Nach oben pdf A Performance Test Design Method and its Implementation Patterns for Multi-Services Systems

A Performance Test Design Method and its Implementation Patterns for Multi-Services Systems

A Performance Test Design Method and its Implementation Patterns for Multi-Services Systems

The worthwhile problems are the ones you can really solve or help solve, the ones you can really contribute something to. – Richard Feynman The service providers (SPs) are evolving their networks from legacy technologies to "fourth gen- eration" technologies which involves: (1) evolution of "traditional" wire-line telecoms standards to Voice over IP (VoIP) standards [DPB + 06], (2) evolution of Global System for Mobile Com- munications (GSM) and Code Division Multiple Access (CDMA) networks to 3rd Generation Partnership Project (3GPP) [3GP08] standards, e.g., Universal Mobile Telecommunications Sys- tem (UMTS) [KR07], (3) introduction of Wireless Local Area Network (WLAN) standards, e.g., IEEE 802.16 [oEI08], for both data and voice communications [RBAS04]. The current direction is to realise a convergence point of these trends into a set of technologies termed the IP Multi- media Subsystem (IMS). The concept behind IMS is to support a rich set of services available to end users on either wireless or wired User Equipments (UEs), provided via a uniform interface. Services are provided via an "overlay" technique over multiple service provider networks. The introduction of many new telecoms services and technologies is making it difficult to sat- isfy service quality requirements [Afu04], [TSMW06]. The growing number of users adds ad- ditional performance requirements to the upcoming telecommunication technologies. Therefore, the telecommunications service provider’s survival depends on its ability to prepare for changes in customer needs, as well as changes in regulation and technology [Jeu99].
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Design and implementation of a microservice for deletion of resources in the Multi-Agent Research and Simulation distributed system

Design and implementation of a microservice for deletion of resources in the Multi-Agent Research and Simulation distributed system

The marking and deletion services have a UnitTests project, part of each service’s solution, which contains all unit tests. All methods for both services have at least one unit test. The unit tests are conducted with the help of the xUnit tool [23]. Testing a single unit of work can become complicated if it has external dependencies. To deal with this issue, a mocking framework is used, Moq [24], which abstracts the external dependencies. This approach is very successful, because all dependencies are supplied through dependency injection. Appendix C shows a unit test, which tests the method for marking uploads. Internally the method retrieves the metadata for an upload from the metadata service, then checks if the upload is already marked. If not, the method performs a mark request, again to the metadata service. If an error is encountered or the upload is already marked, an exception is thrown. This method relies on several API calls to the metadata service. However, the metadata service is not accessible into the UnitTests project, it is available only in the MARS Cloud. To resolve this issue, the call and response to the metadata service are mocked. The mocked response returns an already marked upload. This test verifies if an exception is thrown when an already marked resource is encountered. This requirement is of high importance, because it removes the possibility that two services can manipulate the same resources at the same time.
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Design and Implementation of an Archive Microservice solution for the Multi-AgentResearch and Simulation Distributed System

Design and Implementation of an Archive Microservice solution for the Multi-AgentResearch and Simulation Distributed System

Microservice is a specialized implementation of Service Oriented Architecture(SOA) [5, chap- ter 3]. Service in an SOA is a functional unit that performs a specific business action (e.g., user authentication) accessed typically via a network that encapsulates its state and the operations performed on the data. Figure 2.4 illustrates an example of Service Oriented Ar- chitecture (SOA) in a distributed system where different services call each others interface to perform a particular action. Although microservices are built using the SOA paradigm, they have their differences. In a microservice, a service can be deployed and operated in- dependently because the services are designed to be more fine-grained with a single pur- pose, unlike SOA. Also, they are lightweight and domain driven [6] that makes the application simple to understand, develop, and test. The smaller set of services can be developed au- tonomously by different teams and be deployed quickly as they are usually lightweight in nature. This architecture promises to bring loose coupling by separating an application into smaller logical units.
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Design patterns for safety-critical embedded systems

Design patterns for safety-critical embedded systems

Recovery Block [68, 82, 84, 97] is a very well known fault-tolerant software method. It is based on fault detection with acceptance tests and backward er- ror recovery to avoid system failures. As in N-Version Programming, the Recov- ery Block Pattern includes N diverse, independent, and functionally equivalent software modules called “versions” from the same initial specification. These modules are classified into primary and N − 1 secondary versions, where the execution of any version is followed by an acceptance test. The primary version (Block) is firstly executed and followed by its acceptance test. Failure of the test will result in execution of a secondary alternate version (Recovery Block), which is also followed by an acceptance test. The last step is repeated until either one alternate passes its acceptance test or all alternates are executed without passing the test and an overall system failure is reported.
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Design, implementation, and error analysis of the multilevel summation method for dispersion

Design, implementation, and error analysis of the multilevel summation method for dispersion

In conclusion, it makes sense to verify the correctness of the estimate in Equation 5.107 experimentally. Experimental Verification of the Deficiencies To show that the results are not just limited to the dispersion case, numerical experiments are not just performed to check the validity of the estimate of Moore and Crozier for dispersion but also its electrostatic counterpart. The experimental setup was as follows: to simplify the investigation of the causes of the predicted differences in the approximation of the forces, all experiments need the exact same forces. To attain this, the nature of periodic boundary conditions was exploited; specifically, the force exerted on a particle is identical to the forces exerted on its images. The test systems for the scaling experiments were therefore created by reusing the first system ex- tended by its images. More precisely, the systems were obtained by incorporating the directly neighboring image domains of the previous system in x-, y- and z-direction in an alternating fashion. Thus, the number of particles doubled from experiment to experiment. The procedure for creating the test systems is schematically depicted in Figure 5.1.
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Design and implementation of multi-modal AR-based interaction for cooperative planning tasks

Design and implementation of multi-modal AR-based interaction for cooperative planning tasks

The system is controlled via Remote Procedure Calls (RPCs) which are basically just ap- plication functions triggered by messages received from other applications. Arguments and responses are passed as XML documents. Everybody familiar with XML messag- ing has experienced parsing issues sooner or later. Easy and generic patterns are not available. The ambiguous nature of string messages and the lack of high-performance string comparison methods usually cause growing if-then-else-if -constructions which are difficult to maintain when they have reached a certain size. We tackled this is- sue with the help of the Bielefeld Type Library which we extended with custom data types. The bigger idea is to keep parsing mechanisms transparent and just define data structure conversation from and to XML representation of a type. BTL classes encap- sulate the representation so that classes which want to use data types can use it easily. The workflow is reduced to initializing a template factory with the required data type, passing XML-strings to it and receiving the desired data object. Thanks to its object oriented design reuse of common data types is encouraged and sources of error are reduced.
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Change in test-taking motivation and its relationship to test performance in low-stakes assessments

Change in test-taking motivation and its relationship to test performance in low-stakes assessments

Another limitation concerns the consideration of students’ previous ability. Most previous research has found that the level of effort is not substantially related to high-stakes test scores when cognitive ability is controlled (Kong, Wise, Harmes, & Yang, 2006; Wise, Bhola, & Yang, 2006; Wise & Kong, 2005), but moderately related to low-stakes test scores (DeMars, Bashkov, & Socha, 2013). Our study used students’ grade in mathematics as a measure of students’ ability in mathematics prior to the test. We know that school grades account for not only intellectual capacity, but also for motivational and personality aspects; thus, grades are less objective than test scores on standardized achievement tests (Spinath, 2012). Ideally, we would like to control for prior knowledge with an additional measure from a high stakes test; however, this information was not available to us.
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A new method supporting decision-making in case of unclear scientific evidence : test implementation and simulation

A new method supporting decision-making in case of unclear scientific evidence : test implementation and simulation

nur eine eingeschränkte Entscheidungshilfe bietet, ist es angeraten, die in der eigenen bisherigen Praxis erfahrene, interne Evidenz für die Entscheidung zu nutzen. Das heißt, die Erfolge und Misserfolge, die im Zusammenhang mit einer Intervention erlebt werden, sollten für zukünftige Entscheidungen sinnvoll mit einbezogen werden. Beck-Bornholdt und Dubben [2] schlagen als mögliche Lösung einen Algorithmus vor, eine abgewandelte „never- change-a-winning-team“ Strategie. Die Idee dieses Algo- rithmus ist es, die Entscheidung, welche Intervention bei der nächsten Klientin mit einer betreffenden Diagnose angewendet werden soll, nach einem bestimmten Sche- ma zu treffen: Es soll jeweils aufgrund aller bisher (mit den beiden zur Wahl stehenden Interventionen) gemach- ten Erfahrungen entschieden werden. Diese Idee, auch bezeichnet als „play-the-winner rule“, bezieht sich auf Werke von Bayes [1] und Wold [11], wobei ähnliche Vor- gehensweisen bereits früher beschrieben worden sind [12]. Das Theorem von Bayes wurde für folgende Anwen- dungen vorgeschlagen:
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Towards a theoretical framework for human performance modelling within manufacturing systems design

Towards a theoretical framework for human performance modelling within manufacturing systems design

electronically over 12 weeks, and this particular figure illustrates a typical 8 hour production slot. Each data point shows the cycle time performance of an individual worker, and each cluster represents different operatives at the work station. Hence, the time series shows the extent to which performance varies for workers, and across workers, for a typical work station throughout an eight hour shift. Also evident in this graph are the operator break times, which also vary from those planned. Analysis of the data suggests that up to one third of the potential time for production is lost due to stoppages, extended breaks and disruptions to the flow of the line, many of which may be caused by worker behaviour. In this study, such variance was apparent across several workstations throughout the twelve week observation period. In this same plant, we also observed that the simulation models used to aid the design process typically over estimated assembly line performance by 15 to 20%. An important factor in this gap between real and anticipated performance of the system is undoubtedly the assumption that worker performance is somewhat standardized, which as figure 1 illustrates is not the case in practice.
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Advanced systems and services for ground vibration testing - Application for a research test on an Airbus A340-600 aircraft

Advanced systems and services for ground vibration testing - Application for a research test on an Airbus A340-600 aircraft

In March 2011, DLR and ONERA conducted a research campaign on A340-600 at Airbus. The objective of this campaign is to validate newly developed GVT strategies and to optimize the team work between DLR and ONERA. During the Ground Vibration Testing campaign, more than 650 channels are used for dynamics measurement. Eight LMS SCADAS III frames are linked together in master/slave configuration and distributed around and inside the aircraft. More than 16 shakers, for example, a very long stroke (50 mm) shaker with sine excitation force up to 1000 N specified by ONERA for better excitation capable to exhibit non-linear structural behaviors, are ready to connect to the aircraft in order to address the defined shaker configuration.
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A very High Performance Multi Purpose Computing Card for TM/TC and Control Systems

A very High Performance Multi Purpose Computing Card for TM/TC and Control Systems

Further, the Blackfin has two parallel interface ports for high speed data transfer to special chips. This is called the “Parallel Peripheral Interface”. It is a synchronous, half duplex, 16 Bit parallel interface to connect with e.g. A/D converter chips which support this interface. At the MFC, it is connected to the Expansion Interface Connector. Another feature of the CPU is to have two universal serial ports which are programmable to operate with various synchronous and asynchronous serial communication protocols, with up to half the speed of the system clock. There are several internal cache memories, 100 kByte assigned to each core and 128 kByte of shared memory for both cores. Depending on the selected chip derivate, the cores can be clocked with up to 600 MHz. Several MMU and DMA controllers support the cores with data transportation. The chip is able to control its own core voltage with a buck converter design with a few external components. With this feature and several run modes, it is possible to influence the total power consumption of the chip.
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A fixed-point based distributed method for energy flow calculation in multi-energy systems

A fixed-point based distributed method for energy flow calculation in multi-energy systems

Based on the interaction mechanism between subsystems, the unified Newton-Raphson method (UNM) has been cus- tomized for the EFC in electricity-gas systems [18], electrici- ty-heating system [19] and electricity-gas-heating systems [20]-[22]. In UNM, all EFC equations related to subsystems are simultaneously solved in a central place, so that the information of whole MES need to be shared and aggregated by a joint operator [23]. However, this approach is normally impractical, because electricity, gas and heating systems are generally managed by different entities. Due to the risk aversion and technical limitation of data management, subsystem operators tend to preserve the information privacy rather than collabora- tive data sharing [24]. Furthermore, without a robust and digi- talized energy system, intensively sharing large amounts of information in the UNM brings the increased communication burden, and the information sharing scheme threatens the ro- bustness of the UNM solution under the situation of possible data loss and incomplete dataset. In addition, a large number of variables in a MES will significantly increase the dimension of Jacobian matrix in the UNM, which will generally lead to slow or non- convergence. Consequently, it is necessary to develop a distributed and decentralized method for the joint EFC in MESs because 1) computationally, the dimension of the distributed
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System design and implementation of digital centric multi-standard transmitters

System design and implementation of digital centric multi-standard transmitters

7.1 Conclusion The high-speed data interface CAGv2 is implemented in UMIC TX2 and 3 as the first version (UMIC TX1) had severe issues in the data word alignment. The interface features Current Mode Logic (CML) transmission to increase the switching speed and to reduce the ground bouncing, an automatic DLL free bit alignment, 8b/10b encoding, an automatic initialization procedure. The ASRC in UMIC TX1 and 2 is called Clock-Domain Converter (CDC), a circuit which measures the delay between CLKBB and CLKSLOW with CLKLO (a clock running at the LO frequency). This ASRC increases the required data rate of the interface. As measurements show further issues in this architecture, it was replaced by a so called Pulse Shape Filter (PSF). It synchronizes the data of both clock-domains by means of a FIFO register and uses a generalized Farrow filter for implementation. Although the oversampling ratio of the PSF is fixed to an arbitrary value between 4 and 5, a proper selection of clock rates enables all required channels of the selected standards. Thereby, the ratio between CLKFAST and CLKSLOW remains integer and the power hungry UPsampler (UP) was replaced by a Cascaded Integrator-Comb (CIC) filter. A special boost stage in the CIC reduces the maximum output power degradation from 6 dB to 0.5 dB.
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A test method to assess operator safety using Closed Transfer Systems

A test method to assess operator safety using Closed Transfer Systems

Berichte aus dem Julius Kühn-Institut 196 279 Figure 1. Exposure of different dosimeters by performing a conventional filling using the induction hopper of a field crop sprayer (RAU D2) in dependency of different canister sizes Figure 2 shows the results of the second experimental setup. One can see that contamination on level of 75-percentile could only be found on the protective gloves and on the overall. A small contamination of the underwear between detection and determination limit was found in one case. This contamination is probably based on material effects as already mentioned above. There was no contamination on other dosimeters (visor, one-way laboratory gloves) used. From these results one can conclude that CTS can reduce the exposure of the operator significantly. If the CTS is mounted on the induction hopper instead on the dome shaft the expected exposure can be reduced further.
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Optimized Implementation of a Feature Detector for Embedded Systems Based on the Accelerated Segment Test

Optimized Implementation of a Feature Detector for Embedded Systems Based on the Accelerated Segment Test

is adapted for a whole vector. It would not make sense to keep the three-stages test, as the calcula- tion for the whole vector has to be done anyway if a single element is a corner. Instead of calculating anything concrete, which can later be used in the Vector-Detection, it tries to get a general overview of the vector’s content. Therefore, it uses a variation of the original high-speed test for the n = 12 FAST detector [ 20 ], which checks the 90°-pixels on the test pattern (offsets 0, 4, 8, 12 in Figure 3.5 ). To obtain an arc of 9 or more contiguous pixels, at least two of these four pixels are included. So the Abort Cri- terion examines all possibilities of two neighboring 90°-pixels. If for none of these pairs both exceed the nucleus p by at least the threshold t, then this ele- ment cannot be a corner. In the next step the decision is made whether the Vector-Detection is skipped for this vector or not. If none of the vector’s elements can be a corner, then the detection is skipped and the next vector is loaded from memory. If only the second half of the vector can contain one or more corners, then the Abort Criterion is repeated with a new 16 elements vector loaded with 8 pixels offset to
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Linear Transceiver Design for Full-Duplex Multi-cell MIMO Systems

Linear Transceiver Design for Full-Duplex Multi-cell MIMO Systems

multiple FD capable base stations (BSs) serve multiple mobile users operating in FD mode. The self- interference at the BSs and users, and co-channel interference (CCI) between all the nodes (BSs and users) in the system are both taken into account. We consider the transmit and receive filter design for sum-rate maximization problem subject to sum-power constraints at the BSs and individual power constraints at each user of the system under the limited dynamic range considerations at the transmitters and the receivers. By reformulating this non-convex problem as an equivalent multi-convex optimization problem with the addition of two auxiliary variables, we propose a low complexity alternating algorithm that converges to a stationary point. Since this sum-rate maximization results in starvation of users in terms of resources depending on the power of the self-interference and CCI channels, we modify the sum-rate maximization problem by adding target data rate constraints on each user, and propose an algorithm based on Lagrangian relaxation of the rate constraints.
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Concept and Realization of a Novel Test Method Using a Dynamic Test Stand for Detecting Persons by Sensor Systems on Autonomous Agricultural Robotics

Concept and Realization of a Novel Test Method Using a Dynamic Test Stand for Detecting Persons by Sensor Systems on Autonomous Agricultural Robotics

As an impact of research into industry, a dynamic test stand has been developed and realized on an agricultural farm for the very first time. Commercially available sensor sys- tems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This leads to the fact that it is a test that is determined by the naturally occurring environmental conditions and therefore cannot be planned. This corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. Due to the wide variety of environmental conditions, a sensor system will always need to be tested individually for the specific location of its autonomous robot. For this reason, the test stand is located between a silo installation and a cultivated agricultural area. Thus, the sensor systems are exposed to the general environmental conditions in the outdoor area, the environmental conditions in a silo plant and a cultivated field. In the silo, various particles of different sizes can be present in the air during silaging or feed intake, which can disturb the sensor systems. Dust formation during the summer months is, among other things, an interesting factor for sensor systems on a cultivated, agricultural field.
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Linear Transceiver Design for Full-Duplex Multi-cell MIMO Systems

Linear Transceiver Design for Full-Duplex Multi-cell MIMO Systems

wireless systems, MIMIO communications, optimization, and resource allocation in wireless networks. LUTZ LAMPE (M’02–SM’08) received the Dipl.- Ing. and Dr.Ing. degrees in electrical engineering from the University of Erlangen, Germany, in 1998 and 2002, respectively. Since 2003, he has been with the Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, BC, Canada, where he is currently a Full Professor. His research interests are broadly in theory and application of wireless, power line, optical wireless and optical fibre com- munications. He was the General (Co-)Chair of the 2005 IEEE International Conference on Power Line Communications and Its Applications (ISPLC), the 2009 IEEE International Conference on Ultra-Wideband (ICUWB), and the 2013 IEEE International Conference on Smart Grid Communications. He is currently an Associate Editor of the IEEE Wireless Communications Letters and the IEEE Communications Surveys and Tutorials. He has served as an Associate Editor and a Guest Editor of several IEEE Transactions and journals. He was a (co-)recipient of a number of best paper awards, including awards the 2006 IEEE ICUWB, the 2010 IEEE International Communications Conference, and the 2011 IEEE ISPLC. He is the Co- Edior of the book Power Line Communications: Principles, Standards and Applications from Multimedia to Smart Grid (John Wiley & Sons, 2016).
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A methodological framework for qualifying new thematic services for an implementation into SAFER emergency response and support services

A methodological framework for qualifying new thematic services for an implementation into SAFER emergency response and support services

In  the  FP‐7  GMES  SAFER  project  a  pre‐operational  service  for  emergency  response  and  emergency  support  products  was  implemented  to  reinforce  the  European  capacity  to  respond  to  emergency  situations. SAFER was not only focusing on “rapid mapping” and validated products during the crisis  phase  but  also  on  the  enrichment  of  the  service  with  a  wider  set  of  thematic  servicesFor  the  selection of new thematic services not only a high accuracy of products was of interest. Moreover, e.g.  service maturity, user interest and compliance to the SAFER operational model are important issues to  guarantee a validated service. 
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A set-based calculus and its implementation

A set-based calculus and its implementation

In this thesis, I use the set-based approach as the basis for a novel, small intermediate calculus, which allows to naturally embed concepts from higher-order functional, logic and concu[r]

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