Towards a Measurement Theory for Off-Shell Quantum Fields

In this study, we develop quantum measurement theory for quantum systems described by C*-algebras. This is the first step to establish measurement theory for interacting quantum fields with off-shell momenta. Unlike quantum mechanics (i.e., quantum systems with finite degrees of freedom), measurement theory for quantum fields is still in development because of the difficulty of quantum fields that are typical quantum systems with infinite degrees of freedom. Furthermore, the mathematical theory of quantum measurement is formulated in the von Neumann algebraic setting in previous studies. In the paper, we aim to extend the applicable area of quantum measurement theory to quantum systems described by C*-algebras from a mathematical viewpoint, referring to the sector theory that is related to symmetry and based on the theory of integral decomposition of states. In particular, we define central subspaces of the dual space of a C*-algebra and use them to define instruments. This attempt makes the connection between measurement theory and sector theory explicit and enables us to understand the macroscopic nature and the physical meaning of measurement.

PERAN KELUARGA DALAM MEWUJUDKAN TAKAFUL IJTIMA'I ( Studi Kajian Hukum Keluarga dan Ekonomi Islam)

as the smallest institution in society, the family has the potential for enormous influence on common prosperity. This is closely related to the function of the family as a container for the formation of quality human resources. If accordingly mentioned, then for the first step, every family must pay attention to the welfare of their own families afterwards to take a pay attention to other families in the surrounding environment. This attention is none other than the form of mu'amalah which is based on a sense of mutual assistance. Therefore, it is only natural that all components of society are obliged to build the welfare of their respective families. This is implemented in order to create a social balance in the form of welfare. Focus point in this study of the writer lies on the role of the family to realize the balance of welfare, especially in the economic field, through the concept of takaful. This research was conducted using qualitative-descriptive methods that contain primary and secondary data about family welfare and takaful which can be applied as a whole to the community sector. theory development in this study uses the theory of construction where the role of the deconstruction of family welfare can realize takaful ijtima'i.

AGRICULTURAL EMPLOYMENT TRANSFORMATION IN FRANCE

Research on sectoral employment is an important part of economic investigation devoted to structural change, traditionally referred to when describing economic growth. At the same time, agricultural employment has been traditionally studied as an important feature characterizing rural economies. The main aim of the paper is to investigate agricultural employment transformation in France from the beginning of the twentieth century. Specific objectives include the presentation of changes in agricultural employment in France as well as their main determinants. A theoretical concept of the three sectors by Colin Clark, Jean Fourastié and Allan Fisher was referred to. It can be concluded that France is now in the “completion phase”, with the service sector dominating the employment structure. However, the French economy never experienced a real period of industrial predominance specified in the three-sector theory. Current issues in agricultural employment in France include the ageing of farmers, newcomers (already related to agriculture by their family or outsiders), increasing involvement of women as well as flows between sectors (agriculture is not a lifelong profession any more).

Productive of the Service Sector: Theory and Practice of Corruption Declining

Corruption contracts are, throughout the democratic world, illegal and considered immoral. Their participants thus cannot use standard procedures to find a second party, to negotiate the content of the contract, to check if it performs what was promised, and to enforce the promises. This increases the risks associated with the contract. Illegality or immorality of the contract makes both parties more vulnerable – each party can threaten to reveal the contract and denounce the second party. Connecting a corruption contract with a previously established legal contract is usually seen as the best way to reduce risks and to reinforce the corruption contract. Owing to legal contacts and contracts, potential parties interested in corruption know where they should seek a counterparty and what to offer. At the same time, the corruption contract is tied to legal contracts, and failure to fulfil conditions of the corruption contract may put such legal contract at risk, therefore there is a higher probability that both parties to the corruption contract would fulfil what was promised and that there will be no extortion by any of the parties to demand additional fulfilment after the end of the corruption contract or that the corruption contract will not be disclosed. This paper presents the opposite approach in which a corruption contract is established as the first and it creates the base for further often legal but immoral contracts. All contracts lead to the mutually advantageous affinity of all its participants who often become members of corruption networks. The article presents the model when a blackmailed or dependent person must participate in corruption contracts, otherwise, it faces serious problems. But sooner or later, participation will begin to bring him benefits, so he becomes dependent on the network, although initially, he had moral inhibitions to participate in its activities. The subjects looking a counterparty of the corruption contract thus often create the environment of dependency and blackmailing and when people that are obliged to corruption lose their scruples and they see corruption as the common behaviour. Our model comes from real corruption networks in the Czech Republic. Some of them are briefly analysed. Theory of corruption must pay higher attention to all factors contributing to the spread of corruption behaviour, including mutual dependence and extortion Keywords: blackmailing, corruption, corruption networks, corruption risks, mutual dependency

Labor Market Modeling and the Urban Informal Sector: Theory and Evidence

The purpose of this chapter is to assess the compatibility between theoretical models of the urban informal sector (UIS) and empirical evidence on the workings of that sector in the context of developing countries’ labour markets. The major point is that, although the UIS is an excellent idea which has served us well in the 1970s and 1980s, there is a need in the next round of research to refine the terminology and the models in light of empirical findings which have come to the fore in the interim. Wage employment or self-employment in small-scale units may be better than or worse than employment in the formal sector. This is not a new point: diversity of earning opportunities and other job characteristics within the informal sector has long been noted. But only recently has this view come to the fore.