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81.
Rhee T Lewis JP Neumann U Nayak KS 《IEEE transactions on visualization and computer graphics》2011,17(3):368-379
This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the nonlinear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion-free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries. 相似文献
82.
This paper proposes an efficient multiuser adaptive modulation and coding (AMC) scheme that considers inevitable feedback delay by employing short-term and long-term channel state information (CSI) in time-varying frequency-selective fading channels. By taking the statistic of the true signal-to-noise ratio (SNR) at a given predicted SNR value into account, the required transmit power to meet the target packet-error-rate (PER) can be obtained and used for user selection, power allocation, and modulation and coding set (MCS) selection. In addition, a simple and useful approximation method of obtaining the required transmit power is proposed. The performance of the proposed scheme is shown to be much better than that of conventional schemes without considering the feedback delay or the prediction error. The proposed scheme can also reduce the feedback resource while maintaining the system throughput by allocating different feedback resources to different users according to their prediction error variances. 相似文献
83.
K.Y. Rhee 《Composite Structures》1993,26(3-4):109-113
The single specimen technique is effectively used in classical fracture mechanics for evaluating the J-integral from a single test record. It was previously shown using a cracked lap shear specimen that the technique can be applied to composite structures and the energy release rate of composite laminates can be determined from a single test specimen. The objective of this investigation is to determine the ηel form of a double cantilever beam (DCB) specimen, and to compare it with that of a compact tension (CT) specimen. The result showed that while ηel is linearly related to crack length for the CT specimen, it is proportional to the reciprocal of the crack length for the DCB composite specimen. Also, GIc determined from the compliance method was compared with that determined from the ηel approach. The result showed that the ηel form determined from a single beam analysis can be used to determine GIc from a single test record. 相似文献
84.
A 2.5-GHz/900-MHz dual fractional-N/integer-N frequency synthesizer is implemented in 0.35-μm 25-GHz BiCMOS. A ΔΣ fractional-N synthesizer is employed for RF channels to have agile switching, low in-band noise, and fine frequency resolution. Implementing two synthesizers with an on-chip ΔΣ modulator in a small package is challenging since the modulator induces substantial digital noise. In this work, several design aspects regarding noise coupling are considered. The fractional-N synthesizer offers less than 10-Hz frequency resolution having the in-band noise contribution of -88 dBc/Hz for 2.47-GHz output frequency and -98 dBc/Hz for 1.15-GHz output frequency, both measured at 20-kHz offset frequency. The prototype dual synthesizer consumes 18 mW with 2.6-V supply 相似文献
85.
Y. R. Choi E. W. Lusas K. C. Rhee 《Journal of the American Oil Chemists' Society》1982,59(12):564-567
Nondairy coffee whiteners were prepared on a pilot scale using four different glandless cottonseed protein isolates prepared
by different processes. Bulk density, whitening capacity, cream separation and oil retention capacity of the whiteners were
compared to those formulated with sodium caseinate and a commercial whitener. Glandless cottonseed protein isolates, prepared
by conventional and aqueous extraction processes, are poor ingredients for coffee whitener production, showing poor whitening
capacity, separation of proteins through sedimentation and separation of fat as a cream layer in a mixture with aqueous coffee.
Succinylated cottonseed proteins showed many markedly improved characteristics as coffee whiteners. Ca. 50% replacement of
sodium caseinate with succinylated cottonseed protein isolate did not affect the quality of whiteners compared to that of
100% sodium caseinate-based whitener. 相似文献
86.
The processability of single bubble polyamide 11 and polyamide 12 films was investigated. The development of crystalline structure and chain orientation of polyamide 11 and polyamide 12 films in single bubble film blowing was studied by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXS), infrared (IR) spectroscopy, and birefringence. DSC measurements of both films revealed a spontaneous increase in glass transition temperature (Tg) and cold crystallization temperature (Tc) during aging at room conditions, with crystallinity and melting point remaining constant. Single bubble polyamide 11 and polyamide 12 films exhibited triclinic α and monoclinic γ crystals, respectively. The level of biaxial orientation was evaluated by calculating White‐Spruiell biaxial orientation factors with pole figure data. We were not able to produce biaxially oriented double bubble films with either polyamide 11 or polyamide 12. 相似文献
87.
Sook Y. Kim Peter S. W. Park Khee C. Rhee 《Journal of the American Oil Chemists' Society》1992,69(8):755-759
Cheese analogs were prepared from untreated or proteolytically modified soy protein isolates (SPIs), replacing 60% of casein,
to explore their potential to replace higher-priced milk proteins. Quality attributes of cheese analogs were evaluated by
texture profile analysis with the Instron and melting spread. Compared with commercial milk-based cheeses, ranging from hard-type
(Cheddar) to soft-type products (Mozzarella), textural properties of cheese analogs were markedly different; they were harder
and more fracturable with no measurable adhesiveness. The use of enzyme-modified SPI significantly (P < 0.05) lowered both hardness and fracturability of cheese analogs and also brought about adhesiveness, all of which fell
within the range observed for dairy cheeses. Although melting spread of cheese analogs was improved by the use of enzyme-modified
SPI, it was still inferior to those of dairy cheeses and needed further improvement. Treatments of SPI with alcalase and trypsin
were more influential in modifying textural properties of the resulting cheese analogs than those with other proteases studied. 相似文献
88.
Taek Ho Yang Young Jang Jeong Jun Han Joon Shick Rhee 《Journal of the American Oil Chemists' Society》2001,78(3):291-296
For the synthesis of low-calorie structured lipids (LCSL), transesterification between triacetin and stearic acid using immobilized lipase in a solvent-free system was investigated. Stearic acid, a long-chain saturated fatty acid, was incorporated mainly into the sn-1 and/or sn-3 positions of triacetin by lipase-catalyzed reaction. Three types of reactor systems (open, closed, and vacuum) were studied for the production of LCSL. The effects of various reaction variables such as water activity of substrates and lipase, molar ratio of substrates, stirring speed and reaction temperature were investigated. In the vacuum reactor system, a certain amount of water was added periodically to maintain the optimal water content of the reaction system. When a suitable amount of water (0.65 wt% of substrates) was added at every 1 h into the vacuum reactor system, more than 88% LCSL was obtained within 4 h using Chirazyme® L-2. 相似文献
89.
Contact-induced Damage in Ceramic Coatings on Compliant Substrates: Fracture Mechanics and Design 总被引:2,自引:0,他引:2
Young-Woo Rhee Hae-Won Kim Yan Deng Brian R. Lawn 《Journal of the American Ceramic Society》2001,84(5):1066-1072
Simple explicit relations are presented for the onset of competing fracture modes in ceramic coatings on compliant substrates from Hertzian-like contacts. Special attention is given to a deleterious mode of radial cracking that initiates at the lower coating surface beneath the contact, in addition to traditional cone cracking and quasiplasticity in the near-contact area. The critical load relations are expressed in terms of well-documented material parameters (elastic modulus, toughness, hardness, and strength) and geometrical parameters (coating thickness and sphere radius). Data from selected glass, Al2 O3 and ZrO2 coating materials on polycarbonate substrates are used to demonstrate the validity of the relations. The formulation provides a basis for designing ceramic coatings with optimum damage resistance. 相似文献
90.
TS-1, Ti-beta and Ti-MCM-41 molecular sieves have been prepared by direct hydrothermal synthesis method and applied to the epoxidation of n-hexene and cyclohexene with H2O2 under mild conditions. Ti-beta with extremely low Al content was synthesized by using a seed method to suppress the formation of diol produced by Brønsted acid sites present in Ti-beta. It was also found that a large amount of by-products (1-ol and 1-one) formed over hydrophilic Ti-MCM-41. We further modified Ti-MCM-41 by silylation with bis(trimethylsilyl) trifluoroacetamide (BSTFA). Among these catalysts, the Ti-beta with low content of Al enhanced the yield of epoxide and suppressed the formation of diol markedly. The silylated Ti-MCM-41 reduced the formation of by-products and promoted the yields of epoxide significantly. Based on experimental results, a reaction mechanism with two parallel and competitive reactions was proposed. 相似文献