2,487 research outputs found
Gauged symmetry and baryogenesis via leptogenesis at TeV scale
It is shown that the requirement of preservation of baryon asymmetry does not
rule out a scale for leptogenesis as low as 10 TeV. The conclusions are
compatible with see-saw mechanism if for example the pivot mass scale for
neutrinos is that of the charged leptons. We explore the
parameter space - of relevant light and heavy neutrino masses
by solving Boltzmann equations. A viable scenario for obtaining baryogenesis in
this way is presented in the context of gauged symmetry.Comment: 15 pages, 4 figures, references added, match with journal versio
Robust Adaptive Control
Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known
B-L Cosmic strings and Baryogenesis
Cosmic strings arising from breaking of the gauge symmetry that
occurs in a wide variety of unified models can carry zero modes of heavy
Majorana neutrinos. Decaying and/or repeatedly self-interacting closed loops of
these ``'' cosmic strings can be a non-thermal source of heavy
right-handed Majorana neutrinos whose decay can contribute to the observed
baryon asymmetry of the Universe (BAU) via the leptogenesis route. The
cosmic strings are expected in GUT models such as SO(10), where they can be
formed at an intermediate stage of symmetry breaking well below the GUT scale
GeV; such light strings are not excluded by the CMB anisotropy
data and may well exist. We estimate the contribution of cosmic string
loops to the baryon-to-photon ratio of the Universe in the light of current
knowledge on neutrino masses and mixings implied by atmospheric and solar
neutrino measurements. We find that cosmic string loops can contribute
significantly to the BAU for symmetry breaking scale
\eta_{B-L}\gsim 1.7\times 10^{11}\gev. At the same time, in order for the
contribution of decaying cosmic string loops not to exceed the observed
baryon-to-photon ratio inferred from the recent WMAP results, the lightest
heavy right-handed Majorana neutrino mass must satisfy the constraint
M_1 \leq 2.4 \times 10^{12}(\eta_{B-L}/10^{13}\gev)^{1/2}\gev. This may have
interesting implications for the associated Yukawa couplings in the heavy
neutrino sector and consequently for the light neutrino masses generated
through see-saw mechanism.Comment: match with the published versio
Soliton-fermion systems and stabilised vortex loops
In several self-coupled quantum field theories when treated in semi-classical
limit one obtains solitonic solutions determined by topology of the boundary
conditions. Such solutions, e.g. magnetic monopole in unified theories
\cite{Hooft1974} \cite{Polyakov1974} or the skyrme model of hadrons have been
proposed as possible non-perturbative bound states which remain stable due to
topological quantum numbers. Furthermore when fermions are introduced, under
certain conditions one obtains zero-energy solutions
\cite{Vega1978}\cite{Jackiw1981} for the Dirac equations localised on the
soliton. An implication of such zero-modes is induced fermion number
\cite{Jackiw1977} carried by the soliton.Comment: 4 pages, presented at the 17th DAE-BRNS HEP symposium held at IIT
Kharagpur, Indi
Pola Perjalanan Penduduk Pinggiran Menuju Kota Surakarta Ditinjau Dari Aspek Aspasial dan Aspek Spasial
Kota Surakarta sebagai wilayah yang terus mengalami perkembangan telah menjadi daya tarik bagi penduduk di sekitar kawasan kota inti. Kawasan Kota Surakarta yang semula tidak padat akan berkembang pesat menjadi wilayah yang padat akan penduduk, akibat dari proses perjalanan yang dihasilkan para pelaku perjalanan khususnya dari pinggiran kota menuju kota inti. Hal ini akan menyebabkan semakin tingginya interaksi antara wilayah pinggiran kota dengan kota inti yang juga akan berdampak pada kemacetan lalu lintas dan kepadatan penduduk khususnya bagi Kota Surakarta sebagai kota inti. Penelitian ini dilakukan untuk mengetahui pola perjalanan penduduk pinggiran menuju Kota Surakarta sehingga akan dapat digambarkan bagaimana proses perjalanan yang dilakukan para penduduk pinggiran menuju Kota Surakarta, dan dari proses tersebutlah dapat diketahui penanganan yang tepat untuk menanggulangi permasalahan khususnya permasalahan transportasi di wilayah Kota Surakarta dan sekitarnya. Penelitian ini termasuk ke dalam penelitian deskriptif yang menggambarkan dan mendeskripsikan suatu kondisi yang spesifik dari suatu objek tertentu, dalam hal ini yaitu akan digambarkan secara deskriptif bagaimana pola perjalanan penduduk pinggiran yang terjadi dilihat dari aspek spasial dan aspek aspasial Dari hasil penelitian didapatkan bahwa berdasarkan tujuan perjalanan didominasi oleh tujuan bekerja yaitu sebesar 47% penduduk diikuti dengan tujuan pendidikan sebesar 27% dan tujuan berbelanja sebesar 26%. Selanjutnya berdasarkan tingkat pendapatan didominasi oleh penduduk dengan tingkat pendapatan kurang dari 1.145.000 rupiah, mayoritas penduduk telah memiliki kendaraan pribadi serta dominasi usia pelaku perjalanan yaitu antara 15-40 tahun yang dianggap sebagai usia produktif. Berdasarkan sebaran perjalanan diketahui bahwa dominasi guna lahan di Kota Surakarta yaitu perdagangan dan jasa, dan berdasarkan rute perjalanan didominasi penduduk melewati rute-rute jalan penghubung antara Kota Surakarta dengan pinggirannnya. Pada akhirnya dapat diketahui berdasarkan pola perjalanan menunjukan bahwa proses perjalanan yang dihasilkan penduduk pinggiran akan memberikan beban terhadap kawasan Kota Surakarta dan hal ini akan memicu terjadinya kepadatan lalu lintas serta perubahan fungsi ruang pada kawasan Kota Surakarta. Kata Kunci: interaksi wilayah, karakteristik perjalanan,, penelitian deskriptif, pola perjalanan
Low Error Rate Data Transmission in Cognitive Radio Networks
Cognitive Radio (CR) has become a hopeful technology to enhance the spectrum utilization through spectrum sharing between licensed user (primary user) and unlicensed user (secondary user). An vital rule mandated for the development of such frameworks are to develop solutions that don’t require any changes to the existing primary user (PU) infrastructure. An Orthogonal Frequency Division Multiplexing (OFDM) is typically worn advancements in present wireless communication systems which has the possibility of fulfilling the demand for cognitive radios intrinsically or with slight changes. In this paper, Space time block codes is used. The various antennas used on both ends for trustworthy data broadcast and interference nulling schemes. These codes can accomplish full broadcast diversification determined via the number of broadcast antennas. The MIMO is worn for enhancing the power of a wireless link, to determine the issue for lower BER and achieve a superior performance
Pemodelan Resiko Kecelakaan Berbasis Kondisi Kendaraan dan Pengemudi
Traffic accidents are particularly prone to occur mainly caused by vehicle speed, vehicle damage, alcohol influence, and fatigue. The study aims to model the risk of vehicle and driver-based accidents occurring across Queensland, Australia. The data in this study used a dataset of accident factors on Queensland state roads totaling 3412 accidents sourced from the Australian state government of Queensland. Research data period from 2001-2019. This research method uses multinomial logistic regression modeling analysis. The results of this study produced several models, namely; (1) Log odds in the risk level of death vs hospitalization will increase by 1,028 if affected by vehicle damage, increase by 0.731 if affected by fatigue, increase by 0.158 if affected by vehicle speed, increase by 0.151 if influenced by alcohol. (2) Log opportunities in the risk level of death vs. medical care will increase by 0.786 if affected by vehicle damage, increase by 0.375 if affected by fatigue, decrease by 0.003 if affected by vehicle speed, decrease by 0.078 if influenced by alcohol. (3) Log odds in the risk of death vs minor injury will increase by 0.484 if affected by vehicle damage, increase by 0.245 if affected by fatigue, decrease by 0.156 if affected by vehicle speed, decrease by 0.266 if influenced by alcohol. (4) Log odds in the risk of death vs property damage will increase by 1,254 if affected by vehicle damage, increase by 0.828 if affected by fatigue, increase by 0.185 if influenced by vehicle speed, increase by 0.128 if influenced by alcohol. The validation test value with crosstab method explains that the accuracy result of level 1 has an accuracy value of 0.99 and inaccuracy of 0.01 then the result of level 2 to level 5 has an accuracy value of 1
Pemodelan Jumlah Kematian di Jalan Raya Per Satu Juta Penduduk
This study aims to decide the factors that influence Road fatalities per one million inhabitants in member countries of the Organization for Economic Co-operation and Development (OECD). This research data uses a dataset covering 19 member countries of the Organization for Economic Co-operation and Development in 2010 – 2018. This research method uses multivariate analysis with multiple linear regression techniques using several indicators. Nine independent variables are used in this model, namely (X1) road passenger transport in passenger-km per one thousand units of current Gross Domestic Product (GDP) United States Dollar (USD), (X2) road freight transport in tonne-km per one thousand units of current Domestic Product (GDP) United States Dollar (USD), (X3) density of road (km per 100 sq. km), (X4) road transport infrastructure investment in constant United States Dollar (USD) per inhabitant, (X5) goods road motor vehicles per one thousand inhabitants, (X6) motorcycles per one thousand inhabitants, (X7) passenger cars per one thousand inhabitants, (X8) road motor vehicles per one thousand inhabitants, (X9) road traffic in thousand vehicle -km per road motor vehicle. One variable (Y) road fatalities per one million inhabitants, as the dependent variable. The results of the analysis showed that the independent variables had a partial significant effect on road fatalities. From the validation results obtained the value of R² the model is 60%, the F-statistic is 16.03 with a significance value of 0.0000 and the correlation value of the model is 0.66. The resulting multiple regression analysis model is: Y = 69.3071 - 0.0936.X1 + 0.1225X2 + 0.0020X3 - 0.0484X4 + 0.2070X5 + 0.3829X6 - 0.0364X7 -0.0354X8 + 0.0010X
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