Subsystem Technologies Research Articles

Systems Integration Framework for Hybrid-Electric Commuter and Regional Aircraft

System integration is one of the key challenges to bringing future hybrid-electric and all-electric aircraft into the market. In addition, retrofitting and redesigning existing aircraft are potential paths toward achieving hybrid and all-electric flight, which are even more challenging goals from a system integration perspective. Therefore, integration tools that bridge the gap between the aircraft and the subsystem level need to be developed for use in the conceptual design stage to address current system integration challenges, such as the use of space, the share between propulsive and secondary power, required level of electrification, safety, and thermal management. This paper presents a multidisciplinary design analysis (MDA) framework that integrates aircraft and subsystem sizing tools. In addition, this paper includes improved physics-based subsystem sizing methods that are also applicable to smaller, commuter, or regional aircraft. The capabilities of the developed framework and tools are presented for a case study covering the redesign of the DO-228 with a hybrid-electric propulsion system in combination with the electrification of its systems architecture and different subsystem technologies.

Impact of Liquid-Hydrogen Fuel-Cell Electric Propulsion on Aircraft Configuration and Integration

This study considers the aircraft configuration impacts of a liquid-hydrogen fuel-cell electric propulsion system when integrated into a single-aisle, transport-class aircraft having comparable performance capability of a Boeing 737-800. This study demonstrates that, given estimated developments in future components and subsystem technologies for a 2050 entry into service date, the design of an aircraft with a liquid-hydrogen fuel-cell–based propulsion system can be feasibly achieved while still meeting mission-level performance characteristics consistent with modern commercial aircraft throughout the anticipated lifetime of the aircraft. Key technologies that enable this are the purposeful integration of fuel cell thermal management, independent inlet compression to pressurize the air input to the fuel cells, and leveraging distributed electric propulsion advantages. Exploration into the impact of fuel cell power loss due to degradation is also presented. The results show a promising configuration of a liquid-hydrogen fuel-cell–based commercial aircraft to serve as a feasible replacement of narrow-body transport aircraft to help meet climate goals set for the aviation industry.

Intermodal Terminal Subsystem Technology Selection Using Integrated Fuzzy MCDM Model

Intermodal transportation is the use of multiple modes of transportation, which can lead to greater sustainability by reducing environmental impact and traffic congestion and increasing the efficiency of supply chains. One of the preconditions for efficient intermodal transport is the efficient intermodal terminal (IT). ITs allow for the smooth and efficient handling of cargo, thus reducing the time, cost, and environmental impact of transportation. Adequate selection of subsystem technologies can significantly improve the efficiency and productivity of an IT, ultimately leading to cost savings for businesses and a more efficient and sustainable transportation system. Accordingly, this paper aims to establish a framework for the evaluation and selection of appropriate technologies for IT subsystems. To solve the defined problem, an innovative hybrid multi-criteria decision making (MCDM) model, which combines the fuzzy factor relationship (FFARE) and the fuzzy combinative distance-based assessment (FCODAS) methods, is developed in this paper. The FFARE method is used for obtaining criteria weights, while the FCODAS method is used for evaluation and a final ranking of the alternatives. The established framework and the model are tested on a real-life case study, evaluating and selecting the handling technology for a planned IT. The study defines 12 potential variants of handling equipment based on their techno-operational characteristics and evaluates them using 16 criteria. The results indicate that the best handling technology variant is the one that uses a rail-mounted gantry crane for trans-shipment and a reach stacker for horizontal transport and storage. The results also point to the conclusion that instead of choosing equipment for each process separately, it is important to think about the combination of different handling technologies that can work together to complete a series of handling cycle processes. The main contributions of this paper are the development of a new hybrid model and the establishment of a framework for the selection of appropriate IT subsystem technologies along with a set of unique criteria for their evaluation and selection.

Multiple-Target Low-Thrust Interplanetary Trajectory of

is a medium-class interplanetary mission, selected by the Japan Aerospace Exploration Agency for potential launch windows in the first half of 2020s. The mission will demonstrate innovative spacecraft subsystem technologies, including a new type of ion engine for future missions. The mission will also collect scientific data through high-speed flyby observations and dust measurements from asteroid (3200) Phaethon and its related body (155140) 2005 UD, to understand their origin and reveal the content of extraterrestrial dust in the context of origin of life. The limited control authority on the spacecraft, the orbits of the target asteroids, and the specific mission requirements pose a challenging task for the trajectory design of . Multiple-target low-thrust optimal trajectories are explored in this paper to fulfill the goals of the mission. An effective methodology is presented to convert feasible impulsive transfer solutions into low-thrust initial guesses and combine with gravity-assist maneuvers to reveal new high-fidelity optimal trajectories in real ephemeris models. The early mission analysis results demonstrate multitudes of flyby opportunities that provide robustness against programmatic and operational delays in the mission schedule.

Application of Digital Technologies for Expansion Planning of Integrated Energy Systems

Active promotion of digital technologies in the energy sector requires a change in the principles of building energy systems, as well as the concept of their expansion planning. The functioning of infrastructural energy systems that are transforming as a result of the innovative development is fundamentally impossible without advanced information and communication technologies and intelligent digital tools. Energy systems are becoming sophisticated cyber-physical systems. At the same time, the problems of cybersecurity are exacerbating. The joint functioning of several types of energy systems in the form of a single integrated energy system provides new functional capabilities. The use of digital technologies in integrated energy systems provides the collection, processing, transmission and representing of information on all components of the system regarding all aspects of integration. Digitalization of integrated energy systems is carried out in the following two directions: application of digital technologies for individual subsystems for the purpose of their control; the use of digital technologies for technical and technological integration solutions in order to ensure coordination of subsystems and the implementation of system-wide goals. The adoption of digital technologies in integrated energy systems contributes to the organization of flexible, coordinated control of the expansion planning of such systems.

QoS Based IPTV over LTE-WLAN Heterogeneous Networks

Heterogeneous networks required IP Multimedia Subsystem (IMS) technologies to perform their control signaling and improve their communication services. However, the highest IPTV-QoS cannot be performed using IMS only as it cannot differentiate between IPTV video components. In this paper, we implement our IPTV-flow label technique in LTE-WLAN heterogeneous systems that used to improve QoS by providing IPTV sub traffic priority according to the network administrator policy. The proposed architecture has been implemented and analyzed using Opnet Modeler 17.5 software. The produced results demonstrate that IPTV users receive high definition video data with a variation in quantity in conformity with data priority by using Opnet 17.5 software.

BLUEPRINT: A novel approach to fusion reactor design

The European DEMO fusion power reactor (EU-DEMO) is still in the pre-conceptual design phase. The design strategy for the EU-DEMO hinges on investigating multiple reactor designs and technologies in parallel, progressively down-selecting these in the mid-2020s, in preparation for the conceptual design phase. The present implementation of the strategy centres around a baseline single-null design, which is configuration controlled and iterated approximately every two years. The majority of resources are dedicated to studying the baseline design; changing it is expensive, and takes months to do. Competing technologies for different sub-systems (e.g. blankets, magnets) are forced to co-exist within the same physical confines (CAD models), and conform to the same set of performance criteria. Meanwhile, the alternative reactor designs are only loosely defined, with no agreed set of parameters, no CAD models, and no formal framework for study.We argue that the EU-DEMO design strategy is best served by a more efficient implementation methodology which would enable more comprehensive exploration of the DEMO design space. We make the case for a change in approach to the design of DEMO-class reactors in Europe, and propose a solution which bears some resemblance to the present methodology, yet automates and accelerates the sequence of design and analysis activities when generating a design configuration.We present our preliminary attempts to demonstrate the feasibility of our idea, in the form of a new fusion reactor design code: BLUEPRINT. We demonstrate that the typical activities required to generate a DEMO design point can be sped up by four orders of magnitude—from months to minutes—paving the way for a rigorous and broad exploration of the design space.

A Survey on Aerial Swarm Robotics

The use of aerial swarms to solve real-world problems has been increasing steadily, accompanied by falling prices and improving performance of communication, sensing, and processing hardware. The commoditization of hardware has reduced unit costs, thereby lowering the barriers to entry to the field of aerial swarm robotics. A key enabling technology for swarms is the family of algorithms that allow the individual members of the swarm to communicate and allocate tasks amongst themselves, plan their trajectories, and coordinate their flight in such a way that the overall objectives of the swarm are achieved efficiently. These algorithms, often organized in a hierarchical fashion, endow the swarm with autonomy at every level, and the role of a human operator can be reduced, in principle, to interactions at a higher level without direct intervention. This technology depends on the clever and innovative application of theoretical tools from control and estimation. This paper reviews the state of the art of these theoretical tools, specifically focusing on how they have been developed for, and applied to, aerial swarms. Aerial swarms differ from swarms of ground-based vehicles in two respects: they operate in a three-dimensional space and the dynamics of individual vehicles adds an extra layer of complexity. We review dynamic modeling and conditions for stability and controllability that are essential in order to achieve cooperative flight and distributed sensing. The main sections of this paper focus on major results covering trajectory generation, task allocation, adversarial control, distributed sensing, monitoring, and mapping. Wherever possible, we indicate how the physics and subsystem technologies of aerial robots are brought to bear on these individual areas.

Current Progress of Tritium Fuel Cycle Technology for CFETR

Tritium fuel cycle technology is crucial for the successful development of China fusion engineering test reactor (CFETR) which aims to bridge the gap between a fusion experimental reactor (ITER) and a demonstration reactor. One of the major missions of CFETR is to realize tritium fuel self-sufficiency with a tritium breeding ratio over 1.0. In order to attain tritium self-sufficiency as well as ensure safe handling of tritium, it is important to establish a closed tritium fuel cycle. Therefore, a tritium plant which consists of various tritium processing systems and tritium safety systems is indispensable for the successful operation of CFETR. Since the mid-2000s, when China joined the ITER project, a series of R&D activities on tritium fuel cycle technology have been carried out. The current progress in terms of conceptual design of tritium plant, development of sub-system technologies and tritium related materials is presented in this paper.

창어 3호 개요 및 임무궤적 추정결과 분석

Chang'e-3 consisting of a lunar lander and exploration rover was launched on December 1, 2013 aboard a Long March 3B rocket flying from Xichang space launch center. Chang'e-3 was inserted into the lunar orbit after about a 5-day transit to the Moon and landed on the targeted landing site after orbiting around the Moon for 8 days. The successful landing of the Chang'e-3 gives a lot of help to analyze the future needs of the subsystem technologies and to figure out the trajectory from launch to lunar landing as well as operation sequences in the development of Korean lunar exploration is scheduled. Therefore, the configuration and analysis of overall mission of Chang'e-3 is performed based on the public information from the press and website. As a result, overall mission trajectory is reconstructed by solving boundary condition and then estimating control variable. Visibility status and eclipse status also analyzes so communication and power charge condition is as good as to operate lunar lander. Mass budget of the lander is derived using according to specific impulse.

Understanding product-service system innovation capabilities development for manufacturing companies

Purpose – Manufacturing companies are increasingly making efforts to combine products and services into integrated offerings. However, the companies’ success in such transformation is linked with the presence of structured routines and processes, which the authors conceptualize as product-service systems (PSS) innovation capabilities. The purpose of this paper is to address the important question of how manufacturing companies can systematically build PSS innovation capabilities and does its presence or absence significantly influence PSS innovation. Design/methodology/approach – This study is based on longitudinal data from an aerospace company, which acts both as an OEM providing through-life services for aircraft engines, as well as a developer of innovative subsystem technologies. Data has been collected over three years (2009-2012) and constitutes 40 in-depth explorative and semi-structured interviews with diverse respondents. For analysis of the data, the authors have used constant comparison technique leading to identification of three high-order categories. In addition, the authors gain from observations and secondary data which enable to achieve data triangulation and data validity. Findings – The results objectively depict an overview of how the case company developed PSS innovation capabilities, though progression of routines over three early PSS development stages. More specifically, the authors find evidence for development of formalized routines related to customer interaction and innovative organizational climate during need phase, cross-functionality, and network partnering during solution-seeking phase, and competence and business case development during solution development phase. As these routines become more structured within the case company, they forge a path for PSS innovation capabilities development. Originality/value – This study provides two distinctive contributions to emerging PSS literature. First, the authors propose and explain how PSS innovation capabilities are developed. Although prior studies acknowledge the importance of possessing specialized PSS innovation capabilities, limited studies have reported empirically how they are developed. Second, through adopting a longitudinal perspective, the authors reveal key routines and actions that drive PSS innovation during different development stages. To the knowledge, no prior study has combined insights from PSS literature and resource-based view to objectively explain capabilities development process.

Optical interconnects: recent advances and future challenges.

This focus issue is a collection of 17 invited papers showcasing the recent advances and the future challenges of optical interconnect technology. These papers represent multiple key areas that include the enabling devices and components, advances in the system and sub-system technologies as well as networking and its applications.

Torus-Topology Data Center Network Based on Optical Packet/Agile Circuit Switching with Intelligent Flow Management

We review our work on an intra-data center (DC) network based on co-deployment of optical packet switching (OPS) and optical circuit switching (OCS), conducted within the framework of a five-year-long national R&D program in Japan (∼March 2016). For the starter, preceding works relevant to optical switching technologies in intra-DC networks are briefly reviewed. Next, we present the architecture of our torus-topology OPS and agile OCS intra-DC network, together with a new flow management concept, where instantaneous optical path on-demand, so-called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Express Path</i> is established. Then, our hybrid optoelectronic packet router (HOPR), which handles 100 Gbps (25 Gbps × 4-wavelength) optical packets and its enabling device and sub-system technologies are presented. The HOPR aims at a high energy-efficiency of 0.09 [W/Gbps] and low-latency of 100 ns regime. Next, we provide the contention resolution strategies in the OPS and agile OCS network and present the performance analysis with the simulation results. It is followed by the discussions on the power consumption of intra-DC networks. We compare the power consumption and the throughput of a conventional fat-tree topology with the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> -dimensional torus topology. Finally, for further power saving, we propose a new scheme, which shuts off HOPR buffers according to the server operation status.

Technology readiness assessment of partitioning and transmutation in Japan and issues toward closed fuel cycle

This paper treats a technology readiness assessment of partitioning and transmutation in Japan and issues toward closed fuel cycles. The generic technology readiness level in this study is based on the definition in the Global Nuclear Energy Partnership: TRL 3 shows the status that critical function are proved and elemental technologies are identified; TRL 4 represents the level that the related technologies are validated at bench-scale in laboratory environment; and TRL 5 indicates the completion of the development related to the subsystem and elemental technologies. The reviewed technological area includes the partitioning and transmutation technologies for minor actinide cycle: fast breeder reactor, and accelerator driven system for minor actinide transmutation; partitioning processes; and minor actinide bearing fuels. The assessments reveal that the TRLs stay around the final step of concept development (TRL 3) and the first half step of elemental technology development (TRL 4) because each system requires more development of its elemental technologies. The fast breeder reactor is assessed to be at TRL 4 because critical experiments with americium and neptunium would be additionally required, and the technology for the accelerator driven system reaches TRL 3 due to several researches. Consequently, a common key issue is how nuclear calculation methodology will be validated for the MA-bearing-fuelled core; however, critical experiments with several kilogrammes of americium or more are difficult in the existing experimental facilities. On the other hand, engineering scale tests of the MA partitioning processes using actual spent fuel, and engineering scale of fabrication and irradiation tests with the separated materials are required to achieve the second half step of elemental technology development (TRL 5); however, they could be a massive investment. Therefore, laboratory-scale tests using actual material are proposed. The tests simulate a nuclear fuel cycle: partitioning actual spent fuels; and fabricating MA bearing fuels from the extracted materials; and then irradiating them. It should be that the tests advance technological readiness from TRL 4 to TRL 4+, which is a reasonable and feasible pathway.

Application of Sensor in Mining Machinery to Recognise Rock Surfaces

The success of automation applications in the mining industry traditionally has not been well. In many of these cases the benefits of automation have been advertised as the definitive solution to a wide variety of problems faced by the mining industry, such as increased safety and improved productivity. These applications have in many cases been introduced prematurely without adequate consideration of the rigors of the mining environment. As a result, effective technology has often been labeled as a failure before it has had a chance to demonstrate its true capability. Therefore, we believe that a major requirement is essential to develop automation technologies for mining systems or sub-systems, which needs minimal operator input requirement. This can be achieved in several ways. First, by narrowing the domain in which the automated mining system must operate such that less complex automation technology can be applied robustly. Alternately, more sophisticated control technologies are required that can react to the wider range of operating mining scenarios resulting from an uncertain, dynamic and very unstructured geological highly variable and unpredictable environment. Automation of shearer machines, with the help of an opto-tactile sensor, should make the machine capable to detect the coal-rock interface in the roof and the floor. In this article an attempt has been made to apply, in association with an existing shearer machine, a newly developed opt-tactile sensor to detect different types of material layers where a shearer machine can operate at the longwall face of underground coal mines. The proposed tactile sensor should be capable to detect different types of materials (coal, limestone, sandstone, and shell) recognizing their surface textures.

Improved compensation for a reduction stepper to meet the challenges for advanced packaging applications

Advanced packaging manufacturers require steppers that will provide solutions for the challenges encountered with new advances in wafer-level packaging technologies such as TSV, eWLB, silicon and glass interposers being utilized in leading edge mobile devices. Step and repeat photolithography systems capable of finer imaging with tighter overlay are being introduced to meet the challenging manufacturing requirements associated with the mix and match needed for volume production on larger wafers. A 2X reduction stepper with unique features incorporated that extend the range of compensation is necessary to achieve the tighter specifications needed for many advanced packaging applications printed on 300 to 450mm wafers. A high throughput projection optical system is used to expose circuit patterns from a reticle mask onto a substrate to image features with the optimal fidelity required for advanced packaging technologies. The camera incorporates 350–450nm light from a mercury arc lamp that is transmitted through the mask containing circuit patterns. The imaging field prints a large 52mm × 66mm area in a single exposure. These features enable a system to process wafers in fewer shots which result in higher throughput using lower power. Substrates are positioned with a precise X, Y, Θ stage by locating marks using an off-axis, bright field alignment system with fully trainable mark feature capability. The approach results in precisely placed features within a layer and from layer to layer without directly referencing the reticle. The integrated metrology and precision positioning subsystem technologies are combined with a low distortion projection lens and a wide range of adjustments, allowing the stepper to be integrated into a production line in a mix and match setup with other lithography systems. This equipment can be used to image critical layers on substrates while ensuring grid registration and alignment with other lithography systems that are also printing images in the same process line. Several important global and intra-field image placement relationships for devices requiring multiple layer patterning have been combined in the stepper matching correction software. Further adjustment to the tool can be made to improve overlay when incorporated with fab-wide yield management software for automated, real-time process control. The types of adjustments needed and techniques that can be applied to compensate for image placement errors over large areas are discussed.

Exploiting Heterogeneity for Energy Efficiency in Chip Multiprocessors

Heterogeneous multicores are envisioned to be a promising design paradigm to combat today's challenges of power, memory, and reliability walls that are impeding chip design using deep submicron technology. Future multicores are expected to integrate multiple different cores, including GPGPUs, custom accelerators and configurable cores. In this paper, we introduce an important dimension-technology-using which heterogeneity can be introduced in multicores to improve their energy-performance envelope. Specifically, we analyze the benefits of heterogenous technologies for processor cores and cache subsystems. We discuss two promising device candidates (Tunnel-FET and Magnetic-RAM) for introducing technological diversity in the multicores and analyze their integration in the processor and cache hierarchy in detail. Our analysis shows that introducing such a kind of heterogeneity can significantly enhance the performance and energy behavior of future multicore systems.

Components and Interconnection Technologies for Photonic-Assisted Routers Toward Green Networks

Photonic technology is an important solution to achieve power-saving routers/switches for green networks. As networking is a worldwide matter, and as the power consumed by routers and switches is rapidly increasing, power-efficient green networks have become a subject of great interest. The main issue of green networking is relieving the increasing power consumption, and photonic technologies will be effective for such issue. Photonic technologies are low-power external input/output (I/O) port and internal interconnection subsystem, which contributes to reduce power consumption of routers and switches. For the external I/O port, 100-Gb Ethernet technologies, which use high-speed and low-power optical and electrical CMOS devices, will be described. Also, we describe the power-saving photonic technologies for interconnection subsystems for network equipments. This optical interconnection (optical backplane) technology also requires optical and electrical devices, which are compact in size, high speed, and operate at low power. This interconnection realizes a highly energy efficient router/switch with advanced network functions.

Survey of worldwide pico- and nanosatellite missions, distributions and subsystem technology

This paper provides the results of a global survey of publicly known pico- and nanosatellite projects. The standard of CubeSats has boosted the development of nanosatellites by the end of the twentieth century and the total amount of projects has grown to about a hundred projects worldwide until August 2009. Pico- and nanosatellites can in general be distinguished from satellites with bigger mass ranges by their relatively short development time, low cost and usage of the latest technologies. To obtain a better understanding of the current technology level and applications of nanosatellites and to spot trends in the global development and growth of such projects, a survey is performed including almost all launched pico- and nanosatellites. A key finding is that most subsystem technologies used are rather advanced, except for the attitude control systems and performance characteristics of subsystems that depend on attitude control. Education and technology demonstration remain the most dominant mission objectives, although some scientific experiments have already been conducted.

Review of Modern Spacecraft Thermal Control Technologies

Originally created and developed for space applications, several commercial terrestrial technologies still permeate our society today. Examples include solar cells, Global Positioning Systems, and less expensive methods of carbon nanotube manufacture. Given a long and successful history of spinoffs, there might exist opportunities for the transfer of modern spacecraft thermal control technologies to terrestrial HVAC&R applications. First, this paper presents a broad overview of spacecraft thermal control. Next, a review of several modern spacecraft thermal control subsystem technologies is provided, each including an assessment of their potential use for terrestrial applications.