Search

Urban building energy modeling (UBEM) is arousing interest in building energy modeling, which requires a large building dataset as an input. Building use is a critical parameter to infer archetype buildings for UBEM. This paper presented a case study to determine building use for city-scale buildings by integrating the Geographic Information System (GIS) based point-of-interest (POI) and community boundary datasets. A total of 68,966 building footprints, 281,767 POI data, and 3367 community boundaries were collected for Changsha, China. The primary building use was determined when a building was inside a community boundary (i.e., hospital or residential boundary) or the building contained POI data with main attributes (i.e., hotel or office building). Clustering analysis was used to divide buildings into sub-types for better energy performance evaluation. The method successfully identified building uses for 47,428 buildings among 68,966 building footprints, including 34,401 residential buildings, 1039 office buildings, 141 shopping malls, and 932 hotels. A validation process was carried out for 7895 buildings in the downtown area, which showed an overall accuracy rate of 86%. A UBEM case study for 243 office buildings in the downtown area was developed with the information identified from the POI and community boundary datasets. The proposed building use determination method can be easily applied to other cities. We will integrate the historical aerial imagery to determine the year of construction for a large scale of buildings in the future.

Purposes The aim of this study was to introduce a method for repairing donor site defects after harvesting forearm free flaps with dual triangular flaps combined with in situ small full-thickness skin flaps. Methods Free forearm skin flaps were applied to repair defects after tumor resection in 25 patients with oral squamous cell carcinoma. Although forearm free flaps were prepared, dual triangular flaps and adjacent full-thickness skin flaps were designed and fabricated to repair donor site defects in situ. Results Twenty-five cases of forearm donor site defects were successfully repaired with dual triangular flaps combined with in situ small full-thickness skin grafts. All adjacent full-thickness skin grafts used to close the donor site defect of the forearm survived, and the wound healed well without delayed wound rupture or serious complications at the donor site. The movement of the elbow and wrist joint on the side of the flap was normal, the blood supply in the palm was normal, and the skin color at the donor site of the forearm skin flap was similar to that of the surrounding tissue. There was no dent deformity or contracture deformity. Moreover, there was no significant difference in swelling and wrist movement between the adjacent forearm skin grafting group and the abdominal skin grafting group, but the former technique reduced the risk of scar infection and tendon exposure and greatly improved the esthetics of the surgical site on the forearm. Conclusions Modified donor dual triangular flaps combined with adjacent full-thickness skin grafts can reduce the recovery time during and after surgery and avoid trauma at a third surgical site. This method is worthy of practical application in the preparation of forearm skin flaps for oral and maxillofacial surgery.

This paper takes the closed eight-bar mechanism in large tonnage punching press as the study object. The geometric dimensions of the mechanism were optimized and designed on the basis of three design requirements of slider total stroke, maximum stretching depth and maximum stretching speed in effective tension process. The parametric model of the mechanism was built in the RecurDyn environment, and the displacement curve and velocity curve were obtained through the kinematic simulation. Based on the displacement curve, the slider total stroke was calculated. Based on the velocity curve and the maximum stretching speed requirement in the process of effective tension, the available maximum stretching depth was calculated and the dimension parameters of the mechanism were gained at last. The optimization results show that the available maximum stretching depth increased by 39% while the total length of eight bars remains unchanged.

Urban building energy modeling (UBEM) is attracting increasing attention in the energy modeling filed. Unlike modeling a single building using detailed building systems information, UBEM generally uses limited high-level building stock data to infer default assumptions about building characteristics and operations. This practice inherently brings uncertainty to UBEM. This study introduced a novel method of automatic and rapid calibration of UBEM based on the annual electricity and natural gas energy use data by learning the correlations between crucial model input parameters and the building energy use from the reference building models. A case study was presented to calibrate 72 large office buildings built before 1978 in San Francisco. Seventeen model parameters were selected and Monte Carlo sampling was used to create 1000 samples that reasonably represent the parameter space. Then 1000 simulations were performed for the reference building model to create an energy performance database. The results showed that by learning from the energy performance database, it took less than four simulation runs on average to calibrate a building model. After the calibration, the distributions of each parameter were obtained to replace their single predefined default values. For example, the default lighting power density of 21.39 W/m2 was calibrated to be 7.50 W/m2 on average. The case study successfully demonstrated the effectiveness of the novel calibration method for UBEM in the mild climate. The method will be further tested in future for other climate zones and other building types.

The PCE has a great relationship with the work function of conductors in organic and printed electronics devices. And organic photovoltaics require an electrode with a work function (WF) that is low enough to either facilitate the transport of electrons in and out of various optoelectronic devices or collect electrons from the lowest unoccupied molecular orbital (LUMO) of a given organic semiconductor. In inverted organic photovoltaics, the ITO is normally used as cathode to collect electrons .By using PDDA deposition, the surface work function of ITO can be decreased by 0.3 eV, which is able to improve the electrons transport and the PCE in OPV, as it has been proved that the surface electronic potential of ITO is very sensitive to the presence of self-assembled molecular layers.

To sail and work safely in different working conditions, the ballast system of a certain crane vessel is researched and designed because it’s strict with hull stability. According to the characteristic of the vessel arrangement, the concept of ring pipe type is adopted in the ballast system. The dual and single ring types of ballast system are designed, analyzed and comprised with each other respectively. Simultaneously, the normal materials of ballast system are analyzed, and the suitable material is selected.

Development of digital signal processing and embedded technologies today, to the development of radar technology has brought new opportunities. Relative to the simulation of radar, digital radar has good performance, features, ease of operation, and other benefits. Design based on embedded processor and digital signal processor (DSP) dual processor shipboard navigation radar system, and focuses on digital shipborne navigational radar system architecture, hardware design and software algorithms for digital signal processing module, gives the overall scheme for DSP systems.

Condition assessment for power transformer requires not only integrating the known artificial intelligence (AI) technology, but also exploiting the interrelation of the measured data. According to the association rule of information data and the variable weight synthesizing theory of factor spaces, an assessment method of transformer condition was proposed in this paper. Via analyzing the interrelation of the independent status parameters (ISP) and transformer fault types, the set of synthetic status parameters (SSP) can be built up. For avoiding interference from subjective experience, association rule theory was used to calculate the constant weight coefficients (CWC) of the ISPs. Since the true transformer condition may not always be accurately reflected under the condition of CWCs of a few SSPs, the method of variable weight synthesizing was used for computing the variable weight coefficients (VWC) of the SSPs. Then, combining with the existing maintenance procedures, a preferable condition assessing system of power transformer was proposed. Operational example proved the condition assessing system may reflect the real operation condition of power transformer.

The paper presents a video residual reconstruction framework wherein the difference between the two adjacent decoded key frames acts as the side information to aid the CS recovery of the residual between the target frame and its prediction. To accelerate the residual reconstruction, a fast yet effective approach is developed to estimate the sparsity level of the residual, in which hard thresholding is employed to identify all significant coefficients in some sparse transform. The experimental results show that video residual reconstruction with the proposed sparsity estimation yields superior reconstruction abilities in both visual quality and computational efficiency across a broad range of sub-sampling rates.

In the background of complex supply chain management, this paper builds a multi-period inventory model in the case of uncertain demand. Downstream node enterprises to adopt (s, Q) production strategy to control production and inventory. Midstream node enterprises have also established the mutually corresponding dynamic inventory turnover policy. All node enterprises are willing to join force with others. So the whole supply chain can achieve the lowest inventory cost. And unlike the case of non-cooperation, just a single node enterprise pursue its inventory cost to reach the lowest value. We make good use of Matlab and Lingo to carry out simulation and analysis. We can draw the best production period and best preparation period of downstream node enterprises, as well as the optimal value of inventory cost of the entire supply chain.

Catalyst-free InP/InGaAs core-shell nanowires were grown on Si(100) substrates by metal-organic chemical vapor deposition.These nanowires have quite different properties to Au-catalyst core-shell nanowires.By using scanning electron microscope,we found that the catalyst at the top of the InP nanowires had been transformed into crystal after the InGaAs core grown on them.Meanwhile,the diameter of the nanowires has greatly increased with their length changed quite little.The X-ray diffraction patterns indicate that the transformation of the catalyst is attributed to the temperature rise under PH3 protection before InGaAs core growth.By transmission electron microscope and energy dispersive X-ray spectroscopy,it is proved that the transformation of catalyst is prior to the InGaAs core growth and is cover by InGaAs which is same to the nanowires sidewall.

It is a challenging task to improve the real-time property and objectivity of the effect assessment for the distance education. This paper presents a QoE (Quality of Experience) assessment system based on the attention of online user. The system captures the video frames from two cameras periodically and synchronously, using the adaptive image binarization based on the linear average threshold for the pretreatment, then processing with edge detection and filtering in the cross-directions at the same time. System gets the position of computer screen and user eyeball. Analyzing the detection results comprehensively obtains the attention of online user by some judging conditions, and finally acquires the quality of user experience. Experimental results demonstrate the feasibility and efficiency.

In order to receive and process the open loop signal from fiber optic gyroscopes speedily, stably and expediently, and to realize the amity interface between human and machine, a digital system that can convert GPIB (general purpose interface bus) parallel bus into Universal Serial Bus is developed. All the interface functions of GPIB and the hardware system are realized through FPGA. With a digital sampling and processing system designed with VC++ in Windows platform, the real-time controlling procedure, high-speed receiving and sending data can be carried out, and the results can be displayed too. So the design of the system is flexible, the reliability and the stability are improved, error rate is no more than 10−11, the highest bit rate is 8 MB/s and the open loop detection system for optic fiber gyros achieves standardization and complete digitalization simultaneously.

The IPv4 protocol suite is vulnerable to a variety of attacks. IPv6 security is in many ways the same as IPv4 security, the basic mechaisms for transporting packets across the network stay mostly unchanged, and the upper-layer protocols that transport the actual application data are mostly unaffected. This paper illustrates sniffing threat against IPv4 and then compares how the threat might influence an IPv6 networks. This is prefaced by a brief overview of current practices around the design of an IPv4 Internet edge network and then followed by a review of how that IPv4 edge network needs to evolve in order to secure the addition of IPv6. As IPv6 security is a large and complex subject, and also, IPv6 network is still at the very beginning stage and has not been fully examined in fact, this paper focus on the security requirements of medium edge networks.

Using pulse echo overlap measurement, the elastic behavior of amorphous carbon has been studied at ambient and low temperatures. The smaller ratio BIG of the bulk modulus to shear modulus and smaller Poisson's ratio sigma at room temperature indicate that there is an intrinsic stiffening of transverse acoustic phonons in the amorphous carbon. The acoustic velocity and attenuation for longitudinal modes have been measured between 2.1 and 300 K at three frequencies of 7, 21 and 35 MHz, respectively. Their frequency and temperature dependence are observed. The elastic constant C-11 increases with decreasing temperature and show enhanced stiffening at low temperatures. In the 130-220 K region, the abnormal change and effect of longitudinal velocity and attenuation with temperature and frequency, and a phase transition associated with structure relaxations are discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.

A three-level Λ-type atomic system is pumped by an incoherent radiation field. The system lases without population inversion in the steady state. We analyze the inversionless gain and origin of the gain.

By subspace identification technique, this article investigates the problem of control variance performance monitoring for multivariable systems. Based on LQG benchmark, an improved strategy is developed to overcome the deficiency of the conventional LQG benchmark based methods in practical applications. The multivariable system is first decomposed into multiple multi-input single-output (MISO) subsystems. Then the LQG benchmark is respectively obtained for each subsystem and the corresponding variance performance assessment indicator is yielded. The performance monitoring result of the overall system can finally be derived by weighting to each subsystem's assessing indicator. Simulation example illustrated the validity of the proposed method.

In cognitive radio ad hoc networks (CRAHNs), because mobile devices are mainly powered by battery, efficient consumption of energy is a key problem to be improved. In this paper we study how to find an energy efficient route for a session in CRAHNs. We propose a relative energy metric for routing in CRAHNs, and develop two relay users selection methods for CRAHNs, one of which is proactive and the other is reactive. The new routing scheme could select proper relay nodes, channels, and transmitter power for a session, aims to supply enough communication rate, to decrease the average total power consumption of each session, and to prolong the life of the total network at the same time. In addition, we compare the performance of a proactive route scheme with that of reactive method. Numerical results show that the effectiveness of our proposed routing scheme is with good generalization ability, and the reactive node selection method may better satisfy CRNs.

in recent years, with the development of the chemical industry, marine liquid chemicals a steady growth. Research guidelines for the safe operation of dangerous chemicals in bulk liquid, and to ensure the smooth operation of bulk liquid chemicals Terminal, meet the needs of production and domestic and foreign trade, creating huge economic and social benefits, while safeguarding the operational safety of bulk liquid chemicals, maintenance of port operations, protection of shipping, handling, storage, safety of lives and property as well as the entire city is of great significance.

In cognitive radio networks, power control is considered as an important issue to improve the performance of dynamic spectrum sharing. In this paper, in order to maximize the efficiency of the system, the secondary users and primary user behaviors will be considered. Hence, we propose improved utility functions of primary-secondary user based on a power control game model in this study which rewards primary user for sharing its idle spectrum and lets secondary users achieve efficient transmissions. And then, a detailed analysis of the existence and uniqueness of Nash Equilibrium is discussed for the utility functions. Finally, the simulation results show that this power control game method can improve the performance of the scheme in cognitive radio networks significantly.

The security of stream cipher, which was defined as one of the important cipher means, and depended on the performance of existing pseudo random series. Chaos algorithm was sensitive to the initial condition, arbitrariness and relativity. They could form fine pseudo- random series. Consequently, these systems were fit for the stream cipher. Firstly, the chaos encryption algorithm was studied depended on the Logistic function. And then a certain encryption/decryption algorithm was established. The encryption/decryption algorithm was obtained under the environment of VFP. This method could confirm the safety of the database operation system.

This paper describes a novel approach for the photon shot noise reduction in an image sensor inspired from an M-transform method. In our proposed method, the photon shot noise is converted into small amplitude signals. Then, the signals are treated to remove the small amplitude noise by an e filter. The Sobel method is applied to the edge detection. The edge of the object is protected by not treating the e filter into the detect edge. After removal of the noise, the data of M-transform are restored to the image by a reverse M-transform. The proposed method is compared with the smoothing filter, the median filter and the Wiener filter. In cases where the number of the maximum incidence photons was 256 pieces (illumination is about 4 l×), the proposal technique indicated the PSNR (Peak-Signal to Noise Ratio) value better than the Wiener filter. Moreover, also with the low illumination less than 4 l×, the edge is maintained and the proposal technique is judged to be excellent in comprehensive evaluation.

On the Internet, the distributed denial-of-service (DDoS) attack is the most frequently used and most deleterious attack which aims at a single target and causes denial of service for users of the targeted system. Today, network security has become the key for the popularization of all kinds of network applications. In this paper, a model against DDoS attack based on detecting the network traffic character is proposed and the method of detecting DDoS attack by computing the self-similarity parameter of network traffic is studied emphatically. The R/S algorithm is adopted to calculate the on-line Hurst parameter through data reusing, and then the implement is given. The experiment results show that this method can detect the DDoS attack accurately and in time.

Position-sensitive thin-gap gas detectors have been developed in the laboratory, based on the ATLAS Thin Gap Chamber. The signal collection structure has been redesigned while retaining other configurations to keep the good time performance of the detector. The position resolution was measured using cosmic muons for two versions of the detector and found to be 409 μm and 233 μm respectively. This paper presents the structure of these two detector prototypes, with the position resolution measurement method and results.

A new method to decompose digital remotely sensed images is discussed in this paper. The information in the original remotely sensed data can be decomposed, pixel-by-pixel, into three components of natural light - solar direct illuminance (SDI), sky-scattering illuminance (SSI) and atmospheric path radiance (APR). Because the remotely sensed information is the result of the interaction between each component and ground features, the resultant component images of this method are more powerful than the original remotely sensed data in the quantitative inversion research of ground radiation energy, atmospheric environment condition, and remote sensing image pattern recognition.

CO2 sequestration in deep coal seams with enhanced coalbed methane recovery (CO2-ECBM) is emerging as a promising option to stabilise CO2 concentration in the atmosphere. Volumetric method for measuring methane and CO2 adsorption on coal can generate the critical information of the coalbed methane recovery and CO2 storage amount of the target coal seams. In this work, the potential sources of error involved in volumetric method including sample mass, volume, temperature, pressure and compressibility factor and their impact on the measured methane and CO2 adsorption amount have been studied using the law of error propagation. Feasible measures to improve the measured precision based on ‘fixed volume’ method have also been put forward.

On the silicon-on-insulator platform, an ultra compact temperature-insensitive modulator based on a cascaded microring assistant Mach—Zehnder interferometer is proposed and demonstrated with numerical simulation. According to the calculated results, the tolerated variation of ambient temperature can be as high as 134 °C while the footprint of such a silicon modulator is only 340 μm2.