838 research outputs found

    The Doppler effect in an accelerated system and determining the acceleration of a sound source

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    Tijekom studija i u srednjoj školi Dopplerov efekt se obraduje i matematički opisuje za specifičan slučaj kad se izvor zvuka i opažač gibaju konstantnim relativnim brzinama. U ovom diplomskom radu će se pokušati opisati slučaj kad ta brzina nije konstantna, već se mijenja u vremenu. Konkretnije; razmotrit će se slučaj kad izvor zvuka jednoliko ubrzava, a opažač miruje. U skladu s tim pokušat će se teorijski predvidjeti kako se frekvencija koju registrira opažač mijenja za vrijeme ubrzavanja izvora zvuka, a zatim isto i eksperimentalno provjeriti te usporediti teorijsko predviđanje s dobivenim eksperimentalnim podacima. Pri eksperimentalnoj realizaciji je za uzrok jednoliko ubrzanog gibanja odabrana isključivo jedna sila, naime, gravitacijska sila. Budući da neke sile poput otpora zraka i sl. nisu mogle biti eksperimentalno eliminirane, akceleracija izvora zvuka nije mogla biti jednaka akceleraciji slobodnog pada, odnosno 9,81 m/s2, već je neizbježno morala biti nešto manja. Iz tog razloga se uz analizu zvuka provodila i analiza videozapisa akcelerirajućeg izvora zvuka, a iz koje je potom određena najvjerojatnija stvarna akceleracija izvora zvuka. Konačno, u ovom će se radu usporediti dobivene akceleracije izvora zvuka kao rezultati analiza videozapisa te zvučnog zapisa s pretpostavkom veće točnosti rezultata dobivenog analizom videozapisa te ocijeniti kakvoća analize Dopplerovog efekta za određivanje akceleracije jednoliko ubrzanog tijela.In secondary school and college physics courses the Doppler effect is studied and calculated in a specific case in which a sound source and observer are moving at a constant relative velocity. This thesis will try to describe the case in which the velocity is not constant but changes with time. More precisely, it will analyze the case of a uniformly accelerated sound source and a stationary observer. In accordance with that, the thesis will try to theoretically predict the changes in frequency measured by the observer during the acceleration of the sound source. This prediction will then be experimentally verified and the obtained data will be compared to the theoretical prediction. There is only one cause of uniformly accelerated motion of the sound source in our experimental setup: gravity. Considering the fact that air resistance and other disturbances could not be experimentally eliminated, inevitably the sound source acceleration had to be below the free fall acceleration of 9; 81 m/s2. For that reason, the video material with the falling sound source was examined alongside sound analysis to determine the most likely actual acceleration. Finally, this paper will compare the sound source accelerations obtained by both sound and video analyses, which accounts for greater accuracy of results, and evaluate the quality of the Doppler effect analysis for determining the acceleration of a uniformly accelerated body

    Face Deidentification with Generative Deep Neural Networks

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    Face deidentification is an active topic amongst privacy and security researchers. Early deidentification methods relying on image blurring or pixelization were replaced in recent years with techniques based on formal anonymity models that provide privacy guaranties and at the same time aim at retaining certain characteristics of the data even after deidentification. The latter aspect is particularly important, as it allows to exploit the deidentified data in applications for which identity information is irrelevant. In this work we present a novel face deidentification pipeline, which ensures anonymity by synthesizing artificial surrogate faces using generative neural networks (GNNs). The generated faces are used to deidentify subjects in images or video, while preserving non-identity-related aspects of the data and consequently enabling data utilization. Since generative networks are very adaptive and can utilize a diverse set of parameters (pertaining to the appearance of the generated output in terms of facial expressions, gender, race, etc.), they represent a natural choice for the problem of face deidentification. To demonstrate the feasibility of our approach, we perform experiments using automated recognition tools and human annotators. Our results show that the recognition performance on deidentified images is close to chance, suggesting that the deidentification process based on GNNs is highly effective.Comment: IET Signal Processing Special Issue on Deidentification 201

    Impact of coronary flow on parameters of a lumped model of the arterial tree

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    NEPRUŽANJE LIJEČNIČKE POMOĆI

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    Liječničke greške moguće klasificirati prema različitim kriterijima s tim da osnovna podjela kreće od onih koji su nastali činjenjem i onih koji su nastali nečinjenjem. Liječničke pogreške možemo još podijeliti i na grube ili teže i lakše; na greške po stadijima medicinske intervencije, dijagnostičke, terapijske, profilaktičke; na tehničke i taktičke; na opće, elementarne, u organizaciji rada, u informiranju itd. Jedno od oblika liječničke pogreške nastale nečinjenjem (propuštanjem) je i nepružanje medicinske pomoći. Kod ove vrste liječničke greške ključno je pitanje: kada nastaje obveza liječnika da ukaže liječničku pomoć? Radi se o nepružanju neodgodive medicinske pomoći osobi kojoj je takva pomoć potrebna zbog izravne opasnosti za njezin život. Liječnička radnja u danoj situaciji nameće se kao hitna, neizostavna, neizbježna, čije propuštanje može dovesti do ugrožavanja pacijentovog života. Autori ovog rada nastoje prikazati koji su elementi ovog oblika liječničke pogreške i način njihova ostvarivanja, budući je to od izuzetne važnosti zbog velikog broja dvojbi o postojanju ili nepostojanju liječničke pogreške u praksi.Medical malpractice can be classified according to different criteria, provided by that the basic divisions ranging from those that were created by acts and those incurred by omission. Medical errors can still divide and on rough or difficult and easier; on-error stages of medical intervention, diagnostic, therapeutic, prophylactic; the technical and tactical; in general, elementary, organized labor, the information and so on. One of the forms of medical errors caused by omission (failing) is lack of medical care. Key issue is: when the doctors obligation to take care of pacient starts. It is the failure to provide immediate medical care the person from whom such care is required because of direct threats to her life. Medical action in a given situation imposed as urgent, indispensable, unavoidable, whose failure can lead to compromising the patient\u27s life. The authors seek to show that the elements of this form of medical malpractice and way of their realization, as it is of the utmost importance because of the large number of doubts about the existence or non-existence of medical malpractice in practice

    PENGGUNAAN MEDIA GAMBAR SERI UNTUK MENINGKATKAN KETERAMPILAN MENULIS KALIMAT SEDERHANA SISWA KELAS II SEKOLAH DASAR

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    Penelitian ini dilatarbelakangi oleh rendahnya keterampilan siswa dalam menulis kalimat sederhana. Rendahnya keterampilan menulis siswa disebabkan karena dalam menulis kalimat sederhana dengan mengamati gambar, siswa masih binggung memilih kata untuk menuangkan ide yang ada dalam pikiran mereka.Gambar yang ada dalam buku siswa sulit dideskripsikan oleh siswa itu sendiri. Sehubungan dengan permasalahan di atas, maka cara tepat yang digunakan untuk perbaikan mutu pembelajaran Bahasa Indonesia di SDN S3 dalam meningkatkan keterampilan menulis kalimat sederhana dengan menggunakan media gambar seri karena dapat mempermudah siswa dalam menyusun sebuah karangan, paragraf ataupun kalimat sederhana sehingga pembelajaran akan lebih tertantang untuk membuat suatu karya tulis. Dan siswa dapat mudah menyusun kata-kata menjadi sebuah kalimat sederhana yang utuh. Metode yang digunakan dalam penelitian tindakan kelas dari Kemmis & Taggart (Arikunto, 2014, hlm. 74) yang terdiri dari empat tahapan yaitu: perencanaan, pelaksanaan, pengamatan dan refleksi dalam dua siklus penelitian dimana tiap siklus difokuskan pada materi tentang menulis kalimat sederhana dalam teks laporan sederhana dengan menggunakan media gambar seri. Penelitian ini dilaksanakan di SDN S3 kecamatan Sukasari, dengan subjek penelitian kelas II. Tujuan pelaksanaan tindakan kelas adalah untuk mengetahui bagaimana penggunaan media gambar seri dapat meningkatkan keterampilan menulis kalimat sederhana. Perencanaan pembelajaran dengan menggunakan media gambar seri dalam menulis kalimat sederhana pada siswa kelas II SD. Pelaksanaan penerapan dengan menggunakan media gambar seri dalam menulis kalimat sederhana pada siswa kelas II SD. Hasil belajar siswa dalam menulis kalimat sederhana setelah menggunakan media gambar seri pada siswa kelas II SD. Hal ini terlihat dari hasil belajar siswa mulai siklus I sampai siklus II yang mengalami kemajuan, dengan nilai persentasi siklus I 61,76% dan siklus II 97,05% dari KKM yaitu 72. Dengan demikian dapat disimpulkan bahwa penggunaan media gambar seri dapat meningkatkan keterampilan menulis siswa. Maka peneliti merekomendasikan kepada pendidik mengenai penggunaan media gambar seri sebagai media pembelajaran menulis kalimat sederhana, karena dengan menggunakan media gambar seri dapat menuangkan ide dan gagasannya ke dalam bentuk bahasa tulisan. ;--- This research is motivated by the lack of students' skills in writing simple sentences. Lack of writing skills of students due to write simple sentences by observing the images, students are still confused choose words for ideas that exist in their minds. Pictures in the book difficult students described by the students themselves. In connection with the above problems, the right way is used for the improvement of the quality of learning Indonesian in Public Alementary School S3 in improving the skills of writing simple sentences using the media image series because it can facilitate the students in preparing an article, a paragraph or a simple sentence so that learning will be more challenged to make a paper. And students can easily arrange the words into a simple sentence intact. The method used in the classroom action research of Kemmis& Taggart (Arikunto, 2014, p. 74), which consists of four phases: planning, implementation, observation and reflection in two cycles of study in which each cycle is focused on material about writing simple sentences in the text simple report using the media image series. This research was conducted in Public Alementary SchoolS3 Sukasari districts, with a grade II research subjects. The aim of implementing a class action is to know how to use the media image series can increase the skill of writing simple sentences. Planning learning by using media images in the series to write a simple sentence in grade IIAlementary School.Implementation of the application by using the media image series in write simple sentences in grade II AlementaryCchool. The results of students in writing simple sentences after using media image series in grade II AlementaryCchool. It is evident from the results of student learning begin the first cycle to the second cycle is progressing, with a percentage of the value of the first cycle and cycle II 61.76% 97.05% from KKM is 72. It can be concluded that the use of the media image series can improve skills writing students. The researchers recommend to educators regarding the use of media image series as a medium of learning to write simple sentences, because by using the media image series can pour his ideas in the form of written language

    Wavefunction Embedding for Molecular Polaritons

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    Polaritonic chemistry relies on the strong light-matter interaction phenomena for altering the chemical reaction rates inside optical cavities. To explain and to understand these processes, the development of reliable theoretical models is essential. While computationally efficient quantum electrodynamics self-consistent field (QED-SCF) methods, such as quantum electrodynamics density functional theory (QEDFT) needs accurate functionals, quantum electrodynamics coupled cluster (QED-CC) methods provide a systematic increase in accuracy but at much greater cost. To overcome this computational bottleneck, herein we introduce and develop the QED-CC-in-QED-SCF projection-based embedding method that inherits all the favorable properties from the two worlds, computational efficiency and accuracy. The performance of the embedding method is assessed by studying some prototypical but relevant reactions, such as methyl transfer reaction, proton transfer reaction, as well as protonation reaction in a complex environment. The results obtained with the new embedding method are in excellent agreement with more expensive QED-CC results. The analysis performed on these reactions indicate that the strong light-matter interaction is very local in nature and that only a small region should be treated at the QED-CC level for capturing important effects due to cavity. This work sets the stage for future developments of polaritonic quantum chemistry methods and it will serve as a guideline for development of other polaritonic embedding models
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