Statistics and Probability Commons^™

To Hydrate Or Chlorinate: A Regression Analysis Of The Levels Of Chlorine In The Public Water Supply, Drew A. Doyle

HIM 1990-2015

Public water supplies contain disease-causing microorganisms in the water or distribution ducts. In order to kill off these pathogens, a disinfectant, such as chlorine, is added to the water. Chlorine is the most widely used disinfectant in all U.S. water treatment facilities. Chlorine is known to be one of the most powerful disinfectants to restrict harmful pathogens from reaching the consumer. In the interest of obtaining a better understanding of what variables affect the levels of chlorine in the water, this thesis will analyze a particular set of water samples randomly collected from locations in Orange County, Florida. Thirty water …

Correcting For Measurement Error In Latent Variables Used As Predictors, Lynne Steuerle Schofield

Mathematics & Statistics Faculty Works

This paper represents a methodological-substantive synergy. A new model, the Mixed Effects Structural Equations (MESE) model which combines structural equations modeling and item response theory, is introduced to attend to measurement error bias when using several latent variables as predictors in generalized linear models. The paper investigates racial and gender disparities in STEM retention in higher education. Using the MESE model with 1997 National Longitudinal Survey of Youth data, I find prior mathematics proficiency and personality have been previously underestimated in the STEM retention literature. Pre-college mathematics proficiency and personality explain large portions of the racial and gender gaps. The …

Objective Bayesian Analysis On The Quantile Regression, Shiyi Tu

All Dissertations

The dissertation consists of two distinct but related research projects. First of all, we study the Bayesian analysis on the two-piece location-scale models, which contain several well-known sub-distributions, such as the asymmetric Laplace distribution, the skewed normal distribution, and the skewed Student-t distribution. The use of two-piece location-scale models is an attractive method to model non-symmetric data. From a practical point of view, a prior with some objective information may be more reasonable due to the lack of prior information in many applied situations. It has been shown that several common used objective priors, such as the Jeffreys prior, result …

Stability Condition Of A Retrial Queueing System With Abandoned And Feedback Customers, Amina A. Bouchentouf, Abbes Rabhi, Lahcene Yahiaoui

Applications and Applied Mathematics: An International Journal (AAM)

This paper deals with the stability of a retrial queueing system with two orbits, abandoned and feedback customers. Two independent Poisson streams of customers arrive to the system, and flow into a single-server service system. An arriving one of type i; i = 1; 2, is handled by the server if it is free; otherwise, it is blocked and routed to a separate type-i retrial (orbit) queue that attempts to re-dispatch its jobs at its specific Poisson rate. The customer in the orbit either attempts service again after a random time or gives up receiving service and leaves the system …

An Optimal Reinsurance Contract From Insurer's And Reinsurer's Viewpoints, Ali P. Bazaz, Amir T. Payandeh Najafabadi

Applications and Applied Mathematics: An International Journal (AAM)

This article constructs two classes of appropriate reinsurance contracts from both an insurer’s and a reinsurer’s viewpoints. The first class, say C; has been constructed by minimizing the conditional tail expectation, say CTE, of an insurer’s random risk. Then an optimal reinsurance contract has been obtained by estimating the reinsurance’s random risk, using the Bayesian estimation method while the second class of reinsurance contracts, say C*; is obtained by minimizing a convex combination of the CTE of both the insurer’s and reinsurer’s random risks. These two approaches consider both the insurer’s and reinsurer’s viewpoints to establish an optimal reinsurance contract. …

An M/G/1 Queue With Server Breakdown And Multiple Working Vavation, S. P. Bala Murugan, K. Santhi

Applications and Applied Mathematics: An International Journal (AAM)

This paper deals with the steady state behavior of an M=G=1 multiple working vacation queue with server breakdown. The server works with different service times rather than completely stopping service during a vacation. Both service times in a vacation period and in a regular service period are assumed to be generally distributed random variables. The system may breakdown at random and repair time is arbitrary. Further, just after completion of a customer’s service the server may take a multiple working vacation. Supplementary variable technique is employed to find the probability generating function for the number of customers in the system. …

Simulations Of A New Response-Adaptive Biased Coin Design, Aleksandra Stein

Department of Statistics: Dissertations, Theses, and Student Research

Modern medical experiments accrue and treat patients--hence obtain treatment response data--throughout a trial. Designs which prospectively plan to modify patient allocation by leveraging accumulating data are response-adaptive randomization (RAR) designs. Many such designs attempt to balance the desire to bias assignment proportions towards a treatment which is performing better against the need to maintain randomization in the face of continued equipoise.

This dissertation consists of simulated investigations into frequentist and ethical properties of an new RAR biased coin design. Chapter 2 proposes a new adaptive design for phase III clinical trials, a modification of the 2001 Bandyopadhyay and Biswas biased …

Analysis Of Repairable M[X]/(G1,G2)/1 - Feedback Retrial G-Queue With Balking And Starting Failures Under At Most J Vacations, P. Rajadurai, M. C. Saravanarajan, V. M. Chandrasekaran

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we discuss the steady state analysis of a batch arrival feedback retrial queue with two types of service and negative customers. Any arriving batch of positive customers finds the server is free, one of the customers from the batch enters into the service area and the rest of them join into the orbit. The negative customer, arriving during the service time of a positive customer, will remove the positive customer in-service and the interrupted positive customer either enters into the orbit or leaves the system. If the orbit is empty at the service completion of each type …

Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa

Dissertations

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented.

The P-R model illustrates the decreasing …

Oriented Object Proposals, Shengfeng He, Rynson W. H. Lau

Research Collection School Of Computing and Information Systems

In this paper, we propose a new approach to generate oriented object proposals (OOPs) to reduce the detection error caused by various orientations of the object. To this end, we propose to efficiently locate object regions according to pixelwise object probability, rather than measuring the objectness from a set of sampled windows. We formulate the proposal generation problem as a generative probabilistic model such that object proposals of different shapes (i.e., sizes and orientations) can be produced by locating the local maximum likelihoods. The new approach has three main advantages. First, it helps the object detector handle objects of different …

Predicting Intraday Financial Market Dynamics Using Takens' Vectors; Incorporating Causality Testing And Machine Learning Techniques, Abubakar-Sadiq Bouda Abdulai

Electronic Theses and Dissertations

Traditional approaches to predicting financial market dynamics tend to be linear and stationary, whereas financial time series data is increasingly nonlinear and non-stationary. Lately, advances in dynamical systems theory have enabled the extraction of complex dynamics from time series data. These developments include theory of time delay embedding and phase space reconstruction of dynamical systems from a scalar time series. In this thesis, a time delay embedding approach for predicting intraday stock or stock index movement is developed. The approach combines methods of nonlinear time series analysis with those of causality testing, theory of dynamical systems and machine learning (artificial …

Poisson Versus Negative Binomial Regression In The Analysis Of Count Data, Barbie Ann L. Bugna

Dissertations

Commonly used tests for treatment effect in kx2 frequency data are Poisson regression, negative binomial regression, and Cochran-Mantel-Haentzel. In practice, Poisson regression or CMH is used as default, and NB regression is used only when there is reason to believe the data has overdispersion beyond what is expected of Poisson counts.

We show that the Poisson regression is sensitive to the Poisson assumption, and does not maintain its size in the presence of overdispersion. In particular, it tends to interpret overdispersion as significant treatment effect. Thus there is a need for a reliable pretest for the Poisson assumption. A commonly …

Rank Based Procedures For Ordered Alternative Models, Yuanyuan Shao

Dissertations

The ordered alternatives in a one-way layout with k ordered treatment levels are appropriate for many applications, especially in psychology and medicine. There is extensive literature in this area, and many parametric and nonparametric approaches have been introduced. Abelson-Tukey (AT) test is a frequently used parametric method. Its coefficients provide an ideal way of combining means for the purpose of detecting a monotonic relationship between the independent and dependent variables. The AT method, though, is not robust. Furthermore, our initial empirical studies show that it is not more powerful than the Jonckheere-Terpstra (JT) and the Hettmansperger- Norton (HN) nonparametric tests …

Calorimetry And Body Composition Research In Broilers And Broiler Breeders, Justina Victoria Caldas Cueva

Graduate Theses and Dissertations

Indirect calorimetry to study heat production (HP) and dual energy X-ray absorptiometry (DEXA) for body composition (BC) are powerful techniques to study the dynamics of energy and protein utilization in poultry. The first two chapters present the BC (dry matter, lean, protein, and fat, bone mineral, calcium and phosphorus) of modern broilers from 1 – 60 d of age analyzed by chemical analysis and DEXA. DEXA has been validated for precision, standardized for position, and equations and validations developed for chickens under two different feeding levels. These equations are unique to the machine and software in use. Research in broilers …

Probabilistic Graphical Modeling On Big Data, Ming-Hua Chung

Graduate Theses and Dissertations

The rise of Big Data in recent years brings many challenges to modern statistical analysis and modeling. In toxicogenomics, the advancement of high-throughput screening technologies facilitates the generation of massive amount of biological data, a big data phenomena in biomedical science. Yet, researchers still heavily rely on key word search and/or literature review to navigate the databases and analyses are often done in rather small-scale. As a result, the rich information of a database has not been fully utilized, particularly for the information embedded in the interactive nature between data points that are largely ignored and buried. For the past …

Disability Prevention Programs For Older People: Factors Associated With Medical And Nursing Care Costs, Takaaki Ikeda, Susumu Yanagawa, Kenichi Murakami, Toshiyuki Inoue, Takamasa Tsurumi

Kesmas

Penelitian ini bertujuan untuk mengklarifikasi faktor-faktor yang terkait dengan biaya medis dan perawatan lanjut usia (lansia) yang tinggal di panti sosial serta menyarankan program pencegahan disabilitas yang efektif. Total partisipan dalam penelitian ini adalah 83 orang (29 laki-laki dan 54 perempuan; usia rata-rata 81,2 ± 6,3 tahun) pada 1 November – 28 Desember 2014. Penelitian ini membandingkan biaya medis dan perawatan rata-rata per bulan dengan rata-rata nasional bagi yang berusia ≥ 65 tahun. Uji regresi logistik dilakukan untuk memeriksa keterkaitannya dengan biaya medis dan perawatan. Mereka yang pergi ke luar rumah ≥ 3 kali seminggu tiga kali lebih kecil kemungkinannya …

Pesticide Exposure, Behavior Of Farmer, And Activity Of Cholinesterase Enzyme In Blood Of Fertile Women Farmers, Deni Abdul Rahman, Zakianis Zakianis, Laila Fitria

Kesmas

Petani perempuan usia subur berisiko mengalami penurunan aktivitas kolinesterase akibat pajanan pestisida. Penelitian ini bertujuan untuk menganalisis hubungan antara pajanan pestisida dan perilaku pemajan terhadap aktivitas kolinesterase petani perempuan usia subur di Desa Kedunguter. Penelitian ini menggunakan desain potong lintang pada 94 petani perempuan usia subur tahun 2015. Pengumpulan data dilakukan secara observasi, wawancara, dan uji kolinesterase. Analisis data menggunakan uji kai kuadrat dan hasil analisis menunjukkan hubungan signifikan antara jenis pestisida, waktu kerja, penggunaan sarung tangan, perilaku mencuci tangan terhadap aktivitas kolinesterase petani perempuan usia subur. Hasil analisis pada penelitian ini menunjukkan bahwa variabel waktu kerja memiliki nilai odds …

The Use Of Earthworms And Household Organic Waste Composting Length Of Time, Abdul Khair, Lucky Herawati, Noraida Noraida, Munawar Raharja

Kesmas

Pengomposan dengan cacing tanah merupakan proses pembuatan kompos dengan melibatkan organisme makro cacing tanah. Kerja sama antara cacing tanah dengan mikroorganisme dapat memberi dampak pada proses penguraian yang dilakukan oleh mikroorganisme tersebut dibantu dengan keberadaan cacing tanah. Oleh karena bahan-bahan yang akan diurai oleh mikroorganisme telah diurai lebih dahulu oleh cacing, maka kerja mikroorganisme lebih efektif dan lebih cepat. Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan cacing tanah terhadap lama waktu pengomposan sampah organik dari rumah tangga dengan menggunakan desain penelitian eksperimen. Objek penelitian adalah seluruh sampah organik dari rumah tangga yang diambil secara acak pada satu rumah tangga. Variabel …

Riwayat Berat Badan Lahir Dengan Kejadian Stunting Pada Anak Usia Bawah Dua Tahun, Atikah Rahayu, Fahrini Yulidasari, Andini Octaviana Putri, Fauzie Rahman

Kesmas

Kabupaten Hulu Sungai Utara masih dihadapkan dengan permasalahan gizi pada anak bawah dua tahun (baduta). Salah satu masalah gizi hingga saat ini adalah stunting. Anak dengan riwayat berat badan lahir rendah (BBLR) merupakan salah satu faktor yang potensial memengaruhi pertumbuhan anak. Penelitian ini bertujuan untuk mengkaji risiko riwayat berat badan lahir dengan kejadian stunting pada anak baduta. Desain penelitian adalah potong lintang. Populasi penelitian ini merupakan ibu-ibu yang memiliki anak baduta dan besar sampel sejumlah 117 terdiri dari anak baduta. Pelaksanaan penelitian dilakukan selama tiga bulan pada bulan September – November 2014. Kategori BBLR jika riwayat berat badan lahir < 2.500 gram. Analisis data bivariat menggunakan uji kai kuadrat dan data multivariat menggunakan uji regresi logistik. Hasil analisis bivariat menunjukkan bahwa terdapat hubungan yang signifikan antara riwayat status BBLR (nilai p = 0,015) dengan stunting pada anak baduta. Berdasarkan hasil analisis multivariat, diperoleh bahwa BBLR merupakan faktor risiko yang paling dominan berhubungan dengan kejadian stunting. Anak dengan BBLR memiliki risiko 5,87 kali untuk mengalami stunting. Riwayat BBLR memiliki peranan penting dalam kejadian stunting anak baduta di wilayah Puskesmas Sungai Karias, Hulu Sungai Utara. North Hulu Sungai District is still facing nutrition problems among children under two years old. One of nutrition problems up to now is stunting. Child with low birthweight (LBW) record is one of potential factors influencing the growth of a child. This study aimed to assess any risk of LBW records with stunting incidence among children under two years old. This study used cross-sectional design. The population was mothers having children under two years old and samples amounted to 117 consisted of children under two years old. This study was conducted within three months on September – November 2014. Category of LBW was if birth weight records < 2,500 gram. Bivariate data analysis used chi-square test and multivariate data analysis used logistic regression test. The result of bivariate analysis showed a significant relation between LBW status records (p value = 0.015) with stunting incidence among children under two years old. Based on the result of multivariate analysis, LBW was the most dominating risk factor related to stunting incidence. Children with LBW had 5.87 times risk of suffering from stunting. LBW records take an important role in stunting incidence among children under two years old around Sungai Karias Primary Health Care area in North Hulu Sungai.

Penemuan Kasus Infeksi Kusta Subklinis Pada Anak Melalui Deteksi Kadar Antibodi (Igm) Anti Pgl-1, Arif Sujagat, Fardhiasih Dwi Astuti, Eva Muslimawati Saputri, Annisa Sani, Agil Dwi Prasetya

Kesmas

]Kusta merupakan penyakit menular kronis yang disebabkan Mycobacterium leprae. Indonesia menempati peringkat ketiga penyumbang kasus kusta terbanyak di dunia pada tahun 2012 – 2014. Kota Surabaya merupakan daerah endemis kusta. Penelitian ini bertujuan untuk deteksi dini kusta subklinis berdasarkan pengukuran kadar antibodi (IgM) anti PGL-1 dan mengetahui faktor-faktor yang berhubungan dengan kusta subklinis pada anak di Kota Surabaya. Penelitian analitik menggunakan desain potong lintang pada bulan April - Mei 2015. Populasi dilakukan penelitian adalah keluarga yang memiliki anggota penderita kusta. Sampel dipilih dengan teknik simple random sampling dan sebanyak 30 kepala keluarga terpilih melalui rapid school and village survey pada …