A Complexity Reduced ML Detector on OFDM-CDM Systems in Mobile Channel

Orthogonal frequency-division multiplexing (OFDM) is one of the most promising techniques for the 4-th generation mobile system. When the OFDM system is applied to cellular environment, it is required to make the transmission scheme robust to other-cell interference (OCI). The use of code division multiplexing (CDM) has been considered to mitigate the OCI in OFDM systems. In cell boundary, it is desirable to design OFDM-CDM transceiver scheme to reduce the effect of OCI. In this paper, we consider transceiver schemes for cell boundary users in the OFDM-CDM downlink. We propose a simplified maximum likelihood (ML) detection scheme that can nearly achieve full ML detection performance. In addition, a new spreading code is proposed for BPSK modulation, yielding a receiver gain of about 1dB regardless of detection schemes. Finally, the performance of the proposed schemes is verified by computer simulation

Fast initialization of equalizers for VSB-based DTV systems in multipath channel

This paper proposes a fast initialization technique for equalization of 8-VSB based digital television (DTV) signal in severe multipath channels. We consider the use of a modified decision feedback equalizer (MDFE) [1,2] for fast initialization. The feedback filter (FBF) of the MDFE can be initialized simply by estimating the channel impulse response and only the feedforward filter (FFF) of the MDFE need training for initialization. To overcome the shortage of the training sequence in the VSB DTV signal, we propose a new initialization method by generating a virtual training signal to initialize the FFF of the MDFE. Simulation results show that the proposed scheme can fast initialize the equalizer using less than 5000 symbols, while providing the receiver performance comparable to that of conventional schemes

Malnutrition and Associated Factors with Nutritional Status among Orphan Children: An Evidence-Based Study from Nepal

Background: Malnutrition is a common public health problem among children in low and middle-income developing countries. Orphan's children are vulnerable and neglected groups in society and are more prone to malnutrition. The study aims to identify the prevalence of underweight, stunting, thinness, and factors associated with nutritional status among orphan children. Methods: Quantitative method & analytical cross-sectional research design were used to assess the nutritional status and its associated factors among orphan children in Pokhara Valley, Nepal. The sample size of 160 children was obtained by a simple random technique. The semi-structured questionnaire, digital bathroom scale, stadiometer was used as the data collection technique. Data management and analysis were done from Epi-info, SPSS 25 version, and WHO Anthro plus. Findings: The majority of children were malnourished (80.6%) with the prevalence of stunting (55.1%), thinness (13.8%), and overweight (6.9%). Prevalence of underweight, stunting, and thinness was high among the boys (85.5%, 26.3%, and 15.8%), but overweight was more prevalent among the girls (7.1%). Ethnicity, sex, age, stay duration in an orphanage, and education of caregivers was associated with the nutritional status of orphan children (p <0.05). Non-privileged children and children below 11 years were more prone to malnutrition. Conclusion: Malnutrition is highly prevalent in orphan children and needs to be addressed. There is still limited study available on the nutritional status of orphan children in Nepal. Nutritional status should be monitored regularly for early identification and timely intervention of malnutrition to promote the nutrition health status of orphan childre

A Framework Design for the Next-Generation Radio Access System

Extensive use of the Internet and huge demands for multimedia services via portable devices require the development of packet-based radio access systems with high transmission efficiency. Advanced radio transmission technologies have recently been proposed to achieve this challenging task. However, few researches have been reported on the design of an integrated system that can efficiently exploit the advantages of these transmission technologies. This paper considers the design of a packet-based cellular system for next-generation radio access. We propose a novel system framework that can incorporate various advanced transmission technologies such as link adaptation, opportunistic packet scheduling, channel coding, and multiantenna techniques. For efficient use of these technologies together, we first investigate the interoperability between these technologies by proposing a so-called cause and effect analysis. Based on this investigation, we design a differentiated-segments-based orthogonal frequency-division multiplexing system, called DiffSeg, to accommodate heterogeneous operating conditions in a seamless manner. Simulation results show that the proposed DiffSeg system can provide a nearly optimum performance with flexible configuration in a wide range of wireless channel conditions

Other-Cell Interference Reducing Resource Allocation in OFDM-Based Asynchronous Cellular Systems

Orthogonal frequency division multiplexing (OFDM) is considered as one of the most promising techniques for next-generation wireless access systems. However, it may suffer from the so-called other-cell interference (OCI) in cellular environments. In this paper, we consider a novel resource allocation scheme to reduce the OCI in OFDM-based asynchronous cellular systems. The proposed scheme can reduce the OCI by exploiting repetitive properties of cyclic prefix of OFDM symbol and asynchronous properties between the user and the base stations in other cells. The proposed scheme can be applied to various types of OFDMbased systems such as orthogonal frequency division multiple access (OFDMA) and multicarrier code division multiple access (MC-CDMA) systems. Simulation results show that the proposed scheme can reduce the OCI by nearly up to 1 dB compared to conventional schemes, yielding an increase of the throughput of about 15% near the cell boundary in OFDM-based asynchronous cellular environments

Efficacy evaluation of combination vaccine of recombinant C-terminal fragments of ApxIA, ApxIIA and ApxIIIA in piglets

The efficacy of the combination vaccine of the individual C-terminal fragments of ApxIA, ApxIIA and ApxIIIA of Actinobacillus pleuropneumoniae (APP) was evaluated in piglets. Twenty piglets were divided equally into 2 groups (n=10). All piglets were intramuscularly primed at 4 week-of-age (0 week post prime inoculation (WPPI)) and were intramuscularly boosted at 6 week-of-age (2 WPPI). Group A piglets were inoculated with sterile PBS and group B piglets were inoculated with the combination vaccine. Concentrations of each of the C-terminal fragment-specific IgG as determined by ELISA were significantly higher in group B than in group A from 2 WPPI until the end of this study. Clinical signs were observed from only 10% of group B piglets after the challenge with the mixture of APP serotypes 1, 2 and 5 at 4 WPPI, while 50% of group A piglets were protected against APP infections. Overall, intramuscular inoculation with the vaccine candidate can efficiently protect piglets against APP infection

Efficacy of Antibiotics Sprayed into Surgical Site for Prevention of the Contamination in the Spinal Surgery

Study DesignRetrospective study.PurposeTo evaluate the effect of intraoperative wound application of vancomycin on preventing surgical wound contamination during instrumented lumbar spinal surgery.Overview of LiteraturePostoperative infection is the one of the most devastating complications of lumbar surgery. There are a few reports showing the benefits of intraoperative wound application of vancomycin during spinal surgery. However, there is no report about the effectiveness of local vancomycin instillation in prevention of surgical wound contamination.MethodsEighty-six patients underwent instrumented lumbar spinal surgery. Mean patient age was 65.19 years (range, 23-83 years). There were 67 females and 19 males. During surgery, vancomycin powder was applied into the surgical site before closure in 43 patients (antibiotic group) and vancomycin powder was not applied into the surgical site before closure in 43 patients (control group). The tip of the surgical drain was cultured to evaluate surgical wound contamination. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured on the first, third, seventh, and fourteenth day after the operation.ResultsWe found two patients with a positive culture from the tip of surgical drains in the antibiotic group, and one patient with a positive culture from the tip of the surgical drain in the control group. Postoperative ESR and CRP levels did not show significant differences between the two groups. On the third postoperative day, ESR in patients of the antibiotic group was more significantly decreased than that in patients of the control group, while CRP level did not show a significant difference between the two groups.ConclusionsThere was no evidence to suggest that intraoperative vancomycin application is effective in decreasing the risk of postoperative wound infection after instrumented posterior lumbar fusion surgery