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Flow time is a key material property for underfill materials in flip-chip applications. In this paper, we will discuss how to use flow time testing for underfill flow evaluation and material screening. The flow time of several underfills was measured at elevated temperatures using test pieces made from glass microscope slides. The material properties impacting underfill flow, such as viscosity, contact angle, and surface tension, were also experimentally measured and used to calculate estimated flow times using the Washburn equation. Empirical and calculated flow times were compared. The effects of channel width and flow distance on flow time were also studied. Additionally, the effect of a tilted stage on flow time, epoxy tongue, and void formation was evaluated.

A brittle solder joint at the interface between a solder ball and a substrate metal pad could result in an open joint failure after the solder ball is attached to a motherboard. Existing metrologies, such as ball shear, do not always detect the weak solder joint strength. A peel test for solder joint strength evaluation of substrate was developed. Several problems were observed during the initial stages of the development for this metrology. These included solder bridging and inconsistency of the test results. Solder bridging was reduced by changing the stencil design to have stencil openings that match the solder ball layout and using a jig to align the coupon and substrate while assembling the peel test samples. The paste printing and peeling methods were modified and the coupon quality was carefully monitored to make the sample preparation and testing more consistent. The impact of the physical aging and reflow on the solder joint strength was investigated. It showed that the peel strength did not decrease with physical aging, but did decrease with an increased number of reflows. The peel test results correlated with the performance of the substrates. The substrate with low peel strength had weak solder joints and failed under use conditions. The substrates with high peel strength demonstrated stronger solder joints and performed well under use conditions. The metrology provides a gross check about the presence of brittle solder joints on flip chip ball grid array substrates and is successfully used in monitoring the solder joint strength.

In flip-chip packaging, an underfill is dispensed on one or two adjacent sides of the die. The underfill is driven by a capillary flow to fill the gap between the die and substrate. The application of an underfill reduces the stress to solder bumps and enhances the reliability of the solder joints. Underfill materials consist of epoxy or cyanate ester resins, catalyst, crosslinker, wetting agent, pigment, and fillers. Underfill materials are highly filled with the filler loading ranging from 40% to 70%. In terms of underfill material processing, fast flow and curing are desired for high throughput. The viscosity, surface tension, and contact angle are key material properties affecting the gap filling process. In order to achieve fast filling, it is required that an underfill material has low viscosity and low contact angle at dispensing temperatures. Due to curing of an underfill material at dispensing temperature, the viscosity increases with time, which complicates the underfill flow process. The rheological behavior of several underfill materials was experimentally studied. All the underfill materials showed strong temperature dependence in viscosity before the curing. The time dependent viscosity and curing of underfill materials were examined by a dynamic time sweep test. The effects of viscosity and curing behavior of underfill materials on underfill material processing were investigated. The material with a longer gel time had more stable viscosity at room temperature, and therefore longer pot life. Experimental methods were developed to measure the surface tension and the contact angle of underfills at temperatures over 100 °C. Results showed that the contact angle for underfill on a substrate was time dependent. The interaction between underfill and substrate affects not only gap filling, but also filleting. The effect of surface energies of flip-chip substrates on wetting angles was also studied. Experiment results showed that for the same underfill, the higher the surface energy of substrate, the better the filleting.

The old surface and the fresh surface of the rock samples have been subjected to field spectrum test what should be compared indoor control spectrum test, and the mineral element test of the sample and the observation of the sample under thin film have been carried out. The spectral reflectance of old surface and fresh surface shows that the old effect has little effect on the spectral characteristics of rock minerals which affects the size of the reflectance. The difference are between the mineral elements and the spectral characteristics of the samples. The spectral characteristics and spectral indices of different samples have ex-tracted and the data have extracted for hyper-spectral data extraction of alteration information.

Of all known cultured stem cell types, pluripotent stem cells (PSCs) sit atop the landscape of developmental potency and are characterized by their ability to generate all cell types of an adult organism. However, PSCs show limited contribution to the extraembryonic placental tissues in vivo. Here, we show that a chemical cocktail enables the derivation of stem cells with unique functional and molecular features from mice and humans, designated as extended pluripotent stem (EPS) cells, which are capable of chimerizing both embryonic and extraembryonic tissues. Notably, a single mouse EPS cell shows widespread chimeric contribution to both embryonic and extraembryonic lineages in vivo and permits generating single-EPS-cell-derived mice by tetraploid complementation. Furthermore, human EPS cells exhibit interspecies chimeric competency in mouse conceptuses. Our findings constitute a first step toward capturing pluripotent stem cells with extraembryonic developmental potentials in culture and open new avenues for basic and translational research. VIDEO ABSTRACT.

Mineral resources are important material basis for the survival and development of human society. The development of hyperspectral remote sensing technology, which has made direct identification of minerals or mineral aggregates become possible, paves a new way for the application of remote sensing geology. The West Junggar region is located Xinjiang west verge of Junggar, with ore-forming geological conditions be richly endowed by nature and huge prospecting potentiality. The area has very good outcrop exposure with almost no vegetation cover, which is a natural test new method of remote sensing geological exploration. The characteristic of rock and mineral spectrum is not only the physical base of geological remote sensing technical application but also the base of the quantificational analysis of geological remote sensing, and the study of reflectance spectrum is the main content in the basic research of remote sensing. In this study, we collected the outdoor and indoor reflectance spectrum of rocks and minerals by using a spectroradiometer (ASD FieldSpec FR, ASD, USA), which band extent varied from 350 to 2,500 nm. Basin on a great deal of spectral data for different kinds of rocks and minerals, we have analyzed the spectrum characteristics and change of seven typical mineral rocks. According to the actual conditions, we analyzed the data noise characteristic of the spectrum and got rid of the noise. Meanwhile, continuum removed technology was used to remove the environmental background influence. Finally, in order to take full advantage of multi-spectrum data, ground information is absolutely necessary, and it is important to build a representative spectral library. We build the spectral library of rocks and minerals in Hatu, which can be used for features investigation, mineral classification, mineral mapping and geological prospecting in Hatu Western Junggar region by remote sensing. The result of this research will be significant to the research of accelerating Western Junggar mineral exploration.

The aim of the present study was to determine the antitumor effects of hyperthermic CO2 (HT-CO2)-treated dendritic cell (DC)-derived exosomes (Dex) on human gastric cancer AGS cells. Mouse-derived DCs were incubated in HT-CO2 at 43°C for 4 h. The exosomes in the cell culture supernatant were then isolated. Cell proliferation was analyzed using the cell counting kit-8 (CCK-8) assay. Cell apoptosis was observed using flow cytometry, Hoechst 33258 staining and the analysis of caspase-3 activity. In addition, the proliferation of tumor cells was evaluated in xenotransplant nude mice. HT-CO2 markedly inhibited cell proliferation, as assessed by the CCK-8 assay, and also induced apoptosis in a time-dependent manner, as demonstrated by Annexin V/propidium iodide flow cytometry, caspase-3 activity and morphological analysis using Hoechst fluorescent dye. It was also revealed that HT-CO2-treated Dex decreased the expression of heat shock protein 70 and inhibited tumor growth in nude mice. In conclusion, HT-CO2 exerted an efficacious immune-enhancing effect on DCs. These findings may provide a novel strategy for the elimination of free cancer cells during laparoscopic resection. However, the potential cellular mechanisms underlying this process require further investigation.

Distributed Denial of Service (DDoS) attacks have caused continuous critical threats to the Internet services. DDoS attacks are generally conducted at the network layer. Many DDoS attack detection methods are focused on the IP and TCP layers. However, they are not suitable for detecting the application layer DDoS attacks. In this paper, we propose a scheme based on web user browsing behaviors to detect the application layer DDoS attacks (app-DDoS). A clustering method is applied to extract the access features of the web objects. Based on the access features, an extended hidden semi-Markov model is proposed to describe the browsing behaviors of web user. The deviation from the entropy of the training data set fitting to the hidden semi-Markov model can be considered as the abnormality of the observed data set. Finally experiments are conducted to demonstrate the effectiveness of our model and algorithm.

This study examines the acute, subacute (overnight), and chronic (7-day) effects of intracerebroventricular (i.c.v.) administration of r-metMuLeptin on insulin sensitivity and systemic glucose turnover in conscious unrestrained rats (body weight, 250 to 300 g). Under postabsorptive conditions, acute i.c.v. leptin ([AL] 10 microg bolus) did not affect tracer (3-(3)H-glucose)-determined glucose production (GP) and utilization (GU) rates during the 2-hour hyperinsulinemic (2 mU x kg(-1) x min(-1)) euglycemic clamp. Chronic i.c.v. leptin ([CL] 10 microg/d for 7 days) administered by osmotic pumps markedly reduced the daily food consumption (P < .05), body weight (P < .05), and postabsorptive basal plasma glucose level (P < .01). During the glucose clamp, GP was markedly suppressed (55%) with CL (P < .001 v vehicle and pair-fed control groups). The insulin-induced increment in GU was significantly greater with CL (23.3 +/- 1.8 mg(-1) x kg(-1) x min(-1)) than with vehicle (16.9 +/- 0.2) and pair-feeding (17.1 +/- 0.6, both P < .001). Subacute i.c.v. leptin ([SL] 10 microg bolus) moderately but insignificantly decreased overnight food consumption (-18%) and body weight (-2.5 +/- 1.5 g). The glucose infusion rate during the final 60 minutes of the glucose clamp was 43% greater than for the vehicle group (P < .0001). SL also significantly increased GU (P < .005) and suppressed GP (P < .05) during the glucose clamp. Thus, we conclude that i.c.v. administered leptin has strong actions on the central nervous system that result in significant increases in insulin sensitivity and systemic GU, and these effects are achieved as early as overnight after leptin administration.

The rheological behavior of poly(lactide) samples, with different levels of crystallinity, was investigated. The dynamic shear storage and loss modulus were obtained as a function of temperature at 1 rad/s. From the glassy to the rubbery region, the dynamic shear modulus decreased more than two decades for the initially amorphous poly(lac-tide) (containing 1% of D-lactide) and about one decade for the annealed (semicrystaJ-line) sample. The dynamic shear modulus data showed that the crystallization rate increased with a decrease of D-lactide in poly(lactide) and an increase of talc (a nucleating agent) in the sample. The steady-state and dynamic shear viscosity were measured at 210°C. The results indicated that the Cox-Merz rule can be used to relate the dynamic shear viscosity to the steady-state shear viscosity. A master curve for the amorphous poly(lactide) was obtained, using the time-temperature superposition principle. The result showed that the temperature dependence of the shift factor ca...

Scheduling is a key factor for manufacturing productivity. Effective scheduling can improve on-time delivery, reduce inventory, cut lead times, and improve the utilization of bottleneck resources. Because of the combinatorial nature of scheduling problems, it is often difficult to find optimal schedules, especially within a limited amount of computation time. Production schedules therefore are usually generated by using heuristics in practice. However, it is very difficult to evaluate the quality of these schedules, and the consistency of performance may also be an issue. In this paper, near-optimal solution methodologies for job shop scheduling are examined. The problem is formulated as integer optimization with a “separable” structure. The requirement of on-time delivery and low work-in-process inventory is modelled as a goal to minimize a weighted part tardiness and earliness penalty function. Lagrangian relaxation is used to decompose the problem into individual part subproblems with intuitive appeal. By iteratively solving these subproblems and updating the Lagrangian multipliers at the high level, near-optimal schedules are obtained with a lower bound provided as a byproduct. This paper reviews a few selected methods for solving subproblems and for updating multipliers. Based on the insights obtained, a new algorithm is presented that combines backward dynamic programming for solving low level subproblems and interleaved conjugate gradient method for solving the high level problem. The new method significantly improves algorithm convergence and solution quality. Numerical testing shows that the method is practical for job shop scheduling in industries.

To retrospectively investigate the role of (18) F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for the diagnosis and therapeutic response in relapsing polychondritis (RP) patients.(18)F-FDG PET/CT findings were reviewed in six RP patients. The initial scans were performed for all patients, follow-up scans were performed during steroid therapy for five patients. Changes in the abnormal lesions and the maximal standard uptake value (SUVmax) were analyzed.The initial PET/CT scans revealed intense FDG uptake in the cartilages for all six patients. The lesions of abnormal FDG uptake were tracheal/bronchial cartilage (n = 4), costicartilage (n = 4), nasal cartilage (n = 3), cricoid cartilage (n = 3), auricular cartilage (n = 3), arytenoid cartilage (n = 3), thyroid cartilage (n = 2), hyoid cartilage (n = 1) and mediastinum lymph node (n = 1). The mean visual score and the mean SUVmax were 2.96 ± 0.20 and 4.10 ± 0.6. The intense uptake reduced or disappeared during steroid therapy for five patients, the mean visual score and the mean SUVmax were 1.58 ± 1.4 and 1.51 ± 1.4.(18)F-FDG PET/CT enables the acquisition of both morphologic and glucose metabolic of the related cartilage structures. It plays a valuable role in assessing almost all cartilage and detecting RP, which is a better selection of a biopsy site as well as therapeutic response monitoring.

This paper focuses on the bonding group online bandwidth allocation problem in DOCSIS3.0 network. Taking network maximization utility as the goal, an optimal model, which is the Bonding Group based rival service flow Set Utility Maximization (BG-SUM), is built firstly, and then a Bonding Group Online Bandwidth Allocation algorithm (BG-OBA) is proposed to perform fast near-optimal solution. By discretizing the utility functions of requests, the BG-OBA fast allocate bandwidth for service flows and then verifies the feasibility of the bandwidth redistributed to each channel in bonding group. The simulation results show that the convergence speed of BG-OBA is faster than 0-1 integer programming, and the total utility is close to the theoretical optimum, hence it is practical for online bandwidth allocation

Network virtualization is an important technique to allow multiple customized networks to cohabit on a shared substrate network. In order to put the network virtualization into practice, the virtual network embedding (VNE) problem that searching an efficient mapping of a virtual network request onto substrate network resources should be solved primarily. Since the VNE problem is known to be NP-hard, previous work focused on designing heuristic-based algorithms. In this paper, we proposed the nodes clustering and dynamic service balance awareness based virtual network embedding (NC-DSBA) that employs the divide-and-conquer strategy along with the concurrence policy. Besides, the proposed NC-DSBA introduced a dynamic service balance algorithm to assist the embedding and improve the efficiency. The simulation results show that the NC-DSBA reduces the computational complexity, increases the acceptance ratio and revenue-cost ratio, and balances the loads of virtual nodes and links in substrate network in the long run.

Volatiles emitted by healthy, mechanically damaged, and weevil-infested Artemisia ordosica (Asteraceae) were obtained through a dynamic headspace method and analysed by automatic thermal desorption/gas chromatography/mass spectrometry (ATD/GC/MS). Twenty-eight compounds in all were identified, and the qualitative as well as quantitative differences were compared. The green leaf volatiles 2-hexenal, (Z)-3-hexen-1-ol, 2-hexen-1-ol, 1-hexanol, and (Z)-3-hexen-1-ol acetate were present in all of the damaged plants, but in relatively lower portions when plants were infested by the weevil Adosopius sp., while the terpenoids alpha-copaene, beta-cedrene, and (E,E)-alpha-farnesene and the ester methyl salicylate were only present in weevil-damaged plants. The volatiles from healthy and weevil-infested leaves were dominated by D-limonene, whereas mechanically damaged leaves emitted beta-pinene as the dominant compound.

This paper designs an infrastructure to meet the resource requirements, and more importantly, the QoS (quality of service) requirements for networked multimedia services. Learning from the successful experiences of distributed systems, the infrastructure deploys clusters of devices at the edge to improve the probability for end users to get satisfying QoS, and a two-layer management architecture is adopted accordingly. Moreover, a resource supply method based on virtualization and resource attributes is proposed. In the method, virtualized resources are packed and classified according to their purposes and functions, and each classification defines a minimum granularity, named service unit, to supply resources. Finally, to isolate traffic influence and guarantee network performance, each service is running on its isolated virtual network environment. The paper also presents the prototype system, and evaluates the feasibility and availability of it through experiments.

Web caching is a well-known strategy for improving the performance of web systems. The key to better web caching performance is an efficient replacing policy that keeps in the cache popular documents and replaces rarely used ones. When coupled with web log mining, the replacing policy can more accurately decide which documents should be cached. In this paper, we present a PLSA based prediction model to predict the user access patterns and interest to extend the well-known NGRAM-GDSF caching policy. Extensive experiments are conducted on the publicly available web logs datasets. The result shows that our approach gets better web-access performance.

In this paper, we present an efficient authenticating mechanism for supporting full interactive functions of video streaming. The server stores multiple versions of the same video for different playback speed. Our mechanism uses a tree-based structure to amortize frame level signature, merges multiple authenticating paths into this structure according to the frame chosen result of the video's different versions, and piggybacks erasure encoded authenticating information on packets. In addition, we analyze its performance compared with traditional tree chaining and erasure coding based schemes. The delay of interactive functions, communication and storage overhead are reduced. Packet loss is also tolerated with high probability. Simulation results further demonstrate the effectiveness of the proposed mechanism.

To predict the availability state of a node in a distribution network, its history trace is usually used. Sometimes, some usage behavior patterns cannot be captured precisely from the insufficient trace, which may lead to unreliable predictors. In this paper, to alleviate the data sparseness problem, the nodes with the similar behaviors are clustered, and all history information in a same cluster is seen as another information source for any node in it. For each node, an N-gram model is used to train the predictor by the combination of the new source and the node's own trace. In addition, because it is hard to capture the trace of all nodes in large scale networks, such as P2P networks, a bagging based prediction algorithm is proposed, which can be applied in the distribution environment and relieve the effect of the noisy data. In our experiments, three datasets are evaluated. Results show that the prediction performance of our cluster based N-gram predictor is better than the results of several other predictors. And the bagging based prediction algorithm presents its validity in the distribution environment.

The prevalence of overweight and obesity in women of childbearing age is up to 60% in developed nations.1 We sought to determine whether maternal adiposity is associated with aortic wall thickening in newborns, prior to prolonged postnatal exposure to potential confounders; and if so, whether this association is independent of birth weight, a known risk factor for later cardiovascular disease. Twenty-three pregnant women, age 35.6 years (SD 4.8; range 27.0–44.6), were recruited at 16.3 weeks gestation (SD 2.2; range 11.4–20.6) from The Women's Hospital, Melbourne, Australia. Women who had quit smoking in the previous 6 months were excluded; however those who continued to smoke were not. Maternal height and weight were measured at study entry. Overweight and obesity was defined as a body mass index (BMI)≥25 kg/m2, which we believe will not …

In vivo hepatic phosphorus-31 magnetic resonance spectroscopy (31)P-MRS) provides non-invasive information about phospholipid metabolism.To delineate (31)P-MRS abnormalities in patients with chronic rejection and to characterize spectral changes by pathology.Sixty-six liver transplant recipients (18 with chronic rejection and 48 with normal graft function) and 38 controls (23 healthy volunteers and fifteen patients with biliary duct stricture) were studied with in vivo (31)P-MRS. All the data and peak values were calibrated and calculated by the software of spectroscopy analysis GE, and the pH values were calculated by the Malloy's formula, then the peak area ratios and altitudes of metabolites relative to adenosine triphosphate (β-ATP)and phosphate (Pi) were measured.(a) The peak area ratios and altitudes of PME and PDE in biliary duct stricture group and chronic rejection group were higher than those of healthy volunteer group and normal graft function group. Patients with chronic rejection had significant differences in the peak area ratios of PME: β-ATP (P0.05) and PDE: β-ATP (P0.05) and in the altitudes of PME: β-ATP (P0.05) as compared with the other groups. (b) The ratios of β-ATP/Pi decreased in biliary duct stricture group, while they increased in chronic rejection group. There was no difference between the four groups. There were similar changes in the ratios of PME/Pi, but there was significant difference between the chronic rejection group and the other three groups. (c) pH values increased in biliary duct stricture group and chronic rejection group, though the difference was not significant with the healthy control group. (d) Histological specimens showed focal loss of hepatocytes, degeneration, and hepatocytic atrophy.(31)P-MRS imaging is valuable in detecting the metabolism of the liver after transplantation, and suggests that further investigation of alterations in the phospholipid metabolism may be a useful future direction of research.

A semi-fuzzy c-means algorithm based on revised Euclidean distance was proposed to improve the real-time capability and precision in fault pattern classified. Effectiveness of threshold parameters on clustering was investigated, and then program steps were given. The example of fault diagnosis in an airborne fire control system BIT was developed. The results show that the new algorithm can recognize fault pattern adaptively and precisely.

This paper presents system-level modeling and simulation of force-balance MEMS comb accelerometers. The work focuses on the theoretical principles of the sense element and the interface electronics at first. Based on that, the parametric model of the sense element is established in this paper, and the simulation results of this model match well with the theoretical results, which can prove we can use the parametric model of the sense element to establish the system-level model of force-balance MEMS comb accelerometers. The system-level model of force-balance MEMS comb accelerometers including the parametric model of the sense element and the interface electronics is established in MATLAB. The simulation results show that the designed force-balance comb accelerometer has high sensitivity, wide range, low nonlinear distortion and wide bandwidth.

In distributed systems, the server placement problem in which a new server has to compete with existing servers for user requests is important in planning of constructing new business service sites. In addition to minimizing cost, competition-aware server placement also needs to maximize the benefit of building a new server. This paper proposes a Tabu Search approach to optimize the problem in general graphs. Results from the simulation experiments show that it do has a better performance than both of the Greedy Add and Greedy Remove algorithms.

The effects of multi-stage tidal flow(TF) and subsurface flow(SSF) wetlands on the treatment of sewage were compared. The results showed the removals of NH 4 +-N (ammonia), TN(total nitrogen), SRP(soluble reactive phosphorus), TP(total phosphorus), COD Cr (chemical oxygen demand) using the TF wetland increased by 22%, 5%, 1%, 1% and 5% respectively than using the SSF wetland, which suggested the TF wetland was capable of largely enhancing nitrification but slightly on denitrification. The maximum rate of phosphorus and COD Cr removal took place in the 1st unit of both TF and SSF wetlands. The removal rate of NH 4 +-N in all units of the TF wetland was higher than the SSF wetland, while the first three units of the TF wetland were the dominated sink of TN accounting for 100% TN removal of the system; The 4th unit contributed negatively to TN removal because the nitrification was strengthened by higher substrate(NH 4 +-N) concentration, and the denitrification inhibited by lack of labile carbon.

In order to evaluate quantitatively the landscape stability of arid areas, a study area was selected in Yuli county of the middle and lower reaches of Tarim river. Remote sensing image data are the main data sources, the image data are processed by the support of RS and GIS technology. The study extracted 11 indices of landscape stability by FRAGSTATS software, and the standard matrix of these indices data are got using Z-Score method, then the comprehensive evaluation model of landscape stability is constructed by principal component analysis method. The study results showed that the range of comprehensive evaluation scores of Yuli's ecological landscape stability is 1.736, which indicated there is a great variation in ecological landscape stability of study area. The stability declines as the following order: forest land - water area- grass land- cultivated land - buildup land -unused land. The landscape stability is always the key scientific issues which should be solved urgently, the study on landscape stability has important theoretical and practical significance.

Multimodal transport system on container terminal is a complex stochastic system, so it is difficult to solve accurately by mathematical model. This paper presents a simulation-based optimization method for scheduling optimization of container terminal. First, from the aspect of whole operation process, based on Hybrid Flow Shop Scheduling problem a mathematical model is developed to optimize the operation sequence of quay cranes, yard trailers and yard cranes simultaneously. Second, a simulation optimization method of combining with the GA and simulation for operation scheduling in container terminals is proposed. Finally, case studies show that this method is applicable and effective to the problem of coordinating job sequence optimization.

the geological data system of the Central Asia is built to share the multi-sources, heterogeneous geological information on-line. The authors design the overall frame, the architecture and a functional module of general structure for the system. It uses PostgreSQL and PostGIS as the background spatial database, and uses Java, JavaScript as programming language to implement the system based on GeoServer in secondary development method. The goal of providing and sharing geological data is achieved so that users can browse these data through web interface easily. It facilitates researches on earth science.

In order to evaluate the influence of neighbors' quality to P2P streaming system's performance during scheduling, this paper establishes a markov chain based differential function model to analyze the relationship between peer's average startup delay and probability neighbors have wanted data as well as neighbors' available upload bandwidth. This paper also proposes a scheduling feedback algorithm, which learns real-time information of neighbors' data ownership as well as service capacity during data transferring and feeds back to overlay to help its optimization. The algorithm could help overlay discover possible better Qos neighbors when scheduling. Numerical analysis and experiment shows better quality neighbors can improve system's average startup delay significantly during scheduling.

Excessive warpage in flip-chip packages would raise concerns of process stability and reliability as well as customer acceptance concerns, making it critical to understand the thermal-mechanical mechanism of package warpage. In this paper, we report our comprehensive study focusing on the effects of the bump metallurgies, underfill material and its cure process on the package warpage. The warpage of the units with the Pb-free bump joints and its dependence on the underfill and its process were found significantly different from the units with other bump joints. The underline mechanism of package warpage formation is discussed.

Reducing server’s bandwidth pressure is one of the key problems in the designing of peer-to-peer video-on-demand system. In this paper, we analysis and model this problem via using the “pseudo sequence scheduling”, which is widely used by many peer-to-peer video-on-demand systems. We reveal the relations between the server bandwidth consumption, the cache size and the join speed of peers. This result shows its importance in the design of coordination strategy between peers in the system.

Directed Acyclic Graph (DAG) is a nature way of workflow description. One of the most important and challenging problems in the DAG workflow field is the QoS-constrained scheduling problem with the aim to minimize the cost. This paper proposes a new algorithm to tackle this problem. The algorithm proposed is based on tabu search and make some improvements. Subject to the deadline of the workflow, this algorithm has a lower execution cost than other existing algorithms. Simulation results prove the effectiveness and feasibility of the algorithm.

Content authentication is a critical issue for online multimedia systems. A new content authentication scheme based on optimal binary search tree (OBST) was proposed and evaluated to reduce the authentication cost. A balanced tree based approach, however, can not achieve optimal authentication cost when each element is accessed with different probabilities, so it’s not appropriate for a practical online multimedia system in which access of the contents is expected to obey Zipf’s law. We prove that an OBST based scheme achieves minimized expected authentication cost; we also compare the authentication cost of our scheme to that of a binary search tree (BST) and a red-black tree.

Previous work has shown that processor affinity is one effective way to improve the performance of SMP systems. A detailed analysis of cache characteristics on network processor is carried out. The result shows that network packet processing can also use cache affinity to gain performance improvements by reduce the miss rate of instruction cache and data cache. A schedule algorithm for multi-core network processor taking both load balancing and packet affinity into account is proposed, called BLA. BLA try to schedule packets from the same flow to the same core while keeping work load balanced between cores. The result shows that, BLA can reduce the number of missed cache access by 13%, while the load difference between cores is controlled within 2%.

Nowadays, most of multimedia information processing application systems are still realized in the monolithic and stove- pipe manner. This design pattern makes building and maintain- ing such multimedia systems intractable, costly and time-consum- ed. As a new style software design model, Service Oriented Architecture promises a more agile solution for developing large- scale Internet-based applications and has been widely accepted by the academic community and industries. However, the current service invoking method: SOAP does not apply to the multimedia area directly. This paper intends to solve this problem. Aiming at it, this paper proposes a new remote object access protocol based on SOAP which defines the correlative message format and the interaction model between the service and its client. According to the proposed approach, a service-composition-based prototype multimedia information processing system is constructed and the validity of our method is confirmed.

In our previous work [1], a Speech/Music classifier is proposed on the basis of the feature subset selection (FSS) tool and oblique decision tree induced by the algorithm OC1. In this paper, we endeavor to improve it by State transfer (ST) strategy whose aim is to refine the classification results, according to the fact that adjacent segments in one audio file have strong relevance to each other. The proposed algorithm is evaluated by a set of 5-to-11-minute 504 audio files of different types of speech and music in three Signal-to-Noise Ratio (SNR) levels: 30dB, 20dB and 10dB. The results show that ST strategy averagely improves the accuracy for music by 3.3% at 10 dB and 2.3% at 20 dB while keeping accuracy rate of speech almost unchanged. The speech classification rate is also lifted by 5.7% at 10dB on average.

The e-Support Vector regression Machine is a promising artificial intelligence technique, in which the regression algorithm has already been used in solving the nonlinear function approach successfully. Most users select parameters for an SVM by rule of thumb, so they frequently fail to generate the optimal parameters effect for the function. This has restricted effective use of SVM to a great degree. In this paper, the authors use genetic algorithm to solve the SVM parameters optimization problem. Simulation result shows that the method has high precision and possesses certain practical application significance.

Most current reputation models fail to calculate peers’ reputation accurately when there is little transaction history between the peers. To this end, this paper presents a trust model combing reputation and credential which accepts inputs of both feedback and credential. The model is based on reputation-based trust model, and according to the correlation of credential and reputation, the model can derive credential trust from the credential adaptively, then combine the credential trust and reputation to get the overall trust value. Analyses and simulations show that this model can improve the accuracy of the trust value computation significantly.

Data scheduling is the key issue in peer-to-peer streaming system, especially in peer-to-peer VoD system. This paper mainly focuses on data chunks’ priority definition of data scheduling in peer-to-peer VoD system. After carefully studying the meanings of regular rarest first scheduling and random scheduling, a Local-Rarest-Random-Heurist (LR2H) scheduling is proposed in order to fully use the resources of strong peers in the system. LR2H fully considers the meanings of rarest first priority and random priority. It brings abundant copies of data chunks in the system by using part of rarest priority and it also avoids the concentrate request in some data chunks which have same rarest priority by adding a random jitter, and then maximize total priority of every scheduling by using heuristic algorithm. Simulation proves that LR2H has achieved a scheduling effect about 30% better than normal rarest first or random scheduling.