This study proposes an analytical approach to the creation of multitouch control-gesture vocabularies applicable to mobile devices. The approach consists of four steps: (a) identifying target commands, (b) extracting gesture features of the target commands, (c) analyzing usage patterns based on elements that consist of multitouch gestures, and (d) creating gesture vocabularies based on the gesture features and elements. Usefulness and practicality of the proposed approach were validated in a case study. The case study created 11 mobile web browsing gestures to improve short-cut interactions. Six volunteers created gestures based on systematic procedures and practical methods. A total of 314 gestures were created in the case study, and the results were compared with those of a previous study that used an empirical approach to design control gestures. The proposed approach helped designers to create appropriate gestures for various commands on mobile devices. It was very practicable for all designers, including even novice users. 相似文献
In a previous study, CETP inhibitory peptide (3 kDa) was isolated from hog plasma. The peptide, synthesized chemically according
to the amino acid sequence of the 3-kDa peptide (designated P28), showed CETP inhibitory activity both in vitro and in vivo [Cho et al. (1998) Biochim. Biophys. Acta 1391, 133–144]. We report herein further unique features of P28 when it was associated with the cholesteryl ester (CE)-donor and-acceptor lipoproteins. Lipoprotein substrates with P28 present in both HDL (as a CE-donor) and LDL (as a CE-acceptor) served as poor substrates, with CE-transfer activity decreased
up to 60% compared to normal substrates without P28. P28 was found to be located in HDL fractions of hog plasma and showed the same electromobility as that visualized by PAGE on
7% polyacrylamide gel under nondenaturing conditions. Addition of apolipoprotein A-1 (apoA-1) or apoB antibody to a normal
CE-transfer mixture did not alter CE-transfer activity. However, addition of apoA-1 or −B antibody to a CETP-inhibition mixture
decreased the inhibitory activity of P28 by ca. 20%. Western blot analysis revealed that P28 was associated only with human and hog HDL among several lipoproteins purified from human, hog, and rabbit. CFTP-inhibition
assays with various lipoprotein substrates revealed that P28 exhibited substrate-specific inhibitory activity. The inhibitory activity of P28 was highly dependent on the type of lipoprotein substrate (whether CE-donor or-acceptor); P28 inhibited CE transfer from HDL to LDL, but it did not inhibit CE transfer from HDL to HDL. 相似文献
A prototype wind-powered reverse osmosis desalination system was constructed and tested on Coconut Island off the northern coast of Oahu, Hawaii, for brackish water desalination. The system has four major subsystems: a multi-vaned windmill/pump, a flow/pressure stabilizer, a reverse osmosis module, and a control mechanism. The feedback control mechanism, developed by this study, allowed this prototype system to be operated satisfactorily under mild ambient wind of 5 m/s or less. No auxiliary power source was needed. The system operational data showed that at an average wind speed of 5 m/s, brackish feedwater at a total dissolved solids concentration of 3000 mg/1 and at a flow rate of 13 1/min could be processed by this system. The average rejection rate of this prototype system was 97% and the average recovery ratio was 20%. The energy efficiency of the system was measured at 3 5%, which is comparable to the typical energy efficiency of well-operated multi-vaned windmills. Generally, the system's energy efficiency decreases as wind speed increases. 相似文献
Dissipative structures of autocatalytic reactions with initially uniform concentrations are studied in tubular flow reactors. A unique steady state exists in a continuous stirred tank reactor. Linear stability analysis predicts either a stable node, a focus or an unstable saddle-focus. Sustained oscillations around the unstable focus can occur for high values of Damköhler number. In distributed parameter systems, travelling, standing or complex oscillatory waves are detected. For low values of Damköhler number, travelling waves with pseudo-constant patterns are observed. With intermediate values of Damköhler number, single or multiple standing waves are obtained. The temporal behavior indicates also the appearance of retriggering or echo waves. For high values of Damköhler number, both single peak and complex multipeak oscillations are found. In the cell model, both regular oscillations near the inlet and chaotic behavior downstream are observed. In the dispersion model, higher Peclet numbers eliminate the oscillations. The spatial profile shows a train of pulsating waves for the discret model and a single pulsating or solitary wave for the continuous model. 相似文献
Fluidized bed combustion of high ash anthracite (HAA) was experimentally studied. The combustor consists of 0.25 m ID bed,
and auxiliary equipments for coal feeding, ash removal, lemperature control, etc. Experimental results elucidate main cause
of fuel loss to be elutriation of fines (i.e., flyash) containing unburned carbon. However, detailed balances of particle
size distribution show majority of carbon in flyash comes from fines contained in the feed instead of attrition of coarse
particles. The latter is the main source of flyash for conventional coal. The difference is due to much smaller attrition
rate of HAA; feed HAA particles do not shrink much in size by combustion and attrition. 相似文献
Single-crystal silicon wafers ((1 1 1) and (1 0 0)p-type) were abraded at room temperature 300 °C, and 600 °C by a polycrystalline partially stabilized zirconia ball in a ball-on reciprocating flat geometry. The sliding direction was 1 1 0. The friction coefficient was recorded as a function of reciprocating strokes and the deformation mode of the silicon. The friction coefficient at room temperature decreased with the number of strokes, and this variation was less affected by the number of strokes at the higher temperatures. The wear track width and depth were measured at the three temperatures. Wear increases as the temperature is raised to 300 and 600 °C. Optical and scanning electron microscopy of the subsurface damage reveals that cracks are generated at RT and 300 °C and dislocations are produced at 600 °C. The change in deformation mode with temperature from brittle fracture to plastic deformation accounts for the differences in wear. 相似文献
In an Internet-of-Things (IoT) environment, congestion and scarcity problems may occur because many mobile stations (STAs) access wireless networks simultaneously. The IEEE 802.11ax/802.11be standards for large-scale wireless communications have defined a trigger frame (TF) to control multiple STAs. During resource allocation, the downlink (DL) transmission is divided in a control period from the access point (AP) to multiple STAs. The resource allocation (RA) is then assigned to an uplink (UL) transmission by a TF and a DL period from the AP to STAs. However, because the DL transmission should be considered separately in terms of the control and DL periods, it is necessary to analyze the DL transmission. We propose a scheduled MU transmission (SMT) algorithm for enhanced UL and DL MU MIMO transmissions. In this study, we analyze and systematically model medium access control (MAC) performance when the DL transmission is divided in the control and data periods when the UL coexists with the DL data transmission. To achieve this, we mathematically analyze the time-efficient throughput, estimate the transmission and collision probabilities for wireless local area network (WLAN) STAs, and generalize the transmission interval. In addition, we propose an access category (AC) for the TF that is defined in the DL transmission. All data transmissions are defined as the ACs for basic channel access, but the AC is not defined for the TF. Therefore, we clarify the transmission by defining the AC of the TF to control the UL transmissions of various STAs. Evaluation results demonstrate that the SMT algorithm can improve the MAC throughput by up to 70% – 87% compared to UL and DL MU MIMO transmissions.
This paper presents a power-smoothing scheme of a variable-speed wind turbine generator (VSWTG) that employs separate control gains for the over-frequency section (OFS) and under-frequency section (UFS). In the proposed scheme, an additional proportional control loop based on the system frequency deviation operating in conjunction with maximum power point tracking operation is used. In the OFS, to improve the energy-storing capability, the scheme suggests the gain of the frequency deviation control loop, which is set to be monotonously decreasing with the rotor speed while being significantly larger than that in the UFS. In the UFS, to improve the energy-releasing capability while preventing over-deceleration, the gain of the frequency deviation control loop is set to be a linear function of the rotor speed. The simulation results under continuously varying wind speeds with different wind patterns and wind speeds clearly demonstrate that the proposed scheme significantly mitigates the output power fluctuations of a VSWTG. The proposed scheme keeps the frequency within a narrow range, thereby reducing the required primary frequency control reserve for regulating the frequency under normal operations.
Regardless of the type of performed restoration, in most cases, a screw connection is employed between the abutment and implant.
For this reason, implant screw loosening has remained a problem in restorative practices. The purpose of this study was to
compare the surface of coated/plated screws with titanium and gold alloy screws and to evaluate the physical properties of
coated/plated material after scratch tests via FE-SEM (field emission scanning electron microscopy) investigation. GoldTite,
titanium screws provided by 3i (Implant Innovation, USA) and TorqTite, titanium screws by Steri-Oss (Nobel Biocare, USA) and
gold screws and titanium screws by AVANA (Osstem Implant, Korea) were selected for this study. The surface, crest, and root
of the abutment screws were observed by FE-SEM. A micro-diamond needle was also prepared for the scratch test. Each abutment
screw was fixed, and a scratch on the surface of the head region was made at constant load and thereafter the fine trace was
observed with FE-SEM. The surface of GoldTite was smoother than that of other screws and it also had abundant ductility and
malleability compared with titanium and gold screws. The scratch tests also revealed that teflon particles were exfoliated
easily in the screw coated with teflon. The titanium screw had rough surface and low ductility. The clinical use of gold-plated
screws is recommended as a means of preventing screw loosening. 相似文献
Identification of chatter free cutting conditions, the chatter stability lobes, requires a measurement of the frequency response function (FRF) of each tool mounted on the spindle. This paper presents a method of assembling known dynamics of the spindle–tool holder with an analytically modeled end mill using the receptance coupling technique. The classical receptance technique is enhanced by proposing a method of identifying the end mill–spindle/tool holder joint dynamics, which include both translational and rotational degrees of freedom. The method requires measurement of FRFs with impact tests applied on the spindle–tool holder assembly and blank calibration cylinders attached to the spindle. The spindle and tool holder characteristics are completely identified from the two experiments, and used for the mathematical prediction of FRF for end mills with arbitrary dimensions. The proposed method is experimentally proven and verified in cutting tests. 相似文献