Brandon Shim - Academia.edu (original) (raw)

Papers by Brandon Shim

Research paper thumbnail of Compensation and Comparable Worth: What Lies Ahead for California's Preschool Teachers? CENTER FOR THE STUDY OF CHILD CARE EMPLOYMENT

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Research paper thumbnail of Piecewise-affine control of a three DOF helicopter

This paper develops a piecewise-affine (PWA) controller for a nonlinear three degree of freedom (... more This paper develops a piecewise-affine (PWA) controller for a nonlinear three degree of freedom (DDF) helicopter model. To design this controller a local linear controller is designed for a PWA approximation of the model in the region where the desired closed-loop equilibrium point lies. An optimization problem subject to bilinear matrix inequalities (BMIs) is then solved to find a PWA

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Research paper thumbnail of Structure, mineralogy and dynamics of the lowermost mantle

Mineralogy and Petrology, 2010

The 2004-discovery of the post-perovskite transition initiated a vigorous effort in high-pressure... more The 2004-discovery of the post-perovskite transition initiated a vigorous effort in high-pressure, high-temperature mineralogy and mineral physics, seismology and geodynamics aimed at an improved understanding of the structure and dynamics of the D"-zone. The phase transitions in basaltic and peridotitic lithologies under pT-conditions of the lowermost mantle can explain a series of previously enigmatic seismic discontinuities. Some of the other seismic properties of the lowermost mantle are also consistent with the changes in physical properties related to the perovskite (pv) to post-perovskite (ppv) transition. After more than 25 years of seismic tomography, the lowermost mantle structure involving the sub-Pacific and sub-African Large Low Shear-Velocity Provinces (LLSVPs) has become a robust feature. The two large antipodal LLSVPs are surrounded by wide zones of high Vs under the regions characterized by Mesozoic to recent subduction. The D" is further characterized by a negative correlation between shear and bulk sound velocity which could be partly related to an uneven distribution of pv and ppv. Ppv has higher VS and lower \( V_{\Phi } \) (bulk sound speed) than pv and may be present in thicker layers in the colder regions of D". Seismic observations and geodynamic modelling indicate relatively steep and sharp boundaries of the 200-500 km thick LLSVPs. These features, as well as independent evidence for their long-term stability, indicate that they are intrinsically denser than the surrounding mantle. Mineral physics data demonstrate that basaltic lithologies are denser than peridotite throughout the lowermost mantle and undergo incremental densification due to the pvppv- transition at slightly shallower levels than peridotite. The density contrasts may facilitate the partial separation and accumulation of basaltic patches and slivers at the margins of the thermochemical piles (LLSVPs). The slopes of these relatively steep margins towards the adjacent horizontal core-mantle boundary (CMB) constitute a curved (concave) thermal boundary layer, favourable for the episodic generation of large mantle plumes. Reconstruction of the original positions of large igneous provinces formed during the last 300 Ma, using a paleomagnetic global reference frame, indicates that nearly all of them erupted above the margins of the LLSVPs. Fe/Mg-partitioning between pv, ppv and ferropericlase (fp) is important for the phase and density relations of the lower mantle. Electronic spin transition of Fe2+ and Fe3+ in the different phases may influence the Fe/Mg-partitioning and the radiative thermal conductivity in the lowermost mantle. The experimental determination of the \( {K_D}{^{Fe/Mg}_{pv/fp}}\left[ { = {{\left( {Fe/Mg} \right)}_{pv}}/{{\left( {Fe/Mg} \right)}_{fp}}} \right] \) and \( {K_D}{^{Fe/Mg}_{ppv/fp}} \) is technologically challenging. Most studies have found a \( {K_D}{^{Fe/Mg}_{pv/fp}} \) of 0.1-0.3 and a higher Fe/Mg-ratio in ppv than in pv. The experimental temperature is important, with the partitioning approaching unity with increasing temperature. Although charge-coupled substitutions of the trivalent cations Al and Fe3+ seem to be important in both pv and ppv (especially in basaltic compositions), the complicating crystal-chemistry effects of these cations are not fully clarified. The two anti-podal thermochemical piles as well as the thin ultra-low velocity zones next to the CMB may represent geochemically enriched reservoirs that have remained largely isolated from the convecting mantle through a major part of Earth history. The existence of such “hidden” reservoirs have previously been suggested in order to account for the imbalance between the inferred composition of the geochemically accessible convecting mantle and the observed heat flow from the Earth and chondritic models for the bulk Earth.

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Research paper thumbnail of STRENGTH FACTORS RELATED TO MAXIMAL POWER OUTPUT DURING JUMP SQUATS WITH AN OPTIMAL LOAD

Medicine and Science in Sports and Exercise, 2002

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Research paper thumbnail of THE INFLUENCE OF LOWER-BODY COMPRESSION GARMENTS ON ATHLETIC PERFORMANCE

Medicine and Science in Sports and Exercise, 2001

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Research paper thumbnail of RELATIONSHIP OF 1 RM SQUAT AND VERTICAL JUMP PERFORMANCE IN NCAA MALE VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2002

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Research paper thumbnail of Evaluation of a lower-body compression garment

Journal of Sports Sciences, 2003

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Research paper thumbnail of EFFECTS OF IN-SEASON STRENGTH AND POWER TRAINING ON SQUAT JUMP PERFORMANCE IN NCAA WOMEN VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2001

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Research paper thumbnail of Determination of Functional Strength Imbalance of the Lower Extremities

Journal of Strength and Conditioning Research, 2006

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Research paper thumbnail of DIAGNOSIS OF VERTICAL COUNTERMOVEMENT JUMP PERFORMANCE IN NCAA VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2001

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Research paper thumbnail of Compensation and Comparable Worth: What Lies Ahead for California's Preschool Teachers? CENTER FOR THE STUDY OF CHILD CARE EMPLOYMENT

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Research paper thumbnail of Piecewise-affine control of a three DOF helicopter

This paper develops a piecewise-affine (PWA) controller for a nonlinear three degree of freedom (... more This paper develops a piecewise-affine (PWA) controller for a nonlinear three degree of freedom (DDF) helicopter model. To design this controller a local linear controller is designed for a PWA approximation of the model in the region where the desired closed-loop equilibrium point lies. An optimization problem subject to bilinear matrix inequalities (BMIs) is then solved to find a PWA

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Research paper thumbnail of Structure, mineralogy and dynamics of the lowermost mantle

Mineralogy and Petrology, 2010

The 2004-discovery of the post-perovskite transition initiated a vigorous effort in high-pressure... more The 2004-discovery of the post-perovskite transition initiated a vigorous effort in high-pressure, high-temperature mineralogy and mineral physics, seismology and geodynamics aimed at an improved understanding of the structure and dynamics of the D"-zone. The phase transitions in basaltic and peridotitic lithologies under pT-conditions of the lowermost mantle can explain a series of previously enigmatic seismic discontinuities. Some of the other seismic properties of the lowermost mantle are also consistent with the changes in physical properties related to the perovskite (pv) to post-perovskite (ppv) transition. After more than 25 years of seismic tomography, the lowermost mantle structure involving the sub-Pacific and sub-African Large Low Shear-Velocity Provinces (LLSVPs) has become a robust feature. The two large antipodal LLSVPs are surrounded by wide zones of high Vs under the regions characterized by Mesozoic to recent subduction. The D" is further characterized by a negative correlation between shear and bulk sound velocity which could be partly related to an uneven distribution of pv and ppv. Ppv has higher VS and lower \( V_{\Phi } \) (bulk sound speed) than pv and may be present in thicker layers in the colder regions of D". Seismic observations and geodynamic modelling indicate relatively steep and sharp boundaries of the 200-500 km thick LLSVPs. These features, as well as independent evidence for their long-term stability, indicate that they are intrinsically denser than the surrounding mantle. Mineral physics data demonstrate that basaltic lithologies are denser than peridotite throughout the lowermost mantle and undergo incremental densification due to the pvppv- transition at slightly shallower levels than peridotite. The density contrasts may facilitate the partial separation and accumulation of basaltic patches and slivers at the margins of the thermochemical piles (LLSVPs). The slopes of these relatively steep margins towards the adjacent horizontal core-mantle boundary (CMB) constitute a curved (concave) thermal boundary layer, favourable for the episodic generation of large mantle plumes. Reconstruction of the original positions of large igneous provinces formed during the last 300 Ma, using a paleomagnetic global reference frame, indicates that nearly all of them erupted above the margins of the LLSVPs. Fe/Mg-partitioning between pv, ppv and ferropericlase (fp) is important for the phase and density relations of the lower mantle. Electronic spin transition of Fe2+ and Fe3+ in the different phases may influence the Fe/Mg-partitioning and the radiative thermal conductivity in the lowermost mantle. The experimental determination of the \( {K_D}{^{Fe/Mg}_{pv/fp}}\left[ { = {{\left( {Fe/Mg} \right)}_{pv}}/{{\left( {Fe/Mg} \right)}_{fp}}} \right] \) and \( {K_D}{^{Fe/Mg}_{ppv/fp}} \) is technologically challenging. Most studies have found a \( {K_D}{^{Fe/Mg}_{pv/fp}} \) of 0.1-0.3 and a higher Fe/Mg-ratio in ppv than in pv. The experimental temperature is important, with the partitioning approaching unity with increasing temperature. Although charge-coupled substitutions of the trivalent cations Al and Fe3+ seem to be important in both pv and ppv (especially in basaltic compositions), the complicating crystal-chemistry effects of these cations are not fully clarified. The two anti-podal thermochemical piles as well as the thin ultra-low velocity zones next to the CMB may represent geochemically enriched reservoirs that have remained largely isolated from the convecting mantle through a major part of Earth history. The existence of such “hidden” reservoirs have previously been suggested in order to account for the imbalance between the inferred composition of the geochemically accessible convecting mantle and the observed heat flow from the Earth and chondritic models for the bulk Earth.

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Research paper thumbnail of STRENGTH FACTORS RELATED TO MAXIMAL POWER OUTPUT DURING JUMP SQUATS WITH AN OPTIMAL LOAD

Medicine and Science in Sports and Exercise, 2002

Bookmarks Related papers MentionsView impact

Research paper thumbnail of THE INFLUENCE OF LOWER-BODY COMPRESSION GARMENTS ON ATHLETIC PERFORMANCE

Medicine and Science in Sports and Exercise, 2001

Bookmarks Related papers MentionsView impact

Research paper thumbnail of RELATIONSHIP OF 1 RM SQUAT AND VERTICAL JUMP PERFORMANCE IN NCAA MALE VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2002

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluation of a lower-body compression garment

Journal of Sports Sciences, 2003

Bookmarks Related papers MentionsView impact

Research paper thumbnail of EFFECTS OF IN-SEASON STRENGTH AND POWER TRAINING ON SQUAT JUMP PERFORMANCE IN NCAA WOMEN VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2001

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Research paper thumbnail of Determination of Functional Strength Imbalance of the Lower Extremities

Journal of Strength and Conditioning Research, 2006

Bookmarks Related papers MentionsView impact

Research paper thumbnail of DIAGNOSIS OF VERTICAL COUNTERMOVEMENT JUMP PERFORMANCE IN NCAA VOLLEYBALL PLAYERS

Medicine and Science in Sports and Exercise, 2001

Bookmarks Related papers MentionsView impact