Integrated Systems Engineering Research Articles

Spatio-temporal data fusion techniques for modeling digital twin City

ABSTRACT The digital twin city technique maps the massive city environmental and social data on a three-dimensional virtual model. It presents the operational status of physical world and supports intelligent city governance. However, the inefficient utilization of distributed data resources, and the lack of sharing and collaboration among multiple departments restrict the data formulation of digital twin city construction. This research proposes a new cross-domain spatio-temporal data fusion framework for supporting complex urban governance. It integrates the heterogeneous urban information generated and stored by different government departments using multiple-information techniques. A specified geographic base reflecting the real city status is established, using geographical entities with unified address as identifiers to encapsulate the urban elements information. We introduce a comprehensive urban spatio-temporal data center construction process, which has already supported multiple urban governance projects. The two distinct advantages in using this data fusion system are: 1) The proposed Bert+PtrNet+ESIM-based address mapping method associates the urban elements information to their corresponding geographic entities with 99.3% F1-Score on real-world dataset. 2) The Wuhan spatio-temporal data center operation illustrates the capability of our framework for complex urban governance, which significantly improves the efficiency of urban management and services. This integrated system engineering provides reference and inspiration for further spatio-temporal data management, which contributes to the future social governance in digital twin city platform.

Guest Editorial: Enhancing hosting capability for renewable energy generation in active distribution networks

Guest Editorial: Enhancing hosting capability for renewable energy generation in active distribution networks

The Impact of Industry 4.0 on the Automotive Business Models: A Successful Transition Through an Integrated System-Engineering and Strategic Perspective

The Impact of Industry 4.0 on the Automotive Business Models: A Successful Transition Through an Integrated System-Engineering and Strategic Perspective

Enhancement of deep violet InGaN double quantum wells laser diodes performance characteristics using superlattice last quantum barrier

Abstract The performance characteristics of InGaN double-quantum-well (DQW) laser diodes (LDs) with different last barrier structures are analyzed numerically by Integrated System Engineering Technical Computer Aided Design (ISE TCAD) software. Three different kind of structures for last quantum barrier including doped- GaN, doped- AlGaN and GaN/AlGaN superlattice last barrier are used and compared with conventional GaN last barrier in InGaN-based laser diodes. Replacing the conventional GaN last barrier with p-AlGaN increased hole flowing in the active region and consequently the radiative recombination which results in the enhancement of output power. However it caused increasing the threshold current due electron overflowing. For solving this problem, the last barrier structure altered with GaN/AlGaN superlattice. The simulation indicates that the electrical and optical characteristics of LDs with the superlattice last barrier, like output power, differential quantum efficiency (DQE) and slope efficiency, has significantly improved, besides the threshold current decreased. The enhancement is mainly attributed to the improvement of hole injection and the blocking electron overflowing which are caused by the reduction of polarization charges at the interface between the barrier and well, and electron blocking layer (EBL).

Raised Source/Drain (RSD) and Vertical Lightly Doped Drain (LDD) Poly-Si Thin-Film Transistor

The raised source/drain (RSD) structure is one of thin film transistor designs that is often used to improve device characteristics. Many studies have mentioned that the high impact ionization rate occurring at a drain side can be reduced, owing to a raised source/drain area that can disperse the drain electric field. In this study, we will discuss how the electric field at the drain side of an RSD device is reduced by a vertical lightly doped drain (LDD) scheme rather than a RSD structure. We used different raised source/drain forms to simulate the drain side electric field for each device, as well as their output characteristics, using Integrated Systems Engineering (ISE-TCAD) simulators. Different source and drain thicknesses and doping profiles were applied to verify the RSD mechanism. We found that the electric fields of a traditional device and uniform doping RSD structures are almost the same (~2.9 × 105 V/cm). The maximum drain electric field could be reduced to ~2 × 105 V/cm if a vertical lightly doped drain RSD scheme was adopted. A pure raised source/drain structure did not benefit the device characteristics if a vertical lightly doped drain design was not included in the raised source/drain areas.

Complexity, Systems Thinking and an Integrated Systems Engineering and Project Management Model

AbstractAlthough theory and guiding principles exist for the integration of systems engineering and project management, there does not appear to be a practical approach offered. With unproductive tension, discipline‐specific disparate processes and models, and persistent project failures, there is a need for a paradigm shift in the approach to this integration. This shift may be achieved through systems thinking and the use of an integrated management model that includes key linkages, a decision support system and system dynamics. The model presented in the current study provides a structured approach for multiple disciplines to address and manage product and project complexity through cross‐functional processes within an interactive dynamic model environment consisting of system, process and policy levers. The model is validated through application of a case study, literature review, surveys and interviews with industry experts. Use of the model provides for critical thinking and a multi‐disciplinary agile approach to help navigate complexity.

Systems Approach for Integration of Medicine and Therapy to Alleviate Pain of Human Musculoskeletal System

AbstractChronic pain and general physical discomfort are common symptoms for those seeking medical or physiotherapy treatment, as this relates to disorders found within the Human Musculoskeletal System (HMS). Since this system is highly complex and large in scale, clinical pain research has been confounded by many complex factors. To help alleviate chronic pain and other symptoms, Asian countries such as Japan, India and China have developed various traditional medicine‐based exercise techniques over many years. Although some are critical of these non‐orthodox medical approaches, others support the ‘overwhelming effort towards integrating alternative medicine into the mainstream’. In addition, these traditional techniques have been enhanced by recent scientific research into the HMS, undertaken by biomedical and mechanical engineers. The goal of our research is to establish a multidisciplinary approach integrating Systems Engineering, traditional oriental techniques, conventional medicine and related science. To pursue such an integrated approach this paper examines the therapist‐guided exercise for restoring human musculoskeletal balance called the Somatic Balance Restoration Therapy (SBRT). The SBRT is a simple but effective self‐exercise therapy with minimal assistance by a trained therapist. This therapy is analyzed by a Systems Engineering Approach using a mechanical engineering method by modeling the human body as a multi‐body subject to a static equilibrium condition. In addition, the wording has been rewritten in functional anatomical terms, enabling smooth communication between specialists of three different disciplines: therapy, conventional medicine and Systems Engineering. Examples will be given to demonstrate an integrated and systematic approach for identifying and remedying malfunctions within the HMS.

Integrating Program/Project Management and Systems Engineering in Practice

AbstractTwo practitioners who have experience integrating program/project management and systems engineering conducted two workshops titled ‘Integrating Systems Engineering, Project Management, and Quality Management’ as an INCOSE Enchantment Chapter tutorial and at the 2018 International Symposium (IS18), respectively. The workshops included presentations by the researchers about their organization's integration implementations followed by small group discussion exercises on topics/issues to consider when making integration decisions. Discussion topics were drawn from Rebentisch (Ed., 2017) and included motivations to integrate, organizational environments that support or inhibit integration, influencers and influence, integration metrics, and success and failure contributors. Each exercise concluded with out‐briefs of the small groups' observations, analyses, and recommendations to the collective. A synthesis of these observations, analyses, and recommendations provide the bases for this paper.

Stratosphere Observation Project Using a Small Balloon

Global warming continues to be a major concern around the world. The Integrated System Engineering Lab in Kyushu Institute of Technology (KIT) launched a small balloon to the stratosphere to study the ozone layer and greenhouse gases in order to understand global warming. It is a part of the Project Based Learning (PBL) course in KIT. The project mission objectives were to obtain photographs and video of the Earth surface and space and to perform measurement of the ozone gas (O3) and carbon dioxide gas (CO2) concentration in the atmosphere. The payload was launched into the stratosphere using a small balloon. After the balloon exploded at maximum altitude, the payload descended using a parachute before being recovered at sea. This project was divided into three (3) groups which were the structure, electrical and transmission team. Simulation of the flight path was performed to aid in recovering the payload. The project started from April 2016 and the balloon was successfully launched on October 30, 2016 from Saiki in the Oita prefecture of Kyushu, Japan. This paper will describe the procedure and result of this project.

H2O adsorption on amorphous In-Ga-Zn-O thin-film transistors under negative bias stress

Amorphous In-Ga-Zn-O thin-film transistors on flexible substrates were prepared to investigate H2O adsorption under negative bias stress (NBS). Shorter channel lengths induce a more seriously deteriorated NBS stability due to the stronger electric field near the source or drain electrode. With increasing channel width, the NBS instability increases to a peak and then slightly decreases. Integrated Systems Engineering Technology Computer-aided Design (ISE-TCAD) simulation confirms that the electric field near the source/drain in the etch-stop layer is relatively dense, especially near the channel edges. The electric field direction is also confirmed to have significant effects on the H2O adsorption process.

Investigation of a Hump Phenomenon in Back-Channel-Etched Amorphous In-Ga-Zn-O Thin-Film Transistors Under Negative Bias Stress

The hump phenomenon along with a negative shift of threshold voltage emerging in the transfer characteristics of amorphous InGaZnO thin-film transistors under negative bias stress was investigated. Higher measurement temperature and larger bias voltage can induce more and faster hole injection, thus leading to the increased parasitic ON-state current and more negative shift of the threshold voltage. Nevertheless, the parasitic current is independent of the channel width, illustrating that the parasitic channel originates from the hole trapping near the IGZO edges along the channel length. Integrated Systems Engineering Technology Computer-aided Design simulation confirms that the electric field near the IGZO edge is relatively dense, and the direction is more conducive for the holes in IGZO to inject into passivation (PV), to gate insulator (GI), or at PV/GI interface.

Super junction LDMOS with step field oxide layer

A novel step-oxide super junction-lateral double-diffused metal-oxide-semiconductor field-effect transistor (SOSJ-LDMOS) structure is proposed and optimised which allows the high breakdown voltage (BV) and low-specific on-resistance ( R on,sp ). The proposed structure overcomes the effect of thick field oxide formed by shallow trench isolation process in conventional buffer layer SJ-LDMOS ( N -buffered SJ-LDMOS), effectively enhancing the performance of the SJ-LDMOS. Thanks to the SO layer, a new electric field peak has been introduced in the surface electric field distribution, which makes the lateral surface electric field uniform in the off-state. Moreover, due to the thinner oxide layer, in the on-state the majority of electron current is accumulated near the top surface under the field plate and the thinner oxide layer also provides a wider current flowing path. In the virtue of integrated systems engineering (ISE) simulation, not only has the BV of SOSJ-LDMOS been increased, but also the R on,sp has been reduced simultaneously compared with the N -buffered SJ-LDMOS in the same drift length. In addition, when SOSJ-LDMOS and N -buffered LDMOS are at the same BV, the R on,sp of SOSJ-LDMOS is decreased by 26.3-38.9%, compared with the N -buffer SJ-LDMOS.

An Integrated Systems Engineering Method for Conceptual Design of Vehicle Handling Dynamics

The handling characteristics of road vehicles are important attributes that define a major part of its unique selling proposition. The engineering process of tuning vehicle handling dynamics is a challenging process due to the multitude of competing design requirements/parameters and requires a well-defined systematic approach. The primary objective of this publication is to describe an integrated system engineering method for the conceptual design of vehicle handling dynamics early in the product development process. A systems engineering-based simulation framework is described that connects subjective, customer-relevant handling expectations to higher-level, objective vehicle engineering targets and consequently breaks these targets down into subsystem-level requirements and component-level design specifications. A case study supporting this proposed system engineering method for vehicle handling design is also described in detail. The integrated systems engineering approach guides the engineering development process and provides insight into the compromises involved in vehicle handling layout, ultimately saving product development time and costs and helping to achieve a higher level of product maturity early in the design phase.

The effect of electron blocking layer on the performance of MQW oxide-confined intracavity-contacted InGaN-based vertical cavity surface emitting lasers

The effects of inserting AlGaN electron blocking layer (EBL) in the GaN-based vertical cavity surface emitting laser (VCSEL) structures on the LD performance has been investigated by Integrated System Engineering Technical Computer Aided Design (ISE TCAD) program software. The simulation results indicated that the performance characteristics of GaN-based quantum-well VCSEL were improved when the AlGaN EBL has been added. The effect of Al mole fraction (x) of the AlxGa1−xN EBL on the GaN-based VCSEL performance ranging from x=0.15 to x=0.25 was also studied. At x=0.15 to x=0.17, the threshold current was reduced. This reduction in the threshold current is due to the increase in the carrier confinement which is achieved by accumulated much more carrier close to the active region caused by the added AlxGa1−xN EBL. Above the x=0.17, the threshold current was increased which is attributed to the saturation of the carriers inside the active region that leads to increase in the leakage current. It also was due to that the EBL obstacle the hole flowing in the active region in the x>0.17. GaN-based VCSEL had the optimum performance with Al0.17Ga0.83N EBL; therefore, the effect of Al0.17Ga0.83N EBL thickness on the GaN-based quantum well VCSEL performance has also been investigated. According to the simulation results, the GaN-based VCSEL had the optimum performance when the EBL thickness was 25nm.

Erratum to: Influence of synovia constituents on tribological behaviors of articular cartilage

Teruo MURAKAMI, Seido YARIMITSU, Kazuhiro NAKASHIMA, Yoshinori SAWAE, Nobuo SAKAI 1 Research Center for Advanced Biomechanics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan 3 Department of Applied Science for Integrated System Engineering, Graduate School of Engineering, Kyushu Institute of Technology, 1-1, Sensuicho, Tobata-ku, Kitakyushu, 804-8550, Japan Received: 31 December 2012 / Revised: 18 February 2013 / Accepted: 16 March 2013 © The author(s) 2014. This article is published with open access at Springerlink.com

7.3.3 Integrating Systems Engineering with Project Management: a Current Challenge!

AbstractWith increasingly complex systems, relying on systems engineering as an interdisciplinary method to manage engineering processes is essential for companies. However, too many projects still fail and industrial groups have argued that these failures may be related to the managerial techniques used. Indeed organizational processes are more or less specifically mentioned in System Engineering standards but in practice project managers tend to rely more on their own standards which sometime set forth practices not in line with those of the System Engineering domain, hence the reported discrepancies which very often lead to project failure. Thus to improve the companies' competitiveness when developing new products, cooperation between processes related to system development and project management is key to achieve performance and success. This paper presents arguments which tend to support this theory and details two ongoing projects that aim at integrating both domains.

Correction: SEL1L Regulates Adhesion, Proliferation and Secretion of Insulin by Affecting Integrin Signaling

Figure 3 is an incorrect version of Figure 4 and the current Figure 4 is a duplicate of Figure 5. Please see the correct versions of Figure 3 and 4 here: Figure 3: Figure 4: There was an error in the Funding section. The correct funding information is as follows: This work was supported by funds from Ministero Istruzione Universita`e Ricerca, FIRB:RBIPO64CRT-005. G. R. Diaferia was the recipient of a Postdoctoral fellowship from the Juvenile Diabetes Research Foundation. V. Cirulli was supported by an American Diabetes Association Basic Research Award (#1-11-BS-28) and Juvenile Diabetes Research Foundation Research Grants #1-2005-1084 and #17-2011-620, and an LSDF Program Project grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was an error in the Competing Interests section. The correct Competing Interests statement is as follows: The authors have the following interests: Giuseppe R. Diaferia was employed for a limited period of time by Integrated System Engineering. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Modeling of parameters for nano‐scale surrounding‐gate MOSFET considering quantum mechanical effect

In this paper, an analytical surface potential and threshold voltage model for surrounding gate metal‐oxide semiconductor field‐effect transistor are proposed considering the quantum mechanical effect (QME). Considering variable Fermi potential along the channel, a simple relation between the eigen energies and the potential energy distribution is also provided for the first time. The variation of surface potential and the threshold voltage due to QMEs are computed analytically without using any numerical iteration technique in the model. QME on drain‐induced barrier lowering and threshold voltage roll‐off are also studied to provide a more accurate model. The proposed models are compared with existing surface potential and threshold voltage models and validated by comparing with the simulated results obtained from the 2D device simulator ATLAS of Integrated Systems Engineering Technology Computer Aided Design (ISE TCAD). Very good agreement of our model with TCAD is obtained for a wide variation of device parameters. Hence, the models will aid the designing of practical surrounding gate nano‐wire transistors. Copyright © 2013 John Wiley & Sons, Ltd.

Study on effect of quantum well number on performance characteristics of GaN-based vertical cavity surface emitting laser

The effect of number of quantum wells and quantum well thickness on the optical performance of InGaN vertical cavity surface emitting laser (VCSEL) was numerically investigated using Integrated System Engineering Technical Computer Aided Design (ISE TCAD) simulation program. The simulation results indicated that the output power and differential quantum efficiency of the double quantum well (DQW) laser were increased and threshold current decreased as compared to the single and triplet quantum wells VCSEL. Threshold current enhancement in the single quantum well (SQW) is attributed to the electron carrier leakage increasing from active layers because of the lower optical confinement factor. Simulation results show that in the double quantum well, the optical material gain and electron and hole carrier densities are approximately uniform with respect to the SQW and TQW. Also these results indicated that the electron current density in the DQW is the lowest. In the active region, electrical field decreased for the double quantum well because of the built-in electrical field reduction inside the quantum well. Finally the effect of quantum well thickness in DQW GaN-based VCSEL was investigated and it was observed that DQW VCSEL with 3nm quantum wells thickness had the optimum threshold current.

Effects of Cavity Length on Optical Characteristics of Deep Violet InGaN DQW Lasers

The performance characteristics and their dependence to cavity length of deep violet InGaN DQW lasers emitting at 390 nm have been investigated using the Integrated System Engineering Technical Computer Aided Design (ISE TCAD) software. The focus of simulation was on the study of optical properties which were carried out with varying cavity length from 200µm to 600µm. The simulation results indicated that the cavity length strongly affects the optical properties of the violet InGaN DQW laser. They showed that the parameters related to the output power such as optical intensity increases by increasing cavity length due to increase of applied current to the laser system. The results also indicated that the parameters such as optical material gain, stimulated and radiative recombination which are related to quantum efficiencies and laser performance decrease by increasing cavity length. It was shown that the laser structure with the longer cavity length has the lower optical loss.