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P-N Learning: Bootstrapping Binary Classifiers by Structural Constraints
Kalal, Zdenek; Matas, Jiří; Mikolajczyk, Krystian
2010 -
This paper shows that the performance of a binary classifier can be significantly improved by the processing of structured unlabeled data, i.e. data are structured if knowing the label of one example restricts the labeling of the others. We propose a novel paradigm for training a binary classifier from labeled and unlabeled examples that we call P-N learning. The learning process is guided by positive (P) and negative (N) constraints which restrict the labeling of the unlabeled set. P-N learning evaluates the classifier on the unlabeled data, identifies examples that have been classified in contradiction with structural constraints and augments the training set with the corrected samples in an iterative process. We propose a theory that formulates the conditions under which P-N learning guarantees improvement of the initial classifier and validate it on synthetic and real data. P-N learning is applied to the problem of on-line learning of object detector during tracking. We show that an accurate object detector can be learned from a single example and an unlabeled video sequence where the object may occur. The algorithm is compared with related approaches and state-of-the-art is achieved on a variety of objects (faces, pedestrians, cars, motorbikes and animals).
Available in digital repository of ČVUT.
P-N Learning: Bootstrapping Binary Classifiers by Structural Constraints
This paper shows that the performance of a binary classifier can be significantly improved by the processing of structured unlabeled data, i.e. data are structured if knowing the label of one example ...
A voting strategy for visual ego-motion from stereo
Obdržálek, Štěpán; Matas, Jiří
2010 -
We present a procedure for egomotion estimation from visual input of a stereo pair of video cameras. The 3D egomotion problem, which has six degrees of freedom in general, is simplified to four dimensions and further decomposed to two two-dimensional subproblems. The decomposition allows us to use a voting strategy to identify the most probable solution, avoiding the random sampling (RANSAC) or other approximation techniques. The input constitutes of image correspondences between consecutive stereo pairs, i.e. feature points do not need to be tracked over time. The experiments show that even if a trajectory is put together as a simple concatenation of frame-to-frame increments, it comes out reliable and precise.
Available in digital repository of ČVUT.
A voting strategy for visual ego-motion from stereo
We present a procedure for egomotion estimation from visual input of a stereo pair of video cameras. The 3D egomotion problem, which has six degrees of freedom in general, is simplified to four ...
Tolerance Design of Curing Process of Electrically Conductive Adhesives
Barto, Seba; Mach, Pavel
2010 -
The work was directed at examination of influence of tolerances of curing process parameters on the tolerances of the resistance and nonlinearity of a current vs. voltage characteristic of adhesive joints. The joints were formed of electrically conductive adhesive with isotropic electrical conductivity of an epoxy type filled with silver flakes. Mathematical models for the resistance and nonlinearity were found using factorial experiments of the type 22. Tolerance design was carried out for these models. It was found that tolerances of the resistance and nonlinearity depend more on the time of curing than on the curing temperature.
Available in digital repository of ČVUT.
Tolerance Design of Curing Process of Electrically Conductive Adhesives
The work was directed at examination of influence of tolerances of curing process parameters on the tolerances of the resistance and nonlinearity of a current vs. voltage characteristic of adhesive ...
Thermomechanical Analysis of a Bulk of Electrically Conductive Adhesive
Bušek, David; Pilarčíková, Ivana; Mach, Pavel
2010 -
Mechanical properties of isotropically conductive adhesives depend not just on the internal structure and composition (amount and type of binder and filler) of the adhesive, but also on chemical processes that are influenced by curing. Thermomechanical analysis allows to distinguish the point when the adhesive is fully cured, it may reveal a difference in mechanical properties after different modifications of the adhesive, it may give a clue to better thermal processing of the adhesive while curing. Thermal analysis of totally nine types of adhesive modifications was performed, particularly the influence of carbon nanotubes addition, silver nanoparticles and colloidal silver was observed. In our tests, both one-component and two-component adhesives were used. The overview of tested adhesives and their modifications is described in table 1.
Available in digital repository of ČVUT.
Thermomechanical Analysis of a Bulk of Electrically Conductive Adhesive
Mechanical properties of isotropically conductive adhesives depend not just on the internal structure and composition (amount and type of binder and filler) of the adhesive, but also on chemical ...
The Ontology based FMEA of Lead Free Soldering Process
Molhanec, Martin; Mach, Pavel; Mensah, David Asamoah Bamfo
2010 -
Paper is directed to improvement of a FMEA (Failure Mode and Effects Analysis) procedure in the field of reflow lead free soldering by the use of an ontology paradigm. Some ontology editor tools, suitable for our intention, are presented. Particular phases of ontology utilization for development of more exact approach to the FMEA procedure of reflow lead free soldering are analyzed. A proposal of a user's guide for the FMEA procedure based on an ontology paradigm is presented. This user's guide is included in university courses Management of Production Quality and Complex Quality Control provided by the Department of Electro-Technology.
Available in digital repository of ČVUT.
The Ontology based FMEA of Lead Free Soldering Process
Paper is directed to improvement of a FMEA (Failure Mode and Effects Analysis) procedure in the field of reflow lead free soldering by the use of an ontology paradigm. Some ontology editor tools, ...
Solderability Measurement of Copper with Different Surface Finishes
Dušek, Karel; Novák, Michal; Mach, Pavel
2010 -
This article deals with solders wettability measurement of materials with different surface finishes, which are commonly used as solder pads on printed circuit board. The measurement was carried out on two type of solders (Sn63Pb37, Sn95,5Ag3,8Cu0,7), two types of fluxes (94-RXZ-M (IPC-ANCI-J-STD-004 - REL0), 323-ITV (C-ANCI-J-STD-004 - REL1)) and as testing material we used one-side plating PCB (FR4) with four types of surface finishes (pasivated copper, H.A.L, immersion tin, chemical gold plating). For the measurement we have used one of the commonly used wettability evaluation methods - wetting balance (meniscograph) method. Wetting balance method measures the wetting force when the test specimen is immersed into the molten solder bath. Wetting force is measured as a function of time and recorded as wetting curve. We marked the wettability, according to the shape of wetting curve, for each testing combination and sorted them into the table.
Available in digital repository of ČVUT.
Solderability Measurement of Copper with Different Surface Finishes
This article deals with solders wettability measurement of materials with different surface finishes, which are commonly used as solder pads on printed circuit board. The measurement was carried out ...
Influence of Curing Process Parameters on Quality of Electrically Conductive Joints
Barto, Seba; Mach, Pavel
2010 -
Curing parameters of electrically conductive adhesives are the temperature and the time. These parameters are recommended by a manufacturer of adhesive. The goal of the work is to find which of these parameters is more important for achievement of the low electrical resistance and low nonlinearity of a current vs. voltage characteristic of an adhesive joint. A method of factorial experiments of the type 22 and Taguchi orthogonal array of the type L4 were used for this study. It was found that the joint resistance is mostly influenced by the curing time, less by the curing temperature and the lowest influence has the interaction of the time/temperature. Nonlinearity is also influenced mostly by the curing time and less by the curing temperature and by the interaction time/temperature.
Available in digital repository of ČVUT.
Influence of Curing Process Parameters on Quality of Electrically Conductive Joints
Curing parameters of electrically conductive adhesives are the temperature and the time. These parameters are recommended by a manufacturer of adhesive. The goal of the work is to find which of these ...
Modification of Adhesive Joints Resistance with Current Pulses
Mach, Pavel; Bušek, David
2010 -
Strips of electrically conductive adhesive were printed on a test PCB. Strips were processed by a standard curing process and then aged at the temperature of 125 oC. One group of samples was aged in an oven; the second group was heated with current pulses of high intensity. Ageing was carried out 150 hours. The frequency, amplitude and pulse duty cycle were changed. The strip resistance was measured by the four-terminal method, the resistance of the contact between strips and pads using the three-terminal method. It was found that the resistance of the strip heated in an oven slowly grew with the time of ageing. The resistance of the samples heated with current pulses first decreased and then started to growth rapidly. The course depended on parameters of the pulses. The reasons of the resistance changes were discussed.
Available in digital repository of ČVUT.
Modification of Adhesive Joints Resistance with Current Pulses
Strips of electrically conductive adhesive were printed on a test PCB. Strips were processed by a standard curing process and then aged at the temperature of 125 oC. One group of samples was aged in ...
Understanding Formal Description of Pitch-Based Input
Poláček, Ondřej; Míkovec, Zdeněk
2010 - English
The pitch-based input (humming, whistling, singing) in acoustic modality has already been studied in several projects. There is also a formal description of the pitch-based input which can be used by designers to define user control of an application. However, as we discuss in this paper, the formal description can contain semantic errors. The aim of this paper is to validate the formal description with designers. We present a tool that is capable of visualizing vocal commands and detecting semantic errors automatically. We have conducted a user study that brings preliminary results on comprehension of the formal description by designers and ability to identify and remove syntactic errors.
Keywords:
Non-verbal Vocal Interaction; Vocal Gesture; Formal Description; User Study
Available in digital repository of ČVUT.
Understanding Formal Description of Pitch-Based Input
The pitch-based input (humming, whistling, singing) in acoustic modality has already been studied in several projects. There is also a formal description of the pitch-based input which can be used by ...
Stability Control of Renewable Energy Sources in Distribution Systems
Tlustý, Josef; Müller, Zdeněk; Valouch, Viktor
2010 - English
Deregulation in the power market has encouraged the move towards distributed generation, where many smaller generating plants located close to major loads are penetrating into interconnected power systems. When the penetration level increases, several other problems will need to be faced and solved. Stability problems may arise, new planning tools will be needed, dispatching of energy sources with typical random production will be necessary, protection systems must be integrated and revised. In order to simulate power system dynamics programmable opened software in Matlab – DynaSolv was developed. The paper describes various principles of penetration synchronous machine type DGS into distribution network. This study provides possible complex analysis view on DGS stability issues, which can answer the possibility of connection.
Keywords:
stability; distributed generation; globally penetrated system; eigenvalues
Available in digital repository of ČVUT.
Stability Control of Renewable Energy Sources in Distribution Systems
Deregulation in the power market has encouraged the move towards distributed generation, where many smaller generating plants located close to major loads are penetrating into interconnected power ...
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