628 research outputs found
Dynamics of a dispersively coupled transmon qubit in the presence of a noise source embedded in the control line
No full textWe describe transmon qubit dynamics in the presence of noise introduced by an impedance-matched resistor (50 S2) that is embedded in the qubit control line. To obtain the time evolution, we rigorously derive the circuit Hamiltonian of the qubit, readout resonator and resistor by describing the latter as an infinite collection of bosonic modes through the Caldeira-Leggett model. Starting from this Jaynes-Cummings Hamiltonian with inductive coupling to the remote bath comprised of the resistor, we consistently obtain the Lindblad master equation for the qubit and resonator in the dispersive regime. We exploit the underlying symmetries of the master equation to transform the Liouvillian superoperator into a block diagonal matrix. The block diagonalization method reveals that the rate of exponential decoherence of the qubit is well-captured by the slowest decaying eigenmode of a single block of the Liouvillian superoperator, which can be easily computed. The model captures the often used dispersive strong limit approximation of the qubit decoherence rate being linearly proportional to the number of thermal photons in the readout resonator but predicts remarkably better decoherence rates when the dissipation rate of the resonator is increased beyond the dispersive strong regime. Our work provides a full quantitative description of the contribution to the qubit decoherence rate coming from the control line in chips that are currently employed in circuit QED laboratories and suggests different possible ways to reduce this source of the noise.Peer reviewe
How customer knowledge affects exploration: Generating, guiding, and gatekeeping
No full textFunding Information: The authors wish to thank Juha-Antti Lamberg, Jari Ojala, Kalle Pajunen, and Henrikki Tikkanen, as well as the reviewers and audience of the Academy of Management Annual Meeting (Vancouver, 2014), for their constructive feedback on earlier versions of the manuscript. The first author acknowledges the financial support of Foundation for Economic Education, Finland and the Jenny and Antti Wihuri Foundation . Publisher Copyright: © 2021 Elsevier Inc. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.The importance of understanding customers in order to sustain the long-term success of the company has been claimed by academics and practitioners for decades, to the point that the claim has turned into a truism. And still, the role of customer knowledge in organizational renewal, especially via explorative new product development (NPD), remains ambiguous. While existing literature generally emphasizes the value of customer knowledge, critics argue that a strong customer focus can also de-motivate and misguide exploration. This study adds clarity to our understanding of this tension by drawing from an intensive analysis of the corporate archives of a rapidly growing high-tech company. The authors trace the impacts of customer knowledge on twelve explorative NPD projects. The findings reveal three distinct mechanisms through which customer knowledge influences exploration: generating, guiding, and gatekeeping. The impact of customer knowledge on exploration depends on the selective deployment of these mechanisms. The authors further argue that managers should seek to find a fit between the deployment of customer knowledge mechanisms and the exploration project type in order to increase the likelihood of exploration project success.Peer reviewe
Tutkimus ympäristön vuorovaikutuksesta dispersiiviseen transmon kubittiin
No full textOne of the main ways of physically realizing quantum bits for the purposes of quantum technology is to manufacture them as superconducting circuits. These qubits are artificially built two-level systems that act as carriers of quantum information. They come in a variety of types but one of the most common in use is the transmon qubit. The transmon is a more stable, improved version of the earlier types of superconducting qubits with longer coherence times.
The qubit cannot function properly on its own, as it needs other circuit elements around it for control and readout of its state. Thus the qubit is only a small part of a larger superconducting circuit interacting with the qubit. Understanding this interaction, where it comes from and how it can be modified to our liking, allows researchers to design better quantum circuits and to improve the existing ones. Understanding how the noise, travelling through the qubit drive lines to the chip, affects the time evolution of the qubit is especially important. Reducing the amount of noise leads to longer coherence times but it is also possible to engineer the noise to our advantage to uncover novel ways of quantum control.
In this thesis the effects of a variable temperature noise source on the qubit drive line is studied. A theoretical model describing the time evolution of the quantum state is built. The model starts from the basic elements of the quantum circuit and leads to a master equation describing the qubit dynamics. This allows us to understand how the different choices made in the manufacturing process of the quantum circuit affect the time evolution.
As a proof of concept, the model is solved numerically using QuTiP in the specific case of a fixed-frequency, dispersive transmon qubit. The solution shows a decohering qubit with no dissipation. The model is also solved in a temperature range 0K < T ≤ 1K to show how the decoherence times behave with respect to the temperature of the noise source
Addressing substance use issues in adult social work
No full textThe objective of this thesis was to study the methods that are being used or would need further updating in adult social services when meeting clients with an already existing, or nascent substance abuse problem. As the new social and health care reform has just recently taken place in Finland and the primary focus has shifted to early identification and prevention work, these issues bring the subject of this thesis close to adult social service field.
The chosen method was a descriptive literature review. In theoretical framework the author explains the basic principles of adult social work (in Helsinki, Finland), substance abuse and the multidimensional harms it causes, mental health issues caused by substances, mini- intervention, and motivational interview. Data was collected through governmental and NGO websites, as well as written literature according to the title of thesis.
Thesis aims to find answers to a research question: How to use MI when meeting a client with substance abuse issues in adult social work?
The research showed that there are no simple answers as substance abuse is a broad and challenging subject that oftentimes requires multi-professional teamwork. Motivational interview itself, is a great tool and technique to implement, but it requires additional training and reviewing from the professionals. Studying motivational interviewing techniques should be made possible in Social Service studies, especially for those students who wish to broaden their knowledge in effective and preventative mental health – and substance abuse work
Scalable Text Mining with Sparse Generative Models
No full textThe information age has brought a deluge of data. Much of this is in text form, insurmountable in scope for humans and incomprehensible in structure for computers. Text mining is an expanding field of research that seeks to utilize the information contained in vast document collections. General data mining methods based on machine learning face challenges with the scale of text data, posing a need for scalable text mining methods.
This thesis proposes a solution to scalable text mining: generative models combined with sparse computation. A unifying formalization for generative text models is defined, bringing together research traditions that have used formally equivalent models, but ignored parallel developments. This framework allows the use of methods developed in different processing tasks such as retrieval and classification, yielding effective solutions across different text mining tasks. Sparse computation using inverted indices is proposed for inference on probabilistic models. This reduces the computational complexity of the common text mining operations according to sparsity, yielding probabilistic models with the scalability of modern search engines.
The proposed combination provides sparse generative models: a solution for text mining that is general, effective, and scalable. Extensive experimentation on text classification and ranked retrieval datasets are conducted, showing that the proposed solution matches or outperforms the leading task-specific methods in effectiveness, with a order of magnitude decrease in classification times for Wikipedia article categorization with a million classes. The developed methods were further applied in two 2014 Kaggle data mining prize competitions with over a hundred competing teams, earning first and second places
Analytical solution of the open dispersive Jaynes-Cummings model and perturbative analytical solution of the open quantum Rabi model
No full textThe Jaynes-Cummings and quantum Rabi models are fundamental to cavity and circuit quantum electrodynamics, as they describe the simplest form of light-matter interaction, where a single qubit is coupled to a single bosonic mode. A scenario that is commonly encountered in the experimental practice arises when the bosonic mode interacts with an external dissipative thermal bath, making the qubit-boson system open. In this work, we present new analytical solutions of the Lindblad master equations for the open Jaynes-Cummings and quantum Rabi models in the limit of weak qubit-boson coupling g, using the holomorphic formalism in Bargmann space. Specifically, we derive the most general solution of the local Lindblad master equation for the open dispersive Jaynes-Cummings model coupled to a thermal bath, with the only assumptions that the initial state of the qubit-boson system is separable. Additionally, we obtain a perturbative analytical solution for the open quantum Rabi model up to second order in g. Notably, our findings include a new formula for the qubit’s steady state at zeroth order, showing that the stationary populations depend on both qubit and boson frequencies in the quantum Rabi model, but not in the Jaynes-Cummings model. Our results are of general interest to the study of open quantum systems in the context of light-matter interaction.Peer reviewe
Tacit Knowledge Transfer at the Palveluyritys Oy Helsinki sales department through the perspective of an sales manager
No full textTiivistelmä
Tekijä: Antti Korkki
Tutkielman nimi: Hiljaisen tiedon siirtäminen Palveluyritys Oy:n Helsingin myyntiosastolla myyntipäällikön näkökulmasta
Tiedekunta: Kauppatieteellinen tiedekunta
Maisteriohjelma: Tietojohtaminen
Vuosi: 2014
Pro gradu –tutkielma: Lappeenrannan teknillinen yliopisto
88 sivua, 20 kuvaa ja yksi taulukko
Tarkastajat: Professori Markku Ikävalko
Tutkijatohtori Anna-Maija Nisula
Hakusanat: Hiljainen tieto, tiedon jakaminen ja osaaminen
Kiristynyt kilpailutilanne kuljetusalalla pakottaa alan yritykset etsimään uusia keinoja strategisen kilpailuedun saavuttamiseksi. Palvelualan yritykselle merkittävin kilpailukeino on palvelun laadulla kilpaileminen ja korkean laadun saavuttamiseksi on tärkeää, että oikea tieto on oikeassa paikassa oikeaan aikaan. Tämä tarkoittaa käytännössä reaaliaikaisten tiedon siirtämisen menetelmien käyttämistä.
Tämän tutkimuksen tarkoituksena on selvittää Palveluyritys Oy:n Helsingin myyntiosaston tiedon siirtämisen foorumien nykytilanne myyntipäällikön näkökulmasta. Lisäksi tutkimuksella etsitään keinoja tehostaa hiljaisen tiedon siirtämistä Palveluyritys Oy:n Helsingin myyntiosastolla. Tutkimuksessa käytetään laadullista tutkimusmenetelmää ja teoriaohjaavaa sisällön analyysiä.Abstract
Author: Antti Korkki
Title: Tacit Knowledge Transfer at the Palveluyritys Oy Helsinki sales department through the perspective of an sales manager
Faculty: LUT, School of Business
Masters Program: Master´s Degree in Knowledge Management
Year: 2014
Master´s Thesis: Lappeenranta University of Technology
88 pages, 20 figures and 1 table
Examiners: Prof. Markku Ikävalko
Senior Researcher Anna-Maija Nisula
Keywords: Tacit knowledge, knowledge sharing and know-how
The increased competition in the transport business has forced companies to seek new ways of achieving strategic competitive advantage. In the service industry a significant competitive tool is to compete on the quality of service and in order to ensure high quality, it is important that the right information is in the right place at the right time. In practice this means the usage of real-time data transfer techniques.
The purpose of this study is to determine the current situation of the knowledge transfer platforms in Palveluyritys Oy at the Helsinki sales department through the perspective of an sales manager. In addition, this study seeks to explore ways to enhance the transfer of tacit knowledge at the Helsinki sales department of Palveluyritys Oy. The study uses a qualitative research method along with theoretical content analysis
Ensuring Ecosystem Service Provision of Urban Water Nature-Based Solutions in Infill Areas: Comparing Green Factor for Districts and SWMM Modeling in Scenario Assessment
No full textFunding Information: Work of Niklas Dahlberg and Antti Rehunen has been part of ATeNAS-project (To Ally Technology, NAture and Society for integrated urban water management) that has been funded by Water JPI WaterWorks 2017. Publisher Copyright: © 2023, The Author(s).This study aims to explore the measurement of potential synergies between water management objectives and other ecosystem services generated by Nature-Based Solutions (NBS) in the context of urban planning. The research also investigates the comparative benefits of two analytical methods, Storm Water Management Model (SWMM) and green area factor for districts (GAFD). The study employs Malmi district in Helsinki, Finland, as a case study, examining five distinct NBS scenarios with varying degrees of integration. The results affirm that NBS can indeed enhance ecosystem services provision and stormwater management. The comparative analysis of the two methods, reveals that scenarios with high green factors exhibit effective flood risk reduction, while those with low green factors struggle to manage water, emphasizing the importance of balancing green and built elements in urban planning for optimal flood risk reduction. Furthermore, the study underscores the advantages of the two methods: GAFD offers simplicity and lower expertise requirements, generating valuable insights into ecosystem services, while SWMM provides precise stormwater management data. The findings emphasize the significance of diverse NBS combinations that harness the multifunctional aspects of green infrastructure, highlighting the need for integrated urban planning. The utilization of GAFD analysis provides a comprehensive districtwide perspective in a flexible manner, thereby improving the comprehension of the interconnected nature of urban green spaces. Highlights: Nature-based solutions (NBS) support urban stormwater management in infill areas.Green Area Factor for Districts (GAFD) is a practical tool to compare NBS options.GAFD and SWMM modeling results on stormwaters are comparable for common rain events.NBS size, quality and diversity reduce peak flows and enhance ecosystem services.Assessment of scenarios with the GAFD tool helps to identify multiple benefits of NBS.Peer reviewe
Greed is good? Of equilibrium impacts in environmental regulation
No full textFunding Information: I thank the editor and three anonymous referees, as well as Lassi Ahlvik, Erik Ansink, Janne Artell, Antti Belinskij, Daniel Hauser, Antti Iho, Markku Kallio, Saija Koljonen, Matti Liski, Niko Soininen, Juuso Välimäki, and participants at seminar in Helsinki and at EAERE 2021 and EAERE 2022 conferences for valuable comments and suggestions. Funding from the Academy of Finland project Regoverning the Existing Hydropower System is gratefully acknowledged. The author certifies that he has no affiliations with or involvement in any organization or entity with any financial interest, or non-financial interest in the subject matter or materials discussed in this manuscript. Publisher Copyright: © 2023 The Author(s)This paper presents a novel method to quantify the market equilibrium impacts of tighter environmental policies. The approach is taken to evaluate the welfare effects of emerging environmental regulations to protect the biodiversity of river ecosystems that put pressure on reducing hydropower generation capacity. A dataset of 129 million bids in the Nordic electricity market is used to calculate how small reductions in hydropower capacity change market outcomes and surpluses hour-by-hour for the years 2011–2022. Reaching the EU Biodiversity Strategy target of 2030 is estimated to reduce 56 MW of hydropower capacity in Finland. Such a change would lead to quantifiable welfare losses of €62 million over time, not counting environmental benefits. Notably, the producer surplus increases by €318 million over time through electricity market price changes, suggesting that instead of lobbying against biodiversity enhancing regulation, agreeing to an industry-wide implementation could benefit both the environment and the firms. Yet the fact that consumer costs increase more than the mere implementation cost reads as a sign of caution when tighter biodiversity policies are introduced.Peer reviewe
ISO9001 Quality Management Systems; Benefits and Requirements
No full textOulu University of Applied Sciences
Industrial Management
Author(s): Antti Viro
Title of thesis: ISO9001 Quality Management Systems; Benefits and Requirements
Supervisor(s): Hannu Päätalo
Spring 2015: Pages: 61 + 1 appendices
The purpose of this thesis was to find reasons and justifications for the ISO9001 certified quality management system.
The major part of the case work was establishing QMS for Dedicated Networks Partners Oy. The other parts were literature and theory research about ISO9001 certifications. The third part was the case survey about quality expectations among customers of Dedicated Network Partners Oy.
The results of this thesis were an ISO9001 certification and an analysis of certifications process. Another outcome was comparing of the results of the case work to published research papers about ISO9001 and its certification.
The conclusions show that similar benefits of ISO9001 can be found from different countries and different industries. In addition ISO9001 is only a tool for high quality, it has to be used in a correct way to achieve benefits to the business
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