1,721,435 research outputs found
Tapahtumaturvallisuuden käsikirja turvallisuusvastaavalle
Get PDFTämän opinnäytetyön tavoitteena oli kehittää turvallisuusalan yrityksen, Tran Xuan Secure Oy:n, valmiuksia toteuttaa tapahtumaturvallisuutta ammattimaisesti ja järjestelmällisesti. Tämän opinnäytetyön avulla yritys voi suunnitella ja toteuttaa tulevissa toimeksiannoissa turvallisuusjärjestelyjä erilaisissa pienissä ja keskikokoisissa yleisö- ja yksityistilaisuuksissa. Opinnäytetyössä tarkastellaan tapahtumaturvallisuuden keskeisiä osa-alueita, kuten tapahtumapaikan kartoitusta, riskienhallintaa, henkilöstön rooleja ja toimintaohjeita, viranomaisyhteistyötä sekä turvallisuusalan lainsäädäntöä. Lisäksi työssä käsitellään lyhyesti yrityksen asiakashankintaa, markkinointia ja maineenhallintaa, joiden avulla turvallisuusyritys voi rakentaa uskottavuutta, luotettavuutta ja hankkia uusia toimeksiantoja.
Työssä esitellään myös konkreettinen esimerkki opiskelijan aikaisemmasta toteutuneesta toimeksiannosta, jossa hän on itse toiminut turvallisuusvastaavana. Tapahtumaan sisältyi yli 600 hengen turvallisuussuunnittelu ja tämän toteutus. Esimerkin avulla avataan riskien arviointia, henkilöstöresurssien mitoitusta, ensiapuvalmiutta sekä tapahtuman aikaisen toiminnan operatiivista johtamista. Analyysi tulee tarjoamaan käytännön näkökulman siihen, kuinka suunnitelmat siirtyvät paperilta käytännön toteutukseen ja, että minkälaisia kehittämistoimenpiteitä voidaan tunnistaa tulevia toimeksiantoja varten.
Opinnäytetyön kokonaisuutta hyödyntämällä toimeksiantajayritys kykenee kehittämään pitkäjänteisesti omaa toimintaansa, osoittamaan ammattimaisuutensa asiakkaille sekä vahvistamaan asemaansa tapahtumaturvallisuuden palveluntarjoajana. Työ tulee toimimaan jatkossa myös perehdytys- ja koulutusmateriaalina yrityksen omille työntekijöille.
Opinnäytetyön tuotoksena syntyy tapahtumaturvallisuudesta käsikirja, jota voi hyödyntää muistin virkistyksenä kaikissa tulevissa toimeksiannoissa. Opinnäytetyöprosessi toteutettiin huhtikuun ja joulukuun 2025 välisenä aikana. Työssä hyödynnettyä ja analysoitua aikaisempaa toimeksiantoa oli toteutettu ja järjestetty 24.05.2025
Optimal Redistributive Policy in Debt Constrained Economies
No full textReplication files for "Optimal Redistributive Policy in Debt Constrained Economies," Journal of International Economics
Synchronization of perturbed Genesio-Tesi chaotic systems via a new finite-time control
No full textThis paper investigates the synchronization problem for perturbed Genesio-Tesi chaotic system. Based on Lyapnov stability theory, a new finite-time control method is proposed to ensure that the synchronization takes place in finite time. Numerical simulation results are provided to show the effectiveness of the proposed metho
Manipulating Magnetism through Voltage-Induced Oxygen Ion Migrations
No full textvoltage control of magnetism; magnetic anisotropy; skyrmion; RKKY interactions; interface.In the field of spintronics and nanomagnetic devices, Voltage Control of Magnetism (VCM) emerges as a promising technique for the energy-efficient regulation of material magnetism. This research delves into VCM within thin magnetic films, concentrating on the voltage effect that controls oxygen ion motion and consequently modifies the oxidation level at interfaces in multilayer magnetic film structures. The study begins by exploring the reversible transition between perpendicular magnetic anisotropy (PMA) and in-plane magnetic anisotropy (IMA) in Co layers within Pt/Co/Gd/GdOx/Pt multilayer structures, facilitated by bidirectional oxygen ion migrations. Moreover, this study unveils a mechanism to manipulate magnetic domains, thereby enabling the formation of skyrmions without the prerequisite of an in-plane external bias field and thermal assistance, exploiting the robust control over magnetic anisotropy at room temperature. To tackle the inherent challenge of VCM - the incapacity of the electric field to provide adequate torques for magnetization reversal in ferromagnetic materials - the research also explores electric field control of oxygen ions within a synthesized antiferromagnetic (sAFM) structure. Manipulating oxygen ions at interfaces allows for the manipulation of RKKY interactions, enabling reversible transitions between antiferromagnetic (AFM) and ferromagnetic (FM) orders of FM layers at room temperature. This mechanism permits the reversal of the magnetic moment direction of one of the two ferromagnetic layers in the sAFM structure without requiring an external magnetic field. Overall, this study provides a modest contribution to the extant understanding of voltage-controlled magnetism in multilayer thin films and gently advances the potential of energy-efficient spintronic devices.|본 논문은 스핀트로닉스 및 나노자기 장치 분야에서 자기의 전압 제어 (VCM)가 자료의 자기를 에너지 효율적으로 조절하는 유망한 기술로 부상함을 조사하였다. 연구는 얇은 자기 필름 내의 VCM에 대해 깊이 탐구하며, 다중 층 자기 필름 구조 내 계면에서의 산화 수준을 조정하는 산소 이온 운동을 제어하는 전압 효과에 중점을 둔다.
연구는 양방향 산소 이온 이동을 통해 Pt/Co/Gd/GdOx/Pt 다중층 구조 내의 Co 층에서 수직 자기 이방성 (PMA)과 평면 자기 이방성 (IMA) 사이의 가역적 전환을 탐구하는 것으로 시작된다. 또한, 상온에서 자기 이방성에 대한 견고한 제어를 활용하여 외부 바이어스 필드와 열 지원의 전제 조건 없이 스커미온을 형성할 수 있게 하는 자기 도메인 조작 메커니즘을 발견하였다.
VCM의 본질적인 도전인 강자성 재료에서의 자화 반전에 필요한 충분한 토크를 전기장이 제공할 수 없는 문제를 해결하기 위해, 연구는 합성 반강자성 (sAFM) 구조 내에서 산소 이온의 전기장 제어를 탐구하였다. 계면에서 산소 이온을 조작하여 RKKY 상호작용을 조절함으로써, FM 층의 반강자성 (AFM)과 강자성 (FM) 정렬 사이의 가역적인 전환을 상온에서 가능하게 하였다. 이 메커니즘을 통해 외부 자기장 없이 sAFM 구조의 두 강자성 층 중 하나의 자기 모멘트 방향을 반전시킬 수 있다.
총괄하여, 이 연구는 다중층 박막에서의 전압 제어 자기에 대한 현존하는 이해에 소박한 기여를 제공하며 에너지 효율적인 스피트로닉 장치의 가능성을 향상시키는데 기여할 것이다.ABSTRACT i
List of Content ii
List of Figures v
List of Tables xi
I. INTRODUCTION 1
II. BACKGROUND 4
2.1 Magnetic Anisotropy 4
2.2 Perpendicular Magnetic Anisotropy 5
2.3 Magnetic Hysteresis Loops 7
2.4 Domain walls 10
2.5 Dzyaloshinskii–Moriya Interaction (DMI) 13
2.6 Magnetic skyrmions 16
2.7 Ruderman-Kittel-Kasuya-Yosida (RKKY) 18
2.8 Voltage control magnetism (VCM) 20
III. EXPERIMENTAL METHODS 25
3.1 Sample Fabrication 25
3.2 Sample Characterization 31
IV. Voltage-Controlled Adjustment of Magnetic Anisotropy and Optimized Skyrmion
Generations 43
4.1 Overview 43
4.2 Experimental detail 44
4.3 Structure characterization 45
4.4 Magnetic Properties of As-Deposited sample 46
4.5 Control of Magnetic Anisotropy via Voltage-Driven O2- Migrations in the GdOx Layer
47
4.6 The transformation of the chemical composition of the Co top interface under the
effect of voltage 50
4.7 Asymmetric Time-Dependent MA Change under Negative and Positive Voltage Bias 51
4.8 Manipulation of Magnetic Domains by Voltage 56
4.9 Voltage-Assisted Formation of Magnetic Skyrmions 58
4.10 Determination of the type of the generated magnetic bubbles 62
4.11 Microscopic mechanism of skyrmion generation 63
4.12 Conclusion 64
V. Field-Free Control and Switching of Perpendicular Magnetization by Voltage Induced
Manipulation of RKKY Interaction 65
5.1 Overview 65
5.2 Analysis of RKKY Interactions and Exchange Bias in Ru-Spaced Heterostructures 67
5.3 Magnetic properties of the individual samples containing only the top-FM or bottom-
FM 70
5.4 Voltage Tuning of RKKY Interaction 72
5.5 Natural oxidation processes in multilayers 75
5.6 Voltage-Induced Perpendicular Magnetization Reversal in RKKY Multilayers 77
5.7 Conclusion 79
VI. Summary and outlook 80
6.1 Summary 80
6.2 Outlook 81
6.3 Concluding Remarks 84
References 85DoctordCollectio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
SRAM-based Physically Unclonable Function using Lightweight Hamming-Code Fuzzy Extractor for Energy Harvesting Beat Sensors
No full textBatteryless energy harvesting IoT sensor nodes such as beat sensors can be deployed in millions without the need to replace batteries. They are ultra-low-power and cost-effective wireless sensor nodes without the maintenance cost and can work for 24 hours/365 days. However, they were not equipped with security mechanisms to protect user data. Data encryption and authentication can be used to secure beat sensor applications, but generating a secure cryptographic key is challenging. In this paper, we proposed an SRAM-based Physically Unclonable Function (PUF) combining a high-reliability bit selection algorithm with a lightweight error-correcting code to generate reliable secure keys for data encryption. The system employs a feature of beat sensors, in which the microcontroller is powered on to transmit the ID signals and then powered off. This fits the SRAM-based PUF requirement, which needs the SRAM to be powered off to read out its random values. The proposed system has been evaluated on STM32 Cortex M0+ micro controllers and has been implemented to protect important data on beat sensors
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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