Lateral Torsional Buckling Strengths of Stepped Beams at Midspan Exposed to Elevated Temperature

Shane Alolod,박종섭,원덕희 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.6

The American Institute of Steel Construction provides design equations for the lateral torsional buckling (LTB) of beams under fi re. However, these equations are limited only to prismatic beams. Stepped beam factors are introduced by researchers that accounts the change in cross-sections of beams to determine capacities of stepped beams under normal temperatures. This paper assesses the validity of the stepped beam factors for the LTB capacities of stepped I-beams located at its midspans integrated to the AISC equation for beams under high temperatures. A set of numerical studies using fi nite element analysis program, ABAQUS, was conducted to assess the buckling behavior of stepped beams. The analysis is composed of heattransfer analysis that evaluates the change in material properties of steel as heat propagates the material from 20 °C to 800 °C; and Static Riks analysis where the beams are applied with uniform end moments. Correlation between the results from the stepped beam equations and the simulated data from ABAQUS has been done. The comparison between data showed that the proposed equation generated conservative estimates with an average percentage diff erence of 11.48% for inelastic LTB, whilst, 2.07% for the elastic LTB. In addition, the ratio of the increase in strength and increase in volume of stepping of beams shows that the fl ange width of the stepped beam controls its effi ciency in lateral torsional buckling capacity. Overall, the results of this research proved that the existing stepped beam equations can be used in calculating the structural capacity of stepped beams at midspan under both normal and elevated temperatures.

Investigation of Thermal Behaviour of a Hybrid Precasted Concrete Floor using Embedded Sensors

Shane Newell,Jamie Goggins 한국콘크리트학회 2018 International Journal of Concrete Structures and M Vol.12 No.7

Concrete structures expand and contract in response to temperature changes which can result in structural strain and cracking. However, there is a limited amount of robust field data on hybrid concrete floor structures. Shortage of such data impacts on our understanding of how concrete structures respond to thermal effects and ultimately the overall design of concrete structures. Thus, a comprehensive structural and environmental monitoring strategy was implemented by the authors during the construction of an educational building. Sensors were embedded in the precast and in situ components of a hybrid concrete lattice girder flat slab so that the thermal response of the floor during the manufacture, construction and operational stages could be investigated. Many aspects of the thermal behaviour of the floor during the construction phase were monitored using the embedded sensors. The early-age thermal effects during curing and the impact of the variation of ambient temperature (daily and seasonal) and solar radiation on the behaviour of concrete floor is explored in the paper. Values for restraint factors and the in situ restrained coefficient of thermal expansion of concrete are calculated using the data from the embedded sensors. Numerical modelling of the thermal behaviour of the hybrid concrete floor was undertaken and validated using the real-time field measurements. The data presented and analysed in this paper can be used to improve the understanding and modelling of the thermal behaviour of a hybrid concrete floor. This will assist with improved design of sustainable buildings as it allows the environmental performance of the floor to be optimised with respect to controlling the internal environment, thermal mass and energy efficiency.

A lumped parameter method of characteristics approach and multigroup kernels applied to the subgroup self-shielding calculation in MPACT

Shane Stimpson,Yuxuan Liu,Benjamin Collins,Kevin Clarno 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.6

An essential component of the neutron transport solver is the resonance self-shielding calculation used to determine equivalence cross sections. The neutron transport code, MPACT, is currently using the subgroup self-shielding method, in which the method of characteristics (MOC) is used to solve purely absorbing fixed-source problems. Recent efforts incorporating multigroup kernels to the MOC solvers in MPACT have reduced runtime by roughly 2×. Applying the same concepts for self-shielding and developing a novel lumped parameter approach to MOC, substantial improvements have also been made to the self-shielding computational efficiency without sacrificing any accuracy. These new multigroup and lumped parameter capabilities have been demonstrated on two test cases: (1) a single lattice with quarter symmetry known as VERA (Virtual Environment for Reactor Applications) Progression Problem 2a and (2) a two-dimensional quarter-core slice known as Problem 5a-2D. From these cases, self-shielding computational time was reduced by roughly 3-4×, with a corresponding 15-20% increase in overall memory burden. An azimuthal angle sensitivity study also shows that only half as many angles are needed, yielding an additional speedup of 2×. In total, the improvements yield roughly a 7-8× speedup. Given these performance benefits, these approaches have been adopted as the default in MPACT.

Further results on biases in integer partitions

Shane Chern 대한수학회 2022 대한수학회보 Vol.59 No.1

Let $p_{a,b,m}(n)$ be the number of integer partitions of $n$ with more parts congruent to $a$ modulo $m$ than parts congruent to $b$ modulo $m$. We prove that $p_{a,b,m}(n)\ge p_{b,a,m}(n)$ whenever $1\le a<b\le m$. We also propose some conjectures concerning series with nonnegative coefficients in their expansions.

The Deep Inferior Epigastric Perforator and Pedicled Transverse Rectus Abdominis Myocutaneous Flap in Breast Reconstruction: A Comparative Study

Shane Tan,Jacklyn Yek,Wei Chen Ong,Chor Hoong Hing,Jane LIM,Thiam Chye LIM 대한성형외과학회 2013 Archives of Plastic Surgery Vol.40 No.3

Background Our objective was to compare the complication rates of two common breast reconstruction techniques performed at our hospital and the cost-effectiveness for each test group. Methods All patients who underwent deep inferior epigastric perforator (DIEP) flap and transverse rectus abdominis myocutaneous (TRAM) flap by the same surgeon were selected and matched according to age and mastectomy with or without axillary clearance. Patients from each resultant group were selected, with the patients matched chronologically. The remainder were matched for by co-morbidities. Sixteen patients who underwent immediate breast reconstruction with pedicled TRAM flaps and 16 patients with DIEP flaps from 1999to 2006 were accrued. The average total hospitalisation cost, length of hospitalisation, and complications in the 2 year duration after surgery for each group were compared. Results Complications arising from both the pedicled TRAM flaps and DIEP flaps included fat necrosis (TRAM, 3/16; DIEP, 4/16) and other minor complications (TRAM, 3/16; DIEP, 1/16). The mean hospital stay was 7.13 days (range, 4 to 12 days) for the pedicled TRAM group and 7.56 (range, 5 to 10 days) for the DIEP group. Neither the difference in complication rates nor in hospital stay duration were statistically significant. The total hospitalisation cost for the DIEP group was significantly higher than that of the pedicled TRAM group (P<0.001). Conclusions Based on our study, the pedicled TRAM flap remains a cost-effective technique in breast reconstruction when compared to the newer, more expensive and tedious DIEP flap

Advanced peri-implantitis cases with radical surgical treatment

Shane J.J. McCrea 대한치주과학회 2014 Journal of Periodontal & Implant Science Vol.44 No.1

Purpose: Peri-implantitis, a clinical term describing the inflammatory process that affectsthe soft and hard tissues around an osseointegrated implant, may lead to peri-implantpocket formation and loss of supporting bone. However, this imprecise definition has resultedin a wide variation of the reported prevalence; ≥10% of implants and 20% of patientsover a 5- to 10-year period after implantation has been reported. The individual reportingof bone loss, bleeding on probing, pocket probing depth and inconsistent recordingof results has led to this variation in the prevalence. Thus, a specific definition of peri-implantitisis needed. This paper describes the vast variation existing in the definition of periimplantitisand suggests a logical way to record the degree and prevalence of the condition. The evaluation of bone loss must be made within the concept of natural physiologicalbony remodelling according to the initial peri-implant hard and soft tissue damage and actualdefinitive load of the implant. Therefore, the reason for bone loss must be determinedas either a result of the individual osseous remodelling process or a response to infection. Methods: The most current Papers and Consensus of Opinion describing peri-implantitisare presented to illustrate the dilemma that periodontologists and implant surgeons arefaced with when diagnosing the degree of the disease process and the necessary treatmentregime that will be required. Results: The treatment of peri-implantitis should be determined by its severity. A case ofadvanced peri-implantitis is at risk of extreme implant exposure that results in a loss ofsoft tissue morphology and keratinized gingival tissue. Conclusions: Loss of bone at the implant surface may lead to loss of bone at any adjacentnatural teeth or implants. Thus, if early detection of peri-implantitis has not occurred andthe disease process progresses to advanced peri-implantitis, the compromised hard andsoft tissues will require extensive, skill-sensitive regenerative procedures, including implantotomy,established periodontal regenerative techniques and alternative osteotomy sites.

Calculation of water droplet impingement using the coupled method of rigid body dynamics and the moving particle semi-implicit method

Shane Park,전규동 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.11

When a liquid droplet impacts on a solid surface, it recoils to the center of that surface after reaching its maximum spreading diameter. The mechanism of droplet recoiling is not fully understood. To simulate this recoiling of a droplet, a particle method is a good choice because it does not require grids for simulating fluid motions, and can easily handle a large deformation of fluid. In this study, the coupled method of rigid body dynamics and the moving particle semi-implicit (MPS) method (Park and Jeun, 2011) was used to calculate three-dimensional droplet impingement. Also, the previous surface tension model for MPS (Nomura et al., 2001) was revised to get a more realistic surface tension force. A two-step calculation was performed. In the first step, a MPS calculation was performed with particles that were considered to have no mass or volume. In the second step, rigid body dynamics came into the calculation and considered the diameters of particles being slightly lesser than the initial distance between particles. In this study, the calculated results were compared with the measured data (Kim and Chun, 2000) and the recoiling lengths of droplets for the various initial impingement speeds were estimated.

SπRIT: A time-projection chamber for symmetry-energy studies

Shane, R.,McIntosh, A.B.,Isobe, T.,Lynch, W.G.,Baba, H.,Barney, J.,Chajecki, Z.,Chartier, M.,Estee, J.,Famiano, M.,Hong, B.,Ieki, K.,Jhang, G.,Lemmon, R.,Lu, F.,Murakami, T.,Nakatsuka, N.,Nishimura, M Elsevier 2015 Nuclear Instruments & Methods in Physics Research. Vol.784 No.-

<P><B>Abstract</B></P> <P>A time-projection chamber (TPC) called the SAMURAI Pion-Reconstruction and Ion-Tracker (SπRIT) has recently been constructed at Michigan State University as part of an international effort to constrain the symmetry-energy term in the nuclear Equation of State (EoS). The SπRIT TPC will be used in conjunction with the SAMURAI spectrometer at the Radioactive Isotope Beam Factory (RIBF) at RIKEN to measure yield ratios for pions and other light isospin multiplets produced in central collisions of neutron-rich heavy ions, such as <SUP>132</SUP>Sn+<SUP>124</SUP>Sn. The SπRIT TPC can function both as a TPC detector and as an active target. It has a vertical drift length of 50cm, parallel to the magnetic field. Gas multiplication is achieved through the use of a multi-wire anode plane. Image charges, produced in the 12096 pads, are read out with the recently developed Generic Electronics for TPCs.</P>

Managing eWOM for hotel performance

Shane Mathews,Catherine Prentice,Alice Tsou,Clinton Weeks,Lisa Tam,Edwina Luck 한국마케팅과학회 2022 마케팅과학연구 Vol.32 No.3

Electronic word-of-mouth (eWOM) is an important marketing tool for achieving positive customer-related outcomes and firm performance. However, eWOM management is not well understood. This study explores how eWOM management can be utilized to optimize firm performance. Using a multiple case study approach, indepth interviews were conducted with senior managers who were involved in the management of eWOM from nine hotels, and their websites and marketing materials were analyzed. eWoM digital platforms give even resource-constrained smaller hotels timely review analytics that can be used for the purpose of brand reputation strategy decisions. That is, those hotels that focus their limited resources on developing authentic response systems and create unique communication capabilities which are leveraged for eWOM reputation as a competitive advantage. These findings highlight that successful hotels use eWoM data analytics for decisions related long-term signaling strategies: as hotels can extend their authentic voice or an organizational character within their eWOM responses over time to complement their optimal brand position.

Auckland and Jeju Volcanic Centre sister-volcano research project; Understanding hazard and risk at monogenetic volcanic systems

Shane J. Cronin,Y.K. Sohn,I.E.M. Smith,K. N?meth,K.H. Park,G.W. Koh,M. Bebbington,M. Brenna 대한지질학회 2009 대한지질학회 학술대회 Vol.2009 No.