Machine Learning is the study of methods for programming computers to learn. Computers are applied to a wide range of tasks, and for most of these it is relatively easy for programmers to design and implement the necessary software. However, there are many tasks for which this is difficult or impossible. These can be divided into four general categories. First, there are problems for which there exist no human experts. For example, in modern automated manufacturing facilities, there is a need to predict machine failures before they occur by analyzing sensor readings. Because the machines are new, there are no human experts who can be interviewed by a programmer to provide the knowledge necessary to build a computer system. A machine learning system can study recorded data and subsequent machine failures and learn prediction rules. Second, there are problems where human experts exist, but where they are unable to explain their expertise. This is the case in many perceptual tasks, such as speech recognition, hand-writing recognition, and natural language understanding. Virtually all humans exhibit expert-level abilities on these tasks, but none of them can describe the detailed steps that they follow as they perform them. Fortunately, humans can provide machines with examples of the inputs and correct outputs for these tasks, so machine learning algorithms can learn to map the inputs to the outputs. Third, there are problems where phenomena are changing rapidly. In finance, for example, people would like to predict the future behavior of the stock market, of consumer purchases, or of exchange rates. These behaviors change frequently, so that even if a programmer could construct a good predictive computer program, it would need to be rewritten frequently. A learning program can relieve the programmer of this burden by constantly modifying and tuning a set of learned prediction rules. Fourth, there are applications that need to be customized for each computer user separately. Consider, for example, a program to filter unwanted electronic mail messages. Different users will need different filters. It is unreasonable to expect each user to program his or her own rules, and it is infeasible to provide every user with a software engineer to keep the rules up-to-date. A machine learning system can learn which mail messages the user rejects and maintain the filtering rules automatically. Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis. Statistics focuses on understanding the phenomena that have generated the data, often with the goal of testing different hypotheses about those phenomena. Data mining seeks to find patterns in the data that are understandable by people. Psychological studies of human learning aspire to understand the mechanisms underlying the various learning behaviors exhibited by people (concept learning, skill acquisition, strategy change, etc.).

Machine learning

Wireless indoor positioning systems have become very popular in recent years. These systems have been successfully used in many applications such as asset tracking and inventory management. This paper provides an overview of the existing wireless indoor positioning solutions and attempts to classify different techniques and systems. Three typical location estimation schemes of triangulation, scene analysis, and proximity are analyzed. We also discuss location fingerprinting in detail since it is used in most current system or solutions. We then examine a set of properties by which location systems are evaluated, and apply this evaluation method to survey a number of existing systems. Comprehensive performance comparisons including accuracy, precision, complexity, scalability, robustness, and cost are presented.

Survey of Wireless Indoor Positioning Techniques and Systems

Section I: Anatomy Surgical Anatomy of the Retroperitoneum, Kidneys, and Ureters Anatomy of the Lower Urinary Tract and Male Genitalia Section II: Clinical Decision Making Evaluation of the Urologic Patient: History, Physical Examination, and Urinalysis Urinary Tract Imaging: Basic Principles Outcomes Research Section III: Basics of Urologic Surgery Basic Instrumentation and Cystoscopy Basics of Laparoscopic Urologic Surgery Section IV: Infections and Inflammation Infections of the Urinary Tract-A. Schaeffer Inflammatory Conditions of the Male Genitourinary Tract Interstitial Cystitis and Related Disorders Sexually Transmitted and Associated Diseases Urological Implications of AIDS and Related Conditions Cutaneous Diseases of the External Genitalia Tuberculosis and Other Opportunistic Infections of the Genitourinary System Section V: Molecular and Cellular Biology Basic Principles of Immunology Molecular Genetics and Cancer Biology Tissue Engineering Perspectives for Reconstructive Surgery Section VI: Reproductive and Sexual Function Male Reproductive Physiology Male Infertility Surgical Management of Male Infertility Physiology of Erectile Dysfunction: Pathophysiology, Evaluation, Nonsurgical Management Epidemiology, Evaluation, and Nonsurgical Management of Erectile Dysfunction Prosthetic Surgery for Erectile Dysfunction Vascular Surgery for Erectile Dysfunction Peyronie's Disease Priapism Androgen Deficiency in the Aging Male Female Sexual Function and Dysfunction Section VII: Male Genitalia Neoplasms of the Testis Surgery of Testicular Tumors Tumors of the Penis Surgery of Penile and Urethral Carcinoma Surgery of the Penis and Urethra Surgery of the Scrotum and Seminal Vesicles Section VIII: Renal Physiology and Pathophysiology Renal Physiology and Pathophysiology Renovascular Hypertension Section IX: Upper Urinary Tract Obstruction and Trauma Pathophysiology of Obstruction Management of Upper Urinary Tract Obstruction Upper Urinary Tract Trauma Section X: Renal Failure and Transplantation Renal Transplantation Etiology, Pathogenesis, and Management of Renal Failure Section XI: Urinary Lithiasis and Endourology Urinary Lithiasis: Etiology, Epidemiology, and Pathophysiology Evaluation and Medical Management of Urinary Lithiasis Surgical Management of Upper Urinary Tract Calculi Ureteroscopy and Retrograde Ureteral Access Percutaneous Approaches to the Upper Urinary Tract Section XII: Neoplasms of the Upper Urinary Tract Renal Tumors Urothelial Tumors of the Upper Urinary Tract Urothelial Tumors of the Renal Pelvis and Ureter Open Surgery of the Kidney Laparoscopic Surgery of the Kidney Ablative Therapy for Renal Tumors Section XIII: The Adrenals Pathophysiology, Evaluation, and Medical Management of Adrenal Disorders Surgery of the Adrenals Section XIV: Urine Transport, Storage, and Emptying Physiology and Pharmacology of the Renal Pelvis and Ureter Physiology and Pharmacology of the Bladder and Urethra Pathophysiology, Categorization, and Management of Voiding Dysfunction Urodynamic and Video dynamic Evaluation of Voiding Dysfunction Neuromuscular Dysfunction of the Lower Urinary Tract Urinary Incontinence: Epidemiology, Pathophysiology, Evaluation, and Overview of Management The Overactive Bladder Pharmacologic Management of Storage and Emptying Failure Conservative Management of Urinary Incontinence: Behavioral and Pelvic Floor Therapy, Urethral and Pelvic Devices Electrical Stimulation and Neuromodulation in Storage and Emptying Failure Retropubic Suspension Surgery for Incontinence in Women Vaginal Reconstructive Surgery for Sphincteric Incontinence Pubovaginal Slings Tension-Free Vaginal Tape Procedures Injection Therapy for Urinary Incontinence Additional Treatment for Storage and Emptying Failure Geriatric Voiding Dysfunction and Urinary Incontinence Urinary Tract Fistulae Bladder and Urethral Diverticula Surgical Procedures for Sphincteric Incontinence in the Male: The Artificial Genitourinary Sphincter Perineal Sling Procedures Section XV: Bladder Lower Genitourinary Calculi and Trauma Urothelial Tumors of the Bladder Management of Superficial Bladder Cancer Management of Metastatic and Invasive Bladder Cancer Surgery of Bladder Cancer Laparoscopic Bladder Surgery Use of Intestinal Segments in Urinary Diversion Cutaneous Continent Urinary Diversion Orthotopic Urinary Diversion Genital and Lower Urinary Tract Trauma Lower Urinary Tract Calculi Section XVI: Prostate Molecular Biology, Endocrinology, and Physiology of the Prostate and Seminal Vesicles Etiology, Pathophysiology, and Epidemiology of Benign Prostatic Hyperplasia Natural History, Evaluation, and Nonsurgical Management of Benign Prostatic Hyperplasia Minimally Invasive and Endoscopic Management of Benign Prostatic Hyperplasia Retropubic and Superpubic Open Radical Prostatectomy Epidemiology, Etiology, and Prevention of Prostate Cancer Pathology of Prostatic Neoplasms Ultrasonography and Biopsy of the Prostate Tumor Markers in Prostate Cancer Early Detection, Diagnosis, and Staging of Prostate Cancer Definitive Therapy of Localized Prostate Cancer: Outcomes Expectant Management of Prostate Cancer Anatomic Retrograde Retropubic Prostatectomy Radical Perineal Prostatectomy Laparoscopic and Robotic Radical Prostatectomy and Pelvic Lymphadenectomy Radiation Therapy for Prostate Cancer Cryotherapy of Prostate Cancer Treatment of Locally Advanced Prostate Cancer Management of Rising Prostate-Specific Antigen after Definitive Therapy Hormonal Therapy for Prostate Cancer Management of Hormone-Resistant Prostate Cancer Section XVII: Pediatric Urology Normal and Anomalous Development of the Urinary Tract Renal Function in the Fetus Congenital Obstructive Uropathy Perinatal Urology Evaluation of Pediatric Urologic Patient Renal Disease in Childhood Urinary Tract Infections in Infants and Children Anomalies of the Kidney Renal Dysplasia and Cystic Disease of Kidney Anomalies and Surgery of the Ureteropelvic Junction Ectopic Ureter Vesicoureteral Reflux Prune-Belly Syndrome Exstrophy and Epispadias Complex Surgical Technique for One-Stage Exstrophy Reconstruction Bladder Anomalies in Children Posterior Urethral Valves and Other Urethral Anomalies Voiding Dysfunction in Children: Neurogenic and Non-neurogenic Urinary Tract Reconstruction Hypospadias Abnormalities of External Genitalia in Boys Abnormalities of Testis and Scrotum: Surgical Management Sexual Differentiation: Normal and Abnormal Surgical Management of Intersex Pediatric Oncology Pediatric Endourology and Laparoscopy Pediatric Genitourinary Trauma

Campbell-Walsh urology

Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods. † Correspondence: Chung-Ming Kuan, Institute of Economics, Academia Sinica, 128 Academia Road, Sec. 2, Taipei 115, Taiwan; ckuan@econ.sinica.edu.tw. †† I would like to express my sincere gratitude to the editor, Professor Steven Durlauf, for his patience and constructive comments on early drafts of this entry. I also thank Shih-Hsun Hsu and Yu-Lieh Huang for very helpful suggestions. The remaining errors are all mine.

Artificial neural networks

BACKGROUND Semen quality is taken as a surrogate measure of male fecundity in clinical andrology, male fertility, reproductive toxicology, epidemiology and pregnancy risk assessments. Reference intervals for values of semen parameters from a fertile population could provide data from which prognosis of fertility or diagnosis of infertility can be extrapolated. METHODS Semen samples from over 4500 men in 14 countries on four continents were obtained from retrospective and prospective analyses on fertile men, men of unknown fertility status and men selected as normozoospermic. Men whose partners had a time-to-pregnancy (TTP) of < or =12 months were chosen as individuals to provide reference distributions for semen parameters. Distributions were also generated for a population assumed to represent the general population. RESULTS The following one-sided lower reference limits, the fifth centiles (with 95th percent confidence intervals), were generated from men whose partners had TTP < or = 12 months: semen volume, 1.5 ml (1.4-1.7); total sperm number, 39 million per ejaculate (33-46); sperm concentration, 15 million per ml (12-16); vitality, 58% live (55-63); progressive motility, 32% (31-34); total (progressive + non-progressive) motility, 40% (38-42); morphologically normal forms, 4.0% (3.0-4.0). Semen quality of the reference population was superior to that of the men from the general population and normozoospermic men. CONCLUSIONS The data represent sound reference distributions of semen characteristics of fertile men in a number of countries. They provide an appropriate tool in conjunction with clinical data to evaluate a patient's semen quality and prospects for fertility.

/pdf/world-health-organization-reference-values-for-human-semen-3qu21s6tqf.pdf

World Health Organization reference values for human semen characteristics

We evaluated our experience to date with in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) after either cryopreserved sperm or sperm produced on the date of IVF/ICSI was used. We performed a retrospective statistical analysis of data derived from 188 women undergoing IVF/ICSI cycles using surgically retrieved sperm. A total of 318 IVF/ICSI treatment cycles with 3280 ova were performed using testicular sperm extraction (TESE, 304 cycles) or microsurgical epididymal sperm aspiration (MESA, 14 cycles). Sperm obtained at time of IVF/ICSI (fresh) or thawed cryopreserved sperm samples were used in 38 and 280 of the ICSI cycles, respectively. For IVF/ICSI cycles using both TESE and MESA sperm, the fertilization rate was 59.9% for cryopreserved sperm, and 53.6% when fresh sperm was used (chi2 P-alpha < .02, Cramer's 0.04). The fertilization rate for the TESE group alone was 60.0% for cryopreserved sperm and 55.1% for fresh sperm (chi2P-alpha = .075). Cohen effect size was computed at 0.03; yielding for P-beta = .8, 6597 ova would be required to demonstrate similarity between fresh and cryopreserved sperm in the TESE group. To demonstrate superiority of cryopreserved sperm in this group at a P-alpha significance level of .05, 7524 ova would be necessary. The pregnancy rate for the TESE group was 27.3% for cryopreserved sperm and 27% for fresh sperm. Further analysis of the pregnancy data in this group, using the methods described, yielded a chi2 P-alpha and power of 0.971 (effect size calculated at 0.002). While our fertilization rates for cryopreserved sperm are greater in analyses of surgically derived sperm, based on the 7 years required to obtain data on 3280 ova, full numerical resolution of the issue of whether cryopreserved sperm is superior or similar will not be available until approximately 2010. However, we believe these results, along with the similarity shown in pregnancy rates achieved with both types of sperm, clearly indicate that cryopreserved sperm is not inferior to fresh sperm.

Analysis of Outcomes of Cryopreserved Surgically Retrieved Sperm for IVF/ICSI

Introduction: IVF's 40th world birthday.

Re: The Effect of Age on the Expression of Apoptosis Biomarkers in Human Spermatozoa

Background. Perineal pressure due to bicycle riding has been associated with erectile dysfunction. We developed a novel method to measure the occlusive force exerted over the perineal arteries and determined perineal artery occlusion by a variety of seat designs. Methods. Doppler ultrasonography facilitated perineal artery localization and determination of the force required for perineal artery occlusion in 20 healthy men. Flexiforce(®) sensors were affixed over the proximal and distal aspects of the perineal arteries bilaterally. Individuals completed bicycle rides in the road- and stationary-settings with six distinct seat designs, including those with and without an anterior "nose." Results. The occlusion time proportion of the total ride time was calculated for each trial. The overall occlusion time proportion was 0.59 (95% CI [0.45-0.73]) across all seats and settings. The "no-nose" bicycle seat and the stationary-setting demonstrated significantly lower occlusion proportion times than the traditional nose bicycle seat and road-setting, respectively. However, all bicycle seats yielded an occlusion time proportion of 0.41 or greater. Discussion. Our method of real-time, non-invasive force measurement localized to the perineal arteries may be used to validate future bicycle seat design. It also underscores the significant risk of perineal artery insufficiency in men who are avid bicyclists. This risk may be minimized by using newer "no-nose" bicycle seats.

A novel method to determine perineal artery occlusion among male bicyclists

Re: Evaluation of diagnostic testis biopsy and the repetition of testicular sperm extraction surgeries in infertility patients.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Craig Niederberger

Author Tools

Chat about Author