Defect Detection Using Unanimous Vote Among Mahalanobis Classifiers for Each Color Component

In manufacturing industries, product inspection is automated and the use of image data is increasingly being employed for defect detection. A manufacturing company in Japan produces an item and inspects the produced products using image data. Reducing the error rate is important in product inspection because poor inspection of products might lead to the delivery of defective products to consumers (consumer’s risk) and strict inspection increases production cost (producer’s risk). To reduce the error rate, we highlighted fault points using a two-dimensional moving range filter and discriminated defect production through a unanimous vote among Mahalanobis classifiers for each color component. For results, we achieved a lower error rate than the current system. This research is an empirical study of how to use image data in defect detection.     

INSTITUTIONAL INVESTORS,CORPORATE GOVERNANCE AND FIRM PERFORMANCE IN JAPAN

Since the beginning of the 2000s, institutional investors in Japan have become active in strengthening corporate governance, with the aim of achieving long‐term corporate value. The present paper examines the relationship between institutional investors and corporate governance, and also the relationship between institutional investors' shareholdings and firm performance. The results suggest that corporate governance has been enhanced by institutional investors. However, it is found that there is not a statistically significant difference between institutional investors' shareholdings and firm performance.     

WHY DO LARGE FIRMS TEND TO INTEGRATE VERTICALLY?

We provide a theoretical framework to discuss the relation between firm size and vertical structures. The framework is based on a Hotelling model with three downstream and three upstream firms. We show that vertical integration enhances the degree of product differentiation and show the strategic complementarity of product positioning. We also show that the downstream firm that has the largest market share is more likely to integrate vertically. Enhancing the degree of product differentiation is more beneficial for the large firm than for the rest of the downstream firms because the large firm supplies a large amount of product.     

Pre‐commitment to an Exclusive Contract under Partial Regulation

This article examines the welfare implications of an incumbent’s pre‐commitment to an exclusive contract in a partially regulated environment. It shows that the contract offered to customers in a competitive market makes the first‐best allocation infeasible in the partially regulated environment. However, the contract can have a welfare‐enhancing property through the exclusion of inefficient entry or cream skimming in the competitive market, especially when the regulated price ceiling is low and the incumbent’s technology is characterized by a large proportion of common cost in total cost.     

Delegating Infrastructure Projects with Open Access

This paper provides a simple model that examines a firm's incentive to invest in a network infrastructure through coalition formation in an open-access environment with a deregulated retail market. A regulator faces a dilemma between inducing an incentive for efficient investment and reducing the distortion generated by imperfect competition. We show that, in such a case, the degree of the cost-reducing effect of the investment is crucial from a welfare point of view. In particular, when network investment through coalition formation creates a large (small) cost-reducing effect, the regulator can (should not) delegate an investment decision to firms with an appropriate level of access charge.     

Elderly labor supply and fertility decisions in aging-population economies

With a longer life expectancy, individuals who plan to work when they are old may increase the number of their children. Therefore, when individuals choose the time of retirement, the fertility rate may not necessarily decline but even rise.     

Analysing Mechanism of an Economic Phase

In this paper, we define the thetical and antithetical phases of macroeconomy on a formal basis. And we formulate a bubble economy and its collapse by using these definitions. The concept of thetical and antithetical phases is introduced into economics by Kinoshita. In the course of discussion, we also make clear the difference between economic growth and bubble economy, while describing a mechanism of collapse of a bubble economy by using a simple macro-economic model instead of a specific model. As a result, we can analyse not only the state of thetical economy phase, and antithetical economy phase, but also bubble economy phase and bubble bursting economy phase. And we can describe mechanism of transitions among four economic phases.     

GRADUAL NETWORK EXPANSION AND UNIVERSAL SERVICE OBLIGATIONS

ABSTRACT 1 : Universal service obligations are usually not competitively neutral as they modify the way firms compete in the market. In this paper, we consider a continuum of local markets in a dynamic setting with a stochastically growing demand. The incumbent must serve all markets (ubiquity) possibly at a uniform price and an entrant decides on its market coverage before firms compete in prices. Connecting a market involves a sunk cost. We show that the imposition of a uniform price constraint modifies the timing of entry: for low connection cost markets, entry occurs earlier while for high connection cost markets, entry occurs later.     

Profit-enhancing competitive pressure in vertically related industries

Under a simple Cournot model with vertical relations, when downstream firms engage in process R&D, the profits of input suppliers for which upstream competition exists may be larger than those in which each input supplier has a bilateral monopoly relation with its buyer (downstream firm). This is because upstream competition leads to higher levels of investment by the downstream firms. Furthermore, we incorporate the decisions of downstream firms to acquire the ability to procure input from potential outside suppliers, which has the effect of placing competitive pressure on existing input suppliers. We show that no downstream firm acquires such an ability to procure its input from potential outside suppliers in some cases although the acquisition could benefit the input suppliers.     

Within-group heterogeneity and civil war

This study offers a bargaining model of conflict in which the government offers a transfer to an opposition group to preclude civil war. Members of the opposition are heterogeneous in income and ideology, and heterogeneity generates disagreement about whether to accept the government’s offer. We assume that the probability that the government’s offer will preclude conflict increases continuously with the number of opposition group members who agree to accept it. When within-group heterogeneity is large, the number of members who are receptive to the government’s offer is less responsive to an increase in the transfer level. In this situation, the government must substantially increase its transfer to attract the support of the opposition. Subsequently, as peace becomes more costly for the government, negotiations are likely to break down.