126 research outputs found
Corporate Governance Rating and Family Firms: The Greek Case
Corporate governance (CG) studies have mostly focused on highly dispersed corporations. However, there is an important need for research exploring the governance structure of family-owned firms. The main characteristics that distinguish the family firm from the other types of corporations are the presence of one or more controlling family and the involvement of the owners in the management. Family firm is the most common form of business in Greece. Hence, the governance structures and the performance of the family firms affect the growth opportunities of the capital market. The aim of the paper is to explore the main aspects of CG of family-owned listed companies in Greece. For this purpose, we apply a specific CG rating methodology, using five core CG criteria to distinguish family from non-family firms: shareholders' rights and obligations; transparency, disclosure of information and auditing; board of directors; CEO and executive management and corporate social responsibility and corporate governance commitment. The overall research objective of the study is to develop a CG rating methodology on the current state of corporate governance in Greece. Each firm is rated among the 120 total number of companies (both family-owned and widely- held). The results disclose the potential strengths and weaknesses of the existing corporate governance framework of the family-owned firms and provide specific policy recommendations.family firms, corporate governance rating, Greece
Aircraft Marshaling Signals Dataset of FMCW Radar and Event-Based Camera for Sensor Fusion
Dataset Introduction
The advent of neural networks capable of learning salient features from variance in the radar data has expanded the breadth of radar applications, often as an alternative sensor or a complementary modality to camera vision. Gesture recognition for command control is the most commonly explored application. Nevertheless, more suitable benchmarking datasets are needed to assess and compare the merits of the different proposed solutions. Furthermore, most current publicly available radar datasets used in gesture recognition provide little diversity, do not provide access to raw ADC data, and are not significantly challenging. To address these shortcomings, we created and made available a new dataset that combines two synchronized modalities: radar and dynamic vision camera of 10 aircraft marshalling signals at several distances and angles, recorded from 13 people. Moreover, we propose a sparse encoding of the time domain (ADC) signals that achieve a dramatic data rate reduction (>76%) while retaining the efficacy of the downstream FFT processing (<2% accuracy loss on recognition tasks). Finally, we demonstrate early sensor fusion results based on compressed radar data encoding in range-Doppler maps with dynamic vision data. This approach achieves higher accuracy than either modality alone.
Dataset Structure
The dataset has a common directory structure which contains additional information about the captures.
dataset_dir///--/ofxRadar8Ghz_yyyy-mm-dd_HH-MM-SS.rad
Identifiers
stage [train, test].
room: [conference_room, foyer, open_space].
person: [0-9]. Note that 0 stands for no person, and 1 for an unlabeled, random person (only present in test).
gesture: ['none', 'emergency_stop', 'move_ahead', 'move_back_v1', 'move_back_v2', 'slow_down' 'start_engines', 'stop_engines', 'straight_ahead', 'turn_left', 'turn_right'].
distance: ['xxx', '100', '150', '200', '250', '300', '350', '400', '450'] (in cm). Note that xxx is used for none gestures when there is no person present in front of the radar (i.e. background samples), or when a person is walking infront of the radar with varying distances but performing no gesture.If you use this dataset, please also cite our accompanying paper:
@inproceedings{mueller2023aircraft, title={Aircraft Marshalling Signals Dataset of Radar and Event-Based Camera for Sensor Fusion}, author={M\"uller, Leon and Sifalakis, Manolis and Eissa, Sherif and Yousefzadeh, Amirreza and Detterer, Paul and Stuijk, Sander, and Corradi, Federico}, journal={IEEE Radar Conference, San Antonio, TX}, volume={}, number={1}, pages={1--15}, year={2023}, publisher={IEE}
Can Corporate Governance be Rated? Ideas based on the Greek experience
The paper presents an attempt to quantify the compliance of Greek companies with international best practices. Based on 37 indicators (composed out of 54 questions) it was found that Greek companies demonstrate a fairly satisfactory degree of compliance with OECD guidelines. Their weak points lie in: the role of stakeholders and corporate social responsibility; the organisation of CG; the effective role of the independent members of the board (which may be attributed to the small size of the pool of potential independent board members); disclosure of remuneration; and risk management. Methodologically, the merit of the exercise lies in its approach towards the creation of "collectively subjective" weightings, an effort to discuss the benefits of separating the rating of the market from the rating of companies and the discussion on typologies of work that can be effectively performed through rating exercises. Copyright Blackwell Publishing Ltd. 2004.
Loose ends: almost one in five human genes still have unresolved coding status
The authors have accidently omitted one co-author. Part of the work described in this study was performed in the laboratory of Dr Manolis Kellis, Computer Science and Electrical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA and The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
Dr Kellis’ name has been added to the authorship and the published article has been updated
Cognitive abstraction approach to sketch-based image retrieval
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 151-157).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.As digital media become more popular, corporations and individuals gather an increasingly large number of digital images. As a collection grows to more than a few hundred images, the need for search becomes crucial. This thesis is addressing the problem of retrieving from a small database a particular image previously seen by the user. This thesis combines current findings in cognitive science with the knowledge of previous image retrieval systems to present a novel approach to content based image retrieval and indexing. We focus on algorithms which abstract away information from images in the same terms that a viewer abstracts information from an image. The focus in Imagina is on the matching of regions, instead of the matching of global measures. Multiple representations, focusing on shape and color, are used for every region. The matches of individual regions are combined using a saliency metric that accounts for differences in the distributions of metrics. Region matching along with configuration determines the overall match between a query and an image.by Manolis Kamvysselis and Ovidiu Marina.S.B.and M.Eng
The Construction of a Corporate Governance Rating System for a Small Open Capital Market: Methodology and Applications in the Greek Market
An investigation of price - volume intraday patterns under "Bull" and "Bear" market conditions
There has been a common belief among stock market practitioners that stock prices move along with trading volume creating certain patterns in price and volume formation. Nevertheless, the above argument was hardly recognised by the academic community since for a number of years statistical results indicated that the stock market is an efficient market i.e. a market where past available information is of no use in predicting future returns profitably, and/or non rational factors do not influence stock prices; The last decade the research for market efficiency was expanded and the use of new large data sets and advanced techniques indicated deviations from the predictions of the Efficient Market Hypothesis (E.M.H.). This study investigates whether there exists a relationship between stock returns and trading volume in the Athens Stock Exchange (A.S.E.) and if such a relationship forms evidence against the E.M.H. We believe that we add to the research in this area since we use intraday data and investigate for a possible relationship under different market states and for different categories of shares.peer-reviewe
Inverse identification of buffeting and self-excited wind loads on the hardanger bridge from acceleration data
The traditional wind load assessment for long-span bridges rely on assumed models for the wind field and aerodynamic coefficients from wind tunnel tests, which usually introduces some uncertainties. It is therefore desired to develop tools that can utilize full-scale vibration response data from existing bridges in order to study the wind loading in detail for in-situ conditions. This paper presents a novel case study of inverse identification of dynamic wind loads on the 1310 m long Hardanger bridge, a suspension bridge equipped with a network of accelerometers. The identification method used is an extented Kalman-type filter for joint input, state, and parameter estimation. A system model considering the still-air modes in addition to a quasi-steady submodel for the self-excited forces of the bridge is presente. The coefficients for self-excited lift and pitching moment are considered unknown and are jointly estimated with the buffeting forces.Dynamics of StructuresOffshore Engineerin
Corporate governance rating in a small open capital market: Methodology and applications in the Greek market
The need of institutional investors to evaluate the Corporate Governance (CG) practices of listed companies resulted in many attempts to construct the CG rating methodologies. This paper, in response to this situation, attempts to quantify the compliance of large capitalization Greek companies with international best practices. The methodology consists of a questionnaire reflecting the Greek CG code, which basically replicates the OECD principles. Other wellregarded CG codes are also taken into account. Then, a rating system based on CG indicators is constructed and applied for the years 2001 and 2003. The total rating results for the years 2001 and 2003 demonstrate a relatively satisfactory improvement. The highest compliance is in the category of shareholder rights, while weak compliance appears in the last category, which incorporates commitment to CG, CSR and the relations with shareholders. The exercise, using practically all agreed principles of the OECD, could demonstrate a reasonable degree of compliance of the average company rated. Its limitation in that respect is that it could not satisfy investigations on convergence. The indicators used are highly pertinent to measure compliance but not convergence, which is not within the initial targets and needs a longer time series analysis. The methodology is applied in a small open economy and may have significant implications in other similar capital markets. Methodologically, the merit of the exercise lies in its approach toward the creation of "collectively subjective" weightings, and is valuable to institutional investors, policymakers, regulators and academics.
The upgrading of the Greeek capital market to a mature market status and the global competition for capital has boosted the CG debate in Greece. In addition, the recent corporate failures and financial scams around the world have increased awareness that proper CG is fundamental to the efficient operation of capital markets. The need of institutional investors to evaluate the CG practices of the listed companies resulted in many attempts to construct CG rating methodologies. This paper presents an attempt to quantify the compliance of large capitalization Greek companies with international best practices. Firstly, the literature on CG ratings is reviewed. Secondly, a brief history of the CG in Greece is presented. Then, the structure of our CG rating methodology and the results are described. Finally, the findings and proceedings with some critical points are summarized
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