Yasemin ŞİŞman - Academia.edu (original) (raw)

Papers by Yasemin ŞİŞman

Abstract The aim of this study is to analyze the role of experimental factors in the affine coord... more Abstract The aim of this study is to analyze the role of
experimental factors in the affine coordinate transformation
of cadastral maps using a 2^3 factorial design. The selected
experimental factors and their respective levels include amap
scale of 1/500–1/1,000, a number of common points 4 and
20, and the least square and least absolute value adjustment
method. The results were statistically analyzed using Student’s
t test, analysis of variance (ANOVA), and an F test
to define the important experimental factors and their levels.
A regression model that considers the significant main
and interaction effects is suggested. It was determined that
the affine coordinate transformation of cadastral maps was
affected by all of the selected experimental factors and the
interaction effects between themap scale and number of common
points. As results of the experiments, it is determined
that the factors levels for the reduced response variable are
the 1/500 map scale, 4 common points and the Least Square
Adjustment method.

In Turkey, cadastral work began during the Ottoman Empire. There are several kinds of cadastral m... more In Turkey, cadastral work began during the Ottoman Empire. There are several kinds of cadastral maps created by different production methods, coordinate system, base type, measurement, and calculation methods. These maps must be transformed into the Turkish national coordinate systems. Although there are many coordinate transformation methods, the affine transformation method is most commonly used in map transformation. The affine transformation solution consists of the adjustment of the obtained unique and best suitable parameters estimation. Although the least square (LS) adjustment method is in widespread use, there are some disadvantages in the determination of erroneous measurements. The least absolute value (LAV) determines the erroneous measurements and their effects on the other measurements results. In recent years, the total least square (TLS) method has been frequently used for estimation parameters. This study examines the transformation of non-digital cadastral maps in Turkey. After the evaluation of the current situation of cadastral maps, the affine transformation method is explained using adjustment methods. Finally, the success of affine transformation combined with the LS, LAV, and TLS methods is demonstrated by a numerical application. Thus, the most suitable adjustment method is obtained according to the results of the application. Keywords: affine coordinate transformation; adjustment method; the least absolute value method; cadastral work

Abstract The Global Positioning System (GPS) has become a popular sensing system for positioning ... more Abstract The Global Positioning System (GPS) has become a
popular sensing system for positioning because it is free and
always available and can be used in all weathers. However, the
accuracy of GPS is dependent on the measurement factors
selected by the surveyor. Therefore, the purpose of this research
is to determine the optimal factors of the GPS positioning
process. The selected process variables were measurement time
and duration, recording interval, and mask angle. To determine
the optimum conditions of these factors, a three-level Box–
Behnken design was utilized. The results indicated that the
optimum conditions of the experimental factors are 13 h as
measurement time, 21.77 min as the measurement duration,
22.43 s as the range interval, and 8° as the mask angle.

The aim of the study is to explain the parameter estimation methods and the regression analysis. ... more The aim of the study is to explain the parameter estimation methods and the regression analysis. The simple linear regression methods grouped according to the objective function are introduced. The numerical solution is achieved for the simple linear regression methods according to objective function of Least Squares and the Least Absolute Value adjustment methods. The success of the applied methods is analyzed using their objective function values.

Coordinate measurements inevitably contain outliers that affect the results of transformation. Co... more Coordinate measurements inevitably contain outliers that affect the results of transformation. Conventional methods based on the leasts squared method determine the outliers by minimizing the selected objective function. Fuzzy Logic can be used to analyze the outliers. In this study, several outlier detection methods are described and applied to a real case consisting of a triangulation network. Results show that for outlier detection methods are not as efficient as Fuzzy provides a non-iterative solution in contrast to conventional methods.

The best suitable values of unknown parameters are determined by adjustment of observations done ... more The best suitable values of unknown parameters are determined by adjustment of observations done more than the number of unknown parameter in applied sciences. Adjustment methods should determine the outlier, that inevitably exists in the observations, while doing estimation of the best appropriate parameter for the unknown parameters. The adjustment is made on the basis of an objective functions with the best parameter estimation from the mathematical model, written for the observations done more than the number of unknown parameters. The most applied methods used for adjustment are Least Square (LS), Least Absolute Values (LAV) and Total Least Square (TLS) Methods. Although there are many advantages of these methods, the LS method also has some disadvantages, such as more affected from gross observation errors in the observation and spread of gross error in other observations. The solution of LAV method and the results obtained with trial and error method for the parameter estimation are less affected by gross observation error; and this method is used successfully in removing the outlier. Besides, with these methods in recent years, the TLS method is used for the adjustment. In this method, the design matrix used for the solution is also erroneous and the residuals of observation and design matrix are calculated together in the solution. In this study, after three adjustment methods have been explained, the parameter estimation and outlier detection are made with using the application data. The success of adjustment methods for parameter estimation and outlier detection had been determined as well by examining the results of these methods.

The widespread geographic distribution of the Crimean-Congo hemorrhagic fever (CCHF) virus and it... more The widespread geographic distribution of the Crimean-Congo hemorrhagic fever (CCHF) virus and its ability to produce severe human disease with high mortality rates make the virus an important human pathogen. CCHF has a very wide geographic distribution, being endemic in more than 30 countries in Africa, central and southwestern Asia, the Middle East and Eastern Europe. CCHF virus-infected cases were first reported in Turkey in 2002 and a total of 3135 confirmed cases were reported between 2002 and 2008. This increase in Turkey may be attributed to the country lying on the migratory path between Africa and Europe, changes in climatic factors, and environmental factors.This study was intended to provide the risk area and spatial distribution map and, patients diagnosed with CCHF at hospitals in the Turkish province of Samsun and at the Ondokuz Mayis University Medical Faculty Hospital (OMUMFH) between 01 January, 2004, and 31 December, 2008, by establishing their domicile addresses, and to produce an epidemiological risk map for the disease using Geographical Information Systems.

Consistent and outlier measurements coexist in the measurement group in the applicable sciences. ... more Consistent and outlier measurements coexist in the measurement group in the applicable sciences. The adjustment calculus, is made to obtain the nearest solution for real and is detached measurements as consistent or outlier. Various methods are being used in order to determine the outlier measurements in the measurement group. The conventional solution methods and making solutions in accordance with the Least Squares Method, determine the outlier measurements, however, they have some disadvantages like the fact that the corrections are much effected by the errors, they spread the measurement errors to other corrections of measurements, not more than one outlier measurement can be determined in each solution step and that they remove the measurement which is determined to be outlier from the measurement group depending on the structure of the aim function. These disadvantages of the conventional solution method have brought out the search for other methods in order to determine the outlier measurement groups. The robust estimation method presents a solution method compared to the aim function being less affected by the measurement errors. The robust estimation method makes an iterative solution by redetermining the measurement weights according to weight function gained from the aim function being less affected by measurement errors in the solution made in accordance with the Least Squares Method. A few different estimation methods are being used in redetermining the measurement weights. In this study, the methods used for redetermining the measurement weights are explained by expressing the reasons to use the robust estimation methods in the outlier measurements analysis. In order to match the theoretically explained methods, an application has been made by using the real network data and the applicability of these methods has been searched.

Konum belirleme baraj, köprü, tren yolu, kanalizasyon ve boru hattı projeleri, deformasyon ve kab... more Konum belirleme baraj, köprü, tren yolu, kanalizasyon ve boru hattı projeleri, deformasyon ve kabuk hareketlerinin ölçümünde çok sıklıkla kullanılmaktadır. Çevresel faktörler ve ölçücü tarafından belirlenen ölçme seçenekleri GNNS ile konum belirlemenin doğruluğunu etkiler. Deney tasarımı ile farklı faktörlerin sonuç değişken üzerindeki etkileri araştırılır. Deney tasarımı yöntemlerinden biri de Full Faktöriyel Dizayndır. Bu çalışmanın amacı GNNS ile konum belirlemede seçilen faktörlerin etkilerini belirlemektir. Bu amaçla yapılan uygulamada sonuç değişkeni olarak GNNS ile konum belirlemenin karesel ortalama hatası, faktörler olarak da ölçü zamanı, ölçü süresi ve uydu yükseklik açısı seçilmiştir. Bu işlem için 2 3 faktöriyel deney tasarlanmış ve Ondokuz Mayıs Üniversitesi Kampüs alanında oluşturulan kontrol ağının ölçüleri kullanılmıştır. Yapılan çalışma ile seçilen faktörlerin (+1) seviyelerinin sonuç değişkenini azalttığı görülmüştür ve GNNS ile konum belirlemede ölçü faktörlerinin çalışmanın amacına göre seçilerek deney tasarımı yöntemi ile analiz edilebileceği sonucuna varılmıştır.

Acta Geodaetica et Geophysica, 2014

Your article is protected by copyright and all rights are held exclusively by Akadémiai Kiadó. Th... more Your article is protected by copyright and all rights are held exclusively by Akadémiai Kiadó. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

… Journal of the Physical Sciences, IJPS, 2010

L 2 -norm, also known as the least squares method was widely used in the adjustment calculus. The... more L 2 -norm, also known as the least squares method was widely used in the adjustment calculus. The weaknesses of the least squares method were the effect of gross measurements error on the solution and the disturbance and absorbance of gross error on the solution. L 1 -norm, also known as the least absolute values method, was affected by almost none or very little from gross error. Therefore L 1 -norm method, used for parameters estimation in some special case, has been successfully used for outlier measurements detection. In this study, the L 1 and L 2 -norm adjustment methods have been taken relatively to each other's advantages and disadvantages and the numerical application of the twodimensional similarity coordinate transformation were made and the results of both methods are discussed.

Abstract The aim of this study is to analyze the role of experimental factors in the affine coord... more Abstract The aim of this study is to analyze the role of
experimental factors in the affine coordinate transformation
of cadastral maps using a 2^3 factorial design. The selected
experimental factors and their respective levels include amap
scale of 1/500–1/1,000, a number of common points 4 and
20, and the least square and least absolute value adjustment
method. The results were statistically analyzed using Student’s
t test, analysis of variance (ANOVA), and an F test
to define the important experimental factors and their levels.
A regression model that considers the significant main
and interaction effects is suggested. It was determined that
the affine coordinate transformation of cadastral maps was
affected by all of the selected experimental factors and the
interaction effects between themap scale and number of common
points. As results of the experiments, it is determined
that the factors levels for the reduced response variable are
the 1/500 map scale, 4 common points and the Least Square
Adjustment method.

In Turkey, cadastral work began during the Ottoman Empire. There are several kinds of cadastral m... more In Turkey, cadastral work began during the Ottoman Empire. There are several kinds of cadastral maps created by different production methods, coordinate system, base type, measurement, and calculation methods. These maps must be transformed into the Turkish national coordinate systems. Although there are many coordinate transformation methods, the affine transformation method is most commonly used in map transformation. The affine transformation solution consists of the adjustment of the obtained unique and best suitable parameters estimation. Although the least square (LS) adjustment method is in widespread use, there are some disadvantages in the determination of erroneous measurements. The least absolute value (LAV) determines the erroneous measurements and their effects on the other measurements results. In recent years, the total least square (TLS) method has been frequently used for estimation parameters. This study examines the transformation of non-digital cadastral maps in Turkey. After the evaluation of the current situation of cadastral maps, the affine transformation method is explained using adjustment methods. Finally, the success of affine transformation combined with the LS, LAV, and TLS methods is demonstrated by a numerical application. Thus, the most suitable adjustment method is obtained according to the results of the application. Keywords: affine coordinate transformation; adjustment method; the least absolute value method; cadastral work

Abstract The Global Positioning System (GPS) has become a popular sensing system for positioning ... more Abstract The Global Positioning System (GPS) has become a
popular sensing system for positioning because it is free and
always available and can be used in all weathers. However, the
accuracy of GPS is dependent on the measurement factors
selected by the surveyor. Therefore, the purpose of this research
is to determine the optimal factors of the GPS positioning
process. The selected process variables were measurement time
and duration, recording interval, and mask angle. To determine
the optimum conditions of these factors, a three-level Box–
Behnken design was utilized. The results indicated that the
optimum conditions of the experimental factors are 13 h as
measurement time, 21.77 min as the measurement duration,
22.43 s as the range interval, and 8° as the mask angle.

The aim of the study is to explain the parameter estimation methods and the regression analysis. ... more The aim of the study is to explain the parameter estimation methods and the regression analysis. The simple linear regression methods grouped according to the objective function are introduced. The numerical solution is achieved for the simple linear regression methods according to objective function of Least Squares and the Least Absolute Value adjustment methods. The success of the applied methods is analyzed using their objective function values.

Coordinate measurements inevitably contain outliers that affect the results of transformation. Co... more Coordinate measurements inevitably contain outliers that affect the results of transformation. Conventional methods based on the leasts squared method determine the outliers by minimizing the selected objective function. Fuzzy Logic can be used to analyze the outliers. In this study, several outlier detection methods are described and applied to a real case consisting of a triangulation network. Results show that for outlier detection methods are not as efficient as Fuzzy provides a non-iterative solution in contrast to conventional methods.

The best suitable values of unknown parameters are determined by adjustment of observations done ... more The best suitable values of unknown parameters are determined by adjustment of observations done more than the number of unknown parameter in applied sciences. Adjustment methods should determine the outlier, that inevitably exists in the observations, while doing estimation of the best appropriate parameter for the unknown parameters. The adjustment is made on the basis of an objective functions with the best parameter estimation from the mathematical model, written for the observations done more than the number of unknown parameters. The most applied methods used for adjustment are Least Square (LS), Least Absolute Values (LAV) and Total Least Square (TLS) Methods. Although there are many advantages of these methods, the LS method also has some disadvantages, such as more affected from gross observation errors in the observation and spread of gross error in other observations. The solution of LAV method and the results obtained with trial and error method for the parameter estimation are less affected by gross observation error; and this method is used successfully in removing the outlier. Besides, with these methods in recent years, the TLS method is used for the adjustment. In this method, the design matrix used for the solution is also erroneous and the residuals of observation and design matrix are calculated together in the solution. In this study, after three adjustment methods have been explained, the parameter estimation and outlier detection are made with using the application data. The success of adjustment methods for parameter estimation and outlier detection had been determined as well by examining the results of these methods.

The widespread geographic distribution of the Crimean-Congo hemorrhagic fever (CCHF) virus and it... more The widespread geographic distribution of the Crimean-Congo hemorrhagic fever (CCHF) virus and its ability to produce severe human disease with high mortality rates make the virus an important human pathogen. CCHF has a very wide geographic distribution, being endemic in more than 30 countries in Africa, central and southwestern Asia, the Middle East and Eastern Europe. CCHF virus-infected cases were first reported in Turkey in 2002 and a total of 3135 confirmed cases were reported between 2002 and 2008. This increase in Turkey may be attributed to the country lying on the migratory path between Africa and Europe, changes in climatic factors, and environmental factors.This study was intended to provide the risk area and spatial distribution map and, patients diagnosed with CCHF at hospitals in the Turkish province of Samsun and at the Ondokuz Mayis University Medical Faculty Hospital (OMUMFH) between 01 January, 2004, and 31 December, 2008, by establishing their domicile addresses, and to produce an epidemiological risk map for the disease using Geographical Information Systems.

Consistent and outlier measurements coexist in the measurement group in the applicable sciences. ... more Consistent and outlier measurements coexist in the measurement group in the applicable sciences. The adjustment calculus, is made to obtain the nearest solution for real and is detached measurements as consistent or outlier. Various methods are being used in order to determine the outlier measurements in the measurement group. The conventional solution methods and making solutions in accordance with the Least Squares Method, determine the outlier measurements, however, they have some disadvantages like the fact that the corrections are much effected by the errors, they spread the measurement errors to other corrections of measurements, not more than one outlier measurement can be determined in each solution step and that they remove the measurement which is determined to be outlier from the measurement group depending on the structure of the aim function. These disadvantages of the conventional solution method have brought out the search for other methods in order to determine the outlier measurement groups. The robust estimation method presents a solution method compared to the aim function being less affected by the measurement errors. The robust estimation method makes an iterative solution by redetermining the measurement weights according to weight function gained from the aim function being less affected by measurement errors in the solution made in accordance with the Least Squares Method. A few different estimation methods are being used in redetermining the measurement weights. In this study, the methods used for redetermining the measurement weights are explained by expressing the reasons to use the robust estimation methods in the outlier measurements analysis. In order to match the theoretically explained methods, an application has been made by using the real network data and the applicability of these methods has been searched.

Konum belirleme baraj, köprü, tren yolu, kanalizasyon ve boru hattı projeleri, deformasyon ve kab... more Konum belirleme baraj, köprü, tren yolu, kanalizasyon ve boru hattı projeleri, deformasyon ve kabuk hareketlerinin ölçümünde çok sıklıkla kullanılmaktadır. Çevresel faktörler ve ölçücü tarafından belirlenen ölçme seçenekleri GNNS ile konum belirlemenin doğruluğunu etkiler. Deney tasarımı ile farklı faktörlerin sonuç değişken üzerindeki etkileri araştırılır. Deney tasarımı yöntemlerinden biri de Full Faktöriyel Dizayndır. Bu çalışmanın amacı GNNS ile konum belirlemede seçilen faktörlerin etkilerini belirlemektir. Bu amaçla yapılan uygulamada sonuç değişkeni olarak GNNS ile konum belirlemenin karesel ortalama hatası, faktörler olarak da ölçü zamanı, ölçü süresi ve uydu yükseklik açısı seçilmiştir. Bu işlem için 2 3 faktöriyel deney tasarlanmış ve Ondokuz Mayıs Üniversitesi Kampüs alanında oluşturulan kontrol ağının ölçüleri kullanılmıştır. Yapılan çalışma ile seçilen faktörlerin (+1) seviyelerinin sonuç değişkenini azalttığı görülmüştür ve GNNS ile konum belirlemede ölçü faktörlerinin çalışmanın amacına göre seçilerek deney tasarımı yöntemi ile analiz edilebileceği sonucuna varılmıştır.

Acta Geodaetica et Geophysica, 2014

Your article is protected by copyright and all rights are held exclusively by Akadémiai Kiadó. Th... more Your article is protected by copyright and all rights are held exclusively by Akadémiai Kiadó. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

… Journal of the Physical Sciences, IJPS, 2010

L 2 -norm, also known as the least squares method was widely used in the adjustment calculus. The... more L 2 -norm, also known as the least squares method was widely used in the adjustment calculus. The weaknesses of the least squares method were the effect of gross measurements error on the solution and the disturbance and absorbance of gross error on the solution. L 1 -norm, also known as the least absolute values method, was affected by almost none or very little from gross error. Therefore L 1 -norm method, used for parameters estimation in some special case, has been successfully used for outlier measurements detection. In this study, the L 1 and L 2 -norm adjustment methods have been taken relatively to each other's advantages and disadvantages and the numerical application of the twodimensional similarity coordinate transformation were made and the results of both methods are discussed.