On 3D Stacked IC Yield Improvement and 3D-DfT Test Architecture

Three-dimensional stacked ICs (3D-SICs) based on Through-Silicon Vias (TSVs) is an emerging technology. It provides heterogeneous integration, higher performance and bandwidth, and lower power consumption. However, 3D-SICs suffer from lower compound yield, especially those based on Wafer-to-Wafer (W2W) stacking. In addition, testability of such devices is still in its infancy stage. This thesis addresses these two challenges. To improve the compound yield of W2W 3D-SICs, a technique known as wafer matching will be used. It defines the best matching of top and bottom wafers from repositories of pre-tested wafers. The simulation results show that the compound-yield increase depends on (1) the number of stack tiers, (2) the number of dies per wafer, (3) the die yield, and (4) the repository size. Moreover, they demonstrate that, for realistic cases, relative yield increases of 0.5% to 10% can be achieved. The thesis also proposes a three-dimensional Design-for-Test (3D-DfT) architecture that solves the testability issue of of 3D-SICs. The architecture is based on a modular approach, in which the various dies, their embedded IP cores, TSV-based interconnect, and external I/O can be tested as separate units, before and/or after bonding. Furthermore, the architecture leverages existing 2D DfT already present in the design, and adds a die-level wrapper based on IEEE Std 1500 augmented with additional features in order to be able to deals with 3D-SIC challenges (e.g., to transport signals up and down through the stack). The architecture is implemented and the simulation results show that it provides the flexibility and the modularity is realized at the cost of less than 0.1% area overhead when considering large industrial chips. The architecture could serve as a basis for further standardization of DfT for 3D-SICs.Computer EngineeringMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc

Localization with Wi-fi fingerprinting: Towards indoor navigation on smartphones

GIS TechnologyOTB Research Institute for the Built Environmen

Benefits of linked data for interoperability during crisis management

Floodings represent a permanent risk to the Netherlands in general and to her power supply in particular. Data sharing is essential within this crisis scenario as a power cut affects a great variety of interdependant sectors. Currently used data sharing systems have been shown to hamper interoperability between stakeholders since they lack flexibility and there is no consensus in term definitions and interpretations. The study presented in this paper addresses these challenges by proposing a new data sharing solution based on Linked Data, a method of interlinking data points in a structured way on the web. A conceptual model for two data sharing parties in a flood-caused power cut crisis management scenario was developed to which relevant data were linked. The analysis revealed that the presented data sharing solution burderns its user with extra costs in the short run, but saves resources in the long run by overcoming interoperability problems of the legacy systems. The more stakeholders adopt Linked Data the stronger its benefits for data sharing will become.OTBArchitecture and The Built Environmen

A graph-matching approach to indoor localization using a mobile device and a reference bim

The presented method provides for a possibility to perform graph-based indoor localization, by comparing the topological structure embedded in a mesh model to the topological structure of a semantically rich reference model, specifically a BIM. However different in nature and structure, both input sources can be converted to a graph of similar calibre, such that they can be tested for a match. After a match between both graphs is found, the current position of the actor within the mesh model can be translated to the room found in the graph. This room is now connected to a room within the reference graph, for which the semantics are stored in the BIM. Returning these to the actor, a location description can be formed. Many indoor positioning methods have been developed, which can provide an actor with a relative geometric place. Most preferred are positioning systems not relying on a contingent system, which can be performed using a fusion of sensors embedded into a mobile device. Such a system found to perform sufficiently is VI-SLAM, simultaneously building a geometric place and tracking each pose and heading relatively. Its output is a mesh model, in which a viewshed of the indoor environment is built. Indoor localization however, entails finding a humanly interpretable qualitative description of a place, rather than a quantitative position in Euclidean space. In order to transcend such a position to a meaningful location, the context of an indoor environment has to be understood. As the interpretation of indoor space is different across the board, misalignment in data sources representing the indoor environment occurs. .Design InformaticsGIS Technologi

A DfT architecture for 3D-SICs based on a standardizable die wrapper

Process technology developments enable the creation of three-dimensional stacked ICs (3D-SICs) interconnected by means of Through-Silicon Vias (TSVs). This paper presents a 3D Design-for-Test (DfT) architecture for such 3D-SICs that allows prebond die testing as well as mid-bond and post-bond stack testing. The architecture enables a modular test approach, in which the various dies, their embedded IP cores, the inter-die TSV-based interconnects, and the external I/Os can be tested as separate units, which allows flexible optimization of the 3D-SIC test flow and provides yield monitoring and first-order fault diagnosis. The architecture builds on and reuses existing DfT hardware at the core, die, and product level. Its main new component is a die-level wrapper, which can be based on either IEEE Std 1149.1 or IEEE Std 1500. The paper presents a conceptual overview of the architecture, as well as implementation aspects. Experimental results show that the implementation costs are negligible for medium to large diesComputer EngineeringElectrical Engineering, Mathematics and Computer Scienc

Transfer learning for indoor object classification: From images to point clouds

Indoor furniture is of great relevance to building occupants in everyday life. Furniture occupies space in the building, gives comfort, establishes order in rooms and locates services and activities. Furniture is not always static; the rooms can be reorganized according to the needs. Keeping the building models up to date with the current furniture is key to work with indoor environments. Laser scanning technology can acquire indoor environments in a fast and precise way, and recent artificial intelligence techniques can classify correctly the objects that contain. The objective of this work is to study how to minimize the use of point cloud samples in Neural Network training, tedious to label, and replace them with images obtained from online sources. For this, point clouds are converted to images by means of rotations and projections. The conversion of a 3D vector data to a 2D raster allows the use of Convolutional Neural Networks, the achievement of several images for each acquired point cloud object and the combination with images obtained from online sources, such as Google Images. The images have been distributed among the validation and testing training sets following different percentages. The results show that, although point cloud images cannot be completely dispensed within the training set, only 10% of these achieve high accuracy in the classification. GIS Technologi

Automatic detection and characerization of ground occlusions in urban point clouds from mobile laser scanning data

Occlusions accompany serious problems that reduce the applicability of numerous algorithms. The aim of this work is to detect and characterize urban ground gaps based on occluding object. The point clouds for input have been acquired with Mobile Laser Scanning and have been previously segmented into ground, buildings and objects, which have been classified. The method generates various raster images according to segmented point cloud elements, and detects gaps within the ground based on their connectivity and the application of the hit-or-miss transform. The method has been tested in four real case studies in the cities of Vigo and Paris, and an accuracy of 99.6% has been obtained in occlusion detection and labelling. Cars caused 80.6% of the occlusions. Each car occluded an average ground area of 11.9 m2. The proposed method facilitates knowing the percentage of occluded ground, and if this would be reduced in successive multi-temporal acquisitions based on mobility characteristics of each object class.GIS Technologi

3D Pilot: Eindrapport werkgroep Aanbod van 3D geo-informatie

OTB ReseachOTB Research Institute for the Built Environmen

3D pilot: Managementsamenvatting: impressie van een jaar samenwerken

OTB ResearchOTB Research Institute for the Built Environmen

Towards a 3D geo-information standard in the Netherlands

This paper presents the ongoing research project in The Netherlands in which a large number of stakeholders are realising a 3D testbed based on selected use cases and test areas. The findings of the project will result in a Proof of Concept for a 3D Geoinformation standard and a 3D data infrastructure in The Netherlands compatible with international (e.g. CityGML) and national standards.OTB onderzoekOTB Research Institute for the Built Environmen