Simulation-Based Evaluation of Variation in Left-Turn Paths in the Coordinated Intersection Management

Coordinated intersection management (CIM) has gained more attention with the advance of connected and autonomous vehicle technology. The optimization of passing schedules and conflict separation between conflicting vehicles are usually conducted based on the predefined travelling paths through the intersection area in the CIM. In real-world implementation, however, the diversity of turn paths exists due to multiple factors such as various vehicle sizes and automation control algorithms. The aim of this paper is to investigate how the variation in left-turn paths affects the feasibility and viability of optimal passing schedules, as well as the safety and efficiency of intersection operation. To do this, we start with identifying six typical left-turn paths to represent the variation. A scenario-based simulation is first conducted by using each of the paths as the nominal path. The optimal schedules and the corresponding alternative schedules are generated to calculate indicators for nominal performance, average performance, and robustness. The best path is selected in terms of schedule optimality and robustness. With schedules obtained by solving CIM models using the selected path, the left-turning CAVs are assumed to travel along one of the six paths randomly to simulate the path divergence. A surrogate safety measure, PET, is utilized to assess the safety of the intersection under CIM. The theoretical PET with the nominal path and the actual PET with the random path are calculated for each conflict event. Comparisons of two PET sets show the increase in conflict risk and vehicle delay. The conclusion can be drawn that the variation in left-turn paths causes the decline in safety level and travelling efficiency and should be considered in the CIM model to ensure safe and efficient implementation in the intersection.

MENELISIK POTENSI PPN INDUSTRI HASIL TEMBAKAU MELALUI SINERGI DJP-DJBC PADA KEGIATAN JOINT PROGRAM

ABSTRACT: This study aims to identify the business processes of the Tobacco Products Industry for cigarettes as well as to review and evaluate the implementation of the Joint Program conducted by DJP-DJBC. Using a combination of semi-structured and in-depth interviews with participant of Joint Program along with descriptive analysis of implementation data, it produces empirical evidence that synergies between agencies can contribute more to tax revenues. Implications for the Ministry of Finance to maintain and expand the scope of positive synergies between agencies that have an intersection area to escalate nation's prosperity. Keywords: joint program, IHT cigarettes, tax compliance, tax audit, tax invoice ABSTRAK: Penelitian ini bertujuan untuk mengenali proses bisnis Industri Hasil Tembakau (IHT) rokok serta mengulas dan mengevaluasi pelaksanaan Joint Program DJP-DJBC pada industri tersebut. Penelitian ini menggunakan kombinasi wawancara kepada pelaku Joint Program DJP-DJBC beserta analisis deskriptif data implementasi, menghasilkan bukti empiris bahwa sinergi antarinstansi dapat memberikan kontribusi lebih terhadap penerimaan perpajakan. Implikasi bagi Kemenkeu untuk tetap mempertahankan sekaligus memperluas cakupan sinergi positif antarinstansi yang mempunyai irisan dalam ruang lingkup pekerjaan demi terwujudnya kemakmuran bangsa. Kata Kunci: joint program, IHT rokok, kepatuhan pajak, pemeriksaan pajak, faktur pajak

Hegemonic Formation in Post-Javanese Indonesian Society

In society, there are various structured power relations that connect individuals who share certain interests and objectives. In these power relations, hegemony plays a significant role. Hegemony is the most important notion in the Marxist tradition, especially as it is conceptualized by Gramsci. This paper tries to re-read the issue of hegemony in the context of ideological contestation in Javanese society in Indonesia. The problem will be examined based on post-Marxist theory, especially as it relates to the demolition of the strong order of capitalism. Based on the results of the study, it can be concluded that hegemony forms itself in layers. The layers influence each other so that there is one area of hegemonic intersection. In Javanese society these days, there is a “competition,” especially in Yogyakarta, to return, feel, and become more Javanese than others. The implication is that there are parties who feel more Javanese than others. This case in this study is referred to as the post-Javanese society. However, in the intersection area, there are all-powerful puppeteers.

A Priority-Based Autonomous Intersection Management (AIM) Scheme for Connected Automated Vehicles (CAVs)

In this paper, we investigate the intersection traffic management for connected automated vehicles (CAVs). In particular, a decentralized autonomous intersection management scheme that takes into account both the traffic efficiency and scheduling flexibility is proposed, which adopts a novel intersection–vehicle model to check conflicts among CAVs in the entire intersection area. In addition, a priority-based collision-avoidance rule is set to improve the performance of traffic efficiency and shorten the delays of emergency CAVs. Moreover, a multi-objective function is designed to obtain the optimal trajectories of CAVs, which considers ride comfort, velocities of CAVs, fuel consumption, and the constraints of safety, velocity, and acceleration. Simulation results demonstrate that our proposed scheme can achieve good performance in terms of traffic efficiency and shortening the delays of emergency CAVs.

A Pairing Algorithm for Conflict-Free Crossings of Automated Vehicles at Lightless Intersections

This paper studies the planning of conflict-free and efficient crossings of antagonistic vehicles’ movements at lightless intersections. A fully automated infrastructure environment is considered, where all vehicles that enter the intersection area are connected and automated (CAVs), i.e., they are equipped with advanced communication and automation technologies. In such a futuristic environment, traffic lights that regulate the right-of-way of different traffic streams are obsolete because of vehicle communication capabilities. The connectivity is utilized to derive vehicle trajectories such that a safe and efficient crossing of lightless intersections is possible. So far, published studies lack the application to complex intersection layouts. To fill this gap, we introduce a control method for CAV pairing allowing for the safe, collision-free crossing of the intersecting area and optimize traffic conditions, i.e., total delays of the system. Simulation results demonstrate the feasibility and applicability of the presented approach, given that all the technical specifications (e.g., communications, velocity actuators) are present. Finally, we conduct a sensitivity analysis for the algorithm’s main parameters, which provides practical insights for the studied experimental scenarios and other existing algorithms in the literature that tackle this problem.

Study on Automatic Arrangement Algorithm for Tower Cranes with Applying Lifting Limit Axis

Recently construction projects are becoming more high-rise, and for this reason, efficient operation of tower crane is very important. Therefore, we conducted a study on the development of automatic arrangement algorithm for the efficient operation of tower crane. In this study, a new concept, the 'lifting limit axis' concept was applied to develop automatic arrangement (optimal arrangement) algorithm of tower crane. Through this process, the 'three-dimensional figure' was created and the research was carried out considering the weight of the material, the working radius of the tower crane, and the lifting capacity. In this study, we carried out the study in three dimensions to apply the concept of ‘lifting limit axis', which is different from the existing studies conducted in two dimensions. This is not simply a three-dimensional and two-dimensional difference. The reason for this is that the lifting work can be considered by applying the change in the lifting capacity according to the working radius of the tower crane in three dimensions. Therefore, it is a concept that enables highly efficient and stable lifting work. In this study, we developed an algorithm by applying this concept of 'lifting limit axis', which is divided into four steps. The first step is information input, the second step is identifying the intersection area where the tower crane can be arranged, the third step is to arrange the 'three-dimensional figure' and the last step is to select the minimum-cost simulation out of a number of simulation. This algorithm provides the basic guidelines for tower crane arrangement through the above process. In this study, we applied the new concept of 'lifting limit axis’. Therefore, continuous follow-up research is essential, and it is expected that this will lead to an efficient lifting plan of tower crane.

A Bracket-Stiffened Two-Planar Overlapped Tubular KT-Joint for Offshore Jack-Up Fatigue Analysis

There have been a large number of research programs dedicated to the investigation of stress concentration factor and its parametric design formulae for a variety of uniplanar and multiplanar tubular joints. However, for the multiplanar overlapped tubular joints, the related reports are very limited due to the fact that the combining effect between multiplanarity and brace overlapping is quite complex. In this paper, a novel bracket-stiffened two-planar overlapped tubular KT-joint is proposed by adding two brackets between the upper diagonal and horizontal braces to alleviate the stress concentration at the brace-to-chord intersection area. As compared with the original KT-joint and KT-joint of larger brace gap, stress concentration reduction and fatigue strength enhancement at the most critical point of the proposed KT-joint are significant under both axial and in-plane bending (IPB) loads. The superiority of the proposed KT-joint is further tested with a simplified fatigue life assessment of offshore jack-up in field transit condition, when the KT-joint corresponding to the upper guide level is most critical and fatigue-sensitive. The obtained results with conservative assumptions may serve as guides or references in civil and offshore engineering practices.

A Novel Ship-Ship Distance Model in Restricted Channel via Gaussian-TRR Identification

Very large ships are crucial cargo ships that are relatively difficult to manoeuvre, and ship-ship distance is a vital manoeuvring parameter in restricted channel. To ensure ship safety and improve scheduling efficiency, this study established a ship-ship distance model in restricted channel by ship manoeuvring motion simulation, collision detection, and identification modelling. Firstly, the ship manoeuvring model calculated the forces and moments of ship-ship interaction and ship-bank interaction. Then, the collision detection was applied to calculate the intersection area of ship collision. Secondly, the discrete numerical simulation approach was employed with varying speed and distance, and the intersection area was counted. Finally, the 3D Gaussian models of encountering and overtaking were identified by the trust-region-reflective (TRR) algorithm, and ship-ship distance and prohibited zone were proposed. The results show that the minimum ship-ship distance for encountering and overtaking is 1.50 and 2.4 ship beam, respectively, which is consistent with Japan’s standard. The numerical results revealed that the prohibited zone is an elliptical shape. The ship-ship distance and prohibited zone serve as ship safety domain for collision avoidance during harbor approaching.

Novel Roadside Unit Positioning Framework in the Context of the Vehicle-to-Infrastructure Communication System Based on AHP — Entropy for Weighting and Borda — VIKOR for Uniform Ranking

The positioning of roadside units (RSUs) in a vehicle-to-infrastructure (V2I) communication system may have an impact on network performance. Optimal RSU positioning is required to reduce cost and maintain the quality of service. However, RSU positioning is considered a difficult task because numerous criteria, such as the cost of RSUs, the intersection area and communication strength, affect the positioning process and must be considered. Furthermore, the conflict and trade-off amongst these criteria and the significance of each criterion are reflected on the RSU positioning process. Thus, this work proposes a new RSU positioning framework based on multicriteria decision-making (MCDM) in the context of the V2I communication system. Three stages are completed for this purpose. First, a real-time V2I hardware is developed to collect data. The developed hardware consists of multiple mobile nodes (i.e., cars with sending–receiving hardware devices) and physical RSUs. The RSUs and the devices in the cars are connected via the nRF24L01[Formula: see text]PA/LNA transceiver module with Arduino Uno. Second, seven testing scenarios are identified toward acquiring the required data upon the connection of the V2I devices. Moreover, three evaluation attributes (i.e., number of packet losses [PKL], cost and ratio of intersection area [RIA]) are used to evaluate each scenario. A decision matrix is constructed on the basis of the crossover between ‘RSU positioning scenarios’ and ‘multi-evaluation attributes (i.e., PKL, cost and RIA)’. Third, the RSU positioning scenarios are ranked using MCDM techniques, such as the integrated analytic hierarchy process (AHP), entropy and group Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR). Furthermore, the Borda voting approach is used to aggregate multiple individual rankings into a uniform and final rank. Results indicate the following: (1) integrating AHP, entropy and VIKOR is effective for solving RSU positioning problems; (2) the VIKOR ranking results for individuals vary; (3) the rank of scenarios obtained from the group-VIKOR-based Borda voting context shows that the second scenario, which consists of four RSUs distributed along the street with a maximum distance of 200[Formula: see text]m between them and 2-m high antennas, is the best in terms of optimally placing the RSUs; and (4) significant differences are observed amongst the scores of the groups, indicating that the ranking results are valid.