Modeling, Analysis and Performance Comparison of Two Direct Sampling DCSK Receivers under Frequency Nonselective Fading Channels

Two direct sampling correlator-type receivers for differential chaos shift keying (DCSK) communication systems under frequency non-selective fading channels are proposed. These receivers operate based on the same hardware platform with different architectures. In the first scheme, namely sum-delay-sum (SDS) receiver, the sum of all samples in a chip period is correlated with its delayed version. The correlation value obtained in each bit period is then compared with a fixed threshold to decide the binary value of recovered bit at the output. On the other hand, the second scheme, namely delay-sum-sum (DSS) receiver, calculates the correlation value of all samples with its delayed version in a chip period. The sum of correlation values in each bit period is then compared with the threshold to recover the data. The conventional DCSK transmitter, frequency non-selective Rayleigh fading channel, and two proposed receivers are mathematically modelled in discrete-time domain. The authors evaluated the bit error rate performance of the receivers by means of both theoretical analysis and numerical simulation. The performance comparison shows that the two proposed receivers can perform well under the studied channel, where the performances get better when the number of paths increases and the DSS receiver outperforms the SDS one.

I/Q imbalance in two-way AF relaying: Power allocation and performance analysis

We investigate the performance of dual-hop two-way amplify-and-forward (AF) relaying in the presence of inphase and quadrature-phase imbalance (IQI) at the relay node. In particular, the effective signal-to-interference-plus-noise ratio (SINR) at both sources is derived. These SINRs are used to design an instantaneous power allocation scheme, which maximizes the minimum SINR of the two sources under a total transmit power constraint. The solution to this optimization problem is analytically determined and used to evaluate the outage probability (OP) of the considered two-way AF relaying system. Both analytical and numerical results show that IQI can create fundamental performance limits on two-way relaying, which cannot be avoided by simply improving the channel conditions.

Joint Analysis of Multiple Algorithms and Performance Measures

There has been an increasing interest in the development of new methods using Pareto optimality to deal with multi-objective criteria (for example, accuracy and time complexity). Once one has developed an approach to a problem of interest, the problem is then how to compare it with the state of art. In machine learning, algorithms are typically evaluated by comparing their performance on different data sets by means of statistical tests. Standard tests used for this purpose are able to consider jointly neither performance measures nor multiple competitors at once. The aim of this paper is to resolve these issues by developing statistical procedures that are able to account for multiple competing measures at the same time and to compare multiple algorithms altogether. In particular, we develop two tests: a frequentist procedure based on the generalized likelihood-ratio test and a Bayesian procedure based on a multinomial-Dirichlet conjugate model. We further extend them by discovering conditional independences among measures to reduce the number of parameters of such models, as usually the number of studied cases is very reduced in such comparisons. Data from a comparison among general purpose classifiers is used to show a practical application of our tests.

A 'before and after' study of nursing students' self-assessed competence in identifying the needs of older patients in hospital using an educational workbook.

Background: A core component of nurse education is clinical practice in order to support the development of clinical skills and competence. Assessment and measurement of the clinical competence of nursing students is important to gauge their professional development and educational needs.

Aim: To evaluate the impact of an Older Persons’ Assessment Educational Workbook (OPAEW) and explore second year nursing students’ competence and their opinions and use of the workbook.

Methods: A ‘before and after’ pre-experimental design was undertaken with n=6 second year nursing students. Outcome measures were the Nursing Competencies Questionnaire and the Self-efficacy in Clinical Performance Scale. Content analysis of workbooks and a survey (n=5) of opinions regarding the workbook was undertaken.

Findings: Pre and post test results for the study (n=5) were tested to determine if there was a relationship between changes in the NCQ and SECP repeated measures and use of an OPAEW. Testing identified evidence of a statistically significant difference for both SECP measures (SECP28 p=0.043; SECP7 p=0.042), with no clear statistical evidence of a difference for the NCQ (p=0.08). A weak negative association (NCQ ρ=-0.600 p=0.285; SECP28 ρ=-0.300 p=0.624; SECP7 ρ=-0.205 p=0.741), was found indicating that those participants who scored the lowest scores at the start of the study, benefited most from the workbook.

Content analysis of the OPAEW (n=5) found that 3 of the 5 participants completed all components of the workbook, with a mean of 1051 words used (SD 281.8). Through the survey (n=5) students reported the workbook as a useful guide when undertaking a patient assessment.

Conclusions: The OPAEW showed potential as an intervention to support the development of nursing students’ competence in older person assessment skills.

A 'before and after' study of nursing students' self-assessed competence in identifying the needs of older patients in hospital using an educational workbook.

Background: A core component of nurse education is clinical practice in order to support the development of clinical skills and competence. Assessment and measurement of the clinical competence of nursing students is important to gauge their professional development and educational needs.

Aim: To evaluate the impact of an Older Persons’ Assessment Educational Workbook (OPAEW) and explore second year nursing students’ competence and their opinions and use of the workbook.

Methods: A ‘before and after’ pre-experimental design was undertaken with n=6 second year nursing students. Outcome measures were the Nursing Competencies Questionnaire and the Self-efficacy in Clinical Performance Scale. Content analysis of workbooks and a survey (n=5) of opinions regarding the workbook was undertaken.

Findings: Pre and post test results for the study (n=5) were tested to determine if there was a relationship between changes in the NCQ and SECP repeated measures and use of an OPAEW. Testing identified evidence of a statistically significant difference for both SECP measures (SECP28 p=0.043; SECP7 p=0.042), with no clear statistical evidence of a difference for the NCQ (p=0.08). A weak negative association (NCQ ρ=-0.600 p=0.285; SECP28 ρ=-0.300 p=0.624; SECP7 ρ=-0.205 p=0.741), was found indicating that those participants who scored the lowest scores at the start of the study, benefited most from the workbook.

Content analysis of the OPAEW (n=5) found that 3 of the 5 participants completed all components of the workbook, with a mean of 1051 words used (SD 281.8). Through the survey (n=5) students reported the workbook as a useful guide when undertaking a patient assessment.

Conclusions: The OPAEW showed potential as an intervention to support the development of nursing students’ competence in older person assessment skills.

From Customer-Oriented Strategy to Organizational Financial Performance: The Role of Human Resource Management and Customer-Linking Capability

Drawing on the organizational capabilities literature, the authors developed and tested a model of how supportive human resource management (HRM) improved firms’ financial performance perceived by marketing managers through fostering the implementation of a customer-oriented strategy. Customer-linking capability, which is the capability in managing close customer relationships, indicated the implementation of the customer-oriented strategy. Data collected from two emerging economies – China and Hungary –established that supportive HRM partially mediated the relationship between customer-oriented strategy and customer-linking capability. Customer-linking capability further explained how supportive HRM contributed to perceived financial performance. This study explicates the implication of customer-oriented strategy for HRM and reveals the
importance of HRM in strategy implementation. It also sheds some light on the ‘black box’ between HRM and performance. While making important contributions to the field of strategy, HRM and marketing, this study also offers useful practical implications.