Chaotic Encryption and Privilege Based Visual Secret Sharing Model for Color Images

In the Privilege-based Visual Secret Sharing Model (PVSSM), each share has a unique privilege and a higher-privilege share contributes with more privilege to reveal the secret image. However, in PVSSM, when several shares with the higher priority are stacked, the secret image can be visibly displayed. This security problem is solved by applying a two-dimensional Logistic-Adjusted Sine Map (2D-LASM) to each share. This method is called Chaotic Encryption-based PVSSM. In this paper, we aim to present how Chaotic Encryption-based PVSSM is applied to color images. In order to assess the efficiency of this method, histogram analysis, data loss attack, salt-pepper noise attack, differential attack, chi-square analysis and correlation analysis tests were applied. The performance of this method has been evaluated according to NCPR, UACI, PSNR, SSIM and CQM. The proposed method achieved a good test values and showed better results compared to similar studies in literature

The Relationship between Physical Activity Levels and Psychological Resilience of University Students

The aim of this study is to investigate the relationship between physical activity levels and psychological resilience of university students. The survey model, which is one of the quantitative research types, has been used in the research. The research group consists of 1734 students - 725 (41.8%) males and 1009 (58.2%) females) - studying at Erzincan Binali Yıldırım University. Psychological Resilience Scale (PRS) and International Physical Activity Questionnaire (IPAQ) data was used as a collection tool. Descriptive statistics, chi-square test of independence, independent samples t-test, Anova (Tukey), correlation, and regression tests have been used in the analysis of the data. As a result of the study, it has been seen that physical activity levels of men were higher than women and that there was no significant difference between the groups' psychological resilience. And when body mass indexes were examined, it was observed that physical activity levels of those with thin index were higher than those with normal and overweight index. In addition, a significant low-level positive correlation has been found between the physical activity levels. Physical activity level is a variable that predicts psychological resilience level.The aim of this study is to investigate the relationship between physical activity levels and psychological resilience of university students. The survey model, which is one of the quantitative research types, has been used in the research. The research group consists of 1734 students - 725 (41.8%) males and 1009 (58.2%) females) - studying at Erzincan Binali Yıldırım University. Psychological Resilience Scale (PRS) and International Physical Activity Questionnaire (IPAQ) data was used as a collection tool. Descriptive statistics, chi-square test of independence, independent samples t-test, Anova (Tukey), correlation, and regression tests have been used in the analysis of the data. As a result of the study, it has been seen that physical activity levels of men were higher than women and that there was no significant difference between the groups' psychological resilience. And when body mass indexes were examined, it was observed that physical activity levels of those with thin index were higher than those with normal and overweight index. In addition, a significant low-level positive correlation has been found between the physical activity levels. Physical activity level is a variable that predicts psychological resilience level

The Relationship between Physical Activity Levels and Psychological Resilience of University Students

The aim of this study is to investigate the relationship between physical activity levels and psychological resilience of university students. The survey model, which is one of the quantitative research types, has been used in the research. The research group consists of 1734 students - 725 (41.8%) males and 1009 (58.2%) females) - studying at Erzincan Binali Yıldırım University. Psychological Resilience Scale (PRS) and International Physical Activity Questionnaire (IPAQ) data was used as a collection tool. Descriptive statistics, chi-square test of independence, independent samples t-test, Anova (Tukey), correlation, and regression tests have been used in the analysis of the data. As a result of the study, it has been seen that physical activity levels of men were higher than women and that there was no significant difference between the groups' psychological resilience. And when body mass indexes were examined, it was observed that physical activity levels of those with thin index were higher than those with normal and overweight index. In addition, a significant low-level positive correlation has been found between the physical activity levels. Physical activity level is a variable that predicts psychological resilience level.The aim of this study is to investigate the relationship between physical activity levels and psychological resilience of university students. The survey model, which is one of the quantitative research types, has been used in the research. The research group consists of 1734 students - 725 (41.8%) males and 1009 (58.2%) females) - studying at Erzincan Binali Yıldırım University. Psychological Resilience Scale (PRS) and International Physical Activity Questionnaire (IPAQ) data was used as a collection tool. Descriptive statistics, chi-square test of independence, independent samples t-test, Anova (Tukey), correlation, and regression tests have been used in the analysis of the data. As a result of the study, it has been seen that physical activity levels of men were higher than women and that there was no significant difference between the groups' psychological resilience. And when body mass indexes were examined, it was observed that physical activity levels of those with thin index were higher than those with normal and overweight index. In addition, a significant low-level positive correlation has been found between the physical activity levels. Physical activity level is a variable that predicts psychological resilience level

Stock Splits, A Survey

In this survey paper I summarize the literature's findings on the short-run and long-run effects of stock split announcements as well as what happens in the preceding and subsequent years around a stock split event. I also summarize how firm characteristics influence these results. Furthermore, I discuss the various theories regarding why splits occur and why stock return distributions change subsequent to split events. I specifically focus on the changes in the first and second moments of stock returns and analyze related theories such as optimal trading, optimal tick size, liquidity, and signaling. More importantly I present the pros and cons of each of these theories and discuss which of them are more plausible. I suggest that a combination of the several theories suggested in the literature can rationally explain the return distribution changes around stock splits. I conclude with suggestions for future research

The complexity of chemical signalling systems in lepidopteran males

Die Insekten gehören mit ihrer artenreichen Vielfalt zu der größten Gruppe der Gliederfüßler (Arthropoden). In ihrem Lebensumfeld spielt die chemische Kommunikation mit Signalsystemen als Mittel zum Informationsaustausch eine wichtige Rolle. Ziel der vorliegenden Arbeit sollte die Identifizierung und Synthese neuartiger natürlicher Verbindungen mit eventueller pheromonaler Wirkung aus verschiedenen Schmetterlingsarten sein. Dafür sollte das Duftprofil von Männchen und Weibchen (begattet / unbegattet) charakterisiert werden. Die Analyse der Duftdrüsenextrakte von den tropischen Passionsfaltern Heliconius sara, H. sapho, H. hewitsoni, H. pachinus, H. melpomene und H. numata erfolgte gaschromatographisch-massenspektrometrisch. Die Strukturen (9Z,13S)-Octadec-9-en-13-olid und (E)-Ocimen konnten dabei mit Hilfe von geeigneten Synthesen aus der Gruppe der Nicht-Puppenpaarer identifiziert werden. Bei (E)-Ocimen konnte eine antiaphrodisierende Wirkung festgestellt werden. Dabei markieren die Männchen die Weibchen bei der Begattung, so dass diese Weibchen für weitere Männchen unattraktiv werden. Das Programm Kelebek ermöglicht bei diesen Heliconiden-Arten die Analyse des Duftprofils für die Analyse des Stammbaums in Bezug ihres Paarungsverhaltens (Nicht-Puppenpaarer / Puppenpaarer). In Flügelextrakten des Großen Kohlweißlings (Pieris brassicae) konnte männchenspezifisch eine neue Verbindung, das Brassicalacton identifziert werden. Dies ist eine dem Ferrulacton analoge Struktur, welches in den Extrakten vom Kleinen Kohlweißling (Pieris rapae) vorkommt. In Biotests konnte gezeigt werden, dass es sich dabei um eine aphrodisierende Verbindung handelt, d.h. Männchen erfolgreicher bei der Begattung von Weibchen sind. Fütterungsexperimente mit markiertem 5,5,6,6,6-D-Mevalolacton beweisen, dass Ferrulacton vom Metabolismus des männlichen P. rapae über den Terpenbiosyntheseweg gebildet wird.Insects are diversified species and belong to the largest group of arthropods. For these invertebrates chemical communication using signalling systems plays an important role as a means of information exchange. The aim of this present work was the identification and synthesis of new natural compounds from various butterfly species with possible pheromonal activity. Therefore, the odour profile of males and females (mated / virgin) were characterized. The analysis of gland extracts of the passion-vine butterflies heliconius sara, h. sapho, h. hewitsoni, h. pachinus, h. melpomene and h. numata was performed using gaschromatographic and massspectrometric techniques. The structures of (9Z,13S)-octadec-9-en-13-olide and (E)-ocimene from the non-pupal mating group were identified using adequate syntheses. (E)-ocimene was also found to have an anti-aphrodisiac. Therefore males mark females during mating and turn them unattractive to other males. The program named Kelebek allows a detailed analysis of the odour profile of different heliconius species according to the tree of life related to their mating behavior (non-pupal mating / pupal mating). In male-specific wing extracts of the large cabbage butterfly (pieris brassicae) a new unknown compound, that we named brassicalactone was identified. This structure is anlogous to ferrulactone which is present in the extracts of the small cabbage butterfly (pieris rapae). Biological tests prove that ferrulactone is an aphrodisiac, which means that it renders males more successful in copulation with females. Feeding experiments with labelled 5,5,6,6,6-D-mevalolactone prove that ferrulactone was formed in metabolism of pieris rapae males by the terpene biosynthetic route

Cross-conjugated Pi-Electron Systems - On the Way to Ur-Indigo

Eines der Hauptziele der Arbeit bildet die Untersuchung des chemischen Potentials von [3]- und [4]Dendralen. Die in der Literatur beschriebenen Herstellungsweisen wurden reproduziert und das Potential der Kohlenwasserstoffe in Dien-transmissiven Diels-Alder-Reaktionen genutzt. Dabei wurde das schon zuvor hergestellte 3,5,8,8a-Tetrahydronaphthalin-1,2,6,7-tetracarbonsäuretetramethylester synthetisiert, das durch Dehydrierung aromatisiert wurde. Die Estergruppen konnten über den Alkohol in das entsprechende Tetrabromid umgewandelt werden. Durch Debromierung und Abfangexperimenten konnte der Naphthalingrundkörper linear und angular zum Benzo[a]anthracen-2,3,9,10-tetracarbonsäuretetramethylester anelliert werden. Die Chemie von [4]Dendralen wurde durch Addition von Acetylendicarbonsäuredimethylester untersucht. Das erhaltene 2:1-Addukt ist reaktionsträger als seine Vorstufe, kann aber dennoch zum 3:1-Addukt umgesetzt werden. Durch Aromatisierung wird ein hexasubstituiertes Phenanthren erhalten. Um den Beitrag der Kreuzkonjugation für Farbstoffe zu untersuchen, wurde im zweiten Teil der Arbeit versucht, das Ur-Indigo herzustellen. Hierzu wurden mehrere Synthesewege eingeschlagen. Die McMurry-Reaktion von 1-Isopropylidenindan-2-on liefert 5,5,11,11-Tetramethyl-5,6,11,12-tetrahydroindeno[1,2-b]fluoren. Die Umsetzung von 2,3,2´,3´-Tetrahydro-[2,2´]biindenyl-1,1´-dion mit dem Tebbe-Reagenz liefert das Cope-Umlagerungsprodukt 1,2-Bis[3-indenyl]ethan. Zur Untersuchung der Reaktivität von 1,2-Bis(3-indenyl)ethan wurde diese ins Dianion überführt und anschließend mit 1,2-Dibromethan versetzt. Es wird die Synthese der beiden diastereomeren Spirozwillinge Dispiro[inden-1,1´-cyclohexan-4´,1´´-syn-inden] und Dispiro[inden-1,1´-cyclohexan-4´,1´´-anti-inden] beobachtet.One of the aims of the work is the exploration of the chemical potential of [3]- and [4]dendralene. The literature reports have been reproduced and the potential of Hydrocarbon in diene-transmissive Diels-Alder-reaktions were employed. The 3,5,8,8a-tetrahydronaphthalene-1,2,6,7-tetracarboxylicacid tetramethylester has been synthesized and has been oxidized to the corresponding aromatic system. The estergroups has been transformed to the alcohol and then converted to the corresponding tetrabromide. Through debromination and trapping of the resulting ortho-quinodimethide, the naphthalene core could be anullated to linear and angular derivatives of benzoanthracene-2,3,9,10-tetracarboxylicacidtetramethylester. The chemistry of [4]dendralenes was explored through addition of acetylendicarboxylicacid dimethylester. The 2:1 Adduct is less reactive than the dendralene and therefore it was difficult to convert it to the 3:1 adduct. The hexasubstituted phenanthrene derivative was obtained after aromatisation. To understand the effect of cross-conjugation in dyes, the synthesis of Ur-Indigo [all-carbon indigo] was attempted. Many strategies were attempted. The McMurry-reaction of 1-isopropylideneindan-2-one afforded 5,5,11,11-tetramethyl-5,6,11,12-tetrahydroindeno[1,2-b]fluorine. The treatment of 2,3,2´,3´-tetrahydro-[2,2´]biindenyl-1,1´-dione with the Tebbe-reagent delivered the Cope-rearrangement product 1,2-bis[3-indenyl]ethane. To investigate the reactivity of 1,2-bis(3-indenyl)ethane it was tranformed into the Dianion and treated with 1,2-dibromethane. This resulted in the formation of a diastereomeric mixture of dispiro[indene-1,1´-cyclohexane-4´,1´´-syn-indene] and dispiro[indene-1,1´-cyclohexane-4´,1´´-anti-indene

Pyometra due to Pseudomonas aeruginosa

Pyometra is an unusual presentation of uterine infection, this condition is characterized by purulent fluid within the uterine cavity. In this report we describe pyometra due to Pseudomonas aeruginosa in a 90-year-old woman who presented with abdominal pain, nausea with emesis and diarrhea. She was evaluated at an outside emergency department and computed tomography (CT) revealed a large, complex, cystic mass measuring 9.2 cm (cm) in greatest diameter. Given her age, the diagnosis of malignancy was entertained. She was referred to gynecologic-oncologyservice for evaluation and underwent exploratory laparotomy with total abdominal hysterectomy and lysis of adhesions. Intraoperative findings were consistent with pyometra. Cultures ultimately grew Pseudomonas aeruginosa. She initiated on antibacterial therapy and was discharged to a rehabilitation facility

Essays in Pricing of Credit Risk in Bond and Equity Markets.

This work consists of two essays that investigate the pricing of credit risk in the equity and bond markets. The first essay, “Is there a Distress Risk Anomaly? Bond Spread as a Proxy for Default Risk,” investigates the pricing of default risk in the cross section of equity returns. The contribution of this paper to the literature is three-fold. First, the paper shows that the distress risk anomaly is an amalgamation of other anomalies and return relationships previously documented in the literature. Second, this is the first paper to use corporate bond spreads to measure the ex-ante probability of default risk. Third, contrary to previous findings, we show that default risk is not priced negatively in the cross section of equity returns. The second essay, “Corporate Reputation and Cost of Debt”, investigates the role a firm’s reputation plays in determining its cost of debt. We measure a company’s reputation using the annual ranking of “Most Admired Companies” published by Fortune magazine, which surveys industry experts on perceptions of firm quality along eight attributes. After controlling for credit risk and other known determinants of credit spreads, we find a robust inverse relationship between a firm’s reputation as measured by the Fortune survey and the credit spread on its bonds. We also find this effect to be greater for firms that are subject to greater information asymmetry. By explicitly accounting for an intangible element of credit risk, we substantially improve upon the existing literature which, relying on more tangible factors, concludes that a large component of credit spread variation remains unexplained. We also show that the Fortune reputation measure is a good ex ante predictor of corporate failure, improving upon standard measures used in the literature.Ph.D.Business AdministrationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89806/1/yildizha_1.pd

Is there a Distress Risk Anomaly? Pricing of Systematic Default Risk in the Cross Section of Equity Returns

The standard measures of distress risk ignore the fact that firm defaults are correlated and that some defaults are more likely to occur in bad times. We use risk premium computed from corporate credit spreads to measure a firm’s exposure to systematic variation in default risk. Unlike previously used measures that proxy for a firm’s physical probability of default, credit spreads proxy for a risk-adjusted default probability and thereby explicitly account for the non-diversifiable component of distress risk. In contrast to prior findings in the literature, we find that stocks that have higher credit risk premia, that is stocks with higher systematic default risk exposures, have higher expected equity returns which are largely explained by the market factor. We confirm the robustness of these results by using an alternative systematic default risk factor for firms that do not have bonds outstanding. Consistent with the theoretical result in George and Hwang (2010), we also show that firms react to increases in their systematic default risk exposures by reducing their leverage, leading to lower physical probabilities of distress. Our results show no evidence of firms with high systematic default risk exposure delivering anomalously low returns

Is there a Distress Risk Anomaly? Pricing of Systematic Default Risk in the Cross Section of Equity Returns

The standard measures of distress risk ignore the fact that firm defaults are correlated and that some defaults are more likely to occur in bad times. We use risk premium computed from corporate credit spreads to measure a firm’s exposure to systematic variation in default risk. Unlike previously used measures that proxy for a firm’s physical probability of default, credit spreads proxy for a risk-adjusted default probability and thereby explicitly account for the non-diversifiable component of distress risk. In contrast to prior findings in the literature, we find that stocks that have higher credit risk premia, that is stocks with higher systematic default risk exposures, have higher expected equity returns which are largely explained by the market factor. We confirm the robustness of these results by using an alternative systematic default risk factor for firms that do not have bonds outstanding. Consistent with the theoretical result in George and Hwang (2010), we also show that firms react to increases in their systematic default risk exposures by reducing their leverage, leading to lower physical probabilities of distress. Our results show no evidence of firms with high systematic default risk exposure delivering anomalously low returns