1,478 research outputs found
Predicting ride comfort with reclined seats
No full textReclined seats in transport suggest luxury and comfort, but a review of the literature revealed little study of how backrest inclination influences the discomfort caused by vibration of a seat or a backrest. This thesis seeks to advance understanding of the influence of backrest inclination on vibration discomfort and provides a model for evaluating vibration discomfort and metrics for optimising seats with different backrest inclinations.Vibration discomfort depends on the direction and location of vibration input to the body. Subjects used magnitude estimation to judge vibration magnitudes from thresholds of perception up to 2 ms-2 r.m.s. at the 11 preferred 1/3-octave centre frequencies from 2.5 to 25 Hz. The first two experiments determined absolute thresholds and discomfort with x-axis backrest vibration (Experiment 1) and z-axis backrest vibration (Experiment 2) with four backrest inclinations (0°, 30°, 60°, and 90° from vertical). The third experiment investigated discomfort with vertical seat pan vibration and five backrest conditions (no backrest and backrest inclined to 0°, 30°, 60°, and 90°). With x-axis vibration of the back, inclining the backrest had similar effects on thresholds and equivalent comfort contours. Thresholds increased at frequencies from 4 to 8 Hz with increasing inclination of the backrest. With inclined backrests, 40% greater magnitudes of vibration were required from 4 to 8 Hz, to cause discomfort equivalent to that with the upright backrest. Frequency weighting Wc in current standards predicted discomfort and perception of x-axis vibration of the upright backrest (0°) but weighting Wb was more appropriate for inclined backrests. Frequency weighting Wd was appropriate for both discomfort and perception of z-axis vibration of the back at all backrest inclinations. With vertical seat acceleration, the frequency of greatest sensitivity decreased with increasing vibration magnitude. Compared to an upright backrest, around the main resonance of the body the vibration magnitudes required to cause similar discomfort were 100% greater with 60° and 90° backrest inclinations and 50% greater with a 30° backrest inclination.The fourth experiment investigated whole-body vertical vibration on a rigid seat with no backrest and with four backrest inclinations. With an inclined backrest, discomfort caused by high frequency vibration increased at the head or neck but discomfort at the head or neck caused by low frequencies (5 and 6.3 Hz) reduced. With inclined backrests, the procedures in current standards overestimate overall discomfort at frequencies around 5 and 6.3 Hz but underestimate discomfort caused by frequencies greater than about 8 Hz.The final experiment investigated a model for predicting vibration discomfort with three compliant reclined seats. At each frequency, the measured seat dynamic discomfort, MSDD (the ratio of the vibration acceleration required to cause similar discomfort with a compliant seat and a rigid reference seat), was compared with seat effective amplitude transmissibility, SEAT value (the ratio of overall ride values with a compliant seat and a rigid reference seat using the weightings in current standards). The compliant seats increased vibration discomfort at frequencies around the 4-Hz resonance but reduced vibration discomfort at frequencies greater than about 6.3 Hz. The SEAT values provided appropriate indications of how the foam increased vibration discomfort at some frequencies but decreased vibration discomfort at other frequencies. Differences between the SEAT values and the measured seat dynamic discomfort are consistent with the need for different frequency weightings when the body is supported by an inclined backrest.An empirical model was evolved from the experiments for predicting vibration discomfort with reclined seats. It is concluded that reclining a backrest will tend to be detrimental at frequencies greater than about 10 Hz with greater discomfort in the head or neck induced by vibration of the backrest. At frequencies around 5 and 6.3 Hz, reclining a backrest can reduce discomfort
Equivalent comfort contours for whole-body vertical vibration: effect of backrest inclination
No full textThe inclination of a backrest may be expected to alter the vibration transmitted to the body and the associated vibration discomfort. This study examined the influence of backrest inclination on the discomfort arising from whole-body vertical vibration when sitting in a rigid seat with a backrest inclined at 0? (upright), 30?, 60? and 90? (recumbent). Equivalent comfort contours were determined over the frequency range from 1 to 20 Hz and over the magnitude range from 0.2 to 2.0 ms 2 r.m.s. relative to the discomfort caused by 8-Hz vertical vibration at 0.4 ms-2 r.m.s. When sitting with the backrest inclined to 60? or 90?, there was less discomfort around 5 and 6.3 Hz than when sitting with the upright backrest. Around 16 and 20 Hz there was greater discomfort when sitting with the backrest inclined to 30?, 60?, and 90? than when sitting with the upright backrest. The reductions in discomfort at the lower frequencies may be associated with increased postural support and changes in the biodynamic responses of the body when reclined. Increased transmission of vibration to the head may explain the greater discomfort at high frequencies when sitting reclined. It is concluded that different methods of vibration evaluation are appropriate when evaluating vibration with upright and inclined backrests
EVALUATION OF ROAD INTERSECTION ELANG - HASAN BASRI ROAD - WAY ROAD S.PARMAN- ROAD CENDRAWASIH IN SAMARINDA CITY
No full textEvaluation of road intersection Elang – Hasan Basri Road – way Road Priest S.Parman Road – Cendrawasih in Samarinda City Supervisor I : Ir . Yayuk Sri Sundari , MT , and Advisor II : Rosa Agustaniah , ST , MT . Several intersections in the city of Samarinda in particular crossroads Elang – Hasan Basri Road – way Road Priest S.Parman Road – Cendrawasih , necessary to evaluate the performance of traffic lights , because the area is adjacent to the office , school and shops . So at peak hours ( peak hours ) often experience congestion and delays . The purpose of this study is to analyze the performance of traffic lights using Indonesian Highway Capacity Manual 1997 ( MKJI'97 ) at the crossroads Elang – Hasan Basri Road – way Road Priest S.Parman Road – Cendrawasih.The purpose of this study is as follows :1. Knowing the initial conditions of the performance analysis of signalized intersections at peak hours and the service level ( the level of service / LOS )2. Knowing the initial conditions of the performance analysis of signalized intersections at the average and the service level ( the level of service / LOS ) .3. Knowing the analysis of changes in traffic light timing on the performance of signalized intersections at peak hours and service levels ( the level of service / LOS ) . From the analysis of signalized intersections on roads Elang – Hasan Basri Road – way Road Priest S.Parman Road – Cendrawasih in the can ; baseline performance on peak hour intersection level of service ( the level of service / LOS ) initial conditions averaged intersection v / c = 1.208 > 0.85 have a level of service ( LOS ) = F and initial conditions intersection performance at average obtained - service levels ( the level of service / LOS ) initial conditions averaged intersection v / c = 0.913 > 0.85 have a level of service ( LOS ) = E. By the time the change made calculations on the traffic lights at the intersection of performance the level of peak hour services ( level of service / LOS ) initial conditions averaged intersection v / c = 0.741 < 0.85 have this level of service ( LOS ) = C and the change in time of traffic lights at the intersection of the performance of the average rate services ( level of service / LOS ) initial conditions averaged intersection v / c = 0.558 < 0.85 have this level of service ( LOS ) = C.
ANALISIS STRATEGI PENGEMBANGAN SUMBER DAYA MANUSIA UNTUK MENINGKATKAN KINERJA KARYAWAN PADA BAGIAN PELAYANAN BSI KCP HASAN BASRI BANJARMASIN
No full textPenulisan ini bertujuan untuk mengetahui : (1) strategi pengembanga sumber daya manusia pada bagian pelayanan pada Bank Syariah Indonesia (BSI) KCP Hasan Basri Banjarmasin dan (2) meningkatkan kinerja karyawan pada Bank Syariah Indonesia KCP Hasan Basri Banjarmasin. Rencana penelitian ini adalah penelitian kualitatif dengan mengumpulkan data untuk bisa menyelidiki peristiwa atau kejadian-kejadian yang muncul dilapangan lalu dianalisisi dan bisa disimpulkan,penelitian ini menggunakan metode wawancara dan observasi. Hasil penelitian ini menunjukan (1) Strategi Pengembangan Sumber Daya Manusia pada Bagian Pelayanan pada Bank Syariah Indonesia (BSI) KCP Hasan Basri Banjarmasin ini signifikan terhadap penerapan Strategi pengembangan menggunakan metode pelatihan, pengembangan karir dan Refresment Produk terbaru untuk mengembangkan peningktan Sumber Daya Manusia pada Bagian Pelayanan. Dan (2) Meningkatkan kinerja karyawan pada bagian Pelayanan pada Bank Syariah Indonesia (BSI) KCP Hasan Basri Banjarmasin memberikan berbagai upaya yaitu memberikan apresiasi, motiasi, bonus, kenaikan jabatan dan pelatihan, untuk karyawan yang memiliki kinerja yang meningkat
The radiological assessment of axial involvement in psoriatic arthritis: A validation study of the BASRI total and the modified SASSS scoring methods
No full textOBJECTIVES:
To assess the validity of the BASRI and m-SASSS scores for the radiological axial involvement in psoriatic arthritis (PsA). Secondary end-points were to report on clinical, functional and radiographic characteristics of axial involvement.
METHODS:
Inclusion criteria were satisfaction of the CASPAR criteria and the presence of clinical, functional and/or radiological axial involvement. Three observers scored the radiographs by BASRI and m-SASSS. The construct validity was assessed by examining the correlation of instruments with patient reported outcomes and anthropometric measures. The reliability and the feasibility of the scores were also considered.
RESULTS:
Seventy-seven patients were enrolled (58 M, 19 F, mean age 49.4 + or - 10.8 yrs, disease duration 13.9 + or - 7.9 yrs). Both instruments showed some modest but significant correlation with clinical measures. When compared, the BASRI showed a correlation with BASMI (rho=0.47, p<0.001), cervical rotation (rho=-0.49, p<0.001), tragus to wall (rho=0.34, p<0.01) and occiput to wall (rho=0.49, p<0.001), modified Schober test (rho=-0.24, p<0.05) and RLDQ (rho=-0.24, p<0.05). When compared, m-SASSS showed a correlation with BASMI (rho=0.39, p<0.001), cervical rotation (rho=-0.41, p<0.001), tragus to wall (rho=0.31, p<0.01) and occiput to wall (rho=0.42, p<0.001), modified Schober and Schober test (rho=-0.34, p<0.001; rho= -0.32, p<0.01), finger to floor (rho=0.37, p<0.01). No correlation was found with BASFI, BASDAI and HAQ. Test-retest showed a good reliability of the scores. Both were feasible but BASRI was the quickest.
CONCLUSION:
Our results showed that BASRI and m-SASSS were valid instruments for use in spondylitis associated with psoriatic arthritis. Longitudinal data is required to provide sensitivity to change of the two scores
Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs
No full textWe present results from a high-resolution spectroscopic survey of 45 L dwarfs, which includes both very low mass stars and brown dwarfs. Our spectra allow us to derive a significant number of new rotational velocities, and discover a slowly rotating (in projected velocity) L dwarf that allows more accurate measurement of spectroscopic rotations for these objects. We measure chromospheric activity (and often its variability) through the H alpha emission line. Our primary new result is good evidence that magnetic braking dominates the angular momentum evolution of even brown dwarfs, although spindown times appear to increase as mass decreases. We confirm that activity decreases as effective temperature decreases, although a larger fraction of L dwarfs are active than has previously been reported. Essentially all active objects are also variable. We confirm the lack of a rotation-activity connection for L dwarfs. We find a minimum limit for rotational velocities that increases with later spectral types, rising from near zero in older mid-M stars to more than 20 km s(-1) for mid-L objects. There is strong evidence that all L dwarfs are rapid rotators. We derive a braking law that can depend on either temperature or mass which can explain all the rotational results and provides an age dependence for the angular momentum evolution. It is clear that angular momentum loss mechanisms in smaller and cooler objects become more inefficient, starting at the fully convective boundary
The radiological assessment of axial involvement in psoriatic arthritis: a validation study of the BASRI total and the modified SASSS scoring methods
No full textTo assess the validity of the BASRI and m-SASSS scores for the radiological axial involvement in psoriatic arthritis (PsA). Secondary end-points were to report on clinical, functional and radiographic characteristics of axial involvement
A VOLUME-LIMITED SAMPLE OF 63 M7-M9.5 DWARFS. II. ACTIVITY, MAGNETISM, AND THE FADE OF THE ROTATION-DOMINATED DYNAMO
No full textIn a volume-limited sample of 63 ultracool dwarfs of spectral type M7-M9.5, we have obtained high-resolution spectroscopy with UVES at the Very Large Telescope and HIRES at Keck Observatory. In this second paper, we present projected rotation velocities, average magnetic field strengths, and chromospheric emission from the H alpha line. We confirm earlier results that the mean level of normalized H alpha luminosity decreases with lower temperature, and we find that the scatter among H alpha luminosities is larger at lower temperature. We measure average magnetic fields between 0 and 4 kG with no indication for a dependence on temperature between M7 and M9.5. For a given temperature, H alpha luminosity is related to magnetic field strength, consistent with results in earlier stars. A few very slowly rotating stars show very weak magnetic fields and H alpha emission, and all stars rotating faster than our detection limit show magnetic fields of at least a few hundred Gauss. In contrast to earlier-type stars, we observe magnetic fields weaker than 1 kG in stars rotating faster than similar to 3 km s(-1), but we find no correlation between rotation and magnetic flux generation among them. We interpret this as a fundamental change in the dynamo mechanism; in ultracool dwarfs, magnetic field generation is predominantly achieved by a turbulent dynamo, while other mechanisms can operate more efficiently at earlier spectral types.DFG [RE 1664/4-1]; NSF [AST06-06748
The vibration of inclined backrests: perception and discomfort of vibration applied normal to the back in the x-axis of the body
No full textThe vibration of backrests contributes to the discomfort of drivers and passengers. A frequency weighting exists for evaluating the vibration of vertical backrests but not for reclined backrests often used during travel. This experimental study was designed to determine how backrest inclination and the frequency of vibration influence perception thresholds and vibration discomfort when the vibration is applied normal to the back (i.e. fore-and-aft vibration when seated upright and vertical vibration when fully reclined). Twelve subjects experienced the vibration of a backrest (at each of the 11 preferred one-third octave centre frequencies in the range 2.5–25 Hz) at vibration magnitudes from the threshold of perception to 24 dB above threshold. Initially, absolute thresholds for the perception of vibration were determined with four backrest inclinations: 0° (upright), 30°, 60° and 90° (recumbent). The method of magnitude estimation was then used to obtain judgements of vibration discomfort with each of the four backrest angles. Finally, the relative discomfort between the four backrest angles, and the principal locations for feeling vibration discomfort in the body, were determined. With all backrest inclinations, absolute thresholds for the perception of vibration acceleration were dependent on the frequency of vibration. As the backrest inclination became more horizontal, the thresholds increased at frequencies between 4 and 8 Hz. For all backrest inclinations, the rate of growth of discomfort with increasing magnitude of vibration was independent of the frequency of vibration, so the frequency-dependence of discomfort was similar over the range of magnitudes investigated (0.04–0.6 m s?2 rms). With an upright backrest, the discomfort caused by vibration acceleration tended to be greatest at frequencies less than about 8 Hz. With inclined backrests (at 30°, 60°, and 90°), the equivalent comfort contours were broadly similar to each other, with greatest discomfort caused by acceleration around 10 or 12.5 Hz. At frequencies from 4 to 8 Hz, 30–40 percent greater magnitudes of vibration were required with the three inclined backrests to cause discomfort equivalent to that caused by the upright backrest. It is concluded that with an upright backrest the frequency weighting Wc used in current standards is appropriate for predicting the discomfort caused by fore-and-aft backrest vibration. With inclined and horizontal backrests, a weighting similar to frequency weighting Wb (used to predict discomfort caused by vertical seat vibration) appears more appropriate
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