Matching Process (matching + process)

Distribution by Scientific Domains


Selected Abstracts


Did the Hartz Reforms Speed-Up the Matching Process?

GERMAN ECONOMIC REVIEW, Issue 3 2009
A Macro-Evaluation Using Empirical Matching Functions
Empirical matching function; stock-flow matching; Hartz reform Abstract. Starting in January 2003, Germany implemented the first two so-called Hartz reforms, followed by the third and fourth packages of Hartz reforms in January 2004 and January 2005, respectively. The aim of these reforms was to accelerate labor market flows and reduce unemployment duration. Without attempting to evaluate the specific components of these Hartz reforms, this paper provides a first attempt to evaluate the overall effectiveness of the first two reform waves, Hartz I/II and III, in speeding up the matching process between unemployed and vacant jobs. The analysis is conceptually rooted in the flow-based view underlying the reforms, estimating the structural features of the matching process. The results indicate that the reforms indeed had an impact in making the labor market more dynamic and accelerating the matching process. [source]


An Economic Model of Friendship: Homophily, Minorities, and Segregation

ECONOMETRICA, Issue 4 2009
Sergio Currarini
We develop a model of friendship formation that sheds light on segregation patterns observed in social and economic networks. Individuals have types and see type-dependent benefits from friendships. We examine the properties of a steady-state equilibrium of a matching process of friendship formation. We use the model to understand three empirical patterns of friendship formation: (i) larger groups tend to form more same-type ties and fewer other-type ties than small groups, (ii) larger groups form more ties per capita, and (iii) all groups are biased towards same-type relative to demographics, with the most extreme bias coming from middle-sized groups. We show how these empirical observations can be generated by biases in preferences and biases in meetings. We also illustrate some welfare implications of the model. [source]


Evidence from proprioception of fusimotor coactivation during voluntary contractions in humans

EXPERIMENTAL PHYSIOLOGY, Issue 3 2008
Trevor J. Allen
In experiments on position sense at the elbow joint in the horizontal plane, blindfolded subjects were required to match the position of one forearm (reference) by placement of their other arm (indicator). Position errors were measured after conditioning elbow muscles of the reference arm with an isometric contraction while the arm was held either flexed or extended. The difference in errors after the two forms of conditioning was large when the conditioned muscles remained relaxed during the matching process and it became less when elbow muscles were required to lift a load during the match (10 and 25% of maximal voluntary contraction, respectively). Errors from muscle conditioning were attributed to signals arising in muscle spindles and were hypothesized to result from the thixotropic property of passive intrafusal fibres. Active muscle does not exhibit thixotropy. It is proposed that during a voluntary contraction the errors after conditioning are less, because the spindles become coactivated through the fusimotor system. The distribution of errors is therefore seen to be a reflection of fusimotor recruitment thresholds. For elbow flexors most, but not all, fusimotor fibres appear to be recruited by 10% of a maximal contraction. [source]


Colon segmentation and colonic polyp detection using cellular neural networks and three-dimensional template matching

EXPERT SYSTEMS, Issue 5 2009
Niyazi Kilic
Abstract: In this study, an automatic three-dimensional computer-aided detection system for colonic polyps was developed. Computer-aided detection for computed tomography colonography aims at facilitating the detection of colonic polyps. First, the colon regions of whole computed tomography images were carefully segmented to reduce computational burden and prevent false positive detection. In this process, the colon regions were extracted by using a cellular neural network and then the regions of interest were determined. In order to improve the segmentation performance of the study, weights in the cellular neural network were calculated by three heuristic optimization techniques, namely genetic algorithm, differential evaluation and artificial immune system. Afterwards, a three-dimensional polyp template model was constructed to detect polyps on the segmented regions of interest. At the end of the template matching process, the volumes geometrically similar to the template were emhanced. [source]


Did the Hartz Reforms Speed-Up the Matching Process?

GERMAN ECONOMIC REVIEW, Issue 3 2009
A Macro-Evaluation Using Empirical Matching Functions
Empirical matching function; stock-flow matching; Hartz reform Abstract. Starting in January 2003, Germany implemented the first two so-called Hartz reforms, followed by the third and fourth packages of Hartz reforms in January 2004 and January 2005, respectively. The aim of these reforms was to accelerate labor market flows and reduce unemployment duration. Without attempting to evaluate the specific components of these Hartz reforms, this paper provides a first attempt to evaluate the overall effectiveness of the first two reform waves, Hartz I/II and III, in speeding up the matching process between unemployed and vacant jobs. The analysis is conceptually rooted in the flow-based view underlying the reforms, estimating the structural features of the matching process. The results indicate that the reforms indeed had an impact in making the labor market more dynamic and accelerating the matching process. [source]


Covance's global mentoring initiative develops people through exceptional partnerships

GLOBAL BUSINESS AND ORGANIZATIONAL EXCELLENCE, Issue 1 2006
Miriam Darmstadter
The global mentoring program at Covance plays a dual role as a diversity initiative and a resource-efficient developmental tool, providing a powerful developmental experience that enriches worklife for all participants. After studying successful programs in leading companies, the Covance team crafted a program that includes selection criteria and a careful matching process, training and tools for mentoring pairs, ongoing support, and close monitoring and evaluation. The company has also tackled the challenges of long-distance mentoring relationships to make the program more accessible to its global workforce. As the program continues to grow and receive rave reviews, the Covance team continues to refine it for even greater effectiveness. © 2006 Wiley Periodicals, Inc. [source]


Fast template matching using correlation-based adaptive predictive search

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 3 2003
Shijun Sun
Abstract We have developed the Correlation-based Adaptive Predictive Search (CAPS) as a fast search strategy for multidimensional template matching. A 2D template is analyzed, and certain characteristics are computed from its autocorrelation. The extracted information is then used to speed up the search procedure. This method provides a significant improvement in computation time while retaining the accuracy of traditional full-search matching. We have extended CAPS to three and higher dimensions. An example of the third dimension is rotation where rotated targets can be located while again substantially reducing the computational requirements. CAPS can also be applied in multiple steps to further speed up the template matching process. Experiments were conducted to evaluate the performance of 2D, 3D, and multiple-step CAPS algorithms. Compared to the conventional full-search method, we achieved speedup ratios of up to 66.5 and 145 with 2D and 3D CAPS, respectively. © 2003 Wiley Periodicals, Inc. Int J Imaging Syst Technol 13, 169,178, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10055 [source]


A strategy of matching blocks at multi-levels

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 10 2002
Seok-Woo Jang
We propose a size-variable block-matching algorithm for motion-vector estimation. The proposed algorithm dynamically determines the search area and the size of a block. We exploit the constraint of small velocity changes of a block through time to determine the origin of the search area. The range of the search area is adjusted according to the motion coherency of spatially neighboring blocks. The process of determining the size of a block begins with the matching of a small block. If the matching degree is not good enough, we expand the size of the block slightly and then repeat the matching process until our matching criterion is satisfied. The experimental results show that the proposed algorithm can yield very accurate block motion vectors. © 2002 Wiley Periodicals, Inc. [source]


Two-dimensional occluded object matching using petri nets

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 3 2002
Chuan Zhou
This article discusses the use of Petri nets to model the process of object matching between an image and a model under different two-dimensional geometric transformations. This transformation finds its applications in sensor-based robot control, flexible manufacturing systems, industrial inspection, and so on. Its topological structure relation, called point-line relation structure (PLRS), presents a Petri net-based description approach for object structure. It has been shown how Petri nets can be used to model the matching process, and an optimal or near optimal matching can be obtained by tracking the reachability graph of the net. The experiment result shows that objects can be successfully identified and located under two-dimensional transformation such as translations, rotations, scale changes, and distortions due to partial object occlusion. © 2002 Wiley Periodicals, Inc. [source]


A structural model of US aggregate job flows

JOURNAL OF APPLIED ECONOMETRICS, Issue 3 2002
Fabrice Collard
This paper contributes to the analysis of jobs flows dynamics through the explicit modelling of job creations and job destructions. We propose a simple matching model extended for endogenous separation and tractable heterogeneity. The parameters of the model are estimated using a simulation-based estimation method. We then test the ability of trade externalities, generated by the matching process, to (i) propagate reallocation and aggregate disturbances in the whole labor market and (ii) generate the observed distribution of aggregate job flows. The results clearly indicate that the model is able to match the dynamics of US aggregate job flows. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Investigation of in vivo 6DOF total knee arthoplasty kinematics using a dual orthogonal fluoroscopic system

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006
George R. Hanson
Abstract Fluoroscopic techniques have been recently used to detect in vivo knee joint kinematics. This article presents a technique that uses two fluoroscopes to form a dual orthogonal fluoroscopic system for accurately measuring in vivo 6DOF total knee arthoplasty (TKA) kinematics. The system was rigorously validated and used to investigate in vivo kinematics of 12 patients after cruciate-retaining TKA. In a repeatability study, the pose of two different TKA components was reproduced with standard deviations (SD) of 0.17 mm and 0.57° about all three axes. In an accuracy study, the reproduced component positions were compared to the known component positions. Position and rotation mean errors were all within 0.11 mm and 0.24°, with SD within 0.11 mm and 0.48°, respectively. The results of this study show that the matching process of the imaging system is able to accurately reproduce the spatial positions and orientations of both the femoral and tibial components. For CR TKA patients, a consistent anterior femoral translation was observed with flexion through 45° of flexion, and thereafter, the femur translated posteriorly with further flexion. The medial,lateral translation was measured to be less than 2 mm throughout the entire flexion range. Internal tibial rotation steadily increased through maximum flexion by approximately 6°. Varus rotation was also measured with flexion but had a mean magnitude less than 2.0°. In conclusion, the dual orthogonal fluoroscopic system accurately detects TKA kinematics and is applicable towards other joints of the musculoskeletal system, including the wrist, elbow, shoulder, ankle, and spine. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


Ultrafast Raman loss spectroscopy

JOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2009
Siva Umapathy
Abstract This paper deals with a new form of nonlinear Raman spectroscopy called ,ultrafast Raman loss spectroscopy (URLS)'. URLS is analogous to stimulated Raman spectroscopy (SRS) but is much more sensitive than SRS. The signals are background (noise) free unlike in coherent anti-Stokes Raman spectroscopy (CARS) and it provides natural fluorescence rejection, which is a major problem in Raman spectroscopy. In addition, being a self-phase matching process, the URLS experiment is much easier than CARS, which requires specific phase matching of the laser pulses. URLS is expected to be alternative if not competitive to CARS microscopy, which has become a popular technique in applications to materials, biology and medicine. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Survival of patients with nonmetastatic pT3 renal tumours: a matched comparison of laparoscopic vs open radical nephrectomy

BJU INTERNATIONAL, Issue 11 2009
Karim Bensalah
OBJECTIVES To compare the oncological outcome of patients with pT3 renal tumours treated either by laparoscopic radical nephrectomy (LRN) or open RN (ORN). PATIENTS AND METHODS In a retrospective review of a multi-institutional database, we identified 1003 patients with a T3N0M0 renal tumour and with no vena caval invasion. Sixty-five patients treated by LRN were matched with up to four patients treated by ORN. Exact matches were made for age, gender, tumour size, perirenal fat invasion, renal vein invasion, and histological subtype. Following the matching process there were 44 patients treated by LRN and 135 by ORN. Qualitative and continuous variables were compared using chi-square and independent-sample t -tests, respectively. Differences in survival were compared using the Kaplan-Meier method. A Cox regression model was used to test the effect of variables on survival. RESULTS The two groups were comparable for age (P = 0.4), gender, tumour size (P = 0.4), tumour grade (P = 0.25) and histological subtype (P = 0.45). The mean follow-up was longer in the ORN group (55 vs 28 months, P < 0.001). There was no difference in survival between the ORN and LRN groups in the whole T3 population (P = 0.7), in those with perirenal fat invasion (P = 0.9), or in the subset with renal vein invasion (P = 0.31). In univariate analysis, the only predictor for death from cancer was tumour grade (P = 0.05). In multivariate analysis, no variable was significantly associated with cancer survival. CONCLUSIONS LRN has no adverse effect on cancer survival compared to ORN in patients with microscopic T3 renal cancer. Additional prospective evaluation is warranted. [source]