scholarly journals Modeling the shelter site location problem using chance constraints: A case study for Istanbul

2018 ◽  
Vol 270 (1) ◽  
pp. 132-145 ◽  
Author(s):  
Ömer Burak Kınay ◽  
Bahar Yetis Kara ◽  
Francisco Saldanha-da-Gama ◽  
Isabel Correia
Keyword(s):  
Location Problem ◽  
Chance Constraints ◽  
Site Location ◽  
Shelter Site

scholarly journals TUNNEL PORTAL INSTABILITY IN LANDSLIDE AREA AND REMEDIAL SOLUTION: A CASE STUDY

2019 ◽  
Vol 59 (5) ◽  
pp. 435-447 ◽  
Author(s):  
Farhad Farhadi Ayoublou ◽  
Majid Taromi ◽  
Abbas Eftekhari
Keyword(s):  
Geological Structure ◽  
Construction Process ◽  
Site Location ◽  
Landslide Area ◽  
Tunnel Excavation ◽  
Excavation Process ◽  
Geological Formations ◽  
Zagros Region ◽  
Tunnel Portal

The construction of tunnel portals in mountainous or slope areas often involves problems, which are closely related to factors, such as slope topography, geology, geotechnics, construction geometry and the tunnel excavation method. The activation of landslides or the acceleration of these events is one of the main challenges faced in the construction of tunnel portals. In this paper, we address the instability problem in Sabzkuh tunnel portal that has been excavated with a complex geological profile and high seismicity in Iran’s High Zagros region. The complexity and intense heterogeneity in geological formations, land acquisition problems and the lack of appropriate monitoring programs led to the instability of the tunnel portal. The excavation process started without applying appropriate techniques for a ground stabilization. The use of inappropriate tunnel excavation methods for this unstable geological structure resulted in an activation of an old Solaghan fault and several collapses in the tunnel. Crossing the collapsed areas and reinforcing the tunnel portal took about 7 months and imposed heavy costs on the project. This case study deals with the importance of the choice of the site location, ground and underground monitoring, analysing and summarizing the collected data in order to prepare a geological model before and during the construction process.

scholarly journals A Fuzzy Group Decision Making for a Rail-Road Transshipment Yard Micro Locaton Problem

2018 ◽  
Vol 235 ◽  
pp. 00019 ◽  
Author(s):  
Ivan Belošević ◽  
Sanjin Milinković ◽  
Peter Marton ◽  
Slavko Vesković ◽  
Miloš Ivić
Keyword(s):  
Decision Making ◽  
Location Problem ◽  
Fuzzy Numbers ◽  
Group Decision ◽  
Practical Importance ◽  
Multi Criteria Decision Making ◽  
Intermodal Transportation ◽  
Programming Technique ◽  
Fuzzy Group Decision Making

Rail-road transhipment yards serve as interchange points between rail and road providing transhipment of loading units. These yards are of great importance for smooth functioning not only of railways but also of the whole intermodal transportation chains. The problem of choosing location of railway facilities, such as yards and depots, has great practical importance and is widely considered in the literature. In this paper, we present a multi criteria decision making (MCMD) model for selecting the most suitable micro location of a rail-road transhipment yard. The developed MCMD model is based on combining a compromise programming technique with the theory of fuzzy numbers. This approach was chosen to solve the considered location problem due to the specific decision-making environment that reflects in the presence of non-commensurable and conflicting criteria. As a case study we analysed several alternatives for locating rail-road transhipment facilities in the area of the rail freight yard in Vršac. The results confirm validity and usefulness of this approach.

scholarly journals Hybrid Set Covering and Dynamic Modular Covering Location Problem: Application to an Emergency Humanitarian Logistics Problem

2020 ◽  
Vol 10 (20) ◽  
pp. 7110 ◽  
Author(s):  
Roghayyeh Alizadeh ◽  
Tatsushi Nishi
Keyword(s):  
Location Problem ◽  
Set Covering ◽  
Strategic Decisions ◽  
Maximal Covering ◽  
Planning Decisions ◽  
Tactical Decisions ◽  
Covering Model ◽  
Validation Tests ◽  
Capacitated Facilities

This paper presents an extension of the covering location problem as a hybrid covering model that utilizes the set covering and maximal covering location problems. The developed model is a multi-period model that considers strategic and tactical planning decisions. Hybrid covering location problem (HCLP) determines the location of the capacitated facilities by using dynamic set covering location problem as strategic decisions and assigns the constructive units of facilities and allocates the demand points by using dynamic modular capacitated maximal covering location problem as tactical decisions. One of the applications of the proposed model is locating first aid centers in humanitarian logistic services that have been addressed by studying a threat case study in Japan. In addition to validating the developed model, it has been compared to other possible combined problems, and several randomly generated examples have been solved. The results of the case study and model validation tests approve that the main hybrid developed model (HCLP) is capable of providing better coverage percentage compared to conventional covering models and other hybrid variants.

scholarly journals Construction of ropeways in Slovakia in terms of pre-construction design using helicopters (case study)

2019 ◽  
Vol 263 ◽  
pp. 01002
Author(s):  
Andrej Bisták ◽  
Zdenka Hulínová
Keyword(s):  
Construction Industry ◽  
Transport Mechanism ◽  
Simulation Models ◽  
Weather Conditions ◽  
Positive Experience ◽  
Site Location ◽  
Factors Affecting ◽  
Construction Design ◽  
History Of

Ropeways usually provide access to locations inaccessible to other means of transport. Due to this fact, the construction of ropeways is extraordinarily taxing in terms of both, technology and logistics. The site location is often in terrain difficult to access, which often precludes deployment of common construction mechanisms in ropeway construction. In such case, it is advisable to deploy a transport mechanism independent of the terrain – a helicopter. Functioning as “flying cranes“, the helicopters have been used in construction industry in Slovakia for six decades now. Having amassed positive experience, even the “conventional“ construction industry of the time, especially its ropeway transport segment, started to use the benefits of helicopters, with helicopter deployment subsequently gaining ground and becoming the mainstream technological procedure. Ropeway construction can hardly be feasible without them even nowadays. Throughout the history of helicopter deployment in construction industry, a constant search of improving the efficiency of their work has been under way, necessitated by the helicopter’s sensitivitiy to weather conditions and work procedures alike. The paper presents an analysis of the factors affecting helicopter operation together with a proposed methodology of modeling their work in simulation models and the benefits of such approach.

Terminal Location Problem: A Case Study Supporting the Status Quo

1985 ◽  
Vol 36 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Robert F. Love ◽  
William G. Truscott ◽  
John H. Walker
Keyword(s):  
Location Problem ◽  
Status Quo ◽  
The Status

Improving Accessibility and Efficiency of Service Facility through Location-Based Approach: A Case Study at Narvik University College

2014 ◽  
Vol 1039 ◽  
pp. 593-602 ◽  
Author(s):  
Hao Yu ◽  
Wei Deng Solvang ◽  
Jin Guang Yang
Keyword(s):  
Location Problem ◽  
Service Providers ◽  
Optimization Problems ◽  
Location Model ◽  
Service Facility ◽  
Computational Optimization ◽  
Real World Application ◽  
University College ◽  
Overall Performance

Location problem of service facility has never lost its appeal to both academics and practitioners due to the complexity in balancing availability, responsiveness and efficiency. In this paper, a location-based study is performed in order to improve the accessibility of service facility in terms of availability and responsiveness for customers as well as the efficiency for service providers. This study employs two well-known location models for service facility: Maximal covering location model which aims to maximize the coverage of customer demands with limited number of facilities (efficiency) and p-median location model which aims to minimize the overall distance travelled from customs to service facilities (accessibility), and location-based comparison of the two solutions in a case study at the 3rd floor of the main building of Narvik University College (NUC) for improving the overall performance of printing service is conducted so as to illustrates a deep insight of real-world application. The optimal solutions for maximizing the overall performance are obtained under different scenarios, and Lingo software is applied for resolving the computational optimization problems.

Sign in / Sign up

Export Citation Format

Share Document