2,904 research outputs found

    Selection of Projects for Project Portfolio Using Fuzzy TOPSIS and Machine Learning

    Get PDF
    Project portfolio management (PPM) is extremely important nowadays due to the increasing severe competitions, accelerated product developments, project complexity, uncertainty, and challenges from global competitors. Therefore, businesses involved in many (dozens or even hundreds) projects need to formulate tactics and strategies to secure firms’ competencies and, most importantly, increase their productivities. Under this globalization context, PPM is to opti-mize the value provided to the customers while minimizing risks and the resources committed to the projects, while critical success factors (CSFs) is applied to anticipate the project’s risk and financial value by early assessment thus to help from the organizational level to predict the per-formance. Despite its importance, the literature on PPM and CSFs at a project level is rather limited, which demands a more profound knowledge about the assessment, ranking, and prior-itization of projects in the early stage. This study seeks to address the following two research questions: Do CSFs vary according to the project category, and how a supportive method can be established to help portfolio managers to select the project for portfolio. As a result, this re-search focuses on the multi-project context in order to fill the above-mentioned research gaps. As the contributions of this study, this study intends to (1) verify the hypothesis that different project category has different CSFs, and (2) contribute to explore how machine learning technol-ogy can be utilized for project selection. Projektisalkun hallinta (PPM) on nykyään erittäin tärkeää lisääntyvien kovien kilpailujen, nopeutuneen tuotekehityksen, projektien monimutkaisuuden, epävarmuuden ja globaalien kilpailijoiden haasteiden vuoksi. Siksi moniin (kymmeniin tai jopa satoihin) hankkeisiin osallistuvien yritysten on laadittava taktiikat ja strategiat, joilla varmistetaan yritysten osaaminen ja mikä tärkeintä, lisää tuottavuuttaan. Tässä globalisaatiokehyksessä PPM: n on optimoitava asiakkaille tarjottu arvo minimoiden riskit ja hankkeisiin sitoutuvat resurssit, kun taas kriittisiä menestystekijöitä (CSF) käytetään ennakoimaan projektin riski ja taloudellinen arvo varhaisella arvioinnilla, jotta apua organisaatiotasolta suorituskyvyn ennustamiseksi. Tärkeydestään huolimatta kirjallisuus PPM: stä ja CSF: stä projektitasolla on melko rajallinen, mikä vaatii syvällisempää tietoa hankkeiden arvioinnista, luokittelusta ja ennakoinnista varhaisessa vaiheessa. Tässä tutkimuksessa pyritään käsittelemään kahta seuraavaa tutkimuskysymystä: vaihtelevatko CSF: t projektikategorian mukaan ja kuinka voidaan luoda tukeva menetelmä salkunhoitajien auttamiseksi valitsemaan projekti salkkuun. Tämän seurauksena tämä uudelleenhaku keskittyy moniprojektiyhteyteen edellä mainittujen tutkimuksen aukkojen täyttämiseksi. Tämän tutkimuksen myötä tämän tutkimuksen tarkoituksena on (1) tarkistaa hypoteesi, että eri projektikategorioilla on erilaiset CSF: t, ja (2) myötävaikuttaa siihen, kuinka koneoppimisen tekniikkaa voidaan hyödyntää projektin valinnassa

    Continuous change detection and classification of land cover using all available Landsat data

    Full text link
    Thesis (Ph.D.)--Boston UniversityLand cover mapping and monitoring has been widely recognized as important for understanding global change and in particular, human contributions. This research emphasizes the use ofthe time domain for mapping land cover and changes in land cover using satellite images. Unlike most prior methods that compare pairs or sets of images for identifying change, this research compares observations with model predictions. Moreover, instead of classifying satellite images directly, it uses coefficients from time series models as inputs for land cover mapping. The methods developed are capable of detecting many kinds of land cover change as they occur and providing land cover maps for any given time at high temporal frequency. One key processing step of the satellite images is the elimination of "noisy" observations due to clouds, cloud shadows, and snow. I developed a new algorithm called Fmask that processes each Landsat scene individually using an object-based method. For a globally distributed set ofreference data, the overall cloud detection accuracy is 96%. A second step further improves cloud detection by using temporal information. The first application ofthe new methods based on time series analysis found change in forests in an area in Georgia and South Carolina. After the difference between observed and predicted reflectance exceeds a threshold three consecutive times a site is identified as forest disturbance. Accuracy assessment reveals that both the producers and users accuracies are higher than 95% in the spatial domain and approximately 94% in the temporal domain. The second application ofthis new approach extends the algorithm to include identification of a wide variety of land cover changes as well as land cover mapping. In this approach, the entire archive of Landsat imagery is analyzed to produce a comprehensive land cover history ofthe Boston region. The results are accurate for detecting change, with producers accuracy of 98% and users accuracies of 86% in the spatial domain and temporal accuracy of 80%. Overall, this research demonstrates the great potential for use of time series analysis of satellite images to monitor land cover change

    Continuous change detection and classification of land cover using all available Landsat data

    Full text link
    Thesis (Ph.D.)--Boston UniversityLand cover mapping and monitoring has been widely recognized as important for understanding global change and in particular, human contributions. This research emphasizes the use ofthe time domain for mapping land cover and changes in land cover using satellite images. Unlike most prior methods that compare pairs or sets of images for identifying change, this research compares observations with model predictions. Moreover, instead of classifying satellite images directly, it uses coefficients from time series models as inputs for land cover mapping. The methods developed are capable of detecting many kinds of land cover change as they occur and providing land cover maps for any given time at high temporal frequency. One key processing step of the satellite images is the elimination of "noisy" observations due to clouds, cloud shadows, and snow. I developed a new algorithm called Fmask that processes each Landsat scene individually using an object-based method. For a globally distributed set ofreference data, the overall cloud detection accuracy is 96%. A second step further improves cloud detection by using temporal information. The first application ofthe new methods based on time series analysis found change in forests in an area in Georgia and South Carolina. After the difference between observed and predicted reflectance exceeds a threshold three consecutive times a site is identified as forest disturbance. Accuracy assessment reveals that both the producers and users accuracies are higher than 95% in the spatial domain and approximately 94% in the temporal domain. The second application ofthis new approach extends the algorithm to include identification of a wide variety of land cover changes as well as land cover mapping. In this approach, the entire archive of Landsat imagery is analyzed to produce a comprehensive land cover history ofthe Boston region. The results are accurate for detecting change, with producers accuracy of 98% and users accuracies of 86% in the spatial domain and temporal accuracy of 80%. Overall, this research demonstrates the great potential for use of time series analysis of satellite images to monitor land cover change

    catena-Poly[[[[3-(2-pyrid­yl)-1H-pyrazole]manganese(II)]-μ-oxalato] sesquihydrate]

    Get PDF
    In the title compound, {[Mn(C2O4)(C8H7N3)]·1.5H2O}n, the MnII ion is chelated by two O,O′-bidentate oxalate ions and an N,N′-bidentate 3-(2-pyrid­yl)pyrazole mol­ecule, resulting in a distorted cis-MnN2O4 octa­hedral geometry for the metal ion. The bridging oxalate ions generate wave-like polymeric chains propagating in [001]. The packing is consolidated by N—H⋯O and O—H⋯O hydrogen bonds. One of the water O atoms lies on a crystallographic twofold axis

    catena-Poly[[[[3-(2-pyrid­yl)-1H-pyrazole]cadmium(II)]-μ-oxalato] dihydrate]

    Get PDF
    In the title compound, {[Cd(C2O4)(C8H7N3)]·2H2O}n, the CdII ion is chelated by two O,O′-bidentate oxalate ions and an N,N′-bidentate 3-(2-pyrid­yl)-1H-pyrazole mol­ecule, thereby generating a distorted cis-CdN2O4 octa­hedral geometry. Adjacent pairs of Cd ions are bridged by oxalate ions, resulting in wave-like polymeric chains propagating in [100]. The packing is consolidated by N—H—O and O—H—O hydrogen bonds
    corecore