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Falk Leichsenring - One of the best experts on this subject based on the ideXlab platform.
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comparative effects of short term psychodynamic psychotherapy and cognitive behavioral therapy in depression a meta Analytic approach
Clinical Psychology Review, 2001Co-Authors: Falk LeichsenringAbstract:This article reviews the efficacy of short-term psychodynamic psychotherapy (STPP) in depression compared to cognitive-behavioral therapy (CBT) or behavioral therapy (BT). In this review, only studies in which at least 13 therapy sessions were performed have been included, and a sufficient number of patients per group were treated (N $ 20). With regard to outcome criteria, the results were reviewed for improvements in depressive symptoms, general psychiatric symptoms, and social functioning. Six studies met the inclusion criteria. Results: In 58 of the 60 comparisons (97%) performed in the six studies and their follow-ups, no significant difference could be detected between STPP and CBT/BT concerning the effects in depressive symptoms, general psychiatric symptomatology, and social functioning. Furthermore, STPP and CBT/BT did not differ signifi- cantly with regard to the patients that were judged as remitted or improved. According to a meta- Analytic Procedure described by R. Rosenthal (1991) the studies do not differ significantly with re- gard to the patients that were judged as remitted or improved after treatment with STPP or CBT/ BT. The mean difference between STPP and CBT/BT concerning the number of patients that were judged as remitted or improved corresponds to a small effect size (post-assessment: f 5 0.08, fol- low-up assessment: f 5 0.12). Thus, STPP and CBT/BT seem to be equally effective methods in the treatment of depression. However, because of the small number of studies which met the inclu- sion criteria, this result can only be preliminary. Furthermore, it applies only to the specific forms of STPP that were examined in the selected studies and cannot be generalized to other forms of STPP. Further studies are needed to examine the effects of specific forms of STPP in both controlled and naturalistic settings. Furthermore, there are findings indicating that 16-20 sessions of both STPP and CBT/BT are insufficient for most patients to achieve lasting remission. Future studies should address the effects of longer treatments of depression. © 2001 Elsevier Science Ltd.
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comparative effects of short term psychodynamic psychotherapy and cognitive behavioral therapy in depression a meta Analytic approach
Clinical Psychology Review, 2001Co-Authors: Falk LeichsenringAbstract:This article reviews the efficacy of short-term psychodynamic psychotherapy (STPP) in depression compared to cognitive-behavioral therapy (CBT) or behavioral therapy (BT). In this review, only studies in which at least 13 therapy sessions were performed have been included, and a sufficient number of patients per group were treated (N $ 20). With regard to outcome criteria, the results were reviewed for improvements in depressive symptoms, general psychiatric symptoms, and social functioning. Six studies met the inclusion criteria. Results: In 58 of the 60 comparisons (97%) performed in the six studies and their follow-ups, no significant difference could be detected between STPP and CBT/BT concerning the effects in depressive symptoms, general psychiatric symptomatology, and social functioning. Furthermore, STPP and CBT/BT did not differ signifi- cantly with regard to the patients that were judged as remitted or improved. According to a meta- Analytic Procedure described by R. Rosenthal (1991) the studies do not differ significantly with re- gard to the patients that were judged as remitted or improved after treatment with STPP or CBT/ BT. The mean difference between STPP and CBT/BT concerning the number of patients that were judged as remitted or improved corresponds to a small effect size (post-assessment: f 5 0.08, fol- low-up assessment: f 5 0.12). Thus, STPP and CBT/BT seem to be equally effective methods in the treatment of depression. However, because of the small number of studies which met the inclu- sion criteria, this result can only be preliminary. Furthermore, it applies only to the specific forms of STPP that were examined in the selected studies and cannot be generalized to other forms of STPP. Further studies are needed to examine the effects of specific forms of STPP in both controlled and naturalistic settings. Furthermore, there are findings indicating that 16-20 sessions of both STPP and CBT/BT are insufficient for most patients to achieve lasting remission. Future studies should address the effects of longer treatments of depression. © 2001 Elsevier Science Ltd.
A P Liavas - One of the best experts on this subject based on the ideXlab platform.
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Efficient computation of the binary vector that maximizes a rank-deficient quadratic form
2010Co-Authors: George N Karystinos, A P LiavasAbstract:The maximization of a full-rank quadratic form over a finite alphabet is NP-hard in both a worst-case sense and an average sense. Interestingly, if the rank of the form is not a function of the problem size, then it can be maximized in polynomial time. An algorithm for the efficient computation of the binary vector that maximizes a rank-deficient quadratic form is developed based on an Analytic Procedure. Auxiliary spherical coordinates are introduced and the multi-dimensional space is partitioned into a polynomial-size set of regions; each region corresponds to a distinct binary vector. The binary vector that maximizes the rank-deficient quadratic form is shown to belong to the polynomial-size set of candidate vectors. Thus, the size of the feasible set is efficiently reduced from exponential to polynomial. Index Terms — Optimization. 1
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efficient computation of the binary vector that maximizes a rank deficient quadratic form
International Conference on Acoustics Speech and Signal Processing, 2008Co-Authors: George N Karystinos, A P LiavasAbstract:The maximization of a full-rank quadratic form over a finite alphabet is NP-hard in both a worst-case sense and an average sense. Interestingly, if the rank of the form is not a function of the problem size, then it can be maximized in polynomial time. An algorithm for the efficient computation of the binary vector that maximizes a rank-deficient quadratic form is developed based on an Analytic Procedure. Auxiliary spherical coordinates are introduced and the multi-dimensional space is partitioned into a polynomial-size set of regions; each region corresponds to a distinct binary vector. The binary vector that maximizes the rank-deficient quadratic form is shown to belong to the polynomial-size set of candidate vectors. Thus, the size of the feasible set is efficiently reduced from exponential to polynomial.
Dirk Van Den Poel - One of the best experts on this subject based on the ideXlab platform.
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joint optimization of customer segmentation and marketing policy to maximize long term profitability
Expert Systems With Applications, 2004Co-Authors: Jedidjah Jonker, Nanda Piersma, Dirk Van Den PoelAbstract:Abstract With the advent of one-to-one marketing media, e.g. targeted direct mail or internet marketing, the opportunities to develop targeted marketing (customer relationship management) campaigns are enhanced in such a way that it is now both organizationally and economically feasible to profitably support a substantially larger number of marketing segments. However, the problem of what segments to distinguish, and what actions to take towards the different segments increases substantially in such an environment. A systematic Analytic Procedure optimizing both steps would be very welcome. In this study, we present a joint optimization approach addressing two issues: (1) the segmentation of customers into homogeneous groups of customers, (2) determining the optimal policy (i.e. what action to take from a set of available actions) towards each segment. We implement this joint optimization framework in a direct-mail setting for a charitable organization. Many previous studies in this area highlighted the importance of the following variables: R(ecency), F(requency), and M(onetary value). We use these variables to segment customers. In a second step, we determine which marketing policy is optimal using markov decision processes, following similar previous applications. The attractiveness of this stochastic dynamic programming Procedure is based on the long-run maximization of expected average profit. Our contribution lies in the combination of both steps into one optimization framework to obtain an optimal allocation of marketing expenditures. Moreover, we control segment stability and policy performance by a bootstrap Procedure. Our framework is illustrated by a real-life application. The results show that the proposed model outperforms a CHAID segmentation.
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joint optimization of customer segmentation and marketing policy to maximize long term profitability
Econometric Institute Research Papers, 2002Co-Authors: Jedidjah Jonker, Nanda Piersma, Dirk Van Den PoelAbstract:With the advent of one-to-one marketing media, e.g. targeted direct mail or internet marketing, the opportunities to develop targeted marketing campaigns are enhanced in such a way that it is now both organizationally and economically feasible to profitably support a substantially larger number of marketing segments. However, the problem of what segments to distinguish, and what actions to take towards the different segments increases substantially in such an environment. A systematic Analytic Procedure optimizing both steps would be very welcome.In this study, we present a joint optimization approach addressing two issues: (1) the segmentation of customers into homogeneous groups of customers, (2) determining the optimal policy (i.e., what action to take from a set of available actions) towards each segment. We implement this joint optimization framework in a direct-mail setting for a charitable organization. Many previous studies in this area highlighted the importance of the following variables: R(ecency), F(requency), and M(onetary value). We use these variables to segment customers. In a second step, we determine which marketing policy is optimal using markov decision processes, following similar previous applications. The attractiveness of this stochastic dynamic programming Procedure is based on the long-run maximization of expected average profit. Our contribution lies in the combination of both steps into one optimization framework to obtain an optimal allocation of marketing expenditures. Moreover, we control segment stability and policy performance by a bootstrap Procedure. Our framework is illustrated by a real-life application. The results show that the proposed model outperforms a CHAID segmentation.
Martin S Hagger - One of the best experts on this subject based on the ideXlab platform.
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using meta Analytic path analysis to test theoretical predictions in health behavior an illustration based on meta analyses of the theory of planned behavior
Preventive Medicine, 2016Co-Authors: Martin S Hagger, Derwin K C Chan, Cleo Protogerou, Nikos L D ChatzisarantisAbstract:Abstract Objective Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-Analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate our points by conducting new analyses of two meta-analyses of a popular theory applied to health behaviors, the theory of planned behavior. Method We conducted meta-Analytic path analyses of the theory in two behavioral contexts (alcohol and dietary behaviors) using data from the primary studies included in the original meta-analyses augmented to include intercorrelations among constructs and relations with past behavior missing from the original analysis. Results Findings supported the nomological validity of the theory and its hypotheses for both behaviors, confirmed important model processes through mediation analysis, demonstrated the attenuating effect of past behavior on theory relations, and provided estimates of the unique effects of theory constructs independent of past behavior. Conclusions Our analysis illustrates the importance of conducting a simultaneous test of theory-stipulated effects in meta-analyses of social cognitive theories applied to health behavior. We recommend researchers adopt this Analytic Procedure when synthesizing evidence across primary tests of social cognitive theories in health.
George N Karystinos - One of the best experts on this subject based on the ideXlab platform.
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Efficient computation of the binary vector that maximizes a rank-deficient quadratic form
2010Co-Authors: George N Karystinos, A P LiavasAbstract:The maximization of a full-rank quadratic form over a finite alphabet is NP-hard in both a worst-case sense and an average sense. Interestingly, if the rank of the form is not a function of the problem size, then it can be maximized in polynomial time. An algorithm for the efficient computation of the binary vector that maximizes a rank-deficient quadratic form is developed based on an Analytic Procedure. Auxiliary spherical coordinates are introduced and the multi-dimensional space is partitioned into a polynomial-size set of regions; each region corresponds to a distinct binary vector. The binary vector that maximizes the rank-deficient quadratic form is shown to belong to the polynomial-size set of candidate vectors. Thus, the size of the feasible set is efficiently reduced from exponential to polynomial. Index Terms — Optimization. 1
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efficient computation of the binary vector that maximizes a rank deficient quadratic form
International Conference on Acoustics Speech and Signal Processing, 2008Co-Authors: George N Karystinos, A P LiavasAbstract:The maximization of a full-rank quadratic form over a finite alphabet is NP-hard in both a worst-case sense and an average sense. Interestingly, if the rank of the form is not a function of the problem size, then it can be maximized in polynomial time. An algorithm for the efficient computation of the binary vector that maximizes a rank-deficient quadratic form is developed based on an Analytic Procedure. Auxiliary spherical coordinates are introduced and the multi-dimensional space is partitioned into a polynomial-size set of regions; each region corresponds to a distinct binary vector. The binary vector that maximizes the rank-deficient quadratic form is shown to belong to the polynomial-size set of candidate vectors. Thus, the size of the feasible set is efficiently reduced from exponential to polynomial.