Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

A method to improve the prediction of ship resistance in shallow water

The traditional approach of extrapolating the experimentally measured model resistance of a ship to full scale is based on the Froude assumption or the form factor assumption, where the viscous part and wave-making part of the resistance are dealt with in deep water. In shallow water, however, the water-depth dependency of flat-plate/ship frictional resistance as well as form- and wave effects are expected. It is found in this research that all of these three properties are deviating more or less clearly from the traditional understanding from certain water depths. In this dissertation, a correct understanding of the resistance of ships in shallow water from the very basis is provided to build a new approach to improve resistance prediction considering the water-depth dependency of the three features mentioned above. A method is proposed to improve the extrapolation of ship resistance for model-scale tests carried out in shallow water. The effects of limited water depths on the three components of ship resistance (i.e., frictional resistance, viscous pressure resistance, and wave-making resistance) have been studied individually. Empirical formulas have been developed for three ship types in various water depths. This approach can benefit all further qualities of the ship, e.g., a reliable performance prediction, truly valid rules for ship design and even future work on understanding ship propulsion in (extremely) shallow water when navigating in inland waterways and coastal waters. It also allows the further application of the well-accepted extrapolation method with at the same time taking into account the inherent deviations in shallow water.Ship Design, Production and Operation

Development of A Composite Indicator for Measuring Company Performance from Economic and Environmental Perspectives: A Study on Motor Vehicle Manufacturers

Company performance measurement is fundamental for decision-makers to monitor a company's performance and to solve management problems. The evolution of company performance measurement tools started from a pure financial-biased framework. The first generation of company performance measurement tools was achieved through supplementing the traditional financial measures with non-financial measures. The second generation addressed the dynamic of value creation by investigating transformations of resources. Both the first and the second generation showed appropriateness in how they reflect the realities in companies. The third generation emphasized the business-oriented methodology to real free cash flow activities. This dissertation, that will present a fourth generation company performance measurement tool, has a focus on motor vehicle manufacturers (MVMs) due to its economic significance and its environmental impact during vehicles' production.Transport Engineering and Logistic

On the viscous resistance of ships sailing in shallow water

Accurate resistance prediction for ships sailing in vertically restricted waterways is highly required to improve the design and operation for large ships entering harbors and for vessels navigating in inland waters. The methods derived from deep water may lead to large errors, and studies considering shallow water effects are needed. As most ships sailing in shallow water operate at a low Froude number, the viscous resistance dominates the total resistance and becomes the main concern. In this study, a Wigley hull and the KCS (KRISO Container Ship), which have available benchmark data, are applied. A typical 86 m long inland ship is then chosen to further investigate the influence of a different hull form. Results show that the friction and the viscous pressure resistance depend on ship types, speeds, and water depths. A formula to predict a ship's friction in shallow water is given with some constants determined based on ship's characteristics. A form factor defined based on computed ship's friction is suggested, and an empirical expression is provided for each ship applied. With the investigations for three ship forms, this study is expected to provide inspirations to further improve the prediction of ship's viscous resistance in shallow water.Accepted Author ManuscriptShip Design, Production and OperationsShip Hydromechanics and Structure

Exploring company performance measurement for truck manufacturers

This paper aims to develop a quantitative model of company performance from an inventory perspective for truck manufacturers. With the inventory performance as a new dimension, fourteen indicators are identified to form a conceptual framework for truck manufacturers to measure their company performance. Accordingly, techniques of the fuzzy logic and the analytic network process (ANP) are used to generate the quantitative model, considering the interdependency between the indicators and the uncertainty arising from human qualitative judgments. A case study is conducted in nine truck manufacturers, with time series data from the fiscal year 2004 to 2015. The ranking result out of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is used as a validation, which proves the higher accuracy of the model developed.Transport Engineering and Logistic

Multi-level Indoor Path Planning Method

Indoor navigation is increasingly widespread in complex indoor environments, and indoor path planning is the most important part of indoor navigation. Path planning generally refers to finding the most suitable path connecting two locations, while avoiding collision with obstacles. However, it is a fundamental problem, especially for 3D complex building model. A common way to solve the issue in some applications has been approached in a number of relevant literature, which primarily operates on 2D drawings or building layouts, possibly with few attached attributes for obstacles. Although several digital building models in the format of 3D CAD have been used for path planning, they usually contain only geometric information while losing abundant semantic information of building components (e.g. types and attributes of building components and their simple relationships). Therefore, it becomes important to develop a reliable method that can enhance application of path planning by combining both geometric and semantic information of building components. This paper introduces a method that support 3D indoor path planning with semantic information.UrbanismArchitecture and The Built Environmen

A modification of the ITTC57 correlation line for shallow water

The ITTC57 correlation line, which is derived based on the assumption that the water in which ships advance is infinite deep and wide. However, for ships sailing in the waterway with limited water depth, the frictional resistance will be influenced leading to a decreasing accuracy of the prediction with this correlation line. In this study, a modification of the ITTC57 correlation line is proposed to correct the effects in very shallow water specifically for the flat area of the bottom of the ship. Under some assumptions, this area can be simplified to a 2D flat plate with a parallel wall close to it to study how the shallow water conditions of two interacting boundary conditions are affecting the flat plate friction coefficient. Computational fluid dynamics (CFD) calculations are applied to investigate how a friction line specifically in shallow water deviates from the conventional lines. Such deviations may severely affect the extrapolation of a ship model’s resistance to full scale and, therefore, the accuracy of ship’s performance prediction. Cases at ten Reynolds numbers from 105 to 109 are simulated on the 2D flat plate. Seven different distances between the flat plate and the parallel wall were chosen to generate various shallow water conditions, and consequently, a database including frictional resistance coefficients, Reynolds numbers and the distance between those two walls is built. Results indicate that thinner boundary layers are observed in shallow water conditions, and the scale effects which has a significant impact on resistance extrapolation are also observed. Furthermore, the assumption of the zero pressure gradients (ZPG) which is commonly used in deep water is no longer valid in extremely shallow ones. Finally, a modification for the ITTC57 correlations line considering shallow water effects is proposed, which is willing to improve the prediction of the frictional resistance of those ships with a large area of flat bottom and sail in shallow water.Ship Design, Production and OperationsShip Hydromechanics and Structure

Scale effects on the wave-making resistance of ships sailing in shallow water

The conventional extrapolation of ship resistance from model tests to full scale presumes that the coefficient of wave-making resistance (Cw) depends on the Froude number only. This leads to the assumption that Cw of a ship is identical to Cw of its scaled model. However, this assumption is challenged in shallow water due to viscous effects, which are represented by the Reynolds number (Re). In this study, different scales (different Re) of the Wigley hull and the KCS hull are used to investigate the scale effects on Cw numerically. After verification and validation, systematic computations are performed for both ships and their scaled models in various shallow-water conditions. Based on the results, significantly larger values of Cw are found for the KCS at model scale in very shallow water, suggesting that the conventional extrapolation has to be reconsidered. Additionally, this study reveals the relationship between the changes in frictional resistance coefficient (Cf) and the changes in Cw caused by shallow water, which benefits the prediction of shallow water effects on Cw. Finally, use of a larger ship model, where the Re is also higher, is recommended for resistance tests in shallow water to reduce scale effects on Cw.Ship Design, Production and OperationsShip Hydromechanics and StructuresMarine and Transport Technolog

A company performance index for motor vehicle manufacturers: company performance measurement with environmental concerns

Purpose: Current literature presents limited measurement methods of quantifying manufacturers' performance with environmental concerns. The purpose of this paper is to construct a company performance index for benchmarking motor vehicle manufacturers (MVMs) with environmental concerns. Design/methodology/approach: Methods of constructing the index include regression analysis, a modified linear method for normalizing variables and a geometric mean for aggregating variables into a single index IMVM (index for MVMs). A case study is conducted in 12 MVMs from 2008 to 2017. A sensitivity analysis with the simple additive weighting method is performed to analyze how different aggregation methods affect the final value. The index IMVM is assessed through a benchmark with three existing indices. Findings: Three realistic considerations are identified from MVMs, based on which proper and transparent methods are chosen to construct the IMVM. The construction of the index IMVM has been assessed through a benchmark against the methodologies of three other indices. The results indicate that the new measurement is feasible and effective for MVMs to measure their company performance from an environmental perspective. Practical implications: The construction of the index IMVM can support policymakers with accurate statistics for decision-making. As a response to current imperative climate policies, this paper raises awareness of CO2 emissions in vehicles' production. For statistical organizations and stakeholders in the investment world, this paper provides available and reliable statistics for trend analysis of different MVMs. Originality/value: A new method is designed for constructing a company performance index for MVMs. Three environmental variables are identified based on literature, their environmental impact as well as their data availability from public documents. A ranking by manufacturer with environmental concerns is generated. This index can contribute with available statistics and useful insights toward decision-making.Accepted Author ManuscriptTransport Engineering and LogisticsMarketing and Consumer Researc

Company performance measurement for automobile companies: A composite indicator from an environmental perspective

Current research in the field of performance measurement hasn't presented a rigorous composite indicator for quantifying company performance, with environmental indicators for automobile companies. This paper aims to construct this missing composite indicator. A new approach is developed, including techniques of fuzzy logic, analytic network process, the entropy theory and a geometric mean with unequal weights. The method is transparent, and the composite indicator derived can serve as a statistical tool for benchmarking. A case study is conducted in six leading automobile companies with data from the fiscal year 2016.Accepted Author ManuscriptTransport Engineering and LogisticsMarketing and Consumer Researc