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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A tool for comparing costs of conveyor network layouts

Aliwarga, Ivan Sutopo January 2001 (has links)
No description available.
2

An Alternative Planting Treatment for Turf Open Spaces in Conservation Subdivisions

Krueger, Timothy William 27 April 2001 (has links)
As conservation subdivisions increase in popularity, large tracts of community open spaces are being created. The typical landscape treatment is usually reminiscent of the English Landscape School: acres of turf providing little wildlife habitat or environmental benefits. Many homeowners are sold on the idea of great expanses of turf similar to a golf course. The open spaces are generally left to the homeowners association to maintain. In some cases it is donated to local municipalities. Maintenance is often expensive and places a burden on local governments. This study will show that creating more sustainable open spaces can correct this problem. This can be accomplished through the use of an ecologically based planting design. The following thesis project focuses on an alternative landscape planting treatment for these large open spaces, a treatment that has a significant cost savings and offers a different experience. / Master of Landscape Architecture
3

Husväggar av massivträ: En kostnadsjämförelse / House walls of solid wood: A cost comparison

Sundberg, Martin, Åsberg, David January 2012 (has links)
Trä är och har sedan länge varit en av Sveriges mest exporterade råvaror. Branschen sysselsätter idag omkring 100 000 människor i landet. I samband med de senaste årens miljödiskussioner bör husens uppbyggnad diskuteras. Syftet med detta examensarbete är att främja husbyggnation i massivträ som de senaste åren fått mer publicitet inte bara på den svenska marknaden men också i centraleuropeiska länder. Frågorna i detta arbete handlar om att identifiera de vanligast förekommande ytterväggskonstruktionerna och jämföra deras materialkostnader samt kostnader för arbete vid montering. För att ha kunnat göra en rättvis jämförelse har BBR’s energikrav varit den gemensamma nämnaren för ytterväggskonstruktionerna. Frågorna har besvarats genom intervjuer med tillverkare av prefabricerade massivträväggar, träregelväggar och betongväggar varpå energiberäkningar utförts i samband med framtagning av olika väggkonstruktioner för att få fram tre lika energieffektiva väggar. Dessa väggar har sedan kostnadsjämförts. Resultatet visar att den vanligast förekommande massivträväggen består av tre till fem lager korslimmade bräder som tillsammans bildar en KL-skiva. På dessa kan isolering och fasad appliceras och på så sätt få en vägg jämförbar med en träregelvägg eller betongvägg. Det visade sig efter gjorda undersökningar att massivträväggen är marginellt dyrare än träregelväggen men väsentligt mycket billigare än betongväggen. / Wood is and has long been one of Sweden’s most exported commodities. The industry currently employs about 100 000 people in the country. In conjunction with the recent environment discussions the construction of houses should also be discussed. The purpose of this study is to promote housing construction in solid wood, which in recent years has received more publicity not only in the Swedish market but also in central European countries. The questions in this project is about identifying the most common exterior wall constructions and compare their costs for materials and labor costs during assembly. To have a fair comparison, the BBR's energy requirements have been the common denominator of the exterior wall constructions. The questions have been answered through interviews with manufacturers of prefabricated solid wooden walls, wooden stud walls and concrete walls after which energy calculations conducted in connection with the development of various wall constructions to produce three equal energy-efficient walls. These walls have then been compared by their costs. The results show that the most common wall of solid wood consists of three to five layers of cross-laminated planks that make up a CLT-board. On these insulation and façade are applied and thus obtain a wall which is similar to the wooden stud wall or concrete wall. It was found after the investigations were made that the wall of solid wood is marginally more expensive than the wooden stud wall but significantly cheaper than the concrete wall.
4

Alternativní paliva v dopravě / Alternative fuels for transport

Běláčková, Adéla January 2008 (has links)
The thesis Alternative fuels for transport is dealing with the topic of economic competitiveness and environmental advantages of alternative fuels in comparison to classical oil fuels in transport. First, the main transport related problems are discussed in detail, including the dependency on oil, emissions from transport and their impact on human health and the environment. Then, the different types of alternative fuels are presented, including the legal framework, possibility of tax exemption and subsidy financing. The comparison of emissions of alternative and classical fuels follows the logic of the whole life cycle of a fuel, using the Well-to-Wheel analysis as method. Emissions of greenhouse gases and emissions of pollutants of local importance are observed. The cost comparison is based on experience in public bus transport in the Czech Republic. Fixed, variable and total costs are compared for classical diesel, biodiesel, natural gas, LPG, hydrogen and an electric vehicle. The purpose of the study is to decide which of the alternative fuels represents a cost competitive option in comparison to classical diesel and also provides a reduction in total emissions. The results of the study are designed to help Krkonošské Metro Association to choose a suitable alternative fuel for a project in rail transport.
5

The use of supercapacitors in conjunction with batteries in industrial auxiliary DC power systems / Ruan Pekelharing

Pekelharing, Ruan January 2015 (has links)
Control and monitoring networks often operate on AC/DC power systems. DC batteries and chargers are commonly used on industrial plants as auxiliary DC power systems for these control and monitoring networks. The energy demand and load profiles for these control networks differ from application to application. Proper design, sizing, and maintenance of the components that forms part of the DC control power system are therefore required. Throughout the load profile of a control and monitoring system there are various peak currents. The peak currents are classified as inrush and momentary loads. These inrush and momentary loads play a large role when calculating the required battery size for an application. This study investigates the feasibility of using supercapacitors in conjunction with batteries, in order to reduce the size of the required battery capacity. A reduction in the size of the required battery capacity not only influences the cost of the battery itself, but also influences the hydrogen emissions, the physical space requirements, and the required rectifiers and chargers. When calculating the required size batteries for an auxiliary power system, a defined load profile is required. Control and monitoring systems are used to control dynamic processes, which entails a continuous starting and stopping of equipment as the process demands. This starting and stopping of devices will cause fluctuations in the load profile. Ideally, data should be obtained from a live plant for the purpose of defining load profiles. Unfortunately, due to the economic risks involved, installing data logging equipment on a live industrial plant for the purpose of research, is not allowed. There are also no historical data available from which load profiles could be generated. In order to evaluate the influence of supercapacitors, complex load profiles are required. In this study, an alternative method of defining the load profile for a dynamic process is investigated. Load profiles for various applications are approximated using a probabilistic approach. The approximation methodology make use of plant operating philosophies as input to the Markov Chain Monte Carlo simulation theory. The required battery sizes for the approximated profiles are calculated using the IEEE recommended practice for sizing batteries. The approximated load profile, as well the calculated battery size are used for simulating the auxiliary power system. A supercapacitor is introduced into the circuit and the simulations are repeated. The introduction of the supercapacitor relieves the battery of the inrush and momentary loads of the load profile. The battery sizing calculations are repeated so as to test the influence of the supercapacitor on the required battery capacity. In order to investigate the full influence of adding a supercapacitor to the design, the impact on various factors are considered. In this study, these factors include the battery size, charger size, H2 extraction system, as well as maintenance requirements and the life of the battery. No major cost savings where evident from the results obtained. Primary reasons for this low cost saving are the fixed ranges in which battery sizes are available, as well as conservative battery data obtained from battery suppliers. It is believed that applications other than control and monitoring systems will show larger savings. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
6

The use of supercapacitors in conjunction with batteries in industrial auxiliary DC power systems / Ruan Pekelharing

Pekelharing, Ruan January 2015 (has links)
Control and monitoring networks often operate on AC/DC power systems. DC batteries and chargers are commonly used on industrial plants as auxiliary DC power systems for these control and monitoring networks. The energy demand and load profiles for these control networks differ from application to application. Proper design, sizing, and maintenance of the components that forms part of the DC control power system are therefore required. Throughout the load profile of a control and monitoring system there are various peak currents. The peak currents are classified as inrush and momentary loads. These inrush and momentary loads play a large role when calculating the required battery size for an application. This study investigates the feasibility of using supercapacitors in conjunction with batteries, in order to reduce the size of the required battery capacity. A reduction in the size of the required battery capacity not only influences the cost of the battery itself, but also influences the hydrogen emissions, the physical space requirements, and the required rectifiers and chargers. When calculating the required size batteries for an auxiliary power system, a defined load profile is required. Control and monitoring systems are used to control dynamic processes, which entails a continuous starting and stopping of equipment as the process demands. This starting and stopping of devices will cause fluctuations in the load profile. Ideally, data should be obtained from a live plant for the purpose of defining load profiles. Unfortunately, due to the economic risks involved, installing data logging equipment on a live industrial plant for the purpose of research, is not allowed. There are also no historical data available from which load profiles could be generated. In order to evaluate the influence of supercapacitors, complex load profiles are required. In this study, an alternative method of defining the load profile for a dynamic process is investigated. Load profiles for various applications are approximated using a probabilistic approach. The approximation methodology make use of plant operating philosophies as input to the Markov Chain Monte Carlo simulation theory. The required battery sizes for the approximated profiles are calculated using the IEEE recommended practice for sizing batteries. The approximated load profile, as well the calculated battery size are used for simulating the auxiliary power system. A supercapacitor is introduced into the circuit and the simulations are repeated. The introduction of the supercapacitor relieves the battery of the inrush and momentary loads of the load profile. The battery sizing calculations are repeated so as to test the influence of the supercapacitor on the required battery capacity. In order to investigate the full influence of adding a supercapacitor to the design, the impact on various factors are considered. In this study, these factors include the battery size, charger size, H2 extraction system, as well as maintenance requirements and the life of the battery. No major cost savings where evident from the results obtained. Primary reasons for this low cost saving are the fixed ranges in which battery sizes are available, as well as conservative battery data obtained from battery suppliers. It is believed that applications other than control and monitoring systems will show larger savings. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
7

隨機利率下的保單成本比較 / Insurance Policy Cost Comparison Under The Stochastic Interest Rates

李享宗, Lee,Hsiang Tsung Unknown Date (has links)
本研究以隨機利率模型應用至淨現值法、邊際年利率法、比較利率法及內部報酬率法等保單成本評價方法中,藉此觀察多期保單年度的價值變化,進而找出保單的報酬率、成本值或指數所呈現的趨勢,並考量在相同的情況下,比較各險種的成本或報酬優劣,最後希望消費者能在合理的隨機利率下更清楚了解保單成本的概念,並基於消費者對於合理的保單成本分析需求,能提供主管機關對於揭露保單成本的規範有更多的參考。 / 本研究發現各種保單在隨機利率變化的情況下,分紅終身壽險於各種成本分析方法中皆有良好的表現,不論是在考量淨成本結構的淨現值法,或是考量儲蓄性質、投資報酬為主的比較利率法以及各年度的邊際報酬利率等方法,整體而言分紅終身壽險對於消費者及保險公司應該是最優質的選擇。 / 再者以內部報酬率法應用隨機利率模型分析年金保險,可得知傳統遞延年金的報酬優於利率變動型年金。另外由於各種成本評價方法所著重的要素不同,想要了解保單完整全面性的評價,透過數個不同性質的保單成本分析方法計算較能呈現客觀且適切評價結果。 / This research is applied in the Stochastic Interest Model to the appraised method of insurance policy cost, such as Net Present Value Method, Marginal Yield Method, Comparative Interest Rate Method and Internal Rate of Return…etc., so as to observe the annual variation of value for different term of insurance policies, and then find out the rate of returns, cost value or trend appeared of index of the insurance policy, and consider it in the same cases to compare the good and bad from the cost or remuneration of every insurance. Hope consumers can finally clearer understand the concept of the insurance policy cost under the rational Stochastic Interest Rate, and on the basis of consumers’ demand for the rational insurance policy cost analysis can offer the competent authority more reference in revealing norms of the insurance policy cost. / In this research discovered that various insurance policies in changing of Stochastic Interest Rate, its Participating Whole-Life Insurance in varied cost analytical methods has good representation, no matter in considering the Net Present Value Method of the net cost structure, or considering Comparative Interest Rate Method of the main nature of deposits or main invest remuneration, and the annual marginal return interest rate…etc., the Participating Whole-Life Insurance should be generally the most high-quality choice to consumer and insurance company. / Moreover, according to the Internal Rate of Return, using the Stochastic Interest Model to analyze the annuity insurance can learn the remuneration of the Traditional Deferred Annuity is superior to the Interest Sensitive Annuity. In addition, as various cost appraised methods focused on different elements, if want to comprehension overall appraisal of insurance policy, then it can represent more objective and appropriate calculation through the analytical method of several different nature insurance policy cost.
8

Operating Cost Analysis of Electric Aircraft on Regional Routes

Shahwan, Kawthar January 2021 (has links)
The future of electric aircraft is closing in, with several companies racing to develop the first electric aircraft for commercial use. Researchers believe that electric aircraft have many benefits compared to conventional aircraft: the decrease of emissions, cheaper costs in the chain of development from manufacturing to ticket prices and a decrease in both fuel costs and overall operating costs. Amidst the race for the development of electric aircraft for commercial purposes between new and existing manufacturers, there is missing information which is needed to understand the profitability of electric aircraft. The question remains of how much the cost will change between conventional aircraft and electric aircraft. The aim of this study is to compare the operating cost of an electric aircraft (with 19 seats) to similar conventional aircraft on regional routes. The comparison would inform the decision of airlines interested in investing in electric aviation. To help achieve the aim of the study, a comparison analysis, a cost calculation, and analysis, as well as a SWOT analysis were performed using data gathered through literature search, a case study, and interviews. The study was performed on two conventional aircraft, the Beechcraft 1900D and the Jetstream JS31, both turboprop aircraft powered by jet fuel, and an electric aircraft, Heart Aerospace’s ES-19. Common for all aircraft is the capacity of 19 seats and their utilization for short-range flights. The total cost of electric aircraft is between 15 to 22% cheaper than the operating cost for conventional aircraft. The most expensive category for electric aircraft is the ownership cost, which can be reduced through mass production of electric aircraft, as the ownership cost of aircraft is generally higher when fewer aircraft are made. The electric aircraft is currently at a disadvantage due to the weight of the batteries and overall aircraft weight, which increases the weight-related airport charges. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
9

Hyra eller köpa rörläggarutrustning? / Renting or buying pipelaying - equipment?

Forsgårdh, Felix, Dahlin, Karl January 2019 (has links)
This report will try to give clarity in when and if it is most advantageous for a specific pipelaying entrepreneur to invest in buying pipelaying-equipment or renting it to their pipelaying-projects. The purpose of the report is also to give the reader a good perception of both alternatives as it could be a useful tool in future procurements. The information and prices that is used for the calculations in this report are gathered through the entrepreneur’s calculation-section, interviews with field-experts, rental companies, books and publications and internet. The report is limited to equipment that pipelayers normally are in need of in projects and the specific usage percentage is not used in the calculations. The result in this report shows what equipment is needed in a typical pipelaying-project and when it is best economically for a company to buy or rent their equipment both as individual articles and as a complete set. The result also shows that the hourly rate of buying the equipment is far less than the rate of renting it. It also brings up critical factors for investment-calculating regarding pipelaying-equipment. / Denna rapport ska skapa en ökad kunskap om och i sådana fall när det för ett specifikt företag inom mark- och anläggningsbranschen i Stockholmsområdet är fördelaktigt att själva investera eller hyra sin rörläggarutrustning i interna VA- projekt. Syftet med arbetet är även att kunna ge en god uppfattning av bägge kostnadsalternativen då det kan vara till nytta att använda sig av i framtida upphandlingar. Den information och de priser som legat till grund för beräkningarna i rapporten är inhämtade genom företagets ekonomiavdelning, intervjuer med sakkunnig personal, mailkontakt med hyresföretag samt informationssökning i litteratur, publikationsdatabaser samt internetsidor. Arbetet avgränsas till utrustning som rörläggare är i behov av för att klara av sitt dagliga arbete samt att den exakta nyttjandegraden av utrustningen inte vägs in i beräkningarna som återfinns i arbetet. Resultatet i den här rapporten visar vad som bör ingå i en typisk utrustning som en rörläggare behöver för att kunna utföra sitt arbete och när man tjänar på att hyra alternativt köpa sin rörläggarutrustning både som separata artiklar och som en komplett rörläggarcontainer. Arbetet visar också att själva timpriset för att köpa utrustningen är avsevärt lägre än timpriset för att hyra utrustningen. Slutligen tar rapporten upp avgörande faktorer för investeringskalkylering av rörläggarutrustning.
10

Automatic vs. Manual Data Labeling : A System Dynamics Modeling Approach / Automatisk Kontra Manuell Dataannotering : med Systemdynamiksmodellering

Blank, Clas January 2020 (has links)
Labeled data, which is a collection of data samples that have been tagged with one or more labels, play an important role many software organizations in today's market. It can help in solving automation problems, training and validating machine learning models, or analysing data. Many organizations therefore set up their own labeled data gathering system which supplies them with the data they require. Labeling data can either be done by humans or be done via some automated process. However, labeling datasets comes with costs to these organizations. This study will examine what this labeled data gathering system could look like and determine which components that play a crucial role when determining how costly an automatic approach is compared to a manual approach using the company Klarna's label acquisition system as a case study. Two models are presented where one describes a system that solely uses humans for data annotation, while the other model describes a system where labeling is done via an automatic process. These models are used to compare costs to an organization taking those approaches. Important findings include the identification of important components that affects which approach would be more economically efficient to an organization under certain circumstances. Some of these important components are the label decay rate, automatic and manual expected accuracy, and number of data points that require labeling. / Annoterad data, vilket är en kollektion utav datapunkter som har blivit annoterade med en eller flera taggar, spelar en viktig roll för många mjukvaruföretag i dagens marknad. Det kan hjälpa till att lösa automatiseringsingsproblem, träna och validera maskininlärningsmodeller, eller analysera data. Många organisationer sätter därför upp sina egna dataannoteringssystem som kan leverera den annoterade data som behövs inom organisationen. Annotering kan göras av människor, men kan också göras via en automatiserad process. Emellertid kommer annotering utav data med kostnader för organisationen. Denna studie undersöker hur ett sådant dataannoteringssystem kan se ut och analyserar vilka komponenter som spelar en betydande roll när kostnader mellan ett automatiserat system och ett manuellt system ska jämföras. Klarnas dataannoteringssystem kommer att användas som en case-studie. Två modeller presenteras varav den ena beskriver ett system där enbart manuellt annoteringsarbete utförs, och den andra beskriver ett system där annotering utav data utförs via en automatisk process. Några viktiga resultat av denna studie är identifikationen utav betydelsefulla parametrar i modellerna när det kommer till att jämföra den ekonomiska effektiviteten mellan de två olika dataannoteringsstrategierna. Exempel på dessa komponenter är annoteringens förfalltakt, den förväntade manuella/automatiska pricksäkerheten, och mängden data som behöver annoteras.

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