Search results
1 – 10 of over 2000This study aims to propose a theoretical model to characterize the optimal forward freight agreement (FFA) procurement strategies and investigate the determinants of FFA trading…
Abstract
Purpose
This study aims to propose a theoretical model to characterize the optimal forward freight agreement (FFA) procurement strategies and investigate the determinants of FFA trading activities from a new cross-market perspective.
Findings
A two-step model specification is used to empirically test the theoretical results for the Capesize, Panamax and Supramax sectors. It is found that spot demand has a positive relation with FFA trading volume for all three sectors. Moreover, spot demand volatility has a negative relation, while the correlation between spot demand and spot rate has a positive relation with FFA trading volume for the Capesize and Panamax sectors.
Originality/value
The results show that the expected spot demand is scaled by a “quantity premium,” which is the product of a demand covariance term, a demand riskiness term and a demand volatility term. This can be used by the traders in the FFA market to construct their hedging strategies.
Details
Keywords
Fentahun Moges Kasie, Glen Bright and Anthony Walker
The purpose of this paper is to propose a decision support system (DSS) that stabilizes the flow of fixtures in manufacturing systems. The proposed DSS assists decision-makers to…
Abstract
Purpose
The purpose of this paper is to propose a decision support system (DSS) that stabilizes the flow of fixtures in manufacturing systems. The proposed DSS assists decision-makers to reuse or adapt the available fixtures or to manufacture new fixtures depending upon the similarity between the past and new cases. It considers the cost effectiveness of the proposed decision when an adaptation decision is passed.
Design/methodology/approach
The research problem is addressed by integrating case-based reasoning, rule-based reasoning and fuzzy set theory. Cases are represented using an object-oriented (OO) approach to characterize them by their feature vectors. The fuzzy analytic hierarchy process (FAHP) and the inverse of weighted Euclidean distance measure are applied for case retrieval. A machining operation is illustrated as a computational example to demonstrate the applicability of the proposed DSS.
Findings
The problems of fixture assignment and control have not been well-addressed in the past, although fixture management is one of the complex problems in manufacturing. The proposed DSS is a promising approach to address such kinds of problems using the three components of an artificial intelligence and FAHP.
Research limitations/implications
Although the DSS is tested in a laboratory environment using a numerical example, it has not been validated in real industrial systems.
Practical implications
The DSS is proposed in terms of simple rules and equations. This implies that it is not complex for software development and implementation. The illustrated numerical example indicates that the proposed DSS can be implemented in the real-world.
Originality/value
Demand-driven fixture retrieval and manufacture to assign the right fixtures to planned part-orders using an intelligent DSS is the main contribution. It provides special consideration for the adaptation of the available fixtures in a system.
Details
Keywords
Sun Jin, Kuigang Yu, Xinmin Lai and Yinhua Liu
The purpose of this paper is to focus on optimal sensor placement for the fixture variation diagnosis of compliant sheet metal assembly process. Fixture variations are the main…
Abstract
Purpose
The purpose of this paper is to focus on optimal sensor placement for the fixture variation diagnosis of compliant sheet metal assembly process. Fixture variations are the main sources for complex automotive body dimensional failures. An effective measurement strategy can help exactly and timely diagnose these fixture variations. Research on sensor placement strategy of compliant sheet metal assembly process is not much stated formerly.
Design/methodology/approach
The impact principle of fixture variations is analyzed to set up the relationship between the assembly variation and fixture variations applying the method of influence coefficients and the effective independence (EI) method is used to find the optimal sensor positions based on the impact principle analysis of fixture variations.
Findings
The obtained fixture variation sensitivity matrix describes the influence of fixture variations to compliant sheet metal assembly variation and can be used for diagnosing fixture variations. The EI method can effectively solve the optimal sensor positions for compliant sheet metal assembly by a case demonstration.
Originality/value
The proposed method can solve the sensor placement of online assembly station for diagnosing fixture variations. It takes the compliant characteristics of sheet metal parts into account and the sensor information has much greater diagnosability than that from applying other methods.
Details
Keywords
Aleksandar B. Menićanin, Mirjana S. Damnjanović and Ljiljana D. Živanov
The appropriate selection of a testing method largely determines the accuracy of a measurement. Parasitic effects associated with test fixture demand a significant consideration…
Abstract
Purpose
The appropriate selection of a testing method largely determines the accuracy of a measurement. Parasitic effects associated with test fixture demand a significant consideration in a measurement. The purpose of this paper is to introduce a measurement procedure which can be used for the characterization of surface mount devices (SMD) components, especially devoted to SMD inductors.
Design/methodology/approach
The paper describes measurement technique, characterization, and extracting parameters of SMD components for printed circuit board (PCB) applications. The commercially available components (multi‐layer chip SMD inductors in the ceramic body) are measured and characterized using a vector network analyzer E5071B and adaptation test fixture on PCB board. Measurement results strongly depend on the choice of the PCB; the behaviour of the component depends on the environment where the component is placed.
Findings
The equivalent circuit parameters are extracted in closed form, from an accurate measurement of the board‐mounted SMD inductor S‐parameters, without the necessity for cumbersome optimization procedures, which normally follow the radio frequency circuit synthesis.
Originality/value
It this paper, a new adaptation test fixture in PCB technology is realized. It is modeled and it has provided the extraction of parameters (intrinsic and extrinsic) of SMD inductor with great accuracy.
Details
Keywords
Hossein Rouhani, Alireza Fazlirad, Babak N. Araabi and Caro Lucas
Modern day manufacturing has seen the replacement of manual transfer of parts between press machines with automatic transfer systems. Higher automation productivity demands…
Abstract
Purpose
Modern day manufacturing has seen the replacement of manual transfer of parts between press machines with automatic transfer systems. Higher automation productivity demands greater flexibility of transfer devices. This paper deals with methods to improve the flexibility of fixtures designed to transfer parts between press machines.
Design/methodology/approach
Describes methods to improve the flexibility of fixtures designed to transfer parts between press machines in Press Shop 3 at Iran Khodro Company (IKCO). A fuzzy C means clustering‐based method is developed to optimize the number and arrangement of actuators for each fixture. Economical aspects of this novel design are addressed as well.
Findings
The simulation results suggest that application of a flexible fixtures system and use of linear motors was the best method of adding flexibility to the loader‐unloader system.
Originality/value
Provides evidence that flexible components are indispensable to increasing production speed and reliability in an automated system.
Details
Keywords
Graham J. Treloar, Andrew McCoubrie, Peter E.D. Love and Usha Iyer‐Raniga
The energy required to operate office buildings has been the focus of much research in the past three decades. There have been limited attempts to quantify the embodied energy…
Abstract
The energy required to operate office buildings has been the focus of much research in the past three decades. There have been limited attempts to quantify the embodied energy consumed in construction. Some embodied energy studies have been relatively detailed. But the energy embodied in fixtures, fittings and furniture which is used by occupiers of buildings is rarely mentioned. The potential significance of the energy embodied in fixtures, fittings and furniture has yet to be established. Aims to establish the likely importance of the energy embodied in fixtures, fittings and furniture relative to other life cycle energy requirements of office buildings in temperate climates. Implementation actions are suggested for the optimisation of the energy embodied in fixtures, fittings and furniture used in buildings. Assists facility managers and businesses with their decision making with respect to the environmental impacts associated with energy use throughout the life cycle of their buildings.
Details
Keywords
Fentahun Moges Kasie and Glen Bright
This study aims to propose a decision support system (DSS) that performs a decision-based part-fixture assignment and fixture flow control in planned production periods.
Abstract
Purpose
This study aims to propose a decision support system (DSS) that performs a decision-based part-fixture assignment and fixture flow control in planned production periods.
Design/methodology/approach
The principal approaches were fuzzy case-based reasoning (FCBR) and discrete-event simulation (DES). Besides, the fuzzy analytic hierarchy process (FAHP), an object-oriented (OO) method and a fuzzy weighted Euclidean distance were used to support the decision-making process.
Findings
It shows that integrating FCBR and DES systems is a promising approach to address part-fixture planning problems. The FCBR subsystem proposed various stable numbers of fixtures as scenarios. The DES model analyzed the future performances of these scenarios and identified the best alternative.
Research limitations/implications
The DSS was tested in laboratory environments using a numerical analysis; however, it was not validated in industrial situations.
Originality/value
The synergy of integrating FCBR and DES systems was not exploited in the past in part-fixture assignment and fixture flow control problems.
Details
Keywords
John A. Bryant and Kimberly Carlson
Engineers at the Energy Systems Laboratory at Texas A&M University conducted short term energy metering studies at a complex of offices in northern Texas and several buildings on…
Abstract
Engineers at the Energy Systems Laboratory at Texas A&M University conducted short term energy metering studies at a complex of offices in northern Texas and several buildings on the Texas A&M University campus. These studies typically consisted of installing electrical metering at the whole building level and included sub‐metering of selected circuits when possible. A staged shut‐down sequence was performed for all lighting, fan, and mechanical systems of interest in the facility. Lighting system load verification was the primary goal. The study was a follow‐up to an earlier lighting study that had been conducted by the campus energy office. Base electrical load data were also determined from these tests, and in both studies significant “base” electrical loads were found. This paper presents results of these studies and suggests that the method is attractive to both contractors and facility energy managers as well.
Details
Keywords
R.J. Sutherland and M. Haworth
One of the principal findings of the most recent enquiry into professional football was that: “Running a successful league club is now a major commercial activity”. In general…
Abstract
One of the principal findings of the most recent enquiry into professional football was that: “Running a successful league club is now a major commercial activity”. In general terms, professional football clubs too were confronted with financial and management problems.
This paper reports on the planning, introduction, and implementation of surface mount technology (SMT) for printed circuit board assembly at Convergent Technologies. It is written…
Abstract
This paper reports on the planning, introduction, and implementation of surface mount technology (SMT) for printed circuit board assembly at Convergent Technologies. It is written from the production personnel's view‐point. The report starts with a brief history of the company, describes its dynamic environment, outlines the factors that led to the decision to implement SMT and provides the time‐frame for said implementation. With this background the paper then deals at length with design and manufacturing issues and questions that arose during this undertaking. The report concludes with a summary that outlines the benefits and concerns of SMT and highlights the future trends for this technology.