This research addresses fleet-sizing for reusable containers that are used for protection, transportation, and storage of parts between a component plant and assembly plant. These reusable containers are often expensive and occupy a large amount of storage space when empty and full. Having a large container fleet comes with higher acquisition, maintenance, and storage costs, but decreases production down time caused by the lack of containers needed for storage. A quantitative model of these trade-offs will permit decision makers to maintain desired production levels at minimum cost. In this dissertation, the relationship between container fleet size and production down time caused by container shortages is researched. Utilizing both theoretical and empirical approaches, two analytical models that include relevant operational parameters and stochastic components are developed. The first is a container fleet sizing model, and the second model estimates production stoppages as a function of container fleet size. The formulas are shown to be accurate and provide decision makers with the tools to better plan and manage specific applications. The formulas also provide general insight into the factors that affect container fleet size and production stoppage due to container shortages. / Graduation date: 2012

Este projeto objetiva discutir as experiências na estiva de duas gerações de trabalhadores do Porto de Santos, localizado no litoral sul do Estado de São Paulo, a partir das mudanças na cultura e na organização do trabalho decorrentes da introdução dos contêineres, na década de 1960, e da promulgação da Lei de Modernização dos Portos, em 1993. O trabalho pretende analisar este processo por meio de uma investigação empírica com pais e filhos estivadores, a fim de identificar as diferentes percepções das mudanças no setor portuário. O objetivo é o de descrever como cada geração vivenciou as transformações impostas pelo novo cenário de produção e de que forma realizou-se o processo de herança e de transmissão da cultura da estiva. Por meio de um estudo empírico com estivadores de duas gerações espera-se identificar as diferentes práticas vividas no âmbito do trabalho e na esfera social. A história oral é o principal aporte metodológico para captar a experiência e buscar a memória dos estivadores. Desta forma, a pesquisa debate sobre a herança da cultura da estiva entre pais e filhos e as permanências e as rupturas na transmissão geracional / This project discusses the work experiences of two generations of stevedoring workers at the Port of Santos, located on the southern coast of São Paulo. We consider the changes in the culture and the organization of work due to the introduction of containers, in the 1960s, and the creation of the Port Modernization Law in 1993. The study aims to examine this process through an empirical research with parents and sons, all stevedores, in order to identify the different perceptions of the changes occurred in the port sector with the 1993´s Law. The objective is to describe how each generation has experienced the changes imposed by the new production scenario and how the process of inheritance and transmission of the culture of stowage works. Considering this empirical study of two generations of stevedores we expect to identify different experiences in the work of stevedoring and in the social sphere. Oral history is the main methodological approach to capture the experiences and to register the memory of the stevedores. This research debates the heritage of culture stowage and the permanence and ruptures in the generational succession

Investigação crítica dos processos de intervenção urbana em áreas centrais históricas. Analisa o aprofundamento das formas de segregação causadas pela valorização desses espaços, a redefinição do papel da cultura e a contraposição entre discursos e políticas, revelando a contradição entre produção socializada do espaço e sua apropriação privada. Discute aspectos do processo de empresariamento da produção da cidade, que incorpora o Patrimônio Cultural de áreas históricas às dinâmicas de promoção das cidades no mercado mundial, no qual a diferenciação é fundamental à competitividade. Trata-se da mercantilização da cultura que resulta na banalização da paisagem urbana, reduz e simplifica aspectos culturais, convertidos em objetos de consumo. Propõe o estudo de intervenções realizadas no Centro Histórico de Salvador e no Bairro do Recife. Para tanto, estabelece marcos conceituais específicos, definidos a partir dos elementos definidores da Urbanalização e do Processo de Containerização do Espaço Urbano e de questões relativas à preservação do Patrimônio Cultural, considerando-se as relações entre Patrimônio Arquitetônico, Patrimônio Imaterial e as formas de vivência estabelecidas no território. Nesse sentido, o turismo, que privilegia as atividades de comércio e serviço em detrimento da habitação, é a chave de inserção dos marcos conceituais propostos e revela o processo de substituição e/ou afastamento dos grupos de usuários locais. Em nossas análises encontramos, no lugar do Turismo Cultural, apresentado como um modelo adequado para conciliar rentabilidade econômica, melhoria da qualidade do ambiente urbano e preservação do Patrimônio Cultural, um turismo predatório, direcionado para o mercado e voltado à média e alta renda, situação que privilegia grupos específicos direcionados ao consumo e compromete significativamente Identidades Culturais anteriormente estabelecidas. Em meio ao Processo de Privatização do Espaço Urbano, observa-se o comprometimento da cultura local face à ausência de seus agentes produtores e a desarticulação da dinâmica urbana cotidiana. A preocupação com essa temática se justifica porque o processo de conformação de novas dinâmicas urbanas compromete, ao menos em parte, a paisagem urbana anteriormente constituída. Sem as formas de apropriação e usos cotidianos anteriores, atrelados ao Patrimônio Imaterial e aos vínculos estabelecidos com o tempo, o que concede ao Patrimônio Arquitetônico e ao espaço urbano características específicas, vemos a transformação da paisagem em um cenário artificial, vigiado e controlado, para usos dirigidos, em horários determinados. Neste quadro de análise, a tese pretende contribuir com o debate sobre as formas contemporâneas de produção do espaço urbano, especialmente quanto ao papel das Áreas Centrais Históricas, levando à reflexão quanto às nuances entre a preservação de sua paisagem particular e os processos de banalização a que estão sujeitas. / Critical investigation of the urban intervention processes in historic central areas. It analyzes the deepening of the segregation forms caused by the appreciation of these spaces, the redefinition of the culture role and the contrast between discourses and policies, revealing the contradiction between socialized production of space and its private appropriation. It discusses aspects of the production of the city entrepreneurship process, which incorporates the Cultural Patrimony of historical areas to the promoting dynamic of the cities in the world market, in which differentiation is the key to competitiveness. This is the commodification of culture that results in the trivialization of the urban landscape, reduces and simplifies the cultural aspects converted into objects of consumption. It proposes the study of interventions realized in the historic center of Salvador and in the Recife District. To do so, it establishes specific conceptual frameworks, defined from the defining elements of the Urbanalization and Containerization Process of the Urban Space and of issues related to the preservation of the Cultural Patrimony, considering the relationship between Architectural Patrimony, Intangible Patrimony and ways of living established in the territory. In this sense, tourism, which focuses on the activities of trade and service over housing, is the key of the integration of proposed conceptual frameworks and reveals the process of replacement and/or removal of local user groups. In our analysis we have found, in the place of Cultural Tourism, presented as a suitable model for reconciling economic profitability, improvement of the urban environment quality and preservation of Cultural Patrimony, a predatory tourism, directed to the market and geared to middle and high-income, status which privileges specific groups targeted to consumption and significantly undermines Cultural Identities previously established. Amid the Privatization Process of Urban Space, there is the commitment of the local culture with the absence of its producing agents and the disarticulation of the quotidian urban dynamics. The concern with this topic is justified because the process of shaping new urban dynamics compromises, at least in part, the urban landscape previously constituted. Without the appropriation forms of and earlier quotidian use, linked to the Intangible Patrimony and to the links established along the time, which gives to the Architectural Patrimony and to the urban space specific characteristics, we see the transformation of the landscape in an artificial setting, monitored and controlled to directed uses, at certain times. In this framework of analysis, the thesis aims to contribute to the debate on contemporary forms of urban space production, especially regarding to the role of Historical Central Areas, leading to a reflection about the nuances between preserving their particular landscape and the trivialization processes to which they are subjected.

Software projects can nowadays have complex infrastructures behind them, in the form of libraries and various other dependencies which need to be installed on the machines they are being developed on. Setting up this infrastructure on a new machine manually can be a tedious process prone to errors. This can be avoided by automating the process using a software provisioning tool, which can automatically transfer infrastructure between machines based on instructions which can be version controlled in similar ways as the source code. Docker and Vagrant are two tools which can achieve this. Docker encapsulates projects into containers, while Vagrant handles automatic setup of virtual machines. This study compares Docker and Vagrant regarding their performance for machine level provisioning, both when setting up an infrastructure for the first time on a new machine, as well as when implementing a change in the infrastructure configuration. This was done by provisioning a project using both tools, and performing experiments measuring the time taken for each tool to perform the tasks. The results of the experiments were analyzed, and showed that Docker performed significantly better than Vagrant in both tests. However, due to limitations of the study, this cannot be assumed to be true for all use cases and scenarios, and performance is not the only factor to consider when choosing a provisioning tool. According to the data collected in this study, Docker is thereby the recommended tool to choose, but more research is needed to determine whether other test cases yield different results. / Moderna mjukvaruprojekt kan ha en komplex infrastruktur bakom sig, i form av bibliotek och andra beroenden som måste installeras på utvecklarmaskiner. Att konfigurera denna infrastruktur på en ny maskin manuellt kan vara en tidskrävande process, som även kan leda till en ofullständigt eller felaktigt konfigurerad lösning. Detta kan undvikas genom att automatisera processen med hjälp av provisioneringsverktyg, som automatiskt kan överföra infrastrukturer mellan maskiner baserat på instruktioner som kan versionshanteras på liknande sätt som källkoden. Docker och Vagrant är två verktyg som kan användas till detta ändamål. Docker kapslar in projektet i containers, medan Vagrant hanterar automatisk konfiguration av virtuella maskiner. Denna studie jämför Docker och Vagrant avseende deras prestanda för mjukvaruprovisionering på maskinnivå, både när det kommer till en förstagångsinstallation av infrastrukturen på en ny maskin, och även implementering av en ändring i konfigurationen av infrastrukturen. Denna jämförelse gjordes genom att implementera båda lösningarna, och sedan utföra experiment för att mäta tidsåtgången för båda verktygen att lösa de två uppgifterna. Resultaten av experimenten analyserades, och visade att Docker presterade bättre än Vagrant i båda tester. På grund av begränsningar i studien kan detta inte antas vara sant för alla användningsområden och scenarier, och prestanda är inte den enda faktorn att ha i åtanke när ett provisioneringsverktyg ska väljas. Baserat på datan insamlad i denna studie är Docker därmed verktyget som rekommenderas, men mer forskning krävs för att avgöra om andra testområden ger andra resultat.

<p>Maritime shipping is the most important mode of transportation for international trade. About 70 to 80 percent of the value traded worldwide moves by sea [1]. An inherent problem in global shipping markets is that non-competitive pricing behavior among carriers is widely believed to raise the cost of freight [2]–[5]. It is also likely that the effects of this problem on international trade flows and welfare are magnified by restricted cabotage reservation schemes. Historically, countries have implemented such policies to prohibit foreign competition in domestic shipping markets. The effects of protection on international goods trade are reasonably well understood. The effects of protection on service trade are less straight-forward. Issues of quality become more important, but they are challenging to measure. Moreover, most of these cabotage reservation schemes ban service imports. Therefore, this makes it complicated to compare domestic and foreign services in the same market, given that service activities are place-specific. </p> <p><br></p> <p>In order to better understand the effect of non-competitive pricing behavior in global shipping markets on international trade flows and the incidence of cabotage reservation schemes in shipping markets, I develop three essays. In the first Essay I focus on quantifying the economic effects of non-competitive pricing behavior in the maritime shipping industry on (1) freight costs, (2) international trade flows, and (3) economic welfare. The research question that I answer is: what share of observed shipping freight charges is attributable to non-competitive pricing behavior in maritime shipping markets? I estimate the maritime shipping mark-ups applying the method of Atkin and Donaldson [6] to U.S. Census import data of shipments moved by sea during the period 2002-2017. I find that freight mark-ups account for approximately one-third of total freight charges in U.S. imports. Carriers’ mark-ups thus represent an equivalent ad valorem tariff of 1.4-2.6 percent. U.S. imports of differentiated products would be 4.2 to 11.6 percent higher if these mark-ups were eliminated. The cost of these mark-ups in terms of economic welfare for U.S. consumers represents an annual reduction of 0.1-0.2 percent of their real income. Carriers also charge higher maritime shipping mark-ups (per kg.) to high-value products, products with a lower elasticity of substitution, and products with higher import tariffs. Imported products from developing countries or from distant countries to the U.S. are also charged with larger tariff equivalent mark-ups.  </p> <p><br></p> <p>In the second Essay I estimate the economic burden placed on Puerto Rico by the Jones Act. Using Lloyd’s List Intelligence (LLI) data to document the supply of shipping services in the U.S. -Puerto Rico shipping market, I find that the Jones Act fleet serving Puerto Rico contains no ships designed for the purpose of moving general cargo or bulk commodities. I then evaluate how this lack of supply of shipping services is a burden on imports of goods that would normally travel by ships of those kinds, modelling Puerto Rico’s import demand in a gravity framework. This exercise indicates that Puerto Rico’s demand for final goods exhibits a greater substitution towards non-U.S. sources among products that tend a) to be shipped by sea, b) to be physically heavy, and c) not to be moved in containers. I then estimate a structural gravity model to quantify the tariff-equivalent trade costs the Jones Act imposes on U.S. shipments. This model yields that the Jones Act represents a tariff equivalent of 30.6 percent on average across products. Finally, I use these estimates to calculate the compensating variation of Jones Act removal. I find that the cost of final expenditure in Puerto Rico would be $1.4 billion (about 1.3 percent) lower per year without the Jones Act. </p> <p><br></p> <p>Finally, in the third Essay I investigate what specifically explains the estimated change in Puerto Rico’s import demand for U.S. products due to the Jones Act. I use detailed data of vessels’ ports-of-call in the Caribbean from LLI to document issues of service quality and availability in maritime shipping services between the U.S. and Puerto Rico during the period 2004-2020, calculating metrics for some quality dimensions (e.g., vessels age, shipping capacity, shipping frequency and more). I also evaluate market conditions such as the concentration level in the market of carriers and shipyard building companies in order to examine the presumed incidence in shipping freight costs. Additionally, I use Puerto Rico’s import data from the Instituto de Estadísticas de Puerto Rico (IEPR) to evaluate how much the Jones Act restrictions affect the mode choice decisions for shipping products between U.S. mainland and Puerto Rico. The research question that I try to answer is: what is the level and evolution of the quality of shipping services provided by Jones Act-compliant vessels in the U.S.-Puerto Rico shipping market? </p>

<p>Dockerizing web servers has gained significant popularity due to its lightweight containerization approach, enabling rapid and efficient deployment of web services. However, the security of web server containers remains a critical concern. This study proposes a novel approach to enhance the security of Docker-based web servers using bpftrace to trace Nginx and Apache containers under attack, identifying abnormal syscalls, connections, shared library calls, and file accesses from normal ones. The gathered metrics are used to generate tailored AppArmor profiles for improved mandatory access control policies and enhanced container security. BPFtrace is a high-level tracing language allowing for real-time analysis of system events. This research introduces an innovative method for generating AppArmor profiles by utilizing BPFtrace to monitor system alerts, creating customized security policies tailored to the specific needs of Docker-based web servers. Once the profiles are generated, the web server container is redeployed with enhanced security measures in place. This approach increases security by providing granular control and adaptability to address potential threats. The evaluation of the proposed method is conducted using CVE’s found in the open source literature affecting nginx and apache web servers that correspond to the classification system that was created. The Apache and Nginx containers was attacked with Metasploit, and benchmark tests including ltrace evaluation in accordance with existing literature were conducted. The results demonstrate the effectiveness of the proposed approach in mitigating security risks and strengthening the overall security posture of Docker-based web servers. This is achieved by limiting memcpy and memset shared library calls identified using bpftrace and applying rlimits in 9 AppArmor to limit their rate to normal levels (as gauged during testing) and deny other harmful file accesses and syscalls. The study’s findings contribute to the growing body of knowledge on container security and offer valuable insights for practitioners aiming to develop more secure web server deployments using Docker. </p>

Среди имеющихся аналогов Discord-ботов в первой части работы доказывается и разбирается актуальность создания музыкального Discord-бота, и, вместе с тем, требования реализации его серверной части. Далее описывается выбранная методология разработки и поясняется выбор стека технологий, а именно фреймворк, база данных, необходимость и приложение для контейнеризации проекта. В третьей части приводится принцип работы основных частей функционала бота: взаимодействие с API, реализация плеера и способ воспроизведения музыки. В конце описывается способ тестирования серверной части бота и делаются выводы. Данная работа опубликована на конференции ИНТЕР в секции «Искусственный интеллект и программная инженерия» (2023 г.). / Among the available analogues of Discord bots, the first part of the work proves and examines the relevance of creating a music Discord bot, and, at the same time, the requirements for implementing its server part. The following describes the selected development methodology and explains the choice of technology stack, namely the framework, database, need and application for containerizing the project. The third part describes the operating principle of the main parts of the bot's functionality: interaction with the API, implementation of the player and the method of playing music. At the end, a method for testing the server side of the bot is described and conclusions are drawn. This work was published at the INTER conference in the section “Artificial Intelligence and Software Engineering” (2023).

This study aims to explore predictive scaling algorithms used to predict and manage workloadsin a containerized system. The goal is to identify which predictive scaling approach delivers themost effective results, contributing to research on cloud elasticity and resource management.This potentially leads to reduced infrastructure costs while maintaining efficient performance,enabling a more sustainable cloud-computing technology. The work involved the developmentand comparison of three different autoscaling algorithms with an interchangeable predictioncomponent. For the predictive part, three different time-series analysis methods were used:XGBoost, ARIMA, and Prophet. A simulation system with the necessary modules wasdeveloped, as well as a designated target service to experience the load. Each algorithm'sscaling accuracy was evaluated by comparing its suggested number of instances to the optimalnumber, with each instance representing a simulated CPU core. The results showed varyingefficiency: XGBoost and Prophet excelled with richer datasets, while ARIMA performed betterwith limited data. Although XGBoost and Prophet maintained 100% uptime, this could lead toresource wastage, whereas ARIMA's lower uptime percentage possibly suggested a moreresource-efficient, though less reliable, approach. Further analysis, particularly experimentalinvestigation is required to deepen the understanding of these predictors' influence on resourceallocation.

Thesis (MCom)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The South African fresh fruit export industry is concerned about fruit and financial losses due to temperature breaks within the fresh fruit export cold chain. The Port of Cape Town plays a crucial role in the export process as the majority of fruit reefer containers that are exported through Cape Town are handled by the Cape Town Container Terminal. This study focuses on the container terminal leg of the fresh fruit export process. Observations made in the Cape Town Container Terminal, at shipping lines and exporting companies show that certain procedures are not always followed in the Cape Town Container Terminal and that congestion and ineffective working methods are causing breaks within the fresh fruit export cold chain. Temperature and time data received from Transnet Port Terminals, shipping lines and exporting companies were analysed for the container terminal segment of the export process. From the data analysis it is clear that there are a large number of breaks originating within the container terminal and that the port is not operating efficiently. The study identifies areas of improvement and makes recommendations on improving some of the issues discussed.

Context. As the number of organizations using cloud application platforms to host their applications increases, the priority of distributing physical resources within those platforms is increasing simultaneously. The goal is to host a higher quantity of applications per physical server, while at the same time retain a satisfying rate of performance combined with certain scalability. The modern needs of customers occasionally also imply an assurance of certain privacy for their applications. Objectives. In this study two types of instances for hosting applications in cloud application platforms, virtual machines and application containers, are comparatively analyzed. This investigation has the goal to expose advantages and disadvantages between the instances in order to determine which is more appropriate for being used in cloud application platforms, in terms of performance, scalability and user isolation. Methods. The comparison is done on a server running Linux Ubuntu 16.04. The virtual machine is created using Devstack, a development environment of Openstack, while the application container is hosted by Docker. Each instance is running an apache web server for handling HTTP requests. The comparison is done by using different benchmark tools for different key usage scenarios and simultaneously observing the resource usage in respective instance. Results. The results are produced by investigating the user isolation and resource occupation of respective instance, by examining the file system, active process handling and resource allocation after creation. Benchmark tools are executed locally on respective instance, for a performance comparison of the usage of physical resources. The amount of CPU operations executed within a given time is measured in order determine the processor performance, while the speed of read and write operations to the main memory is measured in order to determine the RAM performance. A file is also transmitted between host server and application in order to compare the network performance between respective instance, by examining the transfer speed of the file. Lastly a set of benchmark tools are executed on the host server to measure the HTTP server request handling performance and scalability of each instance. The amount of requests handled per second is observed, but also the resource usage for the request handling at an increasing rate of served requests and clients. Conclusions. The virtual machine is a better choice for applications where privacy is a higher priority, due to the complete isolation and abstraction from the rest of the physical server. Virtual machines perform better in handling a higher quantity of requests per second, while application containers is faster in transferring files through network. The container requires a significantly lower amount of resources than the virtual machine in order to run and execute tasks, such as responding to HTTP requests. When it comes to scalability the prefered type of instance depends on the priority of key usage scenarios. Virtual machines have quicker response time for HTTP requests but application containers occupy less physical resources, which makes it logically possible to run a higher quantity of containers than virtual machines simultaneously on the same physical server.