Flexible Software Research Articles

Closed and automated CAR T cell lentiviral transduction by spinoculation

Background & Aim There is a growing need to close and automate chimeric antigen receptor (CAR) T cell therapy manufacturing. CAR T workflows depend on an ex vivogene transfer step for therapeutic efficacy. To streamline this step while keeping flexibility during process development, we introduced a stand-alone protocol software that uses existing Sepax C-Pro technology. SpinOculation C-Pro protocol software automates lentiviral vector (LVV) transduction and maintains a functionally closed system within a single-use disposable kit, and no viral entry enhancers are required. We present different user cases highlighting the flexibility of the SpinOculation C-Pro protocol software parameters to influence process development of LVV transduction efficiencies in combination with application-specific upstream processes and viral source. Methods, Results & Conclusion Methods Case 1 used frozen apheresis units from one healthy donor. Case 2 used fresh apheresis units from three healthy donors. Case 1 included thawing and washing of the apheresis unit with closed, automated processes.In both cases, T cell enrichment and activation were performed using manual, open processes on the first day of the workflow. Activation was continued in T-flask culture for the next 24 hours. Then, on culture day 1 in both cases, cells were split to perform parallel SpinOculation C-Pro process and manual transduction processes in static or shake flask for case 1 and in static flask for case 2. Table 2 shows the SpinOculation C-Pro protocol software parameters used in the two cases. Conclusion As these user cases demonstrate, SpinOculation C-Pro protocol software offers a solution for a closed, automated LVV transduction process step where transduction efficiency can be comparable to a manual, open process. The open, flexible software parameters provide a wide potential for process development and optimization by allowing users to vary multiple parameters . It is important to consider that many factors influence the performance that can be achieved. Notably, transduction efficiency is highly dependent on LVV source and the MOI. Moreover, the upstream preparation of T cells, as well as the method and reagents used to expand transduced T cells, can impact performance.SpinOculation C-Pro protocol software completes our solutions to meet the growing need for fully automated workflow solutions for chimeric antigen receptor T cell therapies to help standardize processes and reduce the impact of donor variability. There is a growing need to close and automate chimeric antigen receptor (CAR) T cell therapy manufacturing. CAR T workflows depend on an ex vivogene transfer step for therapeutic efficacy. To streamline this step while keeping flexibility during process development, we introduced a stand-alone protocol software that uses existing Sepax C-Pro technology. SpinOculation C-Pro protocol software automates lentiviral vector (LVV) transduction and maintains a functionally closed system within a single-use disposable kit, and no viral entry enhancers are required. We present different user cases highlighting the flexibility of the SpinOculation C-Pro protocol software parameters to influence process development of LVV transduction efficiencies in combination with application-specific upstream processes and viral source. Case 1 used frozen apheresis units from one healthy donor. Case 2 used fresh apheresis units from three healthy donors. Case 1 included thawing and washing of the apheresis unit with closed, automated processes.In both cases, T cell enrichment and activation were performed using manual, open processes on the first day of the workflow. Activation was continued in T-flask culture for the next 24 hours. Then, on culture day 1 in both cases, cells were split to perform parallel SpinOculation C-Pro process and manual transduction processes in static or shake flask for case 1 and in static flask for case 2. Table 2 shows the SpinOculation C-Pro protocol software parameters used in the two cases.

Projeto de reforço para o pavimento flexível do anel viário da UFJF baseado no novo método de dimensionamento mecanístico-empírico nacional

O presente trabalho de pesquisa utiliza o novo programa de dimensionamento de pavimentos flexíveis no Brasil (MeDiNa), para o cálculo de reforço do pavimento do anel viário da Universidade Federal de Juiz de Fora visando o restabelecimento de propriedades funcionais. Esse pavimento é avaliado funcionalmente através de Levantamento Visual Contínuo Informatizado (LVCI) e ensaio de irregularidade longitudinal, e estruturalmente por meio de levantamento de deflexões realizado por equipamento FWD e abertura de poço de sondagem. Com os dados coletados na avaliação estrutural, é realizada a segmentação homogênea do trecho e uma retroanálise de dados para obtenção de parâmetros necessários ao referido cálculo. Após o devido dimensionamento chegou-se à conclusão de que a melhor solução de reforço é o recapeamento de toda sua extensão com a mistura asfáltica de projeto em espessura única de 5,0 cm, observando a aplicação de uma camada antirreflexão de trincas em alguns trechos.

A four-stage adaptive scheduling scheme for service function chain in NFV

Network Function Virtualization (NFV) enables the flexible software implementation of Network Functions (NFs) which is called Virtualized Network Function (VNF) and placed along the routing path of the network flow. A sequence of VNFs constitutes a Service Function Chain (SFC) to satisfy the processing requirements of flows. Since the SFC scheduling depends on the current network state and the dynamics of flows, it brings a great challenge to make an optimal SFC scheduling decision efficiently. In this paper, we present a Four-stage Adaptive Scheduling Scheme (FSASM) to make a trade-off between different scheduling goals and effects on network performance and management overhead. We design the specific mechanism for each stage when the network is in different workloads. Then, we prove the NP hardness of the optimization models in FSASM and propose a Minimum wEight Path Selection Algorithm (MEPS) with polynomial time complexity to realize a practical SFC scheduling. Moreover, we perform comprehensive experiments under different real-world topologies and network states. The results demonstrate that FSASM can achieve high network throughput and resource utilization as well as decrease the scaling frequency in highly dynamic network scenarios.

Low-Latency Segmented List-Pruning Software Polar List Decoder

As the first provably capacity-achieving codes, polar codes have been selected as the coding scheme for 5G enhanced mobile broadband (eMBB) control channels. Furthermore, if the bottleneck in decoding complexity is addressed, polar codes are still promising for long code length scenarios in the future with superior error-correcting performance. Considering the demand of cloud radio access network (C-RAN) in 5G system, the low-latency software polar decoder is studied in this paper. Two novel algorithms are proposed to reduce the latency of the successive cancellation list (SCL) decoding, including the segmented list-pruning (SLP) algorithm and the modified distributed sorting (MDS) algorithm. Moreover, the proposed SLP algorithm improves the decoding performance compared to existing segmentation schemes. In terms of the software implementation, our decoder is nearly $20\%$ faster than the state-of-the-art flexible software polar list decoder.

LPWAN Technologies: Emerging Application Characteristics, Requirements, and Design Considerations

Low power wide area network (LPWAN) is a promising solution for long range and low power Internet of Things (IoT) and machine to machine (M2M) communication applications. This paper focuses on defining a systematic and powerful approach of identifying the key characteristics of such applications, translating them into explicit requirements, and then deriving the associated design considerations. LPWANs are resource-constrained networks and are primarily characterized by long battery life operation, extended coverage, high capacity, and low device and deployment costs. These characteristics translate into a key set of requirements including M2M traffic management, massive capacity, energy efficiency, low power operations, extended coverage, security, and interworking. The set of corresponding design considerations is identified in terms of two categories, desired or expected ones and enhanced ones, which reflect the wide range of characteristics associated with LPWAN-based applications. Prominent design constructs include admission and user traffic management, interference management, energy saving modes of operation, lightweight media access control (MAC) protocols, accurate location identification, security coverage techniques, and flexible software re-configurability. Topological and architectural options for interconnecting LPWAN entities are discussed. The major proprietary and standards-based LPWAN technology solutions available in the marketplace are presented. These include Sigfox, LoRaWAN, Narrowband IoT (NB-IoT), and long term evolution (LTE)-M, among others. The relevance of upcoming cellular 5G technology and its complementary relationship with LPWAN technology are also discussed.

Dynamic testing resource allocation modeling for multi-release software using optimal control theory and genetic algorithm

PurposeThe use of software is overpowering our modern society. Advancement in technology is directly proportional to an increase in user demand which further leads to an increase in the burden on software firms to develop high-quality and reliable software. To meet the demands, software firms need to upgrade existing versions. The upgrade process of software may lead to additional faults in successive versions of the software. The faults that remain undetected in the previous version are passed on to the new release. As this process is complicated and time-consuming, it is important for firms to allocate resources optimally during the testing phase of software development life cycle (SDLC). Resource allocation task becomes more challenging when the testing is carried out in a dynamic nature.Design/methodology/approachThe model presented in this paper explains the methodology to estimate the testing efforts in a dynamic environment with the assumption that debugging cost corresponding to each release follows learning curve phenomenon. We have used optimal control theoretic approach to find the optimal policies and genetic algorithm to estimate the testing effort. Further, numerical illustration has been given to validate the applicability of the proposed model using a real-life software failure data set.FindingsThe paper yields several substantive insights for software managers. The study shows that estimated testing efforts as well as the faults detected for both the releases are closer to the real data set.Originality /valueWe have proposed a dynamic resource allocation model for multirelease of software with the objective to minimize the total testing cost using the flexible software reliability growth model (SRGM).

AMLVaran: a software approach to implement variant analysis of targeted NGS sequencing data in an oncological care setting

BackgroundNext-Generation Sequencing (NGS) enables large-scale and cost-effective sequencing of genetic samples in order to detect genetic variants. After successful use in research-oriented projects, NGS is now entering clinical practice. Consequently, variant analysis is increasingly important to facilitate a better understanding of disease entities and prognoses. Furthermore, variant calling allows to adapt and optimize specific treatments of individual patients, and thus is an integral part of personalized medicine.However, the analysis of NGS data typically requires a number of complex bioinformatics processing steps. A flexible and reliable software that combines the variant analysis process with a simple, user-friendly interface is therefore highly desirable, but still lacking.ResultsWith AMLVaran (AML Variant Analyzer), we present a web-based software, that covers the complete variant analysis workflow of targeted NGS samples. The software provides a generic pipeline that allows free choice of variant calling tools and a flexible language (SSDL) for filtering variant lists. AMLVaran’s interactive website presents comprehensive annotation data and includes curated information on relevant hotspot regions and driver mutations. A concise clinical report with rule-based diagnostic recommendations is generated.An AMLVaran configuration with eight variant calling tools and a complex scoring scheme, based on the somatic variant calling pipeline appreci8, was used to analyze three datasets from AML and MDS studies with 402 samples in total. Maximum sensitivity and positive predictive values were 1.0 and 0.96, respectively. The tool’s usability was found to be satisfactory by medical professionals.ConclusionCoverage analysis, reproducible variant filtering and software usability are important for clinical assessment of variants. AMLVaran performs reliable NGS variant analyses and generates reports fulfilling the requirements of a clinical setting. Due to its generic design, the software can easily be adapted for use with different targeted panels for other tumor entities, or even for whole-exome data. AMLVaran has been deployed to a public web server and is distributed with Docker scripts for local use.

A Doppler Correcting Software Defined Radio Receiver Design for Satellite Communications

We present a flexible software defined radio (SDR) receiver design for the reception and demodulation of satellite signals. The proposed SDR performs an online Doppler search, as well as a code-rate and code-phase search online. The use of graphics processing units (GPUs) allows the radio to compensate Doppler offsets and achieve symbol synchronization in real time. This eliminates the need for a priori information on the satellites position and velocity to perform Doppler compensation on the downlink. To successfully utilize the enhanced computational power of graphics processing units (GPUs) and achieve real-time performance, we utilize acausal batch based signal processing, which allows for the use of fast convolution algorithms. These can efficiently be parallalized and run on GPUs. The Doppler search and demodulation is done by using matched filters. This allows one to adapt the demodulator to work for many modulation schemes by merely changing the set of filters. The demodulator itself essentially works as a batched correlation receiver. Additionally, the proposed SDR can decode signals from multiple antennas that are located at geographically spread ground stations simultaneously. The decoded bits are compared using soft decisions. This can greatly increase the rejection of local burst interference as well as polarized interference and tracking signals that rotate in polarization.

Assessment and Design of Steel frame Structure, consists Performance of Connection Joints with Tekla & Staad Pro

Steel offer the range of advantages to the structure Industry. The erudition of steel gives architects, and the freedom was to achieve the most ambitious visions. Steel is also one of the most sustainable construction materials, building owners naturally value the flexibility of steel buildings in addition the value of benefits they provide. Steel is ideal for modernization, reconfiguring, extending or adapting with minimal disruption. The conception of design analysis as well as modelling of steel structures is the most up-to-date edition in the civil engineering field. It is necessary to model a steel structure but if it is also analysed during its modelling then there will not be any chances of failure. Tekla structures are powerful and flexible software for all structural projects. Flurry up our construction work with an enormous of standard connections for all structural projects. In construction field, we create a evident, constructible 3D model of any steel structure from everyday industrial and commercial buildings to stadiums and high rise buildings. This project dealing with manual connection designing by using of Standards (ISO, AISC, AWS etc..). As well as considering of OSHA rules. Implemented manual designing and modelling by using of Tekla software. And the connections are an important part of steel structure like beam to column connections, moment connections. And are designed more conventionally than any individual members. The aim of this project work is to analyse a 7-storeyed commercial building for different load combinations using STAAD Pro software. And behaviour of connection of bolts.

TopoFilter: a MATLAB package for mechanistic model identification in systems biology

BackgroundTo develop mechanistic dynamic models in systems biology, one often needs to identify all (or minimal) representations of the biological processes that are consistent with experimental data, out of a potentially large set of hypothetical mechanisms. However, a simple enumeration of all alternatives becomes quickly intractable when the number of model parameters grows. Selecting appropriate dynamic models out of a large ensemble of models, taking the uncertainty in our biological knowledge and in the experimental data into account, is therefore a key current problem in systems biology.ResultsThe TopoFilter package addresses this problem in a heuristic and automated fashion by implementing the previously described topological filtering method for Bayesian model selection. It includes a core heuristic for searching the space of submodels of a parametrized model, coupled with a sampling-based exploration of the parameter space. Recent developments of the method allow to balance exhaustiveness and speed of the model space search, to efficiently re-sample parameters, to parallelize the search, and to use custom scoring functions. We use a theoretical example to motivate these features and then demonstrate TopoFilter’s applicability for a yeast signaling network with more than 250’000 possible model structures.ConclusionsTopoFilter is a flexible software framework that makes Bayesian model selection and reduction efficient and scalable to network models of a complexity that represents contemporary problems in, for example, cell signaling. TopoFilter is open-source, available under the GPL-3.0 license at https://gitlab.com/csb.ethz/TopoFilter. It includes installation instructions, a quickstart guide, a description of all package options, and multiple examples.

Flooding in the Mekong Delta: the impact of dyke systems on downstream hydrodynamics

Abstract. Building high dykes is a common measure of coping with floods and plays an important role in agricultural management in the Vietnamese Mekong Delta. However, the construction of high dykes causes considerable changes in hydrodynamics of the Mekong River. This paper aims to assess the impact of the high-dyke system on water level fluctuations and tidal propagation in the Mekong River branches. We developed a coupled 1-D to 2-D unstructured grid using Delft3D Flexible Mesh software. The model domain covered the Mekong Delta extending to the East (South China Sea) and West (Gulf of Thailand) seas, while the scenarios included the presence of high dykes in the Long Xuyen Quadrangle (LXQ), the Plain of Reeds (PoR) and the Trans-Bassac regions. The model was calibrated for the year 2000 high-flow season. Results show that the inclusion of high dykes changes the percentages of seaward outflow through the different Mekong branches and slightly redistributes flow over the low-flow and high-flow seasons. The LXQ and PoR high dykes result in an increase in the daily mean water levels and a decrease in the tidal amplitudes in their adjacent river branches. Moreover, the different high-dyke systems not only have an influence on the hydrodynamics in their own branch, but also influence other branches due to the Vam Nao connecting channel. These conclusions also hold for the extreme flood scenarios of 1981 and 1991 that had larger peak flows but smaller flood volumes. Peak flood water levels in the Mekong Delta in 1981 and 1991 are comparable to the 2000 flood as peak floods decrease and elongate due to upstream flooding in Cambodia. Future studies will focus on sediment pathways and distribution as well as climate change impact assessment.

Reviving Legislative Avenues for Gerrymandering Reform with a Flexible, Automated Tool

After seeking a “manageable standard” to apply to claims of partisan gerrymandering for over three decades, the Supreme Court has finally given up the chase, ruling that such claims are nonjusticiable. What is to be done? An extended history of successful congressional action suggests that the legislative pathway is more practical than often believed. Statutory requirements also make it possible to consider a broader suite of districting objectives. This paper presents a flexible new software and a framework for evaluating the practical implications of explicit objectives. I apply this approach to the conditions last required by Congress, generating equipopulous, contiguous, and compact districts. Among these conditions, the formal definition ofcompactnesshas proven contentious. Does it matter? I contrast the representation of the political parties and of racial and ethnic minorities under plans optimized according to 18 different definitions of compactness. On these grounds, the definitions are markedly consistent. These methods may be extended to alternative districting objectives and criteria.

DigApp and TaphonomApp: Two new open-access palaeontological and archaeological mobile apps

Two new paleontological and archaeological Android applications, DigApp and TaphonomApp, are presented in this manuscript. DigApp is intended to aid data collection, storage and management in archaeological and palaeontological excavations. DigApp allows easily recording of common field information such as spatial data and fossil identification data. Online and offline versions of DigApp were developed to fit all needs, and they can be modified according to the excavation particularities. TaphonomApp was created in order to assist taphonomists while carrying out detailed taphonomical evaluations both in the field and in the laboratory, making data collection quicker, homogeneous and overall, more efficient. DigApp and TaphonomApp are free, open-access and flexible software, that can be easily modified by any user (without the need of expertise in computing or coding) as explained in this paper. An in-depth guide on how to modify the apps is provided within this paper. DigApp and TaphonomApp have been used during palaeontological excavations carried out at one of the Batallones Butte vertebrate sites (Batallones-10, Middle Miocene) in the Madrid basin (Spain).

Reconfigurable Intelligent Surface-Based Wireless Communications: Antenna Design, Prototyping, and Experimental Results

One of the key enablers of future wireless communications is constituted by massive multiple-input multiple-output (MIMO) systems, which can improve the spectral efficiency by orders of magnitude. In existing massive MIMO systems, however, conventional phased arrays are used for beamforming. This method results in excessive power consumption and high hardware costs. Recently, reconfigurable intelligent surface (RIS) has been considered as one of the revolutionary technologies to enable energy-efficient and smart wireless communications, which is a two-dimensional structure with a large number of passive elements. In this paper, we develop a new type of high-gain yet low-cost RIS that bears 256 elements. The proposed RIS combines the functions of phase shift and radiation together on an electromagnetic surface, where positive intrinsic-negative (PIN) diodes are used to realize 2-bit phase shifting for beamforming. This radical design forms the basis for the world's first wireless communication prototype using RIS having 256 two-bit elements. The prototype consists of modular hardware and flexible software that encompass the following: the hosts for parameter setting and data exchange, the universal software radio peripherals (USRPs) for baseband and radio frequency (RF) signal processing, as well as the RIS for signal transmission and reception. Our performance evaluation confirms the feasibility and efficiency of RISs in wireless communications. We show that, at 2.3 GHz, the proposed RIS can achieve a 21.7 dBi antenna gain. At the millimeter wave (mmWave) frequency, that is, 28.5 GHz, it attains a 19.1 dBi antenna gain. Furthermore, it has been shown that the RIS-based wireless communication prototype developed is capable of significantly reducing the power consumption.

Telemonitoring System for Infectious Disease Prediction in Elderly People Based on a Novel Microservice Architecture

This article describes the design, development and implementation of a set of microservices based on an architecture that enables detection and assisted clinical diagnosis within the field of infectious diseases of elderly patients, via a telemonitoring system. The proposed system is designed to continuously update a medical database fed with vital signs from biosensor kits applied by nurses to elderly people on a daily basis. The database is hosted in the cloud and is managed by a flexible microservices software architecture. The computational paradigms of the edge and the cloud were used in the implementation of a hybrid cloud architecture in order to support versatile high-performance applications under the microservices pattern for the pre-diagnosis of infectious diseases in elderly patients. The results of an analysis of the usability of the equipment, the performance of the architecture and the service concept show that the proposed e-health system is feasible and innovative. The system components are also selected to give a cost-effective implementation for people living in disadvantaged areas. The proposed e-health system is also suitable for distributed computing, big data and NoSQL structures, thus allowing the immediate application of machine learning and AI algorithms to discover knowledge patterns from the overall population.

A low cost solution to monitor environmental parameters in industrial area perimeters

The monitoring of environmental parameters in active industrial areas where there exist potential sources of pollution, and even more so in the area of decommissioned or closure mining activities, is very important from the point of view of prevention of environmental accidents. In this paper, we propose a solution for the monitoring of the environmental parameters with the local acquisition and processing of the data and the transmission of alarm signals to a higher hierarchical level through the use of radio communications. A flexible hardware structure and software development concept are presented to be integrated into the national air quality monitoring network.

Внедрение систем автоматизированного проектирования (САПР) на машиностроительном предприятии: ограничения и возможности

The article highlights issues related to factors that affect the introduction of computer-aided design (CAD) systems in modern machine-building industries. The purpose of the work is to determine the main limitations and possibilities of using CAD in production and to consider the main trends in the development of system solutions for mechanical engineering problems. The theoretical basis of the work is data analysis and analytical study of the current state of proposals for CAD solutions. Electronic modeling systems allow not only to optimize the production process, reduce costs, but also are indispensable requirements for the competitiveness of modern engineering products on the world market. They allow you to carry out operational, remote interaction on the development and production of products, bringing it to the international market. Despite the variety of possibilities offered by CAD solutions from various companies and vendors, the request for its implementation by enterprises is very limited. The crisis state of the economy and industrial production is also not an incentive to implement such solutions. In this regard, it is necessary, on the one hand, to study in detail the evaluation of the effectiveness of implementing CAD technologies, and on the other hand - the most flexible software products that are adapted to the real capabilities and requirements of a particular enterprise, production process, and final product.

Методы приоритезации задач в гибких методологиях разработки программного обеспечения

The modern task prioritization methods that are used in flexible software development methodologies are discussed in the paper. Very flexible development methodologies such as Scrum, Kunban and others are currently the most popular because they allow making adjustments to it at any stage of a project, to improve the quality of the created product through daily monitoring of its creation and quickly release the first versions of the software. All task prioritization methods that are used in software projects de-velopment including flexible methodologies are divided into those that take into account the point of view of the development team and those that are based on various quantitative assessments, among which various metrics, expert opinions, points of view of those who are interested in the project, availa-ble classifications etc. Among the considered prioritization methods, which take into account the opin-ion of the development team, there are such popular and actively used nowadays methods, as MoSCoW, story map (User story mapping) and proactive improvement. Among the considered methods, based on quantitative assessment, is Kano's model, the method based on the creation of evaluation sheets, the method for estimating relative priorities for a set of functions offered by Carl Wigers and the method of structuring quality functions (Quality Function Deployment). Depending on the features of the project, customer requirements, the wishes of the development team and the other objective or subjective fac-tors, the project can use one or several prioritization methods at the same time or the combination of them. In addition, some of the considered methods can be used in short-term planning, the others – in the long-term, but there are those that can be used at each stage.

Model of support of development processes of intelligent decision-making support systems

The model of support of processes of development of intelligent decision-making support systems (IDMSS) is presented. The model contains a description of methods and tools to support the processes of development of IDMSS, the structure of the repository of decision-making methods, architecture and methodology of development of a typical IDMSS. The methodology is based on such principles: use of existing solutions, scalability, accessibility, independence from the subject area, informativeness. Adherence to these principles is ensured by the use of ontological, microservice and framework approaches, as well as approaches to rapid prototyping and methodology of flexible software development. The main methodological provisions of using the model are based on elements of Web technologies and development of information and analytical resources. The means of support of IDMSS development processes are described in detail – ontology of the field of knowledge “Decision-making support”, information-analytical resource, repository of decision-making support methods (DMS), methods of IDMSS development. As a framework of IDMSS it is offered to use an information-analytical resource which is constructed on the basis of ontology of subject area and methods of the used technology. With the help of services connected to the resource, which implement the stored DMS methods, the functionality of the developed IDMSS is provided. The language of descriptive logic is used to describe the model of complex support. Architectural solutions for which the developer and user interface are deployed in a separate container are presented. A solution for storing content and ontologies of the subject area in the repository with the organization of access through services is proposed.

Towards Wave Digital Memcomputing With Physical Memristor Models

In a more and more digital world, the protection of sensitive data is an essential challenge. Current cryptographic methods rely on one-way functions based on computationally challenging problems. However, there are several candidates for runtime efficient computing that might require new methods for data security. Among them are Universal Memcomputing Machines (UMM) for which a memristive circuit realization exists, where the eponymous element is a resistor with memory called memristor. While the original concept of UMMs is purely theoretical, we extend the state of the art by providing a thorough circuit theoretical analysis, utilizing models of real memristors and derive a highly flexible software emulator. The deployed memristor is an RRAM-cell which is known to have a rapid transition behavior, making it a suitable choice for runtime critical applications like UMMs. To obtain the emulator, we exploit the wave digital concept which is known to preserve passivity in a signal processing sense. The proper functioning is verified by solving an NP-complete subset sum problem.