A computer-aided diagnostic system to characterize CT focal liver lesions: design and optimization of a neural network classifier

In this paper, a computer-aided diagnostic (CAD) system for the classification of hepatic lesions from computed tomography (CT) images is presented. Regions of interest (ROIs) taken from nonenhanced CT images of normal liver, hepatic cysts, hemangiomas, and hepatocellular carcinomas have been used as input to the system. The proposed system consists of two modules: the feature extraction and the classification modules. The feature extraction module calculates the average gray level and 48 texture characteristics, which are derived from the spatial gray-level co-occurrence matrices, obtained from the ROIs. The classifier module consists of three sequentially placed feed-forward neural networks (NNs). The first NN classifies into normal or pathological liver regions. The pathological liver regions are characterized by the second NN as cyst or "other disease." The third NN classifies "other disease" into hemangioma or hepatocellular carcinoma. Three feature selection techniques have been applied to each individual NN: the sequential forward selection, the sequential floating forward selection, and a genetic algorithm for feature selection. The comparative study of the above dimensionality reduction methods shows that genetic algorithms result in lower dimension feature vectors and improved classification performance.

Investment Valuation with Tax-optimized Financing Decisions and a Tax-optimized Default Alternative

In this paper we evaluate an indivisible investment project that is carried out in a corporation under very simple premises. In particular, we discuss a one-period model with certainty, the pure domestic case and proportional tax rates. Surprisingly, the decision problem turns out to be rather complex if one has to make allowance for different taxation of the corporation and its owner. Altogether there are more than 10 cases that have to be distinguished if the firm's managers want to make a correct decision, depending on the relation of personal and corporate tax rates.

Thin Capitalization Rules and Entrepreneurial Capital Structure Decisions

Tax planners often choose debt over equity financing. As this has led to increased corporate debt financing, many countries have introduced thin capitalization rules to secure their tax revenues. In a general capital structure model we analyze if thin capitalization rules affect dividend and financing decisions, and whether they can partially explain why corporations receive both debt and equity capital. We model the Belgian, German and Italian rules as examples. We find that the so-called Miller equilibrium and definite financing effects depend significantly on the underlying tax system. Further, our results are useful for the treasury to decide what thin capitalization type to implement.

Labor participation in corporate policy-making decisions: West Germany's experience with codetermination

If workers are wealth maximizers, codetermination should lead to less risky investments, smaller dividends, reduced firm leverage, higher and more stable salaries, and more capital-intensive production processes. Unless codetermination also increases productivity by raising wokers' morale and satisfaction or reduces information asymmetries within the firm, shareholder wealth and firm value will decline. An analysis of West Germany's case, however, indicates that codetermination has little, if any, effect on corporate operations and performance.

Merger decisions and executive stock ownership in acquiring firms

This study supports the proposition that managerial welfare affects merger decisions. The abnormal stock returns experienced by bidder firms, from the time of the announcement of a merger bid through the stockholder approval date, are positively relaterd to the percentage of own-company stock held by the senior management of the bidder. The results suggest that substantial amounts of own-company share ownership help align the interests of stockholders and management.

Treatment decisions in 330 cases referred for apical surgery

INTRODUCTION Apical surgery is an important treatment option for teeth with postendodontic apical periodontitis. However, little information is available regarding treatment planning in cases referred for apical surgery. This study evaluated the decisions made in such cases and analyzed the variables influencing the decision-making process. METHODS The study retrospectively assessed clinical and radiographic data of 330 teeth that had been referred to a specialist in apical surgery with regard to the treatment decisions made in those teeth. The clinical and radiographic variables were divided into subcategories to analyze which factors influenced the decision-making process. RESULTS The treatment decisions included apical surgery (59.1%), tooth extraction (25.8%), no treatment (9.1%), and nonsurgical endodontic retreatment (6.1%). Variables that showed statistically significant differences comparing treatment decisions among subcategories included probing depth (P = .001), clinical attachment level (P = .0001), tooth mobility (P = .012), pain (P = .014), clinical signs (P = .0001), length (P = .041) and quality (P = .026) of the root canal filling, and size (P = .0001) and location (P = .0001) of the periapical lesion. CONCLUSIONS This study shows that apical surgery was the most frequently made treatment decision in teeth referred to a specialist in apical surgery, but every fourth tooth was considered nonretainable and was scheduled for extraction. The data showed that the most common variables that influenced the decision to extract teeth were teeth with an increased probing depth and tooth mobility and teeth presenting with lesions not located at the apex.

How Preliminary Are Preliminary Decisions?

The present research focuses on the question of whether even a preliminary decision causes a confirmation bias in order to maintain the status quo and examines individual differences in consistency between the preliminary and final decision and biased information processing. Dispositional Need for Closure (NFC, Webster & Kruglanski, 1994) was expected to predict revision or maintenance of the preliminary decision (decision consistency) after additional information on the issue was searched for and evaluated. Participants higher on dispositional NFC were less likely to change their preliminary decision than participants lower on dispositional NFC. Furthermore, the effect of NFC on decision consistency was fully mediated by biased information evaluation following the preliminary decision.

The gender typicality of faces and its impact on visual processing and on hiring decisions

Past research has shown that the gender typicality of applicants’ faces affects leadership selection irrespective of a candidate’s gender: A masculine facial appearance is congruent with masculine-typed leadership roles, thus masculine-looking applicants are hired more certainly than feminine-looking ones. In the present study, we extended this line of research by investigating hiring decisions for both masculine- and feminine-typed professional roles. Furthermore, we used eye tracking to examine the visual exploration of applicants’ portraits. Our results indicate that masculine-looking applicants were favored for the masculine-typed role (leader) and feminine-looking applicants for the feminine-typed role (team member). Eye movement patterns showed that information about gender category and facial appearance was integrated during first fixations of the portraits. Hiring decisions, however, were not based on this initial analysis, but occurred at a second stage, when the portrait was viewed in the context of considering the applicant for a specific job.