Data-driven methods for personalized product recommendation systems

Thesis: Ph. D., Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2018.Cataloged from PDF version of thesis.Includes bibliographical references.The online market has expanded tremendously over the past two decades across all industries ranging from retail to travel. This trend has resulted in the growing availability of information regarding consumer preferences and purchase behavior, sparking the development of increasingly more sophisticated product recommendation systems. Thus, a competitive edge in this rapidly growing sector could be worth up to millions of dollars in revenue for an online seller. Motivated by this increasingly prevalent problem, we propose an innovative model that selects, prices and recommends a personalized bundle of products to an online consumer. This model captures the trade-off between myopic profit maximization and inventory management, while selecting relevant products from consumer preferences. We develop two classes of approximation algorithms that run efficiently in real-time and provide analytical guarantees on their performance. We present practical applications through two case studies using: (i) point-of-sale transaction data from a large U.S. e-tailer, and, (ii) ticket transaction data from a premier global airline. The results demonstrate that our approaches result in significant improvements on the order of 3-7% lifts in expected revenue over current industry practices. We then extend this model to the setting in which consumer demand is subject to uncertainty. We address this challenge using dynamic learning and then improve upon it with robust optimization. We first frame our learning model as a contextual nonlinear multi-armed bandit problem and develop an approximation algorithm to solve it in real-time. We provide analytical guarantees on the asymptotic behavior of this algorithm's regret, showing that with high probability it is on the order of O([square root of] T). Our computational studies demonstrate this algorithm's tractability across various numbers of products, consumer features, and demand functions, and illustrate how it significantly out performs benchmark strategies. Given that demand estimates inherently contain error, we next consider a robust optimization approach under row-wise demand uncertainty. We define the robust counterparts under both polynomial and ellipsoidal uncertainty sets. Computational analysis shows that robust optimization is critical in highly constrained inventory settings, however the price of robustness drastically grows as a result of pricing strategies if the level of conservatism is too high.by Anna Papush.Ph. D

Groundfish overfishing, diatom decline, and the marine silica cycle : lessons from Saanich Inlet, Canada, and the Baltic Sea cod crash

Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 23 (2009): GB4032, doi:10.1029/2008GB003416.In this study, we link groundfish activity to the marine silica cycle and suggest that the drastic mid-1980s crash of the Baltic Sea cod (Gadus morhua) population triggered a cascade of events leading to decrease in dissolved silica (DSi) and diatom abundance in the water. We suggest that this seemingly unrelated sequence of events was caused by a marked decline in sediment resuspension associated with reduced groundfish activity resulting from the cod crash. In a study in Saanich Inlet, British Columbia, Canada, we discovered that, by resuspending bottom sediments, groundfish triple DSi fluxes from the sediments and reduce silica accumulation therein. Using these findings and the available oceanographic and environmental data from the Baltic Sea, we estimate that overfishing and recruitment failure of Baltic cod reduced by 20% the DSi supply from bottom sediments to the surface water leading to a decline in the diatom population in the Baltic Sea. The major importance of the marginal ocean in the marine silica cycle and the associated high population density of groundfish suggest that groundfish play a major role in the silica cycle. We postulate that dwindling groundfish populations caused by anthropogenic perturbations, e.g., overfishing and bottom water anoxia, may cause shifts in marine phytoplankton communities.We acknowledge the VENUS Project, University of Victoria, for supporting the ship and submersible time for field experiments and USGS, CMGP, for support to J.C. Additional funding from NSERC Canada and from the Canada Research Chairs Foundation to V.T.; a Rothschild fellowship to G.Y.; and a Yohay Ben-Nun fellowship and Moshe Shilo Center for Marine Biogeochemistry fund to T.K. are also acknowledged

Ekonometrická analýza crowdfundingových kampaní

Abstract Crowdfunding is one of the most interesting and inspiring topics of recent times and is only getting more popular as time goes by. Studying it allows you to better understand the incentive that arouse public interest, make assumptions about how information is transmitted and wonder as far is possible to predict the behavior of the crowd. Not surprisingly, there are more and more studies exploring the subject. This paper provides a brief overview of articles on the topic of crowdfunding, mainly in terms of the factors that affect the success of the project. In the practical part of the current bachelor thesis, there is a study of the key success factors of the project based on the data of the two most famous reward-based crowdfunding platforms Kickstarter and Indiegogo. The practical part of this thesis is building Lenear Regression and Logistic Regression models using the datasets from the above mentioned platforms. Mentioned models can predict the success of the project to a certain extent.Abstrakt Crowdfunding je jedním z nejzajímavějších a nejinspirativnějších témat poslední doby a postupem času se stává stále populárnějším. Jeho studium umožňuje lépe porozumět podnětům, které vzbuzují zájem veřejnosti, vytvářet předpoklady o způsobu přenosu informací a přemýšlet, nakolik je možné předvídat chování davu. Není divu, že studií zkoumajících toto téma přibývá. Tento článek přináší stručný přehled článků na téma crowdfundingu, především z hlediska faktorů, které ovlivňují úspěšnost projektu. V praktické části je uvedena studie klíčových faktorů úspěchu projektu na základě údajů dvou nejznámějších crowdfundingových platforem Kikstarter a Indiegogo. Následně je provedena konstrukce modelů Lineární regrese a Logistické regrese, které lze do určité míry použít k předpovědi úspěšnosti projektu

Kisels kretslopp i Östersjön : Trender och budget av löst kisel

The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. The results provide new information about spatial and temporal changes in DSi concentrations and nutrient ratios for the period 1970-2001 as well as during the 20th century. For the period 1970-2001, the declining DSi trends were found at the majority of monitoring stations all over the Baltic Sea. This decrease is assumed to be mainly due to the ongoing eutrophication. It is supported by the increasing trends of inorganic nitrogen and phosphorus. The trends have implications for the nutrient ratios, DSi:DIN and DSi:DIP, which are important indicators of the state of an ecosystem. The long-term retrospective DSi budget has shown that the DSi concentrations before major hydrological alterations and eutrophication were about twice the present ones. This decrease is related to both eutrophication and anthropogenic perturbations in the catchment. The occurrence of DSi concentrations close to the potentially limiting levels has been also analysed. While DSi concentrations are still high in the northern regions of the Baltic, other areas may be at risk of developing Si limitation if the decrease in DSi concentrations persists. The results depict the Baltic Sea journey from being water body with DSi levels sufficient to support diatom production to one that may experience Si limitation and its adverse ecological consequences.Löst kisel (DSi) har en viktig roll för tillväxten av en stor grupp av primärproducenter – kiselalger, och därmed även påverkar hela den akvatiska näringskedjan. Denna avhandling bidrar till en ökad förståelse av förändringarna i DSi kretsloppet i Östersjön. Resultaten tillhandahåller ny information om rumsliga och tidsmässiga förändringar i DSi koncentrationer såväl för perioden 1970-2001 som för hela 1900-talet. För perioden 1970-2001 återfanns minskade DSi koncentrationer på mätstationer över hela Östersjön. Minskningen antas främst bero på den pågående övergödningen. Detta antagande stöds av stigande halter av oorganiskt kväve och fosfor. Sammantaget har dessa trender en inverkan på ekosystemets tillstånd och näringsämnenas kvoter, DSi: DIN och DSi: DIP. Ur ett längre tidsperspektiv kan man se att innan övergödningen och de stora hydrologiska ombildningar i Östersjöområdet var DSi koncentrationerna ungefär dubbelt så höga som idag. Dagens förekomst av DSi koncentrationer som ligger nära de potentiellt begränsande nivåerna har också analyserats. DSi koncentrationerna är fortfarande höga i norra delar av Östersjön, men är i andra områden i riskzonen för att utveckla Si begränsning om minskningen av DSi koncentrationer fortsätter. Resultaten skildrar Östersjöns resa från att vara ett havsområde med DSi halter som är tillräckliga för att understödja kiselalgernas produktion till ett sådant som kan uppleva Si begränsning och dess negativa ekologiska konsekvenser

Kisels kretslopp i Östersjön : Trender och budget av löst kisel

The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. The results provide new information about spatial and temporal changes in DSi concentrations and nutrient ratios for the period 1970-2001 as well as during the 20th century. For the period 1970-2001, the declining DSi trends were found at the majority of monitoring stations all over the Baltic Sea. This decrease is assumed to be mainly due to the ongoing eutrophication. It is supported by the increasing trends of inorganic nitrogen and phosphorus. The trends have implications for the nutrient ratios, DSi:DIN and DSi:DIP, which are important indicators of the state of an ecosystem. The long-term retrospective DSi budget has shown that the DSi concentrations before major hydrological alterations and eutrophication were about twice the present ones. This decrease is related to both eutrophication and anthropogenic perturbations in the catchment. The occurrence of DSi concentrations close to the potentially limiting levels has been also analysed. While DSi concentrations are still high in the northern regions of the Baltic, other areas may be at risk of developing Si limitation if the decrease in DSi concentrations persists. The results depict the Baltic Sea journey from being water body with DSi levels sufficient to support diatom production to one that may experience Si limitation and its adverse ecological consequences.Löst kisel (DSi) har en viktig roll för tillväxten av en stor grupp av primärproducenter – kiselalger, och därmed även påverkar hela den akvatiska näringskedjan. Denna avhandling bidrar till en ökad förståelse av förändringarna i DSi kretsloppet i Östersjön. Resultaten tillhandahåller ny information om rumsliga och tidsmässiga förändringar i DSi koncentrationer såväl för perioden 1970-2001 som för hela 1900-talet. För perioden 1970-2001 återfanns minskade DSi koncentrationer på mätstationer över hela Östersjön. Minskningen antas främst bero på den pågående övergödningen. Detta antagande stöds av stigande halter av oorganiskt kväve och fosfor. Sammantaget har dessa trender en inverkan på ekosystemets tillstånd och näringsämnenas kvoter, DSi: DIN och DSi: DIP. Ur ett längre tidsperspektiv kan man se att innan övergödningen och de stora hydrologiska ombildningar i Östersjöområdet var DSi koncentrationerna ungefär dubbelt så höga som idag. Dagens förekomst av DSi koncentrationer som ligger nära de potentiellt begränsande nivåerna har också analyserats. DSi koncentrationerna är fortfarande höga i norra delar av Östersjön, men är i andra områden i riskzonen för att utveckla Si begränsning om minskningen av DSi koncentrationer fortsätter. Resultaten skildrar Östersjöns resa från att vara ett havsområde med DSi halter som är tillräckliga för att understödja kiselalgernas produktion till ett sådant som kan uppleva Si begränsning och dess negativa ekologiska konsekvenser

Image of politicians in terms of the voters’ perception (the case of the Russian presidential election, 2012)

The article is devoted to the influence of communicative factors on citizens’ electoral behavior. It analyses the public speeches of candidates for presidency, finds the features of verbal and nonverbal communication of politicians and investigates the nuances of politicians’ presentation in the media. The article proposes a model for the analysis of candidates’ public communication in that the structure of image’s formation is used as a basis. The research presents practical recommendations for the domestic candidates to increase a number of the loyal voters by means of public speeches

НЕЙРОМАРКЕТИНГ ЯК ФАКТОР ІНВЕСТИЦІЙНОЇ ПРИВАБЛИВОСТІ ФІНАНСОВИХ ПОСЛУГ

The article describes a modern combination of marketing methods for studying the behavior of customers - neuromarketing. In order to determine the essence of neuromarketing, an analysis of the scientific works of scientists was conducted, which proved that neuromarketing is a part of marketing, which covers the study of unconscious processes of a person and the effect on the human brain. A new concept of “ neuromarketing banking ” has been derived, which includes a symbiosis of the main elements of neuromarketing and financial services. The types of neuromarketing are defined: the psychology of color, atmosphere, aromamarketing, sound design. In order to study the methods of introducing and using the neuromarketing in financial and banking institutions, the analysis of banks by profitability was provided. According to the survey, Raiffeisen Bank Aval ranked as the first one in terms of profitability in 2017. The analysis of the psychology usage of color in promotion of financial services. The techniques of aromamarketing that are the most effective in the activities of banking institutions are highlighted. It is proved that the emphasis make on the psychology of color in modern conditions of the financial - banking business development. As a result of the analysis, the direct connection of colors and their application in the design of financial and banking institutions, the creation of an atmosphere, which is expressed in the selection of light, music, planning, as well as the emphasis on aroma marketing were reflected. Aromatization of the airspace with certain flavours is directly proportional to customers attraction and creation of a favorable atmosphere. Audio marketing is successful in using it outdoors or using properly selected loudness when it comes to waiting rooms that are accompanied by queues. Thus, supporting competitiveness in the market, increasing the number of clients of financial and banking institutions, is directly proportional to the strategy they have developed to implement and use neuromarketing.В статті розглянуто сучасний комплекс маркетингових методів вивчення поведінки покупців – нейромаркетинг. Для визначення сутності нейромаркетингу було проведено аналіз наукових праць вчених, який довів, що нейромаркетинг це частина маркетингу, яка охоплює дослідження несвідомих процесів людини і вплив на людський мозок. Виведено нове поняття «банківський нейромаркетинг», який включає в себе симбіоз основних елементів нейромаркетингу і фінансових послуг. Визначено види нейромаркетингу: психологія кольору, атмосфера, аромамаркетинг, звуковий дизайн. Для дослідження методики впровадження і використання нейромаркетингу в фінансово - банківських установах, здійснено аналіз банків за прибутковістю. За даними дослідження  на першому місці за прибутковістю у 2017 р. знаходився Райффайзен Банк Аваль. Проведено аналіз застосування психології кольору для просування фінансових послуг. Виділено прийоми аромамаркетингу, які найбільш ефективні в діяльності банківських установ. Доведено,що в сучасних умовах розвитку фінансового - банківського бізнесу акцент робиться на психологію кольору. В результаті аналізу було відображено прямий зв'язок кольорів і їх застосування в дизайні фінансового - банківських установ, створення атмосфери, яка виражається в підборі світла, музики, планування, а також акцент на аромамаркетинг. Ароматизація повітряного простору певними ароматами прямо пропорційна залученню клієнтів і створення сприятливої атмосфери. Прийоми аудіо – маркетингу успішні за межами приміщення або ж із застосуванням правильно підібраної гучності, якщо це стосується залів очікування, які супроводжуються чергами. Таким чином, підтримка конкурентоспроможності на ринку, підвищення кількості клієнтів фінансово - банківських установ, прямо пропорційно залежить від розробленої ними стратегії впровадження і використання нейромаркетингу