A pulse shaper with a picosecond leading edge on an impact avalanche transit-time diode

The possibility of shaping pulses by an impact avalanche transit-time diode operating in the abnormal mode is studied. A schematic diagram realizing the pulse shaping is presented. The results of environmental tests of the circuit and results of simulation demonstrating the efficiency of the proposed mode for obtaining pulses with picosecond leading edges are given.     

The impact of requirements on systems development speed: a multiple-case study in automotive

Requirements Engineering - Automotive manufacturers have historically adopted rigid requirements engineering processes. This allowed them to meet safety-critical requirements when producing a...     

Research on Glacier Change Monitoring in Nianchu River Basin

This study extracted the local glacier information over the Nianchu river basin in the Tibet in 1996 and 2005 by using ice index,snow index and water index of Landsat TM\|5 multi\|spectral images,and Synthetic Aperture Radar (SAR)intensity and coherence information of ERS\|1/2 and Envisat ASAR.The optimized features were determined by their classification accuracies based on Support Vector Machine (SVM)classifier.The result showed that the composition of multi\|spectral and SAR features could effectively discriminate the water and ice from other types,with overall accuracies of 84% and 85% in 1996 and 2005,respectively.Based on the thematic information of these two years,the changes of the local glacial area and boundary were detected.The result showed that the glacial area of the Nianchu river basin was reduced by 154.7 km²,which mainly caused by the climate warming.     

Development of glacier mapping in Indian Himalaya: a review of approaches

The paper reviews the status of glacier mapping with special reference to the Indian Himalaya. The review provides information on various satellite remote sensing data interpretation methods used with special emphasis laid on recent semi-automated algorithms used for glacier and debris-cover mapping, along with their limitations and challenges. Further, the pragmatic solutions on offer are discussed, and the emerging areas of glacier mapping research are highlighted. The review also touches – contribution of Survey of India (SOI) and Geological Survey of India (GSI) in the glacier mapping. Finally, it discusses the wider range of spatial and spectral domains in which remote sensing data helps to inventories glaciers. The review also identifies gaps in using the latest techniques like Unmanned Aerial Vehicles (UAVs) and machine learning algorithms to improvise on the ongoing efforts. At last, the review provides an exhaustive list of references on glacier mapping from the Indian Himalaya as benefit to readers.     

Visual impact analysis: a case study of a computer-based system

A system for computer-aided visual impact analysis (CAVIA) has been developed. The system can be considered as having landscape data, object data, visibility and visualization subsystems. A case study of the application of the system to the evaluation of alternative transmission line routes illustrates the techniques used for data collection, visibility and visualization. The integration of a digital terrain model (DTM) and associated derived data with Landsat satellite data to guide design work and construction planning is described. Validation of visualization and other aspects of the technique based on the constructed lines and current and future developments such as image mixing are discussed. The need for the system as an aid to planning and design problems is explained.     

The impact of visual layout factors on performance in Web pages: a cross-language study

Visual layout has a strong impact on performance and is a critical factor in the design of graphical user interfaces (GUIs) and Web pages. Many design guidelines employed in Web page design were inherited from human performance literature and GUI design studies and practices. However, few studies have investigated the more specific patterns of performance with Web pages that may reflect some differences between Web page and GUI design. We investigated interactions among four visual layout factors in Web page design (quantity of links, alignment, grouping indications, and density) in two experiments: one with pages in Hebrew, entailing right-to-left reading, and the other with English pages, entailing left-to-right reading. Some performance patterns (measured by search times and eye movements) were similar between languages. Performance was particularly poor in pages with many links and variable densities, but it improved with the presence of uniform density. Alignment was not shown to be a performance-enhancing factor. The findings are discussed in terms of the similarities and differences in the impact of layout factors between GUIs and Web pages. Actual or potential applications of this research include specific guidelines for Web page design.     

Assessment of tectonic activity in a seismically locked segment of Himachal Himalaya

Bilaspur (31° 23′ 586′′ N; 76° 45′ 178′′ E) lies in the south-west Himachal close to the Main Boundary Thrust (MBT). Neotectonic studies carried out in this region have revealed that the area is traversed by several faults, many of which may be active. GPS studies carried out in the entire Himalayan region indicate crustal shortening leading to strain accumulation. This is manifest in enhanced tectonic activity in the form of major and minor earthquakes. However, there are certain areas where stress release has not been witnessed and these areas can fail in large magnitude earthquakes in the future. Bilaspur lies in the zone of strain accumulation. This zone is building up a slip deficit at the rate of 14 ± 1 mm year^?1. In the light of these revelations and the fact that Bilaspur houses one of the biggest water reservoirs of the country an attempt has been made to assess the implications of these observations.     

Numerical study of droplet impact and coalescence in a microline patterning process

The droplet impact and coalescence on a substrate, which is applicable to the manufacture of microlines, is studied numerically by solving the equations governing the conservation of mass and momentum. The liquid–gas interface or droplet shape is tracked by a sharp-interface level-set method which is modified to account for the change between advancing and receding contact angles at the liquid–gas–solid interline. The numerical results show that the droplet impact and merging pattern depends significantly on the advancing and receding contact angles. Also, the effect of droplet spacing on the droplet motion is investigated to find the optimal conditions in manufacturing microlines.     

Numerical study on mechanical and hydraulic behaviour of blast-induced fractured rock

Engineering with Computers - In this research paper, smoothed particle hydrodynamics (SPH) with Johnson Holmquist damage model is adopted for modelling of the blast-induced fractures in Barre...     

The impact of corpus domain on word representation: a study on Persian word embeddings

Word embedding, has been a great success story for natural language processing in recent years. The main purpose of this approach is providing a vector representation of words based on neural network language modeling. Using a large training corpus, the model most learns from co-occurrences of words, namely Skip-gram model, and capture semantic features of words. Moreover, adding the recently introduced character embedding model to the objective function, the model can also focus on morphological features of words. In this paper, we study the impact of training corpus on the results of word embedding and show how the genre of training data affects the type of information captured by word embedding models. We perform our experiments on the Persian language. In line of our experiments, providing two well-known evaluation datasets for Persian, namely Google semantic/syntactic analogy and Wordsim353, is also part of the contribution of this paper. The experiments include computation of word embedding from various public Persian corpora with different genres and sizes while considering comprehensive lexical and semantic comparison between them. We identify words whose usages differ between these datasets resulted totally different vector representation which ends to significant impact on different domains in which the results vary up to 9% on Google analogy and up to 6% on Wordsim353. The resulted word embedding for each of the individual corpora as well as their combinations will be publicly available for any further research based on word embedding for Persian.     

Topographic controls on spatio-temporal snow cover distribution in Northwest Himalaya

The present study deals with spatio-temporal snow cover distribution in Northwest Himalaya (NWH) in a discourse on regional topography and prevalent climatology. Snow cover variation during 2001–2012 in NWH and eight major river basins was examined using MODIS data on board the Terra satellite. Slope match topographic correction was applied to eliminate the differential illumination effect on satellite imagery. The impact of cloud cover was removed by generating a 10-day maximum snow cover product. Annual and seasonal analysis shows a decreasing trend in snow cover area (SCA) over the entire NWH. Maximal SCA was observed in the windward river basins of the Lower and the Middle Himalayan zones and in the highly glaciated Shyok river basin of the Upper Himalaya. Monthly snow cover duration (SCD) maps revealed the effect of longitudinal variation as well as the strong influence of regional climatology and topography. The relationship of SCA with altitude and aspect was studied in all the river basins of NWH. The study shows a linear increment of SCA/D with increasing respect to elevation in all river basins. The maximum rate of SCA/D change with elevation was observed in the Jhelum river basin. In the Middle Himalayan Zone, an effect of basin orientation in regard to elevation was observed. Mean annual SCA at altitudes of up to 4500 m shows a decreasing trend. Seasonal analysis of aspect-wise snow cover shows that southern slopes have lower SCA during winter months. The difference in SCA between northern and southern slopes is even higher in summer and the monsoon period.     

Parallel bandwidth characteristics calculations for thin avalanche photodiodes on a SGI Origin 2000 supercomputer

An important factor for high‐speed optical communication is the availability of ultrafast and low‐noise photodetectors. Among the semiconductor photodetectors that are commonly used in today's long‐haul and metro‐area fiber‐optic systems, avalanche photodiodes (APDs) are often preferred over p‐i‐n photodiodes due to their internal gain, which significantly improves the receiver sensitivity and alleviates the need for optical pre‐amplification. Unfortunately, the random nature of the very process of carrier impact ionization, which generates the gain, is inherently noisy and results in fluctuations not only in the gain but also in the time response. Recently, a theory characterizing the autocorrelation function of APDs has been developed by us which incorporates the dead‐space effect, an effect that is very significant in thin, high‐performance APDs. The research extends the time‐domain analysis of the dead‐space multiplication model to compute the autocorrelation function of the APD impulse response. However, the computation requires a large amount of memory space and is very time consuming. In this research, we describe our experiences in parallelizing the code in MPI and OpenMP using CAPTools. Several array partitioning schemes and scheduling policies are implemented and tested. Our results show that the code is scalable up to 64 processors on a SGI Origin 2000 machine and has small average errors. Copyright © 2004 John Wiley & Sons, Ltd.     

Online dispute resolution in mediating EHR disputes: a case study on the impact of emotional intelligence

ABSTRACT

An Electronic Health Record (EHR) is an individual’s record of all health events that enables critical information to be documented and shared electronically amongst health care providers and patients. The introduction of an EHR, particularly a patient-accessible EHR, can be expected to lead to an escalation of enquiries, complaints and ultimately, disputes. Prevailing opinion is that Online Dispute Resolution (ODR) systems can help with the mediation of certain types of disputes electronically, particularly systems which deploy Artificial Intelligence (AI) to reduce the need for a human mediator. However, disputes regarding health tend to invoke emotional responses from patients that may conceivably impact ODR efficacy. This raises an interesting question on the influence of emotional intelligence (EI) in the process of mediation. Using a phenomenological research methodology simulating doctor–patient disputes mediated with an AI Smart ODR system in place of a human mediator, we found an association between EI and the propensity for a participant to change their previously asserted claims. Our results indicate participants with lower EI tend to prolong resolution compared to those with higher EI. Future research include trialling larger scale ODR systems for specific cohorts of patients in the area of health related dispute resolution are advanced.     

Distribution and Variation of Glacier Velocity in Himalayas based on ALOS PALSAR

Based on the 12 scenes ALOS PALSAR data from December 2007 to February 2010,combined with SRTM,we estimated the glacier velocityof the Himalayasin three periods by feature tracking method.The results show that glacier velocity of the winter of 2007,the summer of 2009 and the winter of 2009 were between 0~300 m·a^-1,and accumulation area of the glacier have obvious movement only in summer,butthe movement of the glacier tongue is obviousin any season.Long tongue glacier velocity decreasesslowlyalong the mainstream line,while the short tongue glacier velocity fluctuatesalong the mainstream line,and even increases.The glacier in east aspecthas the largest velocity.The glaciervelocity in southeast aspect and the southwest aspect are second,and glacier velocity is minimum in the north aspect.In addition to climatic factors,it also closely relates to terrain factors.In terms of the slope of the four aspects,the north aspecthas the smallest slope,andit is one of the main causes of the smallest glacier velocity in the north aspect.There is an inter-annual variation of glaciers,that is,mean velocity of glaciers increases in winter,and the increased velocities are between -5~18 m·(2a).The glacier with small areavaries greatly,and the glacier with large area varies little.Meanwhile,the glacier velocity also has seasonal variation.The overall velocity in summer is larger than that in winter.The velocity in mainstream line fluctuates strongly in summer,and there are many peaks,but velocity in winteris gentle.However,the seasonal variation of the mean velocity in mainstream line is not obvious.The inter-annual variation and seasonal variation of the four typical glacier velocities are similar to those of the glaciers in the study area.There is a close relationship between velocity and climate and the shape of the glacier.The characteristics of glacier advance and retreat are not obvious,and the glaciers in the study area are in equilibrium.     

The impact of learning styles on student grouping for collaborative learning: a case study

Learning style models constitute a valuable tool for improving individual learning by the use of adaptation techniques based on them. In this paper, we present how the benefit of considering learning styles with adaptation purposes, as part of the user model, can be extended to the context of collaborative learning as a key feature for group formation. We explore the effects that the combination of students with different learning styles in specific groups may have in the final results of the tasks accomplished by them collaboratively. With this aim, a case study with 166 students of computer science has been carried out, from which conclusions are drawn. We also describe how an existing web-based system can take advantage of learning style information in order to form more productive groups. Our ongoing work concerning the automatic extraction of grouping rules starting from data about previous interactions within the system is also outlined. Finally, we present our challenges, related to the continuous improvement of collaboration by the use and dynamic modification of automatic grouping rules.     

Evaluating the impact of an agile transformation: a longitudinal case study in a distributed context

Many software-development organizations have recently started to adopt agile practices in order to benefit from the improvements they clearly bring, in terms of production speed and software quality, for example. However, in a large, distributed organization, such as Nokia Siemens Networks, an agile transformation may be a long-term, complex process, and therefore, evaluating the benefits achieved, and measuring the success of the change, can be difficult, especially in the early phases of the transformation. This paper is based on the results of a case study on the impact introducing agile practices actually had in a large, software-development organization, part of Nokia Siemens Networks. The impact of this agile transformation was evaluated in terms of how well it succeeded in achieving the goals set by the management before the transformation started. This longitudinal study included two separate analyses, made at 6 monthly intervals, which measured what agile practices were really in use in the organization, and what effects, if any, were visible in terms of the goals which had been set by the management The 6 monthly analyses included defect data metrics and opinion surveys of the personnel directly involved in the transformation. The study showed two things: firstly, that the introduction of agile practices does have the beneficial effects that one would expect, and secondly, that, using this kind of study, it is not only possible to evaluate the impact that the adoption of agile practices has in a large, established software-development company, but also that the effects are visible at a surprisingly early stage.     

A preliminary study on the impact of a pair design phase on pair programming and solo programming

The drawback of pair programming is the nearly doubled personnel cost. The extra cost of pair programming originates from the strict rule of extreme programming where every line of code should be developed by a pair of developers. Is this rule not a waste of resources? Is it not possible to gain a large portion of the benefits of pair programming by only a small fraction of the meeting time of a pair programming session? We conducted a preliminary study to answer this question by splitting the pair programming process into a pair design and a pair implementation phase. The pair implementation phase is compared to a solo implementation phase, which in turn was preceeded by a pair design phase, as well. The study is preliminary as its major goal was to identify an appropriate sample size for subsequent experiments. The data from this study suggest that there is no difference in terms of development cost between a pair and a solo implementation phase if the cost for developing programs of similar level of correctness is concerned.     

Estimating the impact of residents with disabilities on the evacuation in a high-rise building: A simulation study

In this paper, we study how seriously residents with disabilities affect the evacuation of other residents in a 24-story high-rise building environment through an agent-based simulation model. In particular, we analyze the trends of the evacuation times in two population scenarios, homogeneous (i.e., only residents without disabilities) and heterogeneous residents (i.e., residents with and without disabilities), while we vary the size of populations and the compositions of disability types of residents. According to our experimental results, residents with disabilities significantly delay the evacuation process by causing congestion and blocking phenomenon. Our experimental results also indicate that the differences in the evacuation time of the homogenous and the heterogeneous population scenarios become more significant as the population size increases because of serious congestion from the increased population size and blocking from the increased proportion of the handicapped. Finally, we present regression models and controlled evacuation strategies that help evacuation administrators ensure the safe evacuation of all the residents by controlling the number of residents and evacuate residents with disabilities efficiently.     

遥感技术在现代冰川变化研究中的应用

传统的现代冰川变化研究主要以实地观测和经验公式来获得冰川的面积变化、体积变化和冰川表面运动速度,从20世纪80年代以来随着航空遥感光学图像、数字高程模型、雷达等新技术数据的不断出现和发展,借助遥感手段研究冰川的性质和特征、监测冰川的动态变化成为冰川学研究发展的重要趋势,也有效解决了现代冰川研究中高山区资料受限等问题。冰川面积变化的计算机自动解译方法主要有阈值法和雪盖指数阈值法、监督分类非监督分类法、比值阈值法等。阈值法和雪盖指数阈值法操作简单,但是在阈值选取方面不好把握;非监督分类法操作简单但限制因素较多;如果训练区选择准确,监督分类法分类结果比较精确;波段比值阈值法操作相对简单,精度准确,是目前运用最多的计算机自动分类方法。数字高程模型和雷达数据在冰川体积变化研究中的应用,较好地提高了传统方法的精度和适用性; 而且雷达数据具有不受大气传播和气候影响的特点,很好地弥补了遥感光学影像数据极易受云雪等影响的不足。高精度GPS和雷达数据的不断发展和应用在冰川表面运动速度的研究中起着不可替代的作用。 