further quantify the impact of several key factors in terms of roll stability. Results show that: 1) tight degrees of curvature and steep downgrades raised the lateral acceleration and, with higher operating speeds, the impact was more critical. 2) Compared to passenger cars and sports utility vehicles (SUVs), the highest lateral acceleration was acting on semi-trailer trucks. Moreover, SUVs and semi-trailer trucks decrease the rollover margins compared to passenger cars by 0.144 and 0.158 respectively. The study provides new insights regarding the impact of various interactions between the factors, particularly when applying brakes. The study provides a safety assessment for curves' speed limits that could assist Wyoming Department of Transportation (WYDOT) in assigning appropriate speed limits. To the best of the authors' knowledge, no previous studies were conducted to investigate these impacts for combined curves. This study is beneficial to transportation agencies in Wyoming and all other locations that are characterized by mountainous terrain since hazardous sections, having combined horizontal and vertical curves, were identified. Also, situations that require additional attention from law enforcement agencies are pinpointed.

Impact of mountainous interstate alignments and truck configurations on rollover propensity

Introduction: Combined horizontal and vertical alignments are frequently utilized in mountainous interstates in Wyoming. The roll stability of trucks on these challenging terrain conditions is of great concern for transportation officials. The impact of curve characteristics combined with truck configurations has not been considered in the literature due to data availability issues related to the weight and Center of Gravity (CG) payload height of trucks. Method: High-fidelity vehicle dynamics simulation modeling is employed to investigate the rollover propensity of trucks navigating curves of varying geometric design and truck characteristics. A multinomial regression model was then developed to further quantify the impact of these key factors and the effect of their interactions on rollover safety margins. Results: It was shown that complying with the assigned speed limits of the curved roadways is not enough to navigate a curve without experiencing a rollover under some circumstances. The CG payload height and the operating speeds have the highest impact on the safety margins of a truck rollover. Steeper downgrades would amplify the impact of the gross weight of a truck. Tighter curves would also raise the impact of the truck configurations. Conclusions: This study assessed the curve speed limits and revealed that the exciting approach to assigning safe speed limits should be modified according to the aforementioned factors. For the first time, findings from this study shed light on the direction and magnitude of the impact of the truck configurations coupled with curve features that contribute to truck rollover safety margins. Practical Applications: This study revealed the impact of truck configurations on the roll stability of trucks and pointed out critical cases that should be treated very cautiously by drivers. This assists transportation agencies in assigning more appropriate speed limits of curved roadways according to truck conditions.

Revealing Pt-seed-induced structural effects to tribological/electrical/thermoelectric modulations in two-dimensional PtSe2 using scanning probe microscopy

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) provide an opportunity to investigate diverse scientific phenomena at an atomic level and have effective technological potential. In recent times, unlike conventional TMDCs, platinum diselenide (PtSe2) has garnered considerable attention owing to its i) fascinating electrical and optical features coupled with mechanical strain and ii) scalable synthesis method. However, its local electrical/tribological/mechanical properties are yet to be examined in detail. In this study, we prepared two different types of PtSe2 layers by controlling the thickness of the Pt-seed film: i) one with horizontal alignments, which are made from ultrathin Pt films and ii) one with vertical and horizontal alignments, which are made from a relatively thick Pt film. Then, the local tribological, mechanical, and electrical properties of PtSe2 were evaluated mainly with scanning probe microscopy (SPM). The local friction study unveiled the marked friction variation depending on the layer directions. An additional study on the local mechanical property indicated that the apparent modulus difference between the two growth directions can lead to dissimilar friction behaviors. Furthermore, local current probing using SPM showed that PtSe2 with both layer directions provides ohmic features to both directions, although the magnitude of conductance along the horizontal direction is ~100 times smaller than that along the vertical one. On the contrary, PtSe2 with only in-plane alignments is configured with multiple horizontal PtSe2 layers, densely stitching themselves together one after another with a very narrow trench region at their boundary. Surprisingly, a local current–voltage spectroscopy analysis showed a small current gap on the bridged trench region, in contrast to the ohmic behavior of the grain interior. This indicates that the local metal-to-semiconductor transition is available, owing to thin PtSe2 layers in the trench regions. The following study at macroscale showed how the overall electrical and thermoelectric properties of PtSe2 can be influenced by local structures triggered by the variation in Pt-seed thickness. The results not only provide a new insight on better understanding the intrinsic features of 2D PtSe2, but also offer important characterization guidance on tailoring their functionalities.

A Tale of Three Official English Textbooks: An Evaluation of Their Horizontal and Vertical Alignments

A Tale of Three Official English Textbooks: An Evaluation of Their Horizontal and Vertical Alignments

Feasibility study of highway alignment design controls for autonomous vehicles

In recent years, the development and testing of autonomous driving technology have become widespread around the world. However, due to differences in perception abilities between autonomous vehicles and human drivers, the current geometric design controls for highway alignments, designed for the human driver, may not be applicable to the autonomous vehicle (AV). Few studies, however, have systematically investigated the design controls for autonomous vehicles, though we face full driving automation in the next few decades. Because the range of modern AV sensors reaches 250 m, with expected further improvements in the near future, there is a need to determine how the sensors’ perception field and perception-reaction time may affect the current road design standards developed for human drivers. This study therefore tested the feasibility of the current design controls for fully-autonomous vehicles by separately computing controls for vertical alignments and combined horizontal and vertical alignments, considering the AV’s perception abilities of perception-reaction time (PRT), sensor height, and upward angle from the horizontal. The required stopping sight distance (SSD) and minimum length of sag and crest vertical curves were derived and compared with those for human drivers. Computations for combined alignments were based on Green Book coordination guidelines: as the minimum length of horizontal curve can be used for alignments adhering to guidelines, preview sight distance (PVSD) was computed for alignments that do not. Results showed that 1) AV-based design controls on vertical curves were more tolerant than those based on human drivers; and 2) the dominating criterion of sag vertical curve design control was comfort for autonomous vehicles, versus required SSD for human drivers.

Assessment of Young Drivers’ Driving Behaviour and Driving Speed along Horizontal and Vertical Alignments

Young drivers are more likely to experience car crashes as they tend to have risky driving behaviours. This study aims to assess young drivers’ driving behaviour and driving speed along the horizontal and vertical alignments of roads. The 20 young drivers who participated in this study were asked to complete a self-reported assessment (Driver Behaviour Questionnaire) and then invited for an on-road driving assessment during daytime and night-time, along horizontal and vertical road alignments at a selected route in Skudai, Johor. The results from the Driver Behaviour Questionnaire revealed that distractions during driving was the most frequently reported behaviour that caused car crashes amongst young drivers, followed by error and violation. Speed profile was found to be higher during daytime when compared to night-time. A significant difference in speed between male and female drivers was noted at horizontal curves during daytime and vertical curves during night-time. The study concluded that such aberrant driving behaviours would have an impact on the driving performance, particularly on horizontal and vertical curves.

A preliminary inquiry on the association between pre-admission assessments and academic performance of first year dental technology students’ within a South African university of technology

The use of selection, diagnostic, proficiency, placement, admission, manual dexterity and aptitude tests can reportedly predict students’ academic success. Predictive admission procedures help to reduce dropout rates, improve academic performance, increase success rates, and selectively exclude applicants who are unlikely to be successful in the course. There is an absence of research, however, in this area of work in Dental Technology. To examine the association between pre-admission assessments and Dental Technology students’ academic performance in a South African University of Technology. A quantitative and cross-sectional study design was used. The target populations were the 2018 and 2019 first-year Dental Technology students. Retrospective data extracted from academic records and programme files were statistically analysed to measure the correlations against students’academic performance. Despite there being no significant differences between pre-admission tests and students’ academic performance, there were significant positive correlations between first year university subjects. There are indications of horizontal coherence between the discipline-specific subjects in the first-year Dental Technology curriculum. Examining the association between pre-admission tests and students’ academic results through to graduation, together with the horizontal and vertical alignments of all subjects in the undergraduate Dental Technology curriculum, can facilitate the learning pathways for students to succeed academically at universities.

Effects of Soil-Foundation-Interaction on the Seismic Response of a Cooling Tower by 3D-FEM Analysis

This paper reports on the results of soil-foundation numerical modelling and the seismic response of a cooling tower founded on piles of a petrochemical facility located in the city of Augusta (Sicily, Italy). The city was affected in the past by some destructive earthquakes (1693, 1848, and 1990) that damaged a large territory of Southeastern Sicily, which was characterized by a very high seismic hazard. With this aim, the paper reports the FEM modelling of the seismic behaviour of the coupled soil-structure system. To determine the soil profile and the geotechnical characteristics, laboratory and in situ investigations were carried out in the studied area. The seismic event occurred in January 1693 and has been chosen as a scenario earthquake. Moreover, a parametric study with different input motions has also been carried out. A Mohr-Coulomb model has been adopted for the soil, and structural elements have been simulated by means of an elastic constitutive model. Two different vertical alignments have been analysed, considering both the free-field condition and the soil-structure interaction. The dynamic response has been investigated in terms of accelerations, response spectra, and amplification functions. The results have also been compared with those provided by Italian technical regulations. Finally, the seismic response of the coupled soil-structure system has been further examined in terms of peak bending moments along the pile foundation, emphasizing the possibility of a kinematic interaction on piles induced by the seismic action.

The techniques and challenges of GPS surveying for vertical alignments in high-rise buildings

PurposeVertical alignment in high-rise building is a very important aspect. The architects are nowadays interested in improvising untypical complicated morphology in building designs which increase the difficulty in surveying for vertical alignments. Although the GNSS survey techniques are widely applied in constructions, there is a lack of data sources to explicitly expose their applicability in high-rise buildings and the challenges to be considered. This study has been oriented to find out the best suitable GPS survey technique for the vertical alignment in high-rise buildings and the practical challenges to be considered.Design/methodology/approachThe findings have been attained by analyzing the reliable data gained through experts' comments through structured questionnaire survey, case studies and experiments on different GPS survey techniques.FindingsThe findings express that the GPS techniques can be used for vertical alignments in high-rise buildings except for direct setting out for which only RTK GPS can be used. There are some practical challenges to be considered in such GPS applications.Research limitations/implicationsThe findings encourage the research community to further focus on the GNSS survey applications in the constructions of high-rise buildings.Practical implicationsThe research expresses applicability of easier and less time-consumed modern GNSS survey techniques instead of traditional survey methods for expediting building constructions.Social implicationsThe knowledge on such modern rapid survey techniques with accuracy, efficiency and reliability highly affects the process of infrastructure development.Originality/valueThe research presents a useful new knowledge on applying GNSS survey techniques for precise survey requirements in the construction industry and exposes the gateways for further researches and development.