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71.
Sehyun Tak Sunghoon Kim Simon Oh Hwasoo Yeo 《Computer-Aided Civil and Infrastructure Engineering》2016,31(10):777-793
Travel time prediction is one of the most important components in Intelligent Transportation Systems implementation. Various related techniques have been developed, but the efforts for improving the applicability of long‐term prediction in a real‐time manner have been lacking. Existing methods do not fully utilize the advantages of the state‐of‐the‐art cloud system and large amount of data due to computation issues. We propose a new prediction framework for real‐time travel time services in the cloud system. A distinctive feature is that the prediction is done with the entire data of a road section to stably and accurately produce the long‐term (at least 6‐hour prediction horizon) predicted value. Another distinctive feature is that the framework uses a hierarchical pattern matching called Multilevel k‐nearest neighbor (Mk‐NN) method which is compared with the conventional k‐NN method and Nearest Historical average method. The results show that the method can more accurately and robustly predict the long‐term travel time with shorter computation time. 相似文献
72.
Random copolyimides with different proportions of a diamine component were prepared by polymerizing different compositions of diamines with various dianhydrides and imidized thermally to 260°C. The imidization percent of poly(amic acid) was characterized at various temperatures by infrared spectroscopy. The homopolyimide based on bis[4‐(3‐aminophenoxy)phenyl]sulfone and pyromellitic dianhydride was the only one soluble. By changing the compositions of bis[4‐(3‐aminophenoxy)phenyl]sulfone and other diamines with pyromellitic dianhydride in N‐methyl‐2‐pyrrolidone, soluble random copolyimides could be prepared. By random copolymerization, the thermal properties and viscosities of homopolyimide could be controlled. All the soluble polyimides prepared in this work were amorphous because of the lack of stereoregularity. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 272–277, 1999 相似文献
73.
74.
Molecular structure and granule morphology of native and heat‐moisture‐treated pinhão starch 下载免费PDF全文
Vania Z. Pinto Khalid Moomand Nathan L. Vanier Rosana Colussi Franciene A. Villanova Elessandra R. Zavareze Loong‐Tak Lim Alvaro R. G. Dias 《International Journal of Food Science & Technology》2015,50(2):282-289
Pinhão seed is an unconventional source of starch and the pines grow up in native forests of southern Latin America. In this study, pinhão starch was adjusted at 15, 20 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. A decrease in λ max (starch/iodine complex) was observed as a result of increase in temperature and moisture content of HMT. The ratio of crystalline to amorphous phase in pinhão starch was determined via Fourier transform infra red by taking 1045/1022 band ratio. A decrease in crystallinity occurred as a result of HMT. Polarised light microscopy indicated a loss of birefringence of starch granules under 120 °C at 25% moisture content. Granule size distribution was further confirmed via scanning electron microscopy which showed the HMT effects. These results increased the understanding on molecular and structural properties of HMT pinhão starch and broadened its food and nonfood industrial applications. 相似文献
75.
In this paper, we first introduce the use of an interactive hidden Markov model (IHMM) for modeling and analyzing default
data in a sector. Under the IHMM, transitions of the hidden risk states of the sector depend on the observed number of bonds
in the sector that default in the current time period. This incorporates the feedback effect of the number of defaults on
the transitions of the hidden risk states. This feature seems to be more realistic and does not enjoy by the traditional HMMs.
We then develop a “dynamic” version of the binomial expansion technique (BET) modulated by the IHMM for modeling the occurrence
of defaults of bonds issued by firms in the same sector. Under the BET modulated by the IHMM, the number of bonds defaulting
in each time period follows a Markov-modulated binomial distribution with the probability of defaulting of each bond depending
on the states of the IHMM, which represent the hidden risk states of the sector. Efficient method will be presented for estimating
the model parameters in the BET modulated by the IHMM. We shall compare the hidden risk state process extracted from the IHMM-modulated
BET with that extracted from the BET modulated by HMM in order to illustrate the significance of the feedback effect using
real data. We shall also present the estimation results for the BET modulated by the IHMM and compare them with those for
the BET modulated by the HMM. 相似文献
76.
77.
As the number of the silver generation increases, u-health service has evolved into more preventive services accessible in any type of service environment based on service platforms from the previous treatment and management-oriented services for specific diseases. U-health service used to solely provide remote diagnosis and counseling or biometrics monitoring, facing limitations in preventing or managing potential chronic disease cases. In this recognition, the research seeks to propose a P2P-based u-health cluster service model for silver generation in PBR(Personal Bio Record) platform. The proposed u-health service herein utilizes PCs and smart phones to provide health, dietary and exercise information regardless of time and space. Based on the PBR platform, the system effectively connects the EMR system and users’ service systems in order to understand service targets’ lifestyle patterns and offer further customized services. This u-health cluster service model is expected to realize useful services to user in a multi-platform environment and contribute to enhanced health status of senior patients with chronic disease. 相似文献
78.
van der Tak FF 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2006,364(1848):3101-3106
The H3+ and H2D+ ions are important probes of the physical and chemical conditions in regions of the interstellar medium where new stars are forming. This paper reviews how observations of these species and of heavier ions such as HCO+ and H3O+ can be used to derive chemical and kinematic properties of nearby pre-stellar cores and the cosmic ray ionization rate towards more distant regions of high-mass star formation. Future prospects in the field are outlined at the end. 相似文献
79.
Optical image encryption based on interference has attracted a lot of attention recently. The technique employs two pure phase masks derived from the complex field of the image in the Fresnel diffraction domain. The image decryption procedure can be carried out by inverse Fresnel transformation of the summation of two pure phase masks. However, the silhouette of the original image, which is recovered by either of the two phase-only masks, impedes the application of this technique. In this paper, a very simple method for binary image encryption based on interference of two phase-only masks is proposed without any silhouette problem. The binary image in combination with a random phase mask is separated into two phase-only masks directly, and the decryption by summation of the two masks can be performed digitally or optically. In this paper, the encryption and decryption processes are analyzed, after which both the optical simulation and the experimental results based on single-beam holography are given to demonstrate the feasibility of the encryption method. As information nowadays is mainly digitized into binary codes, the proposed encryption method may find applications in the information processing field. 相似文献
80.
Hong Tak KimSang Ho Sohn 《Vacuum》2012,86(12):2148-2151
Hydrogenated amorphous carbon (a-C:H) films were deposited onto glass substrates using low frequency (60 Hz) plasma-enhanced chemical vapor deposition and the effects of the applied power on a-C:H films deposition were investigated. During deposition, the electron temperature and the density of CH4-H2 plasma were 2.4-3.1 eV and about 108 cm−3, respectively. The main optical emission peak of the carbon species observed in the CH4-H2 plasma is shown to be excited carbon CH* at 431 nm. The sp3/sp2 ratio, band gap, hydrogen content, and refractive index of a-C:H films gradually increased up to a power of 25 W and then saturated at higher power. This tendency is similar to the variation of plasma parameters with varying applied power, thereby indicating that a strong relationship exists between the properties of the films and the plasma discharge. 相似文献