A PERIODIC MAINTENANCE OF CONNECTED-(r, s)-OUT-OF-(m,n): F SYSTEM WITH FAILURE DEPENDENCE

Yun, Won Young; Jeong, Cheol Hun; Kim, Gui Rae; Yamamoto, Hisashi

doi:10.1142/9789812702685_0076

Cited by 3 publications

(4 citation statements)

References 3 publications

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“…While the colours of our target HzRGs are marginally consistent with colours expected of active galaxies, those detected by AzTEC (filled squares) appear near the edges of the distribution, along the model tracks of young dust‐obscured stellar clusters modelled by Efstathiou et al (2000). This is also the area where the majority of submillimetre‐bright sources are clustered (Yun et al 2008, 2011), and these AzTEC‐detected HzRGs display rest‐frame near‐IR properties more like SMGs than other HzRGs.…”

Section: Analysis Of the Mid‐ir Spectral Energy Distributionsupporting

confidence: 64%

AzTEC 1.1-mm images of 16 radio galaxies at 0.5 < z < 5.2 and a quasar at z= 6.3

Humphrey

Zeballos

Aretxaga

et al. 2011

Monthly Notices of the Royal Astronomical Society

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We present 1.1-mm observations for a sample of 16 powerful radio galaxies at 0.5 < z < 5.2 and a radio-quiet quasar at z = 6.3, obtained using the AzTEC bolometer array mounted on the Atacama Submillimetre Telescope Experiment (ASTE) or the James Clerk Maxwell Telescope (JCMT). This paper more than doubles the number of high-z radio galaxies imaged at millimetre/submillimetre wavelengths. We detect probable millimetre-wave counterparts for 11 of the active galaxies. The six active galaxies that do not have a probable millimetre counterpart in our images nevertheless have one or more likely associated millimetric source. Thus, we conclude that powerful (radio-loud) active galaxies at high-z are beacons for finding luminous millimetre/submillimetre galaxies at high-z. The flux densities of our AzTEC counterparts imply star formation rates ranging from <200 to ∼1300 M yr −1 . In addition, we find that for the radio galaxies the 1.1-mm flux density is anticorrelated with the largest angular size of the radio source.We also present new Spitzer imaging observations of several active galaxies in our sample. Combining these with archival data, we examine the mid-infrared colours of our sample. We find that radio galaxies for which we have detected a probable 1.1-mm counterpart have mid-infrared colours consistent with dusty starbursts, and are usually bluer than high-z Spitzerselected active galaxies. In addition, we find arcs of 24-µm sources extending across ∼200-500 kpc, apparently associated with three of the radio galaxies.

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Section: Analysis Of the Mid‐ir Spectral Energy Distributionsupporting

confidence: 64%

AzTEC 1.1-mm images of 16 radio galaxies at 0.5 < z < 5.2 and a quasar at z= 6.3

Humphrey

Zeballos

Aretxaga

et al. 2011

Monthly Notices of the Royal Astronomical Society

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“…To put this result into context, we now aim to discuss the L ′ CO -L FIR relation and its implications for some selected samples of galaxies at low and high redshift. Figure 5 shows the relationship between log(L FIR ) and log(L ′ CO ) for our three targets, all other high-z CO detections (except TN J0924-2201, which does not have a measured FIR luminosity), the z < 0.2 Palomar-Green (PG) QSOs from Alloin et al (1992), Evans et al (2001), and Scoville et al (2003) including PDS 456 (Yun et al 2004), local (z < 0.3) ULIRGs from Solomon et al (1997), and the local galaxy sample (z < 0.1) of Gao & Solomon (2004). All FIR luminosities for the highz sources are re-derived as described by Carilli et al (2005) unless stated otherwise.…”

Section: 2mentioning

confidence: 97%

“…5). As the relative number of such outliers is very small, this may also be explained by a brief FIR-bright AGN phase (Yun et al 2004). However, it is likely that the dominant energy source in most ULIRGs is an extreme starburst rather than heating by a dust-enshrouded AGN (e.g., Solomon et al 1997;Downes & Solomon 1998).…”

Section: 2mentioning

confidence: 99%

CO(1–0) inz≳ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs

Riechers

Walter

Carilli

et al. 2006

ApJ

173

231

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We present 12 CO(J=1→0) observations of the high-redshift quasi-stellar objects (QSOs) BR 1202-0725 (z = 4.69), PSS J2322+1944 (z = 4.12), and APM 08279+5255 (z = 3.91) using the NRAO Green Bank Telescope (GBT) and the MPIfR Effelsberg 100 m telescope. We detect, for the first time, the CO ground-level transition in BR 1202-0725. For PSS J2322+1944 and APM 08279+5255, our observations result in line fluxes that are consistent with previous NRAO Very Large Array (VLA) observations, but they reveal the full line profiles. We report a typical lensing-corrected velocity-integrated intrinsic 12 CO(J=1→0) line luminosity of L ′ CO = 5 × 10 10 K km s −1 pc 2 and a typical total H 2 mass of M (H 2 ) = 4 × 10 10 M ⊙ for the sources in our sample. The CO/FIR luminosity ratios of these high-z sources follow the same trend as seen for low-z galaxies, leading to a combined solution of log(L FIR ) = (1.39 ± 0.05) × log(L CO ) − 1.76. It has previously been suggested that the molecular gas reservoirs in some quasar host galaxies may exhibit luminous, extended 12 CO(J=1→0) components that are not observed in the higher-J CO transitions. Utilizing the line profiles and the total intensities of our observations and large velocity gradient (LVG) models based on previous results for higher-J CO transitions, we derive that emission from all CO transitions is described well by a single gas component where all molecular gas is concentrated in a compact nuclear region. Thus, our observations and models show no indication of a luminous extended, low surface brightness molecular gas component in any of the high-redshift QSOs in our sample. If such extended components exist, their contribution to the overall luminosity is limited to at most 30%.

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“…The system fails, if there is at least one grid of r rows and s columns of which all components are failed (1 4 r 4 m, 1 4 s 4 n). Yun et al 13,14 studied a system design optimization problem in connected-(r, s)-out-of-(m, n): F systems with identical and independent components, where the model parameters (r, s) are decision variables. Yun et al 15 estimated the system reliability of the linear consecutive-(r, s)-out-of-(m, n): F lattice system with failure dependence by simulation and proposed a PM policy based on age.…”

Section: Introductionmentioning

confidence: 99%

A preventive replacement policy based on system critical condition

Yun

Endharta

2015

Proceedings of the Institution of Mechanical Engineers, Part O:

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The article considers a linear consecutive-k-out-of-n: F system and a linear connected-(r, s)-out-of-(m, n): F system. It is assumed that the components are identical and the failure times of components follow an exponential distribution. The system is continuously monitored and the component failure can be known at any time. A preventive maintenance policy is proposed, and it is based on the system critical condition which is related to the number of working components in the minimal cut sets of the system. If there is at least one minimal cut set which consists of only one working component, the system is maintained preventively after a certain time interval and the failed components are replaced with the new ones to prevent the system failures. The expected cost rate is used as an optimization criterion. The expected cost rate is estimated by simulation and numerical examples are studied. The numerical analyses are exploratory and not generalizable.

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A PERIODIC MAINTENANCE OF CONNECTED-(r, s)-OUT-OF-(m,n): F SYSTEM WITH FAILURE DEPENDENCE

Cited by 3 publications

References 3 publications

AzTEC 1.1-mm images of 16 radio galaxies at 0.5 < z < 5.2 and a quasar at z= 6.3

AzTEC 1.1-mm images of 16 radio galaxies at 0.5 < z < 5.2 and a quasar at z= 6.3

CO(1–0) inz≳ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs

A preventive replacement policy based on system critical condition

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