Beam search heuristics for the single machine scheduling problem with linear earliness and quadratic tardiness costs

In this paper, we consider the single machine scheduling problem with linear earliness and quadratic tardiness costs, and no machine idle time. We present heuristic algorithms based on the beam search technique. These algorithms include classic beam search procedures, as well as the filtered and recovering variants. Several dispatching rules are considered as evaluation functions, in order to analyse the effect of different rules on the effectiveness of the beam search algorithms. The computational results show that using better rules indeed improves the performance of the beam search heuristics. The detailed, filtered and recovering beam search procedures outperform the best existing heuristic. The best results are given by the recovering and detailed variants, which provide objective function values that are quite close to the optimum. For small to medium size instances, either of these procedures can be used. For larger instances, however, the detailed beam search algorithm requires excessive computation times, and the recovering beam search procedure then becomes the heuristic of choice.scheduling, single machine, linear earliness, quadratic tardiness, beam search, heuristics

Bank Capital Requirements, Business Cycle Fluctuations and the Basel Accords: A Synthesis

In order to survey the mechanisms through which the introduction of Basel II bank capital requirements is likely to accentuate the procyclical tendencies of banking, this paper brings together the theoretical literature on the bank capital channel of propagation of exogenous shocks and the literature on the regulatory framework of capital requirements under the Basel Accords. We conclude that, although the theoretical models that revisit the bank capital channel under the new Accord generally support the Basel II procyclicality hypothesis, this issue is still subject to some debate. In particular, the magnitude of the procyclical effects under Basel II should essentially depend on (i) the composition of banks' asset portfolios, (ii) the approach adopted by banks to compute their minimum capital requirements, (iii) the nature of the rating system used by banks, (iv) the view adopted concerning how credit risk evolves through time, (v) the capital buffers over the regulatory minimum held by the banking institutions, (vi) the improvements in credit risk management, and (vii) the supervisor and market intervention under Basel II.Bank Capital Channel, Basel Accords, Business Cycles, Procyclicality

Technological-Knowledge Dynamics in Lab-Equipment Models of Quality Ladders

The Perpetual Inventory Model (PIM) assumes that, in each period, an arbitrary constant fraction of technological-knowledge stock is lost. By connecting the aggregate resource constraint with firms’ market value, we give a theoretical background to the PIM by showing that the technological-knowledge accumulation follows a dynamic process with an endogenous depreciation rate, which remains stable in steady state. Moreover, we relate different concepts of technological-knowledge used in the literature.endogenous growth, endogenous depreciation rate, Perpetual Inventory Model, technological-knowledge dynamics

Stylized Facts and Other Empirical Evidence on Firm Dynamics, Business Cycle and Growth

In this paper, we bring together in a systematised fashion the scattered empirical evidence relating firm dynamics and both short-run and long-run macroeconomic dynamics. There are numerous studies that focus on firm-level data while controlling for macroeconomic conditions, which cover a considerable range of variables, industries and countries. From these studies it has emerged what is by now a rather robust set of empirical regularities, or stylized facts, about entry, exit, growth and the size distribution of firms. On the contrary, the literature that focus explicitly on the interplay between firm dynamics and the business cycle is roughly confined to the US experience and to the cyclical properties of firm entry and exit, whereas systematic studies about the relationship between firm dynamics and economic growth are almost non-existent whatsoever.empirical evidence, firm dynamics, business cycle, economic growth

The transition to IFRS: disclosures by Portuguese listed companies

In the context of the CESR and of the Portuguese market regulator recommendations regarding the disclosure of the impacts of the transition to IFRS, this paper analyses the content of those disclosures by Portuguese listed companies. We found a high degree of variability among the disclosure either regarding the qualitative (narrative explanations of transition) or quantitative (reconciliations) disclosures. The results show that the objective of comparability, relevance and understandability stated in CESR’s recommendation were not achieved. Regarding accounting changes, the analysis shows that the reported impacts by companies confirmed expectations based on prior de jure studies on major impacts of changing from Portuguese GAAP to IFRS; these major impacts regard the recognition of intangibles, the accounting treatment of goodwill and financial instruments. Finally, Gray’s (1980) “conservatism” index was computed using the reconciliated profits to IFRS reported by companies. This analysis shows that Portuguese standards are more conservative than IFRS. This study is relevant to several parties: to the market regulators and policy makers in predicting the level of compliance with IFRS and calling attention for the importance of enforcement mechanisms; to the preparers, auditors and users in identifying the most problematic areas of implementation of IFRS.International Accounting, Disclosure, IAS/IFRS, Portugal

Greedy randomized dispatching heuristics for the single machine scheduling problem with quadratic earliness and tardiness penalties

In this paper, we present greedy randomized dispatching heuristics for the single machine scheduling problem with quadratic earliness and tardiness costs, and no machine idle time. The several heuristic versions differ, on the one hand, on the strategies involved in the construction of the greedy randomized schedules. On the other hand, these versions also differ on whether they employ only a final improvement step, or perform a local search after each greedy randomized construction. The proposed heuristics were compared with existing procedures, as well as with optimum solutions for some instance sizes. The computational results show that the proposed procedures clearly outperform their underlying dispatching heuristic, and the best of these procedures provide results that are quite close to the optimum. The best of the proposed algorithms is the new recommended heuristic for large instances, as well as a suitable alternative to the best existing procedure for the larger of the middle size instances.scheduling, single machine, early/tardy, quadratic penalties, greedy randomized dispatching rules

The core periphery model with asymmetric inter-regional and intra-regional trade costs

We generalize the model of Krugman (1991) to allow for asymmetric trade costs between regions and for (asymmetric) trade costs that are internal to the regions. We find that industrial activity, in a region, is enhanced by higher costs of importing and lower costs of exporting (more precisely, by a higher ratio between the two trade costs). This suggests that countries may impose tariffs on imported goods and seek to remove the import tariffs in other countries (unilateral protectionism) in order to foster industrial activity. Industrial activity is also promoted by lower domestic internal trade costs and higher foreign internal trade costs (more precisely, by a lower ratio between the two trade costs).New Economic Geography, Core-Periphery, Trade costs, Unilateral protectionism.

Educational Reform in Developing Countries: Private Involvement and Partnerships

The paper looks at recent changes in the role of government in the provision of education in Developing Countries. It begins with a reflection about the concept of public-private partnership (PPP), discusses the rationale that inspires the ‘contracting out’ of educational services and describes several cases of private sector involvement in education. After looking at the conditions for building PPPs and the necessary requirements for assuring an effective regulatory framework, the paper closes concluding that while contracting out needs not be made a priority there is a large room for other forms of private sector involvement in education in developing countries.Contracting out, educational reform, market/government failure, NPM, public-private partnerships.

Workart – A Gestão e a Arte

This paper looks into the intersection of art fields and management and tries to measure the positive impact that this brings into management, and shows how can art be a form of management consulting to companies. This form of consulting has been materialized, in the last six decades, in the Workart concept. In this paper we try to show the benefices, limitations and principle flaws of this concept. After the explanation, and history, of the concept, Workart, we present a method proposition. We’ve chosen the Learning Lab Denmark method, the CoLLab. We’ve tried to show the multiples layers of the method and, in a more practical sense, the steps needed to take to implement it. The presentation of this method is an illustration of the work needed to an efficient implementation of workart. Once the concept and method of implementation cleared we present two international working cases: the Unilever UK with Catalyst and the Babson Colleg with the entrepreneurial management MBA. The two cases are the practical application of the previous concepts and permit to see the goods and bads of this application in business and education. Then we focus in the Portuguese reality. In this field we present three cases: the Unicer, the Serralves Foundation and the Academia das Emoções. The first two cases are not conclusive because the Unicer program is not an intentional application of the Workart concept and has a lack of propose and the Serralves Foundation program has been cut down in an early stage of maturation without having material results. The last case, Academia das Emoções, although the short time of activity is the more mature and well succeed case in applying the Workart concept into Portuguese business reality. With this paper we try to show the benefices of applying the Workart concept in management, as a way of bringing creativity into companies, multiples angles to look to education, human resources issues and problem solving.Workart, Management, Art, Creativity, Innovation