WorldCat Identities

Schoffer, Olaf 1974-

Overview
Works: 21 works in 48 publications in 2 languages and 696 library holdings
Roles: Author, Other, Contributor
Publication Timeline
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Most widely held works by Olaf Schoffer
Datenanalyse mit SAS statistische Verfahren und ihre grafischen Aspekte by Walter Krämer( )

10 editions published between 2005 and 2018 in German and held by 494 WorldCat member libraries worldwide

Das Programmpaket SAS hat sich im Lauf der Jahre als ein Standardwerkzeug zur statistischen Datenanalyse durchgesetzt. Der souveräne Umgang mit statistischen Methoden und deren praktischer Umsetzung in SAS bietet somit einen unschätzbaren Vorteil für die tägliche Arbeit aller Anwender, die in Studium oder Beruf mit der Analyse von Daten zu tun haben. Das vorliegende Buch erläutert alle gängigen statistischen Verfahren und deren Umsetzung als SAS-Programm. Es ist als Einführung in SAS geeignet, aber auch als Nachschlagewerk für Fortgeschrittene, mit deutlicher Betonung der grafischen Aspekte der statistischen Datenanalyse. Anleitungen zur Programmierung mit IML und Makros sowie hilfreiche Assistenten in SAS runden die Darstellung ab
Datenanalyse mit SAS statistische Verfahren und ihre grafischen Aspekte ; mit 68 Tabellen by Walter Krämer( Book )

2 editions published in 2005 in German and held by 127 WorldCat member libraries worldwide

Das Programmpaket sas hat sich im Verlauf der Jahre als ein Standardwerkzeug zur statistischen Datenanalyse durchgesetzt. Der souveräne Umgang mit statischen Methoden und deren praktischer Umsetzung in sas bietet somit einen unschätzbaren Vorteil für die tägliche Arbeit aller Anwender, die in Studium oder Beruf mit der Analyse von Daten zu tun haben. Das vorliegende Buch erläutert alle gängigen statistischen Verfahren und deren Umsetzung als sas- Programm. Es ist als Einführung, aber auch als Nachschlagewerk für Fortgeschrittene geeignet, mit deutlicher Betonung der grafischen Aspekte der statistischen Datenanalyse. Anleitungen zur Programmierung mit IML und Makros sowie hilfreiche Assistenten in sas runden die Darstellung ab. TOC:Einführung in die Benutzung von sas: Die Benutzerumgebung.- Das Hilfesystem.- Der DATA-Step.- Der PROC-Step. Präsentation und Aufbereitung von Ergebnissen: Aufbereitung von Textausgaben.- Erstellung von Grafiken. Grundlagen der Statistik: Deskriptive Verfahren.- Regression.- Inferenz. Spezialgebiete und Anwendungen: Stichprobenverfahren.- Versuchsplanung.- Nichtparametrische Verfahren.- Multivariate Verfahren.- Zeitreihenanalyse.- Ökonometrie. Besonderheiten von sas: Umgang mit Matrizen - IML.- Makroprogrammierung.- Assistenten.- Anhang: Lösungshinweise.- Spezielle Programme
Modellierung von Kapitalmarktrenditen mittels asymmetrischer GARCH-Modelle by Olaf Schoffer( )

5 editions published in 2003 in German and held by 26 WorldCat member libraries worldwide

Asymmetrie und langes Gedächtnis in Kapitalmarktdaten Modellierung von Renditen mit GARCH-Modellen by Olaf Schoffer( Book )

3 editions published between 2007 and 2011 in German and held by 6 WorldCat member libraries worldwide

Ist die Hebelwirkung der Grund für Asymmetrie in ARCH- und GARCH-Modellen? by Olaf Schoffer( Book )

3 editions published in 2000 in German and held by 6 WorldCat member libraries worldwide

HY-A-PARCH : a stationary A-PARCH model with long memory by Olaf Schoffer( )

3 editions published in 2003 in English and held by 5 WorldCat member libraries worldwide

The FI-A-PARCH process has been developed by Tse (1998) to model essential characteristics of financial market returns. However, due to the nonstationarity described by Níguez (2002) the process exhibits infinite conditional second moments and no statements about the autocovariance function can be derived. Thus, the new Hyperbolic A-PARCH model is considered, first introduced in Schoffer (2003). Subsequently the characteristics of this extension of the FI-A-PARCH process are inspected. It can be shown, that under certain parameter restrictions the intrinsic process as well as the process of conditional volatilities is stationary. Furthermore, for an asymmetric transformation of the conditional volatilities the presence of long memory is proven. Thus, the introduced model is able to reproduce the main characteristics of financial market returns such as volatility clustering, leptokurtosis, asymmetry and long memory
Tumour stage distribution and survival of malignant melanoma in Germany 2002-2011 by Olaf Schoffer( )

2 editions published in 2016 in English and held by 3 WorldCat member libraries worldwide

The cost-effectiveness of interventions targeting lifestyle change for the prevention of diabetes in a Swedish primary care and community based prevention program by Anne Neumann( )

2 editions published between 2016 and 2017 in English and held by 3 WorldCat member libraries worldwide

Background: Policymakers need to know the cost-effec-tiveness of interventions to prevent type 2 diabetes (T2D). The objective of this study was to estimate the cost-effectiveness of a T2D prevention initiative targeting weight reduction, increased physical activity and healthier diet in persons in pre-diabetic states by comparing a hypothetical intervention versus no intervention in a Swedish setting. Methods: A Markov model was used to study the cost-effectiveness of a T2D prevention program based on lifestyle change versus a control group where no prevention was applied. Analyses were done deterministically and probabilistically based on Monte Carlo simulation for six different scenarios defined by sex and age groups (30, 50, 70 years). Cost and quality adjusted life year (QALY) differences between no intervention and intervention and incremental cost-effectiveness ratios (ICERs) were estimated and visualized in cost-effectiveness planes (CE planes) and cost-effectiveness acceptability curves (CEA curves). Results: All ICERs were cost-effective and ranged from 3833 € /QALY gained (women, 30 years) to 9215 € /QALY gained (men, 70 years). The CEA curves showed that the probability of the intervention being cost-effective at the threshold value of 50,000 € per QALY gained was very high for all scenarios ranging from 85.0 to 91.1%. Discussion/conclusion: The prevention or the delay of the onset of T2D is feasible and cost-effective. A small investment in healthy lifestyle with change in physical activity and diet together with weight loss are very likely to be cost-effective
Tumour stage distribution and survival of malignant melanoma in Germany 2002-2011 by Olaf Schoffer( )

1 edition published in 2016 in English and held by 3 WorldCat member libraries worldwide

Trends in Incidence Rates during 1999-2008 and Prevalence in 2008 of Childhood Type 1 Diabetes Mellitus in GERMANY - Model-Based National Estimates by Ulrike Rothe( )

2 editions published in 2016 in English and held by 3 WorldCat member libraries worldwide

Risk equations for the development of worsened glucose status and type 2 diabetes mellitus in a Swedish intervention program by Anne Neumann( )

2 editions published in 2013 in English and held by 3 WorldCat member libraries worldwide

Background: Several studies investigated transitions and risk factors from impaired glucose tolerance (IGT) to type 2 diabetes mellitus (T2D). However, there is a lack of information on the probabilities to transit from normal glucose tolerance (NGT) to different pre-diabetic states and from these states to T2D. The objective of our study is to estimate these risk equations and to quantify the influence of single or combined risk factors on these transition probabilities. Methods: Individuals who participated in the VIP program twice, having the first examination at ages 30, 40 or 50 years of age between 1990 and 1999 and the second examination 10 years later were included in the analysis. Participants were grouped into five groups: NGT, impaired fasting glucose (IFG), IGT, IFG & IGT or T2D. Fourteen potential risk factors for the development of a worse glucose state (pre-diabetes or T2D) were investigated: sex, age, education, perceived health, triglyceride, blood pressure, BMI, smoking, physical activity, snus, alcohol, nutrition and family history. Analysis was conducted in two steps. Firstly, factor analysis was used to find candidate variables; and secondly, logistic regression was employed to quantify the influence of the candidate variables. Bootstrap estimations validated the models. Results: In total, 29 937 individuals were included in the analysis. Alcohol and perceived health were excluded due to the results of the factor analysis and the logistic regression respectively. Six risk equations indicating different impacts of different risk factors on the transition to a worse glucose state were estimated and validated. The impact of each risk factor depended on the starting or ending pre-diabetes state. High levels of triglyceride, hypertension and high BMI were the strongest risk factors to transit to a worsened glucose state. Conclusions: The equations could be used to identify individuals with increased risk to develop any of the three pre-diabetic states or T2D and to adapt prevention strategies
Datenanalyse mit SAS by Walter Krämer( Book )

3 editions published between 2005 and 2008 in German and held by 2 WorldCat member libraries worldwide

Ranking of the most relevant hospital inpatient diagnoses by age and diagnostic group based on DRG statistics in Germany by Olaf Schoffer( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Datenanalyse mit SAS Statistische Verfahren und ihre grafischen Aspekte by Walter Krämer( )

2 editions published between 2005 and 2008 in German and held by 2 WorldCat member libraries worldwide

Incidence trends of type 1 diabetes before and after the reunification in children up to 14 years of age in Saxony, Eastern Germany by Ulf Manuwald( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Evaluation of polymorphisms in angiogenesis-related genes as predictive and prognostic markers for sunitinib-treated metastatic renal cell carcinoma patients by Juana Dornbusch( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Trastuzumab and survival of patients with metastatic breast cancer by Karin Kast( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Health-related quality of life for pre-diabetic states and type 2 diabetes mellitus a cross-sectional study in Västerbotten Sweden by Anne Neumann( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

Background: Type 2 diabetes (T2D) decreases health-related quality of life, but there is a lack of information about the health status of people in pre-diabetic states. However, information on health utility weights (HUWs) for pre-diabetic states and T2D are essential to estimate the effect of prevention initiatives. We estimated and compared HUWs for healthy individuals, those with pre-diabetes and those with T2D in a Swedish population and evaluated the influence of age, sex, education and body mass index on HUWs. Methods: Participants of the Västerbotten Intervention Program, Sweden, between 2002 and 2012, who underwent an oral glucose tolerance test or indicated they had T2D and who filled in the Short Form-36 questionnaire (SF-36) were included. Individuals were categorized as healthy, being in any of three different pre-diabetic states, or as T2D. The pre-diabetic states are impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or a combination of both (IFG & IGT). The SF-6D index was used to convert SF-36 responses to HUWs. HUWswere stratified by age, sex, education and body mass index. Beta regression analyses were conducted to estimate the effect of multiple risk factors on the HUWs. Results: In total, 55 882 individuals were included in the analysis. The overall mean HUW was 0.764. The mean HUW of healthy individuals was 0.768, 0.759 for those with IFG, 0.746 for those with IGT, 0.745 for those with IFG & IGT, and 0.738 for those with T2D. In the overall model, all variables except underweight vs. normal weight were significantly associated with HUW. Younger age, male sex, and higher education were associated with increased HUW. Normal weight, or being overweight was associated with elevated HUW, while obesity was associated with lower HUW. Conclusions: Healthy individuals had higher HUWs than participants with T2D, while individuals with IFG, IGT or IFG & IGT had HUWs that ranged between those for NGT and T2D. Therefore, preventing the development of pre-diabetic states would improve health-related quality of life in addition to lowering the risk of developing T2D
 
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Datenanalyse mit SAS statistische Verfahren und ihre grafischen Aspekte ; mit 68 Tabellen Datenanalyse mit SAS
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Datenanalyse mit SAS statistische Verfahren und ihre grafischen Aspekte ; mit 68 TabellenDatenanalyse mit SAS
Alternative Names
Olaf Schoffer hulumtues

Olaf Schoffer wiskundige

Languages
German (29)

English (18)