A characterization of cooperative TU-games with large monotonic core

[cat] El concepte de joc cooperatiu amb large core és introduït per Sharkey (1982) i el de Population Monotonic Allocation Scheme és definit per Sprumont (1990). Inspirat en aquests conceptes, Moulin (1990) introdueix la noció de large monotonic core donant una caracterització per a jocs de tres jugadors. En aquest document provem que tots els jocs amb large monotonic core són convexes. A més, donem un criteri efectiu per determinar si un joc té large monotonic core o no, i daquí obtenim una caracterització pel cas de quatre jugadors.

A characterization of cooperative TU-games with large monotonic core

[cat] El concepte de joc cooperatiu amb large core és introduït per Sharkey (1982) i el de Population Monotonic Allocation Scheme és definit per Sprumont (1990). Inspirat en aquests conceptes, Moulin (1990) introdueix la noció de large monotonic core donant una caracterització per a jocs de tres jugadors. En aquest document provem que tots els jocs amb large monotonic core són convexes. A més, donem un criteri efectiu per determinar si un joc té large monotonic core o no, i daquí obtenim una caracterització pel cas de quatre jugadors.

On the structure of cooperative and competitive solutions for a generalized assignment game

We study cooperative and competitive solutions for a many- to-many generalization of Shapley and Shubik (1972)'s assignment game. We consider the Core, three other notions of group stability and two al- ternative definitions of competitive equilibrium. We show that (i) each group stable set is closely related with the Core of certain games defined using a proper notion of blocking and (ii) each group stable set contains the set of payoff vectors associated to the two definitions of competitive equilibrium. We also show that all six solutions maintain a strictly nested structure. Moreover, each solution can be identified with a set of ma- trices of (discriminated) prices which indicate how gains from trade are distributed among buyers and sellers. In all cases such matrices arise as solutions of a system of linear inequalities. Hence, all six solutions have the same properties from a structural and computational point of view.

Review of Robust Cooperative Spectrum Sensing Techniques for Cognitive Radio Networks

Cognitive radio networks sense spectrum occupancy and manage themselvesto operate in unused bands without disturbing licensed users. The detection capability of aradio system can be enhanced if the sensing process is performed jointly by a group of nodesso that the effects of wireless fading and shadowing can be minimized. However, taking acollaborative approach poses new security threats to the system as nodes can report falsesensing data to reach a wrong decision. This paper makes a review of secure cooperativespectrum sensing in cognitive radio networks. The main objective of these protocols is toprovide an accurate resolution about the availability of some spectrum channels, ensuring thecontribution from incapable users as well as malicious ones is discarded. Issues, advantagesand disadvantages of such protocols are investigated and summarized.

Developing the Sourcing with the Purchasing Tool in the Chemical Company

The aim of this research was to investigate Tikkurila Oyj's Vantaa factories' current status in procurement and to develop the reporting of purchases and purchase warehouses, and to measure the activities during the implementation of the new purchasing tool. The implemented purchasing tool was based on ABC-analysis. Based on its reports the importance of performance measurements for the operations of the company, and the purpose of getting transparency to the company's supply chain on the part of purchasing were examined. A successful purchase- and material operation calls for accurate knowledge and professional skills. The research proved that with a separate purchasing tool, that analyses the existing information of the company's production management system, it is possible to get added value to whole supply chain's needs. The analyses and reports of the purchasing tool enable a more harmonized purchasing process at the operative level, and create a basis for internal targets and to their follow-up. At the same time the analyses clarify the current status and development trends of procurement fresh to the management. The increase of the possibilities of exploitation of information technology enables a perfect transparency to the case company's purchase department.

Role of Capabilities in Purchasing and Supply Management Performance

The objective of this thesis was to study the role of capabilities in purchasing and supply management. For the pre-understanding of the research topic, purchasing and supply management development and the multidimensional, unstructured and complex nature of purchasing and supply management performance was studied in literature review. In addition, a capability-based purchasing and supply management performance framework were researched and structured for the empirical research. Due to the unstructured nature of the research topic, the empirical research is three-pronged in this study including three different research methods: the Delphi method, semi-structured interview, and case research. As a result, the purchasing and supply management capability assessment tool was structured to measure current level of capabilities and impact of capabilities on purchasing and supply management performance. The final results indicate that capabilities are enablers of purchasing and supply management performance, and therefore critical to purchasing and supply performance.

Purchasing portfolio analysis and supplier classification

The purpose of the thesis is to classify suppliers and to enhance strategic purchasing in the case company. Supplier classification is conducted to fulfill the requirements of the company quality manual and international quality standards. To gain more benefit, a strategic purchasing tool, Kraljic’s purchasing portfolio and analytical hierarchy process are utilized for the base of supplier classification. Purchasing portfolio is used to give quick and easy visual insight on product group management form the viewpoint of purchasing. From the base on purchasing portfolio alternative purchasing and supplier strategies can be formed that enhance the strategic orientation of purchasing. Thus purchasing portfolio forces the company to orient on proactive and strategic purchasing. As a result a survey method for implementing purchasing portfolio in the company is developed that exploits analytical hierarchy process. Experts from the company appoint the categorization criteria and in addition, participate in the survey to categorize product groups on the portfolio. Alternative purchasing strategies are formed. Suppliers are classified depending on the importance and characteristics of the product groups supplied.

Assessment of purchasing maturity in spare parts supply chain

To describe the change of purchasing moving from administrative to strategic function academics have put forward maturity models which help practitioners to compare their purchasing activities to industry top performers and best practices. However, none of the models aim to distinguish the purchasing maturity from the after-sales point of view, even though after-sales activities are acknowledged as a relevant source of revenue, profit and competitive advantage in most manufacturing firms. The maturity of purchasing and supply management practices have a large impact to the overall performance of the spare parts supply chain and ultimately to the value creation and relationship building for the end customer. The research was done as a case study for a European after-sales organization which is part of a globally operating industrial firm specialized in heavy machinery. The study mapped the current state of the purchasing practices in the case organization and also distinguished the relevant areas for future development. The study was based on the purchasing maturity model developed by Schiele (2007) and investigated also how applicable is the maturity model in the spare parts supply chain context. Data for the assessment was gathered using five expert interviews inside the case organization and other parties involved in the company’s spare parts supply chain. Inventory management dimension was added to the original maturity model in order to better capture the important areas in a spare parts supply chain. The added five questions were deduced from the spare parts management literature and verified as relevant areas by the case organization’s personnel. Results indicate that largest need for development in the case organization are: better collaboration between sourcing and operative procurement functions, use of installed base information in the spare parts management, training plan development for new buyers, assessment of aligned KPI’s between the supply chain parties and better defining the role of after-sales sourcing. The purchasing maturity model used in this research worked well in H&R Leading, Controlling and Inventory Management dimensions. The assessment was more difficult to conduct in the Supplier related processes, Process integration and Organizational structure –dimensions, mainly because the assessment in these sections would for some parts require more company-wide assessment. Results indicate also that the purchasing maturity model developed by Schiele (2007) captures the relevant areas in the spare parts supply as well.

Public and private sector cooperative opportunities in the Finnish healthcare internationalization : views from the public sector’s perspective

Traditionally mostly publicly provided Finnish healthcare services are confronted today by the evident challenge of rising healthcare costs as the expenditure on health and social case has exceeded Finland’s national GDP growth significantly since the new millennium. While the opening of the traditional barriers through the EU’s new patient directive resulting in increasing international competition and the free flow of patients within the EU present opportunities for the Finnish healthcare services industry there are also several challenges for the existing healthcare system as proposed by the Ministry of Employment and the Economy in 2011. Due to the structure and nature of the current Finnish healthcare service system the greatest potential for internationalization is seen from a joint cooperation of the public and private sectors in an internationalization network for Finnish healthcare services. As its formation has recently also taken as a strategic initiative to be completed by the Ministry of Employment and the Economy and no earlier research exists on how this is seen in practice by the network actors, the purpose of this study is to examine the proposed solution of forming an internationalization network between the public and private sector actors in Finland in practice from the viewpoint of public sector actors. The research relied heavily on the reports by the Finnish Ministries in understanding the current situation of the Finnish healthcare services internationalization and its potential. Suitable theories were also used to build a more comprehensive view of the matter. The study applied a qualitative research approach on the explorative research problem. The data collection was achieved through expert interviews in two of the largest Finnish public healthcare service providers; the Turku and Helsinki Central University Hospitals. Expert interviews were considered as the most suitable method for data collection in order to create an in-depth understanding of the topic within the limitations of this thesis. In turn, two different public healthcare service providers were chosen to give a broader view of the field instead of focusing on a specific unit and also to allow a possible comparison between the two different organizations. The latter however was shown not to be suitable for the purposes of this study as the opinions of the respondents varied largely also within their own organizations. The conclusion is that while the actors agree on the evident internationalization of Finnish healthcare services, there are several large-scale structural challenges effectively preventing such activities while at the same time the opportunities within Finland vary, as there are several niches but no real large-scale advantages in the highly competitive industry. Interest towards cooperation between the sectors are seen especially in exploiting the advantages offered by the private sector in commercialization and marketization, yet however no clear views exist on how these activities should be governed or structured in the short-term as a larger reform of the entire Finnish healthcare service sector is needed in the long-term.

Raise All Ships: Cooperative Repository Strategies in a Boot-Strap Culture

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014