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71.
Evolutionary growth of the use of information technology in business operations now provides a new information-age opportunity for managers, that of providing information for customers (PIC). In the PIC applications, information is a product not a resource and the product is information, not data. Pertinent examples of firms using PIC and steps to be taken by any firm that desires to implement this concept are explained in some detail. This application of computer technology usually can be implemented at minimal costs. PIC provide competitive advantages to the firm by tangibilizing various information services for customers. 相似文献
72.
Shang Hyon Shin 《Journal of Mechanical Science and Technology》2005,19(10):1885-1890
The contour method relies on deformations that occur when a residually stressed component is cut along a plane. The method
is based on the elastic superposition principle. When plasticity is involved in the relaxation process, stress error in the
resulting measurement of residual stress would be caused. During the cutting the specimen is constrained at a location along
the cut so that deformations are restrained as much as possible during cutting. With proper selection of the constraining
location the plasticity effect can also be minimized. Typical patterns of longitudinal welding residual stress state were
taken to assess the plasticity effect along with constraining locations. 相似文献
73.
Development of artificial articular cartilage 总被引:7,自引:0,他引:7
Oka M Ushio K Kumar P Ikeuchi K Hyon SH Nakamura T Fujita H 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2000,214(1):59-68
Attempts have been made to develop an artificial articular cartilage on the basis of a new viewpoint of joint biomechanics in which the lubrication and load-bearing mechanisms of natural and artificial joints are compared. Polyvinyl alcohol hydrogel (PVA-H), 'a rubber-like gel', was investigated as an artificial articular cartilage and the mechanical properties of this gel were improved through a new synthetic process. In this article the biocompatibility and various mechanical properties of the new improved PVA-H is reported from the perspective of its usefulness as an artificial articular cartilage. As regards lubrication, the changes in thickness and fluid pressure of the gap formed between a glass plate and the specimen under loading were measured and it was found that PVA-H had a thicker fluid film under higher pressures than polyethylene (PE) did. The momentary stress transmitted through the specimen revealed that PVA-H had a lower peak stress and a longer duration of sustained stress than PE, suggesting a better damping effect. The wear factor of PVA-H was approximately five times that of PE. Histological studies of the articular cartilage and synovial membranes around PVA-H implanted for 8-52 weeks showed neither inflammation nor degenerative changes. The artificial articular cartilage made from PVA-H could be attached to the underlying bone using a composite osteochondral device made from titanium fibre mesh. In the second phase of this work, the damage to the tibial articular surface after replacement of the femoral surface in dogs was studied. Pairs of implants made of alumina, titanium or PVA-H on titanium fibre mesh were inserted into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. The clinical implications of the possible use of this material in articular resurfacing and joint replacement are discussed. 相似文献
74.
Distortion Compensation of Reconstructed Hologram Image in Digital Holographic Display Based on Viewing Window 下载免费PDF全文
Minsik Park Hyun‐Eui Kim Hyon‐Gon Choo Jinwoong Kim Cheong Hee Park 《ETRI Journal》2017,39(4):480-492
A holographic display based on a viewing window enables the converging of a reconstruction wave into a viewing window by means of an optical system. Accordingly, a user can observe a reconstructed hologram image, even with a small diffraction angle. It is very difficult to manufacture an optical system with no aberrations; thus, it is inevitable that a certain amount of wave aberrations will exist. A viewing‐window‐based holographic display, therefore, always includes distortions in an image reconstructed from a hologram pattern. Compensating the distortions of a reconstructed image is a very important technical issue because it can dramatically improve the performance when reconstructing a digital three‐dimensional content image from a hologram pattern. We therefore propose a method for suppressing image distortion by measuring and compensating the wave aberration calculated from a Zernike polynomial, which can represent arbitrary wave aberrations. Through our experimental configuration using only numerical calculations, our proposed method decreased the reconstructed image distortion by more than 28%. 相似文献
75.
Ionic Liquid Activation of Amorphous Metal‐Oxide Semiconductors for Flexible Transparent Electronic Devices 下载免费PDF全文
Pushpa Raj Pudasaini Joo Hyon Noh Anthony T. Wong Olga S. Ovchinnikova Amanda V. Haglund Sheng Dai Thomas Zac Ward David Mandrus Philip D. Rack 《Advanced functional materials》2016,26(17):2820-2825
Amorphous metal‐oxide semiconductors offer the high carrier mobilities and excellent large‐area uniformity required for high performance, transparent, flexible electronic devices; however, a critical bottleneck to their widespread implementation is the need to activate these materials at high temperatures which are not compatible with flexible polymer substrates. The highly controllable activation of amorphous indium gallium zinc oxide semiconductor channels using ionic liquid gating at room temperature is reported. Activation is controlled by electric field‐induced oxygen migration across the ionic liquid‐semiconductor interface. In addition to activation of unannealed devices, it is shown that threshold voltages of a transistor can be linearly tuned between the enhancement and depletion modes. Finally, the first ever example of transparent flexible thin film metal oxide transistor on a polyamide substrate created using this simple technique is demonstrated. This study demonstrates the potential of field‐induced activation as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications. 相似文献
76.
Dongna Jung-Hyun Joo Hyon Song-Yul Seung-Hyun Howard C. Dong-Joo 《Sensors and actuators. A, Physical》2009,154(1):103-108
A PZT piezoelectric cantilever with a micromachined Si proof mass is designed and fabricated for a low frequency vibration energy harvesting application. The SiO2 layer in the SOI wafer promotes accurate control of the silicon thickness that is used as a supporting layer in the cantilever beam structure. The entire effective volume of the fabricated device is about 0.7690 mm3. When excited at 0.75g (g = 9.81 m/s2) acceleration amplitude at its resonant frequency of 183.8 Hz, the AC output measured across a resistive load of 16 kΩ connecting to the device in parallel has an amplitude of 101 mV. The average power and power density determined by the same measurement conditions are, respectively, 0.32 μW and 416 μW/cm3. 相似文献
77.
Lee J Lee Y Youn JK Na HB Yu T Kim H Lee SM Koo YM Kwak JH Park HG Chang HN Hwang M Park JG Kim J Hyeon T 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(1):143-152
Uniformly sized silica-coated magnetic nanoparticles (magnetite@silica) are synthesized in a simple one-pot process using reverse micelles as nanoreactors. The core diameter of the magnetic nanoparticles is easily controlled by adjusting the w value ([polar solvent]/[surfactant]) in the reverse-micelle solution, and the thickness of the silica shell is easily controlled by varying the amount of tetraethyl orthosilicate added after the synthesis of the magnetite cores. Several grams of monodisperse magnetite@silica nanoparticles can be synthesized without going through any size-selection process. When crosslinked enzyme molecules form clusters on the surfaces of the magnetite@silica nanoparticles, the resulting hybrid composites are magnetically separable, highly active, and stable under harsh shaking conditions for more than 15 days. Conversely, covalently attached enzymes on the surface of the magnetite@silica nanoparticles are deactivated under the same conditions. 相似文献
78.
Chang-Won Lee Hyon Son 《Antennas and Propagation, IEEE Transactions on》1999,47(1):171-178
The analysis of a periodically slotted dielectrically filled parallel-plate waveguide as a leaky-wave antenna for infinite and finite periodic structures for the E-polarization case is discussed. For the analysis of the infinite periodic structure, an integral equation in which Floquet's modes and the strip electric current satisfying the edge condition are used and Bloch wave analysis using the single-slot equivalent circuit parameters are employed. An integro-differential equation with moment-method and transmission-line analysis with equivalent circuit representation are used to analyze the finite N-periodic structure. Results of interest such as complex propagation constant and the radiation pattern for the finite slot number case are observed to be in good agreement with those of the infinite geometry case for the appropriately chosen values of slot numbers, slot width, period, and waveguide height 相似文献
79.
Electroconductive fabrics were prepared to improve the properties of conductive electrode pad material used for electrotherapy when it is subjected to various movements of the human body. Highly stretchable and conductive fabrics were prepared by in situ electrochemical polymerization of polypyrrole (PPy) on nylon/spandex stretchable fabric in aqueous solutions with 0.05M pyrrole and 0.05M anthraquinone‐2‐sulfonic acid, sodium salt monohydrate (AQSA) at room temperature for 2 h. Electroless Cu plating was also applied after chemical polymerization of PPy to improve the conductivity of the fabric pad. Performance of prepared stretchable conductive fabric pad was evaluated in terms of conductivity changes as a function of extension and continuous current application time, and clinical test. As a result, the fabric conductivity was well maintained with extension up to 60% and prolonged treatment time over 30 min. The effect of transcutaneous electrical nerve stimulation (TENS) was observed with prepared TENS pad in this study and conventional TENS pad for medical use. The significant effect of TENS was observed with a pad made of conductive fabric by Cu plating and a conventional TENS pad (P < 0.05, respectively). Even though the efficiency of an experimental pad made of fabric composite with electrochemically polymerized PPy was not as good as conventional TENS pad for medical use in this experiment, it can possibly be used for other applications where relatively low‐strength electrical pulse is required. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 4064–4071, 2004 相似文献
80.