Search results

A novel vision-based relative navigation system (VBRNS) plays an important role in aeronautics and astronautics fields, and the filter is the core of VBRNS. However, most of the existing filtering algorithms used in VBRNS are derived based on Gaussian assumption and disregard the non-Gaussianity of VBRNS. Therefore, a novel robust filtering named as cubature Huber-based filtering (CHF) is proposed and applied to VBRNS to improve the navigation accuracy in non-Gaussian noise case.

Under the Bayesian filter framework, the third-degree cubature rule is used to compute the cubature points which are propagated through state equation, and then the predicted mean and the associated covariance are taken. A combined minimum l₁ and l₂-norm estimation method referred as Huber’s criterion is used to design the measurement update. After that, the vision-based relative navigation model is presented and the CHF is used to integrate the line-of-sight measurements from vision camera with inertial measurement of the follower to estimate the precise relative position, velocity and attitude between two unmanned aerial vehicles. During the design of relative navigation filter, the quaternions are used to represent the attitude and the generalized Rodrigues parameters are used to represent the attitude error. The simulation is conducted to demonstrate the effectiveness of the algorithm.

By this means, the VBRNS could perform better than traditional VBRNS whose filter is designed by Gaussian filtering algorithms. And the simulation results demonstrate that the CHF could exhibit robustness when the system is non-Gaussian. Moreover, the CHF has more accurate estimation and faster rate of convergence than extended Kalman Filtering (EKF) in face of inaccurate initial conditions.

A novel robust nonlinear filtering algorithm named as CHF is proposed and applied to VBRNS based on cubature Kalman filtering (CKF) and Huber’s technique. The CHF could adapt to the non-Gaussian system effectively and perform better than traditional Gaussian filtering such as EKF.

Understanding how and why firms behave differently during re-internationalization has increasingly been at a premium in international business research. The authors conducted a case study of 11 Chinese international small and medium-sized enterprise and explored how they learned and recovered from involuntary de-internationalization. From case data, the “complete” re-internationalizers learned the lessons of foreign market exits more proactively than “partial” re-internationalizers. The complete re-internationalizers adopted internal and external sources of knowledge acquisition, “middle-up-down” information distribution and ambivalent information interpretation, while the partial re-internationalizers relied on internal sources of knowledge, “top-down” or “bottom-up” information distribution and univalent information interpretation. This study contributes by identifying the crucial role of learning processes to complete re-internationalization, which is absent in existing re-internationalization research.

The concept that an organization's actions or inactions constrain or enhance its future options and outcomes and – ultimately – its long-term survival, is here referred to as the organization's viability. Following a dynamic capabilities framework, we identify two communication practices that help develop both transactive memory systems and a firm's long-term viability, information allocation and collective reflexivity, and call for the development of others. We discuss the interrelationship of these two practices as nurturing the development of transactive memory systems critical for organizational long-term viability. We then discuss organizational structures that prompt or constrain the development of these two communication practices – organizational members’ perceived environmental uncertainty, perceptions of time as scarce, feedback cycles between actions and outcomes, and organizational members’ temporal focus – and offer propositions concerning these relationships. We emphasize the relevance of TMS through the exploration of three characteristics of the relationship between TMS and the long-term viability of organizations. Finally, we conclude with recommendations for organizational development practitioners for fostering TMS through the facilitation of sites for collective reflexivity.

Information, whether it is acquired from an external source or generated internally, is subjected to perceptual filters made up of the organization’s norms, procedures, and beliefs that influence what information the organization attends to and ultimately accepts. This paper examines the role which these organizational filters play in unlearning; viewed here as a specialized form of organizational learning. Unlearning is defined as the “process by which firms eliminate old logics and make room for new ones” by Prahalad and Bettis. The author argues that firms which engage in unlearning activities are better able to cast aside established routines in order to replace them with ones that ultimately result in superior value to their customers.

The purpose of this paper is to estimate the contact-consistent object poses during contact-rich manipulation tasks based only on visual sensors.

The method follows a four-step procedure. Initially, the raw object poses are retrieved using the available object pose estimation method and filtered using Kalman filter with nominal model; second, a group of particles are randomly generated for each pose and evaluated the corresponding object contact state using the contact simulation software. A probability guided particle averaging method is proposed to balance the accuracy and safety issues; third, the independently estimated contact states are fused in a hidden Markov model to remove the abnormal contact state observations; finally, the object poses are refined by averaging the contact state consistent particles.

The experiments are performed to evaluate the effectiveness of the proposed methods. The results show that the method can achieve smooth and accurate pose estimation results and the estimated contact states are consistent with ground truth.

This paper proposes a method to obtain contact-consistent poses and contact states of objects using only visual sensors. The method tries to recover the true contact state from inaccurate visual information by fusing contact simulations results and contact consistency assumptions. The method can be used to extract pose and contact information from object manipulation tasks by just observing the demonstration, which can provide a new way for the robot to learn complex manipulation tasks.

This paper aims to contribute to defining the concepts of boundary spanner, gatekeeper and knowledge broker.

A review of the literature covering more than 100 sources.

A review of past research leads to proposing a set of new definitions and also to the detection of six research avenues.

The ability of organizations to recognize, source and integrate key information or knowledge is important for their strategy, innovation and performance over time. Three types of individuals have information gathering and knowledge dissemination roles at the frontier of organizations and groups: boundary spanners, gatekeepers and knowledge brokers. Although research on these individuals is well-developed, we found that in practice, the definitions of the concepts overlap and still need a clarification. So far, no systematic comparison of these roles has been undertaken.

Incubators, as providers of advice and resources, suggest fostering the development of early-idea firms. Literature and practice seem to suggest an ever-increasing amount of incubator support. The creation of business relationships is at the heart of any business development, and this paper addresses whether a laissez-faire incubator fosters the creation of business relationships. The purpose of this paper is to explore the creation of business relationships among incubated firms during and after their time in the incubator along with the roles that these relationships play for the incubated firms.

Empirically, the paper is based on retrospective interviews with representatives of all incubated firms in a university incubator. A total of fifteen interviews were conducted with representatives of the incubated firms, the incubator and its owners, complemented by secondary data sources.

The paper points out three antecedents for business relationship creation: the lack of experience and connections; convenience; and trust based on the interactions with others in the incubator. These antecedents are connected to the roles of transforming businesses and of adaptation in the dyadic relationships. The laissez-faire incubator helped through the learning-by-doing among the incubated firms, which made them focus on business relationship creation from early on.

Most incubator research portrays the unilateral transfer of knowledge from the incubator to the incubated firm, with the latter being a service taker rather than a co-producer. The paper adds knowledge about business relationships among firms in incubators and the roles that these business relationships could play for the firms. The focus on an incubator providing limited support is of high practical relevance, given the trend of incubators facilitating more and more services.

The purpose of this paper is to study the application of advanced computer image processing techniques for flaw detection on flexible printed circuit (FPC) solder.

Texture directionality feature is obtained based on texture gradient, contour's position is extracted and directionality information obtained through analyzing the distribution of directionality. Contour similarity function is established to filter out false contour and keep proper contour, and the solder's location work is accomplished based on reversed contour. After that, a combination of grey and texture gradient's value deviation from reference value is utilized to reflect and describe texture on the solder's surface. Flaw can be distinguished from homogeneous texture background.

The method has been applied to the inspecting system and achieved a higher accuracy and a lower false defect rate. It demonstrates that the method can detect flaws efficiently and effectively.

Although the work on FPC solder's location and flaw detection is presented, defective classification is not involved that is also very important content for inspection.

The paper provides a new way to locate solder based on directionality. The method not only extracts contour feature but also gains directional parameters to help realize accurate location, especially for some solders that are deformed to some extent. Entropy statistic based on distribution of grey and texture gradient is proposed to describe and measure solder's surface texture. The new algorithm performs stably and efficiently and is fit for practical application.

To test empirical relationships between export market information use and export knowledge and export performance.

Confirmatory factor analysis, using LISREL 8.50, based on a postal survey. The setting selected was the Norwegian seafood industry, mainly consisting of a number of small and medium‐sized firms with a strong export dependency.

The results indicate that “instrumental/conceptual” use of information positively affects both export knowledge and export performance, while “symbolic” use does not affect either. Export knowledge is found to have no direct influence on export performance in this study.

For generalisation purposes, longitudinal studies in multiple settings would be preferable to this cross‐sectional survey in a specific setting.

Firms accumulate knowledge and expertise by integrating and incorporating information that has been processed, interpreted and used. This study underscores the importance, for success in export markets, of a commitment to systematically generating, disseminating and responding to export market information. There are clear implications for the management of market intelligence and planning, to enhance the firm's performance.

Provides a better understanding of export market information use and its consequences, by integrating it with the concepts of export knowledge and export performance, and testing their structural relations.

This paper aims to present the estimation of the output voltage of metal oxide semiconductor field effect transistor (MOSFET) using the extended Kalman filter (EKF) method.

The method uses EKF for MOSFET output voltage estimation. To implement the EKF method, the state space model has been obtained using Kirchhoff’s current law and Enz-Krummenacher-Vittoz model of the MOSFET circuit.

The proposed method can be used for any mode of MOSFET operation besides near the quiescent point region. The nonlinearity that occurs in the saturation region of MOSFET can also be considered in the proposed method. The proposed method can also be used for a large input signal. Though Kalman filter can be used for the small amplitude input signal, it results in inaccurate estimation due to the linearization of the nonlinear system.

The method is able to track the parameters when they are slowly changing with time.

The proposed method presents maximal precision of simulation as the maximal precision of simulation requires modeling of the circuit in terms of device parameters and circuit elements.